Lead in Drinking Water
Although many countries have adopted regulations in recent years that limit the use of lead in the manufacture of residential plumbing products, older fixtures and lead water lines are still in service in many areas and can potentially contribute lead into a home’s drinking water supply.
NSF International has created a Consumer Guide to NSF Certified Lead Filtration Devices for Reduction of Lead in Drinking Water that explains the NSF standards and the process by which NSF International verifies a filter’s ability to reduce lead in drinking water. Some of the products listed in the guide may also be certified to reduce other contaminants besides lead. Here is a PDF that lists all filters that NSF has certified for lead reduction in drinking water.
Sources of Lead
If you live in an older home, check to see if a lead service line connects your home to the public water system. If you cannot locate the pipe or identify the pipe material, contact the local water department to see if it can inspect the water line coming into the home or check its records to confirm if the home is connected to the water system by a lead service line. The department would also be able to advise if any city water pipes in your area are known to contain lead.
Even if your home doesn’t have a lead service line, you can still have unsafe levels of lead in the water supply due to leaching of lead from fixtures like faucets as well as solder used to join pipes. Water testing can be helpful in determining if a home’s lead content is below current public health limits, which range from 0.010 mg/L in Canada and Europe (also the current WHO limit) to 0.015 mg/L in the U.S. If lead concentrations exceed the public health limits for your country, you may need to consider having older plumbing lines or fixtures replaced (assuming they are the source of the problem), using certified bottled water or using a home water treatment product certified for lead reduction.
Home Water Treatment Options
While replacing lead service lines and old fixtures may be desirable, it isn't always possible, especially if you live in a multi-unit building or rent. Depending on the lead levels being detected, home water treatment devices may be a more practical alternative. Potential treatment options for lead can include filters, reverse osmosis units and distillers. Make sure the system is certified under NSF/ANSI standards for lead reduction, which means that the system has been independently verified to be able to reduce lead from 0.150 mg/L to 0.010 mg/L or less.
If you have a private well and have high lead levels, the problem could be due to low pH. When pH levels drop below 7.0, water becomes acidic which can cause lead to leach from plumbing fixtures. Acid neutralizing systems are generally used to correct this situation. By adding a chemical like soda ash to the water to boost pH above 7.0, the system can help reduce both lead and copper leaching attributable to low pH.
If you do choose to use a water treatment system, remember that most water treatment systems have replaceable components or require regular service, so be sure to follow the manufacturer's maintenance instructions and replace filters at the recommended interval.
Low-Lead Content Laws
Many countries have adopted regulations in recent years requiring that manufacturers of plumbing fixtures reduce the amount of lead they use during the manufacturing process. In the U.S., current lead laws limit the amount of allowable lead to less than 0.25 percent by weight.
When shopping for faucets and other plumbing fixtures, be sure to read the label to verify that the products are certified for low lead content.