PUBLIC HEALTH ASSESSMENT
OLD SOUTHINGTON LANDFILL
SOUTHINGTON, HARTFORD COUNTY, CONNECTICUT
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
The majority of the sampling data reviewed for this assessment was obtained from the EPA RI/FS performed by GZA Consultants. Data were also obtained from the CT DEP and the Southington Water Company files. During the investigations by GZA on-site and off-site samples were collected from ground water, soils, ambient air, surface water, and surface water sediments.
Sampling for methane in indoor air is being conducted as a follow-up to citizen complaints and because unsafe levels have been detected in commercial buildings. In addition, combustible gases have been detected in residential yards.
In the data tables that follow under the On-site Contamination and Off-site Contamination subsections, the listed contaminant does not mean that it will cause adverse health effects from exposures. Instead, the list indicates which contaminants will be evaluated further in the Health Assessment.
Comparison values for health assessments are contaminant concentrations in specific media that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant guidelines. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons similarly exposed over a lifetime. Maximum Contaminant Levels (MCLs) represent drinking water contaminant concentrations that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of two liters of water per day. Proposed Maximum Contaminant Goals (PMCLGs) are MCLs that are being proposed. While MCLs are regulatory concentrations, PMCLGs are not. The EPA Reference Dose (RfD) is an estimate of the daily exposure to a contaminant that is not expected to cause adverse health effects.
A. THE TOXIC CHEMICAL RELEASE INVENTORY
To identify possible facilities that could contribute to contamination near the site, the l989 Toxic Release Inventory (TRI) was searched. The TRI contains information on total releases of chemicals from certain industries. Only the Lori Corporation located just north of the OSL was listed on the TRI in 1989. The facility reported releasing 250 pounds of copper and 15,000 pounds of trichloroethylene into the air. The TRI did not contain information on any of the commercial facilities located on the landfill.
The TRI does not identify all facilities which may have historically contributed to contamination near the site.
The on-site contamination which is presented in Table 1 through Table 4 include sampling data from ground water monitoring wells, surface and subsurface soils, and indoor air. The data in the tables reflect all contaminants of concern identified and their range of concentrations. These chemicals are those which are present in high concentrations relative to comparison values, and which are known to be toxic. Comparison values are contaminant concentrations in specific media (soil, air, ground water, etc.) that are used to select contaminants for further evaluation.
Ground Water-Monitoring Wells
GZA (1990, 1991) and ESE (1992) sampled 12 on-site ground water
monitoring wells and detected VOCs, semi-volatile compounds
(SVOCs), metals, and PCBs above comparison values. Table 1 lists
those contaminants detected above comparison values.
Table 1.GROUND WATER CONTAMINATION IN ON-SITE MONITORING WELLS(1,2)
| CONTAMINANT | CONCENTRATION RANGE ppb |
COMPARISON VALUE
ppb SOURCE |
|
| Benzene | ND - 27 | 1 | CREG |
| Beryllium | ND - 24.6 | 0.008 | CREG |
| Cadmium | 5 - 14.4 | 7 | EMEG |
| Chromium | ND - 593 | 100 | MCL |
| 1,1-Dichloroethene | ND - 580 | 0.06 | EMEG |
| 1,2-Dichloroethene | ND - 3,000 | 70 | MCL |
| Ethyl Benzene | ND - 710 | 700 | MCL |
| Manganese | 6.2 - 50,500 | 200 | RMEG |
| Naphthalene | ND - 100 | 20 | LTHA |
| PCBs | ND - 8.3 | 0.005 | CREG |
| Di(2-ethyhexyl) phthalate(DEHP) | ND - 78 | 3 | CREG |
| Toluene | ND - 12,000 | 7,000 | RMEG |
| 1,1,1-Trichloroethane | ND - 1,300 | 200 | MCL |
| Trichloroethylene | ND - 11 | 3 | CREG |
| Vinyl Chloride | ND - 3,500 | 0.7 | EMEG |
| CREG | - Cancer Risk Evaluation Guide |
| EMEG | - Environmental Media Evaluation Guidelines |
|
LTHA |
- Lifetime Health Advisory for drinking water |
|
MCL |
- Maximum Contaminant Levels: The level EPA has determined to be protective of public health over a lifetime at an exposure rate of two liters of water a day. |
|
ND |
- none detected |
|
ppb |
- parts per billion |
|
RMEG |
- Reference Dose Media Evaluation Guide |
|
1 GZA 1990,1991 |
|
| 2 ESE 1992 | |
Private Drinking Water
On October 6, 1992, in response to citizens concerns that contaminated groundwater may enter the municipal water mains and contaminate their tap water, the CT DPHAS sampled the tap water at the four homes located on-site. The tap water samples were analyzed for metals, VOCs, and the standard chemicals that water companies are required to test for (i.e. nitrates). No chemicals were identified above health comparison values. The water was found to be hard. Hardness is a measure of the amount of calcium and magnesium in the water. Hardness is not considered to be a contaminant. Drinking water that is hard is believed to beneficial in the prevention of heart disease.
Surface Soil
Forty surface soil samples (0 to 12 inches in depth) were collected and analyzed for metals, VOCs, SVOCs, polyaromatic hydrocarbons (PAH), PCBs, and pesticides. Nineteen samples were taken from the four residential properties (ESE 1992). No contaminants were found in the surface soils above health comparison values.
Subsurface Soil
Approximately sixty-three subsurface soil and refuse samples were collected and analyzed for metals, VOCs, SVOCS, PAHs, PCBs, and pesticides collected by GZA (1990, 1991) and ESE (1992). Several VOCs and PAHs were found above comparison values. The highest concentrations of VOC contaminants were detected on the R.V. & Sons property in 1991.
Subsurface soil samples collected by ESE (1992) identified concentrations of PAHs above comparison values on the R.V. & Sons, Parks and Recreation and on all residential properties. Table 2 lists those contaminants identified above health comparison values in subsurface soils.
Table 2. SUBSURFACE SOIL CONTAMINATION ON-SITE (1, 2)
| CONTAMINANT | CONCENTRATION RANGE (ppm) | COMPARISON VALUE
ppm SOURCE |
|
| Benzene | ND - 1,500 | 20 | CREG |
| Benzo(a)pyrene(PAH) | ND - 690 | 0.1 | CREG |
| Toluene | ND - 16,000 | 10,000 | RMEG-C |
| CREG | - Cancer Risk Evaluation Guide |
|
ND |
- non detected |
|
ppm |
- parts per million |
|
RMEG-C |
- Reference Dose Media Evaluation Guide - Children |
|
1 GZA 1990,1991 |
|
|
2 ESE 1992 |
|
Gas Monitoring Wells
In 1987, methane was found in four on-site gas monitoring wells and within a methane extraction trench installed by GZA at levels between 5 percent and 66 percent by volume of methane in air and above comparison values (25 percent Lower Explosive Limit {percent LEL}), indicating that a condition of gas entrapment, methane migration or both is present beneath the ground surface. The four on-site gas wells and the methane extraction trench are located east of the Northeast Machine and the Parks and Recreation buildings.
