Michigan CDSMI

Michigan’s Department of Environment, Great Lakes, and Energy, Drinking Water, and Environmental Health Division (EGLE) has released its guidelines for “Minimum Service Line Material Verification Requirements." As part of its guidance, EGLE says “…water supplies are not expected to physically verify every service line, but rather a statistically sound subset. To effectively evaluate the accuracy of service line records and/or predict service line materials, a representative, uniformly random number of service lines must be physically verified.”

EGLE describes two exceptions to this verification guidance:

  • A water supply may avoid the material verification process if all potable water service lines within the water supply meet the definition of “known”.

  • Water supplies may exclude service lines four inches or more in diameter. Guidance for addressing these service lines as part of the Complete Distribution System Materials Inventory (CDSMI) will be provided separately.

Guidance Summary:

  • The CDSMI is due to EGLE by January 1, 2025. EGLE suggests you consider completing this verification by the end of 2022 to allow for any additional activities that may be necessary to complete the inventory.

  • To evaluate the accuracy of potable water service line records and/or predict service line materials, a statistically sound, uniformly random number of service lines should be verified. This random verification is only required for those service lines of “unknown” material.

  • Written notification must be provided to the owner and occupant(s) of any building with a service line known, or assumed, to contain lead in any portion.

 Material Verification Process:

  1. Identify all potable water service lines of “unknown” material.

  2. Identify how many service lines should be physically verified.

    • Water supplies with fewer than 1,500 “unknown” service lines must verify at least 20% of the total number of “unknown” service lines.

    • Water supplies with 1,500 or more “unknown” service lines must physically verify enough lines to reach a 95% confidence level. See Appendix A in EGLE's guidance.

  3. Randomly select service lines for physical verification

    • From the list of “unknown” service lines identified in Step 1, randomly select enough service lines to at least meet the number requiring physical verification as determined in Step 2. In order introduce bias not the estimates, selection must not be based upon any specific criteria. See Appendix B in EGLE's guidance

  4. Create a tool for tracking records and materials during verification. See Appendix C in EGLE's guidance for an example.

  5. Conduct three- or four-point physical verification.

  6. Record results of physical verification in the tracking document created in Step 4.

  7. Evaluate results of the physical verification.

    • This representative, uniformly random sample of service line materials should be representative of service line materials from the portion(s) of the system from which the random set was selected.

    • Additional verification may be necessary if records are found to be unreliable. Additional work may be needed to build-out the inventory, notification to residents may be necessary, reporting to EGLE will be required, etc. Additional guidance on these steps will be provided by EGLE later.

The results of this verification, in combination with other available information, can be used to predict service line materials at other sites. Water supplies may need assistance with this process. EGLE will provide additional information in a separate guidance document.

We know these new requirements might seem daunting, but BlueConduit can help. These statistical best practices are what BlueConduit was founded on, and they are at the center of our work. We have used statistical modeling to inventory more than 500,000 pipes, impacting more than 1 million people. We can leverage this expertise so that your water system complies with the new CDSMI guidance and uses that information to generate actionable and actionable service line inventory and guide service line replacement program that saves time and money.

Click here to read EGLE’s press release or contact us with any questions. Detailed information about Michigan's Lead and Copper Rule can be found on EGLE's website.