Consumers Energy Comments on Effluent Limitations Guidelines, Standards for Steam Electric Power Generating Point Source Category
- Jan 24, 2020 1:34 pm GMT
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WASHINGTON, Jan. 22 -- Rachel Proctor, senior engineer of Consumers Energy Co., Jackson, Michigan, has issued a public comment on the Environmental Protection Agency's proposed rule entitled "Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category". The comment was written on Jan. 17, 2020, and posted on Jan. 21, 2020:
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Consumers Energy Company (CE) appreciates the opportunity to comment on the Environmental Protection Agency's (EPA) Notice of Proposed Rulemaking (NOPR) published in the Federal Register on November 22, 2019, "Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category" (Docket ID No. EPA-HQ-OW-2009-0819). CE generally supports the NOPR with certain modifications and clarifications discussed below.
I. Statement of Interest
CE is a public electric and natural gas utility located in the Midcontinent Independent System Operator (MISO) footprint, serving over 1.8 million residential, commercial, and industrial customers. It is one of the two largest public utilities in the lower peninsula of Michigan. The NOPR impacts CE because it owns and operates five coal-fired units generating bottom ash transport water. Two of the five units will be retired before 2028. Under the proposed rule, the remaining three units will require retrofit of their bottom ash transport water systems to achieve the proposed high recycle rate. Thus, CE has a significant interest in the outcome of this NOPR, and CE's interests will not be adequately represented by any other party.
CE generally supports the NOPR with certain modifications including amending the definition "retired from service" and clarification of Primary Active Wetted Bottom Ash System Volume Calculation.
A. Support for the Subcategory for Boilers Retiring by 2028
CE supports the proposed subcategory for boilers retiring by Dec. 31, 2028. CE plans to retire its D.E. Karn (Karn) Units 1 and 2, both of which are coal-fired, in 2023. This plan has been approved in our recent Integrated Resource Plan (IRP) filing with the Michigan Public Service Commission (MPSC) and has received MISO's approval to suspend Karn Units 1 and 2 operations without the need for the units to be designated as a System Support Resource (SSR). Allowing CE to avoid additional compliance costs under the NOPR's eventual final rule protects our customers from significant costs that can be reallocated to other investments, such as renewable energy development, energy efficiency measures, ensuring reliable electric service. We estimate that, absent the retirement exemption, CE would need to spend approximately $31 million to bring the Karn Units 1 and 2 into compliance with the rule.
The proposed subcategory also supports the EPA's goal of aligning with the Coal Combustion Residual (CCR) rule. Currently all unlined coal ash surface impoundments/1 operated by CE, have provided notice to initiate closure and are following federal and state timelines to complete closure. At Karn all bottom ash transport water is currently sent to a CCR-compliant surface impoundment, with discharges regulated under the site's National Pollutant Discharge Elimination System (NPDES) Permit. By maintaining the proposed subcategory, the site can continue sending bottom ash transport water to CCR-compliant surface impoundments until retirement in 2023 and eliminate unnecessary costs to utility customers.
B. Support for End of Life Decommissioning with Modification
The NOPR revises the term "transport water" to "...any wastewater that is used to convey fly ash, bottom ash, or economizer ash from the ash collection or storage equipment, or boiler, and has direct contact with the ash. Transport water does not include low volume, short duration discharges of wastewater from minor leaks (e.g., leaks from valve packing, pipe flanges, or piping), minor maintenance events (e.g., replacement of valves or pipe sections), cleaning FGD paste transportation piping, wastewater present in equipment when a facility is retired from service, or maintenance purge water."/2
The exemption of "wastewater present in equipment when a facility is retired from service" appears to address bottom ash transport water remaining on a site at decommissioning. While CE supports an end-oflife decommissioning exemption, this exemption should not be limited to wastewater present only in "equipment." Rather, the definition should explicitly include other site locations containing similar wastewater at the time of a facility's retirement. For example, equipment should include legacy bottom ash transport water present in surface impoundments and clarifying basins, as these are integral units used in settling out bottom ash and, under the NOPR, are used as a basis for BAT effluent limitations for units retiring by 2028. The rule should allow a NPDES permittee to dewater end of life equipment and legacy storage ponds, utilizing appropriate best management practices and meeting all permit limits.
