Q: If the home was constructed prior to 1978, is it possible that the pipes could contain lead, and if so can the lead get into drinking water?
Background: The federal EPA has set a limit for lead in drinking water of 0.015 parts per billion. More info from the EPA is available on their site.
A: The short answer is “yes.”
Actual lead pipes have not been used for many years, however, we do rarely run across a lead water main that had not yet been replaced. In older homes, it is very common to have copper pipes that were joined using lead solder. Some brass pipes and, more commonly, brass metal within faucets and fixtures, can also contain lead. The amount of lead that will leech into water from brass pipes, brass fixtures, and copper pipes joined with lead solder depends upon water chemistry and the length of time the water sits inside the pipes before being dispensed at the tap. The lead levels can be tested by collecting a “first draw” water sample that has been sitting in the supply pipes for between 6 and 18 hours. This is enough time for lead to accumulate in the same way it would during lack of use overnight, but short enough to be representative of normal living conditions.
In addition, many municipal water systems have a small amount of lead present in the water supply as a result of old underground municipal pipe systems. As the older municipal supply pipes get replaced over time, the lead levels in municipal water will continue to decrease.
Possible solutions
A good quality point-of-use filtration system can remove 99% of lead from drinking water. Be advised, many inexpensive filters do not remove all lead from the water. Look for laboratory testing results in the manufacturer documentation. With all filters, it is very important to replace the filter media or cartridge when it is due. A filter that gets overused may develop a reduced flow rate, and will likely precipitate (add) contaminants back into the water once the filter becomes saturated with contaminants. Affected pipes can also be replaced, however, this would not eliminate common low level lead contamination found in many east coast municipal water supplies. Replacement of pipes or brass fixtures would extend the useful life of an installed filter by reducing the amount of lead filtered out.
Lastly, as the municipal water supply must meet EPA drinking water guidelines, the least expensive option is to run a small amount of water from the tap after a period of disuse to flush water that may have accumulated additional lead from the pipes before collecting water in a glass for drinking.
