Objective 1: Meet TNRCC Requirements for Site Closure

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

Remove all hazardous and nonhazardous 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 nonhazardous waste, the contaminated media must be removed or decontaminated to cleanup levels specified in this section (30 TAC 335.554(b) and (c)).

Characterization of contamination was conducted during this investigation. No waste or waste residue was removed.

No

Additional sampling is recommended to define lateral extent of contamination.

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 PQL is greater than background, then the PQL rather than background shall be used as the cleanup level, provided 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 revised background levels (Parsons, February 2002) or PQLs (AFCEE RLs).

No. Several results exceeded background.

Additional sampling and remediation is recommended.

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

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

No. Contamination above background was detected.

Additional sampling and remediation is recommended.

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

B.2. Task II: RFI Workplan Requirements

Field Sampling.

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

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

Evaluate hydrogeologic conditions at the site.

Install monitoring wells if shallow groundwater is encountered at the site. Shallow groundwater was not encountered during sampling 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 (NRCS, 1991) and are described in Section 1.2.1 of the SWMU B-34 RFI Report (Parsons, 2002). Crawford and Bexar is the single soil type present at SWMU B-34.

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 soils is 7.89.

Yes

NA

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

The moisture content of each sample was determined during laboratory analysis.

Yes

NA

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

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

A ditch is present just south of the site area near the piping outfall area. Surface soil samples were collected from the ditch.

Yes

NA

Source Characterization (B.3.B)

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

A description of the source area is provided in Sections 1.1.2.2 of the SWMU B-34 RFI Report (Parsons, 2002).

Yes. The source of possible contamination is considered to be the maintenance pit.

NA

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

In 1999, points along the boundary of each site were surveyed with a Rockwell Plugger GPS unit (estimated accuracy of ±25 feet). The measurement points were identified by the CSSA Environmental Coordinator. The boundary of the site was reviewed during preparation of this report and adjusted, if necessary, based on observations made during the field investigation.

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. If CSSA opts to close the site under RRS2, a metes and bounds survey by a licensed surveyor will be necessary.

NA

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

The type of unit/disposal area was identified in the Environmental Assessment.

Yes.

NA

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

Information regarding design features was obtained during the Environmental Assessment (ES, 1992) and through visual observation during the field investigation. All available information regarding the design of the disposal site is provided in Section 1.1.2.1 of the SWMU B-34 RFI Report (Parsons, 2002).

Yes

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 of the SWMU B-34 RFI Report (Parsons, 2002). This information is from the Environmental Assessment, records review, interviews, aerial photo review, and visual observations.

To the extent possible with data available.

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 2.1 of the SWMU B-34 RFI Report (Parsons, 2002).

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, records review, interviews, and visual observations at the site is provided in Section 1.1.2.1 of the SWMU B-34 RFI Report (Parsons, 2002).

Yes

NA

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

Characterize the vertical and horizontal extent of groundwater contamination.

Shallow groundwater was not encountered during sampling at the site.

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

NA

NA

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

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

Collected fourteen surface soil samples at the site to determine the extent of contamination. Descriptions of the sampling activities and other field activities are provided in Section 2.

No. Horizontal extent of surface soil contamination has not been determined.

Additional soil sampling is recommended to determine the horizontal extent of surface soil contamination.

Describe contaminant and soil properties with the contaminant source area, including contaminant solubility, speciation, adsorption, leachability, exchange capacity, biodegradability, hydrolysis, photolysis, oxidation, and other factors that might affect contaminant migration and transformation (B.3.C.2(b)).

See “Characterization of Environmental Setting – Soils” above and Section 1.2 of the SWMU B-34 RFI Report (Parsons, 2002).

Yes

NA

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

See “Characterization of Environmental Setting – Soils” above.

Yes

NA

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

NA

NA

NA

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

No action taken.

NA

NA

Implement a surface soil sampling investigation to determine the extent of soil contamination. Laboratory analysis for contaminants of potential concern will be performed on soils.

Collected fourteen surface soil samples at the site.

Yes

Further surface soil sampling.

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

Provided appropriate figures of the site. Figures of the site and locations of surface soil samples are provided in Figure B34-8.

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. “M” flagged data are considered usable because the matrix interference is minimal and does not significantly affect the sample results.

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