Rulison Site Semiannual Groundwater Monitoring Report - September 1998 (Uc-700)

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Rulison Site Semiannual Groundwater Monitoring Report Approved for public release; further dissemination unlimited. U.S. Department of Energy Nevada Operations Office

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Available to the public from - U.S. Department of Commerce National Technical Information Service 5285 Port Royal Road Available electronically at http://www.doe.gov/bridge. Available to U.S. Department of Energy and its contractors in paper from - U.S. Department of Energy Office of Scientific and Technical Information

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RULISON SITE SEMIANNUAL GROUNDWATER MONITORING REPORT DOE Nevada Operations Office Las Vegas, Nevada Approved for public release; further dissemination unlimited.

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SEMIANNUAL GROUNDWATER MONITORING REPORT Monica Sanchez, Project Manager Nevada Environmental Restoration Project

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Table of Contents List of Figures ........................................................................................................................................ iii List of Tables.......................................................................................................................................... iii List of Acronyms and Abbreviations iv 1.3 Summary of Site Activities................................................................................................... 1-5 2.0 Sampling and Analysis Procedures .......................................................................................... 2-1 2.1 Groundwater Level Measurement ......................................................................................2-1 4.0 Quality Control Results ................................................................................................................ 4-1 4.1 Field Duplicate Samples....................................................................................................... 4-1 4.2 Equipment Rinsate Blank Samples......................................................................................4-1 4.3 Trip Blank Samples....................................................................................... 4-3

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Table of Contents (Continued) Appendix A - Purge Water Discharge Permit and Letter Terminating

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List of Figures Number Title Page 1-1 Rulison Site Location Map ............................................................................................. 1-2 1-2 Monitoring Well Locations............................................................................................. 1-4 List of Tables Number Title Page 2-1 Rulison Site Groundwater Monitoring Program Sample Container, Preservation, and Analytical Requirements ...............................2-2 3-1 Rulison Site Groundwater Analytical Results Semiannual Sampling, May 1998 ................................................................................. 3-2 3-2 Rulison Site Comparison of Analytical Results for RCRA Total and Dissolved Metals with Mercury, May 1998 ................................. 3-5 3-3 Rulison Site Groundwater Elevations, May 1998 ........................................................ 3-7 4-1 Rulison Site Groundwater Monitoring Program Duplicate Sample Comparison, May 1998 .................................................................. 4-2

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List of Acronyms and Abbreviations U.S. Atomic Energy Commission Austral Oil Company Benzene, toluene, ethyl benzene, and xylenes Constituent(s) of potential concern U.S. Department of Energy U.S. Environmental Protection Agency Matrix spike/matrix spike duplicate National Pollutant Discharge Elimination System Quality Assurance Project Plan Resource Conservation and Recovery Act Surface ground zero Total petroleum hydrocarbons Total dissolved solids Total suspended solids Volatile organic compound

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This report summarizes the results of the May 1998, semiannual groundwater sampling event for the Rulison Site, which is located approximately 65 kilometers (km) (40 miles [mi]) northeast of Grand Junction, Colorado. Following remediation of the drilling effluent pond, groundwater was sampled from wells around the pond quarterly for two years to show that no contamination was migrating from the pond. At the completion of the two years of quarterly sampling a closure report was prepared and submitted to the Colorado Department of Public Health and Environment for approval. Pending approval of the closure report (DOE, 1998), the frequency of groundwater sampling was changed to a semiannual basis. This is the first semiannual groundwater sampling report. The drilling effluent pond was used to store drilling mud during drilling of the emplacement hole for a 1969 gas stimulation test conducted by the U.S. Atomic and Austral Oil Company (Austral). The Rulison Site is located in the north1/* of the southwest V* of Section 25, Township 7 South, Range 95 West of the 6th Principal Meridian, Garfield County, Colorado, approximately 19 km (12 mi) southwest of Rifle, Colorado, and approximately 65 km (40 mi) northeast of Grand Junction, Colorado (Figure 1-1). The site is situated on the north slope of Battlement Mesa on the upper reaches of Battlement Creek, at an elevation of approximately 2,500 meters (m) (8,200 feet [ft]). The valley is open to the north-northwest and is bounded on the other three sides by steep mountain slopes that rise to elevations above 2,927 m (9,600 ft). 1.2 Project Description and Background Project Rulison, a joint AEC and Austral experiment, was conducted under the AEC’s Plowshare Program to evaluate the feasibility of using a nuclear device to stimulate natural gas production in low-permeability, gas-producing geologic formations. The experiment was conducted on September 10,1969, and consisted of detonating a 40-kiloton nuclear device at a depth of 2,568 m (8,426 ft) below ground surface. Natural gas production testing was conducted in 1970 The site was deactivated by the AEC and Austral in 1972 and abandoned in 1976. Cleanup associated with site abandonment consisted of removing all remaining equipment and materials,

