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Transcript of DRAKENSTEIN MUNICIPALITY - fewlbnexus.uct.ac.za · drakenstein municipality waste water risk...
DRAKENSTEIN MUNICIPALITY
WASTE WATER RISK ABATEMENT PLAN (W2RAP)
REVISION B
FEBRUARY 2013 Prepared by : Prepared for : LYNERS CONSULTING ENGINEERS
DRAKENSTEIN MUNICIPALITY
AND PROJECT MANAGERS P O BOX 1 P O BOX 79 MAIN STREET PAARL MAIN STREET PAARL 7622 7622 TEL : (021) 872 3564 TEL : (021) 807 4500 FAX : (021) 872 0619 FAX : (021) 872 8054
Revision History
Revision No.
Prepared by Description Date
Draft A Lyners Draft of W2RAP 7 October 2011
Draft B Lyners Draft of W2RAP 1 February 2013
Document Acceptance
Action Name Signed Date
Prepared by Lyners
Reviewed by R Brown
Approved by R Brown
(i)
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Table of Contents
1 INTRODUCTION................................................................................................................................... 1
2 DESCRIPTION OF W2RAP TEAM ....................................................................................................... 1
2.1 Duties of team and commitment ........................................................................................................ 1
3 DESCRIPTION OF VARIOUS WORKS ............................................................................................... 3
3.1 Paarl WWTW ..................................................................................................................................... 3
3.1.1 Catchment ...................................................................................................................................... 3
3.1.2 Collection ....................................................................................................................................... 3
3.1.3 Treatment ....................................................................................................................................... 3
3.2 Wellington WWTW ............................................................................................................................. 4
3.2.1 Catchment ...................................................................................................................................... 4
3.2.2 Collection ....................................................................................................................................... 4
3.2.3 Treatment ....................................................................................................................................... 5
3.3 Pearl Valley WWTW .......................................................................................................................... 5
3.3.1 Catchment ...................................................................................................................................... 5
3.3.2 Collection ....................................................................................................................................... 5
3.3.3 Treatment ....................................................................................................................................... 6
3.4 Saron WWTW .................................................................................................................................... 6
3.4.1 Catchment ...................................................................................................................................... 6
3.4.2 Collection ....................................................................................................................................... 7
3.4.3 Treatment ....................................................................................................................................... 7
3.5 Hermon WWTW ................................................................................................................................. 7
3.5.1 Catchment ...................................................................................................................................... 7
3.5.2 Collection ....................................................................................................................................... 8
3.5.3 Treatment ....................................................................................................................................... 8
3.6 Gouda WWTW ................................................................................................................................... 8
3.6.1 Catchment ...................................................................................................................................... 8
3.6.2 Collection ....................................................................................................................................... 8
3.6.3 Treatment ....................................................................................................................................... 8
4 HAZARD ASSESSMENT ...................................................................................................................... 9
4.1 Risk Matrix used ................................................................................................................................ 9
4.2 Hazard Analysis of works ................................................................................................................ 11
4.3 Paarl WWTW ................................................................................................................................... 11
4.4 Pearl Valley WWTW ........................................................................................................................ 15
4.5 Wellington WWTW ........................................................................................................................... 17
4.6 Hermon WWTW ............................................................................................................................... 21
4.7 Saron WWTW .................................................................................................................................. 22
4.8 Gouda WWTW ................................................................................................................................. 26
5 CONTROL MEASUREMENTS ........................................................................................................... 29
6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL ................................... 31
6.1 Operational Alert Levels .................................................................................................................. 32
6.2 Verification of functioning of W2RAP ............................................................................................... 32
(ii)
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7 SUPPORT PROGRAMMES ............................................................................................................... 33
7.1 Process Controller Training Provided .............................................................................................. 33
7.2 Supervisors Forum .......................................................................................................................... 33
7.3 Career Pathing ................................................................................................................................. 33
7.4 Consultant Advisors ......................................................................................................................... 33
8 INCIDENT MANAGEMENT PLAN ...................................................................................................... 33
9 CONCLUSIONS .................................................................................................................................. 36
10 RECOMMENDATIONS ....................................................................................................................... 36
10.1 Risks to be addressed ..................................................................................................................... 36
10.2 Way forward ..................................................................................................................................... 36
ANNEXURES : ANNEXURE A : CATCHMENTS
ANNEXURE B : FLOW DIAGRAMMES
ANNEXURE C : DRAKENSTEIN MUNICIPALITY : WWTW RISK ASSESSMENT
ANNEXURE D : DRAKENSTEIN MUNICIPALITY : WASTE WATER INCIDENT MANAGEMENT PROTOCOL
ANNEXURE E : HIGH AND MEDIUM RISK ITEMS FOR WWTW WITH MITIGATION MEASURES
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1 INTRODUCTION
Drakenstein Municipality currently (year 2013) provides Waste Water Treatment to six (6) communities within it’s municipal boundaries amounting to approximately 240 000 residents. Of the six Waste Water Treatment Works (WWTW), four are activated sludge works and two are evaporation pond systems. Drakenstein Municipality currently experiences challenges with regards to WWTW operation and maintenance which include :
- Aging Infrastructure (Sections of Paarl WWTW were upgraded in the 1960’s)
- Relatively low Operational & Maintenance Budgets for WWTW’s
- Large funding shortfalls for upgrading of existing infrastructure and construction of new infrastructure or technologies.
- Skill shortages in WWTW management and operations
- Large increases in flow volumes due to increasing housing developments; and
- Erratic power supply from national providers.
Given these challenges, it is imperative to follow a risk based management method to risks in the treatment process and identify priority risk areas for inclusion in limited Operational & Maintenance- and Capital upgrading budgets. To this end Drakenstein Municipality has developed a Waste Water Risk Abatement Plan (W
2RAP)
to identify potential risks and mitigation measures for each risk. This document is a living document which will be reviewed and amended constantly as and when the risk situation changes. This document provides an overview of the risks faced by the Drakenstein Municipality and must be considered in conjunction with the other reference documents such as the Green Wastewater Performance Audit Report (November 2012) and the Sewer Master Plan (December 2012).
2 DESCRIPTION OF W
2RAP TEAM
2.1 Duties of team and commitment
The W2RAP team is a multi disciplinary team consisting of team members with intimate knowledge
of the Waste Water Treatment system and the receiving environment. A diagramme showing the composition of this team is shown in figure 2.1 below.
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Figure 2.1 : Diagramme of W
2RAP Team
As the W2RAP is a living document, it is expected that the members of the team provide continual
feedback on the implementation of the system as well as potential improvement. The W
2RAP is a management tool designed to assist policy makers in decision making with regards
to Waste Water Treatment. Drakenstein Municipality owns and manages a total of six (6) WWTW’s and collection systems, namely:
• Paarl Wastewater Treatment and Collection System
• Wellington Wastewater Treatment and Collection System
• Pearl Valley/Val de Vie Wastewater Treatment and Collection System (also known as the Kliprug Wastewater Treatment Plant)
• Saron Wastewater Treatment and Collection System
• Gouda Wastewater Treatment and Collection System
• Hermon Wastewater Treatment and Collection System
Team Leader
Mr R Brown Head of Waste Services Drakenstein Municipality
Compilers
Mr H Mulder (Civil Engineer) and Mr M Filippi (Prof. Civil Engineer and Project Manager)
Private Entities
Berg River Irrigation Board
Information Sources
Mr C Morkel (Supervisor on all Drakenstein WWTW’s)
Various Process controllers for each WWTW
Department of Water Affairs (DWA)
Legislative Bodies
Consultants including WorleyParsons (Green Wastewater Performance Audit), Aurecon and Lyners (Various WWTW’s) AL Abbott Laboratories (Process Auditing) Virtual Consulting Engineers (Saron WWTW) Integral Laboratories (All WWTW’s)
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3 DESCRIPTION OF VARIOUS WORKS 3.1 Paarl WWTW 3.1.1 Catchment
The Paarl WWTW Services a vast section of the Paarl area, from the Bo-Dal Josafat Area to the Paarl South Area, including the areas of Mbekweni and Silvertown to the north. The WWTW is situated next to the Berg River, into which final effluent is discharged. The WWTW is a Class C WWTW under the DWA classifications and currently (2013) has a capacity of 27Mℓ/d, receives and Average Daily Dry Weather Flow (ADDWF) of approximately 22Mℓ/d and is licensed by a water usage permit (No 1222B). A layout of the Paarl WWTW catchment is shown in drawing no 0828/C/002 in Annexure A. The receiving environment is the Berg River. The final effluent must comply with the requirements of the Water Act and for Paarl WWTW these are General Standard. In the near future however the WWTW may need to comply with the Special Standards.
3.1.2 Collection
Influent is conveyed to the Paarl WWTW through various gravity bulk sewers mainly along the Berg River from South to North. The main sewers include the domestic outfall sewer and the industrial outfall sewer. The Bulk Sewer to Southern Paarl currently under construction will serve as a further domestic bulk sewer addressing capacity shortfalls in the existing domestic bulk sewer and providing for future developments in the south of Paarl. Furthermore there are several sewage pumping stations in the catchment that convey sewage via rising mains to the Paarl WWTW which include the following pumping stations shown in table 3.1 below.
Table 3.1 : Sewage Pumping Stations within Paarl
Name of Pumping Station Pumping station to/into
Paarl South Pumping Station No 1 & 2
Existing Domestic Outfall Sewer
Boschenmeer Existing Domestic Outfall Sewer
Roodeberg Existing Domestic Outfall Sewer
Carletta Collector Sewer draining to the Existing Domestic Outfall Sewer
Kaplan Street Collector Sewer draining to the Existing Domestic Outfall Sewer
Dal Josafat Directly to the inlet works of the WWTW
Mbekweni Directly to the inlet works of the WWTW
Silvertown Collection Sewer draining to Mbekweni Pumping Station
Most of the reticulation infrastructure is relatively old, but in good condition. The Asset Management Register of Drakenstein Municipality estimates that approximately 47,6% of the value (useful life) of the sewage network has been consumed. Not withstanding this, the network is continually refurbished/upgraded to replace old infrastructure.
3.1.3 Treatment
The Paarl WWTW comprises a combination of trickling filters (biofilters) and activated sludge processes, with maturation ponds for tertiary treatment. Normally all flow passes through the trickling filter works, after which it is further treated in the activated sludge works. During periods of high flow, excess flow that cannot be accommodated hydraulically in the trickling filter works, then bypasses this section and flows directly to the activated sludge works.
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In 2003, Drakenstein Municipality appointed Ninham Shand (now Aurecon) in association with Lyners to investigate and report on options for upgrading the existing WWTW to provide for nutrient removal, and in particular for phosphate removal (for a maximum ortho-phosphate level of 1 mg/L as PO4). Subsequent to this investigation, Drakenstein Municipality appointed Africon (now Aurecon) to compile a master plan which identified the preferred locations for future WWTW’s in the area. This investigation recommended that the existing Paarl WWTW be developed to a capacity of 35 Mℓ/d. The consulting engineers recommended the treatment of a blend of industrial humus tank effluent and settled and raw domestic sewage in a biological nutrient removal (BNR) activated sludge process. The process was achieved by converting the existing aerated lagoon to a BNR activated sludge system. Upgrading of the aerated lagoon was completed in March 2012.
A flow diagramme of the works is included in Annexure B.
3.2 Wellington WWTW 3.2.1 Catchment
The Wellington WWTW services the entire Wellington area, from the Newton- and Erf 8000 areas in the south to the Pentz Domestic area in the north as well as the Industrial Park Area in the west of Wellington. The WWTW is a Class C WWTW under the DWA classifications and currently has a capacity of 6Mℓ/d with a ADDWF of approximately 5.5Mℓ/d. Upgrading of this WWTW to a capacity of 16 Mℓ/d is currently underway. The WWTW is licensed by a water usage permit (No 918B). A layout of the Wellington WWTW catchment area is shown on drawing no 0828/C/003 in Annexure A. As with the Paarl WWTW, the receiving environment for the effluent from the Wellington WWTW is also the Berg River and the Wellington WWTW most also comply with the General Standard. In future the WWTW may also need to comply with the Special Standard.
3.2.2 Collection
Influent to the Wellington WWTW is from various Sewage Pumping Stations conveying sewage to the WWTW via rising mains. The various pumping stations in the Wellington area are shown in table 3.2 below.
Table 3.2 : Sewage Pumping Station within Wellington
Name of Pumping Station Pumping station to/into
Erf 8000 Newton Sewage Pumping Station
Newton Directly to the WWTW Inlet
Wellington Industries Directly to the WWTW Inlet *(1)
Pentz Street Industrial and Domestic Pumping Stations
Directly to the WWTW Inlet *(1)
Nywerheids Park Directly to the WWTW Inlet *(2)
Kromrivier Collector Sewers draining towards the Pentz Street Domestic Pumping Station
*(1)
These two pumping stations will be consolidated into one large pumping station (Pentz Street Sewage Pumping Station). Construction is estimated to be completed by June 2013.
*(2)
This pumping station was recently upgraded.
Currently the influent to the WWTW is not separately treated with respect to industrial- and domestic influent.
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Some of the pumping stations and rising mains such as the Pentz Street Domestic- and Industrial Pumping Stations are old or at capacity and require replacement or upgrading. However for the most part of the reticulation network is in good condition and have a remaining useful life similar to that of the Paarl. Some re-use of effluent is already implemented with the Wellington Golf Club receiving irrigation water from the works. This is on a relatively small scale and amount. Similarly to Paarl WWTW, it is envisioned that further re-use of effluent for irrigation or large industrial use must occur in future. This process is in the Planning Phase in conjunction with the Paarl WWTW.
3.2.3 Treatment
The Wellington WWTW combines the biological wastewater treatment systems of trickling filters and activated sludge. Raw wastewater (consisting of domestic sewage and industrial effluent) flows through an inlet works to two primary settling tanks and then to five trickling filters (biofilters) of which two are large biofilters supplemented by three smaller biofilters. The effluent from the biofilters is settled in two humus tanks and the settled water is then pumped to the activated sludge bioreactor and a secondary settling tank. The final effluent is chlorinated before receiving tertiary treatment in five maturation ponds in series. The effluent from the last maturation pond discharges to a natural stream which flows to the Berg River. Waste sludge is either treated in two anaerobic digesters and then in sludge drying beds, or in two sludge lagoons. The WWTW is in need of upgrading and extension of the treatment capacity. Aurecon in association with Lyners was appointed in 2010 to investigate options for the required upgrading and extensions. The project is currently (2013) in the in the Planning and Environmental Impact assessment Phase.
A flow diagramme of the works is included in Annexure B.
3.3 Pearl Valley WWTW 3.3.1 Catchment
The Pearl Valley WWTW services the Pearl Valley Golf Estate and the Val-de-Vie Developments to the south of Paarl. The WWTW is a Class D works under the DWA classifications and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.2Mℓ/d. This WWTW is licensed under a General Authorization (Ref 16/2/7/G100/A/8). A layout of the Pearl Valley WWTW catchment area is included in Annexure A drawing no 0828/C/001. Again the receiving environment for final effluent is the Berg River and the WWTW must also currently comply with the General Standard. It may also have to comply with the Special Standard in future.
3.3.2 Collection
Influent to this WWTW is domestic in nature and is conveyed to the WWTW via various Sewage Pumping Stations and Rising mains which are shown below in table 3.3.
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Table 3.3 : Sewage Pumping Stations in the Pearl Valley WWTW Catchment
Name of Pumping Station Pumping station to/into
Pearl Valley Directly to the WWTW Inlet
Val-de-Vie 3 Directly to the WWTW Inlet
Val-de-Vie 1,2,5 and 6- and the Guardhouse Pumping Stations
Collector sewers ultimately draining to Val-de-Vie 3 Pumping Station
These pumping stations and reticulation networks are relatively new and in good condition. 3.3.3 Treatment
The Pearl Valley WWTW’s consists of two nearly identical activated sludge modules. The first module (“old section”) was provided to treat the wastewater from the Pearl Valley Golf Estate, while the second module (“new section”) was added later to treat wastewater from the more recently established Val-de-Vie Development. Raw domestic sewage from the two private developments both enter the WWTWs in an inflow sump at the head of the works, from where it flows through a communal inlet works (hand raked screen; grit channels) to two activated sludge reactors. The reactors have been designed for biological nutrient removal and therefore include anoxic zones for denitrification. After the removal of the biomass (sludge) in the secondary settling tanks, the settled water is chlorinated and then polished in large maturation ponds before discharging to a natural water course leading to the Berg River. Waste sludge is disposed of in sludge drying beds. However, the system currently operates on a low MLSS, resulting in low waste sludge volumes to be disposed of. A mechanical sludge dewatering facility has also been provided at the WWTW, but to date this has not been used. A flow diagramme of the works is included in Annexure B.
3.4 Saron WWTW 3.4.1 Catchment
The Saron WWTW services the rural town of Saron north of Gouda. The WWTW is a Class E works under the DWA classification and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.8Mℓ/d. The WWTW is licensed by a General Authorization. A conditional assessment of the works was undertaken which recommended upgrading of various structures at the works which include construction of a new activated sludge reactor. The first phase of the upgrading project is currently in the construction phase with a second phase currently (2013) in the planning and EIA phase. A layout of the Saron WWTW catchment is included in drawing no 0828/C/006 in Annexure A. The receiving environment for this works is the Klein Berg River which ultimately drains to the Berg River. This works is also subject to the General Standard for effluent and may in future be subject to the Special Standard.
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3.4.2 Collection
Influent to this WWTW is domestic in nature and is conveyed to the WWTW from a Sewage Pumping Station which was recently upgraded. There are only two Sewage Pumping Stations in Saron which operate as shown in the table 3.4 below.
Tabel 3.4 : Sewage pumping station in Saron.
Name of Pumping Station Pumping station to/into
Saron 1 Collector sewer draining towards Pumping Station
Saron 2 Directly into the Saron WWTW inlet works*
* Recently upgraded
Although most of the reticulation network is old it is still in good condition. As stated above the Saron 2 Sewage Pumping Station and Rising main was recently upgraded. The conditional assessment of the works found that the structures in the WWTW with the exception of the Secondary Settling tank (Clarifier) and the chlorination channel were not in a good condition. Therefore refurbishment and upgrading of the works was proposed.