Subsurface Soil Gas
As part of the RI/FS, two soil gas surveys, and a survey for combustible gases at 111 locations throughout the site were performed by GZA and ESE.
Four pockets of detectable VOCs were found within the OSL site and neighboring properties by GZA in subsurface soils (RI/FS 1990). VOCs were detected around the buildings of R.V. & Sons, Parks and Recreation, Southington Metal Fabricators and Solomon Casket. VOC readings in exceedance of 1,000 ppm on an HNU screening instrument were measured during subsurface soil drilling in front of the R.V. & Sons Welding building by GZA in 1991. The facility was subsequently evacuated to protect employees from potentially toxic gases and fumes.
No VOCs were detected in subsurface soil gas on the residential properties.
In the July of 1992, a total of 60 subsurface gas samples were taken by ESE in order to assess VOC and methane contamination throughout the site. Samples were also taken from permanent monitoring probes on residential properties. Elevated levels of combustible gases were identified on two residential properties located on the north side of the landfill and in the areas extending from the Parks and Recreation property to the Solomon Casket property (see Figure 3 in Appendix 4 for the location of methane concentrations). Screening for combustible gases (i.e., methane) is performed with a combustible gas indicator (CGI). The CGI is an instrument that measures the percentage of gases that can be combusted in the atmosphere. The results are presented as percentages of lower explosive limit (LEL) of methane. The LEL is the minimum amount of gas required in air by volume to sustain combustion.
Combustible gas readings were identified above the LEL from subsurface (below the surface by at lease 3 inches) measurements taken from the yards of residential properties number 11 and number 12 (see Figure 1-2). Combustible gas readings ranged between 0 and in exceedance of 1,000 percent LEL (see Figure 1-2 ). This suggests that either methane is migrating from the southern areas of the landfill or is being generated naturally from buried organic materials.
Indoor Air
Indoor air sampling for air toxics and methane was performed on a number of occasions. The following paragraphs represent a chronological summary of the indoor air testing that has taken place at the OSL to date.
In 1986, GZA performed air quality monitoring in buildings within the study area for organic vapors, oxygen and combustible gas concentrations. This was done for the protection of on-site workers, nearby residents and businesses. VOCs were found in approximately 25 percent of the 220 samples screened.
In 1990, the EPA took indoor air samples (EPA Sept, 1990) in two homes located within the boundaries of the landfill. These homes were sampled because a study conducted by the EPA in 1985 identified methane in a commercial building located on OSL below the LEL. The concern was raised that methane buildup from the landfill may be present and could act as a carrier gas for other toxic chemicals buried within the landfill. The two private residences selected were located at 413 and 425 Old Turnpike Road. The VOCs detected were below health comparison values.
In November of 1991, the EPA had received the following reports: that workers in the Southington Parks and Recreation Department were becoming ill while inside the building; and that flames had been ignited in cracks in the concrete floor at the Southington Metal Fabricator facility during welding operations.
Subsequently, the Southington Fire Department detected the presence of organic vapors and combustible gases inside and outside of the Southington Parks and Recreation building. The Southington Fire Department obtained LEL readings ranging from 30 to 90 percent, and at least one substance in addition to methane was also detected during their survey in the Southington Parks and Recreation Department facility and Southington Metal Fabricators. The results in Table 3 show the percent LEL of methane detected.
In response on December 12, 1991, the EPA performed indoor air screening for methane and non-methane volatile organic compounds in three residential and nine commercial buildings. The EPA screening results found elevated levels of combustible gases in the breathing zone of three of the nine commercial/industrial facilities tested. No combustible gases were identified above comparison values in any of the three private residences screened.
In June of 1992, OSHA performed indoor air screening and found methane above comparison values (8-198 percent LEL) in two buildings of the Southington Metal Fabricators facility.
In August of 1992, the CT DEP sampled the private residence located at 413 Old Turnpike Road for VOCs and found benzene below comparison values.
In September of 1992, explosive levels of methane (0-70 percent LEL) were identified in the floor cracks of the R.V. & Sons welding shop by the Southington Fire Department. According to the owner of the facility, the level of combustible gases set off the ambient air combustible gas alarm.
In response to the identification of explosive levels of methane in the three commercial facilities, passive venting systems were installed in the summer and fall of 1992 in the following commercial facilities: R.V. & Sons, Southington Metal Fabricators, and Parks & Recreation Department.
In November of 1992, the EPA performed an air monitoring survey for the presence of methane and total VOCs. Samples were collected from the residential properties, two residential methane monitoring probes and from inside the following businesses: Southington Metal Fabricators, Parks and Recreation Department, Northeast Machine, WNTY Radio Station, Solomon Casket, and Meriden Box. High levels of total VOCs and explosive levels of methane were identified in the cracks in the floor of Southington Metal Fabricators. Elevated readings of total VOCs were detected in the Northeast Machine building. These detections may be due to the chemicals used in the facility (i.e. degreasers).
No VOCs or combustible gases were detected above background levels in the other facilities. None of the VOC measurements obtained from the residential properties were above health comparison values.
TABLE 3. RANGE OF METHANE CONCENTRATION IN INDOOR AIR
| LOCATION | CONTAMINANT | CONCENTRATION RANGE (percent LEL) |
COMPARISON VALUE SOURCE (percent LEL) | |
| R.V. & Sons | Methane | 0 - 70 | 25 | OSHA |
| Southington Dept. of Parks and Recreation | Methane | 30 - 1,000 | 25 | OSHA |
| Southington Metal Fabricators |
Methane | 8 - 198 | 25 | OSHA |
LEL-Lower Explosive Limit standard set by the Occupational Safety and Health Administration.
Ambient Air
Past exposures to contaminants in air from previous fires and the open burning of waste cannot be assessed because there are no data available for the years the landfill was in operation.
Ground Water Monitoring Wells
There are approximately forty-six ground water monitoring wells off-site. VOCs, SVOCs, metals, and PCB contamination above comparison values were found in eight wells just west of the site. Table 4 lists those contaminants found above present comparison values.
