HEALTH CONSULTATION
Review of May 2000 Expanded Site Inspection Data for Manila Creek Landfill
MANILA CREEK LANDFILL
(a/k/a POCA DRUM DUMP)
RAYMOND, PUTNAM COUNTY, WEST VIRGINIA
BACKGROUND AND STATEMENT OF ISSUE
The Region three office of the U.S. Environmental Protection Agency (EPA) requested that the Agency for Toxic Substances and Disease Registry (ATSDR) review environmental sampling data from the latest expanded site inspection (ESI) of the Manila Creek site, and evaluate the health impacts associated with the site [1].
Manila Creek Landfill is located in a wooded, rural area on County Road 5, and it is comprised of one half acre of land that has been used as a disposal area for general organic chemical waste by the Monsanto Company of Nitro, West Virginia, from 1956 to 1957 [2]. There are two streams north and south of the site, Washington Hollow Creek and an unnamed tributary. Both streams flow westward into Manila Creek, which then drains into the Pocatalico River which is confluent with the Kanawha River. The site is fenced by a six-foot chain link fence with a locking gate. Two seep areas are located between Washington Hollow Creek and north of the fenced area. A dirt access road is located on the southern portion of the site, and part of the road serves as a parking area for recreationists accessing an adjacent wildlife management area, which is managed by the State of West Virginia. The closest residences are approximately 0.5 mile away in a nearby hollow [2,3]. The closest town is Poca, WV., approximately 2.3 miles away from the landfill [4] .
Several federal and state government agencies, including the EPA, West Virginia Department of Natural Resources (WVDNR), ATSDR, and a private company (i.e., Monsanto Company) have conducted assessment activities at this site since the 1980s. Analysis of samples taken from a variety of media (e.g., soil, surface water, monitoring well water, leachates, and sediment) revealed the presence of several chemicals. To prevent migration of hazardous substances from the site, under a Consent Agreement, Monsanto performed several remedial activities in 1987 as follows: (1) installed a dewatering well system; (2) constructed a barrier of sheet pilings to divert groundwater around the site; (3) placed a layer of polyethylene liner over the waste area; (4) capped the area with soil and clay; (5) erected a six-foot chain-link fence with a locking gate; and (6) installed three groundwater monitoring wells. In 1999, Monsanto posted warning signs around the contaminated seeps at the request of EPA [1,2].
EPA conducted a dioxin Total Maximum Daily Load ( TMDL) investigation for the Kanawha River, Pocatalico River and Armour Creek in 1999. Manila Creek Landfill is one of several waste sites that are being investigated as a possible sources contributing to the elevated levels of dioxin in the Kanawha River [5].
In addition, EPA also conducted a site inspection (SI) at the site on September 28-29, 1999, to collect information concerning conditions at the site for assessment of a possible threat to human health and the environment and to determine the need for additional investigation. The analytical results of samples collected during the SI are:
Based on the above findings, EPA concluded that "hazardous substances are migrating from the landfill into environment. The surface water migration pathway is the primary release of hazardous substances. Wetlands and the fishery in Manila Creek are being impacted by contamination from the site."[6]
ATSDR reviewed the SI data and concluded that all contaminants, except arsenic, were at very low levels that are not likely to cause adverse health effects. In the sediments of the two seeps north of the landfill, the arsenic levels were elevated above a level of health concern. ATSDR determined that frequent (i.e., daily) dermal contact with the contaminated sediments in these two seeps might result in adverse health effects. However, exposure to these sediments is expected to be infrequent based on the location of the two seeps and the nature of human activities in the area. Infrequent exposures to those sediments are not likely to result in any adverse health effects [3].
In order to document the extent of migration of the contaminants at the site, an expanded site investigation (ESI) was conducted in May 2000. Among the environmental media collected, there were four monitoring well water samples, 31 soil samples, three surface water samples, three sediment samples, and three quality control/quality assurance (QC/QA) samples All samples were analyzed for VOCs, SVOCs, metals, dioxins, PCBs, and pesticides. In September 2000, an ATSDR Record of Activity (AROA) was issued concerning a contaminated soil "hotspot" found just outside the fenced area of the landfill. This area of contaminated soil contained 3 parts per billion (ppb) of dioxin [10]. In this health consultation, ATSDR reviewed the full data set from the ESI, and evaluated potential health impacts of contaminants found at the Manila Creek Landfill site.
