Using a materials evaluation that represents current conditions in the community,
adequately justifying any use of Tier 2 or Tier 3 LCR sample sites, rather than Tier 1 sites for LCR first-draw tap samples, and
identifying and addressing the root cause of any action level exceedance.
The memorandum also:
Strongly recommends that water systems document periodic updates to LCR materials evaluations and document how information is obtained to update the inventory.
Advises states to consider a water system’s (1) corrosion control treatment and historical LCR performance and (2) technical, managerial, and financial capacity before allowing it to return to triennial monitoring.
This memorandum is the latest in a series of actions by EPA to improve implementation of the current LCR while the agency develops a revised rule. EPA plans to propose the LCR Long-Term in 2017.