Reducing Nitrification Risks Through Voluntary Collaboration Between Drinking Water Wholesalers and Consecutive Systems

The U.S. Environmental Protection Agency (USEPA) is currently revising the Microbial and Disinfection Byproducts (MDBP) Rules as part of its third Six-Year Review. These revisions are expected to affect wholesale and consecutive drinking water systems, particularly those that use chloramines and must manage nitrification challenges.

To prepare utilities for these upcoming regulatory changes, this project aims to develop practical, user-friendly guidelines for preventing and mitigating nitrification in distribution systems.

The project objectives are to:

• Define the roles and responsibilities of wholesale and consecutive systems, including regulatory, water quality, and operational requirements.
• Establish best practices for effective collaboration between wholesalers and consecutive systems.
• Promote improved communication and develop model agreements to strengthen partnerships across systems.
• Provide guidance on nitrification management, including prevention, early detection, and response strategies for both low-level and advanced nitrification events.

These guidelines will help utilities improve water quality, strengthen regulatory compliance, and enhance public health protection through better nitrification control.