ATSDR uses different comparison values such as all of the chemical-specific, health-based standards and guidelines. These comparison values are derived by various government agencies to identify contaminants that require further evaluation for possible health effects. ATSDR has established the following comparison values for evaluating contaminants in the environment: Minimal Risk Levels (MRLs); Environmental Media Evaluation Guidelines (EMEGs); Reference Dose Media Evaluation Guides (RMEGs); and Cancer Risk Evaluation Guides (CREGs). In this health consultation, the ATSDR comparison values (MRLs, EMEGs, RMEGs, CREGs), the EPA soil screening levels, the EPA drinking water Maximum Contaminant Levels (MCLs) and the West Virginia State water quality standard are used. Due to conservative assumptions used in setting those comparison values, it should not be concluded that a level greater than the screening value will necessarily lead to harmful health effects.
ATSDR considers the most likely human exposure at this site is occasional ingestion and/or infrequent dermal contact with contaminated surface water, soils and sediments by persons participating in occasional recreation activities or work. Inhalation exposures were not given further consideration because VOCs are not present at levels that exceed their respective health-based comparison values.
Based on ATSDR's review of the environmental data for the Manila Creek Landfill site provided by the EPA Region III office, the primary contaminants of concern in the surrounding area of the Manila Creek Landfill site are arsenic and dioxin. These chemicals were found in some samples at levels above their respective health-based comparison values. Details of the ESI samples are discussed below.
Monitoring Well and Surface Water Samples
During the ESI sampling round in May 2000, three monitoring well water samples were collected from monitoring wells southwest (MW-05, Sata-3 in Figure 1), west (MW-06, Sata-2 in Figure 1), and north (MW-07, Sata-1 in Figure 1) of the landfill. A duplicate sample labeled MW-08 was also collected from southwest monitoring well. Field blank (FB-2), trip blank (TB-3), and rinsate blank (RB-2) samples were also collected for QA/QC purposes. First, this section will review the organic contaminants detected in the monitoring well and surface water samples, and then it will review the inorganic contaminants detected in these water samples.
The organic chemicals 2,4,5-trichlorophenol, 4-methylphenol, and caprolactam were detected at very low levels in a few of the monitoring well samples (Table 1).In one of the surface water samples, 2,4,5-trichlorophenol was detected, although this result was estimated because the chemical level was lower than the contract-required quantitation limit (CRQL). Pesticides and dioxins were not detected in any of the samples taken from water at the site. All concentrations of the detected organic chemicals are below their respective health-based comparison values.
The concentrations of a number of inorganic metals were found to be elevated in some surface water samples when compared to the background levels. The maximum concentrations of those metals are summarized in Table 2. All of the detected metals, with the exception of arsenic and manganese as noted below, were either at concentrations below or near area background levels or below any applicable health-based guidelines.
One sample (i.e., MW-08) contained arsenic at level of 83.9 microgram per liter (g/L), which exceeds the existing drinking water comparison values for this metal (MCL of 50 g/L, chronic EMEG for child and adult of 3 and 10 g/L, respectively). Six samples (SW-15, SW-17, MW-05, MW-06, MW-07 and MW-08) contained manganese at levels greater than 2,000 g/L. It should be noted that sample MW-08 has the highest concentration of most of the detected metals. However, the groundwater and surface water in this area are not currently used for drinking water, therefore ATSDR assumes that human consumption of this water is unlikely.
Surface Soil and Sediment Samples
Three sediment samples and 31 soil samples were collected outside of the fenced landfill area. Surface soil sample locations are indicated on Figure 1. Three sets of core soil samples were collected where the three new monitoring wells were drilled. Samples SS-20 to SS-23 were from Well # 07 (Sata-1 in Fig.1). SS-24 to SS-29 were from Monitoring Well # 06 (Sata-2 in Fig.1), and SS-30 to SS-37 were from Monitoring Well # 05 (Sata-3 in Fig.1). Two sediment samples (SD-15 and SD-17) were collected from the unnamed tributary south of the landfill. Sediment sample SD-16was collected from the seep on the north side of the landfill.
The concentrations of a number of VOCs, SVOCs, pesticides and PCBs were found to be elevated in some soil samples when compared to the background levels. The maximum concentrations of those chemicals are summarized in Attachment Table 3 from the sediment, surface, and core soil sampling results.
The organic contaminants 2-methylnaphthalene (concentration of 110 g/kg), bis-phthalate (concentration of 83 g/kg), naphthalene (concentration of 72 g/kg), and acetophenone (concentration of 78 g/kg) were detected in sample SD-16. Only one chemical (bis-phthalate, concentration of 150 g/kg) was detected in sample SD-17. Pesticides, PCBs, and dioxins were not detected in any of the sediment samples. All concentrations of the detected chemicals are below their respective health-based comparison values.
It should be noted that bis-phthalate was found in all the soil samples (maximum concentration of 1,100 g/kg) with the exceptions of SS-14, SS-19, SS-24, and SS-28. Pesticides and PCBs were only detected in four soil samples (SS-16, SS-17,SS-18,and SS-19), all of which were collected from the slope of the south side of the dump area. The highest concentration of PCBs (Aroclor-1248 and Aroclor-1254) were found in sample SS-19 ( maximum concentration of 240 and 210 g/kg, respectively). The concentrations of all the detected organic chemicals are below their respective health-based comparison values.
