You may have seen stories in the media regarding lead contamination of water supplies, and we want you to know the safety of students and staff is our highest priority.
Lead in water is the result of leeching from solder, piping and brass fixtures. The longer water stands in a plumbing system, the greater potential there is for lead to leech into a supply. That means that school buildings that sit unused overnight and on weekends can have high lead levels in the water supply.
The Minnesota Department of Health (MDH) provides rigorous guidelines for addressing lead in water. Testing is the first step, and if lead levels exceed 20 parts per billion (ppb), a flushing protocol is then put in place. The testing is always conducted when it is expected to be the highest—in the morning.
About 40 of our buildings
have tested in the range prompting use of the MDH protocol. All of the 40 schools tested somewhere between 0 and 400 ppb. To put this in perspective, the lead contamination of the Flint, Michigan water supply tested in excess of 13,000 ppb. But any test at MPS exceeding 20 ppb triggers the use of the flushing process.
What this means is that every morning before any students arrive at school, engineers turn on taps throughout the buildings, in a prescribed order, and run the water for a minimum of 10 minutes. We know this works because we have conducted before and after testing to ensure it is effective. All building engineers who conduct the flushing maintain a daily log of the process. Once the flushing is complete and with fresh water coming into the building throughout the day, the lead levels remain below what has been determined to carry risk for consumption.
When renovation projects occur at our buildings, we evaluate whether it is possible to do pipe and fixture replacement to eliminate the need for flushing. This has now been done at several schools.
We also know from the Minnesota Department of Health that virtually all lead cases they see are the result of exposure at home. We encourage all parents and guardians to become knowledgeable about the risks of their homes.