1981-10-05 – NRC – RMC Report – Site Visit – West Lake Landfill, St. Louis County, Missouri

1981-10-05 - NRC - RMC Report - Site Visit - West Lake Landfill, St. Louis County, Missouri

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liOoAr REPORT ON SITE VISIT – WEST LAKE LANDFILL ST. LOUIS COUNTY, MISSOURI (j 4°249268 Radiation Management Corporation Midwest Division 3356 Commercial Avenue Northbrook, IL 60062 (312)291-1030 TABLE OF CONTENTS Page LIST OF FIGURES i LIST OF TABLES ii INTRODUCTION 1 SITE CHARACTERISTICS 2 RADIOLOGICAL SURVEY 5 SUMMARY 9 APPENDIX A – Draft Site Survey Plan. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 LIST OF FIGURES West Lake Landfill Aerial Survey External Radiation Survey, Landfill External Radiation Levels at 1 Meter Above Surface, Area 1. External Radiation Levels at 1 Meter Above Surface, Area 2 Location of Air, Water and Soil Samples I- •’) LIST OF TABLES Table I Radon Daughter Air Sample Results Table II Water Sample Results Table III Soil Sample Results INTRODUCTION Iii fI III I1I I. INTRODUCTION In September and November, 1980, Radiation Management Corporation (RMC) visited the West Lake Landfill in St. Louis County, Missouri. The purpose of these visits was to obtain sufficient data to allow RMC to prepare a detailed site radiological survey plan. This survey has been scheduled for spring 1981, and is designed to clearly define the radiological conditions at West Lake Landfill. All work has been performed under Letter Contract: NRC-02-20-034 (Radiological Evaluation of Burial Grounds) between RMC and the U.S. Nuclear Regulatory Commission (NRC). Two visits have been made to this site, the first of which occurred on Sep tember 24th. During this visit RMC met site personnel, discussed past, present and future site activities, performed a visual inspection of the site, and arranged for a second, more detailed site visit. This second visit took place November 12-14, 1980. The visit had been delayed over one month due to ongoing landfill operations in an area of interest to RMC. During the second visit, a series of preliminary radiological measurements were made. These measurements included external dose rates, grab air sample evaluations and water and surface soil analyses. The purpose of these measurements was to better define the location of buried material, and to demonstrate that no significant radiological hazards to site personnel exist at this time due to the buried material. As a result of these visits, two extensive areas of contamination have been defined on the landfill site. These areas are not normally occurpied, with one exception as noted in the report. Based on preliminary measurements, RMC concludes that radiation exposures to site workers are minimal. ri rt II. SITE CHARACTERISTICS Although extensive studies of the West Lake Landfill site characteristics have not yet been completed by RMC, the preliminary visits have yielded the basic site information provided below. The radiological history of the site has been traced through discussions with site personnel and review of documents obtained from the NRC, State of Missouri and St. Louis area firms and agencies. (A) Site Profile The West Lake Landfill is located on St. Charles Rock Road just west of the Tausig Road intersection in Bridgeton, MO. The site is about one (1) mile northwest of Route 270 and approximately 1*5 miles east of the Missouri River. It is located in a combined rural-industrial area, and is bounded on three sides by farm land and on the fourth by St. Charles Rock Road, beyond which are located several commercial and industrial establishments. The nearest residential area is a trailer park located about 3/4 of a mile southeast of the landfill. The site is approximately 200 acres and consists of a quarry, stone and limestone processing and storage areas, and several active and inactive landfills. The sanitary landfills are open to the public anytime during normal working hours. West Lake Landfill keeps track of entries for the purpose of assessing fees for disposal, however access is not controlled for any other purpose. J n Preliminary discussions with the Missouri Department of Natural Resources n confirm that at least a portion of the site is within the Missouri River I floodplain. In addition, alluvial ground water level appears to be very near the surface in this area. These considerations prompted the Missouri Geological I. Survey, in 1973, to propose to classify the site as hazardous under the then 1 1 current operating procedures. In addition, samples from perimeter monitoring wells taken in 1977 and 1978 indicated some movement of leachate into those i wells, based on chemical (not radiological) analyses. However, recent studies by the Department of Natural Resources indicate little or no surface or sub- I surface movement of leachate from the site. Leachate from the active sanitary _ landfill is collected in an observation well, pumped to trucks and transported • to a sewage treatment plant in St. Louis. At this time, there is no evidence | of significant ground water contamination, although geological reports indicate a potential for such problems. 