About lead in water systems

What is lead?

Lead is a bluish-grey soft metal that is found in small amounts on the earth’s outer layer. Since lead is highly resistant to corrosion and very malleable, it is used in the construction of piping to transport corrosive liquids, in building construction, lead-acid batteries, bullets and shot, weights, etc. It is also part of solder, pewter, fusible alloys and radiation shields.

Where is lead most commonly found?

Lead is present almost everywhere in nature. It can be found in air, soil, dust, drinking water, food and other consumer products. Lead can be taken in by the body through ingestion and/or inhalation.

What is the acceptable lead level in Drinking Water?

In March 2019, a new lead limit was accepted under Guidelines for Canadian Drinking Water Quality. This new standard lowers the Maximum Acceptable Concentration (MAC) from 0.010 mg/L to 0.005 mg/L.

How does lead get into our water?

Lead enters drinking water by coming into contact with a lead source. If standing water (ex. overnight water in pipes) is in contact with lead materials for several hours, the water may accumulate lead levels that may become a concern.

The most common sources are:

  • Lead-based solder used to join copper pipe, faucets made of brass and chrome-plated brass, and in some cases, pipes made of lead that connect a home to the water main (service lines).
  • Lead paint and the contaminated dust and soil it generates are the leading sources of lead exposure in older housing.
  • Lead has historically been used as a component of paint, piping, solder, brass, and as a gasoline additive.

Does the age of my home matter?

Many homes constructed before the early 1960s have lead water service lines. Both lead and copper piping were used up until this time when copper water service lines became the standard in the plumbing industry. Most residential lead services are 5/8” in diameter. If your home has been renovated, the water service line may have been replaced with 3/4” water service, which would provide more consistent water pressure and higher flow rates.

Lead-based solder can be another source of lead in drinking water. This type of solder was used for plumbing until the mid-to-late eighties.

Many homes built before the early 1960s used 5/8” diameter lead piping in their construction.

Here are the steps to check if your home has lead piping:

  • Locate the water meter (usually found in the basement)
  • Look at the pipe coming up through the basement floor into the bottom of the water meter
  • Lead
    • is grey;
    • does not echo if you gently strike it;
    • scratches easily;
    • leaves metallic marks when you rub the scratched area against paper.

Note: Service line piping can also be made of polyethylene (black) or polybutylene (black or blue).

Who is responsible for the lead pipes?

The Municipal Government Act makes you, the residential property owner, responsible for the water service connection on your property as well as the plumbing in your home. Typically, lead service connections are found in older homes built before the early 1960s. The Municipality is responsible for the service connection pipes between the property line and the water main in the street.

How could lead impact me?

Corrosion inside metal water pipes within your home can cause copper, lead or iron to leach into the water supply. Lead has been identified as the main contaminate of concern by Health Canada, as it can cause health issues. Fetuses, infants and children are most at risk for neurodevelopmental adverse health effects from lead.

Am I affected?

If your home was constructed pre-1960, building codes allowed the use of lead piping for home water services, as well as plumbing solder and brass fittings with high lead content. These are the primary sources of lead contamination in drinking water.