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plugging the emplacement (R-E) and reentry (R-EX) wells (Figure 1-2), backfilling the mud pits adjacent to the R-EX well, removing the tritium-contaminated soils, and conducting extensive surface soil sampling and analysis to characterize the radiological condition of the site. Detailed descriptions of the site deactivation and abandonment activities and radiological characterizations are presented in the Rulison Site Cleanup Report (AEC, 1973), the Project Rulison Well Plugging and Site Abandonment Final Report (ERDA, 1977), and the Rulison Radiation Contamination Clearance Report (Eberline, 1977). The drilling effluent pond is an engineered structure located approximately 400 m (1,312 ft) north-northwest of the surface ground zero (SGZ) emplacement well R-E (Figure 1-2). The pond covers approximately 0.5 hectare (1.2 acres) as measured at the top of the berm; it is triangular in shape, and it is approximately 6 m (20 ft) deep from the top of the berm to the pond bottom. The drilling effluent pond was used to store nonradioactive drilling fluids generated during drilling of well R-E, the device emplacement hole. The drilling fluids consisted of bentonite drilling mud that may have contained various additives, such as diesel fuel and chrome lignosulfonate, used to improve drilling characteristics. Most of the drilling wastes were removed from the pond when the site was cleaned up and decommissioned in 1972; however, some drilling fluid was left in the pond. At the request of the property owner, the pond structure was left in place following completion of site decommissioning and was subsequently converted by the property owner to a freshwater holding pond containing aquatic vegetation, amphibians, and stocked rainbow trout. In 1994 and 1995, four pond sediment sampling events were conducted to evaluate the extent of residual contamination from drilling wastes remaining in the pond. Concentrations of dieselrange total petroleum hydrocarbons (TPH) benzene, toluene, ethyl benzene, and total xylenes (BTEX compounds); barium; chromium; and lead were found in pond sediment samples and soil samples taken from an old settling basin located adjacent to the pond. Based on the results of the 1994 and 1995 sampling events, the DOE decided to conduct a voluntary cleanup action at the pond to reduce the levels of TPH and chromium in pond sediments and soils in and adjacent to the pond. The cleanup was completed in November 1995. One upgradient monitoring well, RU-08) were installed around the pond to monitor the effectiveness of the cleanup. A detailed description of pond cleanup and well installation is presented in the Rulison Site Corrective

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Monitoring Well Locations lurtgcs ground ttro How dbaction SCHEMATIC NOT TO SCALE

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1.3 Summary of Site Activities The May 1998 semiannual groundwater sampling event was conducted on May 13,1998, by personnel from IT Corporation representing the U.S. Department of Energy Nevada Operations Office. All five of the wells had a sufficient volume of water to be sampled. The weather was partly cloudy with temperatures ranging from 10 to IS degrees Celsius (°C) (SO to 60 degrees Fahrenheit [°F]). There were occasional wind gusts to approximately 15 miles per hour, and some patches of icy snow on the ground. A high volume of surface runoff was observed entering the pond from the south. Springs and seeps on the southeast side of the pond were also activel> discharging to the pond. Well RU-03 was found unlocked when it was to be sampled. However, the U.S. Environmental Protection Agency (EPA) was on location on May 12 conducting their Annual Long-Term Hydrologic Monitoring Program. Conversations with EPA personnel on May 12 indicated that wells RU-01, RU-02, and RU-03 were all locked when the EPA arrived on location. It was assumed that they left well RU-03 unlocked.

