Attachment to Part B Comments of Earthjustice et al., EPA-HQ-OLEM-2019-0173 Assessment Monitoring Outcomes (2019) EPA’s Final Coal Ash Rule, 40 C.F.R. § 257.94(e)(3), requires the owners or operators of existing Coal Combustion Residuals (CCR) units to prepare a notification stating that an assessment monitoring program has been established if it is determined that a statistically significant increase over background levels for one or more of the constituents listed in appendix III of the CCR Rule has occurred, without an alleged alternate source demonstration. This table identifies the CCR surface impoundments known to be in assessment monitoring and required to identify any constituent(s) in appendix IV detected at statistically significant levels (SSL) above groundwater protection standards and post notice of the assessment monitoring outcome per 40 C.F.R. § 257.95. The table includes the surface impoundments that were required to post notice of appendix IV exceedance(s), as applicable, or elected to do so as of the time of this assessment monitoring outcomes review (summer 2019). To the best of our knowledge, neither EPA nor any other entity has attempted to assemble this information and make it public. Note that this document is not confirming that the industry notifications or assessments were compliant with the CCR Rule or that additional units may not belong on this list. Assessment Monitoring Outcome # of Surface Impoundments Appendix IV Exceedance(s) 214 Appendix IV Exceedance(s), alleged Alternate Source Demonstration 16 No Appendix IV Exceedance Reported 64 Total 294 Name of Plant Appendix IV Operator CCR Unit or Site Exceedance(s) Healy Power Plant GVEA AK Unit 1 Ash Pond Yes Healy Power Plant GVEA AK Unit 1 Emergency Overflow Pond Yes Healy Power Plant GVEA AK Unit 1 Recirculating Pond Yes Charles R. Lowman Power Power South Energy Cooperative AL Flue-Gas Desulfurization Waste (FGD) Pond Yes Plant Charles R. Lowman Power Power South Energy Cooperative AL Unit #1 Ash Pond Yes Plant Charles R. Lowman Power Power South Energy Cooperative AL Unit #2/3 Ash Pond Yes Plant Colbert Fossil Plant Tennessee Valley Authority AL Ash Disposal Area 4 CCR Unit Yes E.C. Gaston Steam Plant Alabama Power AL Plant Gaston Gypsum Pond Yes, alleged ASD E.C. Gaston Steam Plant Alabama Power AL Plant Gaston Ash Pond Yes James H. Miller, Jr., Electric Alabama Power AL Plant Miller Ash Pond Yes Generating Plant James M. Barry Electric Alabama Power AL Gypsum Storage Pond No Generating Plant James M. Barry Electric Alabama Power AL Ash Pond Yes Generating Plant Plant Greene County Alabama Power AL Ash Pond Yes William C. Gorgas Electric Alabama Power AL Ash Pond Yes Generating Plant William C. Gorgas Electric Alabama Power AL Gypsum Pond Yes Generating Plant Arizona Public Service Electric Cholla Power Plant AZ SEDI (Sedimentation Pond, Cooling Pond Dam) No Company Arizona Public Service Electric Cholla Power Plant AZ Bottom Ash Pond Yes Company Arizona Public Service Electric Cholla Power Plant AZ Fly Ash Pond Yes Company Cherokee Station Xcel Energy CO Center Ash Pond No Cherokee Station Xcel Energy CO East Ash Pond No Cherokee Station Xcel Energy CO West Ash Pond No Rawhide Energy Station Platte River Power Authority CO Bottom Ash Transfer Impoundment 1 Yes Rawhide Energy Station Platte River Power Authority CO Bottom Ash Transfer Impoundment 2 Yes Valmont Station Xcel Energy CO CCR Impoundment 3A Yes Valmont Station Xcel Energy CO CCR Impoundment 3B Yes Deerhaven Generating Gainesville Regional Utilities FL Surface Impoundment System No Station Plant Crist Gulf Power FL Gypsum Storage Area Yes Plant Smith Gulf Power FL CCR Ash Pond Yes Plant Bowen Georgia Power Company GA Ash Pond 1 Yes Plant Crisp Crisp County Power Commission GA Ash Pond No Plant Hammond Georgia Power Company GA Ash Pond 1 Yes Plant Hammond Georgia Power Company GA Ash Pond 2 Yes Plant McIntosh Georgia Power Company GA Ash Pond 1 Yes Plant Scherer Georgia Power Company GA Ash Pond 1 Yes, alleged ASD Plant Wansley Georgia Power Company GA Ash Pond Yes, alleged ASD Plant Yates Georgia Power Company GA Ash Pond 2 No Plant Yates Georgia Power Company GA Ash Pond 3 Yes Plant Yates Georgia Power Company GA Ash Pond B Yes Plant Yates Georgia Power Company GA Ash Pond B' Yes Burlington Generating Interstate Power and Light IA Ash Seal Pond Yes Station Company Burlington Generating Interstate Power and Light IA Economizer Ash Pond Yes Station Company Burlington Generating Interstate Power and Light IA Main Ash Pond Yes Station Company Burlington Generating Interstate Power and Light IA Upper Ash Pond Yes Station Company Interstate Power and Light Lansing Generating Station IA Upper Ash Pond Yes Company Louisa Generating Station MidAmerican Energy Co. IA Impoundment No Neal North Energy Center MidAmerican Energy Co. IA Impoundment 3B No Interstate Power