Objective 1:  Meet TNRCC Requirements for Site Closure

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

Attainment of Risk Reduction Standard 1

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)).

Geophysical surveys using the EM-31 and GPR detected anomalies potentially related to subsurface waste.  In addition, waste and fill material was encountered  during drilling of some of the soil borings.

No.

For RRS1 closure, excavate contaminated soil and remove waste and waste residue.   Collect conformation samples following excavation activities to verify that all waste residue has been removed.

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 PQLs.

Analytical results indicate that toluene, methylene chloride, dichlorodifluoromethane, and bis(2-ethylhexyl)phthalate as well as copper, nickel, zinc, barium, cadmium, mercury, and chromium are present at concentrations exceeding RRS1 criteria.

VOCs and SVOCs are likely associated with laboratory and/or field equipment contamination.  Most metals were detected below Texas-specific median background concentrations.  Only cadmium, mercury, and nickel concentrations exceeded Texas-specific background.

See above.

Attainment of Risk Reduction Standard 1 (cont.)

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

Twelve soil borings were drilled to characterize subsurface soil/rock at SWMU B-4.  Four samples were taken from each boring; one soil sample was taken from the surface, two samples were collected from near the middle of the boring, and one at total depth. The analytes for the soil samples collected at SWMU B-4 were VOCs, SVOCs, metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, and zinc) and explosives.

No.  See above.

NA

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.

Shallow groundwater was not encountered during drilling 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 Tarrant Association, Gently Undulating soils is 8.08.

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 1.2.1.

Yes.

NA

Source Characterization (B.3.B)

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

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

Yes. The contamination is most likely the result of solid waste disposal and trash burning conducted at the site. 

NA

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

The boundaries marked on aerial photo by CSSA’s environmental coordinator were digitized.

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 by visual observation of waste in the field and a records review.

Yes.  SWMU B-4 was a trench-and-fill type of disposal area.

NA

Source Characterization (B.3.B (continued)

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

Information regarding design features was obtained during the Environmental Assessment (ES, 1992) and through visual observations during the field investigation. 

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.  This information is from the Environmental Assessment, records review, interviews, 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 1.1.2.

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 records review, interviews, and visual observations at the site is provided in Section 1.1.2.2.

Partially.  Investigation results indicate that solvents/fuels were not likely disposed at SWMU B-4.  It is unknown if munitions were disposed at the site.

Excavate waste and waste residue.  Excavation activities should be overseen by UXO specialist and before waste is sent to landfill for proper disposal, UXO specialist should certify that it is free of UXO.

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 the Groundwater Investigation.

NA

NA

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

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

A total of 17 soil borings have been advanced within the SWMU and four samples were collected from each boring.  VOCs, SVOCs, and metals were detected in quantities above their respective RLs and background levels.

Yes.  The numerous borings show only limited contamination above background levels.

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)).

No actions taken.

NA

NA

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

No actions taken

NA

NA

Implement a soil boring investigation to determine the extent of soil contamination.

Seventeen soil borings were drilled and sampled at the site.  A PID was used to monitor for organic vapors during drilling.  Samples were sent to a laboratory for analysis, and boreholes were properly abandoned.

Yes.

NA

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

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

Perform all analyses in accordance with the AFCEE QAPP (cont.).

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

All “R” flagged data are considered unusable. Due to poor surrogate recovery, thirteen organic analytes were rejected in two samples.  There were also 2 metals rejected in 6 soil samples.  The rejected data were a result of non-compliant relative percent differences (RPDs) between the sample and its field duplicate.  

Yes.  Although these data were rejected, the objective of site characterization has been met.

Regarding the reject SVOC data, these rejections occurred in a duplicate sample.  None of the analytes were rejected in the parent sample.  Furthermore, the analytes that were rejected in the duplicate sample are not contaminants of concern at the site.  Therefore, these rejections do not compromise the site characterization.

Mercury results at B4-SB4 (4.5-5 ft, 8-10 ft, and 8-10 ft FD) and B4-SB13 (14.5-15 ft) were rejected, and arsenic results at B4-SB11 (15-15.5 ft) and B4-SB08 (10-10.5 ft) were rejected.  However, since such a small number of samples were rejected and since these analytes did not exceed background in the majority of the site samples, these rejections do not compromise the site characterization.

None.

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.

SWMU B-4 lies 600 feet from Salado Creek.  In the vicinity of CSSA, Salado Creek only contains water during and shortly after heavy precipitation.  Therefore, surface water was not sampled as part of the SWMU B-4 investigation.  Sampling of sediments in association with the SWMU B-4 investigation is not warranted due to the very limited amount of contamination detected at SWMU B-4.

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