Inorganics were detected in the sediment and surface soil samples. The maximum concentrations of these metals are summarized in Attachment Table 4. All of the detected metals, with the exception of arsenic as noted below, were either at concentrations below or near the area background levels or below any applicable health-based guidelines.
Arsenic was found in all three sediment samples (SD-15, SD-16 and SD-17). The highest concentration of arsenic detected was 245 milligram per kilogram (mg/kg).The estimated area background concentration for arsenic in soil ranges from 16-65 mg/kg [7].The chronic EMEG for a child and an adult are 20 and 200 mg/kg, respectively. Those are concentrations considered to be safe levels of daily human exposure for more than 365 days [8]. However, the most likely exposure to arsenic at the site is considered to be occasional ingestion and/or infrequent dermal contact with contaminated soils and sediments by persons participating in occasional recreation activities or work. This kind of infrequent exposure to the arsenic contaminated sediments is not likely to result in any adverse health effects.
Dioxin was detected in five samples at levels above the ATSDR guideline (Table 5). The highest concentration was found in sample SS-19 which was collected at the southeast corner of the landfill. ATSDR guidelines recommend that if dioxin levels exceed 50 parts per trillion (ppt), further evaluation is needed to assess site specific exposures. For dioxin contamination in residential soil, ATSDR has recommended that at concentration of 1,000 ppt dioxin total toxicity equivalents (TEQs), actions should be taken to reduce or eliminate exposure [9]. It is assumed that soil in a residential yard is readily accessible and that children would come into contact with the contaminated soil on a frequent and long-term basis. However, the most likely human exposures to the hotspot are an occasional ingestion and/or contact with contaminated soils and sediments by persons participating in occasional recreation activities or work. To be conservative, ATSDR recommended to EPA that access to this hotspot be restricted and erosion control measures in this area be implemented [10].
Table 5. Manila Creek Landfill Expanded Site Investigation Soil Samples Dioxin Results Summary (g/kg)
| SS-14 | SS-16 | SS-17 | SS-18 | SS-19 | Health Guideline | |
| Total TEQ | 388.7 | 164.7 | 233.1 | 2,709.1 | 3,047.8 | 1,000 |
ATSDR'S CHILD HEALTH INITIATIVE
ATSDR considers children in the evaluation of all exposures, and the agency uses health guidelines that are protective for children. In evaluating any potential health effects from ingestion, children were considered as a special population because of their size, body weight, frequent hand-to-mouth activity and unique susceptibility to chemicals. ATSDR has taken into account that children may accompanyadults for occasional recreation activities on the site.
Jane Zhu, MPH
Health Consultations Section
Exposure Investigations and Consultations Branch
Division of Health Assessments and Consultation
Reviewed by:
Lora Siegmann Werner, MPH
Regional Representative
Office of Regional Operations
Susan Moore
Section Chief
Health Consultations Section
Exposure Investigations and Consultations Branch
Division of Health Assessments and Consultation
Clement J. Welsh, Ph D, MPH
Health Consultations Section
Exposure Investigations and Consultations Branch
Division of Health Assessments and Consultation
Peter J. Kowalski, CIH
Health Consultations Section
Exposure Investigations and Consultations Branch
Division of Health Assessments and Consultation
Table 1. Manila Creek Landfill Expanded Site Investigation Water Samples: Organic Results Summary (g/L)
| Sample Location | 2,4,5-Trichlorophenol | 4-Methylphenol | Caprolactam |
| CVs (Child/Adult) | RMEG 1,000/4,000g/L |
Not Established | RMEG 5,000/20,000 g/L |
| MW-05 | 1 g/L (J) | ND | 55g/L |
| MW-06 | ND | 3 g/L (J) | 86 g/L (+) |
| MW-08 | ND | ND | 31 g/L |
| SW-16 | 1 g/L (J) | ND | ND |
Note:
CVs = Comparison values.
J = Analyte present. Reported value was estimated because the analyte level was lower than the contract-required quantitation limit (CRQL).
+ = Results reported from 2X dilution.
ND = Not detected.
g/L = Micrograms per liter.
RMEG = Reference dose Media Evaluation Guide.