The NOPR adds the term "retired from service" to mean:
"...the owner or operator of a boiler no longer has, or is no longer required to have, the necessary permission through a permit, license, or other legally applicable form of permission to conduct electricity generation activities under Federal, state, or local law, irrespective of whether the owner and operator is subject to this part."/3
CE recommends amending this definition. It is not uncommon for generating stations, comprised of multiple units (i.e., boilers), to retire those units independently, and at different times. The proposed definition does not adequately address the fact that an owner or operator may retain permits or licenses for a site, while also retiring individual or multiple units at that site. For example, at our Karn site, Units 1 and 2 are coal-fired, baseload units while Units 3 and 4 are oil-fired, peaking units. As mentioned above, Units 1 and 2 will be retired in 2023, but Units 3 and 4 will continue to operate past 2028. The site will need to retain its license, permits, etc. to generate electricity after Units 1 and 2 retire. CE recommends that a certification statement signed by a "responsible corporate officer"/4 is sufficient for documenting when electric generation has ceased./5
D. Clarification of Primary Active Wetted Bottom Ash System Volume Calculation
CE seeks further clarification of the 30-day rolling average for transport water discharge of ten percent of the primary active wetted bottom ash system volume. The ten percent purge volume is based on the "primary active wetted bottom ash system volume." EPA defines this proposed term as the "...maximum volumetric capacity of bottom ash transport water in all piping (including recirculation piping) and primary tanks of a wet bottom ash system, excluding the volumes of installed spares, redundancies, maintenance tanks, other secondary bottom ash system equipment, and non-bottom ash transport systems that may direct process water to the bottom ash system as certified to in paragraph 423.19(c)."/6
CE's J.H. Campbell Units 1 - 3 site uses a concrete tank-based handling system for wastewater treatment and settling of bottom ash from transport water for all three units. As mentioned previously, retrofits will be needed to convert to a high recycle rate system under this proposed rule. The concrete tank-based handling system is currently designed with two primary tanks, two secondary tanks, and one tertiary tank all interconnected as part of gravity settling prior to discharge. Based on this proposed definition, J. H. Campbell's secondary and tertiary tanks would not be included in the primary active wetted bottom ash system volume. While most gravity settling in the bottom ash tank system occurs in the primary tank, the secondary tanks provide additional hydraulic residence time to remove any residual ash, as well as provide for additional treatment, such as potential polymer addition. These secondary tanks will be an integral part of maintaining water balance within the high recycle rate system and as such, they should be included in the definition of "primary active wetted bottom ash system volume." If they are not, the volume of purge allowed could potentially limit the ability to maintain water balance and water quality within the system.
In addition, it is not uncommon for sites with multiple units to retire individual units at different times. At CE's J.H. Campbell site, Units 1 and 2 are scheduled to shut down in 2031, nearly a decade before Unit 3's retirement in 2040. However, all 3 units currently share a bottom ash treatment system, and thus likely share a combined high recycle rate system under the NOPR. Consumers Energy is concerned that the proposed rulemaking does not address how the "primary active wetted bottom ash system volume" and 10 percent purge volume should be adjusted, if at all, when the water volume required for ash handling changes due to partial unit retirement. CE requests EPA clarify that partial unit retirements does not change the calculation of the "primary active wetted bottom ash system volume," or associated 10 percent purge volume, made when the high recycle rate system is initially installed. The contrary situation - requiring the volumes to be adjusted when a unit retires - may create substantial retrofitting costs to the high recycle rate system. Thus, CE recommends that the primary active wetted bottom ash system volume remain the same after a unit(c) retires from a shared high recycle rate system.
III. Conclusion CE appreciates the opportunity to provide comments to EPA on its "Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category" (Docket ID No. EPA-HQ-OW-2009- 0819). Questions may be directed to Rachel Proctor email@example.comT), (517) 788-1429.
Rachel Proctor, P.E,
Consumers Energy Company
1945 W, Parnall Rd
Jackson, Ml 49201
Phone: (517) 788-1429
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1 "Unlined" meaning in this context that the surface impoundment must have at least a single composite liner system.
2 84 FR 64672, 40 CFR 423.11(p).
3 84 FR 64672, 40 CFR 423.11(w).
4 40 C.F.R. Sec. 122.22(a)(1) ("a responsible corporate officer" means: "(i) A president, secretary, treasurer, or vice president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decisionmaking functions for the corporation or (ii) the manager of one or more manufacturing, production, or operating facilities, provided the manager is authorized to make management decisions which govern the operation of the regulated facility...."
5 Certification statements by a responsible corporate officer under the NPDES permitting program (40 CFR Part 122.22) are legally binding and sufficient for submitting documents such as a permit application (40 CFR Part 122.21).
6 84 FR 64672, 40 CFR 423.11(aa)
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The proposed rule can be viewed at:https://beta.regulations.gov/document/EPA-HQ-OW-2009-0819-7106
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