Dungarvan Waste Water Treatment Plant · 2014. 12. 16. · Wastewater treatment plant....

Dungarvan Waste Water Treatment Plant

Annual Environmental Report for Year 2010

February 2011

Waterford County Council

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Dungarvan WWTP.doc 28 January 2010

Dungarvan Waste Water Treatment Plant

Annual Environmental Report for Year 2010

February 2011


Issued By: Water Services Section,

Date March 28th 2011

Originator J O Sullivan, SEE _________________ _______________

Approver M Quinn, DOS _________________ _________________

Checker N/A

Revision Description Date

Issue and revision record

Chapter Title Page

Executive Summary i

1. Introduction 1

1.1 Licence register number ______________________________________________________________ 1 1.2 Name ____________________________________________________________________________ 1 1.3 Site location _______________________________________________________________________ 1 1.4 Description of activities at the site _______________________________________________________ 1 1.5 Company environmental policy (where available) ___________________________________________ 1 1.6 Company organisation chart for Environmental Management _________________________________ 2

2. Summary Information 3

2.1 Self-Monitoring Data (summary) ________________________________________________________ 3 2.1.1 Emissions to waters/sewer ____________________________________________________________ 3 2.1.2 Waste Arisings _____________________________________________ Error! Bookmark not defined. 2.2 Agency Monitoring and Enforcement ____________________________________________________ 5 2.3 Energy and Water Consumption ________________________________________________________ 6 2.3.1 Energy Consumption ________________________________________________________________ 6 2.3.2 Water Consumption _________________________________________________________________ 6 2.4 Environmental Incidents and Complaints _________________________________________________ 6 2.5 AER Summary Data Table ____________________________________________________________ 7

3. Management of the Activity 8

3.1 Improvement Programme Report _______________________________________________________ 8 3.2 Pollution Emission Register ___________________________________________________________ 9

4. Licence-Specific Reports 11

4.1 Summary Report on Monthly Influent Monitoring __________________________________________ 11 4.2 Data Collection and Reporting Requirements under the Urban Wastewater Treatment Directive _____ 12 4.3 Storm Water Overflow Identification and Inspection Report __________________________________ 12 4.4 Development/Infrastructural Works Summary (completed for previous year or prepared for current

year) ____________________________________________________________________________ 13 4.5 Summary Report on Ambient Water Quality of Colligan Estuary and Dungarvan Harbour, pursuant to

the requirements of the Shellfish Directive (2006/113/EC) ___________________________________ 14

5. Environmental Liabilities 16

5.1 Annual Statement __________________________________________________________________ 16 5.2 Environmental Liabilities Risk Assessment _______________________________________________ 16

Content

i

Dungarvan Town is located on the estuary of the Colligan River and has a population of

circa 9000 persons as well as commercial activity. There are no wet industries, with the

main industries being pharmaceutical processing.

Dungarvan and environs has a new sewerage scheme, with a treatment plant

located at Ballinacourty, which is operational since 2007. Wastewater is collected in a

number of catchments in Dungarvan and is pumped from these catchments to a main

pumpstation in Shandon from where it is pumped to the new waste water treatment plant

in Ballinacourty. Waste water is delivered to Ballinacourty via two rising mains of over

6km length each. Each pumpstation in the network has stormwater overflow facilities

which operate in storm conditions, when the forward pumping capacity of the stations is

exceeded.

The treatment plant at Ballinacourty has performed up to standard and all effluent

from the plant complied with the licence limits during 2010.

Executive Summary

1

1.1 Licence register number

D0017-01

1.2 Name

Dungarvan Agglomeration and Waste Water Treatment Plant

1.3 Site location

Wastewater treatment plant.

Ballinacourty, Dungarvan, Co. Waterford

230500E, 092150N

1.4 Description of activities at the site

The Dungarvan Waste Water Treatment Plant located at Ballinacourty, commenced operation in July

2007 and is designed to serve a population equivalent of 25,000. The plant was procured under a

DBO contract and the management of the facility is contracted to Veolia Water by Waterford County

Council.

The Ballinacourty Waste Water Treatment Plant treats domestic, commercial and industrial effluent

from Dungarvan Town and the Ballinacourty and Clonea catchment areas. Wastewater is transferred

to the plant via twin rising mains from Shandon Pumping Station in Dungarvan Town and via a single

rising main from the Ballinacourty and Clonea areas. Waste water in the Ballinroad area will be

conveyed to Ballinacourty WwTP by 1st November 2011 as stipulated in the waste water discharge

licence of 2009. The existing secondary treatment plant at Ballinroad will then be decommissioned.

Primary and Secondary treatment of waste water at Ballinacourty is achieved by screening and grit

removal at the inlet works, settlement, secondary biological treatment (activated sludge), clarification

and sludge removal. Sludge undergoes dewatering and thermal drying on site to produce a final

product which meets the requirements for use in agriculture. The treatment plant is designed to treat

sludge for a population equivalent of approximately 75,000. This figure accommodates sludges

imported for treatment, which includes dewatered, belt pressed, aerobic and septic tank sludges.

The primary discharge (SW1) from Ballinacourty WwTP is via an outfall pipe and diffuser into the

outskirts of Dungarvan Harbour, off Ballinacourty Point. The secondary discharge point (SW20) from

the Ballinroad WwTP into the Colligan Estuary. This discharge will be discontinued by the 1st

November 2011.

1.5 Company environmental policy (where available)

Waterford County Council is committed to environmental protection and improvement as part of it‟s

role in Local Government and it‟s statutory obligations. It does not have a specific environmental

1. Introduction

2

policy as all such policies are included in the Councils Strategic plan, but not in a format suitable for

extract to this document.

1.6 Company organisation chart for Environmental Management

The above structure was developed in 2010. Waterford County Council has divided the

Water Services Operations & Maintenance Team into three relevant individual teams

namely, the Waste Water Team, the Pollution Control and River Basin District Team

and the Drinking Water Quality & Supply Team.

All of the above listed team members have duties in other areas of work under the umbrella

of Water Services Operations & Maintenance.

Michael Quinn

Director of Services

Transportation and

Infrastructure

Pat McCarthy

Senior Engineer

Water Service Operations

& Maintenance

Waste Water

Operation and

Maintenance

Pollution Control

Team

Administrative Staff

Mary

Hayes

Vacant

Declan

Halpin

Tech. Grade

2

John O’Sullivan

Senior Executive

Engineer

Conor Foley

Senior Executive

Engineer

Tim Bourke

Senior

Executive

Technician

Paul Carroll Executive

Scientist

Drinking Water

Quality & Supply

Team

Organisational Structure.

Water Services Staff Structure:

Water Quality, Pollution & Drinking Water

Pollution

Control and

River Basin

District Team

Jimmy Mansfield

Senior Executive

Engineer

Thomas

Butler

Technician

Grade 1

Susan Cook

Technician

Grade 2

3

2.1 Self-Monitoring Data (summary)

2.1.1 Emissions to waters/sewer

This section details the emissions to water from Ballincourty WWTP over the period January 2010 –

December 2010.