Table 2. Manila Creek Landfill Expanded Site Investigation
Water Samples: Inorganic Results Summary (g/L)
| Metals | Concentration | Location | EMEG(child/adult) | MCL |
| Aluminum | 51,200 | MW-08 | 20,000/70,000 | None |
| Arsenic | 83.9 | MW-08 | 3/10 | 50 |
| Barium | 1,017 | MW-08 | 700/2,000 (RMEG) | 2,000 |
| Chromium | 94 | MW-08 | None | 100 |
| Lead | 91.9 | MW-08 | None | 15(action level) |
| Manganese | 9,590 | MW-07 | 500/2,000 | None |
| Nickel | 109 | MW-08 | 200/700 (RMEG) | None |
| Vanadium | 108 | MW-08 | 30/100 | None |
| Zinc | 320 | MW-08 | 3,000/10,000 | None |
Note:
EMEG = Environmental Media Evaluation Guideline.
MCL = The EPA drinking water Maximum Contaminant Level.
g/L = Micrograms per liter.
Table 3. Manila Creek Landfill ESI Sediment and Soil Samples
Results Summary (mg/kg)
| Chemicals | Concentration | Location | EMEG(Child/Adult) | EPA SSL |
| Methyl Acetate | 0.004J | SS-13/16 | None | None |
| 2-Hexanone | 0.001J | SS-24 | None | None |
| Acetone | 2J | SS-28 | 100,000/1,000,000 | None |
| 2-Methylnaphthalene | 0.11J | SD-16 | None | None |
| Phenanthrene | 0.067J | SS-16 | None | None |
| Fluoranthene | 0.089J | SS-17 | 20,000/300,000 | 310 |
| Pyrene | 0.084J | SS-12 | 2,000/20,000 (RMEG) | 2,300 |
| Benzo(a)anthracene | 0.045J | SS-12 | None | 0.9 |
| Chrysene | 0.054J | SS-12 | None | 88 |
| Bis-Phthalate | 1.10 | SS-23 | 20,000/300,000 | 46 |
| Benzofluoranthene | 0.048J | SS-12 | None | 0.9 |
| Naphthalene | 0.072J | SD-16 | 1,000/10,000 | 3,100 |
| 2,4,5-Trichlorophenol | 0.84J | SS-18 | 5,000/70,000 (RMEG) | 7,800 |
| 1,1-Biphenyl | 1.70 | SS-16 | 3000/40,000 | None |
| Acetophenone | 0.078J | SD-16 | 5,000/70,000 (RMEG) | None |
| Beta-BHC | 0.013J | SS-14 | 30/400 | 0.4 |
| Alpha-BHC | 0.003J | SS-16 | 400/6,000 | 0.1 |
| Delta-BHC | 0.0038J | SS-16 | 0.5/7 | 0.5 |
| Gamma-BHC | 0.0035J | SS-16 | 0.5/7 | 0.5 |
| Endosulfan II | 0.009J | SS-17 | 100/1,000 | 470 |
| 4,4-DDT | 0.045J | SS-17 | 30/400 | 2 |
| Endrin Kentone | 0.010J | SS-16 | None | None |
| Alpha-Chlordane | 0.0062 | SS-18 | 30/400 | 0.5 |
| Arcolor-1248 | 0.24 | SS-19 | None | None |
| Arcolor-1254 | 0.210J | SS-19 | 1/10 | None |
Note:
J = Analyte Present. Reported value was estimated because the analyte level was lower than the contract-required quantitation limit (CRQL).
SSL= EPA Soil Screening Level.
EMEG = Environmental Media Evaluation Guideline.
RMEG = Reference Dose Media Evaluation Guide.
mg/kg = Milligram per kilogram.
Table 4. Manila Creek Landfill Expanded Site Investigation
Soil Samples Inorganic Results Summary (mg/kg)
|
Metals |
Concentration | Location | EMEG(child/adult) |
EPA SSL |
| Aluminum | 15,200 | SS-22 | 100,000/1,000,000 | None |
| Arsenic | 245 | SD-15 | 20/200 | 0.4 |
| Barium | 476 | SS-31 | 4,000/50,000 (RMEG) | 5,500 |
| Beryllium | 2.4 | SD-16 | 100/1,000 (RMEG) | 0.1 |
| Chromium | 26.9 | SS-30 | None | None |
| Lead | 91 | SS-18 | None | 400 |
| Manganese | 1,980 | SS-24 | 3,000/40,000 | None |
| Nickel | 82.9 | SD-16 | 1,000/10,000 (RMEG) | 1,600 |
| Selenium | 1.2 | SS-30 | 300/4,000 | 390 |
| Thallium | 12.7 | SD-15 | None | None |
| Vanadium | 46.8 | SS-30 | 200/2,000 | 550 |
| Zinc | 361 | SD-16 | 20,000/200,000 | 23,000 |
Note:
SSL = Soil Screening Level.
EMEG = Environmental Media Evaluation Guideline.
RMEG = Reference Dose Media Evaluation Guide.
mg/kg = Milligram per kilogram.
Figure 1. Manila Creek ESI Sample Locations