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2.0 Sampling and Analysis Procedures The May 1998 semiannual groundwater sampling event was conducted in accordance with the Rulison Drilling Effluent Pond Site Long-Term Groundwater Monitoring Plan (DOE, 1996a), the Rulison Site Quality Assurance Project Plan, Rulison Site, Colorado (QAPP) (DOE, 1996c), and as described in this section. The National Pollutant Discharge Elimination System (NPDES) permit number COG-310084, that originally guided the discharge of water from the Rulison Pond during activities in 1996, was canceled by the State of Colorado Water Quality Control Division at the request of the DOE (see Appendix A). The official letter canceling the NPDES permit was dated November 18, 1997* however, a cancellation was granted verbally on 2.1 Groundwater Level Measurement Before purging and sampling activities at each well began, the depth to groundwater and total depth of the well were measured. This information was used to evaluate any changes to groundwater flow direction since the previous sampling event. Monitoring wells were purged of stagnant groundwater using disposable bailers. The pH, temperature, and conductivity of the groundwater were taken prior to discharging any water to the surface and then taken at regular intervals thereafter. Purging was considered complete when the groundwater quality parameters stabilized over at least two consecutive readings of pH, temperature, and conductivity. The pH values ranged from 6.8 to 7.6. Temperature of the groundwater ranged from 2.0 to 8.6°C (35.6 to 47.5°F), and electrical conductivity ranged from 277 to 787 microSiemens per centimeter (pS/cm). Water was discharged to the ground surface in the same manner as in previous sampling events. 2.3 Sample Collection and Handling with disposable bottom-emptying bailers. For quality control (QC) purposes, one duplicate sample, one matrix spike/matrix spike duplicate (MS/MSD), and an equipment rinse blank sample were collected during the sampling event. In addition, a trip blank accompanied all volatile organic samples in their shipping container. Samples were containerized and preserved

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as specified in Table 2-1. All containers were certified clean by the laboratory and remained sealed until ready for use. The groundwater samples from the May 1998 semiannual sampling event were analyzed for the parameters listed in Table 2-1. This table is modified from the one included in the Rulison Drilling Effluent Pond Site Long-Term Groundwater Monitoring Plan (DOE, 1996a), and has the same parameters as collected during the fourth quarter 1997 sampling event, but the analytical program was modified to incorporate the most up-to-date EPA analytical method a SW-846 (EPA, 1990). Parameters analyzed for include the constituents of potential concern (COPCs) identified for the drilling effluent pond sediments (TPH; BTEX; and barium, chromium, and lead analyzed through Resource Conservation and Recovery Act [RCRA] total metals). RCRA dissolved metals with mercury were also analyzed for, in order to compare the results with total Rulison Site Groundwater Monitoring Program Sample Container, Preservation, and Analytical Requirements Method Sample Container Minimum Amount of Sample Required 7470A Polyethylene 1 liter 180 days Metals with Mercury 747QA Polyethylene 1 liter 180 days Total Dissolved Solids 'Holding time calculated from verified time of sample collection. Holding time for mercury is 28 days. bU.S. Environmental Protection Agency. SW-846. Test Methods for Evaluating Solid Waste, Physical/Chemical Methods. cResource Conservation and Recovery Act (CFR, 1998) dU.S. Environmental Protection Agency. Methods for Chemical Analysis of Water and Wastes (EPA, 1983) HCI = Hydrochloric acid

