Testing drinking water for lead in homes
Proper testing for lead can help you determine if your drinking water is safe.
The Flint water crisis has raised serious concerns about the safety of our drinking water, particularly regarding levels of lead. The federal Safe Drinking Water Act (SDWA) was enacted in 1974 to help ensure safe public drinking water supplies. Amendments to the SDWA specifically addressed the issue of lead in drinking water, once it became evident that the pipes supplying water to our households sometimes resulted in unsafe levels of lead.
Lead in tap water is usually the result of the distribution system and plumbing materials in the house itself, such as fixtures, lead pipes and solder. Depending on the chemistry of the water and the contact time that the water has with these materials, the pipes may corrode, leaching lead into the water. Because of this, even if the primary source of the water is free of lead (for example, water from a river or groundwater supply), once the water reaches your plumbing system it may contain unsafe levels.
You may not know when your house was built or what type of service lines or plumbing materials are in place. The only way to know if your household water supply contains lead is to test for it.
According to Michigan State University Extension, testing your water for lead is relatively easy with these easy steps. You can contact a state certified laboratory for a sample bottle. Make sure to let the laboratory know that you are interested in testing for lead, so they will send you the appropriate bottle. If you live in the city of Flint, there is currently free lead testing available.
The following are general lead sampling guidelines, but make sure that you follow the directions from the certified laboratory regarding its recommended sampling procedure. Also, be aware that lead sampling protocols are currently being discussed, and may change as more information becomes available.
When you test your water, the goal is to test for the “first draw” sample. Because lead will accumulate as the water sits in contact with the pipes in your house, you want to collect a sample that is considered representative of the water you might use when you first wake up in the morning. It is important that the water be allowed to stand in the pipes for at least six hours prior to testing. The best time to sample, therefore, may be first thing in the morning or when returning from work.
The water sample should be collected from the tap that you use most often for drinking water, such as a kitchen or bathroom faucet. Different fixtures could potentially have different levels of lead based on their age. The sample should be collected from a cold water tap. If you have a faucet with a single handle, turn it to the cold side. Make sure your hands and the sample bottle are clean. Then place the sample bottle underneath the faucet and collect the sample. Carefully place the cap on the bottle, complete the laboratory paperwork (including labeling the bottle if applicable), and ship it to the laboratory following the instructions that were sent with the sample bottle.
Action levels for lead have been established by the US Environmental Protection Agency for public water supplies. The action level is .015 milligrams per liter (mg/L) for lead (which equates to 15 parts per billion or ppb).
There are some steps that you can take to limit your exposure to lead regardless of your test results. Never use hot tap water for cooking or drinking, since lead levels will be higher in hot water supplies. This includes brushing your teeth, preparing tea or juice, and mixing baby formula.
Running your water before using it will also help to decrease levels of lead, because the longer the water has been standing in the pipes, the more contaminants it may contain. Running your tap for two minutes if the water has not been used for more than six hours is commonly recommended. Some health departments recommend running the water for up to five minutes prior to using it.
Replacing water fixtures, household plumbing and lead service lines have also been shown to reduce lead levels. Water filters can also be used to reduce levels of lead, but make sure that the filter is certified and that you are regularly replacing the filters. Water filters should be used at points in the home where you will be consuming the water. If water in your home contains high levels of lead, this will also include water from the refrigerator or ice makers in which case you should use filtered water in ice cube trays or keep cold water from a filtered tap in the refrigerator. Note that boiling the water will not remove lead and may actually increase concentrations.
If you are still concerned about levels of lead in your water supply, contact the Environmental Health Division of your local or district health department to discuss appropriate next steps.