ILLINOIS ENVIRONMENTAL PROTECTION AGENCY 1021 Noam-t GRAND AVENUE EAST, PD. BOX19276, SPRINGFIELO, 62794-9276 0 (217) 782-3397 BRUCE RAUNER, GOVERNOR ALEC MessmA, DIRECTOR (217) 524-3300 October 22, 2018 HRE Crawford, LLC Attn: Mr. Ryan Lawlor 5 Revere Drive, Suite 320 Illinois 60062 Re: 0316005761/Cook County Chicago/ComEd-Crawford Station Site Remediation Program/Technical Reports Dear Mr. Lawlor: The Illinois Environmental Protection Agency (Illinois EPA) has reviewed the July 2018 Comprehensive Site Investigation Report (CSIR) document (received August 14, 201 S/Illinois EPA Log NO. 18?67656). The document was prepared by V3 Companies (V3). The CSIR document is disapproved. The following cements were generated as a result of this review: 1. 35 Illinois Administrative Code (35 IAC) requires the comprehensive site investigation to determine the nature, concentration, direction and rate of movement and extent of the 35 IAC 740 Appendix A Target Compound List (TCL) contaminants of concern (C005) and the signi?cant features of the remediation site and vicinity that may affect contaminant fate and transport and risk to human health, safety, and the environment. This regulation has not been satis?ed based on the following: a. A detailed discussion of the extent of horizontal and vertical contamination, in relation to each speci?c sample location/sample area, has not been provided. b. The frequency of analysis of the TCL in soil is de?cient for an approximately 70-acre site. The Tables in the CSIR appear to show that approximately ?ve (5) samples NS-GP-114 (7?9 feet), NS-GP-112 (7?9 feet), (1-3 feet), and NS- GOP-IOS (8-10 feet), 17 (2-4 feet)] were analyzed for the full TCL dun'ng .5192 N. Main Roc'?crd: IE. 05?: 1-93 9-51 Harrison 31., De: Plains, :l GOOH- {84329-1-452'6-3 595 3, Stan, Eight, 6012515472508?5131 412 SW Washington 82., SEEM DI, 61602 61-2-3922 3125 Era: cqampuiggl 1; 33g. {21 732:3.5 393 2:39" W. Main 82ft: 1 to, Marion, :1 6295? (61339934286 aces Mail carom-13, n. 5222.: {618334661 so too w. Rudd?s-h, Suite a-eao, Chicago, see-at the 2018 sampling event. Generally, sites in the site remediation program perform baseline TCL sampling at a frequency of two (2) TCL samples per l/5-acre. In some cases, the TCL frequency may be reduced based on the proposed site remedy pathway exclusion). However, since the proposed remedy is not known to date, additional TCL sampling is required. The ?'equency of analysis of the TCL in groundwater is de?cient for an approximately 70?acre site. The Tables in the CSIR show that only groundwater collected from four (4) groundwater monitoring wells installed by V3 in 2018 (along with four (4) wells installed by ENSR in 1998) were analyzed for the ?ll] TCL. Additional groundwater monitoring wells should be installed, and groundwater collected from these wells should be analyzed for the full TCL. In addition, some of these wells should be installed adjacent to the Chicago Sanitary Ship Canal for potential evaluation of surface water conditions (35 IAC . The frequency of analysis of TCLP metals in soil is de?cient for an approximately 70-acre site. The Tables in the CSIR appear to show that four (4) samples were analyzed for TCLP metals. Additional TCLP metals analysis should be performed where elevated total metals concentrations were observed in the March 2018 sampling event and where total metals concentrations are observed in ?lture sampling events. This TCLP analysis is pertinent to demonstrate compliance with 35 IAC 742.305 The Tables in the CSIR show that soil sampling was de?cient in speci?c areas of concern (AOCs) at the site as follows: Only one (1) soil sample was collected in the locomotive house Only two (2) soil samples were analyzed for volatile organic compounds (VOCs) in the oil/fuel/hazardous storage area Only three (3) soil samples were actually collected within the ?lled-in West Branch of South Fork of Chicago River Only one (1) soil sample was collected in the waste water treatment plant Only one (1) soil sample was collected in the ash dewatering area Only two (2) soil samples were collected in the chemical ?ll station Only one (1) sample was collected in the debris pile area (south) Only six (6) samples were collected in the generating plant Only one (1) sediment sample was collected in the oil/water separator pond Only three (3) soil samples were collected in the tractor shed/maintenance Only biphenyl (PCB) and total petroleum hydrocarbon (TPH) analyses were performed on soil samples collected in the transmission building/reactor Only one (1) soil sample was collected in the debris pile (east) VV Additional soil sampling must be performed to further characterize each speci?c REC. f. During future soil sampling activities, it is recommended that several of the soil samples analyzed should be ?om the sur?cial interval (0-3 feet). The rationale of the surface interval analysis is to evaluate potential outfall emissions from the former generating plant. 2. Multiple sections in the CSIR discuss PCB impacts above applicable remediation objectives (ROS). Ultimately, acceptance of any PCB mitigation efforts is at the discretion of the USEPA. The Illinois EPA anticipates receipt of a copy of UESPA review comments on this issue in a forthcoming document. 