Objective 1: Meet TNRCC Requirements for Site Closure

Attainment of Risk Reduction Standard Number 1: Closure/Remediation to Background

Remove all hazardous and non-hazardous waste and waste residues and contaminated design and operating system components such as liners, leachate collection systems, and dikes from the unit or area of the unauthorized discharge. For remediation of media that have become contaminated by releases from a waste management unit or by other unauthorized discharge of hazardous or non-hazardous waste, the contaminated media must be removed or decontaminated to cleanup levels specified in this section (30 TAC 335.554(b) and (c)).

Surface soil sampling were collected under Building 90 and soil borings were advanced in and around Building 90. Samples were analyzed for metals, VOCs, and, in some cases, SVOCs and TPH.

No. Reported TCE concentrations exceeded RRS1 closure concentrations for soil samples collected at borings advanced near the drainage line that runs from the vats inside Building 90 to the drainage ditch. The borings for which TCE SQLs are exceeded lie within the confines of the TCE plume identified in the soil gas survey.

Further work is needed to characterize the migration characteristics of TCE around AOC65 and to characterize the extent of contamination around SB03.

Determine compliance with RRS1 closure requirements by comparing to background as represented by results of analyses of samples taken from media that are unaffected by waste management or industrial activities. If the practical quantitation limit (PQL) is greater than background, then the PQL rather than background shall be used as the cleanup level provided that the person satisfactorily demonstrates to the executive director that lower levels of quantitation of a contaminant are not possible (30 TAC 335.554(d)).

Contaminant concentrations were compared to second revised background levels (Parsons, February 2002) or RLs, which are equivalent to PQLs.

No. Not all results were below background metals levels or RLs, as described above.

Further work is recommended. See above.

Attainment of cleanup levels shall be demonstrated by collection and analysis of samples from the media of concern (30 TAC 335.554(e)).

Surface and subsurface samples were collected at the site and analyzed for contaminants of potential concern, including metals, VOCs, SVOCs, and TPH.

No. See above.

Further work is recommended. See above.

Objective 2: Meet Requirements of 3008(h) Order for RFI

RFI Workplan Requirements

Field Sampling (Detailed listing of methods and procedures are provided in project plans which are incorporated by reference).

Conduct field sampling in accordance with procedures defined in the project work plan, SAP, QAPP, and HSP.

All sampling was conducted in accordance with the procedures described in the project plans.

Yes.

NA

Facility Investigation

Characterization of Environmental Setting - Hydrogeology (B.3.A.1)

Evaluate hydrogeologic conditions at the site.

Groundwater of the Trinity Aquifer is being addressed through the Groundwater Investigation.

NA

NA

Characterization of Environmental Setting- Soils (B.3.A.2)

Characterize soils in accordance with USCS soil classification system (B.3.A.2(a)).

Soil types at the site are based on the SCS Bexar County Soil Survey (USDA, 1991) and are described in Section 1.2.1.

Yes.

NA

Determine soil pH (B.3.A.2(e)).

The pH of each of the soil types evaluated as part of the background metals concentration study was determined through laboratory analysis. According to those analyses, the pH of Crawford and Bexar Complex soils is 7.77.

Yes.

NA

Determine moisture content (B.3.A.2(g)).

The moisture content of each sample was analyzed and reported in the laboratory package.

Yes.

NA

Characterization of Environmental Setting – Surface Water and Sediment (B.3.A.3)

Characterize marshes, creeks, wetland areas, or ditches at the site.

No marshes, creeks, or wetland areas are present at the site. A ditch is located approximately 50 feetwest of AOC 65. Direction of runoff flow has been evaluated in Section 1.2.1.

Yes.

NA

Source Characterization (B.3.B)

Identify the source area (B.3.B.1).

A description of the potential source area is provided in Section 1.1.2.2.

Identify the location of the unit/disposal area (B.3.B.2(a)).

The boundaries were initially marked from review of CSSA records, and confirmed by field investigations.

Yes. Although the accuracy of the boundary survey of the site is estimated to have an approximate error of 25 feet, this accuracy is sufficient for closure under RRS1.