1 p (B) Site Radiological Hisotry I In June 1976, the St. Louis Post-Dispatch printed a story alleging that radio3 active material had been erroneously dumped in the West Lake Landfill in 1973. The source of this material was identified as the Cotter Corporation, Hazelwood J . Missouri, Latty Avenue Site. I I An NRC investigation conducted by Region III in 1977 concluded that about q 7 tons of UsOe, contained in 8700 tons of barium sulfate leachate, had been mixed with about 39,000 tons of soil at Latty Avenue and the entire volume disposed of at the West Lake Landfill. The earlier study by the Post-Dispatch (1976) claimed only 9000 tons (presumably the barium sulfate leachate) had been buried, and that the remaining material had not been disposed of at West Lake. The Post-Dispatch alleged that the contractor hauling the dirt had admitted falsifying invoices for about 40,000 tons of soil. Discussions with the site superintendent, Mr. Vernon Fehr, have indicated that he recalls the specific shipments and could accurately locate the material. No records were kept of the disposals, but Mr. Fehr recalled that a large quantity of material was dumped, although he doubted it totaled 40,000 tons. A fly-over radiological survey (ARMS flight) performed in 1978 showed external radiation levels as high as 100 uR/hr in the area indicated by Mr. Fehr as containing the Latty Avenue material. In addition, this survey revealed another possibly contaminated area in a fill previously believed to be “clean”. Mr. Fehr is certain Latty Avenue material was not dumped in this second “hot” area. Apparently the second area is at least 10 years old, and no one had any idea what radioactive material might be present there. Figure 1 shows the results of the 1978 aerial survey. The area in the southeast fill is believed to contain Latty Avenue material, while that on the northeast boundary was previously unidentified. RADIOLOGICAL SURVEY ;r if r i I r i r r c r J III. RADIOLOGICAL SURVEY AND EVALUATION (A) Methods and Measurements 8 A series of measurements and samples were taken on and near the site over a three day period in November 1980. These measurements were designed to estimate I the extent of on site contamination, to evaluate possible existing radiological hazards to site personnel, and to make a preliminary assessment of the possible movement of material off site. Based on these measurements and known site characteristics, a detailed site survey plan has been developed to precisely define the site radiological conditions. External gamma dose rates were used as an indication of the extent of buried material. Measurements were made with a 2″ by 2″ Nal detector and an end window GM tube, at a height of one meter above ground. Nal count rates were converted to yR/hr exposure rates using a previously established factor for radium and daughters in soil. The GM tube was used only in areas where levels exceeded the range of the Nal detector. A series of particulate grab air samples were taken on site, in the areas of highest external radiation levels, and inside one building. These samples were counted for gross activity within one hour and again several days later. The short lived activity was attributed to radon daughters, and working levels were calculated from these activities. Water samples were collected from the leachate observation well, from two freshly dug monitoring wells at the site perimeter, and from a pond located just north of the site. These were analyzed for gross alpha and radium activity. Several surface soil samples were also collected. These came from the berm along the northwest boundary and were taken where the external radiation survey indicated possible surface or near surface activity. These have been analyzed for gamma activity in an effort to identify the contaminants in this previously unknown burial. (B) Results Figure 2 shows the West Lake Landfill and the two areas of buried material. As can be seen, the on-site ground measurements reveal that the initial fly over survey mislocated the actual contamination slightly. Both contaminated areas are located north and east of the aerial survey locations. The burial identified as Area 1 is located along the southern edge of the site access road, extending from the eastern boundary