Coal Ash Risk Assessments. What Do They Tell Us? Lisa JN Bradley, Ph.D., DABT

Transcription

1 Coal Ash Risk Assessments What Do They Tell Us? Lisa JN Bradley, Ph.D., DABT ewoca May 2015

2 Discussion of Coal Ash Needs Context What do we hear about coal ash? Coal ash is toxic Environmental disasters Witches brew EPA s Damage Cases after review for the final CCR Rule: 21 Proven Damage Cases (old plus new): Off site MCL exceedance (11) Proven ecological damage (10)

3 Coal Ash Toxicity and Risk Assessments EPRI, 2010 Coal Ash Material Safety ACAA, July 2012 TVA Kingston Health and Ecological Risk Assessments Dan River, NC Labadie Energy Center EPA Risk Evaluation of Encapsulated Uses for Coal Ash European REACH Assessments for Coal Ash USEPA CCR Risk Assessments: 2010 and 2014 CCR v. MSW Leachate

4 EPRI: Coal Ash Levels Similar or Less than Risk Based Screening Levels Trace Element Concentration Ranges in Fly Ash Compared to EPA Residential Soil Screening Levels As = Arsenic Ba = Barium Cd = Cadmium Cr = Chromium Pb = Lead Hg = Mercury Se = Selenium Ag = Silver Sb = Antimony Be = Beryllium B = Boron Co = Cobalt Cu = Copper Mn = Manganese Mo = Molybdenum Ni = Nickel Tl = Thallium V = Vanadium Zn = Zinc Source: EPRI, Comparison of Coal Combustion Products to Other Common Materials Chemical Characteristics. Report No Available for download at

5 ACAA Report I Coal Ash Material Safety A Health Risk-Based Evaluation of USGS Coal Ash Data from Five US Power Plants usa.org/portals/9/files/pdfs/acaa_coalashmaterialsafety_june2012.pdf

6 ACAA Report II USGS Data on Coal Ash Constituents Geochemical Database of Feed Coal and Coal Combustion Products (CCPs) from Five Power Plants in the United States. Data Series 635. US Geological Survey (USGS). Available at: Fly ash and bottom ash datasets selected to represent material put into beneficial use Data compared to USEPA Regional Screening Levels (RSLs), which are levels considered by the Agency to be protective for humans (including sensitive groups) daily exposure in a residential setting over a lifetime

7 ACAA Report III All concentrations of 15 of the 20 elements in fly ash are below residential soil screening levels, including those singled out by ENGOs in communications: Pb, Hg, Cd, and Se Only the fly ash data for the Ohio plant has an upper bound concentration of arsenic that is slightly above USEPA s risk range (2 in 10,000 vs. 1 in 10,000) Upper bound levels of As, V, Cr, Co, and Tl slightly above the RSL in fly ash Fly Ash Bottom Ash Source: ACAA. July Green = RSL; Purple = 10 th -90 th %iles in CCPs; Grey = 10 th -90 th %iles in US soil.

8 TVA Kingston Release Study I December 22, 2008 release of ~4.1 million tons of coal ash into the Emory and Clinch Rivers Human Health Evaluation Results ATSDR & TDOH Public Health Assessment The Tennessee Department of Health concludes that no harm to the community s health is expected from touching the coal ash. This includes children who might touch the ash while playing. ORAU center/newsreleases/2010/fy10 53 kingston plant medical screeningresults.aspx No adverse health effects were found among those Roane County residents who elected to participate in medical evaluations following the December 2008 fly ash spill at TVA s Kingston Fossil Plant. Medical experts at Oak Ridge Associated Universities and Vanderbilt University Medical Center released their findings.. CERCLA Risk Assessment No adverse risks to human health

9 TVA Kingston Release Study II Ecological Few adverse ecological effects have been identified in the several years of study postrelease Laboratory sediment toxicity at only >40% ash No long term benthic community, fish community, or fish health impacts No observable impacts on reproductive competence of fish, birds, or turtles Near field bioaccumulation of As and Se peaked early, but did not reach adverse effect levels No significant sub lethal effects

10 TVA Kingston Release Study III Integrated Environmental Assessment and Management Volume 11 Issue 1 January Coal ash ecological risk assessment in context: Lessons learned from the Kingston Fossil Plant ash spill How toxic is coal ash? A laboratory toxicity case study Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee: Site setting and problem formulation Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee: Limited alteration of riverine reservoir benthic invertebrate community following dredging of ash contaminated sediment Effects of coal fly ash on tree swallow reproduction in Watts Bar Reservoir, Tennessee Evaluating risks to wildlife from coal fly ash incorporating recent advances in metals and metalloids risk assessment Application of ecological risk assessment in managing residual fly ash in TVA's Watts Bar Reservoir, Tennessee Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee

11 Dan River, NC I February 2, 2014 Dan River release of 38,000 tons of coal ash due to a failed pipe below the ash pond NC State (April 2014) Report on trace element impacts on agricultural use of water from the Dan River post release state study shows dan river water safe for irrigation livestock/ Assuming that water quality trends along the Dan River can be projected from hundreds of water analyses made during a 40 day period following the February 2014 spill, NC State concluded that: 11 Total concentrations of trace elements ( total metals ) in Dan River water declined sharply from maximum levels that were typically measured one day after the ash release. Concentrations measured 2.2 miles downriver of the spill site were equivalent to upstream concentrations within 3 days after the coal ash release. River water is suitable for use as irrigation water on crops and as drinking water for livestock. Trace element influx during flooding of agricultural areas will have only a marginal impact on soils and crops.