3.4.3 Treatment
The Saron WWTW is also an activated sludge treatment works, but unlike the Paarl and Wellington WWTW, it is a relatively small plant with open ponds converted to an activated sludge reactor, with an aerobic zone and an anoxic zone. Raw sewage from Saron enters the works via the inlet works (hand raked screen followed by grit channels) to the anoxic zone of the activated sludge reactor. It overflows to the aeration section (with floating aerators) and then to a secondary settling tank. Return activated sludge is recycled to the anoxic zone, and waste activated sludge discharged to the sludge drying beds from time to time (daily sludge wasting is recommended). The settled wastewater from the secondary settling tank is firstly disinfected through chlorination and then normally flows to a series of maturation ponds, located some distance from the works. These ponds have become redundant and are in the process of being upgraded. As stated above this WWTW must be upgraded and refurbished. A flow diagramme of the works is included in Annexure B.
3.5 Hermon WWTW 3.5.1 Catchment
The Hermon WWTW services the small rural town of Hermon which is only partly serviced by gravity sewers with a Sewage Pumping Station. The other section of Hermon has conservancy tanks which are emptied by tanker trucks at regular intervals and the sewage from the tankers is then taken to the WWTW. The WWTW is a Class E works, under the DWA classification and currently has a capacity of 0.3Mℓ/d and a ADDWF of approximately 0.1Mℓ/d. This plant operates under a General Authorization from DWA (Ref 16/2/7/G/10F). A layout of the Hermon WWTW catchment is shown on drawing no 0828/C/004 in Annexure A. As the works is and evaporation pond system there is no effluent outflow.
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3.5.2 Collection
As stated above Hermon is only partially serviced with gravity sewers draining to the Hermon Sewage Pumping Station which conveys sewage to the WWTW. The other section of Hermon has conservancy tanks which are emptied by tanker truck at regular intervals and taken to the WWTW.
It is envisioned that in future the conservancy tanks will be made redundant by the installation of gravity sewers and a new Sewage Pumping Station.
The existing reticulation system is relatively old but still in good condition.
3.5.3 Treatment
The treatment system for Hermon is an evaporation pond system, consisting of two large, unlined evaporation ponds. Provision has been made for using the pond overflow for irrigation purposes (an irrigation pump has been installed for this purpose), but currently both the ponds are empty due to evaporation and possible seepage.
A flow diagramme of the works is included in Annexure A.
3.6 Gouda WWTW 3.6.1 Catchment
The Gouda WWTW services the rural town of Gouda to the north of Hermon. The WWTW is a Class E works under the DWA classification currently having a capacity of 0.64Mℓ/d and a ADDWF of approximately 0.4Mℓ/d. The works is currently licensed by a water use permit (No 1331B). As this works is also an evaporation pond system there is no effluent outflow. A layout of the Gouda WWTW catchment is included in Annexure A drawing no 0828/C/005.
3.6.2 Collection
In the past Gouda was divided into two sections Gouda north (north of the R45) was serviced by gravity sewers draining towards the Gouda Sewage Pumping Station which conveyed sewage to the WWTW. The Gouda South section was serviced by conservancy tanks with tanker trucks removing sewage to the WWTW regularly. Construction of a gravity sewer reticulation network for the Gouda South section is currently underway. This new reticulation network will drain to the Gouda North network, onto the Gouda Sewage Pumping Station and ultimately the Gouda WWTW. The Gouda North reticulation network is relatively old but still in good condition. A new Gouda Sewage Pumping Station and reticulation network for Gouda South was recently completed and are at the start of their service life.
3.6.3 Treatment
The Gouda WWTW is a waste stabilisation pond system (evaporation ponds) consisting of two primary ponds, followed by four secondary oxidation ponds. The final effluent overflowing from the last pond is used as irrigation water on the rugby field in town. Upgrading and rehabilitation of the pond system was recently completed, which included upgrading of the pump station in the town. A flow diagramme of the works is included in Annexure B.
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4 HAZARD ASSESSMENT
In 2011 DWA promoted the use of a W2RAP to identify risks at WWTW’s in detail and to this end all
of Drakenstein Municipality’s WWTW were analysed and a W2RAP drafted.
The W
2RAP is based on a risk factor which is obtained as a product of the perceived probability of
occurrence and the significance or consequence. A risk matrix must be set up to classify risks as low, medium or high.
4.1 Risk Matrix used
As stated above the risk factor is calculated as follows :
Risk factor = Probability of occurrence X significance or consequence
Based on this equation the following risk matrix and factors were used as shown in Figure 4.1 below.
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Figure 4.1 : Risk Matrix used for Hazard Assessment
Min Risk
2 7 8 13 14 19 20 24 25 26 30
Max Risk
Low Risk 2 to 13 Medium Risk 14 to 25 High Risk 25 to 30
Probability Score (Probability of Occurrence)
Severity Score
(Consequence of failure)
1 Rare
(1 in 5 years)
2 Insignificant (No Impact)
2 Unlikely
(once per annum)
3 Minor
(Minor Impact to a large population)
3 Moderately Likely (once per month)
4 Moderate
(Moderate Impact to a large population)
4 Likely
(once per week)
5 Major
(Population exposed to significant illness)
5 Almost Certain
(Once a day or permanent feature)
6 Catastrophic
(Death expected from exposure)
Risk Matrix
Severity
Risk Matrix
Severity
2 3 4 5 6
2 3 4 5 6
Probability
1 2 3 4 5 6
Probability
1 2 3 4 5 6
2 4 6 8 10 12
2 4 6 8 10 12
3 6 9 12 15 18
3 6 9 12 15 18
4 8 12 16 20 24
4 8 12 16 20 24
5 10 15 20 25 30
5 10 15 20 25 30
Based on this risk matrix all risks are classified on their probability (score between 2 and 5) and severity (score between 2 and 6) and ranked as Low, Medium or High.
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This formed the basis for the Hazard Assessment undertaken for each WWTW below.
4.2 Hazard Analysis of works
A Hazard Assessment was undertaken for each WWTW taking into account, among others, the following.
- The catchment - Surface water - Ground water - Collector systems - Treatment - Other factors
The risk analysis further also differentiated between four district risk categories for each section of the works namely :
• Electrical failure (including motor failure, power failure, etc.)
• Mechanical failure (eg gearboxes, sluices, gate valves, pumps, etc.)
• Structural failure (eg structures needing replacement/refurbishment or upgrading)
• Process failure (non-compliance with DWA Standards, Operational monitoring etc.)
Risk scores were allocated based mostly on the effect on the receiving environment and the end user. The risk assessment is also only a high level risk assessment and may be elaborated on in future revisions of this document.
4.3 Paarl WWTW The full risk matrix for the Paarl WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.1 below.
Table 4.1 : Paarl WWTW : Medium to High Risk Items Item no
System Hazard/Risk Description
Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Process Failure
11 Domestic Pumping
Station Influent compliance Y 4 5 20 Medium
12 Domestic Pumping
Station Design Capacity Y 4 5 20 Medium
Mechanical Failure
20 Industrial Inlet
Works Hand Raked Screens Y 5 3 15 Medium
Process Failure
21 Industrial Inlet
Works Influent compliance Y 4 5 20 Medium
Process Failure
27 Flocculator Operational
Monitoring Y 4 4 16 Medium
Electrical Failure
28 Flocculator Power failure to
bridge Y 3 5 15 Medium
Structural Failure
30 Domestic
splitterbox Tower Y 3 5 15 Medium
Process Failure
33 Domestic PST's Operational
Monitoring Y 4 4 16 Medium
Structural Failure
38 Biofilters Old Biofilter walls Y 5 5 25 High
Process Failure
39 Biofilters Operational
Monitoring Y 4 4 16 Medium
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Item no
System Hazard/Risk Description
Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Process Failure
43 Humus Tanks Operational
Monitoring Y 4 4 16 Medium
Process Failure
60 Aerobic Zone Operational
Monitoring Y 4 5 20 Medium
Process Failure
66 Clarifier Operational
Monitoring Y 4 5 20 Medium
Structural Failure
67 New Clarifier Clarifier Structure too
low Y 4 4 16 Medium
Structural Failure
77 Tanks Dome structure on
Tanks Y 5 5 25 High
Structural Failure
78 Digester Structure of digester Y 5 5 25 High
General
80 Digester Deep Structure Y 5 5 25 High
General
81 Incinerators Incinerators very old Y 4 4 16 Medium
Process Failure
84 Maturation Ponds Operational
Monitoring Y 4 5 20 Medium
Electrical Failure
85 Chlorination Store
Room
Warning Lights
outside building Y 4 6 24 Medium
86 Chlorination Store
Room Dosing Electronics Y 4 6 24 Medium
Process Failure
89 Chlorination
Channel
Compliance
Monitoring Y 5 5 25 High
Electrical Failure
91 Transformer Transformers on site
(4 No) Y 5 5 25 High
92 Genset Switch Over Board Y 4 5 20 Medium
General
94 General Site Lighting Y 3 5 15 Medium
95 General Telemetry at works Y 5 4 20 Medium
The risks mainly include operational- and compliance monitoring, replacement or upgrading of structures and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table 4.2 below.
13
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Table 4.2 : Paarl WWTW : Risk Mitigation Measures for Medium to High Risks
Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls) Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment Recommended mitigation/
improvement plan
Process Failure
11 Domestic Pumping
Station
Influent
compliance 20 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 4 Low Operational monitoring is to occur to
operational monitoring alert level
Ensure monitoring occurs as
scheduled
12 Domestic Pumping
Station Design Capacity 20 Medium - 0 20 Medium
The existing Pumping Station has a
lower capacity than newly
constructed sewer
Investigate New pumping station
with higher capacity
Mechanical
Failure
20 Industrial Inlet
Works
Hand Raked
Screens 15 Medium
Permanent Cleaning of Screen
throughout the day 70 4.5 Low
Permanently posted staff clean hand
raked screen
Investigate installation of
mechanical screens in future
Process Failure
21 Industrial Inlet
Works
Influent
compliance 20 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 4 Low Operational monitoring is to occur to
operational monitoring alert level
Ensure monitoring occurs as
scheduled
Process Failure
27 Flocculator Operational
Monitoring 16 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 3.2 Low
Operational monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Electrical Failure
28 Flocculator Power failure to
bridge 15 Medium - 0 15 Medium
No power to the bridge at present
and process is being affected
Power to be provided to bridge
immediately
Structural
Failure
30 Domestic
splitterbox Tower 15 Medium - 0 15 Medium Tower must be investigated
Investigate structure of tower
and gratings
Process Failure
33 Domestic PST's Operational
Monitoring 16 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 3.2 Low Operational monitoring needed with
Actions as per Alert Level Follow Alert Level actions
Structural
Failure
38 Biofilters Old Biofilter
walls 25 High Structure strapping 10 22.5 Medium
currently strapping is used to
reinforce broken brickwork outer
walls
Refurbish walls as part of future
upgrade
Process Failure
39 Biofilters Operational
Monitoring 16 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 3.2 Low
Operational monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Process Failure
43 Humus Tanks Operational
Monitoring 16 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 3.2 Low
Operational monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Process Failure
60 Aerobic Zone Operational
Monitoring 20 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 4 Low Operational Monitoring to determine
sludge wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
Process Failure
66 Clarifier Operational
Monitoring 20 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 4 Low
Operational monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Structural
Failure
67 New Clarifier
Clarifier
Structure too
low
16 Medium - 0 16 Medium
The clarifier structure was
constructed low in the ground and
the possibility exists for someone to
fall into the clarifier as there is no
handrail around the clarifier
Construct handrail around
clarifier with apron
Structural
Failure
77 Tanks Dome structure
on Tanks 25 High
Signage, Gas traps and 24h
monitoring 80 5 Low
Inspection of the dome must
occur at regular interval as
determined by a structural
Engineer
Structural
Failure
78 Digester Structure of
digester 25 High
Signage, Gas traps and 24h
monitoring 80 5 Low
Inspection of the dome must
occur at regular interval as
determined by a structural
Engineer
General
80 Digester Deep Structure 25 High - 0 25 High No life buoy or safety ropes in a very
deep structure
Provide life buoys and safety
ropes for structure
General
81 Incinerators Incinerators
very old 16 Medium - 0 16 Medium
The incinerators are very old and
parts have become hard to source
Upgrade of the incinerators must
be investigated as part of future
upgrade
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls) Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment Recommended mitigation/
improvement plan
Process Failure
84 Maturation Ponds Operational
Monitoring 20 Medium
Operational Monitoring
through on site Mini Lab.,
weekly verification at Paarl
WWTW lab. and Monthly
Audit by Independent Lab.
(A.L. Abbott)
80 4 Low
Operational monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Electrical Failure
85 Chlorination Store
Room
Warning Lights
outside building 24 Medium
Warning lights checked daily,
with Reactive Maintenance
and Standby Generator on
Site
100 0 None Weekly inspection of
Component
86 Chlorination Store
Room
Dosing
Electronics 24 Medium
Reactive Maintenance and
Standby Generator on Site 80 4.8 Low
Weekly inspection of
Component
Process Failure
89 Chlorination
Channel
Compliance
Monitoring 25 High
24h Compliance Monitoring
with on site lab. Newly
refurbished
90 2.5 Low
Compliance Monitoring to occur to
alert levels with corrective actions as
per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is
followed
Electrical Failure
91 Transformer Transformers on
site (4 No) 25 High
Operation and Maintenance
from Drakenstein Electrical
Department
0 25 High
Drakenstein Electrical Department is
laboring under capacity constraints
and maintenance cannot always be
effected in time
Maintenance schedule for all
transformers which MUST be
adhered to and additional
staffing in the Electrical
Department
92 Genset Switch Over
Board 20 Medium - 0 20 Medium
The existing switch board is old and is
in need of upgrading with new
switchgear, etc.
Investigate upgrading of switch
board as part of future upgrade
of works
General
94 General Site Lighting 15 Medium Existing high mast lighting 50 7.5 Low Investigate additional high mast
lighting when required
95 General Telemetry at
works 20 Medium 0 20 Medium
Contractor appointed to upgrade
entire telemetry network
Monitor contractor performance
and telemetry performance after
commissioning
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If these mitigation measures are implemented the overall risk classification of the works may be regarded as low. 4.4 Pearl Valley WWTW
The full risk matrix for the Pearl Valley WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.3 below.
Table 4.3 : Pearl Valley WWTW : Medium to High Risk Items Item no
System Hazard/Risk Description
Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Electrical Failure
33 Chlorination Store
Room
Warning Lights
outside building Y 4 6 24 Medium
34 Chlorination Store
Room Dosing Electronics Y 4 6 24 Medium
Process Failure
38 Maturation Ponds Compliance
Monitoring Y 5 5 25 High
Electrical Failure
42 Pumping Station Power failure Y 5 4 20 Medium
43 Pumping Station Telemetry Y 4 5 20 Medium
Mechanical Failure
44 Sludge Drying
Beds Drainage Pump Y 4 4 16 Medium
General
45 General Security at works Y 4 6 24 Medium
46 General Office Facilities Y 5 6 30 High
The risks mainly include operational- and compliance monitoring, upgrading of structures and dangerous installations such as chlorination storage.
These risk are or can be mitigated by employing risk mitigation measures which are shown in table
4.4 below. Table 4.4 : Pearl Valley WWTW : Risk Mitigation Measures for Medium to High Risks
Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
Electrical
Failure
33 Chlorination
Store Room
Warning
Lights
outside
building
24 Medium
Reactive
Maintenance
and Standby
Generator on
Site
80 4.8 Low
An audit has
been
performed and
corrective
measures have
been
identified.
Weekly
inspection of
Component
34 Chlorination
Store Room
Dosing
Electronics 24 Medium
Reactive
Maintenance
and Standby
Generator on
Site
80 4.8 Low
An audit has
been
performed and
corrective
measures have
been
identified.
Weekly
inspection of
Component
Process
Failure
16
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
38 Maturation
Ponds
Compliance
Monitoring 25 High
Compliance
Monitoring
through on site
Mini Lab.,
weekly
verification at
Paarl WWTW
lab. and
Monthly Audit
by Independent
Lab. (A.L.
Abbott) and
Maturation
Pond
Maintenance
80 5 Low
Compliance
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level,
Algal problems
occurred in
retention pond
and retention
time was
reduced,
however
sediment
transport
remains
problematic
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed
Electrical
Failure
42 Pumping
Station
Power
failure 20 Medium
Standby
generator on
site & Overflow
pond
90 2 Low -
Pro-Active
Maintenance
Required &
servicing of
standby
generator
required
43 Pumping
Station Telemetry 20 Medium - 0 20 Medium
Contractor
appointed to
upgrade entire
telemetry
network
Monitor
contractor
performance
and telemetry
performance
after
commissioning
Mechanical
Failure
44 Sludge
Drying Beds
Drainage
Pump 16 Medium
Reactive
Maintenance 100 0 None
New Pump
Currently
sourced
Monitor
supplier
performance
and pump
performance
after
commissioning
General
45 General Security at
works 24 Medium - 0 24 Medium
No Security on
site
Provide security
guard and
facilities as part
of the future
upgrade
46 General Office
Facilities 30 High - 0 30 High
No office on
site. Non-
Compliance
with OSH Act
Provide office
facilities as part
of the future
upgrade
17
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If these mitigation measures are implemented the overall risk classification of the works may be regarded as low 4.5 Wellington WWTW The full risk matrix for the Wellington WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.5 below.
Table 4.5 : Wellington WWTW : Medium to High Risk Items Item no
System Hazard/Risk Description Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Electrical Failure
1 Pumping Station Power failure Y 5 5 25 High
Process Failure
2 Pumping Station Flow meter Y 3 5 15 Medium
Mechanical Failure
3 Pumping Station Screening of Sewage Y 4 5 20 Medium
General
6 Pumping Station No permanent
supervision Y 5 5 25 High
General
11 Pumping Station Security Y 5 5 25 High
General
12 Pumping Station Design Capacity
Exceedance Y 3 5 15 Medium
Mechanical Failure
14 Pumping Station Screening of Sewage Y 3 5 15 Medium
General
17 Pumping Station Security Y 5 5 25 High
18 Pumping Station Telemetry at pumping
Station Y 3 5 15 Medium
General
21 General Plant Design Capacity
Exceedance Y 5 5 25 High
Electrical Failure
22 Inlet Works Power failure Y 5 5 25 High
Process Failure
26 Inlet Works Influent compliance Y 4 5 20 Medium
Process Failure
31 PST's Operational Monitoring Y 4 4 16 Medium
Process Failure
37 Biofilters Operational Monitoring Y 4 4 16 Medium
Process Failure
43 Humus Tanks Operational Monitoring Y 4 4 16 Medium
Process Failure
55 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Process Failure
59 Clarifier Operational Monitoring Y 4 5 20 Medium
Electrical Failure
66 Chlorination Store
Room
Warning Lights outside
building Y 5 5 25 High
67 Chlorination Store
Room Dosing Electronics Y 5 5 25 High
Process Failure
70 Maturation Ponds Compliance Monitoring Y 5 5 25 High
General
71 Sludge Drying
Beds
Design Capacity
Exceedance Y 5 5 25 High
General
72 Digester No Gas Tank Y 4 5 20 Medium
General
73 Incinerator No incinerator on site
for screenings Y 4 5 20 Medium
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Item no
System Hazard/Risk Description Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
General
74 Personnel
Facilities Offices Y 4 5 20 Medium
75 General Telemetry at works Y 5 4 20 Medium
76 General Site Lighting Y 5 4 20 Medium
77 General Security Y 5 5 25 High
78 General Signage Y 5 5 25 High
The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table
4.6 below.
