ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Determining Minimum Treatment Requirements for Well-Based Municipal Systems

Monica B. Emelko, Ph.D.Department of Civil & Environmental Engineering

University of Waterloo

Aziz Ahmed, P.Eng.Supervisor, Approvals and Licensing

Safe Drinking Water Branch

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Terms of Reference for the Evaluation of Water Quality to Determine Minimum Treatment Requirements for Subsurface Water Supplies

Monica B. Emelko, Ph.D.Department of Civil & Environmental Engineering

University of Waterloo

Aziz Ahmed, P.Eng.Supervisor, Approvals and Licensing

Safe Drinking Water Branch

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Overview• GUDI Terms of Reference* Review – Project Charter

• “GUDI” and associated treatment requirements 

• New ToR: Determining Treatment Requirements for Subsurface Water Supplies

• Process of Revision

• Next Steps

* Terms of Reference, Hydrogeological Study to Examine Groundwater Sources Potentially under Direct Influence of Surface Water, Oct. 2001

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Project Charter –GUDI Terms of Reference Review• 2001 GUDI Terms of Reference: old and outdated

• No change in legislation ‐ clarification & transparency

• Ensure that scarce tax dollars are spent to provide treatment and undertake monitoring, that promotes positive public health outcomes

• Update to incorporate most current consensus of science

• Objective: to ensure appropriate treatment of well water is provided by determining whether a communal well requires additional treatment beyond a minimum level of primary disinfection

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Objective of Proposed TOR:Same as 2001 GUDI TOR

Intention:To ensure appropriate treatment to reduce pathogen risk.

(also as indicated in Reg. 170/03)

• “To reduce the risk to human health attributable to diseasecausing microorganisms, Ontario has specified minimumtreatment requirements for water works. To ensureappropriate treatment is provided, the principal objective ofthis hydrogeological study is to determine whether acommunal well should be managed as a supply “under thedirect influence of surface water.”

• “To reduce the risk to human health attributable to diseasecausing microorganisms, Ontario has specified minimumtreatment requirements for water works. To ensureappropriate treatment is provided, the principal objective ofthis hydrogeological study is to determine whether acommunal well should be managed as a supply “under thedirect influence of surface water.”

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Proposed TOR Framework

Proposed TORCurrent TOR

OLDToR

Treatment Requirement

NEWToR

GW 2 log virus Category 3b4 log virus Category 3a

GUDI EF 2 log Cryptosporidium3 log Giardia4 log virus

Category 2

SW/GUDI 2 log Cryptosporidium3 log Giardia4 log virus

Category 1

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Process of Revision• Collaborative, multi stakeholder group, composed of 

municipal system owners, consultants, academic experts, and cross‐divisional ministry staff

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Key Science Foundation• There is no “easy” distinction between GW and SW.

• Many factors impact pathogen survival/transport in the subsurface.

• A different focus in conceptual transport models is required. (dissolved/aqueous compounds ≠ particles/pathogens)

• Pathogen transport/survival in the subsurface cannot be predicted. 

• Not all “indicator” data inform us in the same way. (occurrence ≠ survival ≠ transport)

• Hydrologic events are critical → so is appropriatemonitoring.

• All systems should have “basic” disinfection because of virus risk.

• Most significant well‐related pathogen risk in Ontario: fecal contamination with bacteria and viruses.

• Appropriate treatment is based on appropriatewater quality measures.

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Proposed TOR Framework

Proposed TORCurrent TOR

OLDToR

Treatment Requirement

NEWToR

GW 2 log virus Category 3b4 log virus Category 3a

GUDI EF 2 log Cryptosporidium3 log Giardia4 log virus

Category 2

SW/GUDI 2 log Cryptosporidium3 log Giardia4 log virus

Category 1

lower thresholdlower cost

higher thresholdhigher cost

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Proposed TOR Framework

Proposed TORCurrent TOR

OLDToR

Treatment Requirement

NEWToR

GW 2 log virus Category 3b4 log virus Category 3a

GUDI EF 2 log Cryptosporidium3 log Giardia4 log virus

Category 2

SW/GUDI 2 log Cryptosporidium3 log Giardia4 log virus

Category 1

health risk+

microbiologicalwater quality

+surface

connectivity(AVCP)

traditionalhydrogeology

+ microbiological

water quality+

particle countswater quality

(turbidity+DOC)

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Potential Vulnerability to Contamination by Protozoa

This drives themonitoring requirementduring theStage 2 AVCP.

ONLYpertains to

new systems.

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Next Steps• Completion of final edits of draft document• Opportunity for stakeholder comments• Finalization of document• Implementation through conditions of municipal drinking water licenses and permit

ONTARIO’S WATER CONFERENCE & TRADE SHOW • MAY 1–4, 2016

Acknowledgments• CANADIAN WATER NETWORK

Bernadette Conant, Alex Chik• MUNICIPAL STAKEHOLDERS

City of Guelph, City of Waterloo, RM of Halton, OWWA• CONSULTANTS

C3Water, Stantec, Tim Lotimer• MINISTRY OF ENVIRONMENT

Operations Division, Drinking Water Management Division, Environmental Sciences and Standards Division

• SCIENTIFIC COMMUNITYMonica Emelko, Dave Rudolph, Marylynn Yates, Nicholas Ashbolt, Pierre Payment, Benoit Barbeau, Jennifer Clancy, Ronald Harvey