[Work Plan Index] [Next Section]
This document presents the work plan in support of investigation and closure of the solid waste management units (SWMUs) at Camp Stanley Storage Activity (CSSA), Texas, listed under Section 1.1.2. This work plan has been developed to comply with all appropriate regulatory requirements for closure of SWMUs as stated in 40 Code of Federal Regulations (CFR), part 265 and 30 Texas Administrative Code (TAC) 335, subchapters A, E, and S. This work plan describes specific closure activities anticipated to be necessary to satisfy regulatory requirements for closure of the SWMUs identified in this plan. The CSSA US Environmental Protection Agency (EPA) identification number is TXD2210020739, and its Texas solid waste registration number is 69026.
This document was prepared by Parsons Engineering Science, Inc. (Parsons ES) of Austin, Texas, for CSSA under the U.S. Air Force Air Mobility Command (AMC) Contract F11623-94-D0024, delivery order RL17.
In addition to this work plan, documents for this investigation include a Sampling Analysis Plan (SAP). The SAP is composed of the Field Sampling Plan (FSP), which discusses field procedures, and the Quality Assurance Project Plan (QAPP), which details quality assurance and control procedures for the project.
This work plan describes the scope and procedure for investigation and closure of SWMUs and is organized into six sections. The first section includes a brief discussion of the facility history and a general description. Section 2 is an explanation of the regulatory background for closure of SWMUs, rationale, and selection of specific actions involved in the closure procedures. Section 3 describes the reporting requirements. The anticipated project schedule for RL17 is in Section 4, while amendments to work plans RL33, RL53 and 23 are found in Section 5, Section 6, and Section 7, respectively.
The objectives the RL17 project are twofold. The first objective is to assess the closure potential of each of eight low priority units, thirteen medium priority units, and seven high priority units located at CSSA with regards to closure standards of 30 TAC 335 Subchapter S. At least two of the eight presently listed low priority SWMUs, site B-14 and the coal bins, are expected to be delisted and not anticipated to require closure.
The second objective is to obtain certified closure of the SWMUs that meet Risk Reduction Standard 1 closure requirement from the Texas Natural Resources Conservation Commission (TNRCC). Based on preliminary information, the units that are expected to be closed under Risk Reduction Standard 1 include all low and medium priority SWMUs. Additionally, noninvasive investigations of SWMUs building 43, I-1, B-10, B-15/16, B-23, and B-23A are to be conducted. A treatability study may be conducted at O-1 pending the outcome of current investigations. Assuming all closure actions for low and medium sites have been completed, investigations at high priority sites will continue, based on schedule and budget constraints.
Risk Reduction Standard Number 1, the standard under which each appropriate unit will be submitted for closure, refers to hazardous constituent levels at or below background concentrations in soil and groundwater. Closure of SWMUs is accomplished by collecting and analyzing an adequate number of samples to demonstrate attainment of appropriate action levels and presenting closure documentation to the TNRCC. A detailed description of the TNRCC closure standards are presented in Section 3.2 of this work plan.
Parsons ES will complete the following tasks in order to obtain the necessary documentation for closure of the specified SWMUs:
|
Letter reports to delist two areas that were previously identified as low priority SWMUs (B-14 and coal bins). |
|
|
Limited field investigations for six low priority SWMUs (B-5, B-6, B-7, B-22, B-25 and B-26), including sampling and analysis and geophysical surveys. |
|
|
Conventional field investigations for thirteen medium priority SWMUs (B-1, B-8, B-9, B-12, B-13, B-19, B-27, B-29, B-30, B-31, B-32, B-33, and B-34), including geophysical surveys and surface and subsurface soil sampling. In addition, groundwater will be sampled and analyzed if the possibility exists that the groundwater is contaminated. |
|
|
A possible treatability study at one high priority SWMU (O-1). |
|
|
Mapping, geophysical surveys, and soil gas surveys at three high priority units (building 43, I-1, and B-10). |
|
|
Soil surveys at three high priority SWMUs (B-15/16, B-23, and B-23A). |
|
|
Should budget and schedule allow, additional closure activities may be performed at other high priority SWMUs. |
Two of the eight low priority units, site B-14 and the coal bins, are anticipated to be delisted and not require further investigation. The minimal field investigations for six of the eight low priority units to be investigated will include mapping, geophysical surveys, and a minimum of three surface soil samples. Geophysical surveys and a minimum of three soil borings may be completed at all thirteen medium priority sites. Samples will be taken from each soil boring, at the surface, middle, and total depths. Groundwater monitor wells will be located based on sampling results from soil borings. Soil borings where a saturated zone is identified will be sampled at the unsaturated-saturated zone interface in accordance with the FSP. If these sample results indicate contamination, then a groundwater monitor well will be installed at that boring and the groundwater sampled. If no contamination is indicated at the unsaturated-saturated interface, then the boring will be abandoned in accordance with the FSP. All proposed groundwater monitor wells will be approved for installation by CSSA and AFCEE personnel prior to well construction. A minimum of three groundwater monitor wells will be installed per SWMU where groundwater is encountered and monitor well installation is deemed necessary.
O-1 which was characterized during previous investigations (Parsons ES, 1995a; 1995b; and 1995c), may undergo a treatability investigation pending the outcome of a current investigation being performed under another contract discussed below. The additional high priority SWMUs listed in this work plan will undergo noninvasive investigations to help identify closure potential.
The proposed intent of the oxidation pond treatability investigation was to address remedial alternatives for the O-1 unit, and to investigate both in-situ and ex-situ options. However, some of this work that had been proposed is currently underway for an investigation into potential sources of groundwater contamination by PCE and other chlorinated volatile organics. This groundwater work was performed under U.S. Air Force Armstrong Laboratory (AL/OEB) contract F33615-89-D-4003, Order 67.