19
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Table 4.6 : Wellington WWTW : Risk Mitigation Measures for Medium to High Risks
Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration of any controls)
Existing controls Control
Effectiveness (%) Residual Risk
Score Comment Recommended mitigation/ improvement plan
Electrical Failure
1 Pumping Station Power failure 25 High - 0 25 High No Standby Generator on site, Urgently required as this is the closest
pumping station to the Berg River
Process Failure
2 Pumping Station Flow meter 15 Medium - 0 15 Medium Flow meter has not been commissioned
Mechanical Failure
3 Pumping Station Screening of Sewage 20 Medium Basket screen, inspected daily according to pumping station checklist 90 2 Low -
General
6 Pumping Station No permanent
supervision 25 High Daily inspections only 0 25 High Supervision required as pumping station is closest to Berg River
General
11 Pumping Station Security 25 High 3m high wall with barbed wire, fencing, security lights and Armed response 80 5 Low High vandalism rate at this pumping station forced extreme security
measures
General
12 Pumping Station Design Capacity
Exceedance 15 Medium - 0 15 Medium Capacity problems observed in past
Mechanical Failure
14 Pumping Station Screening of Sewage 15 Medium - 0 15 Medium Contract has been issued for provision of a mechanical screen
General
17 Pumping Station Security 25 High Broken fencing and Armed response 25 18.75 Medium High vandalism rate at this pumping station requires security measures
18 Pumping Station Telemetry at pumping
Station 15 Medium - 0 15 Medium
Telemetry required as pumping station is closest to Berg River,
Contractor appointed to upgrade entire telemetry network
General
21 General Plant Design Capacity
Exceedance 25 High 0 25 High
Upgrading of Plant Required, All flows pumped to WWTW therefor also
may need a balancing dam
Electrical Failure
22 Inlet Works Power failure 25 High No Standby Generator on site - 0 25 High No Standby Generator on Site
Process Failure
26 Inlet Works Influent compliance 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 4 Low Operational monitoring is to occur to operational monitoring alert level
Process Failure
31 PST's Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 3.2 Low Operational monitoring needed with Actions as per Alert Level
Process Failure
37 Biofilters Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low
Operational monitoring to occur to alert levels with corrective actions
as per Alert Level
Process Failure
43 Humus Tanks Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low
Operational monitoring to occur to alert levels with corrective actions
as per Alert Level
Process Failure
55 Aerobic Zone Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low Operational Monitoring to determine sludge wasting
Process Failure
59 Clarifier Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low
Operational monitoring to occur to alert levels with corrective actions
as per Alert Level
Electrical Failure
66 Chlorination Store
Room
Warning Lights outside
building 25 High
Reactive Maintenance and No Standby Generator on Site, Inspection completed
and Certificate for compliance obtained 90 2.5 Low A Standby Generator on site is imperative
67 Chlorination Store
Room Dosing Electronics 25 High
Reactive Maintenance and No Standby Generator on Site, Inspection completed
and Certificate for compliance obtained 90 2.5 Low A Standby Generator on site is imperative
Process Failure
70 Maturation Ponds Compliance Monitoring 25 High Compliance Monitoring through on site Mini Lab., weekly verification at Paarl
WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 5 Low
Compliance monitoring to occur to alert levels with corrective actions as
per Alert Level
General
71 Sludge Drying
Beds
Design Capacity
Exceedance 25 High - 0 25 High 2 Waste ponds, Large Sludge Volume coming into works.
General
72 Digester No Gas Tank 20 Medium - 0 20 Medium The plant has Gas Digesters but no gas tank. A waste to energy project
has been initiated which could utilize the gas
General
73 Incinerator No incinerator on site for
screenings 20 Medium Screenings conveyed to Paarl WWTW for Incineration 50 10 Low -
20
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration of any controls)
Existing controls Control
Effectiveness (%) Residual Risk
Score Comment Recommended mitigation/ improvement plan
General
74 Personnel
Facilities Offices 20 Medium Some office space provided with limited ablution facilities 10 18 Medium Existing facilities do not comply with OSH Act
75 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network
76 General Site Lighting 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient
77 General Security 25 High Existing Fence 25 18.75 Medium Contract for a new security fence has been issued and is underway
78 General Signage 25 High - 0 25 High Signage is required on site to comply with various statutory regulations
including the OSH Act
If these mitigation measures are implemented the overall risk classification of the works may be regarded as low
21
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4.6 Hermon WWTW
The full risk matrix for the Hermon WWTW is included in Annexure C.
The risk classified as Medium or High Risks are shown in table 4.7 below
Table 4.7 : Hermon WWTW : Medium to High Risk Items
Item no
System Hazard/Risk Description Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Process Failure
1 Inlet Influent compliance Y 4 5 20 Medium
Process Failure
6 Evaporation
pond 3
Operational
Monitoring Y 4 5 20 Medium
7 Evaporation
Ponds
Ground Water
Monitoring Wells Y 4 5 20 Medium
Structural Failure
8 Sump Structure Sump Structure Size Y 3 5 15 Medium
Mechanical Failure
9 Pumps Pump Failure Y 3 5 15 Medium
Electrical Failure
10 Pumps No Standby Power Y 5 5 25 High
General
11 General Telemetry at Pumping
Station Y 5 4 20 Medium
The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have any mechanical equipment. These risk are or can be mitigated by employing risk mitigation measures which are shown in table
4.8 below. Table 4.8 : Hermon WWTW : Risk Mitigation Measures for Medium to High Risks
Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
Process
Failure
1 Inlet Influent
compliance 20 Medium
Operational
monitoring
i.e.
Laboratory
testing
80 4 Low
Operational
monitoring is
to occur to
operational
monitoring
alert level
Ensure
monitoring
occurs as
scheduled
Process
Failure
6 Evaporation
pond 3
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
Investigate need
for Mini Lab. On
site
7 Evaporation
Ponds
Ground
Water
Monitoring
Wells
20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed
22
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
Structural
Failure
8 Sump
Structure
Sump
Structure
Size
15 Medium
Daily
inspection of
sump
according to
Pumping
Station
checklist
25 11.25 Low
Current sump
structure to
large and has
overflow
walls and no
Mechanical
screen.
Screenings
accumulate in
first chamber
and must be
manually
removed
Investigate
upgrade of
pumping station
and installation
of Mechanical
Screen
Mechanical
Failure
9 Pumps Pump
Failure 15 Medium
Reactive
maintenance
with 24h turn
around time
50 7.5 Low
Pumps may
experience
problems due
to screenings
clogging the
pumps
In the interm
continue daily
inspections and
Investigate
upgrade of
pumping station
and installation
of Mechanical
Screen in future
Electrical
Failure
10 Pumps No Standby
Power 25 High - 0 25 High
At the
moment no
Standby
Power at the
pumping
station
Investigate
supply of
standby power
generator at
pumping station
General
11 General
Telemetry
at Pumping
Station
20 Medium 0 20 Medium
Contractor
appointed to
upgrade
entire
telemetry
network
Monitor
contractor
performance
and telemetry
performance
after
commissioning
If these mitigation measures are implemented the overall risk classification of the works may be regarded as low
4.7 Saron WWTW The full risk matrix for the Saron WWTW is included in Annexure C.
The risk classified as Medium or High Risks are shown in table 4.9 below
Table 4.9 : Saron WWTW : Medium to High Risk Items
Item no
System Hazard/Risk Description
Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Electrical Failure
1 Inlet Works Power failure Y 5 5 25 High
Mechanical Failure
4 Inlet Works Hand Raked Screens Y 5 3 15 Medium
Process Failure
6 Inlet Works Influent compliance Y 4 5 20 Medium
7 Inlet Works Design Capacity N 4 5 20 Medium
Structural Failure
8 Inlet Works Inlet Works Structure Y 3 5 15 Medium
Electrical Failure
9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium
23
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Item no
System Hazard/Risk Description
Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Mechanical Failure
10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium
Structural Failure
11 Anaerobic Zone Zone Structure Y 4 4 16 Medium
Electrical Failure
12 Aerobic Zone Aerator Motors Y 4 4 16 Medium
Mechanical Failure
13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium
Process Failure
14 Aerobic Zone Operational
Monitoring Y 4 5 20 Medium
Structural Failure
17 Clarifier Clarifier Structure Y 3 5 15 Medium
Process Failure
18 Clarifier Operational
Monitoring Y 4 5 20 Medium
Mechanical Failure
20 Pumping Station Pumps Y 5 5 25 High
Electrical Failure
22 Chlorination Store
Room
Warning Lights
outside building Y 5 5 25 High
23 Chlorination Store
Room Dosing Electronics Y 5 5 25 High
Structural Failure
24 Chlorination Store
Room Store Room Structure Y 5 5 25 High
Structural Failure
25 Maturation Ponds Structures across river Y 4 4 16 Medium
Process Failure
26 Maturation Ponds Compliance
Monitoring Y 4 5 20 Medium
Structural Failure
27 Sludge Drying
Beds Bed Structures Y 4 6 24 Medium
Process Failure
28 Sludge Drying
Beds Filter Medium Y 5 3 15 Medium
General
29 General Telemetry at works Y 5 4 20 Medium
30 General Security Guard at
works Y 5 4 20 Medium
31 General Site Lighting Y 5 4 20 Medium
The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. As stated earlier in the document Saron WWTW required upgrading and it is therefore expected to identify so many risks These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.10 below.
24
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Table 4.10 : Saron WWTW : Risk Mitigation Measures for Medium to High Risks Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration of any controls)
Existing controls Control
Effectiveness (%) Residual Risk
Score Comment Recommended mitigation/ improvement plan
Electrical Failure
1 Inlet Works Power failure 25 High No Standby generator on site 0 25 High No Standby Generator on site Install Standby Generator as part of WWTW upgrade.
Contractor appointed and supply of generator imminent
Mechanical Failure
4 Inlet Works Hand Raked
Screens 15 Medium Permanent Cleaning of Screen throughout the day 70 4.5 Low
Permanently posted staff clean hand raked screen and a new
Mechanical screen will be provided at the Saron Sewage pumping
station in new contract
Monitor screenings amount after commissioning of
mechanical screen at Saron Sewage pumping station
Process Failure
6 Inlet Works Influent
compliance 20 Medium
Operational Monitoring through on site Mini Lab., weekly
verification at Paarl WWTW lab. and Monthly Audit by
Independent Lab. (A.L. Abbott)
90 2 Low Operational monitoring is to occur to operational monitoring alert
level Ensure monitoring occurs as scheduled
7 Inlet Works Design Capacity 20 Medium 0 20 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade
Structural Failure
8 Inlet Works Inlet Works
Structure 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade
Electrical Failure
9 Anaerobic Zone Mixer Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and
Servicing
Mechanical Failure
10 Anaerobic Zone Mixer Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and
Servicing
Structural Failure
11 Anaerobic Zone Zone Structure 16 Medium 0 16 Medium New Reactor must be constructed as part of WWTW upgrade Construct new Reactor as part of WWTW upgrade
Electrical Failure
12 Aerobic Zone Aerator Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time
Hour Logging, Pro-Active Maintenance and Servicing or
possible standby Aerator. Also investigate timer for low
flow periods
Mechanical Failure
13 Aerobic Zone Aerator Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time
Hour Logging, Pro-Active Maintenance and Servicing or
possible standby Aerator. Also investigate timer for low
flow periods
Process Failure
14 Aerobic Zone Operational
Monitoring 20 Medium
Operational Monitoring through on site Mini Lab., weekly
verification at Paarl WWTW lab. and Monthly Audit by
Independent Lab. (A.L. Abbott)
90 2 Low Operational Monitoring to determine sludge wasting Operational Monitoring as scheduled with process
adjustments at alert levels as necessary
Structural Failure
17 Clarifier Clarifier Structure 15 Medium Inspection of Structure 0 15 Medium Inspection must occur during cleaning, Cracks observed on outside. Inspect structure during cleaning, perform structural
investigation with report
Process Failure
18 Clarifier Operational
Monitoring 20 Medium
Operational Monitoring through on site Mini Lab., weekly
verification at Paarl WWTW lab. and Monthly Audit by
Independent Lab. (A.L. Abbott)
90 2 Low Operational monitoring to occur to alert levels with corrective
actions as per Alert Level
Ensure Monitoring occurs as scheduled and incident
management protocol is followed
Mechanical Failure
20 Pumping Station Pumps 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump Investigate installation of standby pump in sum as part of
future upgrade
Electrical Failure
22 Chlorination
Store Room
Warning Lights
outside building 25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low
Entire system will be replaced with Chlorine tablet system until
future upgrade is completed
Coordinate a new disinfection system with future upgrade
of works
23 Chlorination
Store Room Dosing Electronics 25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low
Entire system will be replaced with Chlorine tablet system until
future upgrade is completed
Coordinate a new disinfection system with future upgrade
of works
Structural Failure
24 Chlorination
Store Room
Store Room
Structure 25 High Inspection of Structure 50 12.5 Low
Entire system will be replaced with Chlorine tablet system until
future upgrade is completed
Coordinate a new disinfection system with future upgrade
of works
Structural Failure
25 Maturation
Ponds
Structures across
river 16 Medium 0 16 Medium
Structure across river may have leakages in crossing, relining of 1st
pond currently (2012) underway
Construct new Maturation ponds closer to the WWTW as
part of upgrading of WWTW
Process Failure
26 Maturation
Ponds
Compliance
Monitoring 20 Medium
Operational Monitoring through on site Mini Lab., weekly
verification at Paarl WWTW lab. and Monthly Audit by
Independent Lab. (A.L. Abbott)
90 2 Low Compliance monitoring to occur to alert levels with corrective
actions as per Alert Level
Ensure Monitoring occurs as scheduled and incident
management protocol is followed
Structural Failure
27 Sludge Drying
Beds Bed Structures 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished
Process Failure
28 Sludge Drying
Beds Filter Medium 15 Medium 0 15 Medium
Water does not filter through quick enough, Contractor appointed
to refurbish the beds
All beds to be refurbished, monitor speed of water
filtration after refurbishments are complete
General
29 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network Monitor contractor performance and telemetry
performance after commissioning
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration of any controls)
Existing controls Control
Effectiveness (%) Residual Risk
Score Comment Recommended mitigation/ improvement plan
30 General Security Guard at
works 20 Medium 0 20 Medium No security guard at the works.
Provide security guard and facilities as part of the future
upgrade
31 General Site Lighting 20 Medium 0 20 Medium Minimal site lighting Additional site lighting must be provided as part of future
upgrade
If these mitigation measures are implemented the overall risk classification of the works may be regarded as Medium and therefore motivates the upgrades currently in progress.
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4.8 Gouda WWTW
The full risk matrix for the Gouda WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.11 below
Table 4.11 : Gouda WWTW : Medium to High Risk Items Item no
System Hazard/Risk Description Could this issue result in a risk?
Likelihood Consequence Inherent Risk Score (before
consideration of any controls)
Electrical Failure
2 Pumping
Station Standby power Y 5 5 25 High
Process Failure
4 Inlet Influent compliance Y 4 5 20 Medium
Mechanical Failure
5 Inlet Hand Raked Screens Y 5 3 15 Medium
Process Failure
1 Inlet Spetic tank influent
compliance Y 4 5 20 Medium
Process Failure
10 Primary Pond 1 Operational
Monitoring Y 4 5 20 Medium
11 Primary Pond 2 Operational
Monitoring Y 4 5 20 Medium
12 Secondary
Pond 3
Operational
Monitoring Y 4 5 20 Medium
13 Secondary
Pond 4
Operational
Monitoring Y 4 5 20 Medium
14 Secondary
Pond 5
Operational
Monitoring Y 4 5 20 Medium
15 Secondary
Pond 6 Compliance Monitoring Y 5 5 25 High
16 Evaporation
Ponds
Ground Water
Monitoring Wells Y 4 5 20 Medium
General
17 General Telemetry at works Y 5 4 20 Medium
18 General Security Guard at
works Y 5 4 20 Medium
19 General Site Lighting Y 5 4 20 Medium
The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have much mechanical equipment.
These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.12 below.
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Table 4.12 : Gouda WWTW : Risk Mitigation Measures for Medium to High Risks
Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
Electrical
Failure
2 Pumping
Station
Standby
power 25 High - 0 25 High
No Standby
Power
generator
available on
site
A standby power
generator must
be provided for
the pumping
station
Process
Failure
4 Inlet Influent
compliance 20 Medium
Operational
monitoring
through
weekly testing
as there is no
effluent
outflow from
this
evaporation
pond system
90 2 Low
Operational
monitoring is
to occur to
operational
monitoring
alert level
Ensure
monitoring
occurs as
scheduled
Mechanical
Failure
5 Inlet Hand Raked
Screens 15 Medium
Permanent
Cleaning of
Screen
throughout
the day
90 1.5 None
Permanently
posted staff
clean hand
raked screen,
however low
screenings
volume due to
mechnical
screen at
Gouda Sewage
Pumping
Station
Clean Screen
Daily
Process
Failure
1 Inlet
Spetic tank
influent
compliance
20 Medium - 0 20 Medium
No monitoring
of farms septic
tank loadings
(e.g. COD, etc.)
Sampling of farm
septic tanks
inffluent must be
performed to
gauge impact on
process
Process
Failure
10 Primary
Pond 1
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
11 Primary
Pond 2
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
12 Secondary
Pond 3
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
13 Secondary
Pond 4
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
14 Secondary
Pond 5
Operational
Monitoring 20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
15 Secondary
Pond 6
Compliance
Monitoring 25 High
Compliance
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2.5 Low
Compliance
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
16 Evaporation
Ponds
Ground
Water
Monitoring
Wells
20 Medium
Operational
Monitoring
weekly
sampling with
monthly
audits by
independent
lab. (A.L.
Abbott)
90 2 Low
Operational
monitoring to
occur to alert
levels with
corrective
actions as per
Alert Level
Ensure
Monitoring
occurs as
scheduled and
incident
management
protocol is
followed,
investigate
feasibility of Mini
lab. On site
General
17 General Telemetry
at works 20 Medium 0 20 Medium
Contractor
appointed to
upgrade entire
telemetry
network
Monitor
contractor
performance and
telemetry
performance
after
commissioning
18 General
Security
Guard at
works
20 Medium 0 20 Medium
No security
guard at the
works.
