Effluent Limitations Guidelines (ELGs), Part I: Compliance Check

The US Environmental Protection Agency (EPA) has issued new regulatory standards for steam electric power generating stations known as the Effluent Limitations Guidelines (ELGs). The ELGs provide stricter regulations on industrial wastewater discharges from power stations. GAI’s Scott Quinlan, PE joins us as a guest blogger to discuss the most recent guidelines and how clients can plan to be in compliance.

The rule sets the first federal limits on the levels of toxic metals in wastewater that can be discharged from power plants, based on technological improvements in the steam electric power industry over the last three decades.

To remain operational, it is critical that coal fired power plants comply with the final ruling of the ELGs, published on September 20, 2015.

The rule sets the first federal limits on the levels of toxic metals in wastewater that can be discharged from power plants, based on technological improvements in the steam electric power industry over the last three decades.

New technologies for generating electric power and the widespread implementation of air pollution controls over the last 30 years have altered existing wastewater streams or created new wastewater streams at many power plants, particularly coal-fired plants. The 2015 rule addresses these changes in the industry. The final rule sets new or additional requirements for wastewater streams from the following processes and byproducts:

  • Flue gas desulfurization
  • Fly ash
  • Bottom ash
  • Flue gas mercury control
  • Gasification of fuels such as coal and petroleum coke

The ELG rule follows closely in hand with the Coal Combustion Residual (CCR) rule that was published in December 2014.

GAI’s wastewater engineers are highly skilled at developing strategies for our clients to meet these regulations. Water Balance evaluation and structuring strategic water reuse and recycling is a cost effective and desirable solution for many of our clients to achieve compliance with both the ELG and CCR regulations.

One approach that GAI currently evaluates for its appropriateness with our clients is zero liquid discharge (ZLD) for Flue Gas Desulfurization (FGD) wastewater. ZLD uses heat and vapor compression to evaporate the wastewater and concentrate the salts so high that they become a landfill appropriate solid. The evaporated water is later condensed and reused as FGD makeup water. Reverse Osmosis (RO) with proper pretreatment can drastically reduce the size and cost of thermal evaporation. Permeate of the RO system can be used as FGD makeup. The advantage is that there is no longer a wastewater discharge and any further regulations for FGD wastewater will no longer be applicable. This is one of many approaches that GAI considers in the full spectrum of wastewater treatment for our clients.

For questions on the ELGs, contact Scott Quinlan, PE, Senior Engineering Manager, at 412.399.5385.

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