of the fill to the recently constructed parking lot. The total area of readings above background is about 112,00 ft2(2.6 acres). Two areas where levels exceeded 100 uR/hr were identified, each about 7500 ft2(0.2 acre each). The highest levels measured in Area 1 were about 200 uR/hr. A detail of this area is shown in Figure 3. The second burial, Area 2, is shown in Figure 4. This area extends along the Northwest boundary of the site, starting at the boundary berm and extending into the site as far as 300 feet in some directions. The total area of readings above background in this case is about 360,000 ft2(8.3 acres). This estimate assumes that contamination extends under existing stone and gravel piles, where readings could not be made. The highest levels recorded were 5 mR/hr, along the berm in a normally unoccupied area. The fill containing Area 1 is. known to extend to a depth of 30 to 40 feet. The radioactive material is presently covered with an estimated 6 feet of fill, and the operator is planning to cap and seed it shortly. This fill is known to be essentially a sanitary fill, containing no industrial waste or construction or demolition materials. The fill is located over a quarry, and the fill leachate is collected from the quarry floor via a sump well located in the northeast corner of the landfill. Approximately 50,000 gallons of leachate are collected each day and sent to the Metropolitan St. Louis Sewer District Bissell Point Plant. The landfill containing Area 2 is older and less is known about it. However, it is certain that large objects such as building rubble are buried there, along with quantities of rocks from the quarry. In addition, it appears possible that some toxic chemicals (PCB’s, dioxane, etc.) may be buried here. This fill extends to 30-40 feet and is placed on top iof existing land.. Ground water monitoring wells are located near this fill, at the property boundary. Grab air samples were taken in five locations during the site survey. Gross activities were counted 35 minutes after sampling and working levels calculated using a modified Kuznetz method. Samples were taken at the location of highest external radiation levels in an effort to represent the worst case conditions. Measured levels ranged from 0.014 WL to 0.038 WL. Results are shown in Table I. A total of four water samples were collected. Two were taken from monitoring wells dug by the Missouri Department of Natural Resources in October, 1980, one from the on-;site leachate observation well and the final from a pond near the site. These sampling locations are shown in Figure 5, and the analytical J results shown in Table II. Monitoring Wells 3 and 4 were sampled since they are in the general direction of movement of ground water from the landfill. In general, all off-site levels are within EPA drinking water standards (al though these standards do not apply here) and there is no evidence of conta minant movement through water off site for these preliminary measurements. Soil samples were taken at three locations in and around Area 2, in an effort to identify the contaminants in this area. These were surface samples, taken at sites where external radiation measurements indicated the possibility of surface activity. One sample was taken at a hot spot on the berm, a second from loose dirt where a road has been dug through the berm, and a third from the field adjacent to the site berm. Results are listed in Table III and show that elevated concentrations of uranium and daughters exist in soil on the landfill (Area 2) site. No unusual levels were detected in the off-site field soil, and no isotopes other than naturally occuring radionuclides were detected in any of the samples. Activities in the “hot spot” sample were so high that quantitative determinations using the initial analytical techniques were not possible, and further analyses will be required. SUMMARY IV. CONCLUSIONS Two areas of apparently buried contamination have been identified. The first (Area 1) is located immediately south of the landfill access road and comprises about two (2) acres. The second (Area 2) is along the northeast boundary and totals about eight (8) acres. Material in Area 1 is believed to have come from the Latty Avenue site, and would therefore contain uranium ore (UsOe) in barium sulfate leachate. Material in Area 2 is also known to contain uranium and daughters, and is therefore similar to Latty Avenue residues, although the origin of this material cannot be substantiated. Several normally unoccupied areas of the landfill have external radiation levels in excess of 20uR/hr, the target criteria for remedial action. Working levels in these areas may approach MFC for unrestricted areas, based