Provide security
guard and
facilities as part
of the future
upgrade
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Item no
System Hazard/Risk Description
Inherent Risk Score (before consideration
of any controls)
Existing controls
Control Effectiveness
(%)
Residual Risk Score
Comment
Recommended mitigation/
improvement plan
19 General Site Lighting 20 Medium 0 20 Medium Minimal site
lighting
Additional site
lighting must be
provided as part
of future
upgrade
If these mitigation measures are implemented the overall risk classification of the works may be regarded as low
5 CONTROL MEASUREMENTS
The municipality conducts operational control of the WWTW’s according to a comprehensive operational monitoring program, which meets the minimum requirement of DWA as stipulated in the Green Drop certification criteria. Sampling is done on a frequent basis by the treatment plant personnel at the various WWTW’s, and analysed in a well-equipped laboratory situated at the Paarl WWTW. The operational monitoring programme of Drakenstein Municipality is summarised in the table 5.1 below:
Table 5.1 : Drakenstein Municipality’s Operational Monitoring Programme
Industries (Monitoring Intervals) WWTWs (Monitoring Intervals)
Paarl Weekly Paarl Weekly, 24 hrs Tuesday to Wednesday. Final
effluent weekly
Wellington Two Weekly Wellington
Two Weekly, 24 hrs Wednesday to Thursday. Final effluent weekly
Smaller WWTW’s Final effluent twice per week
Industries (Analysis) WWTW’s (Analysis)
pH, Electrical Conductivity, COD, Phosphates See Table 5.2
WWTW’s Sampling Points
Paarl
Industrial raw inlet, Industrial raw settled, Domestic raw inlet, Domestic raw settled, Biofilters (5 sets) inlet and outlet, Humus settling tanks (5) outlet, Combined humus tank effluent (to activated sludge), Clarifiers (2) outlet, Maturation (aeration) pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS
Wellington Raw inlet, Raw inlet settled (3 Primary settling tanks), Biofilters (5 sets) inlet and outlet, Humus settling tanks (2) outlet, Clarifiers (2) outlet, Retention pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS
Pearl Valley Raw inlet, Clarifier, Final effluent, Activated sludge MLSS
Saron Raw inlet, Clarifier, Final effluent, Activated sludge MLSS
Gouda Oxidation ponds outlets (7)
Hermon Raw inlet, Final effluent
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Table 5.2: Drakenstein Municipality’s Sample Analysis Details
WWTW Sampling point Frequency of
sampling Analyses performed on the samples
Paarl
Industrial raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb
Industrial raw settled Weekly COD, pH, EC, ammonia, phosphate
Domestic raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb
Domestic raw settled Weekly COD, pH, EC, ammonia, phosphate
Biofilters (5 sets) inlet and outlet)
Weekly COD, pH, EC
Humus settling tanks (5) outlet Weekly COD, pH, EC
Combined humus tank effluent (to activated sludge)
Weekly COD, pH, EC
Clarifiers (2) outlet Weekly COD, pH, EC
Maturation (aeration) pond Weekly COD, pH, EC, dissolved oxygen, temp, ammonia, phosphate
Final effluent to Berg river (chlorinated)
Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl
-,
Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2
Activated sludge MLSS Daily suspended solids
Wellington
Raw inlet Daily COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb
Raw inlet settled
(3 primary settling tanks) Weekly COD, pH, EC, tot.alk., ammonia, phosphate
Biofilters (5 sets) inlet and outlet
Weekly COD, pH, EC
Humus Settling tanks (2) outlet Weekly COD, pH, EC
Clarifiers (2) outlet Daily COD, pH, EC
Retention pond Weekly COD, pH, EC
Final effluent to Berg river (chlorinated)
Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl
-,
Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2
Activated sludge MLSS Daily suspended solids
Pearl Valley
Raw inlet 2/week COD, pH, EC, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb
Clarifier 2/week COD, pH, EC
Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl-,
Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2
Activated sludge MLSS 2/week suspended solids
Saron
Raw inlet 2/week COD, pH, EC, tot.alk., ammonia, phosphate
Clarifier 2/week COD, pH, EC
Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl-,
Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2
Activated sludge MLSS 2/week suspended solids
Gouda
Oxidation pond 1 raw 2/week COD, pH, EC, ammonia, phosphate, tot.alk
Oxidation pond 2 raw Weekly COD, pH, EC, ammonia, phosphate, tot.alk
Oxidation pond 3 outlet Weekly COD, pH, EC
Oxidation pond 4 outlet Weekly COD, pH, EC
Oxidation pond 5 outlet Weekly COD, pH, EC
Oxidation pond 6 outlet Weekly COD, pH, EC
Oxidation pond 7 outlet 2/week COD, pH, EC
Oxidation pond 8 (final effluent) COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.
Hermon Raw inlet 2/week COD, pH, EC, ammonia, phosphate
Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.
The sampling (location; frequency) performed at the various treatment plants is in accordance with
the minimum requirements of the Green Drop programme of DWA.
The critical monitoring points for all the Activated Sludge WWTW’s is the discharge points from where problems in the process can be identified through the other monitoring points.
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6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL
The Drakenstein Municipality Wastewater Section has implemented an incident response protocol, in which certain reactive procedures are followed when an incident occurs (normally when a malfunction of the treatment processes occur due to power failures, faulty equipment, adverse weather conditions, human error, etc). There are two levels of incident management, firstly when a final effluent is discharged that does not meet the requirements of the Water Act, and secondly when an event takes place causing a major pollution event for which emergency response is required. Currently, these requirements are the General Standard for the Paarl, Wellington-, Pearl Valley- and Saron WWTW, and Irrigation Standards for the Gouda and Hermon Pond Systems. After the recent upgrading of the Paarl WWTW and upgrading of the Wellington WWTW in the near future, both of these plants will have to comply with the Special Standard for discharging into the Berg River. The Pearl Valley WWTW will also be required to meet the Special Standard requirements. A set of Compliance Alert Levels, corresponding to the requirements of the General Standard (at present), has been drawn up as part of a Wastewater Incident Management Protocol for Drakenstein Municipality, and is shown in the table 6.1 below. Table 6.1 : Compliance Alert Levels
Table 6.1: WWTW’s Compliance Alert Levels
Compliance Monitoring Sample
Alert Levels requiring action Response Protocol
Paarl WWTW
Final Effluent
COD > 75 mg/L
TSS > 25 mg/L
5.5 > pH > 9.5
EC > 150 mS/m
Ammonia > 6 mg/L as N
Nitrate > 15 mg/L as N
Ortho- P > 10 mg/L as P
Total Cl2 < 0.3 mg/L
E. Coli > 100 #/100 mL
Temp > 300 C
Cd > 0.005 mg/L
Cr > 0.05 mg/L
Cu > 0.01 mg/L
Zn > 0.1 mg/L
Pb > 0.01mg/L
Laboratory personnel to notify:
- Mr. Frans van Rooyen
- Mr. Cecil Paulse
- Mr. Cedric Morkel
Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed
Wellington WWTW
Final Effluent
COD > 75 mg/L
TSS > 25 mg/L
5.5 > pH > 9.5
EC > 150 mS/m
Ammonia > 6 mg/L as N
Nitrate > 15 mg/L as N
Ortho- P > 10 mg/L as P
Total Cl2 < 0.3 mg/L
E. Coli > 100 #/100 mL
Temp > 300 C
Cd > 0.005 mg/L
Cr > 0.05 mg/L
Cu > 0.01 mg/L
Zn > 0.1 mg/L
Pb > 0.01mg/L
Laboratory personnel to notify:
- Mr. Adam van Wyk
- Mr. Cecil Paulse
- Mr. Cedric Morkel
Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed
Pearl Valley WWTW
Final Effluent
COD > 75 mg/L
TSS > 25 mg/L
5.5 > pH > 9.5
EC > 150 mS/m
Ammonia > 6 mg/L as N
Nitrate > 15 mg/L as N
Ortho- P > 10 mg/L as
Total Cl2 < 0.3 mg/L
E. Coli > 100 #/100 mL
Temp > 300 C
Cd > 0.005 mg/L
Cr > 0.05 mg/L
Cu > 0.01 mg/L
Zn > 0.1 mg/L
Pb > 0.01mg/L
Laboratory personnel to notify:
- Mr. Shane Gardner
- Mr. Cecil Paulse
- Mr. Cedric Morkel
Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed
Saron WWTW
Final Effluent
COD > 75 mg/L
TSS > 25 mg/L
5.5 > pH > 9.5
EC > 150 mS/m
Ammonia > 6 mg/L as N
Nitrate > 15 mg/L as N
Ortho- P > 10 mg/L as
Total Cl2 < 0.3 mg/L
E. Coli > 100 #/100 mL
Temp > 300 C
Cd > 0.005 mg/L
Cr > 0.05 mg/L
Cu > 0.01 mg/L
Zn > 0.1 mg/L
Pb > 0.01mg/L
Laboratory personnel to notify:
- Ms. Tanya Simons
- Mr. Cecil Paulse
- Mr. Cedric Morkel
Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed
When the Compliance Alert Levels are exceeded, the actions stipulated in the Wastewater Incident Management Protocol of the municipality are followed. The Protocol is included in Annexure D.
For serious incidents or emergency situations, additional actions and notifications are required, including notification of DWA and the media/public. The protocol to be followed in these situations is included in the Wastewater Incident Management Protocol.
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6.1 Operational Alert Levels
For continuously improving the performance of the various WWTW’s, a set of operational alert levels has also been drawn up and followed by the operating personnel. The Operational Alert Levels are tabled below.
Table 6.2.1: WWTW’s Operational Alert Levels
ALL ACTIVATED SLUDGE WASTEWATER TREATMENT WORKS
(Paarl / Wellington / Pearl Valley / Saron)
Operational Samples Alert Levels Actions to be taken
Raw inlet
COD > 1000 mg/L
Ammonia > 100 mg/L as N
5.5 > pH > 9.5
EC > 150 mS/m
Settl. solids > 20 mL/L
Cd > 0.005 mg/L
Cr > 0.05 mg/L
Cu > 0.01 mg/L
Zn > 0.1 mg/L
Pb > 0.01 mg/L
• Check for possible illegal industrial effluent discharge
• Do more frequent measurements of DO levels, pH and MLSS in the activated sludge reactor
Raw inlet settled COD > 400 mg/L
• Check operation of PST (faulty scrapers; blockages)
• Check for oils and fats on the water surface
Activated sludge reactor
DO < 0.5 mg/L • Increase aeration capacity or cycles
MLSS < 2000 mg/L • Reduce discharge of WAS and allow MLSS –
levels to increase to 4000 mg/L
MLSS > 6000 mg/L • Gradually waste more sludge on a daily basis
to reduce the MLSS to 4000 mg/L
pH < 7.0
• Add lime to the inlet works to maintain the pH in the reactor at 7.0 or slightly above
Secondary settling tanks
COD > 75 mg/L
• Check for sludge carry – over from secondary settling tanks
• Check RAS recycle rates
• Check for bulking sludge
• Check for rising sludge
Take actions to rectify as appropriate
6.2 Verification of functioning of W2RAP
It is imperative that the functioning of the W2RAP can be monitored. If the W
2RAP is functioning
correctly there should be a decrease in risk and consequently better Wastewater treatment. There are various legislative requirements which will monitor the functioning of the W
2RAP indirectly,
such as the Green Drop Certification process and the RPMS system implemented by DWA. A well functioning W
2RAP will show improved scores in these processes.
Internal monitoring will also show improvement from well functioning W
2RAP. Comparisons of
internal monitoring results such as final effluent compliance over time will provide an indication of W
2RAP effectiveness.
Furthermore the W
2RAP is to be used inter alia with other Municipal Systems such as the Asset
Management Plan and the Operational and Maintenance Plans and the risk mitigation measures employed or identified in the W
2RAP must be aligned with these plans.
As stated above the W
2RAP must be reviewed at least once a year. A well functioning W
2RAP will
show a reduction in risk, year on year, due to implementation of mitigation measures.
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7 SUPPORT PROGRAMMES
Drakenstein Municipality provides various training projects and supporting programmes to educate their staff.
7.1 Process Controller Training Provided
On request of the Engineer: Waste Services (Mr R Brown), an on-site short course in wastewater treatment was presented to the process controllers and plant managers of the Drakenstein Municipality Wastewater Section by Water Training Africa in association with Seboka Manyabolo Management Solutions. The three-day course was presented on 3-5 May 2010 at the Training Centre of the Drakenstein Municipality and included practical training on site at the Paarl, Wellington, Pearl Valley and Saron wastewater treatment plants.
The course covered all aspects of municipal wastewater treatment, with an emphasis on practical aspects, and monitoring requirements. Evaluation of the candidates was done by means of a written-test, and certificates were presented to the course attendees on completion of the course.
7.2 Supervisors Forum
Drakenstein Municipality in conjunction with the University of Stellenbosch have partnered with other Municipalities within the Western Cape to be part of a WWTW Supervisors forum, where supervisors come together for training events and knowledge sharing.
Through this initiative valuable knowledge and problems solving skills are imparted on WWTW Supervisors. This type of support will provide valuable knowledge for incident situations. 7.3 Career Pathing
Professor Lagardien of the Cape Peninsula University of Technology has been approached to perform a Human Capital Development Audit which will inform the Municipality on career pathing and training priorities for its staff. Through this initiative risks associated with staffing problems can be addressed.
7.4 Consultant Advisors
The Municipality currently also employs several consultants, such as AL Abbott Laboratories and Integral Laboratories, to assist the Municipality with process audits.
These consultants form an integral part of the monitoring and verification processes which unfortunately, the Municipality does not always have the capacity to perform at the moment. 8 INCIDENT MANAGEMENT PLAN
Drakenstein Municipality has implemented an Incident Management Protocol (Annexure D) for all of their WWTW. The protocol differentiates between three alert levels based on the severity of the incident. These alert levels are shown in figure 8.1 below.
34
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Figure 8.1 Alert Levels and Reporting Implementation of these alert levels and the actions will occur as shown in the flowchart in figure 8.2 below.
Alert Level III:
Definite risk to health
or possible death
Inform : All stated for alert level two and Disaster and Emergency Management, Head of Department : Civil Engineering Services, Executive Director : Infrastructure and Planning, Municipal Manager, DWA, General PublicAction : As per protocol
Alert Level II:
Potential risk to health
Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor, District Supervisor, Head of Waste Services
Action : As per protocol
Alert Level I :
No significant risk to health
Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor
Action : As per protocol
35
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Figure 8.2 Flow Chart of Incident Protocol
Incident
Senior Chemist or Process Controller : Report incident to Plant Supervisor
Plant Supervisor : Can Problem be Solved ?
Yes
Plant Supervisor to implement corrective action and report to District Supervisor
No
District Supervisor : Can Problem be Solved ?
Yes
District Supervisor to implement Incident Management Protocol and report to Head of Waste Services
No
Head of Waste Services: Can Problem be Solved ?
Yes
Head of Waste Services to implement Incident Management Protocol and report to Head of Department : Civil Engineering Services
No
Head of Waste Services to report and provide ongoing updates to :
Implement Incident Management Protocol
Disaster Management and Environmental Management
Head of Department : Civil Engineering Services
Executive Director : Infrastructure and Planning
Municipal Manager
Press, Public and DWA
Alert Level I
Alert Level II
Alert Level III
36
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9 CONCLUSIONS
The Hazard- or Risk Assessments of the various works show that Drakenstein Municipality have or are implementing various methods which mitigate their risks in terms of wastewater treatment. Saron WWTW is the highest risk and is therefore currently upgraded. The next phase of the upgrade also needs to be implemented as a matter of urgency. Initiatives include various training programmes for staff as well as cooperative governance. Furthermore the municipality also has implemented various management plans which include Incident Management Protocols, Asset Management and Operation and Maintenance Plans. Various risks have been identified for each works and mitigation measures have been proposed.
10 RECOMMENDATIONS 10.1 Risks to be addressed
The various high to medium risk items which must be addressed are shown in Annexure E along with the proposed mitigation measures. The most urgent risks are those associated with the Saron- and Wellington WWTW’s of which emergency funding for Saron WWTW is being applied for and the Wellington WWTW upgrading is in the planning and EIA phase.
10.2 Way forward
Priority must be given to the high risk items at each WWTW and allocations must be made through either staffing, operation and maintenance- or capital project budgets. An internal W²RAP workshop with all WWTW staff must be conducted to familiarize them with the W²RAP and the principle of risk management A yearly review of the W²RAP must be scheduled. It is proposed that the W²RAP must be updated in February every year.