3. Multiple sections in the CSIR state that 21 surface and sediment samples collected in 1998 contained TPH concentrations above the 35 IAC 742.305(a) soil attenuation capacity, and all of these samples contained total TPH concentrations greater than 25,000 mg/kg. The CSIR further states that these ?ndings were not duplicated in the 2018 round of sampling and that TPH concentrations likely have naturally attenuated and are no longer present. The Illinois EPA does not concur with this conclusion. Evidence has not been provided that each speci?c 1998 sample location has been reanalyzed at the speci?c location and corresponding depth interval where the 1998 TPH results were documented. The Illinois EPA recommends each speci?c 1998 TPH concentration above the soil attenuation capacity be reevaluated appropriately. In addition, this issue is pertinent in relation to the proposed site-Speci?c fraction of organic carbon (foe) values discussed below. Finally, the soil boring logs in the document show that select soil samples collected in 2018 contained evidence of staining and/or odors and were not analyzed for TPH (4.5 feet), 11 (5-15 feet), (7-9 feet), etc.). All 2018 soil samples, as well as future soil samples collected, where staining and/or odors are documented must be analyzed for TPH at the corresponding depth intervals to demonstrate compliance with 35 IAC 742.3 05(a). 4. Multiple sections in the document state there is no evidence that mercury exists in its elemental form at the site. Based on the historical use of the site as a generating plant, the Illinois EPA does not concur that this conclusion can be certi?ed. As a result, it is recommended that all total mercury concentrations above applicable ROs be evaluated appropriately. 5. Table 4.4 in the CSIR presents the site-speci?c fog evaluation conducted at the site. The Illinois EPA does not approve of the proposed site?speci?c foe values and offers the following discussion on determining site-speci?c foe values; a. It must be demonstrated that the location of the foe samples collected correlate to the same depth and geologic unit as the contamination that is being evaluated. Speci?cally, site-speci?c physical soil parameters must be determined from the portion of the boring representing the stratigraphic unit(s) being evaluated. b. It must be demonstrated that the foe sample is collected from uncontaminated areas of the site. The Illinois EPA requires co-sampling of the fog sample for VOCs, and semi- 10. 11. 12. 13. 14. 15. volatile organic compounds (SVOCs) listed in 35 IAC 740 Appendix A.Tables A and B. The Illinois EPA anticipates receipt of reevaluation of the site-speci?c for: values in a forthcoming document. The CSIR did not discuss whether the buildings contained basements or were slab?on- grade construction or whether or not the buildings contained sumps or elevators. This is pertinent in relation to the indoor inhalation exposure route. A copy of the most recent Phase I conducted by V3 was missing from Appendix A.8. Depth of groundwater, hydraulic gradient, and groundwater ?ow direction were not discussed in detail in the CSIR. Based on North Section Tables 4.1.2 and 4.1.5, benzo(a)pyrene, and lead also exceed the soil component of groundwater ingestion exposure route R0 but were not listed in Section 5.5.1. Please clarify. Section 5.5.2 states that arsenic exceeded the construction worker ingestion R0 however South Section Table 4.2.5 did not show any exceedances for arsenic exceeding the construction worker ingestion R0. Please clarify. Based on South Section Tables 4.2.2, benzo(a)pyrene, and also exceed the soil component of groundwater ingestion exposure route R0 but were not listed in Section 5.5.2. Please clarify. Section 5.5.3 - Soil Component of the Groundwater Ingestion Exposure Route - did not discuss the soil component but discussed the monitoring wells that were installed. This section should be revised to discuss the soil component of the groundwater ingestion exposure route and the groundwater ingestion exposure route should be discussed in a separate section. Tables indicates that groundwater samples from the monitoring wells were marked as sediment samples. Please modify accordingly. TCLP lead greater than RCRA limit of 5 mg/L identi?ed at NS-GP-102 (15-17) in the West Branch of South Fork of the Chicago River should be further evaluated to determine the extent. The CSIR discusses the outfall for treated storrnwater into the Chicago Sanitary Ship Canal located in the southwest corner of the South Section. Is this outfall cover by any NPDES permit and have the outfall discharges ever been sampled? NOTE: 1. Based on the heterogeneous nature of the polynuclear aromatic hydrocarbons and metals concentrations above applicable ROS, it is recommended that the forthcoming Remedial Action Plan be tailored in a way to appropriately evaluate these contaminants of concern appropriately. 2. Please submit a Work Plan which includes the additional sampling outlined in Comments and #14 above. All future submittals to the Illinois EPA should include one (1) original and one (1) copy of each document. The Illinois EPA requests a fourteen (14) day, at a minimum, advance notice of any remedial activities at the Remedial Site so Illinois EPA personnel can schedule site visits during those activities. If you have any questions, please feel free to contact me at (217) 557-1409 or e-mail me at SincerelyTodd Hall, Project Manager Voluntary Site Remediation Unit Remedial Project Management Section Division of Remediation Management Bureauof Land cc: Mr. Ryan Hartley V3 (rhartlev@.v3eo.coml Mr. Steve G-oblernan Andrews Engineering (scobelmanmlandrews-ena.com) Mr. Chris Pressnall Environmental Justice Of?cer Bureau of Land File 10/29/2018 L016499 0316005761 31A 3,006,343 170000041238 08/14/2018 CRAWFORD ELECTRIC GENERATING STATION mammalian minimal) :01? wand-mu man ?mm - lulu-1mm mu - RECEIVE: I?ll-mm .L n2] FWW Emmy. SITE WIDE - son. BORING, MONITORING WELL AND SAMPLE