on very limited sampling data. There is no initial indication of movement of material via ground water off site. One occupied facility has been located on an area where material has apparently been buried. This is the Shuman Equipment Service Building on the north section of the landfill. External exposure rates inside the building range from 15 to 50yR/hr, while radon daughter activities are estimated to be near MFC for unrestricted areas under some circumstances. Results of this preliminary site visit have been used in the development of the Draft Site Survey Plan which appears in Appendix A. i’:-r FIGURES AND TABLES •’ t I I 1 I tdttMBB 0 4OO 800 1200 1600 2000 FEET 0 100 200 300 400 500 600 METERS I-HTIMATHD LANDFILL OUTLINE wnnr LAKE LANOFIU AERIAL SURVEY ISOPLETHS onoss COUNT CONVERSION SCALE OAMMA EXPOSURE RATE* LETTER 1 m LEVEL LABEL JliR/tnl A -• C 8-10 o 10- 13 C 13-17 r 17-24 o 24*33 M 33-49 1 4S-82 J •2-84 K 84-11* ritio.or-viiw AT «o m ALIITUDI AND IXTRAPOLATCO TO THC 1 m LEVEL. INCLUDES J.7 fiH/kr COSMIC RADIATION. FIGURE 2 DOERNAL RADIATION SURVEY, LANDFILL A FIGURE 3 1 1 EXTERNAL rtADIATION LB/ELS AT 1 HFTER ARWF qiRFAPf. All readings are in pR/hr. Bkgd. 10 pR/hr. pR/hrv AREA 1 25 ft. x 25 ft. grid pattern L] J 1 • 1 Ali readings are viR/hr. BXgd. = 10iiR/hr. RADIATION LfVELS AT 1 rtlER ABWE SURFACEN AREA 2 5 >! >lOO(jR/hr. ^ ^ >SOOyR/hr. 30 ft. x 30 ft. grid pattern * j FIGURE 5 <*> LOCATION OF AIR, WATER AND SOIL SAMPLES ca Table I Radon Daughters Air Samples Results Sample1 Location Area 1 near road Date S Time Nov.13,8:45am ConditionsDry, wind S-lOmph60*F Working Level 0.017WL Area 1 over highest external level Nov.13,10:30am Dry, wind S-lOmph62 °F 0.014WL Area 2 over highest external level Nov,13,2:45pm Dry, wind S-lOmph70°F 0.019WL Area 2 over suspected Nov.13,3:07pm Dry, wind S-5mph 0.038WL surface material 70°F Inside Shuman Equipment Nov.14,7:35am Bid sealed overnight 0.031WL Service Bid no ventillation Table II Water Samples Collected in October and November 1980 – Results Sample # Location Leachate Observation Well Sample Well #3 Sample Well #4 Settling Pond (1) RMC (2) ANL (3) Missouri DNR Activity Gross a < 7.3 Gross 6 80121 Ra-226 1.0910.29 (2) Gross a 15.612.6 pCi/1 (2) Gross 6 41.314.3 pCi/1 Ra-226 0.610.1 pCi/l(3) Gross a 2.910.7 pCi/l(2) Gross B 7.612.0 pCi/l(2) Ra-226 0.510.1 Ci/1^ Gross a < 2.9 Gross B < 26.3 Table III Soil Sample Results Sample Location Activity pCi/g(dry) Area 2 over suspected Pb-214 PresentM surface material Bi-214 Ac-228 Pb-212 U-235 U-238 Th-227 Ra-226 Th-228 Roadway from berm to Pb-214 4.5EI ± 4, 5EO offsite field Bi-214 3.3EI ± 3, 3EO Ac-228 1.2E1 ± 6.3E-1 Pb-212 3.5E1 ± 3.8EO U-235 1.6E1 ± 1.6EO Th-237 2.3E1 ± 3.0EO K-40 1.3E1 ± 2.3EO Ra-226 3.3E1 ± 3.3EO U-238 Present(2) Off-site field Bi-214 4.1EO ± 4.1E-1 Ac-228 9.6E-1 ± 4.3E-1 U-235 1.5 EO±3.8E-1 U-238 Present(2) K-40 2.2E-1 ± 8.3E-2 Ra-226 4.1E1 ± 4.1E-1 Th-228 1.4E1 ± 5.2E-1 Pb-214 5.3E1 ± 5.3E-1 (1) Activity too high for quantitative determination using initial counting method. Levels are greater than 100 pCi/g for Bi-214 and Pb-214. (2) No quantitative determination of U-238 was made. 'r j: _ f f -.. DRAFT SURVEY PLAN FOR THE WEST LAKE LANDFILL Draft Survey Plan for the West Lake Landfill I. INTRODUCTION Based on preliminary site visits and predetermined survey criteria, a comprehensive radiological survey plan for the West Lake Landfill site has been prepared in draft form for review. The objective of this survey is to define the present radiological status of this site. Based upon the survey results, the Nuclear Regulatory Commission will perform engineering evaluations to determine if remedial actions are required. To this end, survey measurements are designed to determine the identity, concentration and extent of contaminants on site, and whether these contaminants are moving off site. Several types of measurements are required for this survey. These proposed measurements are listed below and described in the following paragraphs. Survey Methods A) Measurement of External Gamma Exposure Rates and Beta-Gamma Dose Rates B) Measurement of Surface Radioactivity C) Measurement of Subsurface Radioactivity D) Measurement of Water Radioactivity E) Measurement of Airborne Radioactivity Al II. SURVEY METHODS (A) Measurement of External Radiation Levels The two areas of contamination which have been previously identified will be gridded and surveyed for both gamma radiation levels at one meter above the surface and beta gamma levels at the ground surface. The basic pattern at each contaminated area will be survey blocks defined by a 10 meter grid system. External gamma levels at one meter will be recorded at each grid point (i.e. at each intersection