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ANNEXURE A :
CATCHMENTS
U:\Werke\0800\0828 - Drakenstein W2RAP\Rep\W2RAP revB 2013\0828 W2RAP Report Rev B Feb 2013.docx
ANNEXURE B :
FLOW DIAGRAMMES
U:\Werke\0800\0828 - Drakenstein W2RAP\Rep\W2RAP revB 2013\0828 W2RAP Report Rev B Feb 2013.docx
ANNEXURE C :
DRAKENSTEIN MUNICIPALITY :
WWTW RISK ASSESSMENT
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Pumping Station Pumps Y 2 2 4 Low2 Standby 1 Duty pumps , Daily pumping
Station inspection with checklist50 2 Low Reactive maintenance C Morkel Ongoing
2 Pumping Station Flow Meter Y 2 2 4 LowDaily pumping Station inspection with
checklist50 2 Low Reactive maintenance C Morkel Ongoing
3 Pumping Station Power Failure Y 2 2 4 Low Standby generator on site 90 0.4 NoneProactive maintenance and
servicing required for GeneratorC Morkel Ongoing
Mechanical Failure
4 Pumping Station Mechanical Screen Y 2 2 4 LowDaily pumping Station inspection with
checklist50 2 Low Reactive maintenance C Morkel Ongoing
5 Pumping Station Washer Compactor Y 1 2 2 LowDaily pumping Station inspection with
checklist50 1 None Reactive maintenance C Morkel Ongoing
Structural Failure
6 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 NoneInspection of structure must occur
during cleaningC Morkel Ongoing
Electrical Failure
7 Domestic Pumping Station Failure of Pump MC Y 3 3 9 LowStandby Pumps installed & Standby
Generator- 100 0 None
Only becomes risk if O&M not applied or applied
lateMust follow O&M procedure C Morkel Ongoing
Mechanical Failure
8 Domestic Pumping Station Pump Failure Y 3 4 12 Low Standby Pumps installed - 50 6 Low
Long turnaround on pump repairs may cause risk
and unscreened sewage is pumped which may lead
to pump blockage
Time restriction on pump repair
for suppliers, installation of
mechanical screens must be
investigated during future upgrade
C Morkel & R Brown & Consultants Ongoing
9 Domestic Pumping Station Valve or sluice gate failure N 1 3 3 Low Gasket for all three pumps including standby - 100 0 None
Structural Failure
10 Domestic Pumping Station Pump station sump Y 1 5 5 LowPhysical inspection of the sump during
scheduled cleaning- 50 2.5 Low Visual inspection may not reveal all problems
Visual inspection of sump must be
recordedC Morkel Ongoing
Process Failure
11 Domestic Pumping Station Influent compliance Y 4 5 20 Medium Operational monitoring i.e Laboratory testing - 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
12 Domestic Pumping Station Design Capacity Y 4 5 20 Medium - - 0 20 MediumThe existing Pumping Station has a lower capacity
than newly constructed sewer
Investigate New pumping station
with higher capacityR Brown & Consultants 2016
Electrical Failure
13 Domestic Inlet Works Power failure Y 3 4 12 Low Standby generator on site - 100 0 None
14 Domestic Inlet Works Motor failure N 2 3 6 Low 2No so will be able to function with 1 100 0 None Backup grit removal mechanical screen and pumps
Mechanical Failure
15 Domestic Inlet Works Mechanical screen N 1 2 2 Low Standby screen available 100 0 None
16 Domestic Inlet Works Grit removal (Vortex) N 1 2 2 Low 2No so will be able to function with 1 100 0 None
17 Domestic Inlet Works Pumps N 2 3 6 Low Standby pump available 100 0 None
Structural Failure
18 Domestic Inlet Works Inlet works N 1 2 2 Low Structure is new 100 0 NoneVisual inspection with timing
determined by Asset RegisterR Brown TBC
Mechanical Failure
19 Industrial Inlet Works Hand Sluices Y 1 4 4 LowInspection of Sluices and Standby Stream
through daily inspections as per checklist80 0.8 None
Inspect and test permanently
closed sluices at least once a yearC Morkel Yearly
20 Industrial Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day70 4.5 Low Permanently posted staff clean hand raked screen
Investigate installation of
mechanical screens in futureC Morkel & R Brown & Consultants 2016
Process Failure
21 Industrial Inlet Works Influent compliance Y 4 5 20 Medium Operational monitoring i.e Laboratory testing - 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
Structural Failure
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Pa
arl
WW
TW
Mb
ek
we
ni
Se
wa
ge
Pu
mp
ing
Sta
tio
nD
om
est
ic P
um
pin
g S
tati
on
Inle
t W
ork
s
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
22 Industrial Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly
Electrical Failure
23 Industrial Pumping Station Power failure Y 3 4 12 Low Standby generator on site - 100 0 None
24 Industrial Pumping Station Pump Motor's and MCC Y 2 4 8 LowReactive Maintenance, Standby Generator
and Standby Pump90 0.8 None
Pro-Active Maintenance and
ServicingC Morkel Ongoing
Mechanical Failure
25 Industrial Pumping Station Pumps Y 2 4 8 Low Reactive Maintenance Standby Pump 80 1.6 NonePro-Active Maintenance and
ServicingC Morkel Ongoing
Structural Failure
26 Flocculator Flocculator Structure Y 3 3 9 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly
Process Failure
27 Flocculator Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory
testing80 3.2 Low
Operational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Electrical Failure
28 Flocculator Power failure to bridge Y 3 5 15 Medium - 0 15 MediumNo power to the bridge at present and process is
being affected
Power to be provided to bridge
immediatelyC Morkel & R Brown End 2012
Mechanical Failure
29 Domestic splitterbox Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year C Morkel Yearly
Structural Failure
30 Domestic splitterbox Tower Y 3 5 15 Medium - - 0 15 Medium Tower must be investigatedInvestigate structure of tower and
gratingsR Brown/Sub-consultants 2016
Electrical Failure
31 Domestic PST's Motor for Scum plate bridge Y 2 3 6 Low Operation & Maintenance - 50 3 Low Re-active maintenance at the moment Pro-active maintenanceR Brown
C Morkel2015
Structural Failure
32 Domestic PST's Structure Y 1 5 5 Low Inspection of structure - 50 2.5 LowOne of the PST's recently inspected and needed
refurbishment
Continual inspection during
mandatory shutdownC Morkel Ongoing
Process Failure
33 Domestic PST's Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory
testing- 80 3.2 Low
Operational monitoring needed with Actions as per
Alert LevelFollow Alert Level actions
C Morkel
C PaulseOngoing
Electrical Failure
34 Biofilters Motor failure of Arms Y 1 3 3 Low Operation & Maintenance - 50 1.5 None Operational and Maintenance occurs reactivelyMotors to be serviced as per O&M
ManualC Morkel Ongoing
Mechanical Failure
35 Biofilters Splitter Tower Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year C Morkel Ongoing
Structural Failure
36 Biofilters Splitter Tower Tower Y 1 2 2 LowTower has been replaced as part of
upgrading100 0 None
The existing tower was replaced during upgrading
of WWTW
Inspection of new Tower once a
yearC Morkel Ongoing
Mechanical Failure
37 Biofilters Gearbox failure on biofilter arms Y 2 2 4 Low Operation & Maintenance 50 2 Low Operational and Maintenance occurs reactivelyInspections & maintenance to
occur pro-activelyC Morkel & Process Controllers Ongoing
Structural Failure
38 Biofilters Old Biofilter walls Y 5 5 25 High Structure strapping 10 22.5 Mediumcurrently strapping is used to reinforce broken
brickwork outer walls
Refurbish walls as part of future
upgradeR Brown & Consultants 2016
Process Failure
39 Biofilters Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory
testing80 3.2 Low
Operational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Electrical Failure
40 Humus Tanks Motor on sludge release arms Y 2 3 6 Low Operation & Maintenance 50 3 Low Reactive Maintenance at the moment Pro-active Maintenance required C Morkel & R Brown Ongoing
Mechanical Failure
41 Humus Tanks Gearbox on sludge arms Y 1 2 2 Low Operation & Maintenance 50 1 None Reactive Maintenance at the moment Pro-active Maintenance required C Morkel & R Brown Ongoing
Pa
arl
WW
TW
Pri
ma
ry S
ett
lin
g T
an
ks
Bio
filt
ers
Bio
filt
ers
Hu
mu
s T
an
ks
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Structural Failure
42 Humus Tanks Humus Tank Structure Y 1 4 4 Low Inspection during Cleaning 80 0.8 NoneDuring Cleaning operation an inspection of the
structure must occurInspections during cleaning C Morkel Ongoing
Process Failure
43 Humus Tanks Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory
testing80 3.2 Low
Operational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Electrical Failure
44 Parshall Flume Ultrasonic Meter Y 1 4 4 Low Reactive Maintenance 80 0.8 NoneIf no Flow is measured, Mass Balance affected or
risk of overflowSpeedy Reactive Maintenance C Morkel Ongoing
45 Screw Pumps MCC Boards Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Screw is available (recently upgraded) Speedy Reactive Maintenance C Morkel Ongoing
Mechanical Failure
46 Screw Pumps Gearboxes for screw pumps Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Screw is available (recently upgraded) Speedy Reactive Maintenance C Morkel Ongoing
Structural Failure
47 Screw Pumps Pumping Station Structure Y 1 5 5 LowInspection of structure during screw
maintenance80 1 None
Pumping Station is new and need only be inspected
during servicing of screwsInspection during screw service C Morkel Ongoing
Electrical Failure
48 Anaerobic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingC Morkel Ongoing
Mechanical Failure
49 Anaerobic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingC Morkel Ongoing
Structural Failure
50 Anaerobic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only
need inspection once it is cleaned in future
Inspection during sludge removal
in futureC Morkel Ongoing
Electrical Failure
51 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingC Morkel Ongoing
52 Anoxic Zone Recycle Pump Motors and MCC Y 1 4 4 Low Reactive Maintenance 80 0.8 None The Pumps are new and need little maintenancePro-Active Maintenance and
ServicingC Morkel Ongoing
Hu
mu
s T
an
ks
Scr
ew
Pu
mp
ing
Sta
tio
n
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Mechanical Failure
53 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingC Morkel Ongoing
54 Anoxic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None Reactive Maintenance C Morkel Ongoing
Structural Failure
55 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only
need inspection once it is cleaned in future
Inspection during sludge removal
in futureC Morkel Ongoing
Electrical Failure
56 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFacility available for removal of aerator from pond
for repair
Hour Logging, Pro-Active
Maintenance and ServicingC Morkel & Process Controllers Ongoing
57 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None Reactive Maintenance C Morkel Ongoing
Mechanical Failure
58 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFacility available for removal of aerator from pond
for repair
Hour Logging, Pro-Active
Maintenance and ServicingC Morkel & Process Controllers Ongoing
59 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None Reactive Maintenance C Morkel Ongoing
Process Failure
60 Aerobic Zone Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
C Morkel & C Paulse & R Brown Ongoing
Mechanical Failure
61 Clarifier Splitter Box Sluice gates Y 1 3 3 Low Operation & Maintenance 100 0 None Inspection must occur and sluices testedTest Sluice Gates at least once a
year.C Morkel Ongoing
Structural Failure
62 Clarifier Splitter Box Splitter Box Structure Y 1 5 5 Low Inspection of Structure 100 0 NoneInspection must occur during testing of sluices
tested
Inspect structure during sluice gate
serviceC Morkel Ongoing
Electrical Failure
63 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 NoneReactive Maintenance at present, however one of
the clarifiers is newly constructed
Pro-Active Maintenance Required
& servicingC Morkel Ongoing
Mechanical Failure
64 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 LowReactive Maintenance at present, however one of
the clarifiers is newly constructed
Pro-Active Maintenance Required
& servicingC Morkel Ongoing
Structural Failure
65 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning C Morkel Ongoing
Process Failure
66 Clarifier Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Structural Failure
67 New Clarifier Clarifier Structure too low Y 4 4 16 Medium - 0 16 Medium
The clarifier structure was constructed low in the
ground and the possibility exists for someone to
fall into the clarifier as there is no handrail around
the clarifier
Construct handrail around clarifier
with apronR Brown & Consultants 2016
Electrical Failure
67 Recycle Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalC Morkel & Process Controllers Ongoing
Mechanical Failure
68 Recycle Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalC Morkel & Process Controllers Ongoing
Structural Failure
69 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 NoneTwo Pumping stations are available to allow
inspection of one while other is operationalInspect Structure during cleaning C Morkel Ongoing
Electrical Failure
70 Waste Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalC Morkel & Process Controllers Ongoing
Mechanical Failure
71 Waste Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalC Morkel & Process Controllers Ongoing
Structural Failure
Pa
arl
WW
TW
Act
iva
ted
Slu
dg
e R
ea
cto
rC
lari
fie
rsR
ecy
cle
& W
ast
e S
lud
ge
Pu
mp
ing
Sta
tio
n
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
72 Waste Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 NoneTwo Pumping stations are available to allow
inspection of one while other is operationalInspect Structure during cleaning C Morkel Ongoing
Electrical Failure
73 Belt Presses Belt Press Motors N 1 2 2 Low Reactive Maintenance 80 0.4 None 4 Belt Presses available Reactive Maintenance C Morkel Ongoing
74 Belt Presses Power failure N 1 2 2 Low Standby generator on site 80 0.4 None
Mechanical Failure
75 Belt Presses Belt Presses N 1 2 2 Low Reactive Maintenance 80 0.4 None 4 Belt Presses available Reactive Maintenance C Morkel Ongoing
Structural Failure
76 Dewatering Building Dewatering Building Structure Y 1 3 3 Low Inspection of Building 100 0 NoneBuilding is new and does not handle effluent, only
sludgeVisual inspection once a year C Morkel Ongoing
Structural Failure
77 Tanks Dome structure on Tanks Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low
Inspection of the dome must occur
at regular interval as determined
by a structural Engineer
C Morkel & R Brown & Consultant Ongoing
Structural Failure
78 Digester Structure of digester Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low
Inspection of the dome must occur
at regular interval as determined
by a structural Engineer
C Morkel & R Brown & Consultant Ongoing
Mechanical Failure
79 Digester Mixer Motors Y 2 5 10 Low Reactive Maintenance 80 2 LowProactive maintenance & servicing
requiredC Morkel Ongoing
General
80 Digester Deep Structure Y 5 5 25 High - 0 25 HighNo life buoy or safety ropes in a very deep
structure
Provide life buoys and safety ropes
for structureC Morkel & R Brown & Consultant 2013
General
81 Incinerators Incinerators very old Y 4 4 16 Medium - 0 16 MediumThe incinerators are very old and parts have
become hard to source
Upgrade of the incinerators must
be investigated as part of future
upgrade
C Morkel & R Brown & Consultant 2016
General
82 Generator Nearing end of service life Y 2 5 10 Low - 0 10 Low
The generator are very old and parts have become
hard to source, however some new generators are
currently under contract to be installed.
Upgrade of the generator must be
investigated as part of future
upgrade.
C Morkel & R Brown & Consultant 2016
Structural Failure
83 Maturation Ponds Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
Process Failure
84 Maturation Ponds Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Electrical Failure
85 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumWarning lights checked daily, with Reactive
Maintenance and Standby Generator on Site100 0 None Weekly inspection of Component
C Morkel
C PaulseOngoing
86 Chlorination Store Room Dosing Electronics Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low Weekly inspection of Component
C Morkel
C PaulseOngoing
Structural Failure
87 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 None Inspect Structure once a Year C Morkel Yearly
Structural Failure
88 Chlorination Channel Channel Structure Y 1 5 5 Low Inspection of Structure 80 1 None Inspect Structure once a Year C Morkel Yearly
Process Failure
89 Chlorination Channel Compliance Monitoring Y 5 5 25 High24h Compliance Monitoring with on site lab.
Newly refurbished90 2.5 Low
Compliance Monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C Paulse & R BrownOngoing
General
90 Laboratory New Laboratory Chemical Room Y 1 2 2 LowNew chemical room with warning light and
extractor fans90 0.2 None -
Ensure all control measures are
checked on regular basis C Paulse & R BrownOngoing
Electrical Failure
91 Transformer Transformers on site (4 No) Y 5 5 25 HighOperation and Maintenance from
Drakenstein Electrical Department0 25 High
Drakenstein Electrical Department is laboring under
capacity constraints and maintenance cannot
always be effected in time
Maintenance schedule for all
transformers which MUST be
adhered to and additional staffing
in the Electrical Department
D du Plessis Ongoing
Lab
ora
tory
Ele
ctri
cal
Tra
nsf
orm
er
Pri
ma
ry G
as
Dig
est
ers
Se
con
da
ry G
as
Dig
est
er
Inci
ne
rato
rsG
en
era
tor
Ma
tura
tio
n P
on
ds
Ch
lori
na
tio
n
Pa
arl
WW
TW
De
wa
teri
ng
Fa
cili
tyM
eth
an
e T
an
ks
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
92
Ge
nse
t
Genset Switch Over Board Y 4 5 20 Medium - 0 20 MediumThe existing switch board is old and is in need of
upgrading with new switchgear, etc.
Investigate upgrading of switch
board as part of future upgrade of
works
C Morkel & R Brown & Consultant 2016
General
93 General Security N 1 2 2 LowNew security fence installed and Security
provided at night95 0.1 None
Reactive Maintenance on fence
may be requiredC Morkel ongoing
94 General Site Lighting Y 3 5 15 Medium Existing high mast lighting 50 7.5 LowInvestigate additional high mast
lighting when requiredC Morkel & R Brown & Consultant 2016
95 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown & Consultant 2013 R 700 k
96 General Signage Y 2 5 10 Low Existing signage on site 50 5 Low Additional Signage may be requireInvestigate additional signage as
part of future upgradeR Brown & Consultant 2016
Paarl
WWTW
Ge
ne
ral
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Inlet Works Power failure Y 3 4 12 Low Standby generator on site - 100 0 None
2 Parshall Flume Ultrasonic Meter Y 1 4 4 Low Reactive Maintenance 80 0.8 NoneIf no Flow is measured, Mass Balance affected or
risk of overflowSpeedy Reactive Maintenance M Krautz Ongoing
Mechanical Failure
3 Inlet Works Hand Sluices Y 1 4 4 Low Inspection of Sluices and Standby Stream 80 0.8 NoneInspect and test sluices once a
yearM Krautz Yearly
4 Inlet Works Hand Raked Screens Y 2 3 6 Low
Permanent Cleaning of Screen throughout
the day, daily inspection according to
checklists
90 0.6 None
Permanently posted staff clean hand raked screen,
low screenings volume from Pearl Valley and Val de
Vie. Not foreseen that mechanical screen is
required.