Summary Table for Emissions to Waters

Licensed ELVs % compliance

Flow (m3/d)

pH 6.0-9.5 100

cBOD (mg/l) 25 100

COD (mg/l) 125 100

SS (mg/l) 35 100

Ammonia 10 100

TON 10 100

COD mg/l

BOD mg/l SS mg/l

Inlet Total

Nitrogen mg/l

Inlet Total Phosphorous

mg/l

Total Oxidised Nitrogen

mg/l Ammonia

mg/l

Total Phosphorous

mg/l

Orthophosphate mg/l date

24/01/2010 16 3 <5 9 1.508 7.323 0.5

14/02/2010 48 3 15 11.4 1.111 7.843 0.3

21/03/2010 47 <4 16 14.9 2.15 3.9 0.9 1.2 1.13

18/04/2010 39 <4 7 14.6 2.02 8.2 0.3 1.31 1.26

16/05/2010 48 <4 8 16.5 2.1 5.7 1.5 1.53 1.44

15/06/2010 53 3 23 17.5 2.2 8.4 0.1 1.88 1.81

20/07/2010 25 2 14 18.1 2.62 9.6 0.1 2.13 2.03

15/08/2010 62 <2 11 38.2 4.94 7.9 0.1 2.52 2.47

19/09/2010 36 2 18 12 1.68 9 0.1 1.98 1.88

17/10/2010 31 <2 13 24.4 3.38 9.1 <0.1 1.77 1.74

21/11/2010 24 4 <5 17.9 2.35 6.8 3.5 1.76 1.67

09/12/2010 40 <2 <5 19.2 2.71 4.6 7 1.55 1.46

2. Summary Information

4

Date Faecal

Coliforms MPN/100mls

Escherichia Coli

MPN/100mls

Intestinal Enterococci CFU/100mls month

average flow m3/d

Jan-10 10,905

Feb-10 8,570

21/03/2010 11000 2420 340 Mar-10 7,761

18/04/2010 11000 11240 280 Apr-10 7,784

16/05/2010 4600 8664 180 May-10 7,842

15/06/2010 11000 7380 184 Jun-10 7,133

20/07/2010 11000 2460 400 Jul-10 5,245

15/08/2010 4600 2420 182 Aug-10 4,202

19/09/2010 110,000 111,990 340 Sep-10 5,051

17/10/2010 46000 5910 320 Oct-10 5,332

21/11/2010 1100000 241960 24,000 Nov-10 4,414

19/12/2010 110000 68670 888 Dec-10 3,005

Source: Contract operator PMS reports.

The monitoring data presented above is the final effluent from the Ballinacourty WWTP

Licensed parameters i.e. Total Oxidised Nitrogen, Ammonia, Total Phosphorus and Orthophosphate

are included in the monitoring programme (under Schedule B of the Licence) and missing some early

in year results. Licence issue was mid Dec 2009. Metals and Organic Compounds not analyses on

effluent due to samples lost by contract laboratory arranged by Waterford Co.Co.. Faecal Coliforms,

Escherichia coli and Intestinal enterococci were monitored monthly from March 2010

Summary of Non-compliances, Dungarvan WWTP

Date Non-compliance Cause Corrective Action

N/A 0 0 0

Text Left Right Right Right

Source: PMS reports from Operator Veolia.

Ballinroad WWTP

Ballinroad WWTP, secondary discharge SW20, EFFLUENT analysis.

Date of Sampling

Sample Type

BOD mg/l

COD mg/l

TSS mg/l

Ortho P mg/l P

NH3-N mg/l N

TON mg/l N

26-Feb-10 Grab 372 500 72 3.42 5.42 0.2

28-May-10 Grab 217 373 119 2.29 34.34 0.2

03-Sep-10 Grab 341 643 188 7.36 34.14 0.2

12-Oct-10 Grab 341 579 118 7.39 57.46 0.2

10-Dec-10 Grab 350 575 68 7.22 43.07 0.62

17-Dec-10 Grab 371 563 140 7.71 62.48 0.2

5

Summary of Non-compliances, Ballinroad WWTP

Date Non-compliance Cause Corrective Action

All All Plant not working/overload

De commission, Pump effluent to Dungarvan,

due for Nov.2011

2.1.2 Waste Arisings

Year Description No of bins Destination

2010 Grit &

Screenings

53 x 240L

Greenstar Ltd.,Carrignard, Six Cross Road, Waterford.

59 x 660L

82x 1100L

Total m3 waste

141.86

Year Description Quantity, Tonnes Dry

solids

Destination

2010 Dewatered sludge 23.21 Ormande Organics,

Portlaw

2010 Dewatered sludge =

some dried pellet

296.63** SEDE, Derrylea,

Portarlington

** The tonnage is that of processed sludge that leaves the Dungarvan Plant. The PRTR shows only

150 tonnes as this is representative of the sludge from the sewage treatment process of Dungarvan

only. The balance of sludge arisings is from outside origin sludges that pass through the plant for

processing.

2.2 Agency Monitoring and Enforcement

No entries this section by Waterford Co Council.

Details of:

Emissions sampling and analysis by Agency laboratory staff

Site visits and inspections carried out by Agency Inspector

Detailed audit of facility carried out by Agency personnel

Highlight any significant differences between their monitoring data and that of the Agency

6

2.3 Energy and Water Consumption

2.3.1 Energy Consumption

Energy Consumption Summary

Energy Supply quantity units

Heavy fuel oil nil

Light fuel oil 21746 litres

Natural Gas nil

Electricity 551,579 kWhr

Coal, etc.

Source: Operator PMS reports

2.3.2 Water Consumption

Water Consumption Summary. Annual volume.

Water Source Volume (m3)

On-site ground water nil

On-site surface water nil

Municipal supply 4014

2.4 Environmental Incidents and Complaints

Incident: Pumpstation failure Dec 2010 at Shandon Dungarvan.

Reported to EPA, as incident in Dec 2010.

Section 6.1 of the licence states that:

“The licensee, shall notify the Agency by both telephone and facsimile, to the Agency’s headquarters in Wexford, or to such

other Agency office as may be specified by the Agency, as soon as practicable after the occurrence of any incident (as defined

in this licence). The licensee shall include as part of the notification, date and time of the incident, summary details of the

occurrence, and where available, the steps taken to minimise any discharges.”

7

2.5 AER Summary Data Table

The following pages contain tables as extracted from the PRTR returns. On the electronic pdf version

of this AER, the tables are at the end of the report.

8

Management of the Activity

2.6 Improvement Programme Report

Report on progress made and proposals being developed to meet the improvement programme

requirements namely those set out in Schedule C of the licence. This summary report shall provide

detail on all measures proposed and undertaken under Water Services Investment Programme for

agglomeration, including progress reports on infrastructural works and a statement of compliance with

timeframes set out in this licence.

Schedule C of the licence - C.2 Improvement Programme for Secondary Discharge

Specified Improvement: Implement a programme of works to ensure SW2 and SW3 only discharge

in the event of an emergency, that is, during pump failure and/or power failure at the associated

pumping station.

Report: SW2 is the storm overflow from Shandon Pump Station. Dungarvan sewerage scheme

comprises a number of sub catchments each delivering to individual pumpstations, from where a

multiple of Dry Weather flow is pumped forward in the network until the waste water arrives at

Shandon Pumpstation. Each pumpstation has an overflow facility that is reached when Rainfall

invades the network and forward flows are at their limit. These pumpstations act as storm water

overflow facilities. Shandon pump station has its own contributing catchment as well as the pumped

inputs from the other peripheral stations.

SW2 is the main pump station pumping to the Waste water treatment plant. Its pumping capacity, via

two rising mains is 650m3 per hour to the plant. Any flows into the station in excess of this are

overflowed via a screen to a storm well and subsequently discharged by pumping to the Colligan

Estuary.

This discharge would comply with Formula A discharges to non sensitive areas according to

DoEHLG „Procedures and Criteria in relation to Storm Water Overflows, 1995’. Using a population of

9000 a domestic contribution of 225litres/day and a industrial loading of 400m3 per day, Formula A

flows are calculated as 9000x0.225 + 1.36x9000+2x400 = 15,065m3/day = 627m3/hr. This is less

than the 650m3 pumping capacity.

