In 2013 the U.S. Environmental Protection Agency (EPA) updated its freshwater ammonia criteria. In 2018 the General Assembly approved HB 1475 and SB 344, which were signed by the Governor on March 29, 2018, with an effective date of July 1, 2018 (2018 Va. Acts Chs. 510 and 511). This legislation dealt with the State Water Control Board’s (Board) adoption of EPA‘s recommended changes to the freshwater ammonia criteria, requiring that the Board include in such adoption a phased implementation program (PIP) consistent with the federal Clean Water Act. Including the PIP in the adoption of the new ammonia criteria was intended to address potential impacts on permitted dischargers across the state that will need extended compliance schedules and may be affected by fiscal stress.

HB 1475 and SB 344 also directed the Department of Environmental Quality (DEQ) to provide certain additional information to the General Assembly, no later than November 1, 2018. Specifically, HB 1475 and SB 344 asked DEQ to:

• Identify any other states that have adopted EPA’s 2013 Aquatic Life Ambient Water Quality Criteria for Ammonia as of July 1, 2018.

• Identify the specific procedures and practices for the implementation of the freshwater ammonia criteria that will both minimize the impact of the criteria on Virginia sewerage systems or other treatment works and be permissible under the federal Clean Water Act (33 U.S.C. § 1251 et seq.), including an opportunity to request consideration of alternative effluent limitations based on a demonstration by the permittee, acceptable to the Board, of the lack of appreciable harm from the discharge of ammonia to aquatic life that is present in the vicinity of the discharge or which should be present but for the discharge.

DEQ’s 2018 report, Flexibilities for Virginia’s Permitted Dischargers Implementing EPA’s 2013 Nationally Recommended Ammonia Criteria, addressed these requirements. The budget adopted during the 2019 General Assembly session included a requirement to update this report (HB 1700, 2019 Va. Acts Ch. 854, Item 366(J.)). Specifically, this budget language directed DEQ to “expand…[on the]…specific procedures and practices for ammonia criteria implementation to minimize their impact on Virginia sewerage systems or other treatment works, specifically by including all existing or potential permitting procedures and practices that are not prohibited by the Clean Water Act but which would provide relief to permitted dischargers." This report details those procedures and evaluates opportunities to minimize the impact on Virginia’s sewerage systems, while also protecting water quality.

There are numerous considerations taken into account by DEQ permit writers in establishing appropriate effluent limitations for ammonia. These considerations include discharge flow, stream flow, in-stream mixing conditions, and the pH and temperature of both the discharge and the receiving stream. DEQ formed an internal implementation workgroup to evaluate these and other factors related specifically to the proposed nationally recommended freshwater ammonia criteria. Both the federal Clean Water Act and federal regulations must be considered in evaluating and determining the appropriate procedures. The internal workgroup is developing draft guidance for ammonia, which will supersede existing effluent limitation development guidance specific to ammonia and is expected to provide some relief to permitted dischargers as will be discussed more fully in this report. This internal workgroup is tasked with establishing ammonia criteria implementation procedures that prevent instream toxicity as well as minimize the impact to the regulated community to the extent possible under the federal Clean Water Act. Because of the complexities involved in evaluating reasonable potential and establishing effluent limits, this is an inherently technically complex process. DEQ expects to release new guidance for public comment by the end of 2019.