12 Dan River, NC II NC DHHS (July 2014) DHHS is recommending lifting the recreational water advisory after evaluating the most recent available surface water and sediment data from the Dan River downstream from the coal ash spill. DHHS has evaluated sediment and surface water data collected after the work was completed that confirms that no incidental ingestion or skin contact risk exists for the sediment or the river water. Contaminants associated with the coal ash spill are at levels that should not pose a health risk during recreational use of the river. A potential fish and shellfish consumption hazard still exists immediately downstream of the release. DHHS recommends that people not consume any fish or shellfish collected from the Dan River in North Carolina downstream of the Duke Power Eden spill site _revised_dan_river.htm 12 EPA Fact Sheet on Kerr Reservoir (May 2014) Located 80 miles downstream There have been no exceedances in human health screening in the surface water samples collected from Kerr Reservoir for contaminants of concern from the coal ash. bbf ac 8ba2 524ec8bca013&groupId=14 NC DENR (Nov 2014) Aquatic insect communities in an area downstream from the Feb. 2 coal ash spill appear to be thriving, according to the results of testing conducted by state environmental officials. In October 2014 DENR sampled upriver and ~2 miles downriver of the spill for aquatic insects, worms and other invertebrates at the base of the food chain. Their numbers, type and diversity signal a river's overall health. Findings were similar upstream/downstream and had the highest biological rating. Agency says bugs "appear to be thriving" at the bottom of the Dan River. Id= &articleId=

13 Labadie Energy Center 13

14 USEPA Study Reaffirms Concrete and Wallboard Uses USEPA on February 7, 2014, released an exhaustive study re affirming the Agency s support for two major uses of coal ash fly ash in concrete and FGD gypsum in wallboard: environmental releases of constituents of potential concern (COPCs) from CCR fly ash concrete and FGD gypsum wallboard during use by the consumer are comparable to or lower than those from analogous non CCR products, or are at or below relevant regulatory and health based benchmarks for human and ecological receptors EPA supports the beneficial use of coal fly ash in concrete and FGD gypsum in wallboard. The Agency believes that these beneficial uses provide significant opportunities to advance Sustainable Materials Management (SMM).

15 15 REACH CCP Human Health Toxicity Data for "Ashes, Residues" Endpoint REACH CCP Human Health Toxicity Data Publications and Reports Conclusion Acute Oral Toxicity 3 No Hazard Acute Inhalation Toxicity 1 No Hazard Acute Dermal Toxicity 2 No Hazard Skin Irritation 8 No Hazard (7) Inconclusive (1) Eye Irritation 4 No Hazard (3) Inconclusive (1) Skin Sensitization 2 No Hazard Repeated Dose Inhalation Toxicity 3 No Hazard Repeated Dose Oral Toxicity 2 No Hazard Genetic Toxicity 5 No Hazard Reproductive Toxicity 2 No Hazard Carcinogenicity NA No Hazard Total 32 Source: EC#

16 EPA s CCR Risk Results 2010 Context is Important EPA risk results: 2:100 (1:50) to 2:1,000 for unlined impoundments 4 5:10,000 for unlined landfills Lined landfills below levels of concern EPRI evaluated aerial photos for 508 facilities noted locations of apparent downgradient dwellings in areas not serviced by municipal water: < 3,000 Assume all locations have unlined surface impoundments: <3,000 dwellings = 7,770 people = <155 cancer cases v. 3,237 bkg cancer cases <155 cancer cases in US population of 307,006,550 or 2 in 10 million Landfills: 4 cancer cases out of the downgradient population of 7,770 and out of the US population of 307,006,550

17 EPA s CCR Risk Results 2014 Context is Still Important EPA risk results: 2:10,000 for impoundments (100x lower than 2010) 5:1,000,000 for landfills (100x lower than 2010) No 90th percentile risks above ecological criteria were identified for either surface impoundment or landfills. No 50th percentile risks above human health or ecological criteria were identified for either surface impoundment or landfills. EPRI evaluated aerial photos for 508 facilities noted locations of apparent downgradient dwellings in areas not serviced by municipal water: < 3,000 For surface impoundments: <3,000 dwellings = 7,770 people = <1.5 cancer cases v. 3,237 bkg cancer cases <1.5 cancer cases in US population of 307,006,550 or in 10 million Landfills: <1 cancer case out of the downgradient population of 7,770 and out of the US population of 307,006,550

18 Risk Based Comparison of MSW and CCP Leachates Leachate Ratio MSW/CCP (**MSW Risks Higher) Summary of Results Human Health Cancer 90 th Percentile Results 40 CFR Characteristic Hazardous Waste Human Health Non Cancer ECO 1.2** 1.1** 191** CCR? Ignitability No Corrosivity No Reactivity No Toxicity Characteristic No MSW and CCP Physical Comparisons MSW Landfill CCP Management Unit Similar leachate toxicity? Biologically active? Emits explosive gases? Emits greenhouse gases? Often contains sewage sludge? Attracts disease vectors? (rodents, insects, scavengers) Conclusion Coal ash can be safely managed under a Subtitle D landfill design regulation Source A Risk-Based Comparison between Coal Combustion Product Landfills and Impoundments and Municipal Solid Waste Landfills EPRI Research Report No Available for download at

19 Risk evaluations for coal ash constituents, and testing of coal ash itself indicate that there is little or no risk posed by direct contact. While the Kingston and Dan River impoundment releases were initially catastrophic, the risk posed to human health after the releases was low, and the ecological systems have rebounded quickly. These releases were of coal ash and associated liquids. Studies of groundwater discharge from impoundments and landfills do not always show impact on surface water systems. Lisa JN Bradley, Ph.D., DABT