PUBLIC HEALTH ASSESSMENT
HAGEN FARM
STOUGHTON, DANE COUNTY, WISCONSIN
The Hagen Farm site is an abandoned landfill in Dunkirk Township, Dane County, Wisconsin. The site is located at 2318 County Trunk Highway "A", Dane County, Wisconsin. The site was operated as a sand and gravel mining operation prior to the mid 1950's. The site was used for the disposal of both industrial and municipal wastes in the early 1960s. Accurate records of disposal periods and wastes disposed at the site do not exist. Sampling of on-site monitoring wells by the Wisconsin Department of Natural Resources and Waste Management of Wisconsin, incorporated, during the period 1980-1986 indicated that groundwater was contaminated with organic compounds. Groundwater contamination has been identified travelling to the south-southwest. The primary contaminants of concern in the groundwater are tetrahydrofuran and vinyl chloride.
It is believed that persons may have ingested contaminated drinking water from the site in the past, however, there is no documentation of the exposure. At present there appears to be no public exposure. Because of remedial actions taking place at the site future exposures are unlikely. There currently are no drinking water supplies contaminated from this site. A drinking water advisory was placed on the well of a local business near the site. This advisory was put into effect when early groundwater investigation indicated that the well could be at risk of contamination. This drinking water advisory is still in effect. However, further groundwater investigations have shown the well to be outside of the contaminant plume's migration path. The advisory is currently being reconsidered.
The site presents no public health hazard because there is no current exposure and the two residents who experienced past exposures no longer live on the site. A public health hazard would exist if contaminated groundwater migrates to private drinking water wells in the future. Planned remedial activities are expected to adequately address these potential exposures.
The Wisconsin Division of Health, in cooperation with the Agency for Toxic Substances and Disease Registry, will conduct the following activities to respond to the recommendations of this assessment:
In cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR), the Wisconsin Division of Health (WDOH) has evaluated the public health significance of this site. More specifically, WDOH has determined whether health effects are possible and will recommend actions to reduce or prevent possible health effects. WDOH, located in Madison, Wisconsin, is a state agency within the Wisconsin Department of Health and Social Services. This document is prepared for the Division of Health Assessment and Consultation in ATSDR.
A. Site Description and History
The site is an abandoned landfill located in the watershed of the Yahara River in southeastern Dane County. The City of Stoughton is about one mile west of the landfill (Refer to Figure 1 for site location). The site is in the northeast quarter of the southwest quarter of section ten, Town 5 North, Range 11 East, Dunkirk Township. The topography is gently rolling, sloping regionally towards the southwest. Surrounding land use is a blend of rural agricultural and rural residential. There are several sand and gravel mining operations in the area. The Stoughton Air Field is adjacent to the northwest border of the property. County Trunk Highway "A" (C.T.H."A") borders the site to the south and southwest.
The site itself is ten acres on a 28 acre parcel owned by Waste Management of Wisconsin, Inc. (1). A six acre portion of the site has been determined to be the contaminant source area of concern. Disposal in this area consisted of a combination of municipal wastes from the area and industrial wastes from Uniroyal (then U.S. Rubber Company). Prior to waste disposal the site was a sand and gravel mining operation (11). Excavated areas have been backfilled with wastes in the landfilling process. Figure 2 is a general site map.
The land surface slopes towards the southwest at and near the site. Surface water drainage follows the slope of the land towards the Yahara River, approximately 1.5 miles southwest of the site.
Surface soils in the region are silty loams underlain by silt, sand and gravel. Soil types located to the northeast of the site are generally unstratified and unsorted mixtures of gravel, sand, silt, and clay (15, pg.7). The unconsolidated zone of sand and gravel ranges from 50 to 80 feet in depth near the site. The eastern border of the site appears to be a shallow topographic valley with hydric soils and related vegetation (1).
The site is located behind a recessional moraine (Milton Moraine) two miles northeast of the site. Glacial outwash now present at the site was deposited between Glacial Lake Yahara and the end moraine to the northeast (15, ppg. 7-13). A bedrock valley associated with the pre-glacial Yahara River is located two miles west of the site. Sandstone bedrock generally slopes to the west and the southwest from the site towards this pre-glacial valley. The site itself appears to be perched on a local bedrock high, tilted from the northeast to the southwest. Bedrock slopes to the west, south and east off of this bedrock high. The upper layer of bedrock is a very fine to fine grained dolomitic and glauconitic sandstone. The lower part is fine to coarse grained dolomitic sandstone. The weathered portion of the upper layer of bedrock is fractured, forming channels for groundwater movement. These fractures diminish significantly with depth (1).
The groundwater table is less than ten feet from the bottom of the wastes. Sand and gravel glacial outwash separates the waste from the water table. Regional groundwater flow is to the south and west towards the Yahara River. Groundwater flow from the site flows to the south-southwest across C.T.H. "A", generally following topographic features. The upper sand and gravel aquifer is considered continuous with the upper portion of the sandstone aquifer. A shale layer appears to be continuous and confining beneath the upper portion of the sandstone bedrock aquifer. This layer shows up on well logs for monitoring wells installed at and around the site (1, Appendix B).