of two grid lines). Initially, precise gamma measurements at a few specially selected grid points will be made with sensitive Tissue Equivalent lonization Chamber System. At the same time, Nal scintillation detector measurements will be made and a conversion factor for the Nal count rate versus yR/hr established. Once this factor is confirmed, the scintillation detector will be used for all grid measurements at relatively low exposure rates. For higher rates, an ion chamber type portable survey instrument will be used. At each grid point, an end window G-M tube will be used for surface measurements. An open and closed window reading will be made at 1 cm, and the ratio of the two used to indicate surface contamination. A more closely spaced grid (i.e. 5 meter) will be employed to define known hot spots or where evidence of non-representativeness is presented. A2 (B) Measurement of Surface Radioactivity Based on the external surface measurements, surface soil samples will be collected for analysis. This sampling is not considered likely in Area 1, since it is known that buried radioactive material has been recently covered with sanitary fill and capped with "clean" dirt. Therefore, surface deposits are highly unlikely in this area, and were not detected during the preliminary site visit. However, preliminary measurements in the older fill area (Area 2) indicated the possibility of surface deposits, and these will be investigated. Samples to a depth of a few inches would be collected and analyzed. Surface drainage ways will be evaluated wherever the possibility exists that radioactive materials have been carried or washed away from original storage or burial locations. Again, the most probable area of concern is Area 2, where the probability of surface deposits exists and where the dike enclosing the landfill on the north and west is failing. Here, water may be seeping through these faults. Surface drainage is not apparent in the vicinity of Area 1, with the possible exception of some drainage along the landfill access road. Vegetation on site consists only of grass and common weeds. Off site, crops are grown on farm land immediately north and west of the site, adjacent to Area 2. Since the possibility of contamination exists here, crop samples will be collected where indicated by surface measurements. A3 (C) Measurement of Subsurface Radioactivity Since it is known that most, or all, of the radioactive material at the West Lake Landfill has been buried, extensive subsurface monitoring and sampling will be requried. This activity will consist of drilling and lining holes in and around the known contaminated areas. The purpose of this activity is to determine the depth and lateral extent of subsurface deposits. The principle measurement method will be in situ gamma spectroscopy. Each hole will be "logged" using an intrinsic germanium (IG) detector coupled to a computer based multichannel analyzer. Field analyses can then be made, both qualitatively and quantitatively, thereby eliminating time consuming laboratory analyses and expensive core sampling of each hole. Measurement intervals may range from 6" to 24", depending upon factors such as hole depth, activity, etc. An occasional core sample will be taken to verify the in situ measurements and to confirm the presence or absence of non-gamma emitting nuclides such as Th-230. The exact number and depth of holes cannot be determined at this time, since these will depend to some degree upon the extent of subsurface contamination and the characteristics of the fill. Initial estimates would be based on external measurements made during the preliminary site visit. These measurements indicate that Area 1 is about 2 acres and Area 2 about 8 acres. It is known that material in Area 1 is covered with about 6 feet of sanitary fill and clean dirt. Little is known about the material in Area 2, except that this is an industrial fill with large, solid objects such as rocks, boulders and building rubble. A4 Based on this information, it is believed that drilling and sampling will be relatively simple in Area 1. It is possible that as few as 10 bore holes would define this contamination. It is likely that more will be required for Area 2. (D) Measurement of Radioactivity in Water Wherever possible, water samples will be taken from the bore holes. Additional leachate samples will be collected, along with off site pond water. Samples will also be collected from existing site monitoring wells and those which the Missouri Department of Natural Resources might dig. Run off water will be collected is possible. There are no flowing streams which border the site. (E) Measurement of Airborne Radioactivity Measurements will be made to