Last fall, the United States Environmental Protection Agency (EPA) finalized a rule that sets the first federal limits on the levels of toxic metals in power plant effluents. The rule will likely affect about 12 percent of steam electric power plants that must reduce the levels of metals, nutrients and other pollutants by 1.4 billion pounds. The overlap of these new wastewater regulations and recently passed Coal Combustion Residual (CCR) regulations poses significant challenges for power plants.
The Cost of Implementation
The EPA estimates it will cost $480 million industrywide to come into compliance with effluent limitation guidelines (ELGs). But some — including representatives from the National Rural Electric Cooperative Association — believe that number is too low. A recent special report from Bloomberg BNA asserts high capital costs will place too high a burden on small- and medium-sized power plants to meet the EPA’s new regulations.
The issue of power plant wastewater goes back to the Clean Air Act Amendments of 1990, when technologies for scrubbing the pollutants out of exhaust gases led to an increase in those pollutants in wastewater. The new rule provides ELGs — national standards for how this wastewater must be managed or treated before it can be discharged to surface waters.
Overlapping ELG and CCR Regulations
Complicating the situation is the timing of an EPA regulation covering coal combustion residuals (CCR), which went into effect in October 2015. CCRs are fly and bottom ash, boiler slag or flue gas desulfurization (FGD) materials generated by coal-fired power plants. This rule change sets standards for where and how ponds and landfills are built, operating them, monitoring their performance and closing them when full. The regulation is expected to lead to the closure of a number of CCR ponds and landfills.
ELGs and CCRs are intimately connected. As coal-fired power plants take action to meet the ELG rule, they must also consider the CCR requirements. For example, if ash pond use is halted because of the ELG, then the pond must be closed under the CCR rule within a specific amount of time and must meet other CCR requirements. Burns & McDonnell can help you develop solutions for both ash handling and wastewater treatment, but these systems take time to plan and implement.
Developing a Long-Term Plan for Compliance
With the EPA tightening up in both areas, the idea that power plants will have to do nothing is unlikely. If not already in progress, operators should make it a priority to develop a compliance strategy that considers both the CCR and ELG. One step in that process is converting to dry handling of fly ash and bottom ash — a process we’ve helped operators across the country implement.
So, what’s next? Where do you use water? How are you going to handle a dry process? What does your water look like when your ash pond goes away? Answering these questions can provide a good foundation for compliance.
Understanding your plant’s water budget is the first step. If needed, our team has the equipment in house to design and conduct a flow metering program at your plant to document your flows. A valuable but sometimes overlooked tactic is the development of a strong water management program, cutting water use by doing everything from fixing leaky pumps to tightening up operational processes. A surprising amount of water can be lost through pump seals and small process leaks. The less water you use, the less you have to treat and discharge. Because water treatment costs are driven by the flow rate, tightening the water budget can pay off big in capital cost savings.
The next step is understanding what you need to do to comply. Are you only impacted by the ELG requirements, or do you also have local discharge requirements — such as water quality based effluent limits (WQBELs) — to contend with? Consultants with extensive permitting experience can be a significant asset in helping your plant reach compliance as cost effectively as possible.
A good water balance is vital. It’s a tool to predict the impact of changes in plant processes on water use and on effluent quality. If paired with monitoring data, the water balance can become a mass balance that will estimate the final concentration of regulated constituents in the plant effluent, following dry ash conversion and pond closure. This, in turn, will show whether wastewater treatment systems are needed for any of the “leftover” streams, and help to size any new equipment that is needed.
If treatment is needed, tactics to achieve compliance might include a mix of pond-based systems and tank-based systems, including flue gas desulfurization (FGD) wastewater treatment using both physical/chemical and biological systems. Some may choose to install evaporative treatment or eliminate all FGD wastewater by another method in order to qualify for extra time to meet the compliance deadline. It sounds complicated and it can be. The changes required by both recent EPA regulations are extensive.
We’re committed to helping our clients simplify the process by helping define treatment goals and outlining a plan for moving forward.
What do you think? Are these regulations too heavy a burden for small to midsize power plants? Share your thoughts in the comments.