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Lead and Copper Monitoring Results

Archived News Release: January 31, 2024 - In 2023 Ann Arbor completed its triennial lead and copper sampling. Samples were collected from 62 individual homes analyzed for lead and copper. Sites for compliance sampling in Ann Arbor have “Tier 3” plumbing, which means they have copper pipes installed before 1988 that are likely to have lead solder. Compliance with the lead and copper rule is determined by calculating the 90th percentile value of samples collected.

  • Ann Arbor Water’s 90th percentile value for lead was 2 parts per billion (ppb), which means 90% of the sample results measured below 2 ppb. This is well below the 90th percentile lead action level of 15 ppb lead (soon to be lowered to 12 ppb lead).
  • Our 90th percentile for copper was 100 ppb, also well below the copper action level of 1300 ppb copper.

One home had an initial test result above the lead action level of 15 ppb but Ann Arbor Water worked with the homeowner to investigate the cause of the high sample result and it was discovered that the sample was collected from a tap that had not been used for an extended period of time. Samples must be collected following at least 6 hours of stagnation, but extended stagnation does not accurately represent water that would be typically used in a home.

The City of Ann Arbor has no known homes with lead service lines, but some of our customers do have lead in their internal plumbing. Faucets, fittings, or valves sold before 2014 may have a higher lead content than newer plumbing materials. Lead solder is more likely to be found in homes with copper plumbing installed before 1988. Check out the infographics below or this link for information on how to determine if you have lead plumbing materials in your home. If your home does contain lead, you can reduce your exposure by getting the water moving before drinking it, by doing things like running the water until it is cold, washing dishes, running laundry, flushing the toilet, or taking a shower.

If you wish to have your water tested, Ann Arbor Water offers one free lead and copper test per household. Sign up for a free test kit at Ann Arbor Water uses a subcontract lab for all lead and copper analyses and every home that is sampled receives a copy of their results, whether it be voluntary testing or compliance testing for the state of Michigan.

Ann Arbor has 123,851 residents, spans 28.97 square miles and is frequently recognized as a foremost place to live, learn, work, thrive and visit. To keep up with City of Ann Arbor information, subscribe for email updates, and follow the city on Twitter and Facebook. The city's mission is to deliver exceptional services that sustain and enhance a vibrant, safe and diverse community.