Discharge at SW3 : This discharge is also a storm water overflow. The pump station is designed to

pump forward multiple times the dry weather flow. The capacity of the pumps is up to 230m3 hour

forward via the network to Shandon station. The contributing catchment population is not calculated

so the compliance of the Storm overflow threshold against formula A flows is not available. Given the

design philosophy adopted for this new station, it is quite likely compliant, as the design was carried

out using a computer simulation model.

Discontinuation of SW2 and SW3: Both these discharge points are storm overflows as well as

pumpstations. Elimination of these discharges will require a complete re-design of the collection

system, the pump stations and the Waste water treatment plant. The nature and extent of the work

involved could not be implemented by the local authority under its own finances and would have to be

put forward under the WSIP (Water Services Investment Programme). The current WSIP programme

is 2010 to 2012 and the required works for planning are not in this programme. The next programme

would hopefully be 2012 to 2014 and the design/ planning can be put forward for this programme as a

proposal, when a call for proposals is received from the DoEHLG. The following process will have to

be followed:

9

1: The scheme has to be put into the assessment of needs of the Local Authority, the current

assessment is 2009. There is a possibility that a review of the current assessment or a call for a

revised assessment under specified national criteria would happen in 2011. This would be a request

from the DoEHLG. It is also possible that a review of the WSIP programme would be called for in

2011 and if so the scheme can be proposed for acceptance to the WSIP.

1: An extensive design and modelling of the network must be carried out to evaluate the performance

of the storm overflows and to then agree with the Agency as to the appropriate direction to take. This

design/ planning has to be carried out as a scheme “under planning” under the Water Services

Investment Programme (WSIP), due to the task size of design and the implications for works.

2: If the scheme is deemed to require from the planning stage to stop discharges at SW2 and SW3,

the whole of Dungarvan Sewerage scheme has to go forward for Planning and design and this will

include the New Waste water treatment plant. A similar and smaller agglomeration of Tramore is

currently at planning stage for network improvements, including reducing Storm water overflows. This

scheme is currently estimated to cost €11m. Given the larger network of Dungarvan and its layout, the

likely costs of such measures would exceed €20m.

Refer to Condition 5.6. Completion date – 1st

November 2011.

Any other overflows notified in writing by the Agency. Completion date – as agreed.

No notifications under this category

Schedule C of the licence - C.3 Improvement Programme for Storm Water Overflows

Specified Improvement:

Upgrading of sewer network, as required to ensure Storm Water Overflows comply with the criteria

outlined in the DoEHLG „Procedures and Criteria in relation to Storm Water Overflows, 1995’ Refer to

Condition 4.13. Completion date – 1st

November 2011.

Reply: The network upgrade required under this condition is the same exercise as required for the

elimination of SW2 and SW3 and the process is outlined above.

Any other overflows notified in writing by the Agency. Completion date – as agreed.

No notifications under this category

2.7 Pollution Emission Register

4.13 The licensee shall prepare a PRTR report for the primary and secondary discharges. The

substances to be included in the PRTR shall be as agreed by the Agency each year by reference to

EC Regulation No. 166/2006 concerning the establishment of the European Pollutant and Transfer

Register and amending Council Directives 91/689/EEC and 96/61/EC. The PRTR shall be prepared in

accordance with any relevant guidelines issued by the Agency and shall be submitted electronically in

specified format and as part of the AER.

10

PRTR reporting by electronic transfer. Priority and hazardous substances have been estimated by the

use of EPA calculation tool. Waterford county council sampled the effluents from their plants in 2010

for the purpose of evaluating the level of substances discharged, but were left down due to the

contracting laboratory losing the samples. Hence use of EPA calculation tool.

11

3.1 Summary Report on Monthly Influent Monitoring

4.15 The licensee shall carry out monthly monitoring of the influent stream to the waste water

treatment plant for cBOD, COD, Suspended Solids, Total Nitrogen and Total Phosphorus in order to

measure the mass loadings and removal efficiencies within the treatment plant.

Tables below show the mass loading against the measured parameters. Table 1 is the incoming

loading. Table 2 is the treated effluent discharge along with the removal efficiency achieved for each

parameter.

Table 1 Dungarvan WWTP Influent loadings

COD Kgs BOD Kgs SS Kgs Total N Total P

Jan-10 62453 30996 38827 3043 510

Feb-10 55668 20812 25724 2736 267

Mar-10 66530 25460 34202 3585 517

Apr-10 59562 22324 32017 3409 472

May-10 57038 21211 28746 4011 511

Jun-10 50343 20881 25909 3745 471

Jul-10 63681 24637 33259 2943 426

Aug-10 66581 20907 26692 4976 643

Sep-10 42493 16005 21119 1818 255

Oct-10 49530 20357 22434 4033 559

Nov-10 34300 15317 17932 2370 311

Dec-10 29615 13577 14023 1789 252

Total 637794 252484 320884 38457.42 5193.019

3. Licence-Specific Reports

Table 2 Discharged Effluent Loadings

COD Kgs EFF% BOD Kgs EFF% ss Kgs EFF% TN Kgs EFF% TP Kgs EFF%

Jan-10 5409 91% 1014 97% 1690 96% 2476 19% 0

Feb-10 11518 79% 720 97% 3599 86% 1882 31% 0

Mar-10 11308 83% 962 97% 3850 89% 938 74% 289 44%

Apr-10 9107 85% 934 97% 1635 95% 1915 44% 306 35%

May-10 11669 80% 972 97% 1945 93% 1386 65% 372 27%

Jun-10 11342 77% 642 98% 4922 81% 1798 52% 402 15%

Jul-10 4065 94% 325 99% 2276 93% 1561 47% 346 19%

Aug-10 8076 88% 261 99% 1433 95% 1029 79% 328 49%

Sep-10 5455 87% 303 99% 2727 87% 1364 25% 300 -18%

Oct-10 5124 90% 331 99% 2149 90% 1504 63% 293 48%

Nov-10 3178 91% 530 97% 662 96% 901 62% 233 25%

Dec-10 3726 87% 186 99% 466 97% 429 76% 144 43%

Total 89977 86% 7180 98% 27354 91% 17181 55% 3013 42%

12

Data Collection and Reporting Requirements under the Urban Wastewater Treatment Directive

3.2 Storm Water Overflow Identification and Inspection Report

4.12.1 The licensee shall, prior to the date for submission of the second AER (required under Condition

6.12), carry out an investigation for the identification and assessment of storm water overflows. A report on

the storm water overflows shall be submitted to the Agency as part of the second AER. The assessment

shall include a determination of compliance with the criteria for storm water overflows, as set out in the

DoEHLG ‘Procedures and Criteria in Relation to Storm Water Overflows’, 1995 and any other guidance as

may be specified by the Agency.

Report:

An assessment of the overflows has been carried out by reference to the design of the Dungarvan

sewerage scheme by Waterford County Council. The sewerage scheme is new, being constructed between

2004 and 2007. The initial design of the scheme and preliminary report for the scheme, along with EIS were

completed in 1994. This date precedes the publication of the 1995 Criteria for Storm overflows so the

design of the scheme was using accepted criteria for sewerage schemes pertaining at the time. An

extensive study was carried out to assess the suitability of the level of and frequency of discharges

expected from Storm overflows. Each was examined and simulated in a computer programme and deemed

to satisy the environmental requirements. Reference should be made to the analysis contained in Appendix

B, ”storm water overflows and pump stations” in the application for this licence.

Dungarvan sewerage scheme comprises a number of sub catchments each delivering to individual

pumpstations, from where a multiple of Dry Weather flow is pumped forward in the network until the waste

water arrives at Shandon Pumpstation. Each pumpstation has an overflow facility that acts as a storm

overflow in times of rainfall when pumped forward flows are exceeded. Shandon pump station has its own

contributing catchment as well as the pumped inputs from the other peripheral stations. Both SW2 and SW3

are outlined below on account of they differing from other points in as far as location level dictates that the

stormwater has to be pumped to discharge from them.