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Analytical results for the May 1998 semiannual sampling event, for the pond cleanup COPCs (diesel-range TPH, BTEX, barium, chromium, and lead) are presented in Table 3-1. Samples sufficient water volume to be sampled for the first time during this sampling event. Appendix B contains the laboratory report of the results for all analyses for the May 1998 semiannual sampling event. A review of the analytical data for laboratory method blanks was performed to ensure that the COPC concentrations reported for the groundwater samples were representative of groundwater quality rather than laboratory contamination. The following sections provide a discussion of the May 1998 semiannual groundwater sampling results. Benzene, toluene, ethyl benzene, and xylene were not detected in any of the samples collected for the May 1998 semiannual sampling event. Diesel-range TPH was not detected in any of the groundwater samples from the May 1998 semiannual sampling event. Rulison’s May 1998 semiannual groundwater monitoring samples were analyzed for RCRA total metals with mercury (Table 3-1). RCRA dissolved metals with mercury were also analyzed for during this sampling event, as was done during the fourth quarter 1997. The sample for RCRA dissolved metals was run through a 0.45 micron filter prior to preservation. By comparing the RCRA total metals with the RCRA dissolved metals, it can be determined if the COPCs are dissolved in the groundwater or are associated with suspended solids. Table 3-2 compares the RCRA total metals results with the RCRA dissolved metals results. The May 1998 semiannual groundwater samples for RCRA total metals from all wells, except RU-05, contained barium at levels ranging from 60 to 120 micrograms per liter (pg/L). In the RCRA dissolved metals samples for all wells, barium ranged from 26 pg/L to 110 pg/L. Barium was not detected in well RU-05 in RCRA total metals, but was detected in RU-05 in the RCRA dissolved metals analysis.

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Rulison Site Groundwater Analytical Results Semiannual Sampling, May 1998 (All results in pg/L) | Well First Quarter

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Rulison Site Groundwater Analytical Results Semiannual Sampling, May 1998 (All results in pg/L) Well First Quarter

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Rulison Site Groundwater Analytical Results Semiannual Sampling, May 1998 (All results in pg/L) j Well First Quarter Values In Halles are for the dissolved fraction. Values in bold are the May 1998 sampling event results. U b Analyte not detected above the specified value R « Quality control indicates that the data are unusable (compound may or may not be present). J 3 Reported value Is estimated.

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Rulison Site Comparison of Analytical Results for RCRA Total and Dissolved Metals with Mercury* Well RCRA Total Metals with RCRA Dissolved Metals RU-06A Duplicate barium 120 barium 110 'Constituents that were not detected were not listed. All May 1998 Analytical Results are included in Appendix B. For RCRA total metals, the laboratory detected chromium at 7.3 pg/L in well RU-05; lead in samples from well RU-07 at 44 pg/L, and RU-08 at 64 pg/L; and selenium in well RU-03 at and tier II reviews, these detections were all qualified as non-detects (U) since these values are less than 5 times the concentrations found in the laboratory’s continuing calibration/method blank. Arsenic was not detected in any of the RCRA total metals samples from all five wells. For RCRA dissolved metals, the laboratory detected arsenic at 93 pg/L in well RU-06A; lead was detected in well RU-03 at 52 pg/L, in RU-06A at 48 pg/L, and the RU-06A duplicate at 34 pg/L. These results were also qualified as non-detects (U) during tier I and tier 11 reviews since these values are also less than 5 times the concentrations found in the laboratory’s Table 3-2 compares the analytical results for both the RCRA total metals and RCRA dissolved metals. Only barium, was detected in the filtered and unfiltered samples. This indicates that the barium is dissolved in the groundwater. Concentration trends of inorganics detected in the groundwater at the Rulison Site are addressed in the Rulison Site Surface Closure Report,

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A shallow depth to groundwater was encountered during the May 1998 semiannual groundwater sampling event. Groundwater …