Analytical testing by Warzyn in 1980 (Warzyn May 1989, p. 32) found two off-site monitoring wells with methylene chloride at 10 ppb and trans 1,2-dichloroethylene at 29 ppb. GZA could not confirm these results on their follow-up sampling of these wells in 1990.
Elevated concentrations of metals were found in off-site monitoring wells near the Lori Corporation facility and may reflect localized contamination and not contamination from the OSL site.
TABLE 4. CONCENTRATION RANGE OF CONTAMINANTS IN OFF-SITE
GROUND WATER WELLS (1,2)
| CONTAMINANT | CONCENTRATION RANGE (ppb) | COMPARISON VALUE (ppb) SOURCE |
|
| Barium | 41.1 - 1,080 | 700 | RMEG-C |
| Benzene | ND - 9 | 1 | CREG |
| Beryllium | ND - 43.5 | 0.008 | CREG |
| Chromium | ND - 1,020 | 100 | MCL |
| 1,2-Dichloroethene | ND - 6,000 | 70 | MCL |
| Ethyl Benzene | ND - 10,000 | 700 | MCL |
| Lead | 113 - 670 | 0 | MCLG |
| Manganese | ND - 38,800 | 50 | RMEG-C |
| Methylene chloride | ND - 10 | 5 | MCL |
| Naphthalene | ND - 100 | 20 | LTHA |
| PCBs | ND - 14 | 0.005 | CREG |
| Di(2-ethyhexyl) phthalate(DEHP) | ND - 700 | 3 | CREG |
| Tetrachloroethylene | ND - 62 | 0.7 | CREG |
| Toluene | ND - 23,000 | 2000 | RMEG-C |
| 1,1,1-Trichloroethane | ND - 1,800 | 200 | LTHA |
| Trichloroethylene | ND - 580 | 3 | CREG |
| Vinyl chloride | ND - 23 | 0.7 | EMEG |
| CREG | - Cancer Risk Evaluation Guide |
|
EMEG |
- Environmental Media Evaluation Guide |
|
LTHA |
- Lifetime Health Advisory |
|
MCL |
- Maximum Contaminant Level |
|
MCLG |
- Maximum Contaminant Level Goal |
|
ppb |
- Parts Per Billion |
|
RMEG-C |
- Reference Dose Media Evaluation Guide -Children |
|
1 GZA 1990, 1991 |
|
|
2 Warzyn 1989 |
|
Ground Water - Public Well
Municipal well number five was found to be contaminated above natural background levels in 1976 and not deactivated until 1979. The well continued to operate until 1979 because there were no water quality guidelines for VOCs when the well was initially identified as contaminated. The well was found to be contaminated with TCA, trichloroethylene, carbon tetrachloride, methane and trace amounts of lead and mercury. PCB contamination was detected by GZA in 1987 during one sampling round (GZA RI/FS Volume III, 1991 ). Table 5 lists those contaminants detected in municipal well number five above present comparison values. Currently there are no public drinking water wells within a mile of the OSL site. In addition, the Southington public water supply is safe to drink.
Ground Water - Private Wells
Low levels of VOCs were detected in two commercial private water wells located just west of OSL. The VOCs include chloroform, l,2 dichloroethene, trichloroethylene, and vinyl chloride. The VOCs detected were found at levels below comparison values and are not considered a health concern. Currently there are no residential drinking water wells in the vicinity of the site. All residential wells in the vicinity of the site have been connected to the public water supply.
TABLE 5. GROUND WATER CONTAMINATION OF MUNICIPAL WELL 5 (1)
| CONTAMINANT | CONCENTRATION (ppb) |
COMPARISON VALUE (ppb) SOURCE |
|
| Carbon tetrachloride | 8.9 | 0.3 | CREG |
| PCB | 1.1 | 0.005 | CREG |
| 1,1,1-Trichloroethane | 300 | 200 | LTHA |
| Trichloroethylene | 45 | 3 | CREG |
| CREG | - Cancer Risk Evaluation Guide |
|
LTHA |
- Lifetime Health Advisory |
|
ppb |
- parts per billion |
|
1 GZA 1991 |
Surface Water
Black Pond and its outlet stream are the main receiving waters for OSL and neighboring properties, collecting surface water runoff from the surrounding roadways, industrial, residential, and commercial properties.
Surface water samples were collected in June of 1990 from Black Pond and the stream into which Black Pond discharges. Iron, hexavalent chromium, and manganese were detected above comparison values and are listed in Table 6. Trace amounts of carbon disulfide were found and are not considered a risk to human health or aquatic life. The aquatic criteria values protect plants and animals. The fish consumption values are protective of human health taking into account the lowest contaminant concentrations from ingestion of water and fish, and the ingestion of fish only.
Surface water samples collected from the Quinnipiac River (GZA 1990) identified minimal levels of VOCs and semi-volatile compounds. Several metals were detected at levels higher than background concentrations in downstream surface water samples. Samples taken in wetland areas (using ground water well points less than 5 feet deep) indicated the same pattern of contamination as described in surface water samples.
TABLE 6. CONCENTRATION RANGE OF CONTAMINANTS IN OFF-SITE SURFACE WATER 1
| CONTAMINANT | RANGE (ppb) | AQUATIC CRITERIA (ppb) |
FISH CONSUMPTION |
||
| Acute LOEL |
Chronic LOEL |
water+fish ingestion |
fish ingestion only |
||
| Carbon disulfide | 4-23 | - | - | - | - |
| Iron | 666 -2,010 | 1,000 | - | 300 | - |
| Manganese | 212-1,000 | - | - | 50 | 100 |
| Chromium | ND-25.95 | 16 | 11 | - | - |
| LOEL | - Lowest observable effect level |
|
ND |
- None detected |
|
ppb |
- parts per billion |
|
1 GZA 1990 |
Fish
In September of 1992, the CT DPHAS and the CT DEP, Inland Fisheries Program caught approximately 200 live fish specimens from Black Pond using a net. All the fish caught appeared healthy. Twenty-five fish were collected from this sample of 200 fish. The remaining fish were returned to the pond. The fish species collected were catfish, yellow perch, bass and white suckers. Composite samples of five specimens from each species were analyzed for metals and PCBs. Trace levels of metals and PCBs were found in the fish below health comparison values.
Stream Sediments
Semi-volatile organic compounds (SVOCs) were found in sediments from the outlet stream to Black Pond and the impounded wetland south of Black Pond. The SVOC concentrations in the sediments ranged from 0.9-l0 ppm. These levels are below comparison values and therefore are not considered a health threat.