SW2 is the main pump station pumping to the Waste water treatment plant. Its pumping capacity, via two

rising mains is 650m3 per hour to the plant. Any flows into the station in excess of this are overflowed via a

screen to a storm well and subsequently discharged by pumping to the Colligan Estuary.

This discharge would comply with Formula A discharges to non sensitive areas according to DoEHLG

„Procedures and Criteria in relation to Storm Water Overflows, 1995’. Using a population of 9000 a domestic

contribution of 225litres/day and a industrial loading of 400m3 per day, Formula A flows are calculated as

9000x0.225 + 1.36x9000+2x400 = 15,065m3/day = 627m3/hr. This is less than the 650m3 pumping

capacity.

SW3 : This discharge point is a storm water overflow at Fr Twomey‟s road pumpstation. The pump station is

designed to pump forward multiple times the dry weather flow. The capacity of the pumps is up to 230m3

hour forward via the network to Shandon station. The contributing catchment population is not calculated so

the compliance of the Storm overflow threshold against formula A flows is not currently proven. Given the

design philosophy adopted for this new station, along with the catchment size being less than 25% of the

whole scheme, is quite reasonable to accept that the forward flow capacity exceeds Formula A flow values.

13

SW4 to SW19. Examination of these outfall locations against the design documents has lead to inability to

prove compliance on all. The bulk of these, by reference to original licence application, complied with

currently required criteria. To carry out an assessment to prove performance on these overflow locations,

relative to current regulation, will require an extensive re examination of the scheme and modelling of the

scheme. As there are other licence issues, such as discontinuing discharges at key locations, the full

assessment is a candidate for WSIP type projects.

Discontinuation of SW2 and SW3, and further stormwater overflow assessment: Both these discharge

points are storm overflows as well as pumpstations. Elimination of these discharges will require a complete

re-design of the collection system, the pump stations and the Waste water treatment plant. The nature and

extent of the work involved could not be implemented by the local authority under its own finances and

would have to be put forward under the WSIP (Water Services Investment Programme). The current WSIP

programme is 2010 to 2012 and the required works for planning are not in this programme. The next

programme would hopefully be 2012 to 2014 and the design/ planning can be put forward for this

programme as a proposal, when a call for proposals is received from the DoEHLG. The following process

will have to be followed:

1: The scheme has to be put into the assessment of needs of the Local Authority, the current assessment is

2009. There is a possibility that a review of the current assessment or a call for a revised assessment under

specified national criteria would happen in 2011. This would be a request from the DoEHLG. It is also

possible that a review of the WSIP programme would be called for in 2011 and if so the scheme can be

proposed for acceptance to the WSIP.

1: An extensive design and modelling of the network must be carried out to evaluate the performance of the

storm overflows and to then agree with the Agency as to the appropriate direction to take. This design/

planning has to be carried out as a scheme “under planning” under the Water Services Investment

Programme (WSIP), due to the task size of design and the implications for works.

2: If the scheme is deemed to require from the planning stage to stop discharges at SW2 and SW3, the

whole of Dungarvan Sewerage scheme has to go forward for Planning and design and this will include the

New Waste water treatment plant. A similar and smaller agglomeration of Tramore is currently at planning

stage for network improvements, including reducing Storm water overflows. This scheme is currently

estimated to cost €11m. Given the larger network of Dungarvan and its layout, the likely costs of such

measures would exceed €20m.

3.3 Development/Infrastructural Works Summary (completed for previous year or prepared for current year)

5.1 The licensee shall, as a part of the second AER (required under Condition 6.12), prepare and submit to

the Agency a programme of infrastructural improvements to maximise the effectiveness and efficiency of

the waste water works in order to:

a) achieve improvements in the quality of all discharges from the works; The WWTP is new,

commissioned in 2007. No proposals for improvement as it is showing compliance with the licence.

b) meet the emission limit values specified in Schedule A: Discharges, of this licence; Schedule A1

relates to the treatment plant, and compliance is shown. Schedule A2 is for a discharge that is

programmed for discontinuation and replacement with a compliant storm water overflow. A3 and A4

schedules do not relate with the waste water works.

14

c) give effect to Regulation 2 of the Waste Water Discharge (Authorisation) Regulations 2007 (S.I. No.

684 of 2007); Section 2 of S.I.684 is a statement of the purpose of the said regulations and the

licence instruction to give effect to same is vague ambiguous so cannot be answered.

d) reduce Total Nitrogen loadings in the discharge to the maximum practicable extent: The nitrogen

removal from the existing plant is more effective than expected from a plant of its type. The ability of

the plant to maintain the licence ELV of TON is not expected. Compliance has been achieved in

2010 only as a by product of the plants operating parameters during this period.

e) meet the obligations of Condition 1.7. This refers to treatment capacity at the WWTP and this is

currently within capacity on the principal determinant of biological loading. The Plant has a design

capacity of 25,000p.e. equivalent to 1500Kg of BOD per day for the year 2022. The plant was

constructed with a design capacity equal to the ultimate requirement for the year 2022.The current

average daily loading to the plant , as per tables on the mass loadings section 4.1 of this report is

692 Kgs/day of BOD. The plant is operating at less than 50% of its ultimate capacity.

3.4 Summary Report on Ambient Water Quality of Colligan Estuary and Dungarvan Harbour, pursuant to the requirements of the Shellfish Directive (2006/113/EC)

5.8 The licensee shall carry out an assessment of the impact of the discharge(s) from the waste water

works on the microbiological quality (including viruses) of the shellfish in the adjacent designated shellfish

waters in consultation with the Sea Fisheries Protection Authority, the Marine Institute and An Bord Iascaigh

Mhara. The assessment shall be submitted to the Agency as part of the second AER.

Monitoring of water quality and shellfish is carried out by responsible bodies apart from Waterford County

Council. Waterford county Council have not carried out any separate monitoring regime as it not its area of

expertise. Below find monitoring of water quality as supplied by the DoEHLG, Sea Fisheries Protection

Agency dealing with shellfish waters.

SWD designated monitoring points compared with actual sampling undertaken under the

SFPA monitoring programme (November 2008-December 2010)

Designated Area Species Comment

Dungarvan Bay PO

SFPA sample location closely matches designated

sampling location.

Species code: PO Pacific oysters;

For assessment purposes a value of 230 E. coli MPN 100g-1

was considered equivalent to the

directive guide value of 300 faecal coliforms MPN 100g-1

.

E. coli data used to make assessment of compliance with the Guide Value

SWD Site

E. coli MPN 100g-1

Nov-08 Feb-09 May-09 Aug-09 Nov-09 Feb-10 May-10 Aug-10 Nov-10

Dungarvan

Harbour 160 <20 20 430 490 170 20 230 230

Assessment of compliance with guide value of 230 E. coli MPN 100g-1

between November 2008 and

November 2010

15

SWD Site

Percentage Compliance with E. coli 230 MPN 100g

-1 (n)

Comment

2009 (n=4)* 2010 (n=4)* 2008-10 (n=9)*

Dungarvan Harbour

50

100

78

16

4.1 Annual Statement

7.2.1 The licensee shall as part of the AER provide an annual statement as to the measures taken or

adopted in relation to the prevention of environmental damage, and the financial provisions in place in

relation to the underwriting of costs for remedial actions following anticipated events (including closure) or

accidents/incidents, as may be associated with discharges or overflows from the waste water works.

