Mike Knoedl Ricky Chastain Keeping the Natural State aatural. DPputy D~rector Deputy D~rector Arkansas Game and Fish Commission Mike Armstrong Deputy D~rector Jeff Crow October 22, 2013 Ryan Benefield, Deputy Director Arkansas Dept. ofEnvironmental Quality 5301 Northshore Drive North Little Rock, AR 72118-5317 Little Rock, AR 72201 Re: ExxonMobil Pipeline Company's Pegasus Pipeline Oil Spill at Mayflower, AR March 29, 2013- AGFC Comments on the ExxonMobil Environmental Services Company Downstream Areas Data Assessment Report Dear Mr. Benefield: In follow-up to recent communications between our respective agencies' staff members, I am providing the following comments from Arkansas Game and Fish Commission, prepared with assistance of our consultant, Industrial Economics, Inc., regarding ExxonMobil Environmental Services Company's Downstream Areas Data Assessment Report. A preliminary review was conducted of the above-named report. The report is very comprehensive and provides detailed data collected during the fieldwork and conducted by the analytical laboratories. The data quality is high. However, we note that there are three areas where the report needs revision: 1. The evaluation of the polynuclear aromatic hydrocarbons (P AHs) in soils and sediments is not acceptable in that it analyzes only a subset ofPAHs, thereby possibly substantially understating the potential for impacts asserted in ExxonMobil's report. In the analysis ofthe PAH chemical results, we disagree with ExxonMobil's statement on page 5-4, which states: While environmental assessments often initially focus on the 16 priority pollutant PAils designated by USEP A, AGFC requested that a longer list of 43 non-alkylated and alkylated PAils be evaluated during the development of the DARSP; therefore, separate summations using a longer list ofPAH analytes are also included. Greater weight is placed on the sediment screen using the priority pollutant PAils in the summations because the sums are compared to ESVs that are based on a subset of the priority pollutants or on a single P AH. In fact, oil spill assessments should always include chemical analysis and evaluation of the alky1ated PAHs because they are present in oils at much higher concentrations than the parent PAHs in the EPA Priority Pollutant PAHs (which were developed primarily for waste sites, not oil spill sites). The "long list" of38 PAHs that they chose to use for their ecological screening 2 Natural Resources Drive • L1ttle Rock, AR 72205 • www.agfc.com Phone (800) 364-4263 • (501) 223-6300 • Fax (501) 223-6448 The Arkamas Game and F1sh Commission~ miss1on 1s to conserve and enhance Arkansas's f1sh and wildlife and their hab1tats wh1le promot1ng sustainable use, pubhc understandmg and support Ryan Benefield, Deputy Director Arkansas Dept. of Environmental Quality October 22, 2013 Page 2 of3 values (ESVs) includes only about halfofthe PAHs in the source oil. The oil spill assessment literature is clear on this -- all PAHs have the same mechanism of toxicity and should be included in risk assessments. Therefore, we have calculated toxic units (TU s) for all the sediment samples for which total organic carbon (TOC) was measured (only the surface sediment samples). In our analysis, the following surface sediments in Dawson Cove have TU values greater than1, indicating that they pose some risks to benthic organisms: SED-DA-015, TU = 1.58; SED-DA-039, TU = 1.68; SED-DA-045, TU = 2.2; and SED-DA-046, TU = 1.01. In contrast, the ExxonMobil TU calculations are such that all sediment and soil samples have a TU less than 1. Therefore, we disagree with the statement on page 7-6 where they state: Therefore, no further evaluation ofP AHs in Dawson Cove sediment is necessary. Also, the 0.5- 1.0 foot samples at SED-DA-017, with a total PAH concentration of26,580 fJg/kg, might also have a TU > 1; however, TOC was not measured so the TU cannot be accurately calculated. Assuming that the TOC is the same as the surface sample, it would have a TU = 1.93. Therefore, we request that ExxonMobil re-analyze the data on PAHs in soils and sediments using the full list ofPAHs in the source oil and revise their report and recommendations accordingly. 2. There is no fingerprinting assessment ofthe sources ofthe PAHs in the samples; that is, ExxonMobil makes no effort to document that the PAHs are from the spilled oil, even if the concentrations are below those thought to have ecological effects. We request that ExxonMobil conduct fingerprinting analyses to determine which soil and sediment samples are contaminated with the source oil. 3. The Sediment Profiling Imagery (SPI) method was not used for the Lake Conway Depositional Assessment. The Downstream Areas Remedial Sampling Plan says (p. 15) that: The SPI can be used to measure and qualitatively evaluate a variety of physical, chemical, and biological parameters including: grain size, surface boundary roughness, Depth of apparent redox potential discontinuity, rrosional or depositional features, subsurface methane gas pockets, and observation of benthic organisms. The images will provide additional information to assist in evaluating both the presence and extent of recent sediment deposition that may be associated with spill response activities. The cores taken, instead, are of poor visual quality and it is difficult to compare the differences in the sediment layers between the sites near Dawson Cove and upstream areas. Further, no information was obtained regarding many of the parameters listed above, and in particular, bioturbation degree and depth. Therefore, it is recommended that ExxonMobil repeat the Sediment Deposition Evaluation using the SPI method. 2 Natural Resources Drive • Little Rock, AR 72205 • www.agfc.com Phone (800) 364-4263 • (501) 223-6300 • Fax (501) 223-6448 The Arkamas Game and F1sh Comm1ss1on's mission 1s to conserve and enhance Arkansas's fish and wildlife and their hab1tats while promot1ng sustainable use, public understandmg and support Ryan Benefield, Deputy Director Arkansas Dept. of Environmental Quality October 22, 2013 Page 3 of3 We appreciate collaborating with ADEQ and its staff on this important matter. Please do not hesitate to contact me at (501) 223-6306 should you have questions or concerns regarding any of AGFC's comments. Sincerely, ~- cc: Teresa Marks, ADEQ Director Harrelson, Tammera, ADEQ Chief Attorney Lorielle Gutting, ADEQ Attorney Tammie Hynum, ADEQ Hazardous Waste Div. Mgr. Kendra Akin Jones, Assistant Attorney General Mike Knoedl, AGFC Director Mike Armstrong, AGFC Dep. Director Jeff Crow, AGFC Dep. Director Jim Goodhart, AGFC General Counsel John Marks, AGFC Sr. Attorney Mark Oliver, AGFC Fisheries Chief Brad Carner, AGFC Wildlife Mgmt. Chief Tom Bly, AGFC District 10 Fisheries Supervisor 2 Natural Resources Drive • L1ttle Rock. AR 72205 • wvvw.agfc.com Phone (800) 364-4263 • (501) 223-6300 • Fax (501} 223-6448 The Arkansas Game and F1sh CommiSSion'!. m1ssion IS to conserve and enhance Arkansas's f1sh and wildlife and their hab1tats whde promotmg susta1nable use. pubhc understandmg and supporr