Other chemicals identified in the sediments below comparison values include carbon disulfide, phthalates, and furans. The metals detected include cadmium, lead and nickel. The metals detected in sediments occur at natural background levels (Kabata-Pendias and Pendias, l985 ).
Subsurface Soil Gas
Subsurface gas sampling was also conducted, primarily for the protection of workers, as well as the residents and businesses located adjacent to the subject site area. Some boreholes contained VOC levels between 1-3 ppm, and levels between 0-50 ppm were found in a few of the ground water monitoring wells. The VOC levels detected in borehole readings correspond with areas of current industrial operations. Monitoring well results may be explained by the potential for the natural biodegradation of organic matter, or the fact that the PID readings may be skewed by the presence of naturally occurring chemicals, such as hydrogen sulfide (GZA,1990).
Four areas were found to be contaminated with detectable levels of VOCs. These include:
- the southern portion of Chuck and Eddie's Used Auto Parts property,
- east and west of the Solomon Casket Co. building,
- east and west of Old Turnpike Road, and
- north of Meriden Box.
Based on the sampling distribution results, those contaminants detected west of Old Turnpike Road and north of Meriden Box are not likely attributable to past landfill activities, but rather, to present industrial activities ongoing in the sampling areas.
Ambient Air
Past exposures to contaminants in air from previous fires and the open burning of waste cannot be assessed because there are no data available for the years the landfill was in operation.
D. QUALITY ASSURANCE AND QUALITY CONTROL
The Consulting Firms (GZA and ESE) conducting the RI/FS were monitored by EPA oversight personnel, both in field and laboratory procedures. However, the procedures used by these firms or other consultants who have conducted historic sampling at the site were not evaluated by the Connecticut Department of Public Health and Addiction Services. Therefore, the conclusions drawn for this health assessment were determined by the availability and reliability of the referenced information and it is assumed that adequate quality assurance and quality control measures were followed with regard to chain of custody, laboratory procedures and data reporting.
As indicated in Table 5, elevated levels of PCB contamination was detected by GZA in 1987 during only one sampling round (GZA RI/FS Volume III, 1991.) in Town well number five. The levels ranged from ND to 1.1 ppb. However, it should be noted that there exists some controversy regarding the reliability of the data analysis since PCBs were not analyzed for in prior sampling events.
Although no physical hazards were observed during our site visit, methane has been detected in one building at Southington Parks and Recreation, one building at R.V. & Sons, and two buildings at Southington Metal Fabricators. Gas production in landfills is a subject of much concern because of the potential hazards of methane combustion.
Methane was detected in 1986 (GZA 1986) at levels ranging from 0.1 to 2.3 percent Lower Explosive Limit (LEL) beneath the R.V. and Sons building (GZA 1986), and in 1991 and 1992 at dangerously high levels (30 to greater than 1000 percent LEL) in the R.V. & Sons building, the Southington Parks and Recreation building and in two out of three buildings (northernmost and southernmost buildings) of Southington Metal Fabricators.
According to an employee from Southington Metal Fabricators, during the winter seasons, a gas-like odor is frequently detected in the building where welding is commonly performed. In addition, he also stated that cracks in the floor of the facility have ignited when a welding torch was lit.
The CT DEP observed the ignition of floor cracks in the Southington Parks and Recreation building during a site inspection in the summer of 1992.
In July of 1992, the ATSDR performed a health consultation to assess the presence of combustible gases on-site and provide advice for its remediation. The ATSDR health consultation report indicated that due to ceiling height, floor space and adequate daily ventilation of the structures, it is unlikely that enough methane could accumulate in these buildings to cause an explosion or health hazard. However, the report notes that accumulation of methane gases in a small confined space, such as a closet, is possible and could create a dangerous situation (the ATSDR health consultation report is in Appendix 5).
Engineering controls have been installed in 2 facilities (Southington Parks and Recreation and Southington Metal Fabricators) to control the entrance of combustible gases. Steps have also been taken by ESE to seal cracks in these 2 buildings. Combustible gas indicators have been installed in all the commercial and residential buildings on the site. However, cracks in the floors of some of the commercial buildings continue to develop creating new gas migration pathways into the buildings.
Because of the continuing subsidence, the methane levels detected and the fire incidents, the potential exists for methane levels to increase at any time. In addition, the potential exists for methane to migrate into other buildings. Therefore, the potential exists for fire and explosion hazards.
To determine whether nearby residents have been or are being exposed to contaminants migrating from the site the CT DPHAS and the ATSDR evaluated the environmental and human components that lead to human exposures and an exposed population. The pathway analysis consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure and an exposed population. Exposure pathways discussed here are air, soil, groundwater and surface water. For exposure pathways to be completed all five elements of the pathway must be present. Potential pathways are those where there is not enough evidence to show that all the elements are present, could be present or were present in the past.
A. Completed Exposure Pathways
Public Ground Water Wells
Residents were exposed to the contaminated public water supply for an indeterminate period of time. OSL is suspected to have contaminated one of the town production wells located 600 feet from the site. According to various engineering reports, landfill waste sources are suspected to have migrated in the ground water to town well number five. In addition, there are other industrial facilities in the area (Lori Corporation, and Chuck and Eddie's) which could also have been sources of contamination.
A large portion of the population of Southington received ingestion, skin contact and inhalation exposure to water contaminated with VOCs from town well number five. This occurred for an unknown period of time between 1972 and 1979. Southington residents ingested water contaminated with VOCs, and received dermal and inhalation exposures to VOCs when they bathed or washed with water from this well.
Although not site related, town wells 2, 4, and 6 are discussed here because all municipal wells are pumped through the entire water distribution system of the town. Town well 4 was installed in l967, was identified as contaminated with VOCs in l976, and was operated until deactivated in l979. Town well 6 was installed in l976, identified as contaminated with VOCs in l976 and deactivated in l980. Town well 2 was installed in l952, identified as contaminated with VOCs in l982 and deactivated. Subsequently, an air stripper was installed to remove the VOCs contamination and the well is currently in use. As a result, Southington residents were exposed to VOCs when they ingested water contaminated with VOC from these wells. The residents received dermal and inhalation exposure to VOCs when they bathed or washed with water from these three wells. The ATSDR estimates that approximately 30,000 Southington residents received contaminated water from these wells for an unknown period of time.
Indoor Air Pathway
Employees of the Southington Parks and Recreation facility and Southington Metal Fabricators received skin contact and inhalation exposure to indoor air contaminated with methane and other unknown gases migrating from landfill waste source.