The statement of measures and assessment of risks associated with Dungarvan treatment plant is

contained in the ELRA attached, as far as it is possible to ascertain these risks. On the issue of underwriting

costs: Waterford Co. Council has a long term contract in place for the operation of the waste water

treatment plant and is committed to financing same. Local authorities are state bodies and dependant on

Government for funding. Financial provisions for remedial works, if required, would come from current

annual revenue funds, as far as these would be available.

4.2 Environmental Liabilities Risk Assessment

7.2.2 The licensee shall arrange for the completion, by an independent and appropriately qualified

consultant, of a comprehensive and fully costed Environmental Liabilities Risk Assessment (ELRA) to

address the liabilities from present or planned discharges. A report on this assessment shall be submitted to

the Agency for agreement as part of the second AER (required under Condition 6.12). The ELRA shall be

reviewed as necessary to reflect any significant change to the volume or character of effluent discharged,

and in any case every three years following initial agreement (the results of the review shall be notified as

part of the AER).

ELRA attached.

4. Environmental Liabilities

| PRTR# : D0017 | Facility Name : Dungarvan UDC Waste Water Treatment Plant | Filename : D0017_2010(1).xls | Return Year : 2010 |

Guidance to completing the PRTR workbook

AER Returns Workbook

Version 1.1.11

REFERENCE YEAR 2010

1. FACILITY IDENTIFICATION Parent Company Name Waterford County Council

Facility Name Dungarvan UDC Waste Water Treatment Plant

PRTR Identification Number D0017

Licence Number D0017-01

Waste or IPPC Classes of Activity No. class_name

30.4 General

Address 1 Civic Offices

Address 2 Davitts Quay

Address 3 Dungarvan

Address 4 Co. Waterford

Country Ireland

Coordinates of Location -7.55505 52.0805

River Basin District IESE

NACE Code 3700

Main Economic Activity Sewerage

AER Returns Contact Name John O Sullivan (D0017)

AER Returns Contact Email Address [email protected]

AER Returns Contact Position Senior Executive Engineer

AER Returns Contact Telephone Number 058 20807

AER Returns Contact Mobile Phone Number

AER Returns Contact Fax Number 058 20883

Production Volume 0.0

Production Volume Units

Number of Installations 0

Number of Operating Hours in Year 0

Number of Employees 0

User Feedback/Comments

Web Address

2. PRTR CLASS ACTIVITIES

Activity Number Activity Name

5(f) Urban waste-water treatment plants

3. SOLVENTS REGULATIONS (S.I. No. 543 of 2002)

Is it applicable?

Have you been granted an exemption ?

If applicable which activity class applies (as per Schedule 2 of the regulations) ?

Is the reduction scheme compliance route being used ?

http://www.epa.ie/downloads/advice/aerprtr/completinguploadingtheprtrworkbook/#d.en.30355

Environmental Liability Risk Assessment

Dungarvan Agglomeration D0017-01

January 2011


240401 X A

F:\infocorr\DATA\241036\24103600036n.doc

30 November 2010

Environmental Liability Risk Assessment

Dungarvan Agglomeration D0017-01

January 2011


Mott MacDonald, 5 Eastgate Avenue, Eastgate, Little Island, Cork, Co Cork, Ireland

T +353 (0)21 4809 800 F +353 (0)21 4809 801, www.mottmac.com

Environmental Liability Risk Assessment D0017-01

Mott MacDonald, 5 Eastgate Avenue, Eastgate, Little Island, Cork, Co Cork, Ireland

T +353 (0)21 4809 800 F +353 (0)21 4809 801, www.mottmac.com

Revision Date Originator Checker Approver Description

A January 2011 A. Lambe F. McGivern F. McGivern Initial issue

Issue and revision record

This document is issued for the party which commissioned it

and for specific purposes connected with the above-captioned

project only. It should not be relied upon by any other party or

used for any other purpose.

We accept no responsibility for the consequences of this

document being relied upon by any other party, or being used

for any other purpose, or containing any error or omission which

is due to an error or omission in data supplied to us by other

parties

This document contains confidential information and proprietary

intellectual property. It should not be shown to other parties

without consent from us and from the party which

commissioned it.

241036/N/R/03/A 29 March 2011 ELRA Dungarvan 2010 24103600036n.doc


Chapter Title Page

1. Introduction 1

1.1 General ___________________________________________________________________________ 1 1.2 Background ________________________________________________________________________ 1

2. Environmental Sensitivity 3

2.1 Environmental Sensitivity of Receiving Water ______________________________________________ 3 2.2 Groundwater Protection ______________________________________________________________ 3 2.3 Protected Ecological Sites and Species __________________________________________________ 3 2.4 Human Health ______________________________________________________________________ 4

3. Risk Assessment 6

4. Risk Prevention/ Mitigation 11

5. Statement of Measures 12

6. Financial Provisions 15

6.1 Estimation of Remediation Costs ______________________________________________________ 15 6.2 Details of Financial Provision/ Insurance ________________________________________________ 18

Content


1


1.1 General

This Environmental Liability Risk Assessment relates to the agglomeration of Dungarvan. This report has

been prepared in compliance with Condition 7.2.2 of Licence No. D0017-01 which requires:

“The licensee shall arrange for the completion, by an independent and appropriately qualified consultant, of

a comprehensive and fully costed Environmental Liabilities Risk Assessment (ELRA) to address the

liabilities from present or planned discharges. A report on this assessment shall be submitted to the Agency

for agreement as part of the second AER (required under Condition 6.12). The ELRA shall be reviewed as

necessary to reflect any significant change to the volume or character of effluent discharged, and in any

case every three years following initial agreement (the results of the review shall be notified as part of the

AER).”

This report was prepared in accordance with the Environmental Protection Agency Guidance on

Environmental Liability Risk Assessment, Residuals Management Plans and Financial Provision, and the

Environmental Protection Agency Guidance on the Preparation & Submission of the Environmental Liability

Risk Assessment (ELRA) for The Annual Environmental Report (AER) for Waste Water Discharge

Licences.

1.2 Background

This Environmental Liabilities Risk Assessment relates to the Dungarvan Agglomeration. The current

population equivalent of the agglomeration is approximately 13,000. The Dungarvan Wastewater

Treatment Plant (WWTP), located at Ballynacourty, commenced operation in July 2007 and is designed to

serve a population equivalent of 25,000.

The waste water works for the agglomeration of Dungarvan includes all the sewers, their accessories and

all structural devices for the collection, storage, treatment or discharge of waste water. The Works includes

the pumping stations, rising mains, sewers and ancillaries utilised for conveying waste water from

Dungarvan to the waste water treatment plant at Ballynacourty commissioned in 2007. These works were

constructed under the Dungarvan & Environs Sewerage Scheme. The catchment area of Ballinroad has

also been included in the agglomeration as it is planned that waste water from this area will be conveyed to

Ballynacourty WWTP in the near future.

The treatment works at Ballynacourty treats domestic, commercial and industrial effluent from Dungarvan

town and surrounding areas. This wastewater is transferred to the Ballynacourty site via twin rising mains

from Shandon Pumping Station. The treatment plant also treats domestic and trade effluent from the

Ballynacourty & Clonea area. This wastewater is transferred to the Ballynacourty treatment plant site via

one single rising main. The treated effluent is discharged via a diffuser into the outskirts of Dungarvan

Harbour.

The plant at Ballynacourty provides preliminary and secondary biological treatment (activated sludge). The

design flows for the Works (year 2022) are 4,920 m3/d.

There are three rising main incoming sewers to the inlet works at Dungarvan WWTP, two from Shandon

pumping station and one from Ballynacourty pumping station. The three sewers enter the plant in the inlet

chamber. All flows into the plant receive screening and grit removal at the inlet works. The preliminary

1. Introduction


2


treatment consists of fine screening by two stream automatic bar screens and a bypass coarse screen.

