Tom Neltner, J.D., Chemicals Policy Director
The Association of State Drinking Water Administrators (ASDWA) released a new white paper to help states and utilities develop more useful inventories of lead service lines (LSLs). The paper builds on guidance the organization issued in August 2019. ASDWA partnered with BlueConduit to leverage that firm’s experience developing a statistical model for Flint, Michigan that accurately predicted which service lines were made of lead, galvanized steel, plastic or copper.
The guidance is timely as EPA prepares to finalize its Lead and Copper Rule revisions. We anticipate those revisions will require utilities to develop – and make public – inventories that identify the location of each service line made of lead or when the material is unknown and may be lead. Utilities would also be required to notify customers annually if they have a lead or unknown service line. Customers who buy a home and open a new water account would also be notified in the first bill.
The ASDWA/BlueConduit white paper encourages utilities to use five principles to best characterize the uncertainty in their inventories:
- Ensuring clean data management and organization;
- Not accepting all historical records as truth;
- Conducting a representative randomized sample of unverified service lines;
- Being transparent in public outreach and reproducibility; and
- Demonstrating accuracy on “hold-out sample.”