The Final Rule on FGD Wastewater for Coal Fired Power is in. How did we get here and what does it mean???

Earlier this week, the US EPA finalized regulation that relaxed a 2015 rule regulating what coal-fired power producers could discharge to local waterways. For those of us that work in the Power industry, this is something we have been expecting for some time now. But for those who don’t spend time each day thinking about Power and how it’s produced, it may help to provide some background to understand what this new regulation is all about.

First off, the last time there was significant regulation on the wastewater discharge from a coal fired power plant was roughly 40 years ago. Since the 1980s, it had been up to local regulators to set the standard that power producers would have to abide by. As such, the rules typically changed from one power station to the next. This variability was addressed in 2015 when the EPA set out to address environmental concerns and align local permitting standards. Many power producers were caught flat footed and petitioned to repeal the new rules. After two years of effort, the EPA finally agreed to reconsider two key aspect of the 2015 rule. This impacted two of the largest components of the rule: 1) bottom ash (BA) transport water and 2) FGD wastewater. This came as welcome news to many coal-fired power plants, but since it was only a “reconsideration” it also introduced a new level of uncertainty for those power producers.

Fast forward to last year, and that uncertainty began to fade when the EPA published a draft set of rules for these BA systems and FGD waste streams. These rules were certainly a change from the 2015 regulation: They relaxed the standards around heavy metals such as selenium, arsenic, and mercury. It went even further to lay out several exceptions defined by utilization rates, timing of conversion to natural gas, or the timing or the overall closure of the facility. As much as these changes elicited a passionate response from both sides of the debate, it began to address the uncertainty for many power stations.

That background helps put this week’s announcement into perspective. But the decision leading to the announcement didn’t come overnight. Prior to submitting the 65-page final rule to the Federal Register for publication, the EPA took an extended period of time to collect feedback and to pressure test the data and assumptions behind the draft rule. But with that exercise completed, the real planning for the power stations waiting for direction can now begin to take action.

A few points about the key elements of EPA’s announcement jump out at me. First off, they have not changed the guidelines significantly from last year’s draft version. Sure, the numbers are a little tighter on selenium and arsenic, and they even relaxed the mercury standard, but for the most part the treatment required to meet these standards doesn’t change. Secondly, unless a plant is scheduled to close or convert to natural gas, most stations will need two basic processes. The first is a physical-chemical treatment to remove suspended solids, followed by a second biological reactor to further remove heavy metals, namely selenium, mercury and nitrate.

Both the draft and final rule call out exceptions for plants at both ends of the high flow and low utilization extremes. The high flow exception only applies to one plant on the east coast (you know who you are). But for the rest of the low flow or low utilization plants the threshold for low utilization shifted from the draft to the final form. In the draft form, low utilization was defined by less than 876,000 MWh/year in production. But in the final form, the low utilization category is defined by <10% capacity utilization rate. To put it in simple terms as the EPA did, this change means that roughly two-thirds of the plants that planned to avoid shut down or incur significant treatment expense, will now have to face some difficult decisions.

Admittedly as a water treater, I also took notice in one notable change from the 2015 rule, which was the definition of Best Available Technology (BAT) for the biological treatment. The EPA made it very clear in their final rule that a low hydraulic resonance time biological reactor is the best available technology to meet these new standards. This was clearly a nod to the more compact and economically efficient bioreactor that performed as well as if not better than its predecessor technology. In addition, given its compact modular design, it also has a significantly lower construction and installation price tag.

So that brings me to my “so what”. For those of you who are impacted by this rule, I would like to offer support and expertise. As the leader for the Power industry team for both Evoqua Water Technologies and Frontier Water Systems, I can tell you that we are sincerely empathetic as you face this challenge. And at the same time, we appreciate how your need is urgent and time is of the essence. So please do not hesitate to reach out if I can help connect you with our team of subject matter experts who have more experience in the application of these treatment systems than anyone else in the industry. I am confident that you will find our team to be a valuable resource and partner as you look to put your treatment strategies into place and finalize your required process changes.

Thank you.

Patrick Regan

Sr Director, Power Vertical for Evoqua/Frontier