After the screens, the grit is removed from the liquid stream by means of a vortex type grit trap and

transferred to a skip for disposal offsite. Screenings are dewatered and transferred to a skip for offsite

disposal.

A storm tank is also provided with a storage volume of approximately 1,000m3.

The screened sewage flow is measured in the inlet flume. From here the sewage gravitates to the splitter

chamber where flow is split over the two aeration tanks. The sewage is also mixed in the splitter chamber

with return activated sludge (RAS). The sewage undergoes treatment in the two aeration tanks. The

sludge/treated water mixture then gravitates to the clarifiers. Clarified effluent flows through the final

effluent flume and the effluent is discharged via the final outfall into the sea.

Sludge undergoes dewatering and thermal drying on site to produce a final product which meets the

requirements for use in Agriculture. The treatment plant is designed to treat sludge for a population

equivalent of approximately 75,000 PE, this figure includes sludge imported for treatment.

Waste activated sludge (WAS) is removed from the WAS pumping station and is pumped into the sludge

blending tank or used for imported sludge cake re-liquidification. Imported sludge cake is dropped into the

sludge cake bunker. The sludge cake is re-liquified and pumped though one of the imported sludge

screens after which the sludge pumping station into the sludge blending tank. Imported liquid sludge is

screened by one of the imported sludge screens. After screening, the sludge gravitates to the liquid sludge

pumping station from where it is pumped into the sludge blending tank. Ferric Chloride is dosed into the

sludge blending tank. Sludge in the sludge blending tank is dewatered by the centrifuge and transferred to

the sludge dryer. The dried sludge from the sludge dryer is transported by a screw conveyor into a sludge

silo. From the sludge silo, sludge can be transported into a truck for removal offsite or can be transported to

the sludge bagging system for sludge storage.

Odour extraction is carried out at the inlet works and the sludge treatment area. Dust extraction is carried

out at the bag filling station and the sludge treatment area.

The Ballynacourty wastewater treatment plant is operated 365 days of the year and is manned from 8am to

6pm Monday to Friday. The Works are monitored by a SCADA system which alarms in the event of system

failure. However it should be noted that the plant is designed on a duty/stand-by basis in order that there is

a back-up system in place in the event of a failure thus giving the caretaker time to replace equipment etc.

and preventing the plant from backing up with effluent.

The EPA Report Urban Waste Water Discharges in Ireland for Population Equivalents Greater than 500

Persons (A Report for the Year 2006 – 2007), reported that the Dungarvan WWTP was in compliance with

the Urban Waste Water Regulations in 2006 and 2007.


3


The main considerations in relation to the receiving waters for the discharge were identified. Each

environmental attribute is described in detail below, which is the basis of the designated score assigned to

each attribute in Table 1.

2.1 Environmental Sensitivity of Receiving Water

Dungarvan Harbour is an estuary with three rivers discharging into it, the Colligan, the Brickey and the

Glendine. Dungarvan Harbour is not designated as a sensitive area with respect to the Urban Waste Water

Treatment Regulations (S.I. 254 of 2001) or any of the current amendments thereof.

Water quality in Dungarvan Harbour was categorised as being unpolluted for the period 2001 -2005,

however, the Water Quality in Ireland 2004-2006 (EPA, 2008) report and Water Quality in Ireland 2007-

2008 Key Indicators of the Aquatic Environment (EPA, 2009) classed Dungarvan Harbour as intermediate.

The water quality of the inner harbour and Colligan Estuary was categorised as intermediate also.

The interim classification (WFD) of Dungarvan Harbour was moderate. The Coastal Waters of Dungarvan

Harbour are classed as 1(b) Probably at risk of not achieving Good Status.

2.2 Groundwater Protection

Carboniferous limestone and shales underlie the area, the site slopes from a level of approximately 13m

O.D. at NW corner in a south-easterly direction to approximately 11m O.D., at a slope of less than 1%. The

groundwater mapping section of www.gsi.ie was consulted to determine the type and vulnerability of the

aquifer.

The draft aquifer map indicates that the Dungarvan Catchment overlies a Regionally Important Aquifer –

Karsified (diffuse). This aquifer has an extreme vulnerability classification (interim).

There were no wells identified in the vicinity of the site (source – www.gsi.ie).

There are no direct discharges to groundwater.

2.3 Protected Ecological Sites and Species

Protected Areas in the vicinity of the discharge include:

Dungarvan Harbour SPA Site Code 004032

Dungarvan Harbour pNHA Site Code 000663

Helvic Head NHA/cSAC Site Code 000665

Ballyquinn Head SPA Site Code 004192

The primary discharge point is off Ballynacouty Point and is 0.2km east of the Dungarvan Harbour SPA and

2km east of the Dungarvan Harbour pNHA. The discharge is also 2km north northwest of the Helvic Head

NHA/cSAC and Ballyquinn Head SPA.

Dungarvan Harbour has been designated as a Special Protection Area (SPA) for wild birds. The areas

covered by this designation include the intertidal foreshore, part of Whitehouse bank, all of Western Bay,

the foreshore at Spit Bank between Abbeyside and Ballynacourty and the mudflats on the Colligan Estuary

2. Environmental Sensitivity

http://www.gsi.ie/

http://www.gsi.ie/


4


upstream of Dungarvan Town. A major part of the ecological importance of the bay is the wintering birdlife

which is present in large numbers.

Dungarvan Harbour is a proposed National Heritage Area under the Wildlife Act. The proposed NHA

includes the intertidal portion of the Colligan, Glendine and Brickey rivers, the intertidal mudflats of the

harbour proper.

Helvick Head is situated on the southern side of Dungarvan Harbour in Co. Waterford. The site is a

candidate SAC selected for dry heath and vegetated sea cliffs, both habitats that are listed on Annex I of

the E.U. Habitats Directive. Helvick Head has important breeding seabird populations; it is of high

ornithological importance, with one seabird species having a population of national importance. The

presence of breeding Chough and Peregrine is also of note.

Helvick Head to Ballyquin SPA is a linear site situated on the south-west coast of Co. Waterford. It includes

the sea cliffs and land adjacent to the cliff edge (inland for 300 m) between Helvick Head in the east and

Ballyquin townland in the south-west. The high water mark forms the seaward boundary, except around

Helvick Head where the adjacent sea area to a distance of 500 m from the cliff base is included to provide

areas for foraging and socialising activities for breeding seabirds.

The site is a Special Protection Area (SPA) under the E.U. Birds Directive, of special conservation interest

for the following species: Chough, Peregrine, Cormorant, Herring Gull and Kittiwake.

2.4 Human Health

Clonea Beach, which is circa 1.7km North of the primary discharge point, retained its Blue Flag in 2010.

Clonea Beach was found to have good water quality status in the EPA report Quality of Bathing Water in

Ireland, A Report for the Year 2008. Bonmahon Beach, which is >5km northeast of the primary discharge

point was awarded a Blue Flag in 2010.

The primary discharge does not discharge directly into the designated shellfish water. There is a trestle

oyster cultivation system in operation around the low water mark on Whitehouse Bank, c. 3.5km south west

of the primary discharge. This area of Dungarvan Harbour was designated a shellfish water under the

European Communities (Quality of Shellfish Waters) (Amendment) Regulations, 2009 (SI No. 55 of 2009).

Dungarvan Harbour passed the Shellfish Waters Directive criteria for metals and organics in 2007.

However the draft Dungarvan Harbour Pollution Reduction Programme (2009) identifies faecal

contamination within/in the vicinity of the Shellfish area as the key pressures affecting the shellfish waters

of Dungarvan Harbour, with urban wastewater systems being identified as one of main contributors to this

problem.