determine whether the material buried on site is a source of airborne radioactivity. The isotopes of concern are Ra-226, Ra-224 and/or Ra-223, which decay to Rn-222, Rn-220 and Rn-219. This may result in the emanation of radon from the soil, and movement of radon and daughters off site. These measurements will be designed to determine Rn flux emanation as a source term for off-site dose calculations. Additional on site Rn daughter measurements will be made to verify preliminary working devel (wl) determinations. Radon flux measurements which are to be related to off-site dose calculations are of no value for Rn-219, due to its very short (4 sec) half-life. Therefore, only the long-lived daughters are of concern for off-site exposures. In addition, if the parent (Ra-223) is not within a few millimeters of the surface, it is not likely to emanate into the atmosphere. AS Due to these considerations, only Rn-222 and Rn-220 fluxes will be measured. The principle measurement technique will be to collect a filtered gas sample from an accumulator and count it in a radon gas analyzer (scintillation cell). Sequential alpha counting, starting immediately after sampling, will allow separation of Rn-222 from Ra-220 (if present). Numerous samples will be taken from various locations during the survey period, in an effort to reduce the effect of fluctuations between individual measurements due to varying meteorological and soil conditions. If Rn-219 proves to be of concern, its daughter can be determined by collection of a particulate filter paper and subsequent gamma counting. This sample „ can be collected from the accumulator simply by circulating the accumulator * air through a filter and back into the accumulator. The sensitivity will be | limited by the relatively short half-life of the daughters and small volume of the samples. Alternatively, the presence of Rn daughters can be determined I by a or v spectroscopy of high volume particulate samples. 1 However, Rn daughter measurements in the presence of all three Rn parents are difficult or complex to measure in the field, even with spectrometry. The proposed method is for total working levels to be measured directly, from the integral of all short-lived radon particulate-attached alpha emitting daughers. Since the purpose here is to determine exposure, a series of measurements at several locations will be made during the 2 month field project to determine average concentrations. This will be done using simple manual techniques and external counting. A6 III. SURVEY INSTRUMENTATION AND EQUIPMENT The specific instrumentation employed may vary slightly with survey require ments, nevertheless certain items are known to be required and have been dedicated to this survey. These are described below. External gamma exposure rates can be measured precisely to 1 or 2 uR/hr with the Tissue Equivalent lonization Chamber system, which consists of 16 liter Shonka chambers and Keithley vibrating capacitor electrometers. Portable survey instruments include Eberline and Johnson rate meters, sealers, GM tubes, alpha scintillators and Nai detectors and Victoreen ion chambers. Sample gamma analysis will be performed with a 20cc intrinsic germanium (IG) detector and Tennecomp TP-50 computer based MCA system. Bore hole logging will be accomplished with a second IG detector, with a specially adapted cryostat and dewar assembly, and a Tracer-Northern 1750 MCA system. Radon gas will be counted in an EDA Radon Gas Analyzer. If alpha spectro scopy is required, a system such as the Tennelec TC 256 will be used, together with one of the MCA's. This instrumentation, along with various laboratory items such as ovens, drying lamps, sample containers, balance, etc.'will be placed in two mobile vehicles for movement on site. Since one goal of this survey is to determine if remedial action is required, it will be necessary to be able to measure levels established by the NRC as target criteria for remedial action. The lower limits of detection (LLD) have been defined as 20% of target criteria and are shown below. A7 Soil Contaminants Nuclide Target Criteria LLD Ra-226 5pCi/g IpCi/g Total U 15pCi/g 3pCi/g U-238 30pCi/g 6pCi/g U-235 30pCi/g 6pCi/g Th-232 5pCi/g IpCi/g Th-230 15pCi/g 3pCi/g (Criteria for Th-232 assume equilibrium with daughters) Water and Airborne Contaminants Nuclide Target Criteria LLD All MFC Unrestricted 20% MFC External Radiation Nuclide Target Criteria LLD All 20 uR/hr 4yR/hr This survey plan has been designed to provide rapid field evaluations of the radiological status of the West Lake Landfill, and to provide the data needed to determine if remedial actions are necessary. Initiation of this survey is scheduled for early spring, 1981. A8