Ammonia Criteria Implementation Workshop Findings Released

In April, the Water Environment Federation (Alexandria, Va.), Water Environment Research Foundation (Alexandria, Va.), the National Association of Clean Water Agencies (Washington, D.C.), and the Association of Clean Water Administrators (Washington, D.C.), released the executive summary of an October 2014 ammonia criteria implementation workshop. The organizations convened the workshop to identify data and information gaps regarding the implementation of the revised ammonia criteria and identify tools/projects needed to provide information that will fill these gaps and clarify options in the U.S. Environmental Protection Agency’s (EPA’s) flexibility guidance.

The key driver of this effort was the desire to propose a framework for how to implement the criteria based on a common set of principles, and provide clear guidance on a way to move forward on implementation of the criteria. The executive summary outlines this framework and recommendations from the workshop, which included representatives of municipalities, academics, and state and federal regulators.

Some of the key technical findings were about gaps in data and information. They included the need for

• more information on the role of use-attainability analysis and use of subcategorization/tiered aquatic life uses;
• a better definition of mixing-zone policies applicable to ammonia;
• additional studies on the fate of ammonia in receiving waters;
• potentially useful in-stream studies to evaluate discharger impact on viable mussel habitat; and
• better understanding of the consequences of pH, temperature, and upstream background concentration and parameter definitions/specifications.

From a management and policy perspective, the key findings were that the criteria can have major impact on small communities and may present complexities for larger systems that are in the process of upgrades to meet new requirements for nutrient control. However, the implementation of EPA’s new ammonia criteria provides a unique opportunity to

• introduce new permitting concepts and options to allow for more flexibility in meeting water quality standards,
• re-evaluate and prioritize ways to meet Clean Water Act goals in light of competing priorities, and
• discuss return on investment and affordability for smaller communities.