Induced Voltage
January 21, 2020
Lately, the power industry has been hearing of a new acronym around the halls, ELG. ELG stands for EFFLUENT LIMITATION GUIDELINES and under President Obama, the EPA set down rules and compliance requirements targeting Power Plants effluent discharge of wastewater to rivers, streams, and lakes1. The EPA regularly publishes updated guidelines for water pollution regulations for industrial and commercial facilities 2. These regulations apply to about 40,000 facilities that discharge directly to the nation’s waters. Additionally, the regulations apply to 129,000 facilities that discharge to municipal sewage treatment plants, and certain construction sites.
Traditionally, water discharged to public waterways has been strictly regulated. The new rule, however, tightened those long-standing requirements by establishing what technology was presently available and economically achievable. The EPA learned it’s foolish to make rules about removing waste products when the technology was unavailable or too expensive. The power plants don’t come up with these technologies on their own. Normally they are buying off the shelf items from industry leaders like Black and Veach, Hitachi, Wheelabrator, etc.
The Effluent Limitation Guidelines Planning Process
The EPA guides by the following goals:
- Restore and maintain the chemical, physical, and biological integrity of the nation’s waters; and
- Provide transparent decision making and involve stakeholders early and often during the planning process.
EPA considers four main factors when prioritizing existing ELGs for possible revision:
- The performance of applicable and demonstrated wastewater treatment technologies, process changes, and pollution prevention strategies to reduce pollutants in an industrial category’s wastewater;
- The costs (economic achievability) of demonstrated wastewater treatment technologies, process changes, and pollution prevention alternatives;
- The amount and types of pollutants in an industrial category’s discharge; and
- The opportunity to promote technological innovation or to eliminate inefficiencies or impediments to pollution prevention.
What This Means for Plants
What this means is that the EPA is mandating new discharge guidelines based on the affordable, available technology. Some of the available technology includes vacuum filters, settling tanks, biological filtration, ultrafiltration, and RO/DI to name a few. These technologies exist now and are relatively inexpensive. It also leaves the door open for new technologies as well. The EPA will study new technologies as they emerge. Then, the EPA will determine if it is economically feasible before mandating its use.
For instance, if you look at the FGD Wastewater as one wastewater stream from a powerplant, under the old rule FGD Wastewater could be impounded in a leachate pond such as a gypsum pond. The old rule forces the power industry to treat FGD Wastewater by chemical precipitation and biological treatment. This process removes mercury, arsenic, selenium, and NOx pollutants before the water discharges into a public waterway. There are six other water streams that fall under this rule: Flyash Transport Water, Bottom Ash Transport Water, Coal Combustion Residual (CCR) leachate, Flue Gas Mercury Control System Wastewater, Integrated Gasification Combined Cycle Wastewater, and Non-chemical Metal Cleaning Wastes3.
The Power Industry knows that they must keep a close eye on what is happening at the EPA. Even though the power industry has fought and won against some EPA mandated rules, states have stepped up to implement the rule regardless and sometimes with even more stringent setpoints. The Power Industry must evaluate the impact of these regulations and come up with a plan toAsh Recycling, meet the EPA or state-mandated rules. Being proactive in the reuse of wastewater streams can cut costs tremendously. These regulations are not going away and the EPA has built into the new program a means of tightening the requirements as new technologies become available.
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