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)).

In February 1995, on EM survey and a GPR survey were conducted at the site and identified two potential disposal areas.  In June 1997, UXO removal activities were completed.  Nine UXO items were recovered, categorized and destroyed.  Scrap metal weighing 86,700 pounds were removed from the site and recycled.  Approximately 730 cubic yards of sifted soils are stockpiled at the site.

No.  Soil sample results from the stockpiled soils indicate the material is contaminated with barium, copper, mercury, and zinc above background levels.

Remediation or disposal of contaminated soil using method identified during the upcoming Soil Pile Disposition Assessment Study is recommended.  Prior to completing this remediation, verification samples should be collected in the trench areas.

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 quantification 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 quantification of a contaminant are not possible (30 TAC 335.554 (d)).

Contaminant concentrations were compared to draft revised background levels (Parsons ES, May 2001) or PQLs.

No. Results of the soil samples from the stockpiled soils indicate barium, cadmium, chromium, copper, mercury and zinc were detected above the background levels for Krum soils.

The soils at SWMU B-28 will be included in treatability study activities.  Additionally, soils samples should be collected from the excavation area to assess if excavation activities have removed all impacted soil.

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

Soil samples were collected from the stockpiles of sifted soils generated during the UXO removal activities.  Contaminants of concern for these samples were metals, VOCs, SVOCs, and explosives.

No.  Contamination above background was detected.

Additional soil sampling and remediation is recommended.

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

RFI Workplan Requirement

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

Conduct field sampling in accordance with the 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.

Shallow groundwater was not encountered during drilling at the site.

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

NA

NA

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

Characterization soils in accordance with USCA 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

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

The pH of each of he soil types evaluated as part of the background metals concentration study was determined through laboratory analysis.  According to those analyses, the pH of Krum complex soils is 7.87.

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.

No marshes, creeks, wetland areas, or ditches are present at the site.  Direction of runoff flow has been evaluated in Section 1.2.3.

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 and 1.2.

Partially.  Excavation of waste trenches confirmed the nature and location of potential source areas at the site.

Additional sampling is recommended to verify that all contaminated soil has been excavated.

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

The boundary of SWMU B-28 was visually identified in 1992.  In 1997 during excavation activities, the locations of the trenches were surveyed.

Yes

NA

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

The site was identified in the Environmental Assessment and a geophysical survey was conducted in 1995.  Two disposal trenches were identified and all waste in them was excavated and sifted to removed UXO and metal scrap.

Yes.

NA

Identify design features (B3.A.2(c)).

Information regarding design features was obtained during the Environmental Assessment (ES, 1993) and through visual observation during the field investigation.  Al available information regarding the design of the disposal site is provided in Sections 1.1 and 1.2.

Yes.  The results of the trench excavations showed that unlined pits were used for waste disposal.

NA

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

All known information regarding these items is provided in Section 1.1 and 1.2.  This information is from the Environmental Assessment, record review, interviews, aerial photo review, and visual observations.

To the extent possible with data available.

NA

Determined 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.

Yes

NA

Identify waste characteristics, including type of waste placed in the unit, physical and chemical characteristics of the wastes, and migration and disposal 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 Assessments, records review, interviews, and visual observations at the site is provided in Section 1.  In addition, waste at the site was identified through excavation.

Yes

NA

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

Characterize the vertical and horizontal extent of groundwater contamination.

Shallow groundwater was not encountered during drilling at the site.  Groundwater of the Trinity Aquifer is being addressed through Groundwater Investigation.

NA

NA

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

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

Six soil borings were completed in 1995 to assess the presence of contamination. Description of the soil boring activities and other field activities are provided in Section 2.

Soil contamination was found at shallow depths. Additional sampling is necessary to verify that all contaminated soils have been excavated.

Perform additional soil sampling to verify that the extent of contamination in the shallow site soils has been delineated.

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)).

These factors are addressed in the Soil Pile Disposition Assessment Report.

No

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)).

Contaminants were determined to be at shallow depths, and no shallow groundwater was encountered at the site.  Therefore, the contaminants appear static ad no action is needed to define the direction of contaminant movement.

NA

NA

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

NA

NA

NA

Implement a soil boring investigation to determine the extend 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.

Advanced six soil borings at the site.  Properly abandon all sol borings.  Soil boring activities are outlined in Section 2.1.

No soil gas sampling was conducted.

Yes

NA

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

Figures of the site and location of soil borings are provided in Figures B28-1 through B28-4.

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 also considered usable.  The matrix interference is minimal and does not significantly affect the sample results.

NA

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

NA

NA

NA

Potential Receptors (B.3.D)

Identify potential receptors.

Records regarding potential receptors 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 1.2.

Yes

NA