- M Krautz Ongoing
Process Failure
5 Inlet Works Influent compliance Y 2 5 10 Low
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
- 80 2 Low
Operational monitoring is to occur to operational
monitoring alert level. However time sequencing
can be investigated due to low flow conditions at
times
Ensure monitoring occurs as
scheduled
M Krautz & C Paulse & R Brown &
Consultants re time scheduling
Ongoing
Monitoring
& 2017 Time
Scheduling
Structural Failure
6 Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year M Krautz Yearly
7 Splitter box Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year M Krautz Yearly
Structural Failure
8 Splitter box Splitter Box Structure Y 1 5 5 Low Inspect Structure During Maintenance - 100 0 None Inspect Structure during Maintenance Investigate structure once a year M Krautz Yearly
Electrical Failure
9 Anaerobic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need
little maintenance at the present
Pro-Active Maintenance and
ServicingM Krautz Ongoing
Mechanical Failure
10 Anaerobic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need
little maintenance at the present
Pro-Active Maintenance and
ServicingM Krautz Ongoing
Structural Failure
11 Anaerobic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is relatively new and will only need
inspection once it is cleaned in future
Inspection during sludge removal
in futureM Krautz Ongoing
Electrical Failure
12 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need
little maintenance at the present
Pro-Active Maintenance and
ServicingM Krautz Ongoing
13 Anoxic Zone Recycle Pump Motors and MCC Y 1 4 4 LowStandby Pump available and reactive
maintenance80 0.8 None
The Pumps are relatively new and need little
maintenance
Pro-Active Maintenance and
ServicingM Krautz Ongoing
Mechanical Failure
14 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need
little maintenance at the present
Pro-Active Maintenance and
ServicingM Krautz Ongoing
15 Anoxic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None
The Pumps are relatively new and need little
maintenance
Pro-Active Maintenance and
ServicingM Krautz Ongoing
Structural Failure
16 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is relatively new and will only need
inspection once it is cleaned in future
Inspection during sludge removal
in futureM Krautz Ongoing
Electrical Failure
17 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowThe Aerators are relatively new and therefore need
little maintenance at the present
Hour Logging, Pro-Active
Maintenance and ServicingM Krautz & Process Controllers Ongoing
18 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None
The Pumps are relatively new and need little
maintenance
Pro-Active Maintenance and
ServicingM Krautz Ongoing
Mechanical Failure
19 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowThe Aerators are relatively new and therefore need
little maintenance at the present
Hour Logging, Pro-Active
Maintenance and ServicingM Krautz & Process Controllers Ongoing
20 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None
The Pumps are relatively new and need little
maintenance
Pro-Active Maintenance Required
& servicingM Krautz Ongoing
Process Failure
21 Aerobic Zone Operational Monitoring Y 2 5 10 Low
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 2 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with adjustments at
alert levels, add additional
monitoring to optimize process
M Krautz & C Paulse & R Brown Ongoing
Pe
arl
Va
lle
y W
WT
W
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PEARL VALLEY WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Inle
t W
ork
sA
ctiv
ate
d S
lud
ge
Re
act
or
Act
iva
ted
Slu
dg
e R
ea
cto
rs
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PEARL VALLEY WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Electrical Failure
22 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 None Reactive Maintenance at presentPro-Active Maintenance Required
& servicingM Krautz Ongoing
Mechanical Failure
23 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 Low Reactive Maintenance at presentPro-Active Maintenance Required
& servicingM Krautz Ongoing
Structural Failure
24 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning M Krautz Ongoing
Process Failure
25 Clarifier Operational Monitoring Y 2 5 10 Low
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
M Krautz
C PaulseOngoing
Electrical Failure
26 Recycle Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalM Krautz & Process Controllers Ongoing
Mechanical Failure
27 Recycle Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalM Krautz & Process Controllers Ongoing
Structural Failure
28 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning M Krautz Ongoing
Electrical Failure
29 Belt Presses Belt Press Motors N 1 2 2 Low Reactive Maintenance 80 0.4 NoneMore than one Belt Presses available and low
sludge volumesReactive Maintenance M Krautz Ongoing
30 Belt Presses Power failure N 1 2 2 Low Standby generator on site 80 0.4 None
Mechanical Failure
31 Belt Presses Belt Presses N 1 2 2 Low Reactive Maintenance 80 0.4 NoneMore than one Belt Presses available and low
sludge volumesReactive Maintenance M Krautz Ongoing
Structural Failure
32 Dewatering Building Dewatering Building Structure Y 1 3 3 Low Inspection of Building 100 0 NoneBuilding is new and does not handle effluent, only
sludgeVisual inspection once a year M Krautz Ongoing
Electrical Failure
33 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low
An audit has been performed and corrective
measures have been identified.Weekly inspection of Component
M Krautz
C Paulse & R Brown
Ongoing &
End 2012 for
Corrective
Measures
34 Chlorination Store Room Dosing Electronics Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low
An audit has been performed and corrective
measures have been identified.Weekly inspection of Component
M Krautz
C Paulse
Ongoing &
End 2012 for
Corrective
Measures
Structural Failure
35 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 NoneAn audit has been performed and corrective
measures have been identified.Inspect Structure once a Year M Krautz Yearly
Structural Failure
36 Chlorination Channel Channel Structure Y 1 5 5 Low Inspection of Structure 80 1 NoneAn audit has been performed and corrective
measures have been identified.Inspect Structure once a Year M Krautz Yearly
Structural Failure
37 Maturation Ponds Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
Process Failure
38 Maturation Ponds Compliance Monitoring Y 5 5 25 High
Compliance Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott) and Maturation Pond Maintenance
80 5 Low
Compliance monitoring to occur to alert levels with
corrective actions as per Alert Level, Algal problems
occurred in retention pond and retention time was
reduced, however sediment transport remains
problematic
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
M Krautz
C PaulseOngoing
Mechanical Failure
39 Pumping Station Pumps Y 2 1 2 Low2 Pumps : 1 Duty 1 Standby and both new
pumps90 0.2 None -
Pro-Active Maintenance Required
& servicingM Krautz Ongoing
40 Pumping Station Screening Basket Y 2 1 2 LowDaily inspection according to pumping
station checklist90 0.2 None Low screenings volume at the pumping station Daily inspections M Krautz Ongoing
Structural Failure
41 Pumping Station Pumping Station Structure Y 2 1 2 Low - 0 2 Low Structure is newInspection of structure during
cleaningM Krautz & R Brown & Consultants Ongoing
Se
wa
ge
Pu
mp
ing
Sta
tio
n
Pe
arl
Va
lle
y W
WT
W
De
wa
teri
ng
Fa
cili
tyM
atu
rati
on
Po
nd
sR
ecy
cle
Slu
dg
e P
um
pin
g S
tati
on
Ch
lori
na
tio
n
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PEARL VALLEY WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Electrical Failure
42 Pumping Station Power failure Y 5 4 20 Medium Standby generator on site & Overflow pond 90 2 Low -
Pro-Active Maintenance Required
& servicing of standby generator
required
M Krautz & R Brown Ongoing
43 Pumping Station Telemetry Y 4 5 20 Medium - 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
Mechanical Failure
44 Sludge Drying Beds Drainage Pump Y 4 4 16 Medium Reactive Maintenance 100 0 None New Pump Currently sourced
Monitor supplier performance and
pump performance after
commissioning
R Brown 2012
General
45 General Security at works Y 4 6 24 Medium - 0 24 Medium No Security on site
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
46 General Office Facilities Y 5 6 30 High - 0 30 High No office on site. Non-Compliance with OSH ActProvide office facilities as part of
the future upgradeR Brown & Consultant 2016
Ge
ne
ral
Se
wa
ge
Pu
mp
ing
Sta
tio
n
Pe
arl
Va
lle
y W
WT
W
Slu
dg
e D
ryin
g
Be
ds
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Pumping Station Power failure Y 5 5 25 High - 0 25 HighNo Standby Generator on site, Urgently required as
this is the closest pumping station to the Berg RiverProvide standby Generator to site R Brown & Consultant End 2013
Process Failure
2 Pumping Station Flow meter Y 3 5 15 Medium - 0 15 Medium Flow meter has not been commissioned Commission Flow meter R Brown & Consultant End 2013
Mechanical Failure
3 Pumping Station Screening of Sewage Y 4 5 20 MediumBasket screen, inspected daily according to
pumping station checklist90 2 Low -
Ensure inspections occur regularly
with cleaning as requiredD Claasens Ongoing
4 Pumping Station Pumps Y 2 5 10 Low
New pumps recently installed, reactive
maintenance by dedicated maintenance
team
90 1 None - Reactive Maintenance D Claasens Ongoing
Structural Failure
5 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 None -Inspection of structure during
cleaningD Claasens Ongoing
General
6 Pumping Station No permanent supervision Y 5 5 25 High Daily inspections only 0 25 HighSupervision required as pumping station is closest
to Berg River
Investigate need for permanent
supervision on site or telemetry
system
R Brown & Consultant 2014
7 Pumping Station Telemetry at pumping Station Y 2 3 6 Low - 0 6 Low
Telemetry required as pumping station is closest to
Berg River, Contractor appointed to upgrade entire
telemetry network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
Electrical Failure
8 Pumping Station Power failure Y 2 5 10 Low Standby Generator on site 90 1 None Standby Generator on siteProactive maintenance and
servicing required for GeneratorD Claasems Ongoing
Mechanical Failure
9 Pumping Station Screening of Sewage Y 2 5 10 LowMechanical Screens, inspected daily
according to pumping station checklist90 1 None -
Ensure inspections occur regularly
with cleaning as required with
reactive maintenance for screens
D Claasens Ongoing
10 Pumping Station Pumps Y 2 5 10 Low4 Pumps with 3 Duty, inspected daily
according to pumping station checklist90 1 None -
Ensure inspections occur regularly
with cleaning as required with
reactive maintenance for Pumps
D Claasens Ongoing
Structural Failure
11 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 None -Inspection of structure during
cleaningD Claasens Ongoing
General
11 Pumping Station Security Y 5 5 25 High3m high wall with barbed wire, fencing,
security lights and Armed response80 5 Low
High vandalism rate at this pumping station forced
extreme security measures
Investigate inclusion of site into
perimeter of new fence around
WWTW and Land fill site
R Brown & Consultant 2014
General
12 Pumping Station Design Capacity Exceedance Y 3 5 15 Medium - 0 15 Medium Capacity problems observed in past
Investigate capacity requirement
of this pumping station (currently
T3 pumps installed)
R Brown & Consultant 2014
Electrical Failure
13 Pumping Station Power failure Y 2 5 10 Low Standby Generator on site 90 1 None Standby Generator on siteProactive maintenance and
servicing required for GeneratorD Claasems Ongoing
Mechanical Failure
14 Pumping Station Screening of Sewage Y 3 5 15 Medium - 0 15 MediumContract has been issued for provision of a
mechanical screen
Monitor contractor performance
and Mechanical Screen
performance after commissioning
R Brown & Consultant & D
ClaasensOngoing
15 Pumping Station Pumps Y 2 5 10 Low2 Pumps with 1 Duty, inspected daily
according to pumping station checklist90 1 None -
Ensure inspections occur regularly
with cleaning as required with
reactive maintenance for Pumps
D Claasens Ongoing
Structural Failure
16 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 None -Inspection of structure during
cleaningD Claasens Ongoing
General
17 Pumping Station Security Y 5 5 25 High Broken fencing and Armed response 25 18.75 MediumHigh vandalism rate at this pumping station
requires security measures
Investigate construction of new
fencing and possibly alarm systemR Brown & Consultant 2014
18 Pumping Station Telemetry at pumping Station Y 3 5 15 Medium - 0 15 Medium
Telemetry required as pumping station is closest to
Berg River, Contractor appointed to upgrade entire
telemetry network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
We
llin
gto
n W
WT
W
Industrial Park
Sewage
Pumping
Station
(Pacmar)
Newton
Sewage
Pumping
Station
Erf 8000
Sewage
Pumping
Station
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
19
Pentz Street
Sewage
Pumping
Station
20
Wellington
Industries
Pumping
Station
General
21 General Plant Design Capacity Exceedance Y 5 5 25 High 0 25 HighUpgrading of Plant Required, All flows pumped to
WWTW therefor also may need a balancing dam
Upgrade entire Plant and
investigate the construction of
balancing dam to balance flows
from all the pumping stations
D Claasens & R Brown &
Consultants2016
Electrical Failure
22 Inlet Works Power failure Y 5 5 25 High No Standby Generator on site - 0 25 High No Standby Generator on SiteInstall Standby Generator as part
of upgrade
D Claasens & R Brown &
Consultants2016
23 Inlet Works Grit Remover (Vortex) Motor failure N 2 3 6 Low 2No so will be able to function with 1 50 3 Low Backup grit removal D Claasens Ongoing
Mechanical Failure
24 Inlet Works Grit removal (Vortex) Gearbox N 1 2 2 Low 2No so will be able to function with 1 100 0 None Backup grit removal D Claasens
Structural Failure
25 Inlet Works Inlet works N 1 4 4 Low Inspection of Structure 0 4 LowStructure is old but will be upgraded as part of
WWTW upgrade
Upgrade structure as part of
WWTW upgrade
D Claasens & R Brown &
Consultants2015
Process Failure
26 Inlet Works Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
- 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
D Claasens
C PaulseOngoing
Mechanical Failure
27 Splitterbox Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Yearly
Structural Failure
28 Splitterbox Structure Y 1 5 5 Low Inspection of Structure - 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly
Electrical Failure
29 PST's Motor for Scum plate bridge Y 2 3 6 Low Operation & Maintenance - 50 3 Low Re-active maintenance at the moment Pro-active maintenanceR Brown
D Claasens2015
Structural Failure
30 PST's Structure Y 1 5 5 Low Inspection of structure - 50 2.5 LowOne of the PST's recently inspected and needed
refurbishmentInspect Structure once a Year D Claasens Yearly
Process Failure
31 PST's Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
- 80 3.2 LowOperational monitoring needed with Actions as per
Alert LevelFollow Alert Level actions
D Claasens
C PaulseOngoing
Mechanical Failure
33 Biofilters Splitter Tower Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Ongoing
Structural Failure
34 Biofilters Splitter Tower Tower Y 1 5 5 Low Inspection of structure 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly
Electrical Failure
32 Biofilters Motor failure of Arms Y 1 3 3 Low Operation & Maintenance - 50 1.5 None Operational and Maintenance occurs reactivelyMotors to be serviced as per O&M
ManualD Claasens Ongoing
Mechanical Failure
35 Biofilters Gearbox failure on biofilter arms Y 2 2 4 Low Operation & Maintenance 50 2 Low Operational and Maintenance occurs reactivelyInspections & maintenance to
occur pro-activelyD Claasens & Process Controllers Ongoing
Structural Failure
36 Biofilters Biofilter Structure Y 1 5 5 Low Inspection of structure 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly
Process Failure
37 Biofilters Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 3.2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
New Contract Out for Construction of a new Pumping Station at Pentz Street. A Full HAZOP was performed for the Pumping Station. Refer to HAZOP for Details
This Pumping Station is to be decommissioned and sewage will drain towards the new Pentz Street Pumping Station
We
llin
gto
n W
WT
W
Inle
t W
ork
sP
rim
ary
Se
ttli
ng
Ta
nk
sB
iofi
lte
rs
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Mechanical Failure
38 Humus Tanks Splitter Box Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Yearly
Structural Failure
39 Humus Tanks Splitter Box Structure Y 1 5 5 Low Inspection of Structure - 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly
Electrical Failure
40 Humus Tanks Motor on sludge release arms Y 2 3 6 Low Operation & Maintenance 50 3 Low Reactive Maintenance at the moment Pro-active Maintenance required D Claasens & R Brown Ongoing
Mechanical Failure
41 Humus Tanks Gearbox on sludge arms Y 1 2 2 Low Operation & Maintenance 50 1 None Reactive Maintenance at the moment Pro-active Maintenance required D Claasens & R Brown Ongoing
Structural Failure
42 Humus Tanks Humus Tank Structure Y 1 4 4 Low Inspection during Cleaning 80 0.8 NoneDuring Cleaning operation an inspection of the
structure must occurInspections during cleaning D Claasens Ongoing
Process Failure
43 Humus Tanks Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 3.2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
Electrical Failure
44 Parshall Flume Ultrasonic Meter Y 1 4 4 Low Reactive Maintenance 80 0.8 NoneIf no Flow is measured, Mass Balance affected or
risk of overflowSpeedy Reactive Maintenance D Claasens Ongoing
45 Humus Effluent Pumps Motor's and MCC Boards Y 2 3 6 Low Reactive Maintenance 80 1.2 None Standby Pumps available Speedy Reactive Maintenance D Claasens Ongoing
Mechanical Failure
46 Humus Effluent Pumps Pumps Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Pumps available Speedy Reactive Maintenance D Claasens Ongoing
Structural Failure
47 Humus Effluent Pumps Pumping Station Structure Y 1 5 5 LowInspection of structure during screw
maintenance80 1 None
Pumping Station must be inspected during servicing
of pumpsInspection during Pump service D Claasens Ongoing
Electrical Failure
48 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingD Claasens Ongoing
Mechanical Failure
49 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little
maintenance at the present
Pro-Active Maintenance and
ServicingD Claasens Ongoing
Structural Failure
50 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only
need inspection once it is cleaned in future
Inspection during sludge removal
in futureD Claasens Ongoing
Electrical Failure
51 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFixed aerator on pedestal so able to remove
aerator from pond for repair
Hour Logging, Pro-Active
Maintenance and ServicingD Claasens & Process Controllers Ongoing
52 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None Reactive Maintenance D Claasens Ongoing
Mechanical Failure
53 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFixed aerator on pedestal so able to remove
aerator from pond for repair
Hour Logging, Pro-Active
Maintenance and ServicingD Claasens & Process Controllers Ongoing
54 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive
maintenance80 1 None Reactive Maintenance D Claasens Ongoing
Process Failure
55 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 4 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
D Claasens & C Paulse & R Brown Ongoing
Electrical Failure
56 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 None Reactive Maintenance at presentPro-Active Maintenance Required
& servicingD Claasens Ongoing
Hu
mu
s T
an
ks
We
llin
gto
n W
WT
W
Hu
mu
s T
an
ks
Hu
mu
s T
an
k E
fflu
en
t P
um
pin
g S
tati
on
Act
iva
ted
Slu
dg
e R
ea
cto
r
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Mechanical Failure
57 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 Low Reactive Maintenance at presentPro-Active Maintenance Required
& servicingD Claasens Ongoing
Structural Failure
58 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning D Claasens Ongoing
Process Failure
59 Clarifier Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 4 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
Electrical Failure
60 Recycle Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalD Claasens & Process Controllers Ongoing
Mechanical Failure
61 Recycle Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalD Claasens & Process Controllers Ongoing
Structural Failure
62 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning D Claasens Ongoing
Electrical Failure
63 Waste Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalD Claasens & Process Controllers Ongoing
Mechanical Failure
64 Waste Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is
operationalD Claasens & Process Controllers Ongoing
Structural Failure
65 Waste Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning D Claasens Ongoing
Electrical Failure
66 Chlorination Store Room Warning Lights outside building Y 5 5 25 High
Reactive Maintenance and No Standby
Generator on Site, Inspection completed and
Certificate for compliance obtained
90 2.5 Low A Standby Generator on site is imperative
Weekly inspection of Component
and installation of Standby
Generator on site
D Claasens
C Paulse & R Brown & Consultants2015
67 Chlorination Store Room Dosing Electronics Y 5 5 25 High
Reactive Maintenance and No Standby
Generator on Site, Inspection completed and
Certificate for compliance obtained
90 2.5 Low A Standby Generator on site is imperative
Weekly inspection of Component
and installation of Standby
Generator on site
D Claasens
C Paulse & R Brown & Consultants2015
Structural Failure
68 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 None Inspect Structure once a Year D Claasens Yearly
Structural Failure
69 Maturation Ponds Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
Process Failure
70 Maturation Ponds Compliance Monitoring Y 5 5 25 High
Compliance Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
80 5 LowCompliance monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
General
71 Sludge Drying Beds Design Capacity Exceedance Y 5 5 25 High - 0 25 High2 Waste ponds, Large Sludge Volume coming into
works.
Investigate sludge handling (e.g.
