Lead service line replacement: doing both sides, in the right order

01 /Why does full replacement matter so much?

Because cutting a lead pipe disturbs it, and whatever lead is left behind can keep releasing particles. Health Canada's guidance on controlling lead corrosion says partial lead service line replacements are generally not recommended. Its public advice explains the mechanism: if only part of a lead line is replaced, for example only the municipal part, some lead particles may detach from the remaining lead pipe for two to three months because of the disruption. EPCOR says the same thing from the utility's side: replacing only one section of a lead service line can temporarily increase lead levels.

A partial replacement also creates a joint between new pipe and old lead. Joining two different metals in water can speed up corrosion at the joint, which is one more reason programs aim to remove both sides together. Health Canada adds that any galvanized steel in the same service should be replaced as well, because galvanized pipe can hold lead released upstream; the City of Calgary says the same about galvanized piping downstream of old lead lines.

02 /How do cities coordinate the two sides?

Every Canadian program we checked is built to avoid a lasting partial replacement, but they get there in four different ways. Knowing which one your city uses tells you who books the work, who pays, and in what order.

The "owner goes first" pattern leaves a short partial period, between the owner's replacement and the city's. Hamilton gives 12 to 16 weeks, and Toronto aims for 12 weeks after an application. Filter drinking water through that gap. The rules, grants and contacts for each city are on the city programs page.

03 /What do I need to do before the work starts?

More than people expect, because the paperwork decides whether you get help. Guelph requires grant approval and a building permit before work starts, and work must start within 90 days of approval. London's loan does not reimburse lines already replaced. Halifax Water must inspect a private replacement before backfill for the rebate. Regina requires a three-way agreement and, with City financing, a contractor from its roster and at least three quotes. Winnipeg requires a City-licensed water contractor and a water connection service permit. Hamilton requires a permit, a properly installed meter and removal of any shared-service interconnection.

1. Confirm lead

   Utility record, a look at the pipe, and a water test. See how to identify a lead water pipe.

2. Read your program

   Order of work, eligibility, approvals, contractor rules and deadlines.

3. Get quotes

   At least two or three, each naming the method, pipe, length, depth, entry point and restoration.

4. Apply and permit

   Apply for help before work where required, and obtain the permit.

5. Book both sides

   Agree dates with the utility so the partial period is as short as possible, or zero.

04 /What happens on replacement day?

For a typical house, the work takes place from a pit at or near the curb stop and a pit or opening at the foundation, with the old line either dug up in a trench or replaced trenchlessly between the two. The water is off for part of the day. Public utilities are located beforehand through the provincial one-call service, and the private line may need its own locate.

1. Locates marked, the curb stop confirmed working, and the work area set up.
2. The utility or its contractor shuts the water off at the curb stop.
3. The old lead is cut out; the new pipe, usually type K copper or polyethylene, is laid in a trench or pulled, split or bored into place.
4. The new pipe is connected at the curb stop, brought through the foundation and fitted with a new main shut-off valve.
5. The line is tested for leaks and flushed before the water is used.
6. If a metal service was replaced with plastic, an electrician confirms the house's grounding.
7. Pits are backfilled and restored as the contract or program says.

The full sequence, including permits and restoration, is in the replacement process guide. Methods are compared in trenchless water line replacement.

05 /What should I do after a lead service is replaced?

Flush, keep filtering for a while, and test. Health Canada's guidance says that when lead service lines are replaced, extensive flushing of the cold water should be encouraged, and weekly or biweekly sampling at the tap should continue until lead levels stabilise. Follow any flushing instructions your utility gives; they may be specific about which taps and for how long.

• Flush the cold taps as instructed, starting nearest the entry.
• Clean aerators, where loosened particles collect.
• Keep using a certified filter for drinking until test results settle, and longer if only one side was done.
• Test on the schedule your utility or program sets; Calgary samples within a month and again at three to six months.
• Keep the paperwork: permit, inspection, invoice and test results, for grants, loans and a future sale.

Remember that the service is not the only lead source in older homes. Health Canada says the plumbing code allowed lead solder until 1986, and brass fittings can contribute. The testing guide explains how sequential samples separate the sources.

06 /How much will it cost me?

It depends far more on your city than on anything else. In Halifax the owner may pay nothing up to the funding limit; in Saskatoon the owner pays 40 percent; in Montréal the City bills an average of $1,200 to $1,400 per metre of private pipe, payable over up to 15 years; in Toronto the owner pays the private side, which a 2020 council report put at typically $2,000 to $3,000. The cost page sets out the drivers and the help in one place.

For a first read on your home and your city, run the Lead Water Line Check. For quotes on the private side, send your details.

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