R. Steve and S. Fuller
Bechtel Svannah River Inc.

M. Mascoe
USDOE

Beginning in 1953, seven coal-fired power plants produced steam and electricity for the Savannah River Site’s (SRS) mission of producing radionuclides for national defense. SRS railroads delivered stoking coal to the power plants where the coal was stored in unsheltered stockpiles adjacent to each facility. Stormwater runoff from stockpiled coal is typically acidic, contaminant- and suspended solids-laden. When the effects of discharging coal pile runoff to the environment were recognized, SRS built unlined earthen coal pile runoff basins (CPRBs) in the late 1970’s and early 1980’s by excavating and/or berming areas downgradient from each of the coal piles. Berms, ditches, culverts, and buried pipelines collected and conveyed the stormwater runoff from the coal piles to the basins. The four CPRBs located in C-, F-, K- and P-Areas underwent closure activities during the summer of 1997.

Two of the CPRBs were previously characterized and evaluated using standard RFI/RI/BRA protocols; these studies document the similarity of conditions at these basins. Given the similarity in construction, source materials, and operating histories, only a focused assessment of the remaining two inactive basins was necessary. This resulted in a substantial reduction in time necessary to effect remediation of the four basins and allowed available budget to be redirected to the remediation of higher risk waste sites.

Upon review of analytical data, the Environmental Restoration Reactors Project Team determined the best approach for cleaning up the inactive basins would be to execute an Early Removal Action. The action consisted of removing the source material (i.e. coal and coal laden sediments) from the facilities for beneficial reuse, securing conveyance structures, backfilling the basins, restoring to natural grade, and establishing vegetation to prevent erosion on the restored surfaces.

The accelerated cleanup of the CPRBs will save $11 million over the next five years and reduce scheduled cleanup time by 92 months. This removal action also marks the first time SRS has released material from a CERCLA waste unit for beneficial reuse by the public. Approximately 13,100 tons of coal and coal laden sediments will be thermally treated and reused for roadbase under public highways. The cost for recycling is approximately one-third the cost of landfill disposal.

The Savannah River Site (SRS) occupies approximately 310 square miles of land adjacent to the Savannah River, principally in Aiken and Barnwell counties of South Carolina. It is located approximately 25 miles southeast of Augusta, Georgia, and 20 miles south of Aiken, South Carolina. Figure 1, SRS Location Map, depicts the geographical location of SRS in relation to surrounding states as well as the location of C, F, K and P Areas relative to other major SRS facilities.

The SRS, which is owned by the U.S. Government, was set aside in 1950 as a controlled area for the production of nuclear materials for national defense. The mission has been expanded to include providing nuclear materials for the space program and radioisotopes for medical purposes. SRS is a secured U.S. Government facility with no permanent residents. The U.S. Department of Energy (DOE) and its contractors are responsible for the operation of the SRS. The U.S. Environmental Protection Agency - Region IV and the South Carolina Department of Environmental Control provide regulatory oversite for waste site characterization and remediation activities at the SRS.

Originally nine coal-fired power plants, located in the A, C, D, F, H, K, L, P, and R Areas, produced steam and/or electricity for Savannah River Site (SRS) activities. Stoking coal was stored in unsheltered stockpiles at each of the power plant locations. Operations ceased at the L- and R-Area power plants in 1968 and 1964, respectively, and the stockpiled coal was removed; CPRBs were not built at these areas. Only seven of the power plants (A, C, D, F, H, K, and P) were still in use when CPRBs were constructed in 1978 and 1981. These basins were designed to protect surface water from coal pile contaminants such as suspended solids, sulfides (which weather to produce sulfuric acid), metals, radionuclides, and semi-volatile organic compounds. All of these constituents occur naturally in coal. The C, F, K and P-Area CPRBs have been inactive for several years. Table 1, Summary of Historical and Site Specific Data for the C, F, K and P-Area CPRBs, summarizes the historical information and site-specific data for the C-, F-, K-, and P-Area CPRBs. Figure 2, Location of the C-, F-, K-, and P-Area Coal Pile Runoff Basins in Relation to Their Host Areas, Pipelines, and Coal Piles, shows the location of each CPRB in relation to its host area. The power plants at A, D, and H Areas are still (1997) in use, but the associated basins and pipelines may be closed in a manner similar to the C-, F-, K-, and P-Area CPRBs when operations are discontinued.

In the removal action performed during the summer of 1997, the coal-laden sediments and soils in the CPRBs at C, F, K, and P Areas were removed under the Removal Site Evaluation Report/Wastewater Closure Plan for the C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (U) (Reference 1) and the basins were backfilled to grade with clean soil. The remaining coal, which was judged to be too weathered for use as fuel, was also removed from the K-Area Coal Pile under this plan. The remaining coal at the P-Area Coal Pile was transported to an active power plant before the removal action began. The coal was removed from the coal pile storage areas in C and F Areas in 1985.