There are no water abstractions downstream of the discharge.


5


Table 1: Environmental Sensitivity Assessment

Environmental Attribute Attribute Score Designated Score Comment

Sensitivity of Receiving Water

Class A (Q5, Q4-5, Q4) 3

Class B (Q3-Q4) 2

Class C (Q3, Q2-3) 1

Class D (Q2, Q1-2, Q1) 0

Designated Costal & Estuarine Waters 2

Potentially Eutrophic Coastal & Estuarine 1 1 See Section 2.1

Groundwater Protection

Regionally Important Aquifer 2

Locally Important Aquifer 1

Poor Aquifer 0 2

Vulnerability Rating - Extreme 3

Vulnerability Rating - High 2

Vulnerability Rating - Moderate 1

Vulnerability Rating - Low 0 3 See Section 2.2

Protected Ecological Sites and Species (Shortest distance from any discharge)

Discharge within or directly bordering a designated site 2

<1km 1

>1km 0 2 See Section 2.3

Human Health

Discharge within or directly bordering a designated shellfish area

0 - 5 km 1

>5 km 0 1

Designated Bathing Water

WITHIN 0-5 km 1

>5 km 0 1

Drinking Water Source

Within 0-10 km 1

>10km 0 0 See Section 2.4

Environmental Sensitivity Score 10


6


The risk identification process involved:

The identification of potential environmental receptors at the site

The identification of WWTP processes that posed potential hazards to the environmental receptors

The identification of risks associated with the processes

The potential environmental receptors and site sensitivity were discussed in Section 2.

A site visit was undertaken on the 25th January 2010, with the Site Manager Nicholas Lehane following

which the risk assessment was conducted.

The Risk Assessment form (Table 2) identifies all risks which are associated with the process. Risk

rankings were applied to each risk for severity and occurrence in accordance with the risk classification

tables (Table 5 and 6). The overall risk score was calculated for each risk i.e. the risk score is a product of

the risk severity and risk occurrence rating.

3. Risk Assessment


7


Table 2: Risk Assessment Form

Risk

ID Process Potential Hazards Environmental effect Severity

Rating Basis of Severity Occurrence

Rating Basis of

Occurrence Risk Score

1 Inlet works Blockage Untreated wastewater discharge to groundwater/ surface water

2 Duration would be short, blockage would be noticed. Bypass screens in place.

3 2 automatic screens and bypass screen. Screens are regularly inspected. Pumped flow to inlet.

6

2 Operation of plant under storm events

Storm water (continuous pumping of wastewater to plant) resulting in washout of bacteria.

Untreated wastewater discharge to surface water

2 Wastewater is pumped to site, storm water tank provided.

2 No reports of storm events causing problems at site.

4

3 Biological Tank Failure of aeration/ insufficient aeration capacity to treat incoming load

Receiving waters -Depletion of D.O., nutrient enrichment.

3 Remediation of river, and protected habitats.

4 Plant designed for carbonaceous oxidation, aeration system does not have capacity to achieve nitrogen limits set under licence for design load, D.O. monitors, monitoring of D.O. Standby blowers. Trained operatives onsite, monitoring of process.

12

4 Biological Tank Washout of MLSS, failure/insufficient biological treatment, discharge of untreated/ partially treated wastewater

Receiving waters -Depletion of D.O., nutrient enrichment, potential fishkill

3 Remediation of river, and protected habitats.

4 Plant designed for carbonaceous oxidation, plant does not have capacity to achieve nitrogen limits set under licence for design load, MLSS monitors, monitoring

12


8


Risk ID

Process Potential Hazards Environmental effect Severity Rating

Basis of Severity Occurrence Rating

Basis of Occurrence

Risk Score

of D.O. Trained operatives onsite, monitoring of process.

5 Clarifier Failure of critical equipment leading to solids carryover in effluent

Suspended solids concentration in the receiving water

3 Impact on receiving waters would be short

2 MLSS monitoring and monitoring of process, failure would be noticed.

6

6 Sludge Imports/ Exports Spill onsite Groundwater pollution - subsequent impact on watercourses

3 Hardsurfaced area, which has surface drains which drain to inlet works. Spill could be contained. But high volumes of sludge onsite.

3 High volume of sludge for transport on/off site. Experienced site personnel.

9

7 Sludge Treatment Spill onsite Groundwater pollution - subsequent impact on watercourses

3 High volumes of sludge onsite, risk highest of liquid sludges.

3 Constructed and last integrity tested in 2006. Regular inspection and maintenance. Experienced site personnel.

9

8 Supernatant return Failure of pumps Groundwater pollution - subsequent impact on watercourses

3 Small quantity of high strength wastewater.

2 Pumps linked to plant SCADA, failure would be noticed.

6

9 General - chemical spill Spill onsite Groundwater pollution - subsequent impact on watercourses

2 Small quantities of chemicals onsite.

3 Bunded polymer dosing area. Ferric chloride currently not bunded. Experienced personnel onsite.

6


9


Risk ID

Process Potential Hazards Environmental effect Severity Rating

Basis of Severity Occurrence Rating

Basis of Occurrence

Risk Score

10 General - diesel spill Spill onsite Groundwater pollution - subsequent impact on watercourses

3 Moderate volumes of diesel onsite.

2 Bunded tanks, experienced personnel onsite.

6

11 General - power failure Power Failure - Washout of MLSS, failure of biological treatment, discharge of untreated wastewater

Receiving waters -Depletion of D.O., nutrient enrichment, potential fish kill

3 Backup generator onsite, no history of power failure onsite. Duration would be short.

1 No reported problem with ESB supply. Backup generator onsite.

3

12 General - tank failure Tank failure Groundwater pollution - subsequent impact on watercourses

4 Contamination could be ongoing for a long period of time if leak not detected. Possible need to pump and treat groundwater and soil.

2 Constructed and last integrity tested in 2006. Regular inspection and maintenance.

8

13 General - pipe failure Pipe Failure Groundwater pollution - subsequent impact on watercourses

3 Contamination could be ongoing for a long period of time if leak not detected. Possible need to pump and treat groundwater and soil.

2 Constructed and last integrity tested in 2006. Regular inspection and maintenance.

6

14 WWTP operation Fire at WWTP (firewater) Groundwater pollution - subsequent impact on watercourses

4 Possible need to pump and treat groundwater.

2 Moderate quantities of hydrocarbons stored onsite.

8

15 WWTP site Flooding Receiving waters -Depletion of D.O., nutrient enrichment, potential fish kill. Groundwater

4 Remediation of soil, groundwater and estuarine habitats.

1 No history of flooding onsite, site elevated.

4


10


Table 3: Risk Matrix

V. High 5

Oc

cu

rre

nc

e High 4

3, 4

Medium 3

1, 9 6

Low 2

2 5, 7, 8, 10,

11, 13 12, 14

V. Low 1

15

Trivial Minor Moderate Major Massive

1 2 3 4 5

Severity

These are considered to be high-level risks requiring priority attention. These risks have the potential to be catastrophic and as such should be addressed quickly.

These are medium-level risks requiring action, but are not as critical as a red coded risk.

Green (light and dark green) – These are lowest-level risks and indicate a need for continuing awareness and monitoring on a regular basis. Whilst they are currently low or minor risks, some have the potential to increase to medium or even high-level risks and must therefore be regularly monitored and if cost effective mitigation can be carried out to reduce the risk even further this should be pursued.


11


The risk matrix indicates that there are no risks in the yellow or red zones requiring priority attention.

