Standard Practice Manual

Version 3 Status Update

WCOWMA Convention 2014 Rupert Benzon, Michele Gee, and Mike Zemanek

Ministry of Health (Health Protection Branch)

SPM Version 3 Version 3 goals:

Practical

Easier to read and use

Shorter

Less tendency for overdesign

Flexibility

Evidence based guidelines

Clarity on ‘musts’ and ‘shoulds’

Support Public Health Protection

Latest draft is Version 3.4

Released Feb 2014 to workshop attendees

Draft - not for use

SPM V3 Project Timeline

January 2011 to

February 2013

March 2013

Oct & Nov 2013 2014 TBD

Finalized SPM V3 training, orientation,

rollout

Drafting

Expert Review

(Version 3.2)

Consultation Workshops

(Version 3.3)

Broad Consultation

SPM Consultation Workshops

Five workshops

October & November 2013

Presented by MOH in

partnership with ASTTBC

& APEGBC

Attended by APs, health

authority staff, and industry

SPM Draft Version 3.3

Reviewed, discussed, and

obtained feedback

Workshop Feedback

Feedback derived from: Workshop discussions

Feedback form Hard copies

Electronic

E-mailed comments

What we did with your comments: Response Spreadsheet

Contains all comments

MoH and contractor responses

Summary of edits to draft

SPM Draft 3.4

KEY FEEDBACK

SPM Draft 3.3

6

Key Feedback Issues Prompting

Edits to Draft 3.3 Include:

Custom designs

Repairs

Soil evaluation

Treatment vs discharge

Treatment

Design standards Daily design flow

Distribution and dosing

Vertical and horizontal separation

Hydraulic loading rate

Linear loading rates

Sand mounds

Maintenance and monitoring standards

‘Other’ issues

Custom Design

Feedback Response

Over-reliance on

professionals (custom

design)

• SPM intended to address standard site conditions

• Custom design is out of scope for the SPM

8

Repairs

Feedback Response

Will the new standards apply

to the repair of existing

systems

• Ensure systems requiring repair do not create a health

hazard

• Systems should be checked for functioning treatment

and discharge

9

Soil Evaluation

Feedback Response

There are too many soil texture

groups – needs simplification to

4 or 5

• 26 soil texture classes have been grouped into 7

soil texture groups (Table III-2)

• These texture groups were created to help with

usability of the SPM standard tables

• Balance between the differing perspectives Soil texture grouping needs

more detail (resolution)

Very gravelly sites allowed • Very gravelly sites not allowed for gravity

distribution

• Standards call for high frequency dosing

• Enables more options for gravelly sites

Treatment vs Discharge

Feedback Response

Difference between

treatment and discharge

unclear

• Treatment method is the treatment system (Type 1, 2, 3)

• Discharge area is the dispersal system

• The majority of the SPM deals with design of discharge

areas (to reach water quality objectives at the limiting

layer)

• Definitions added to glossary and Volume II

Treatment Methods

Feedback Response

Type 2 plants that do better

aren’t given credit

• The SSR only considers type 2 systems achieving 45/45

• Out of scope for SPM revision

Certification needed to

demonstrate treatment

performance

• AP responsible for selecting treatment method suitable

for site conditions

• SSR effluent requirements refer to plants in operation,

not what plants are certified to

Standards should be

consistent for CTDS and

standard dispersal systems

• The SPM standards apply to all dispersal systems

• SPM standards apply to CTDS at the point of

application

Daily Design Flow

Feedback Response

Clarification on how DDF

relates to SSR and MWR

• Added definition in glossary

• DDF is estimated peak daily flow

• Synonymous with SSR terms

• Generally represents the maximum flow the system will

discharge

Distribution and Dosing

Feedback Response

Dosing frequencies are not

feasible; will require small pipes

and risk of clogging and freezing

• Low frequency dosing option added

• Included design guidance in Volume III

• Full laterals/small orifices have not been

problematic WRT freezing

Preference given to SDD • SDD is an option available to APs

• Not necessary in most situations

• Standards reflect improved distribution

Vertical Separation

Feedback Response

Larger VS for type 2

systems doesn’t make sense

• Accounts for higher HLR for Type 2 systems (linked

standards)

• Type 2 effluent produces less biomat

• Option to use Type 1 HLR and Type 1 VS with Type 2

effluent

Horizontal Separation

Feedback Response

Additional prescribed

distances needed

• Added cisterns, transport lines, force mains, sewers,

sleeved lines, suction lines

• Adjusted setback to marine water

Question removal of

setbacks

• Some setbacks were moved to the Guidelines

Setback does not provide

sufficient protection

• Water quality objectives are met at the limiting layer

• Horizontal setbacks are based on level of risk posed by the

sewerage system on the piece of infrastructure

Hydraulic Loading Rate

Feedback Response

Prefer the old “Tyler” table • Changes made make the tables more user

friendly, especially for new APs

Loading rates have increased,

what is the justification?

• Justification laid out in Volume IV

• Based on Tyler’s table then reviewed for factors

such as BOD mass loadings, oxygen transport,

pathogen removal performance

17

Linear Loading Rates

Feedback Response

LLR does not need to be

used for most systems

• Minimum contour length option for sites up to 2400

L/day for sites with deep well-drained soils

• Should cover most single family dwellings

LLR should be based on

average flow

• LLR now based on average flow

• Tables expressed as DDF for consistency

LLR table is essentially

the same as V2, will not

lead to smaller systems

• Reduced DDF will result in smaller systems

• All LLR values reviewed and are based on Tyler and

Darcy’s law

Sand Mounds Feedback Response

Sand mounds given

special credit as treatment

method

• Sand mounds are part of the discharge area, NOT

treatment

Why not C33? • ASTM C33 does not specify fines, which can impact

sand mound performance

• Table in SPM modifies the C33 specification with detail

on fines

19

Sand Mounds

20

Maintenance and Monitoring

Feedback Response

Need way of ensuring

owners follow the

maintenance schedule

• AP’s have a good opportunity to educate homeowners

• Added emphasis on homeowner responsibility for

maintenance

• Recognized as an area for improvement outside scope of

SPM

Should mention

bylaws

• Reference to bylaws (where they exist) added to Volume II

21

Remaining Steps

Broad consultation WCOWMA convention input

Public consultation (posting on Ministry website)

Edits to generate final SPM V3

Rollout of SPM V3 Anticipate training and orientation

22

Finalized SPM V3 Including rollout

Drafting

Expert Review

(Version 3.2)

Consultation Workshops

(Version 3.3)

Broad Consultation

Thank you!

Rupert Benzon

Land Use Manager

Rupert.Benzon@gov.bc.ca

(250) 952-1501

Michele Gee

Drinking Water/Wastewater Engineer

Michele.Gee@gov.bc.ca

(250) 952-1476

Mike Zemanek

Director – Healthy Community Environments

Michael.Zemanek@gov.bc.ca

(250) 952-2372