NA

Identify the type of unit/disposal area (B.3.B.2(b)).

A drainage line was identified that ran from Building 90 to a drainage ditch.

Further work is recommended. See above.

Identify design features (B.3.A.2(c)).

All available information regarding the design of the site is provided in Section 1.1.

NA

Identification of past and present operating practices, period of operation, age of unit/disposal area, and method used to close the unit/disposal area (B.3.B.2(d), (e), (f), and (h)).

All known information regarding these items is provided in Section 1.1.2.1. This information is from records review, interviews, aerial photo review, and visual observations.

NA

Determine general physical conditions of the site (B.3.B.2(g))

The general physical condition of the site was determined during the field investigation. This information is presented in Section 1.1.2.3.

Yes.

NA

Identify waste characteristics, including type of waste placed in the unit, physical and chemical characteristics of the wastes, and migration and dispersal characteristics of the waste (B.3.B.3).

Records regarding historic waste disposal practices at CSSA are very limited. All known information, derived from the Environmental Assessment (if appropriate for your site), records review, interviews, and visual observations at the site is provided in Section 1.3.

Yes. To the extent possible with the data available.

NA

Contamination Characterization – Groundwater (B.3.C.1)

Characterize the vertical and horizontal extent of groundwater contamination.

No.

Further work is recommended. See above.

Contamination Characterization – Soil (B.3.C.2)

Determine vertical and horizontal extent of contamination (B.3.C.2(a)).

Surface and subsurface soil samples were collected to determine horizontal extent of contamination, if any.

In most areas, TCE was detected only in soils, and not in bedrock. Around the drainage line, however, TCE was detected in the bedrock.

Further work is recommended. See above.

Describe soil properties (B.3.C.2(c)).

See “Characterization of Environmental Setting – Soils” above.

NA

NA

Identify the direction of contaminant movement (B.3.C.2(d)).

Contaminant movement appears to be in the soils, in a south-southwest direction.

NA

NA

Extrapolate future contaminant movement (B.3.C.2(e)).

Soil boring and groundwater samples were collected at AOC 65.

Samples collected at AOC 65 exceeded closure criteria for PCE, and, in some locations, other COCs.

Further work must be done to clarify the mobility of the COCs.

Implement a soil boring investigation to determine the extent of soil contamination. Soil gas monitoring will be performed during drilling of all borings. Laboratory analysis of borings for contaminants of potential concern will be performed on soils at depths where either visual contamination is evident, or soil gas concentrations indicate contamination. All boreholes shall be properly abandoned.

Soil borings were advanced in and around Building 90. Soil gases were monitored during boring collection, and laboratory analyses were performed on samples retained from portions of the borings that appeared, via PID measurements, to potentially contain COCs.

Yes.

Further work is recommended. See above.

Prepare a map of all areas included in the investigation (B.3.C.2(i)).

Figures included in this report show all areas included in the investigation.

Yes.

NA

All reporting limits should be below regulatory criteria.

RLs were approved by TNRCC on October 5, 1999. RLs are considered RRS1 standards for all analytes except metals.

Yes.

NA

Perform all analyses in accordance with the AFCEE QAPP.

All analyses were performed in accordance with the AFCEE QAPP and approved variances.

Yes.

NA

All data flagged with “U,” “F,” “M,” and “J” are considered usable for site characterization purposes.

Yes.

NA

Contaminant Characterization – Sediment and Surface Water (B.3.C.3)

Conduct a surface water and sediment investigation to characterize contamination resulting from releases at the Facility.

AOC 65 is located 50 feet east of a ditch. This ditch only contains water during and shortly after heavy precipitation. Therefore, surface water was not sampled as part of the AOC 65 investigation.

NA

NA

Potential Receptors (B.3.D).

Collect the information necessary to describe the human populations and environmental systems that are susceptible to contaminant exposure from the Facility.

Information regarding receptors is provided in the Risk Assessment Technical Approach Document (Volume 1-6). In addition, the Well Research Report identifies private groundwater users within 0.25-mile and public water suppliers within 0.5-mile of CSSA

Yes.

NA