Concentrations of combustible gases have repeatedly been shown to exceed comparison values in the floor cracks of three facilities on-site, the Southington Parks and Recreation Department and Southington Metal Fabricators and R.V. & Sons. In addition, employees of the Southington Parks and Recreation have complained of illness (allergic skin reactions, headaches and nausea.)
B. Potential Exposure Pathways
Private Well Pathway
Ingestion, dermal (skin absorption), and inhalation exposures to elevated concentrations of VOCs, or metals may have occurred in the past if the four private wells (three commercial wells and one residential well) in the area were used for drinking or washing. Both Solomon Casket and the one private residence historically used private water wells for drinking water purposes. These two wells have been closed and both the residence and Solomon Casket have been connected to public water. All residential wells in the vicinity of the site have been connected to the public water supply.
An employee of Solomon Casket stated that the well water occasionally had a bad odor and was not ingested during these times. According to the employee the well was principally used for washing trucks.
Although the resident claimed the well was tested for basic water chemistry standards and was declared 'acceptable' this information could not be confirmed.
Inhalation and dermal exposure can occur when contaminated well water is used for both household and industrial purposes, such as showering or hand washing.
Soil Pathway
High levels of VOCs and PAHs were found in subsurface soils on several commercial properties. The compounds found (benzene, ethyl benzene, toluene, and PAHs) are volatile. The potential exists for dermal and inhalation exposures to contaminated soils to occur to persons involved in excavations or digging on the R.V. & Sons property and/or along Old Turnpike Rd near the R.V. & Sons property.
No contaminants were identified above health comparison values in surface soils. Therefore, exposures to surface soils is not considered a cause for concern.
Surface Water Pathway
Residents could potentially receive inhalation, dermal or ingestion exposures to potentially contaminated water or landfill leachate while swimming in Black Pond. Leachate seeps are common along the western shores of the pond and carbon disulfide and a variety of metals have been found in surface water samples.
Ambient Air Pathway
Landfill workers and other persons in the area may have received inhalation exposures to toxic air emissions generated from the open burning of potentially hazardous liquid and solid wastes in the landfill. The estimated period of exposure was from 1920 to 1967. The landfill open burned industrial wastes (solvents, metal sludges, etc.) and spontaneous chemical fires were common, according to an employee from Solomon Casket.
We do not know which chemicals landfill workers and other persons in the area may have been exposed to, since we do not have any ambient air data for the years when the landfill was operating.
Food Chain Pathway
According to local residents and employees, people fish and frog hunt in and along the shores of Black Pond.
The Black Pond surface water sampling results indicate that a number of metals
are at levels above those established under the Federal Clean Water Act Criteria
for aquatic health (freshwater criteria and fish ingestion or fish consumption
only). Therefore, there was concern for potential bioaccumulation of metals
in fish. In response, fish were collected from Black Pond and analyzed for metals
and PCBs. The concentrations of metals and PCBs identified in fish are below
health comparison values and thus are not a health concern.
Completed exposure pathways have been identified for indoor air and ground water. Potential exposure pathways have been identified for soil, surface water, and groundwater. In this section the health effects associated with exposure to contaminants of concern will be discussed.
In this section we will discuss the potential health effects in persons exposed to specific contaminants. To evaluate health effects, the ATSDR has developed a Minimal Risk Level (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer or adverse health effects are not likely to occur. MRLs are developed for each route of exposure, such as ingestion and inhalation, and for the length of exposure, such as acute (less than 14 days), intermediate(15 to 364 days), and chronic (greater than 364 days). The ATSDR presents these MRLs in Toxicologic Profiles. These chemical specific profiles provide information on the health effects, environmental transport, human exposure, and regulatory status. When MRLs are not available for certain chemicals, other comparison values are used to assess the potential adverse health effects associated with exposures. In the following discussion, we used the ATSDR Toxicological Profiles for trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, toluene, benzene, ethyl benzene, benzo(a)pyrene, lead, mercury, and PCBs.
Methane
Methane was detected in the floor cracks of two non-residential facilities on the site at levels that could pose a fire or explosion hazard. The action level for the combustion of methane is greater than or equal to the OSHA 25 percent lower explosive limit (LEL) (or 25,000 ppm.) If the OSHA LEL is exceeded evacuation is necessary. The methane levels measured in the floor cracks in the facilities measured between 30 and 198 percent LEL. However, the methane levels detected in ambient air at the breathing elevations could not cause any adverse health effects. There is no MRL or RfD for methane. Methane is an asphyxiant (will cause suffocation) and has no other health effects.
Methane will cause suffocation at a level of 330,000 ppm (or 33 percent). The levels measured in the breathing levels in homes and in the commercial facilities (7 percent) were considerably lower than the level that would cause suffocation. Therefore, no adverse health effects from methane are expected.
Trichloroethylene (TCE)
Trichloroethylene was found above comparison values in the public drinking water well number five (45 ppb) and in ground water monitoring wells (580 ppb). The well was in operation for approximately 7 years. TCE was also detected in soil gas and in minor amounts in indoor air samples.
TCE exposure through ingestion occurred in the past to persons who drank water from TCE contaminated public well number five (45 ppb). Using the highest TCE concentration detected in the public water well (45 ppb), the ingestion exposure was calculated for adults (1.3 ug/kg/day) and children (4.5 ug/kg/day) did not exceed the ATSDR intermediate MRL (700 ug/kg/day). Therefore, adverse non-carcinogenic health effects are unlikely to occur in those persons who drank TCE contaminated water for one year. We assume that adults drink two liters (66 ounces) of tap water each day for seven years and weigh 70 Kg (154 pounds) For children we assume that they drank one liter (33 ounces) of tap water each day for seven years and weigh 10 kg (22 pounds). Because of insufficient data neither the ATSDR nor the EPA have chronic guidelines for TCE. Therefore, the health effects associated with drinking TCE contaminated tap water for over one year are not known.
Carcinogenicity studies have indicated that an association may exist between leukemia in humans and exposure to well water contaminated with chlorinated organic compounds including trichloroethylene (Kotelchuck and Parker, l979; Parker and Rosen, l98l; Lagakos et al. l986 a,b). The EPA has classified trichloroethylene in Group B2 - probable human carcinogen.
The estimated cancer risk was calculated. The cancer risk estimates calculated for an adult and a child for a seven year period indicate that TCE induced cancer from the ingestion of the TCE contaminated drinking water is unlikely to occur.
