Preventing Lead Contamination

Recent problems in Flint, Michigan, have caused people around the country to question the safety of their drinking water, specifically related to lead contamination. The City of Manhattan would like to assure its customers that providing clean, safe drinking water is one of our highest priorities. Like you, we and our loved ones drink Manhattan water every day, and it’s absolutely critical that we can all do so without concern. The goal is to provide water of the highest quality, and the City takes steps to ensure that we meet that goal each and every day.

When it comes to lead contamination, it’s important to understand how that contamination can occur. Lead isn’t found in our source water and it is not introduced during our treatment process. Lead contamination occurs when corrosive water (water with a low pH) sits in lead pipes, allowing the lead to dissolve into the water. To a lesser extent, contamination can occur when corrosive water sits in galvanized pipes, pipes with lead-based solder, or even old plumbing fixtures made of brass. These types of plumbing are sometimes found in older private residences. In 1986, Congress amended the Safe Drinking Water Act to end the use of lead in public water supply systems and private plumbing systems. We are not aware of any lead pipe being used to supply drinking water in Manhattan.

As previously mentioned, much of the problem can be attributed to corrosive water. The City is very mindful of this. Plant operators test the pH every 4 hours, and automated analyzers constantly monitor pH levels, ensuring treated water leaves the Water Treatment Plant with a pH around 9.20 pH units. As a comparison, this pH level is about as corrosive as hand soap. As part of the water treatment process, hexametaphosphate is also added to inhibit corrosion by creating a coating on the inside of pipes, acting as a barrier between the water and the pipe material, whatever that material may be.

As a result of the treatment process, lead levels in our water have been very low for many years. In fact, in 1994, KDHE recommended the City of Manhattan be put on a reduced monitoring schedule because lead was found at such low levels in our water. With the help of our customers, we collect samples every 3 years from 30 older homes and submit them to the KDHE lab for lead and copper testing. The results of these tests continue to be far below the EPA health advisory levels. Our last sampling event was in 2014. Of the 30 homes sampled, only 1 showed any detectable trace lead amounts, at a level of 2.10 parts per billion (ppb). This is a fraction of the 15.0 ppb Action Level — the level when concerns arise and action must be taken.

If you do have concerns about lead in your water, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. You may also wish to have your water tested. A list of laboratories in Kansas that are certified by KDHE to test drinking water for lead is available online.

Further information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline (800-426-4791).