Dewatering Plant) as part of future
upgrade of works
D Claasens & R Brown &
Consultants2016
General
72 Digester No Gas Tank Y 4 5 20 Medium - 0 20 Medium
The plant has Gas Digesters but no gas tank. A
waste to energy project has been initiated which
could utilize the gas
Investigate gas storage or
conveyance to waste to energy site
as part of future upgrade of works
D Claasens & R Brown &
Consultants2016
General
73 Incinerator No incinerator on site for screenings Y 4 5 20 MediumScreenings conveyed to Paarl WWTW for
Incineration50 10 Low -
Investigate on site incinerators or
conveyance to waste to energy site
as part of future upgrade of works
D Claasens & R Brown &
Consultants2016
We
llin
gto
n W
WT
W
Re
cycl
e &
Wa
ste
Slu
dg
e P
um
pin
g S
tati
on
Ch
lori
na
tio
nM
atu
rati
on
Po
nd
sS
lud
ge
Dry
ing
Be
ds
Ga
s D
ige
ste
rIn
cin
era
tor
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
General
74 Personnel Facilities Offices Y 4 5 20 MediumSome office space provided with limited
ablution facilities10 18 Medium Existing facilities do not comply with OSH Act
Investigate the construction of a
new office building with ablution
facilities all to comply with the
OSH Act as part of future upgrade
of works
D Claasens & R Brown &
Consultants2016
75 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
76 General Site Lighting Y 5 4 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient
Investigate the new or additional
high mast site lighting as part of
future upgrade of works
D Claasens & R Brown &
Consultants2016
77 General Security Y 5 5 25 High Existing Fence 25 18.75 MediumContract for a new security fence has been issued
and is underway
Monitor contractor performance
and maintain new fence after
commissioning
D Claasens & R Brown &
ConsultantsEnd 2012
78 General Signage Y 5 5 25 High - 0 25 HighSignage is required on site to comply with various
statutory regulations including the OSH Act
Investigate provision signage as
part of future upgradeR Brown & Consultant End 2013
Ge
ne
ral
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Process Failure
1 Inlet Influent compliance Y 4 5 20 MediumOperational monitoring i.e. Laboratory
testing- 80 4 Low
Operational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
Structural Failure
2 Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly
Structural Failure
3 Evaporation pond 1 Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
4 Evaporation pond 2 Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
5 Evaporation pond 3 Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None
Process Failure
6 Evaporation pond 3 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
Investigate need for Mini Lab. On
site
C Morkel
C Paulse & R BrownOngoing
7 Evaporation Ponds Ground Water Monitoring Wells Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Structural Failure
8 Sump Structure Sump Structure Size Y 3 5 15 MediumDaily inspection of sump according to
Pumping Station checklist25 11.25 Low
Current sump structure to large and has overflow
walls and no Mechanical screen. Screenings
accumulate in first chamber and must be manually
removed
Investigate upgrade of pumping
station and installation of
Mechanical Screen
R Brown & Consultants 2017
Mechanical Failure
9 Pumps Pump Failure Y 3 5 15 MediumReactive maintenance with 24h turn around
time50 7.5 Low
Pumps may experience problems due to
screenings clogging the pumps
In the interm continue daily
inspections and Investigate
upgrade of pumping station and
installation of Mechanical Screen
in future
C Morkel & R Brown &
Consultants
Ongoing &
2017
Electrical Failure
10 Pumps No Standby Power Y 5 5 25 High - 0 25 HighAt the moment no Standby Power at the pumping
station
Investigate supply of standby
power generator at pumping
station
C Morkel & R Brown &
Consultants2017
General
11 General Telemetry at Pumpung Station Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : HERMON WWTW
Inherent Risk Score (before
consideration of any controls)
He
rmo
n S
ew
ag
e P
um
pin
g S
tati
on
He
rmo
n W
WT
W
Residual Risk Score
Ev
ap
ora
tio
n P
on
ds
Inle
t
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Inlet Works Power failure Y 5 5 25 High No Standby generator on site - 0 25 High No Standby Generator on site
Install Standby Generator as part
of WWTW upgrade. Contractor
appointed and supply of generator
imminent
T Simons & R Brown & Consultant End 2012 R 350 k
2 Inlet Works Flow Meter failure Y 5 2 10 Low No Standby generator on site - 0 10 Low No Standby Generator on site
Install Standby Generator as part
of WWTW upgrade. Contractor
appointed and supply of generator
imminent
T Simons & R Brown & Consultant End 2012 N/A
Mechanical Failure
3 Inlet Works Hand Sluices Y 1 4 4 Low Inspection of Sluices and Standby Stream 80 0.8 None Daily inspections of sluices occur T Simons Daily N/A
4 Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day70 4.5 Low
Permanently posted staff clean hand raked screen
and a new Mechanical screen will be provided at
the Saron Sewage pumping station in new contract
Monitor screenings amount after
commissioning of mechanical
screen at Saron Sewage pumping
station
T Simons & R Brown & ConsultantsEnd 2012
and OngoingN/A
5 Parshall Flume Ultrasonic Meter Y 1 4 4 Low Reactive Maintenance 80 0.8 NoneIf no Flow is measured, Mass Balance affected or
risk of overflowSpeedy Reactive Maintenance T Simons Ongoing
Process Failure
6 Inlet Works Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
- 90 2 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
T Simons
C PaulseOngoing
7 Inlet Works Design Capacity N 4 5 20 Medium 0 20 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Structural Failure
8 Inlet Works Inlet Works Structure Y 3 5 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Electrical Failure
9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn
around time
Replaced Mixer and now Pro-
Active Maintenance and ServicingT Simons & C Morkel & R Brown Ongoing
Mechanical Failure
10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn
around time
Replaced Mixer and now Pro-
Active Maintenance and ServicingT Simons & C Morkel & R Brown Ongoing
Structural Failure
11 Anaerobic Zone Zone Structure Y 4 4 16 Medium 0 16 MediumNew Reactor must be constructed as part of
WWTW upgrade
Construct new Reactor as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Electrical Failure
12 Aerobic Zone Aerator Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn
around time
Hour Logging, Pro-Active
Maintenance and Servicing or
possible standby Aerator. Also
investigate timer for low flow
periods
T Simons & Process Controllers & R
BrownOngoing
Mechanical Failure
13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn
around time
Hour Logging, Pro-Active
Maintenance and Servicing or
possible standby Aerator. Also
investigate timer for low flow
periods
T Simons & Process Controllers & R
BrownOngoing
Process Failure
14 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
90 2 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
T Simons & C Paulse & R Brown Ongoing
Electrical Failure
15 Clarifier Bridge motors Y 1 5 5 Low Reactive Maintenance 80 1 NoneReactive maintenance at the present with 24h turn
around time
Pro-Active Maintenance Required
& servicingT Simons & C Morkel & R Brown Ongoing
Mechanical Failure
16 Clarifier Bridge Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 LowReactive maintenance at the present with 24h turn
around time
Pro-Active Maintenance Required
& servicingT Simons & C Morkel & R Brown Ongoing
Structural Failure
17 Clarifier Clarifier Structure Y 3 5 15 Medium Inspection of Structure 0 15 MediumInspection must occur during cleaning, Cracks
observed on outside.
Inspect structure during cleaning,
perform structural investigation
with report
T Simons & C Morkel & R Brown &
Consultants2016
Process Failure
18 Clarifier Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
T Simons
C PaulseOngoing
Electrical Failure
19 Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available but not in sump 25 4.5 Low Standby pump on site but not installed in sump
Investigate installation of standby
pump in sum as part of future
upgrade
T Simons & C Morkel & R Brown &
Consultants2016
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : SARON WWTW
Inherent Risk Score (before
consideration of any controls)
Sa
ron
WW
TW
Residual Risk Score
Inle
t W
ork
sR
ecy
cle
& W
ast
e S
lud
ge
Pu
mp
ing
Sta
tio
nA
ctiv
ate
d S
lud
ge
Re
act
or
Cla
rifi
er
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : SARON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Mechanical Failure
20 Pumping Station Pumps Y 5 5 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump
Investigate installation of standby
pump in sum as part of future
upgrade
T Simons & C Morkel & R Brown &
Consultants2016
Structural Failure
21 Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during cleaning T Simons Ongoing
Electrical Failure
22 Chlorination Store Room Warning Lights outside building Y 5 5 25 HighReactive Maintenance and No Standby
Generator on Site50 12.5 Low
Entire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
23 Chlorination Store Room Dosing Electronics Y 5 5 25 HighReactive Maintenance and No Standby
Generator on Site50 12.5 Low
Entire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
Structural Failure
24 Chlorination Store Room Store Room Structure Y 5 5 25 High Inspection of Structure 50 12.5 LowEntire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
Structural Failure
25 Maturation Ponds Structures across river Y 4 4 16 Medium 0 16 Medium
Structure across river may have leakages in
crossing, relining of 1st pond currently (2012)
underway
Construct new Maturation ponds
closer to the WWTW as part of
upgrading of WWTW
T Simons & R Brown & Consultant 2016
Process Failure
26 Maturation Ponds Compliance Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW lab.
and Monthly Audit by Independent Lab. (A.L.
Abbott)
90 2 LowCompliance monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
T Simons
C PaulseOngoing
Structural Failure
27 Sludge Drying Beds Bed Structures Y 4 6 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished T Simons & R Brown & Consultant 2016
Process Failure
28 Sludge Drying Beds Filter Medium Y 5 3 15 Medium 0 15 MediumWater does not filter through quick enough,
Contractor appointed to refurbish the beds
All beds to be refurbished, monitor
speed of water filtration after
refurbishments are complete
T Simons & R Brown & Consultant 2016
General
29 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
30 General Security Guard at works Y 5 4 20 Medium 0 20 Medium No security guard at the works.
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
31 General Site Lighting Y 5 4 20 Medium 0 20 Medium Minimal site lightingAdditional site lighting must be
provided as part of future upgradeR Brown & Consultant 2016
Sa
ron
WW
TW
Slu
dg
e D
ryin
g B
ed
sG
en
era
lM
atu
rati
on
Po
nd
sC
hlo
rin
ati
on
Re
cycl
e &
Wa
ste
Slu
dg
e
Pu
mp
ing
Sta
tio
n
Re
cycl
e &
Wa
ste
Slu
dg
e
Pu
mp
ing
Sta
tio
n
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness (%)Comment
Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Mechanical Failure
1 Pumping Station Pump Failure Y 1 2 2 Low2 No. Standby pumps with Mechanical
Screen90 0.2 None
Reactive Maintenance only with 24h turn around
time
Ensure standby pumps remain
opperationalR Jacobs Ongoing
Electrical Failure
2 Pumping Station Standby power Y 5 5 25 High - 0 25 High No Standby Power generator available on site
A standby power generator must
be provided for the pumping
station
R Brown 2016
Structural Failure
3 Pumping Station Pumping Station Structure Y 1 5 5 LowDaily Inspection of Structure from Pumping
Station inspection checklist90 0.5 None
Ensure Daily inspections occur
through spot checkingR Jacobs & C Morkel & R Brown Ongoing
Process Failure
4 Inlet Influent compliance Y 4 5 20 Medium
Operational monitoring through weekly
testing as there no effluent outflow from this
evaporation pond system
- 90 2 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
R Jacobs
C PaulseOngoing
Mechanical Failure
5 Inlet Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day90 1.5 None
Permanently posted staff clean hand raked screen,
however low screenings volume due to mechnical
screen at Gouda Sewage Pumping Station
Clean Screen Daily R Jacobs Ongoing
Structural Failure
6 Inlet Works Inlet Works Structure Y 1 5 5 LowDaily Inspection of Structure from WWTW
inspection checklist100 0 None Continue with daily inspections R Jacobs & C Morkel Ongoing
Process Failure
1 Inlet Spetic tank influent compliance Y 4 5 20 Medium - - 0 20 MediumNo monitoring of farms septic tank loadings (e.g.
COD, etc.)
Sampling of farm septic tanks
inffluent must be performed to
gauge impact on process
R Jacobs & C Paulse & R Brown Ongoing
Structural Failure
7 Primary Ponds 1 & 2 Pond Wall Breakage Y 1 6 6 LowDaily inspection according to inspection
checklist & Ponds below Ground60 2.4 Low
Contractor appointed to constuct Gabion
protection
Monitor Daily after Gabion
protection has been constructedR Jacobs Ongoing
8 Secondary Ponds 3 to 6 Pond Wall Breakage Y 1 6 6 LowDaily inspection according to inspection
checklist & Ponds below Ground60 2.4 Low
Contractor appointed to constuct Gabion
protection
Monitor Daily after Gabion
protection has been constructedR Jacobs Ongoing
9 All Ponds Inlet and outlet structures to all ponds Y 1 4 4 LowDaily Inspection of Structures according to
inspection checklist100 0 None The structures were recently constructed Inspect all structures daily C Morkel Weekly
Process Failure
10 Primary Pond 1 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
11 Primary Pond 2 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
12 Secondary Pond 3 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
13 Secondary Pond 4 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
14 Secondary Pond 5 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
15 Secondary Pond 6 Compliance Monitoring Y 5 5 25 High
Compliance Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2.5 LowCompliance monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
16 Evaporation Ponds Ground Water Monitoring Wells Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels with
corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
General
17 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
18 General Security Guard at works Y 5 4 20 Medium 0 20 Medium No security guard at the works.
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
19 General Site Lighting Y 5 4 20 Medium 0 20 Medium Minimal site lightingAdditional site lighting must be
provided as part of future upgradeR Brown & Consultant 2016
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : GOUDA WWTW
Inherent Risk Score (before
consideration of any controls)
Inle
tG
en
era
l
Go
ud
a W
WT
W
Residual Risk Score
Eva
po
rati
on
Po
nd
sG
ou
da
Se
wa
ge
Pu
mp
ing
Sta
tio
n
U:\Werke\0800\0828 - Drakenstein W2RAP\Rep\W2RAP revB 2013\0828 W2RAP Report Rev B Feb 2013.docx
ANNEXURE D :
DRAKENSTEIN MUNICIPALITY :
WASTE WATER INCIDENT MANAGEMENT PROTOCOL
U:\Werke\0800\0828 - Drakenstein W2RAP\Rep\W2RAP revB 2013\0828 W2RAP Report Rev B Feb 2013.docx
ANNEXURE E :
HIGH AND MEDIUM RISK ITEMS FOR WWTW
WITH MITIGATION MEASURES
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Process Failure
11 Domestic Pumping Station Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
12 Domestic Pumping Station Design Capacity Y 4 5 20 Medium - - 0 20 MediumThe existing Pumping Station has a lower capacity
than newly constructed sewer
Investigate New pumping station
with higher capacityR Brown & Consultants 2016
Mechanical Failure
20 Industrial Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day70 4.5 Low Permanently posted staff clean hand raked screen
Investigate installation of
mechanical screens in future
C Morkel & R Brown &
Consultants2016
Process Failure
21 Industrial Inlet Works Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
Process Failure
27 Flocculator Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 3.2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Electrical Failure
28 Flocculator Power failure to bridge Y 3 5 15 Medium - 0 15 MediumNo power to the bridge at present and process is
being affected
Power to be provided to bridge
immediatelyC Morkel & R Brown End 2012
Structural Failure
30 Domestic splitterbox Tower Y 3 5 15 Medium - - 0 15 Medium Tower must be investigatedInvestigate structure of tower and
gratingsR Brown/Sub-consultants 2016
Process Failure
33 Domestic PST's Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 80 3.2 LowOperational monitoring needed with Actions as
per Alert LevelFollow Alert Level actions
C Morkel
C PaulseOngoing
Structural Failure
38 Biofilters Old Biofilter walls Y 5 5 25 High Structure strapping 10 22.5 Mediumcurrently strapping is used to reinforce broken
brickwork outer walls
Refurbish walls as part of future
upgradeR Brown & Consultants 2016
Process Failure
39 Biofilters Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 3.2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Process Failure
43 Humus Tanks Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 3.2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Process Failure
60 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 4 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
C Morkel & C Paulse & R Brown Ongoing
Process Failure
66 Clarifier Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 4 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Structural Failure
67 New Clarifier Clarifier Structure too low Y 4 4 16 Medium - 0 16 Medium
The clarifier structure was constructed low in the
ground and the possibility exists for someone to
fall into the clarifier as there is no handrail around
the clarifier
Construct handrail around clarifier
with apronR Brown & Consultants 2016
Structural Failure
77 Tanks Dome structure on Tanks Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low
Inspection of the dome must
occur at regular interval as
determined by a structural
Engineer
C Morkel & R Brown & Consultant Ongoing
Structural Failure
78 Digester Structure of digester Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low
Inspection of the dome must
occur at regular interval as
determined by a structural
Engineer
C Morkel & R Brown & Consultant Ongoing
General
80 Digester Deep Structure Y 5 5 25 High - 0 25 HighNo life buoy or safety ropes in a very deep
structure
Provide life buoys and safety
ropes for structureC Morkel & R Brown & Consultant 2013
General
81 Incinerators Incinerators very old Y 4 4 16 Medium - 0 16 MediumThe incinerators are very old and parts have
become hard to source
Upgrade of the incinerators must
be investigated as part of future
upgrade
C Morkel & R Brown & Consultant 2016
Process Failure
84 Maturation Ponds Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 4 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Pri
ma
ry G
as
Dig
est
ers
Se
con
da
ry G
as
Dig
est
er
Inci
ne
rato
rsM
atu
rati
on
Po
nd
s
Pa
arl
WW
TW
Act
iva
ted
Slu
dg
e R
ea
cto
rC
lari
fie
rs
Pa
arl
WW
TW
Me
tha
ne
Ta
nk
s
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Pa
arl
WW
TW Do
me
stic
Pu
mp
ing
Sta
tio
nIn
let
Wo
rks
Pa
arl
WW
TW
Pri
ma
ry S
ett
lin
g T
an
ks
Bio
filt
ers
Hu
mu
s T
an
ks
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Electrical Failure
85 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumWarning lights checked daily, with Reactive
Maintenance and Standby Generator on Site100 0 None Weekly inspection of Component
C Morkel
C PaulseOngoing
86 Chlorination Store Room Dosing Electronics Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low Weekly inspection of Component
C Morkel
C PaulseOngoing
Process Failure
89 Chlorination Channel Compliance Monitoring Y 5 5 25 High24h Compliance Monitoring with on site lab.
Newly refurbished90 2.5 Low
Compliance Monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C Paulse & R BrownOngoing
Electrical Failure
91 Transformer Transformers on site (4 No) Y 5 5 25 HighOperation and Maintenance from
Drakenstein Electrical Department0 25 High
Drakenstein Electrical Department is laboring
under capacity constraints and maintenance
cannot always be effected in time
Maintenance schedule for all
transformers which MUST be
adhered to and additional staffing
in the Electrical Department
D du Plessis Ongoing
92
Ge
nse
t
Genset Switch Over Board Y 4 5 20 Medium - 0 20 MediumThe existing switch board is old and is in need of
upgrading with new switchgear, etc.