1,1,1-Trichloroethane (Methyl Chloroform, TCA)
As indicated in the environmental contamination section TCA was detected in ground water monitoring wells and in the public drinking water supply well number five at levels (300 ppb) above the Lifetime Health Advisory of 200 ppb.
There is no acute or chronic MRL or RfD for TCA. The concentrations of trichloroethane found in the well are below the Lowest Observed Effect Level for ingestion in laboratory animals. Studies have not been performed on the effects of long term exposure on humans to low levels of TCA. Thus, the human health effects resulting from long-term exposure of humans to water contaminated with specific levels of trichloroethane are not known. Therefore, the long term health effects of exposure to trichloroethane in the tap water are not known.
Although TCA was also detected in soil gas samples (ranging from ND to l50 ppb) and in indoor air samples at levels at or above 98 percent of average homes (US EPA TEAM Study, 1987), no adverse health effects are expected from inhalation exposures at these levels.
The main effect of TCA exposure at levels much greater than those found in the public drinking water well and in indoor air is central nervous system depression. Kidney and liver damage are minimal and have not occurred when used as an anesthetic agent.
Carbon Tetrachloride
Carbon tetrachloride was found in ground water monitoring wells and in public drinking water well number five (8.9 ppb) above the ATSDR CREG (0.3 ppb). The calculated dose estimate for an adult (0.25 ug/kg/day) and child (0.9 ug/kg/day) are below the ATSDR intermediate MRL of 7 ug/kg/day. Therefore, adverse non-carcinogenic health effects are unlikely from the ingestion of carbon tetrachloride contaminated tap water from well number five for one year.
The EPA has classified carbon tetrachloride in Group B2-probable human carcinogen. Therefore, the estimated cancer risk was calculated and compared to the ATSDR excess lifetime cancer risk estimates. The cancer risk calculations for an adult and a child for a seven year period indicate that the risk for carbon tetrachloride induced cancer from the ingestion of carbon tetrachloride-contaminated water is not significant.
Toluene
Elevated levels (16,000 ppm) of toluene have been detected in subsurface soils. Toluene was also identified in indoor air at levels ranging from 69 ug/m3 to 2l2 ug/m3. Although these air levels exceed average background levels for toluene in indoor air, adverse health effects from inhalation exposures at these levels are not expected.
Studies have not been performed on the health effects of short or long term exposure to toluene at low levels. None of the available studies suggest that toluene is carcinogenic.
Benzene
Elevated levels of benzene have been detected on-site in subsurface soils and soil gas, in ground water monitoring wells, and in indoor air samples. Benzene in ground water monitoring wells was found at levels (27 ppb) above the EPA MCL of 5 ppb. There is no evidence to indicate that residents have been exposed to benzene in drinking water.
Although the indoor air levels occur at concentrations greater than approximately 90 percent of the average home levels nationally, they are below health comparison values and thus no adverse health effects are expected at these levels.
Subsurface soils were found to contain between 0 and 1,500 ppm of benzene (GZA 1991). Since benzene evaporates into the air, there is a potential for inhalation exposure to benzene during on-site excavations.
Benzene is a known human carcinogen. It has been linked to the development of leukemia and other adverse affects related to the hematopoietic (blood related) system. The indoor air sampling results did not approach this level of toxicity and thus, adverse health effects are not expected.
Ethyl Benzene
Ethyl benzene was detected in on-site ground water monitoring wells (ND to 7,800 ppb) above the EPA MCL of 700 ppb. Ethyl benzene was also detected in soil gas and in indoor air at levels below health comparison values. Thus, no adverse health effects are expected from inhalation exposures to the ethyl benzene levels found on-site and there is no evidence to suggest that residents have been exposed to ethyl benzene in ground water
The health effects of low level exposure to ethyl benzene in the air for short periods of time include eye and throat irritation. One long-term study in animals suggests that ethyl benzene may cause tumors (Maltoni 1985). However, no studies were located regarding carcinogenic effects in humans to date.
Benzo(a)pyrene
Benzo(a)pyrene was found in subsurface soil at levels (4.4 ppm) above the ATSDR CREG of 0.1 ppm. Adverse dermal effects have been noted in humans following skin exposure in patients with pre-existing skin conditions. In addition, benzo(a)pyrene is a tumor promoter. Thus, humans dermally exposed to benzo(a)pyrene together with other chemicals that are carcinogenic may be at risk for developing skin cancer. This may be cause for concern during soil excavation or diggings on-site.
Lead and Mercury
Lead has been detected in ground water monitoring wells in a few locations off-site at levels exceeding the EPA action levels of 15 ppb (identified range ll3-670 ppb) during sampling conducted by Warzyn between l977-l980. In addition, lead and mercury were also detected in three public drinking water wells (4, 6, and 5). Although this contamination is not associated with the OSL site this information is included in this report to assess total metal exposures that could have potentially occurred in the Town of Southington. In addition, it should be noted that there exists some controversy regarding the reliability of the data analysis. Subsequent sampling in 1976 and 1977 did not identify mercury or lead in the three wells. The levels ranged from 7 to 70 ppb for lead which exceeds the EPA action level of 15 ppb. Town well number five had a lead level of 1.8 ppb below comparison values. The levels of mercury (1.8 to 3 ppb) are only slightly higher than the EPA MCL (2 ppb) and exceed the EPA Health Advisory of 2 ppb for lifetime exposure to mercury in drinking water.
Studies indicate that long-term exposure to low levels of lead can cause brain damage and lowered Intelligence Quotient (I.Q.) in children. If a pregnant woman is exposed to lead it can be carried to the unborn child and may cause premature birth, low birth weight, or even spontaneous abortion.
Although not likely to cause adverse effects alone, drinking water levels in the range of 60 to 70 ppb would contribute significantly to the overall body burden of lead and increase the percentage of exposed individuals at risk from lead toxicity due to other sources.
Long-term exposure to either organic or inorganic mercury can permanently damage the brain, kidneys, and developing fetuses. Exposure to mercury at the levels found in the drinking water could put some exposed individuals at risk for some of these long term adverse effects later in life.
Domestic water uses other than drinking (incidental ingestion, inhalation dermal exposure) can increase the potential for chronic health effects from mercury exposure. Mercury has not been shown to be carcinogenic in humans to date.
PCBs
PCBs were found in ground water in public drinking water well number five (Warzyn 1980) after the well was deactivated, and in on-site groundwater monitoring wells above the ATSDR EMEG comparison values. PCBs were only detected in one sampling event after the well had been deactivated. Therefore, it is unknown whether PCB contamination was present during the time the well was operating.