All are located in the green zone indicating a need for continuing awareness and monitoring on a regular

basis. However, assessment of the green zone risks during the process has indicated that some of these

risks can be reduced through the implementation of mitigation measures. These measures should be

adopted where considered cost-effective to further reduce the risks. As these risks may have the potential

to increase to yellow or red zone risks, risk management measures should be put in place to manage them

at their current levels, or preferably to reduce them further.

Risks 3 and 4 deal with the WWTPs ability to achieve the nitrogen emission limit values set out in licence

D0017-01. At present the plant is complying with the nitrogen emission limit values, however as the plant is

not designed for nitrogen removal it is considered the occurrence of insufficient aeration (Risk 3) or

overloading of the biological treatment system (Risk 4) is high. Should the load to the plant increase above

current levels the occurrence of Risks 3 and 4 may increase to very high resulting in medium-level risks.

Measures to mitigate these risks are included in the Statement of Measures contained in Section 5.

4. Risk Prevention/ Mitigation


12


The measures to be undertaken by Waterford County Council are outlined in Table 4.

Measures are in place within Dungarvan WWTP are adequate to maintain the discharge at a quality that

complies with the licence conditions and does not significantly impact on the conservation objectives of the

protected areas within the Bay.

5. Statement of Measures


13


Table 4: Statement of Measures

Risk I.D.

Risk Score Mitigation measure to be taken Outcome Action

Date for completion

Owner/Contact Person

1 6 Continue regular maintenance and inspection. Reduced risk of blockage and

over spill. Continue regular maintenance and inspection.

ongoing Waterford County Council

2 4 Continue regular maintenance and inspection. Reduced risk from storm

events. Continue regular maintenance and inspection.


3 12

Continue regular maintenance and inspection, access aeration plant capacity to achieve nitrogen limits.

Reduced risk of aeration failure.

Continue regular maintenance and inspection. Access aeration system capacity to achieve nitrogen limits and improve infrastructure if required.


4 12

Continue regular maintenance and inspection, access plant capacity to achieve nitrogen limits.

Reduced risk of failure of biological treatment.

Continue regular maintenance and inspection. Access plant capacity to achieve nitrogen limits and improve infrastructure if required.


5 6 Continue regular maintenance and inspection. Reduced risk of failure of

clarifier. Continue regular maintenance and inspection.


6 9

Continue regular maintenance and inspection. Ensure staff training is up to date and SOPs are followed.

Reduced risk of sludge spill onsite



7 9


Reduced risk of sludge spill onsite



8 6 Continue regular maintenance and inspection. Reduced risk of failure of

clarifier. Continue regular maintenance and inspection.


9 6


Reduced risk of spill/leak onsite




14


Risk I.D.

Risk Score Mitigation measure to be taken Outcome Action

Date for completion

Owner/Contact Person

10 6

Continue regular maintenance and inspection. Ensure staff training is up to date and SOPs are followed. Bunding of ferric chloride and new dosing method to be implemented.

Reduced risk of spill/leak onsite

Continue regular maintenance and inspection. Ensure staff training is up to date and SOPs are followed. Ferric chloride bunding to be provided.


11 3

Put in place emergency procedures for prolonged power outage. Ensure staff training is up to date.

Reduced risk from power outage onsite.

Put in place emergency procedures for prolonged power outage. Ensure staff training is up to date.


12 8 Continue regular maintenance and inspection. Reduced risk from tank

failure. Continue regular maintenance and inspection.


13 6 Continue regular maintenance and inspection. Reduced risk from pipe

failure. Continue regular maintenance and inspection.


14 8

Put in place emergency procedures for dealing with fire/firewater. Ensure staff training is up to date.

Reduced risk from firewater. Put in place emergency procedures for dealing with fire/firewater. Ensure staff training is up to date.


15 4 n/a n/a n/a n/a n/a

Statement I confirm the above are the measures which will be taken by the Local Authority in 2010/2011

Signed:

Name Date


15


6.1 Estimation of Remediation Costs

The “unknown” environmental liabilities are associated with environmental risks and may or may not occur.

The best case scenario is that none of the environmental risks occur and hence at the end of the

assessment period of 30 years, the additional costs incurred by the County Council are zero. Alternatively,

should a significant number of risks materialise, significant additional costs could be incurred.

The “unknown” environmental liabilities are estimated through the use of a financial model.

Each risk has two characteristics that are derived from the Risk Classification Tables (Tables 5 and 6) that

are used in the financial model:

The range in cost implications (€A-B) if the risk occurs (Table 5)

The range in probability (X-Y%) of the risk occurring (Table 6)

Table 5: Risk Classification Table - Severity

Rating

Severity

Category

Description

Cost of Remediation

1 Trivial No damage or negligible change to the environment.

<1,000

2 Minor Minor impact/localised or nuisance 1,000 - 15,000

3 Moderate Moderate damage to environment 15,000 -75,000

4 Major Severe damage to local environment 75,000 - 150,000

5 Massive Massive damage to a large area, irreversible in medium term

150,000 - 750,000

6. Financial Provisions


16


Table 6: Risk Classification Table - Occurrence

Rating

Occurrence

Category

Description

Likelihood of Occurrence (%)

1 Very Low Very low chance (0-5%) of hazard occurring in 30 yr period *

0 – 5%

2 Low Low chance (5-10%) of hazard occurring in 30 yr period

5 - 10%

3 Medium Medium chance (10-20%) of hazard occurring in 30 yr period

10 - 20%

4 High High chance (20-50%) of hazard occurring in 30 yr period

20 - 50%

5 Very High Greater than 50% chance of hazard occurring in 30 yr period

>50%

In order to identify an indicative level of environmental liability associated with the environmental risks for

the purposes of the ELRA, a cost model has been used to generate the expected cumulative cost of the

risks as outlined in Section 4 of this report. The modelling has been undertaken using the median

probability and severity of occurrence of each risk (Table 7).


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Table 7: Financial Scenario based on Median Probability and Median Severity for each Risk

Risk ID

Severity Rating

Cost Range (€)

Occurrence Rating

Likelihood of

Occurrence Rating (%)

Median Probability

(%)

Median Severity

(€)

Most Likely Cost

Scenario (€)

1 2 1,000 - 15,000 3 10 - 20 15 8,000 1,200.00

2 2 1,000 - 15,000 2 5 - 10 7.5 8,000 600.00

3 3 15,000 -75,000 4 20 - 50 35 45,000 15,750.00

4 3 15,000 -75,000 4 20 - 50 35 45,000 15,750.00

5 3 15,000 -75,000 2 5 - 10 7.5 45,000 3,375.00

6 3 15,000 -75,000 3 10 - 20 15 45,000 6,750.00

7 3 15,000 -75,000 3 10 - 20 15 45,000 6,750.00

8 3 15,000 -75,000 2 5 - 10 7.5 45,000 3,375.00

9 2 1,000 - 15,000 3 10 - 20 15 8,000 1,200.00

10 3 15,000 -75,000 2 5 - 10 7.5 45,000 3,375.00

11 3 15,000 -75,000 1 0 – 5 2.5 45,000 1,125.00

12 4 75,000 - 150,000 2 5 - 10 7.5 112,500 8,437.50

13 3 15,000 -75,000 2 5 - 10 7.5 45,000 3,375.00

14 4 75,000 - 150,000 2 5 - 10 7.5 112,500 8,437.50

15 4 75,000 - 150,000 1 0 – 5 2.5 112,500 2,812.50

TOTAL 82,312.50


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6.2 Details of Financial Provision/ Insurance

Waterford County Council Water Services is currently reviewing their environmental liability pollution

insurance cover in the Dungarvan Agglomeration in light of this Environmental Liabilities Risk Assessment

report.

Dungarvan Waste Water Treatment Plant · 2014. 12. 16. · Wastewater treatment plant....

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