The removal action is summarized in Table II, Summary of the C, F, K and P-Area Coal Pile Runoff Basin Removal Action. The 13,100 tons of coal, coal-laden sediment, and soils were transported to an approved off-site facility, where the material was thermally treated to destroy the coal. The residual material is being used for road base.

Samples were collected from the 0.0-2.0 and 2.0-4.0 foot intervals beneath the proposed clean-out elevation in the F- and P-Area CPRBs. These samples were analyzed for the suite of contaminants of concern associated with coal. This sampling and analysis program confirmed that the removal action was effective in removing the source materials. Samples were also collected from each load of waste before shipment off-site, these samples were archived for possible analysis in the event of litigation arising from the removal, transport, or reuse of the CPRB material.

The C-, F-, K-, and P-Area CPRBs were cleaned out to a planer surface at least four feet below the proposed final grade. All visible coal was removed from the C-, F-, K-, and P-Area CPRBs and the K-Area Coal Pile. The basins were backfilled with at least four feet of clean native soil. This eliminated the source of potential contamination for exposure of future industrial workers and on-unit residents to shallow soils during future excavations at the sites. The action completely removed at least the 0.0-1.0 foot interval which contained the highest concentrations of the constituents of concern in the CPRBs. The backfill was graded to eliminate ponding and to reduce infiltration and the potential for erosion; a vegetative cover was established to prevent erosion.

The buried pipelines, which had conveyed stormwater runoff from the coal stockpiles to the CPRBs, were extended across the backfilled basins at the C-, K-, and P-Area CPRBs since these pipelines are still being utilized to manage the runoff from the former coal stockpiles and surrounding areas. After the coal was removed from the F-Area Coal Pile in early 1985, the pipeline to the CPRB was plugged. The buried reinforced concrete pipeline remains in place.

The C- and K-Area CPRBs have been evaluated under the Resource Conservation and Recovery Act, 1976 (RCRA) Facility Investigation (RFI); Comprehensive Environmental Response, Compensation and Liability Act, 1980 (CERCLA) Remedial Investigation (RI); and Baseline Risk Assessment (BRA) protocols. However, the RFI/RI process for the C-Area CPRB was suspended when the Removal Site Evaluation Report/Wastewater Closure Plan for the C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (U) (Reference 1) was initiated. These investigations demonstrated that toxic metals, radionuclides, and other contaminants in the basins were largely confined to the coal-laden sediments that stormwater runoff carried into the basins as suspended solids from the coal stockpiles. The toxic metals, radionuclides, and semi-volatile compounds were mostly found in the 0.0-1.0 ft interval of coal-laden sediment and soil within the basins.

Conditions in the CPRBs (contaminant suite, distribution of contaminants, and the risks and hazards attributed to these contaminants) are similar because:

• coal from the same sources was used in all of the power plants,
• the CPRBs were all excavated in similar upland soils, and
• management practices for the waste stream to all of the CPRBs were the same.

The RFI/RI/BRA report for the K-Area CPRB (Reference 2) and the preliminary RFI/RI/BRA for the C-Area CPRB document the similarity of conditions in two of the CPRBs. Because of the similarities, it is reasonable to conclude that the contaminant suite, the distribution of the contaminants, and the risks and hazards attributed to these contaminants should be similar. Thus it was not necessary to characterize the F- and P-Area CPRBs as rigorously as the C- and K-Area CPRBs, resulting in a considerable reduction in time necessary to effect remediation of the four basins.

The Removal Site Evaluation Report/Wastewater Closure Plan for the C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (U) (Reference 1) concluded that impacts on local groundwater quality due to the operation of the CPRBs had not exceeded Primary Drinking Water Standards at any of the CPRBs except at K Area.

At the K-Area CPRB, gross alpha has exceeded its MCL (15.0 pCi/L) in nine samples out of a total of 18 analyzed for gross alpha from a downgradient well since the first quarter of 1988. The maximum value for gross alpha was 52.8 pCi/L in the third quarter of 1988; the most recent gross alpha value was 17.5 pCi/L in the first quarter of 1996. The occurrence of elevated gross alpha is sporadic and the levels appear to be generally declining. Gross alpha has not exceeded its MCL in the other downgradient wells. The alpha emitters dissolved in the groundwater may be from the coal or may have been leached from the Coastal Plain sediments by the acidic coal pile leachate; in either case, removing the coal and reducing infiltration will reduce the levels of alpha activity in the local groundwater. Confirmatory groundwater monitoring for gross alpha will be conducted for five years in four existing wells at the K-Area CPRB.