Using the highest concentration of PCB found in well number five (1.1 ppb) the calculated ingestion exposure dose for an adult (0.03 ug/kg/day) and a child (0.11 ug/kg/day) exceeded the ATSDR MRL of 0.02 ug/kg/day. The ATSDR MRL of 0.02 ug/kg/day is for chronic-duration oral PCB exposure. Therefore, since the exposure dose was greater than the MRL for both a child and an adult, the potential exists for noncancerous adverse health effects to have occurred or to occur in residents who were exposed to the PCB-contaminated drinking water in town well number five for over one year. The ATSDR MRL was derived from two studies that showed immunologic effects in monkeys. The studies showed a reduction in antibodies and other proteins that help the body resist infections.
In general, PCBs are easily absorbed through the skin from contaminated soils or other materials. The four major toxic effects of high level exposure to these compounds are chloracne, the wasting syndrome, liver toxicity, and immunotoxicity. Because the possibility exists that the water was contaminated with PCBs, and PCBs are classified as a probable carcinogen the estimated cancer risk was calculated. The cancer risk calculations for an adult and a child for a seven year period indicate that the risk for PCB induced cancer from the ingestion of PCB-contaminated drinking water is not significant.
Currently, the potential for exposure to PCBs at the site is not expected to occur and thus, adverse health effects from on-site PCB contamination are unlikely to occur.
B. Health Outcome Data Evaluation
A number of health outcomes were evaluated for the town of Southington, including cancer, infant mortality, perinatal mortality, learning disabilities, and birth defects. While these analyses may generate clues regarding the association between certain chemical exposures and disease outcomes, it must be stressed that such an association is not considered a causal link. Many other factors may also contribute to the onset of disease, including diet, tobacco use, family history, age, race, occupation, and socioeconomic factors. In sum, the tools of epidemiology are very limited in terms of proving causation because of the complexity of factors that are involved in the development of disease.
1. Results of Tumor Incidence Studies
Two cancer incidence studies have been completed and the third is currently underway. The results of these studies are presented below.
a. Initial study of cancer incidence in Southington 1979 to 1988
Citizen concern prompted the CT DPHAS to conduct a study of cancer incidence in Southington, CT. Data was gathered from the Tumor Registry on tumor incidence for bladder, brain, breast, leukemia, non Hodgkin lymphoma, testis, and all sites combined for the years 1979 to 1988.
Information on the total number of tumors in Connecticut and in Southington was obtained from the Tumor Registry for the tumor sites listed above. Age specific incidence rates per 10,000 population were generated for Connecticut and Southington for the ten year period 1979 to 1988. The age specific incidence rates and standardized incidence ratios were computed for each of the tumor sites bladder, brain, breast, leukemia, and non-Hodgkin's lymphoma, testis and all sites combined. A spreadsheet program was developed to assist in these calculations. A summary of the results is presented in Table 7.
Table 7
SUMMARY OF INITIAL CANCER INCIDENCE STUDY
CONDUCTED BY DPHAS IN SOUTHINGTON, CT 1979-1988
| SITE | OBSERVED EXPECTED |
STANDARD INCIDENCE RATIO |
95 PERCENT CONFIDENCE INTERVAL |
| ALL SITES | 1355 1433 |
0.95 | 0.89, 0.99 |
| BLADDER | 79 76 |
1.04 | 0.80, 1.28 |
| BRAIN | 28 40 |
0.70 | 0.51, 0.87 |
| BREAST | 222 237 |
0.94 | 0.82, 1.05 |
| LEUKEMIA | 34 35 |
0.97 | 0.65, 1.27 |
| NON-HODGKIN's LYMPHOMA |
44 47 |
0.94 | 0.68, 1.20 |
| TESTICULAR | 9 10 |
0.90 | 0.36, 1.49 |
The Standardized Incidence Ratio (SIR) is an overall summary measure of the cancer risk. The SIR is calculated by multiplying the Connecticut cancer incidence rate by the population of the town to estimate an 'expected' number of cancers in each age group. The actual (or observed) number of cases identified by the Tumor Registry are divided by the expected number to obtain the SIR. When the SIR is less than one (1.00) the risk of cancer is less than expected, when the SIR is greater than one the risk is more than expected. This method allows for the inclusion of age as a risk factor in the analysis. Age is important to consider because generally speaking the risk of cancer varies with age.
The SIR did not significantly differ from one (1.00) in most instances. However, the SIR was significantly less than one for brain and for all sites combined. This indicates that Southington as a whole did not experience a higher than expected cancer incidence for the period 1979 to 1988 and in fact the number of tumors was actually lower than expected for most sites evaluated. Review of the ten year age specific rates indicated that only for bladder cancer among individuals between age 40 to 49 did the 95 percent confidence interval indicate a statistically significant elevation in rate.
This preliminary review of the tumor incidence data indicated that there is not a cancer epidemic occurring in Southington. The analysis was based on town wide statistics, however, and did not address the question of whether specific neighborhoods in Southington were experiencing more than their share of cancer. Because there was known contamination of the water supply by emissions from SRSNE a follow-up of this preliminary study was initiated.
b. Follow-up study of bladder and testicular cancer in Southington 1970 to 1989 using Geographic Information System technology
A computerized Geographic Information System (GIS) operated by the CT DEP assisted in the exact mapping of 11 of 12 testicular cancer cases and 125 of the 127 bladder cancer cases that occurred to residents of Southington during the years 1970 to 1989. The GIS was also used to determine where these cases lived in relation to the contaminated public supply wells and to estimate the total number of persons living in relation to the wells so that age specific cancer incidence rates could be calculated.
The use of the GIS allowed the CT DPHAS to analyze cancer rates in geographic areas not defined by town boundaries and to look at smaller geographic areas. Specifically this study focused on a one mile radius surrounding the contaminated public drinking water wells. While the town water supply system contained water that was blended from several sources, this study area was chosen because it was felt that the residents who lived closest to the contaminated wells would receive the majority of their water from these wells.
Estimates of the population in these smaller geographic areas was made relying on data from the 1980 census. The study areas were comprised of one mile radii surrounding each of the public water supply wells. Wells 4 and 6 were combined because of their close proximity.
Standardized incidence ratios were calculated for the study areas. The number of testicular cancers was too small to present any meaningful statistical analysis near the contaminated wells. A summary of the bladder cancer results is presented in Table 8.
