What Do You Replace Lead Pipes With?

In the City of Toronto, you replace a buried lead water service with Type K copper. That is the thick-wall copper made for underground water lines, and it is what the inspector expects to see before the trench is closed.

Toronto Lead Pipe Solutions installs Type K copper on Toronto lead service replacements, sized to match the existing line, with lead-free fittings. The material is not a style choice. It is the one the city will sign off on.

Type K copper, and why the letter matters

Copper pipe comes in types. Type M is the thin wall used in some indoor work. Type L is thicker. Type K is the thickest of the three and the one specified for buried water services. Underground, the pipe has to take soil load, a bit of movement, and decades of contact with whatever the ground is. Thin copper is the wrong product even if it looks the same at the hardware store.

Residential services in Toronto are usually 19 mm (3/4 inch) or 25 mm (1 inch). The new pipe should match the service you already have unless the city has asked for a size change. Bigger is not automatically better, and smaller will starve the house of pressure. Soft Type K comes in coils, which is how a lot of service replacements are pulled or laid with fewer joints under the lawn.

Joints and valves on that new line should be lead-free, meaning a weighted average of 0.25% lead or less. Putting a bargain brass fitting from an unknown bin on a brand new copper service puts lead back at the joint you just paid to eliminate. Materials that touch drinking water should also be certified for that use (NSF/ANSI 61).

Where PEX fits, and where it does not

PEX is cross-linked polyethylene. It is flexible, it handles freezing better than copper, and it is a normal material for water lines inside a modern Ontario house, after the meter. If the basement is being repiped anyway, PEX or indoor copper are both reasonable. That decision is separate from the buried service.

Do not assume PEX can replace the lead pipe under a Toronto lawn. The City of Toronto standard for the water service is copper. Some other municipalities allow polyethylene or PEX for a buried service if it is on their approved list and it is installed with tracer wire, so the plastic can be found later. Peel, York, Durham, and Halton each publish their own spec. In those places the answer is still usually Type K copper for the service, and it is always whatever that region's inspector will accept. A pipe that is fine in a basement in Oshawa is not automatically fine between the sidewalk and the watermain in Toronto.

What not to use

• Galvanized steel. It rusts shut from the inside. If any lead remains upstream, the rust holds lead and lets it go later. Galvanized is a pipe we remove, not a pipe we install.
• PVC or drain pipe. White PVC is for drainage, not a pressurized drinking-water service. It is the wrong product even before an inspector sees it.
• A short piece of new copper tied onto old lead. The leftover lead is still the water's path, and the new joint can increase how much lead comes off it.
• Any fitting you cannot trace to a lead-free mark. Old stock brass is a quiet way to fail an otherwise good job.

After the new pipe is in the ground

The new copper does not make the rest of the house innocent on day one. Sediment and, if galvanized pipe is still downstream, old lead scale can sit in indoor lines and in faucet aerators. Flush the system thoroughly before anyone drinks from it. Take the aerators off and clean them. Use cold water.

If the indoor piping is galvanized and it used to be fed by lead, plan on replacing that run or testing the water after the yard pipe is done. A first-draw sample a few weeks later, taken the way a lab tells you to take it, is the check that the replacement worked. A filter can stay on the kitchen tap until that test comes back.

Trenchless methods, pipe bursting or a bore, still end at the same material question. Less lawn damage does not mean a different pipe. In Toronto the new service is still Type K copper, still permitted, still inspected.

If you are comparing quotes, ask what pipe they are installing, who pulls the permit, and whether the lead is coming out of the ground or being abandoned in it. Toronto Lead Pipe Solutions will tell you the material at the meter, quote Type K copper for the Toronto service, and put that price in writing.