SRS manages certain waste materials which are regulated under RCRA, a comprehensive law requiring responsible management of hazardous waste. RCRA 3004(u) requires that releases from solid waste management units be investigated and remediated as necessary. The CPRBs are solid waste management units regulated under RCRA 3004(u).

On December 21, 1989, SRS was included on the National Priorities List. This inclusion created a need to integrate the established RFI Program with CERCLA requirements to provide for a focused environmental program. In accordance with Section 120 of CERCLA, the U.S. Department of Energy has negotiated a Federal Facility Agreement (1993) with the U.S. Environmental Protection Agency (EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC) to coordinate remedial activities at SRS into one comprehensive strategy which fulfills these dual regulatory requirements.

When proposing the removal action to the EPA and SCDHEC, SRS acknowledged that many tons of waste would be generated as a result of the project. SRS noted that the coal-laden sediment did not have a sufficient BTU value to be acceptable for burning and/or energy recovery. Through the cooperation of the regulators and site personnel it was determined that the coal sediment waste would be otherwise processed for beneficial reuse. This effort marked the first time SRS has recycled a CERCLA waste for public consumption.

In order to meet regulatory agreements and remain consistent with SRS waste minimization goals, a mechanism was needed to ensure the successful subcontractor performing the removal action field work would process and recycle the coal sediments, regardless of the low BTU value. A beneficial reuse clause was added to the contract bid package requiring recycling at an EPA CERCLA Off-site Rule approved facility.

The 13,100 tons of coal and sediments were transported to an EPA and SCDHEC approved facility in Summerville, South Carolina, for thermal treatment. The waste was processed through a rotary kiln at a retrofitted concrete batch plant that is typically used to process petroleum contaminated soils. This burning of the waste successfully treated it so contaminants were bound and could no longer leach to the environment once it was released for reuse by the public. The end product was determined to meet the necessary engineering requirements and standards and was subsequently utilized as a road base material by a road building contractor located outside of Charleston, South Carolina.

The typical method for managing waste generated from this type of removal action is to ship the coal and sediments to an offsite permitted RCRA Subtitle D Landfill Facility that is also approved by the EPA under the CERCLA Off-site Rule. The costs associated with this type of disposal are approximately $70/ton. The cost for recycling the waste was $23/ton. The $47/ton difference allowed SRS to realize a $615,000 beneficial reuse savings which could be allocated to the remediation of other waste units.

Currently, the SRS Environmental Restoration Division is investigating options for recycling other wastes generated from various CERCLA waste units at the site.

While past practices have resulted in no exposure to workers at the CPRBs, future maintenance activities and characterization studies will place workers in this general area. Based on the potential for worker exposure to low levels of metals and radionuclide contaminants, it was recommended that these areas be cleaned-up as a time-critical removal action pursuant to the NCP 300.415 and Section XIV of the FFA.

The coal-laden sediments and shallow basin soils were removed as proposed and dispositioned in a manner meeting regulatory approval. All basins were brought to final grade with at least four feet of clean backfill over the remaining subsoil; the surface was seeded to vegetation for erosion control. During construction, standard erosion control practices were utilized to prevent erosion and possible pollution of surface waters.

The ability to beneficially reuse the coal and sediments from the four CPRBs was the major contributor to obtaining regulator approval for performing the removal action. Other benefits realized as a direct result of gaining this approval are:

• an accelerated remedial action which will improve existing groundwater conditions as it removes the contamination source.
• the remaining basin subsoils were covered with at least four feet of clean backfill, eliminating the direct exposure and excavated soils pathways.
• regrading of the CPRBs eliminated ponding in the CPRBs and reduced infiltration by 44 to 66%.
• a remediation schedule acceleration of 92 months.
• the potential to redirect over $11 M in budget to other waste units, thus expediting future remedial activities.
• the ROD for these four units (C, F, K and P) will be a final "No Further Action" ROD and thus will not require five year ROD reviews.
• the elimination of over twenty five documents scheduled for submittal to the regulators.

1. Westinghouse Savannah River Company. "Removal Site Evaluation Report/ Wastewater Closure Plan for the C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (U)," WSRC-RP-96-897, Revision 1. Westinghouse Savannah River Company; Aiken, South Carolina (April 1997).
2. Westinghouse Savannah River Company. "RCRA Facility Investigation/ Remedial Investigation Report with the Baseline Risk Assessment for K-Area Coal Pile Runoff Basin (189-K) (U)," WSRC-RP-96-125, Revision 1.2. Westinghouse Savannah River Company, Aiken, South Carolina (January 1997).

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