OBSERVED/EXPECTED BLADDER CANCER CASES
STANDARD INCIDENCE RATIOS
AND 95 PERCENT CONFIDENCE INTERVALS
IN ONE MILE RADIUS FROM CONTAMINATED WELLS
IN SOUTHINGTON, CT 1970 TO 1989
| Well | OBSERVED EXPECTED |
STANDARD INCIDENCE RATIO (SIR) |
95 PERCENT CONFIDENCE INTERVAL |
| WELL 2 | 7 8.52 |
0.82 | 0.21, 1.43 |
| WELL 5 | 43 31.40 |
1.37 | 0.96, 1.78 |
| WELLS 4 & 6 | 20 16.46 |
1.22 | 0.68, 1.75 |
| WELLS 4, 5 & 6 | 63 47.86 |
1.32 | 0.99, 1.64 |
The population in the one mile radius around well number 2 did not experience an excess cancer risk. The population who lived within one mile of wells number 4, 5, or 6 did experience an excess bladder cancer risk.
This study demonstrated the value of the GIS in enabling the study of the occurrence of disease in relation to a geographic area that is not restricted to political boundaries.
This study did reveal an elevation in bladder cancer among persons living near contaminated wells. However, the study could be improved by developing a better measure of exposure to emissions rather than just the one mile radii around the contaminated wells.
c. Expanded GIS study of exposure to contaminants and cancer incidence in Southington 1970-1989
The ATSDR has funded the CT DPHAS to conduct an expanded study to better assess how residents of Southington were exposed to contaminants from the wells (including well number five near OSL), and contaminants released into the air from SRSNE.
Additional cancer sites were selected for inclusion in the expanded study based on whether toxicological or epidemiological studies had suggested a possible link between exposure to the contaminants found in the drinking water and development of cancer in animals or humans. Cases of liver and kidney cancer and leukemia, lymphoma and Hodgkins disease will be mapped using the GIS. The water distribution system is being evaluated by the ATSDR to develop an exposure ranking scheme. Census blocks will be scored for the amount of water contamination they were likely to have received through the water distribution system. Air contaminants will be similarly ranked. The goal of this study is to compute SIRs for each tumor site by a relative measure of exposure to contaminants in the water and the air and determine if there is a dose/response association between cancer risk and exposure to contaminants.
2. Infant and Perinatal Mortality Rates
Plots of the infant and perinatal mortality rates for Southington reflect elevated rates with respect to the state and surrounding towns for the years l949 to l965 (Appendix 3). It has been theorized that infant mortality rates or miscarriage rates may be sensitive indicators of adverse environmental exposures. Although the present rates are below those of the state and surrounding towns, the historical fluctuation in rates may warrant further detailed investigations with respect to past environmental contamination in the Town of Southington. This may prove to be difficult due to the absence of environmental data from that time period.
Other factors that may play a role in infant and perinatal mortality rates, include the availability of medical care, the occurrence of infectious disease, as well as other data.
C. COMMUNITY HEALTH CONCERNS EVALUATION
On July 1, 1993, the Connecticut State Health Services Commissioner Susan S. Addiss of the Department of Health Services announced the release of the Old Southington Landfill Public Health Assessment (PHA) for public comment. The locations for reviewing the PHA included the Southington Health Department, the Southington Town Hall, the Office of the Southington Town Clerk, and the Southington Public Library. The public comment period was for 30 days beginning July 1, 1993. In response to community health concerns obtained from interviews with local residents and employees of facilities located on OSL, the following discussion provides an evaluation by the ATSDR as well as those actions that have been or will be taken to address the community's health concerns. See appendix five for details of the public comments.
As previously discussed, indoor air sampling performed in homes identified the presence of several potentially toxic gases above background levels which exceeded the average for area homes but did not exceed health comparison values. However, it is difficult to assess whether these gases are generated from the landfill or from household sources (i.e. cigarette smoking, paint cans, and lawn mowers) given the sampling locations. Methane has been identified at explosive levels, in the floor cracks of nonresidential facilities. This suggests that other toxic gases could be migrating into indoor air through the floor cracks as well. Therefore, the CT DPHAS and the ATSDR believe that contamination of indoor air is possible.
As part of the RI/FS the EPA conducted surface soil sampling in order to assess and subsequently remediate any potentially contaminated soils. No contamination was found and thus growing edible plants is not a concern.
In July of 1992, ESE conducted subsurface gas screening for combustible gases from permanent monitoring probes on residential properties. Combustible gas readings were found above comparison values in the yards of residential properties number 11 and number 12. This suggests that either methane is migrating from the southern areas of the landfill or is being generated naturally from buried organic materials. The CT DPHAS does not know if dermal exposure to subsurface gases while gardening, could have caused the resident's skin irritations.
The CT DPHAS and the ATSDR feel that recreational activities taking place at Black Pond could be cause for concern. Although surface water sampling has not detected any significant contamination, carbon disulfide was identified from the water samples taken from the stream into which Black Pond discharges. In addition, during several site visits, state representatives have observed leachate seeping from the western shoreline into the water.
The CT DPHAS did sample fish from Black Pond to assess what potential compounds may be bioaccumulating, and what adverse effects may occur if the fish are ingested. The fish were not found to be contaminated.
The CT DPHAS brought this to the attention of the EPA. The Southington Fire Department responded and found elevated methane gas readings at levels that posed a fire and explosion hazard in the facility. The facility was evacuated and some remedial work was performed which lowered the methane gas levels. In addition, methane monitoring alarms and a passive ventilation system have been installed inside two of the non-residential facilities to ensure safe methane levels.
In addition, the CT DPHAS, the Southington Fire Department and a representative from the Yankee Gas company provided educational training sessions to workers and residents on the dangers of combustible gases and on how to use their methane monitoring alarms. Whether or not the combustible gases seeping into the Parks and Recreation building caused the workers health problems is unknown at this time.
In response to the community concerns, the EPA performed a series of air monitoring rounds for methane and total VOCs in residential and commercial buildings. There were no combustible gases detected in the residences sampled. The VOCs measurements sampled from the residences were approximately equivalent to the instrument background levels.
The CT DPHAS sampled the tap water of those residents that expressed concern. No contaminants were identified and there is no evidence to indicate that there is cause for concern or that the residents' tap water is contaminated.
The EPA RI/FS workers are required by law to wear health and safety equipment while they are on the site performing any sampling or investigative work. If the EPA identified a potential hazard, local residents and workers would be notified and evacuated, if necessary.
Additional environmental monitoring is recommended to determine the possibility that landfill gases are migrating into homes north and east of the landfill, such as 3 homes on the northside of Rejean Road, across from the landfill.
The Southington Fire Department will be advised about the citizens concerns.
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