Investigate upgrading of switch
board as part of future upgrade of
works
C Morkel & R Brown & Consultant 2016
General
94 General Site Lighting Y 3 5 15 Medium Existing high mast lighting 50 7.5 LowInvestigate additional high mast
lighting when requiredC Morkel & R Brown & Consultant 2016
95 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown & Consultant 2013 R 700 k
Paarl
WWTW
Ele
ctri
cal
Tra
nsf
orm
er
Ge
ne
ral
Ch
lori
na
tio
n
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
33 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low
An audit has been performed and corrective
measures have been identified.Weekly inspection of Component
M Krautz
C Paulse & R Brown
Ongoing &
End 2012 for
Corrective
Measures
34 Chlorination Store Room Dosing Electronics Y 4 6 24 MediumReactive Maintenance and Standby
Generator on Site80 4.8 Low
An audit has been performed and corrective
measures have been identified.Weekly inspection of Component
M Krautz
C Paulse
Ongoing &
End 2012 for
Corrective
Measures
Process Failure
38 Maturation Ponds Compliance Monitoring Y 5 5 25 High
Compliance Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott) and Maturation Pond
Maintenance
80 5 Low
Compliance monitoring to occur to alert levels
with corrective actions as per Alert Level, Algal
problems occurred in retention pond and
retention time was reduced, however sediment
transport remains problematic
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
M Krautz
C PaulseOngoing
Electrical Failure
42 Pumping Station Power failure Y 5 4 20 Medium Standby generator on site & Overflow pond 90 2 Low -
Pro-Active Maintenance Required
& servicing of standby generator
required
M Krautz & R Brown Ongoing
43 Pumping Station Telemetry Y 4 5 20 Medium - 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
Mechanical Failure
44 Sludge Drying Beds Drainage Pump Y 4 4 16 Medium Reactive Maintenance 100 0 None New Pump Currently sourced
Monitor supplier performance
and pump performance after
commissioning
R Brown 2012
General
45 General Security at works Y 4 6 24 Medium - 0 24 Medium No Security on site
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
46 General Office Facilities Y 5 6 30 High - 0 30 High No office on site. Non-Compliance with OSH ActProvide office facilities as part of
the future upgradeR Brown & Consultant 2016
Pe
arl
Va
lle
y W
WT
W
Se
wa
ge
Pu
mp
ing
Sta
tio
nS
lud
ge
Dry
ing
Be
ds
Ge
ne
ral
Pe
arl
Va
lle
y W
WT
W
Ch
lori
na
tio
nM
atu
rati
on
Po
nd
s
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PEARL VALLEY WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Pumping Station Power failure Y 5 5 25 High - 0 25 High
No Standby Generator on site, Urgently required
as this is the closest pumping station to the Berg
River
Provide standby Generator to site R Brown & Consultant End 2013
Process Failure
2 Pumping Station Flow meter Y 3 5 15 Medium - 0 15 Medium Flow meter has not been commissioned Commission Flow meter R Brown & Consultant End 2013
Mechanical Failure
3 Pumping Station Screening of Sewage Y 4 5 20 MediumBasket screen, inspected daily according to
pumping station checklist90 2 Low -
Ensure inspections occur regularly
with cleaning as requiredD Claasens Ongoing
General
6 Pumping Station No permanent supervision Y 5 5 25 High Daily inspections only 0 25 HighSupervision required as pumping station is closest
to Berg River
Investigate need for permanent
supervision on site or telemetry
system
R Brown & Consultant 2014
General
11 Pumping Station Security Y 5 5 25 High3m high wall with barbed wire, fencing,
security lights and Armed response80 5 Low
High vandalism rate at this pumping station forced
extreme security measures
Investigate inclusion of site into
perimeter of new fence around
WWTW and Land fill site
R Brown & Consultant 2014
General
12 Pumping Station Design Capacity Exceedance Y 3 5 15 Medium - 0 15 Medium Capacity problems observed in past
Investigate capacity requirement
of this pumping station (currently
T3 pumps installed)
R Brown & Consultant 2014
Mechanical Failure
14 Pumping Station Screening of Sewage Y 3 5 15 Medium - 0 15 MediumContract has been issued for provision of a
mechanical screen
Monitor contractor performance
and Mechanical Screen
performance after commissioning
R Brown & Consultant & D
ClaasensOngoing
General
17 Pumping Station Security Y 5 5 25 High Broken fencing and Armed response 25 18.75 MediumHigh vandalism rate at this pumping station
requires security measures
Investigate construction of new
fencing and possibly alarm systemR Brown & Consultant 2014
18 Pumping Station Telemetry at pumping Station Y 3 5 15 Medium - 0 15 Medium
Telemetry required as pumping station is closest
to Berg River, Contractor appointed to upgrade
entire telemetry network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
General
21 General Plant Design Capacity Exceedance Y 5 5 25 High 0 25 HighUpgrading of Plant Required, All flows pumped to
WWTW therefor also may need a balancing dam
Upgrade entire Plant and
investigate the construction of
balancing dam to balance flows
from all the pumping stations
D Claasens & R Brown &
Consultants2016
Electrical Failure
22 Inlet Works Power failure Y 5 5 25 High No Standby Generator on site - 0 25 High No Standby Generator on SiteInstall Standby Generator as part
of upgrade
D Claasens & R Brown &
Consultants2016
Process Failure
26 Inlet Works Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 80 4 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
D Claasens
C PaulseOngoing
Process Failure
31 PST's Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 80 3.2 LowOperational monitoring needed with Actions as
per Alert LevelFollow Alert Level actions
D Claasens
C PaulseOngoing
Process Failure
37 Biofilters Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 3.2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
Process Failure
43 Humus Tanks Operational Monitoring Y 4 4 16 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 3.2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
Process Failure
55 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 4 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
D Claasens & C Paulse & R Brown Ongoing
Process Failure
59 Clarifier Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 4 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
Electrical Failure
66 Chlorination Store Room Warning Lights outside building Y 5 5 25 High
Reactive Maintenance and No Standby
Generator on Site, Inspection completed
and Certificate for compliance obtained
90 2.5 Low A Standby Generator on site is imperative
Weekly inspection of Component
and installation of Standby
Generator on site
D Claasens
C Paulse & R Brown & Consultants2015
67 Chlorination Store Room Dosing Electronics Y 5 5 25 High
Reactive Maintenance and No Standby
Generator on Site, Inspection completed
and Certificate for compliance obtained
90 2.5 Low A Standby Generator on site is imperative
Weekly inspection of Component
and installation of Standby
Generator on site
D Claasens
C Paulse & R Brown & Consultants2015
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
We
llin
gto
n W
WT
W
Industrial Park
Sewage
Pumping
Station
(Pacmar)
Newton
Sewage
Pumping
Station
Erf 8000
Sewage
Pumping
Station
We
llin
gto
n W
WT
W
Inle
t W
ork
sP
rim
ary
Se
ttli
ng
Ta
nk
sB
iofi
lte
rsC
hlo
rin
ati
on
We
llin
gto
n W
WT
W
Hu
mu
s T
an
ks
Act
iva
ted
Slu
dg
e R
ea
cto
r
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Process Failure
70 Maturation Ponds Compliance Monitoring Y 5 5 25 High
Compliance Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
80 5 LowCompliance monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
D Claasens
C PaulseOngoing
General
71 Sludge Drying Beds Design Capacity Exceedance Y 5 5 25 High - 0 25 High2 Waste ponds, Large Sludge Volume coming into
works.
Investigate sludge handling (e.g.
Dewatering Plant) as part of
future upgrade of works
D Claasens & R Brown &
Consultants2016
General
72 Digester No Gas Tank Y 4 5 20 Medium - 0 20 Medium
The plant has Gas Digesters but no gas tank. A
waste to energy project has been initiated which
could utilize the gas
Investigate gas storage or
conveyance to waste to energy
site as part of future upgrade of
works
D Claasens & R Brown &
Consultants2016
General
73 Incinerator No incinerator on site for screenings Y 4 5 20 MediumScreenings conveyed to Paarl WWTW for
Incineration50 10 Low -
Investigate on site incinerators or
conveyance to waste to energy
site as part of future upgrade of
works
D Claasens & R Brown &
Consultants2016
General
74 Personnel Facilities Offices Y 4 5 20 MediumSome office space provided with limited
ablution facilities10 18 Medium Existing facilities do not comply with OSH Act
Investigate the construction of a
new office building with ablution
facilities all to comply with the
OSH Act as part of future upgrade
of works
D Claasens & R Brown &
Consultants2016
75 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013
76 General Site Lighting Y 5 4 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient
Investigate the new or additional
high mast site lighting as part of
future upgrade of works
D Claasens & R Brown &
Consultants2016
77 General Security Y 5 5 25 High Existing Fence 25 18.75 MediumContract for a new security fence has been issued
and is underway
Monitor contractor performance
and maintain new fence after
commissioning
D Claasens & R Brown &
ConsultantsEnd 2012
78 General Signage Y 5 5 25 High - 0 25 HighSignage is required on site to comply with various
statutory regulations including the OSH Act
Investigate provision signage as
part of future upgradeR Brown & Consultant End 2013
We
llin
gto
n W
WT
W
Ma
tura
tio
n
Po
nd
s
Slu
dg
e D
ryin
g
Be
ds
Ga
s D
ige
ste
rIn
cin
era
tor
Ge
ne
ral
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Process Failure
1 Inlet Influent compliance Y 4 5 20 MediumOperational monitoring i.e. Laboratory
testing- 80 4 Low
Operational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
C Morkel
C PaulseOngoing
Process Failure
6 Evaporation pond 3 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
Investigate need for Mini Lab. On
site
C Morkel
C Paulse & R BrownOngoing
7 Evaporation Ponds Ground Water Monitoring Wells Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
C Morkel
C PaulseOngoing
Structural Failure
8 Sump Structure Sump Structure Size Y 3 5 15 MediumDaily inspection of sump according to
Pumping Station checklist25 11.25 Low
Current sump structure to large and has overflow
walls and no Mechanical screen. Screenings
accumulate in first chamber and must be manually
removed
Investigate upgrade of pumping
station and installation of
Mechanical Screen
R Brown & Consultants 2017
Mechanical Failure
9 Pumps Pump Failure Y 3 5 15 MediumReactive maintenance with 24h turn around
time50 7.5 Low
Pumps may experience problems due to
screenings clogging the pumps
In the interm continue daily
inspections and Investigate
upgrade of pumping station and
installation of Mechanical Screen
in future
C Morkel & R Brown &
Consultants
Ongoing &
2017
Electrical Failure
10 Pumps No Standby Power Y 5 5 25 High - 0 25 HighAt the moment no Standby Power at the pumping
station
Investigate supply of standby
power generator at pumping
station
C Morkel & R Brown &
Consultants2017
General
11 General Telemetry at Pumping Station Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : HERMON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
He
rmo
n W
WT
W
Inle
tE
va
po
rati
on
Po
nd
sH
erm
on
Se
wa
ge
Pu
mp
ing
Sta
tio
n
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
1 Inlet Works Power failure Y 5 5 25 High No Standby generator on site - 0 25 High No Standby Generator on site
Install Standby Generator as part
of WWTW upgrade. Contractor
appointed and supply of
generator imminent
T Simons & R Brown & Consultant End 2012 R 350 k
Mechanical Failure
4 Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day70 4.5 Low
Permanently posted staff clean hand raked screen
and a new Mechanical screen will be provided at
the Saron Sewage pumping station in new
contract
Monitor screenings amount after
commissioning of mechanical
screen at Saron Sewage pumping
station
T Simons & R Brown & ConsultantsEnd 2012
and OngoingN/A
Process Failure
6 Inlet Works Influent compliance Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
- 90 2 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
T Simons
C PaulseOngoing
7 Inlet Works Design Capacity N 4 5 20 Medium 0 20 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Structural Failure
8 Inlet Works Inlet Works Structure Y 3 5 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Electrical Failure
9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h
turn around time
Replaced Mixer and now Pro-
Active Maintenance and ServicingT Simons & C Morkel & R Brown Ongoing
Mechanical Failure
10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h
turn around time
Replaced Mixer and now Pro-
Active Maintenance and ServicingT Simons & C Morkel & R Brown Ongoing
Structural Failure
11 Anaerobic Zone Zone Structure Y 4 4 16 Medium 0 16 MediumNew Reactor must be constructed as part of
WWTW upgrade
Construct new Reactor as part of
WWTW upgradeT Simons & R Brown & Consultant 2014
Electrical Failure
12 Aerobic Zone Aerator Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h
turn around time
Hour Logging, Pro-Active
Maintenance and Servicing or
possible standby Aerator. Also
investigate timer for low flow
periods
T Simons & Process Controllers &
R BrownOngoing
Mechanical Failure
13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h
turn around time
Hour Logging, Pro-Active
Maintenance and Servicing or
possible standby Aerator. Also
investigate timer for low flow
periods
T Simons & Process Controllers &
R BrownOngoing
Process Failure
14 Aerobic Zone Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
90 2 LowOperational Monitoring to determine sludge
wasting
Operational Monitoring as
scheduled with process
adjustments at alert levels as
necessary
T Simons & C Paulse & R Brown Ongoing
Structural Failure
17 Clarifier Clarifier Structure Y 3 5 15 Medium Inspection of Structure 0 15 MediumInspection must occur during cleaning, Cracks
observed on outside.
Inspect structure during cleaning,
perform structural investigation
with report
T Simons & C Morkel & R Brown &
Consultants2016
Process Failure
18 Clarifier Operational Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
T Simons
C PaulseOngoing
Mechanical Failure
20 Pumping Station Pumps Y 5 5 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump
Investigate installation of standby
pump in sum as part of future
upgrade
T Simons & C Morkel & R Brown &
Consultants2016
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : SARON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Sa
ron
WW
TW
Inle
t W
ork
sA
ctiv
ate
d S
lud
ge
Re
act
or
Cla
rifi
er
Re
cycl
e &
Wa
ste
Slu
dg
e
Pu
mp
ing
Sta
tio
n
DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness
(%)
Comment Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : SARON WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Electrical Failure
22 Chlorination Store Room Warning Lights outside building Y 5 5 25 HighReactive Maintenance and No Standby
Generator on Site50 12.5 Low
Entire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
23 Chlorination Store Room Dosing Electronics Y 5 5 25 HighReactive Maintenance and No Standby
Generator on Site50 12.5 Low
Entire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
Structural Failure
24 Chlorination Store Room Store Room Structure Y 5 5 25 High Inspection of Structure 50 12.5 LowEntire system will be replaced with Chlorine tablet
system until future upgrade is completed
Coordinate a new disinfection
system with future upgrade of
works
T Simons & R Brown & Consultant 2016
Structural Failure
25 Maturation Ponds Structures across river Y 4 4 16 Medium 0 16 Medium
Structure across river may have leakages in
crossing, relining of 1st pond currently (2012)
underway
Construct new Maturation ponds
closer to the WWTW as part of
upgrading of WWTW
T Simons & R Brown & Consultant 2016
Process Failure
26 Maturation Ponds Compliance Monitoring Y 4 5 20 Medium
Operational Monitoring through on site Mini
Lab., weekly verification at Paarl WWTW
lab. and Monthly Audit by Independent Lab.
(A.L. Abbott)
90 2 LowCompliance monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed
T Simons
C PaulseOngoing
Structural Failure
27 Sludge Drying Beds Bed Structures Y 4 6 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished T Simons & R Brown & Consultant 2016
Process Failure
28 Sludge Drying Beds Filter Medium Y 5 3 15 Medium 0 15 MediumWater does not filter through quick enough,
Contractor appointed to refurbish the beds
All beds to be refurbished,
monitor speed of water filtration
after refurbishments are complete
T Simons & R Brown & Consultant 2016
General
29 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
30 General Security Guard at works Y 5 4 20 Medium 0 20 Medium No security guard at the works.
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
31 General Site Lighting Y 5 4 20 Medium 0 20 Medium Minimal site lightingAdditional site lighting must be
provided as part of future upgradeR Brown & Consultant 2016
Sa
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DATE : 29-Jun-12 Rev B
Item no Area Location System Hazard/Risk DescriptionCould this issue
result in a risk?Likelihood Consequence Existing controls Control reference
Control
Effectiveness (%)Comment
Recommended mitigation/ improvement
planResponsibility Deadline Budget Signature
Electrical Failure
2 Pumping Station Standby power Y 5 5 25 High - 0 25 High No Standby Power generator available on site
A standby power generator must
be provided for the pumping
station
R Brown 2016
Process Failure
4 Inlet Influent compliance Y 4 5 20 Medium
Operational monitoring through weekly
testing as there no effluent outflow from
this evaporation pond system
- 90 2 LowOperational monitoring is to occur to operational
monitoring alert level
Ensure monitoring occurs as
scheduled
R Jacobs
C PaulseOngoing
Mechanical Failure
5 Inlet Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout
the day90 1.5 None
Permanently posted staff clean hand raked screen,
however low screenings volume due to mechnical
screen at Gouda Sewage Pumping Station
Clean Screen Daily R Jacobs Ongoing
Process Failure
1 Inlet Spetic tank influent compliance Y 4 5 20 Medium - - 0 20 MediumNo monitoring of farms septic tank loadings (e.g.
COD, etc.)
Sampling of farm septic tanks
inffluent must be performed to
gauge impact on process
R Jacobs & C Paulse & R Brown Ongoing
Process Failure
10 Primary Pond 1 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
11 Primary Pond 2 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
12 Secondary Pond 3 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
13 Secondary Pond 4 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
14 Secondary Pond 5 Operational Monitoring Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
15 Secondary Pond 6 Compliance Monitoring Y 5 5 25 High
Compliance Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2.5 LowCompliance monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
16 Evaporation Ponds Ground Water Monitoring Wells Y 4 5 20 Medium
Operational Monitoring weekly sampling
with monthly audits by independent lab.
(A.L. Abbott)
90 2 LowOperational monitoring to occur to alert levels
with corrective actions as per Alert Level
Ensure Monitoring occurs as
scheduled and incident
management protocol is followed,
investigate feasibility of Mini lab.
On site
C Morkel
C PaulseOngoing
General
17 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry
network
Monitor contractor performance
and telemetry performance after
commissioning
R Brown 2013 R 700 k
18 General Security Guard at works Y 5 4 20 Medium 0 20 Medium No security guard at the works.
Provide security guard and
facilities as part of the future
upgrade
R Brown & Consultant 2016
19 General Site Lighting Y 5 4 20 Medium 0 20 Medium Minimal site lightingAdditional site lighting must be
provided as part of future upgradeR Brown & Consultant 2016
HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : GOUDA WWTW
Inherent Risk Score (before
consideration of any controls)Residual Risk Score
Go
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