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Toronto’s Management of Lead Service LinesLead Colloborative Consortium Workshop, June 8, 2012Howard Shapiro, Toronto Public Health

What is a Service Line / Water Service?

Overall Approach and Issues

• Health effects seen at levels of lead in current population

• Lead exposure should be minimized where possible

• However, issue portrayed as individual crisis• Question for TPH was is significance of

water lead levels that are slightly above drinking water guidelines• Communication to public• Management strategies

Situation

• Toronto• City 2.7 million• Very active media presence• History of lead contamination in certain

communities now largely resolved• Lead not much of an issue in recent past

• Spring 2007 lead found in London, Ontario drinking water above drinking water standard in older homes due to lead services• Toronto media asks about situation in Toronto

How Big a Problem?

• Samples from 5 Minute Flush

How Big a Problem

Early Messaging

• Desire to not counter extensive promotion of Toronto’s water

• Water leaving treatment plant very low in lead

• Water from Toronto homes within Ontario Drinking Water Standard for lead

• Homes built before 1955 usually have lead service and may have high lead in water• Can find out by requesting free water test from

Toronto Water• While waiting use water filter

Early Messaging

• Tried to provide health context• Effects of lead at this level in water would be

subtle on intelligence of children but not detectable but parent or physician

• Water one source of lead but not only one• Important in older homes with lead pipes since

likely to have lead paint, lead in soil• Takes place within trends of decreasing lead

levels over time• Developed TPH web pages for lead• Very hard to distinguish between population

and individual importance of lead

Early Program Focused on Replacement

• Of City side only• Homeowner can pay to have their side done at

same time• When:

• At time of scheduled water main replacement• During emergency repairs• In response to high lead water test• On request (long waiting period)

• Toronto Water reluctant to undertake corrosion control

Toronto Water Accelerates Program

• Estimated 65,000 lead services• 28,000 already replaced

• Original plan 13 year time frame• Accelerate replacement to 9 years

• Additional $19 million per year• Mainly through increasing main replacement in

area likely to have lead services

Province Introduces New Rules

• Requires twice yearly testing• 2 X 1 litre samples• 30 minutes stagnation after flushing• 100 homes in large city such as Toronto• Benchmark – 10 ppb 90 %ile

• Corrosion Control plan if fail 2 out of 3 consecutive rounds of testing

City Fails 2nd Round of Testing

Changes to Approach

• Trained nurses doing neonatal visits in lead water issue

• Initiated development of filter faucet rebate program

• Sent postcard to approx. 50,000 homes in areas likely to have LSL

Changes to Approach

Existing and Developing Information

• Testing of water for lead not a good way to risk stratify individual homes• Intermittent particulate release

• Impact of water on lead levels may be more significant than some studies suggested

• Replacing part of lead service with copper may be worse than leaving entire lead line

Sources of Lead In Drinking Water

Utility side Private side

Seasonal Variation in Water Lead

Further Developments Water Impact

• Edwards et al. Environ. Sci. Technol. 2009• Showed impacts of spike in DC water levels on

BLL’s• Incidence of BLL > 10 μg/dL increased 4 times

for children ≤1.3 years during time of high lead water levels

• CDC Issues notice in 2010 about past MMWR• Cross-sectional study of people with high water lead

levels (> 300 ppb) in DC flawed• Sampling time of blood and water not known

• Issue was a temporary spike in water lead levels in DC

• Also warned against partial replacement

In-house modelling (IEUBK)

Lead Levels Similar After Partial Replacement

Site T-4 (Leslie) – Partial Replacement

0

15

30

45

60

0 1 2 3 4 5 6

Cumulative Volume through Kitchen Faucet (L)

Tota

l Lea

d (m g

/L)

Before LSLR 1 Day After2 Days After 3 Days After1 Month After 2 Months After

Faucet

1/2" Cu Main

1/2" galv.

1/2" Pb

Replaced

1st Day = 411 mg/L2nd Day = 205 mg/L

Galvanic Corrosion can Increase Lead Levels

•Process used in batteries•Occurs with metals of different electrical potential•Results in corrosion of one metal•With lead and copper results in corrosion of lead• Lead levels can be higher than

lead pipe alone

Additional Changes

• Accelerated LSL replacement discontinued• Now only done as part of state of good repair

(e.g. when replacing main)• Water filter and information sheet left at each

home after all LSL replacements• Corrosion control is being implemented

Additional Changes

• Water testing de-emphasized for individual homes• Not promoted for individuals to risk stratify• People can request LSL replacement without

water testing so long as commit to replacing their side

• Vulnerable groups are encouraged to use filter until lead service removed (no longer based on testing result)

• Re-evaluating communication strategy based on survey of homes with partial and full LSL replacements

Questions

• Howard Shapiro• Toronto Public Health• hshapir@toronto.ca• 416-338-8562