Lead is a toxic material that is harmful to human health if inhaled or ingested. The human body cannot tell the difference between lead and calcium, which is a mineral that strengthens the bones. Like calcium, lead remains in the bloodstream and body organs such as muscle or brain for a few months. Lead that is not excreted is absorbed into the bones, where it can collect for a lifetime.
Young children (under the age of 6), infants and fetuses appear to be particularly vulnerable to lead poisoning. Growing children will more rapidly absorb any lead they consume. A child’s mental and physical development can be irreversibly stunted by over-exposure to lead.
Lead in Well Water
Lead can occur naturally in groundwater. If your house is served by its own private well, you can have your water tested for lead. This can be done by an accredited laboratory for a fee. A list of accredited laboratories can he found here.
The maximum acceptable concentration of lead in drinking water is 10 micrograms per litre. If your test result is greater than that, you will need to determine if the lead is present in the groundwater or coming from the plumbing. Your options may include replacing plumbing, installing a treatment system or using an alternate source of water. Bear in mind that boiling the water does not reduce the amount of lead in it.
Lead in Municipal Water
Municipal water systems in Peterborough County and City must test the water leaving the treatment plant and in their distribution systems for lead on a regular basis. Any result greater than 10 micrograms per litre must be reported to Peterborough Public Health. Fortunately, none have reported adverse results.
Municipalities and the operators of their water systems are responsible for the quality of the water they provide to their customers up to the property line (usually the shut off valve in your front lawn). Water mains under the street are generally made of cast iron or plastic. In the City of Peterborough, all known lead service lines (from the water main to the property line) have been replaced with copper. Larger water systems add corrosion inhibitors to the water to minimize the reaction between the water and any lead pipes or solder.
For annual reports which provide an overview of treatment processes and test results, visit the website of the municipality or utility service where you live.
Lead From Plumbing
Lead piping was occasionally used in “wartime” houses, which were constructed in the years 1942 to 1947. There was also some use of lead from 1898 to 1907. Homeowners can check to see if they have lead pipes by examining their plumbing lines, especially at the main shut-off valve. Copper pipe will be orange or brownish in colour. Galvanised or iron pipe be dull grey with threaded connections and will stick to a magnet. Lead pipe will have a very dark colour. Homeowners can clean a section of pipe off with a cloth, and then rub a white piece of paper on the pipe. If it looks like a pencil has been rubbed on the pipe, it is most likely lead.
Removing lead pipe from plumbing is the best way to resolve lead concerns in the home. This work is the responsibility of the homeowner and should be performed by a licensed plumber.
Lead solder which connects copper pipe and fittings, may contain lead. Lead solder was discontinued in 1993 but supplies of older solder may have been used past that date.
The longer water sits in contact with lead pipe, fittings, or solder, the more the lead leaches into the water. For this reason it is recommended that whenever water has been standing for six hours or longer, the water should be flushed for a few minutes until cold. Water use such as showering and toilet flushing will also flush standing water from your pipes. Always use cold, fresh water for drinking, cooking, making baby formula and preparing beverages. Hot water is likely to contain higher levels of lead.
Lead in Schools, Private Schools, and Child Care Centres
The Ministry of the Environment, Conservation and Parks has very strict rules governing lead testing and flushing procedures in schools and daycares. For more information please visit their website.