“Flyash Pond and Wastewater Treatment Issues" was the Hot Topic Hour on Thursday, May 3 and Friday, May 4, 2012

Eight speakers addressed the very potentially expensive requirements for addressing this subject. The conclusion was that there is great uncertainty. Some beneficial reuse projects are delayed until certainty is established. Several different regulations could determine the outcome.

Presenting on Thursday, May 3, 2012

John N. Ward, President of John Ward, Inc representing the American Coal Ash Association (ACAA) provided an update on coal ash regulatory and legislative issues. Three and a half years have passed since a coal ash impoundment failure in Tennessee prompted the U.S. Environmental Protection Agency to initiate rulemaking activities for new coal ash disposal regulations. With no end in sight for the rulemaking, Congress is getting involved and legislation creating new disposal regulations is now the subject of a Transportation Bill conference committee negotiation. Meanwhile, lawsuits against the EPA, new EPA-led risk evaluations of coal ash beneficial use, and an expected Notice of Data Availability related to Steam Effluent Generating Guidelines data are combining to further complicate the regulatory outlook.

James Ballan, Manager of SCM (Supplementary Cementitious Materials) at FLSmidth, Inc, discussed processes for coal ash beneficiation. For many years coal ash has been in use as a cement additive, soil stabilizer and filler for underground voids such as sink holes and mines.  All of the discussion about regulating CCRs as hazardous waste has attached a stigma to the beneficial re-use. FLS is using its roaster concept to create a system to vaporize the metals from the flyash and eliminate concerns about use or disposal. In the question period there was a discussion of potential recovery of valuable metals as part of the separation process. FLS is looking into this potential as well.

Naomi Levy, Lead Industrial Engineer at Infilco-Degremont, Inc, described treatment options for both the flyash and the flyash pond leachate. Flyash is one of the many byproducts generated in power plant’s operations as a result of the combustion of coal. It contains all the non-combustible minerals that were deposited with the coal and is highly variable. In many places, this residue is being collected in ash ponds.  Unless treated or reused, it would stay inside the structure “forever,” potentially being a candidate for a disastrous spill or contributing to the contamination of the water receiving body. Infilco Degremont uses a very compact treatment system which includes mixing and clarification in one vessel.

Douglas J. Dahlberg, P.E. at Sargent & Lundy LLC, discussed how the proposed U.S. EPA coal combustion residuals regulations will impact the power plant and the bottom line. The more recent Oak Creek, Wisconsin generating facility ash-bluff collapse reminded the regulatory agencies of the potential problems associated with ash disposal sites. The critical questions are “What’s this going to cost and how will it affect your power plant’s bottom line?”  With proposed rules technically similar to the existing Subtitle D municipal solid waste disposal regulations, CCRs handling and disposal unit costs can be estimated by considering differences and similarities between municipal solid waste and CCRs.

Presenting on Friday, May 4, 2012

Nick Nelson, Environmental Specialist at Barr Engineering Company, explained all the investigations, permits and challenges to meeting a suite of regulations which are still unclear. He recommended that utilities do pre-project investigations and be in a position to move forward. He cautioned that some of the regulatory processes can take years. So there is definitely a challenge in meeting potential deadlines.

Dr. David Mazyck, Carbonxt talked about a unique activated carbon product which can be added after the conventional wastewater treatment. It can remove selenium. Tests to date have shown removal efficiencies high enough to meet proposed standards

Dennis Fink, Environmental Engineer and Sr. Project Manager, Industrial Systems at CH₂M Hill, discussed CH₂M Hill’s work with power plants to address pressures to close ash ponds. The approach described in this presentation to eliminate ash ponds includes a combination of:  eliminating wastewater streams, segregating streams that have stringent regulatory requirements or that adversely affect reuse (total dissolved solids), and treating remaining high volume/easily treatable wastewater for reuse or discharge. He recommended an approach which looks first at the least expensive approaches to meet the requirements and progressively moves to the more expensive ones including zero liquid discharge if the less expensive approaches are not adequate.

Ari Schoen Lewis, Health Scientist at Gradient Corporation, discussed “Human Health Risk Assessment and the Regulation of Coal Combustion Residues (CCRs).”  In support of the Proposed Rule to regulate CCRs, U.S. EPA has published several assessments on the potential human and ecological risks associated with various coal ash disposal practices. Ari listed the risks associated with surface impoundments and how this information was used in the cost-benefit analysis to distinguish among different regulatory options. Ari also explained how human health risk analysis will be important to address future safety concerns associated with disposal and beneficial use of CCR, and the importance of emerging toxicological assessments of the chemical constituents in CCRs (e.g., arsenic, cobalt, chromium).

The Bios, Abstracts and Photos information is linked below.

Utility E-Alert/2012/BIOS, ABSTRACTS, PHOTOS - MAY 3-4, 2012.htm