and Light Ottumwa Generating Station IA OGS Ash Pond Yes Company Prairie Creek Generating Interstate Power and Light IA PCS Discharge Pond Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 1 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 2 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 3 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 4 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 5 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 6 Yes Station Company Prairie Creek Generating Interstate Power and Light IA PCS Pond 7 Yes Station Company Walter Scott Jr. Energy MidAmerican Energy Co. IA South Surface Impoundment No Center Baldwin Energy Complex Luminant (formerly Dynegy Inc.) IL Baldwin Bottom Ash Pond Yes Baldwin Energy Complex Luminant (formerly Dynegy Inc.) IL East Fly Ash Pond Yes Baldwin Energy Complex Luminant (formerly Dynegy Inc.) IL Old East Fly Ash Pond Yes Baldwin Energy Complex Luminant (formerly Dynegy Inc.) IL West Fly Ash Pond Yes Coffeen Power Station Luminant (formerly Dynegy Inc.) IL Coffeen Ash Pond No. 2 Yes Coffeen Power Station Luminant (formerly Dynegy Inc.) IL Coffeen Ash Pond No. 1 Yes Coffeen Power Station Luminant (formerly Dynegy Inc.) IL Coffeen GMF Recycle Pond None reported Dallman Power Generating City Water, Light and Power IL Dallman Ash Pond Yes Station Dallman Power Generating City Water, Light and Power IL Lakeside Ash Pond Yes Station 2 Edwards Power Station Luminant (formerly Dynegy Inc.) IL Edwards Ash Pond None reported Havana Power Station Luminant (formerly Dynegy Inc.) IL Havana East Ash Pond (Cells 1, 2, 3, and 4) None reported Hennepin Power Station Luminant (formerly Dynegy Inc.) IL Hennepin Old West Polishing Pond Yes Henepin Old West Ash Pond (Pond No. 1 and Hennepin Power Station Luminant (formerly Dynegy Inc.) IL Yes Pond No. 3) Hennepin Power Station Luminant (formerly Dynegy Inc.) IL Hennepin Ash Pond No. 2 Yes Hennepin Power Station Luminant (formerly Dynegy Inc.) IL Hennepin East Ash Pond None reported Joppa Power Station Luminant (formerly Dynegy Inc.) IL Joppa East Ash Pond None reported Kincaid Power Station Luminant (formerly Dynegy Inc.) IL Ash Pond None reported Marion Power Plant SIPC IL Emery Holding Pond Yes Powerton Generating Station NRG IL Ash By-pass Basin Yes Powerton Generating Station NRG IL Ash Surge Basin Yes Wood River Power Station Luminant (formerly Dynegy Inc.) IL Wood River West Ash Pond 2W None reported Wood River Power Station Luminant (formerly Dynegy Inc.) IL Wood River West Ash Pond 2E None reported Wood River Power Station Luminant (formerly Dynegy Inc.) IL Wood River West Ash Pond 1 None reported Wood River Power Station Luminant (formerly Dynegy Inc.) IL Wood River Primary East Ash Pond Yes A.B. Brown Generating SIGECO, dba Vectren Power Supply IN Ash Pond Yes Station Northern Indiana Public Service Bailly Generating Station IN Bailly Primary 1 Yes Company Northern Indiana Public Service Bailly Generating Station IN Bailly Primary 2 Yes Company Northern Indiana Public Service Bailly Generating Station IN Bailly Secondary 1 Yes Company Northern Indiana Public Service Bailly Generating Station IN Bailly Boiler Slag Pond No Company Cayuga Generating Station Duke Energy IN Secondary Ash Settling Pond Yes Cayuga Generating Station Duke Energy IN Lined Ash Disposal Area Yes Cayuga Generating Station Duke Energy IN Primary Ash Settling Pond Yes Clifty Creek Station Indiana-Kentucky Electric Corp. IN Landfill Runoff Collection Pond Yes Eagle Valley Generating Indianapolis Power & Light IN Pond A Yes Station Company Eagle Valley Generating Indianapolis Power & Light IN Pond B Yes Station Company Eagle Valley Generating Indianapolis Power & Light IN Pond C Yes Station Company F.B. Culley Generating Station SIGECO, dba Vectren Power Supply IN East Ash Pond Yes Gallagher Generating Station Duke Energy IN Ash Pond A Yes Gallagher Generating Station Duke Energy IN Primary Pond Yes Gibson Generating Station Duke Energy IN North Ash Pond Yes Gibson Generating Station Duke Energy IN North Settling Basin Yes Harding Street Generating Indianapolis Power & Light IN Pond 1 Yes Station Company Harding Street Generating Indianapolis Power & Light IN Pond 2A Yes Station Company Harding Street Generating Indianapolis Power & Light IN Pond 2B Yes Station Company Harding Street Generating Indianapolis Power & Light IN Pond 3 Yes Station Company Michigan City Generating Northern Indiana Public Service IN Michigan City Boiler Slag Pond None reported Station Company Petersburg Generating Indianapolis Power & Light IN Pond A' Yes Station Company Petersburg Generating Indianapolis Power & Light IN Pond C Yes Station Company Petersburg Generating Indianapolis Power & Light IN Pond A Yes Station Company R.M. Schahfer Generating Northern Indiana Public Service IN Waste Disposal Area Yes, alleged ASD Station Company R.M.