On August 31, 2020, the EPA Administrator signed the final revisions to the Effluent Guidelines and Standards for the Steam Electric Power Generating Point Source Category. These revisions culminated from legal challenges to the 2015 rulemaking and U.S. Environmental Protection Agency's postponement of the original compliance dates to November 2020. The Steam Electric Power Generating Effluent Guidelines and Standards (40 CFR 423) regulate wastewater discharges from flue gas desulfurization (FGD), flue gas mercury control (FGMC), fly ash (FA) and bottom ash (BA) transport, and gasification wastewaters within the fossil fuel and nuclear electric power generation sector. The 2020 rule revisions modify the voluntary incentive program and the limits for the flue gas desulfurization wastewater and bottom ash transport water waste stream but limits for other waste streams from the 2015 rule remain unchanged.
In the 2020 rule, EPA introduced three new subcategories namely 1) high FGD flow units, 2) low utilization units, and 3) units that will cease coal combustion by 2028 with the goal of establishing tailored and less burdensome requirements for each subcategory.
In addition to the introduction of subcategories, there are two significant revisions in the rule. First, the effluent limitation for BA transport water is now based on a high recycle rate system with site-specific BA purge water not exceeding 10% as opposed to a zero-discharge system. Second, EPA proposed more stringent effluent limits for nitrate/nitrite and mercury and less stringent limits for arsenic and selenium. In addition, EPA did not reestablish Total Suspended Solids (TSS) limitations for any existing subcategories after the 2015 rule TSS limits were vacated by the U.S. Court of Appeals for the Fifth Circuit. Table 1 presents an overview of the requirements including the new subcategories and how the requirements compare to the 2015 rule.
Additionally, the final rule includes revisions to the voluntary incentives program (VIP) established in the original 2015 rule. EPA changed the technology basis for the VIP from thermal filtration to membrane filtration technology. With that change, EPA is providing plants that adopt additional process changes and controls that achieve more stringent limitations on mercury, arsenic, selenium, nitrate/nitrite, bromide, and total suspended solids in FGD wastewater until December 31, 2028 to meet the new standards and limitations. Furthermore, EPA included new limits for bromide and nitrate/nitrite in the VIP and strengthened the mercury limit; however, it made the effluent limits for arsenic, selenium, and TDS less stringent. Table 2 below summarizes the final effluent limits for FGD wastewater from existing sources and how it compares to the limits from 2015 rule.
In accordance with rule provisions, all new effluent limitations will be incorporated into the wastewater discharge permits (i.e., NPDES permits) by the permitting authorities. Under the 2017 postponement rule, the “as soon as possible” date for compliance with the new effluent limitations for the FGD wastewater was postponed to November 1, 2020. In the 2020 rule, EPA is finalizing the “as soon as possible” compliance date for FGD wastewater stream and BA transport water to one year after publication in the federal register (i.e., fourth quarter 2021.) The 2015 rule also included specific factors that the permitting authority must consider in determining the “as soon as possible” date and EPA is not revising this aspect of the rule. Lastly, EPA is extending the “no later than” date for FGD and BA transport wastewater streams from December 31, 2023 to December 31, 2025.
Trinity is well versed in the power industry and is available to answer any of your questions. If you need assistance evaluating the new rule changes and the potential impacts to your facility, please contact your local Trinity office at 800.229.6655.