The site was operated as a sand and gravel pit prior to the late 1950's. The gravel pit was then used for disposal of waste material from the late 1950's to the mid 1960's. Available records and interviews with former employees revealed that wastes from Uniroyal were disposed on site beginning in 1962 and continuing through August of 1966 (10, pg.3). The former disposal area encompassed approximately 5 acres of land located in the southwestern portion of the site which previously had been used as a gravel quarry. The site consisted of one main disposal and two smaller disposal areas. These areas had been covered with soil and the area was vegetated with grasses and 10 to 15 foot tall trees. The disposal areas have since been consolidated and covered with a new clay cap. Documentation of waste quantities is not available (1). Waste disposed of at the site may include solvents, other organic materials (acetone, 2-butanone 1,2-dichloroethylene, vinyl chloride, and tetrahydrofuran), and scrap vinyl. In a 103(c) notification submitted to the United States Environmental Protection Agency (EPA) by Uniroyal, Inc. in June of 1981, Uniroyal indicated that an undetermined quantity of F003 and F005 wastes were disposed of at the site (10, pg.3). EPA Hazardous Waste Number F003 includes the following spent non-halogenated solvents: xylene, acetone, ethyl acetate, ethylbenzene, ethyl ether, methyl isobutyl ketone, n-butyl alcohol, cyclohexanone, methanol and the still bottoms from the recovery of these solvents (2). F005 includes the following non-halogenated solvents: toluene, methyl ethyl ketone, carbon disulfide, isobutanol, pyridine and the still bottoms from the recovery of these solvents (2).
The waste hauling firm City Disposal Corporation contracted with Uniroyal to haul waste to the site beginning in late 1962. Information provided by City Disposal and WMWI suggests City Disposal, now part of WMWI, stopped hauling waste to the site during 1966. Documentation of waste quantities hauled to the site during this period of operation is not available (1).
At the time waste disposal was occurring, the property was owned by Henry and Nora Sundby, since deceased. The property was purchased from the Sundbys by Orrin Hagen in the early 1970s, and by the present owner, WMWI, in 1987. In October of 1980 Mrs. Hagen indicated that a fire broke out on site after they had purchased it from the Sundbys. They were burning lumber and had subsequent underground explosions. This fire lasted for ten days (5). No additional information is available on this alleged fire.
On May 29th, 1981 a DNR inspector accompanied Mr. Hagen to a site where a drum had been found. Mr. Hagen had removed the drum from his field and pulled it out near the roadside. Mr. Hagen attempted to open the bung but could not. The DNR inspector noted a solvent odor close to the drum and determined that the drum was full (13). The contents of the drum were analyzed for proper disposal. The drum contained primarily xylenes, bromoform, and tetrahydrofuran.
In response to complaints received from local residents, groundwater sampling was conducted by the WDNR beginning in November of 1980 and continued periodically through October 1985. Private water supply wells and on-site monitoring wells were sampled by Uniroyal during the period August 1982 through October 1986. Sampling of private water supply wells was later conducted by the United States Geological Survey (USGS). Sampling of on-site monitoring wells during the period 1980 to 1986 indicated organic contamination in the groundwater at the site. Table three is a summary of results from those sampling rounds (1).
The principal method of disposal employed at the site appears to have been dumping liquid wastes out of drums into the gravel pit, allowing the liquids to percolate into the soil. Some containers, such as drums and cans, may have been dumped intact in the pit and in other locations on site, based on WDNR records. However, no drum trenches were discovered during the RI field activities (1).
Several hydrogeologic investigations were conducted at the site. A contractor for a potentially responsible party conducted an investigation in 1982. The contractor installed nine groundwater monitoring wells, including two well nests, at the site. At that time groundwater flow was determined to be to the southeast (1).
In 1984 the USGS conducted a Geophysical investigation to determine the location and distribution of buried wastes. This was followed by another investigation that included the installation of 19 addition monitoring wells. Six of these wells were sampled and benzene, chlorobenzene, tetrahydrofuran (THF) and xylenes were detected in some of the wells. At that time local groundwater flow was determined to the south, east and west immediately beneath the site and to the southwest regionally (1).
EPA assessed the site for Superfund eligibility. A Preliminary Assessment was performed for EPA, by WDNR, in 1984 as part of EPA's Superfund site assessment process. A Site Inspection was then performed by an EPA contractor. Because of changing knowledge of the site and a change in EPA's Hazard Ranking System (HRS), HRS scores were developed on five occasions. The site scored 38.07 in April of 1985. The cut off score for Superfund eligibility is 28.5. The site was subsequently proposed and listed on the National Priorities List (1).
In September of 1987 WMWI and Uniroyal entered into an Administrative Consent Agreement with the U.S. EPA to conduct the Remedial Investigation and Feasibility Study at the site. Field work on the investigation began at the site in the summer of 1988.
The remedial investigation has been completed. The source control portion of the remedial action has already taken place. This activity included consolidating and capping the wastes. The landfill cover and other areas of bare soil have been fully vegetated. A six-foot high security fence topped with three stands of barbed wire and posted with warning signs has also been installed around the capped landfill.
In the spring of 1992, a pilot study was conducted to aid the design of an in-situ vapor extraction system. The pilot study was completed in August 1992. The results of this study were used to complete the design and installation of the full-scale system. In addition, a gas extraction well was replaced and five more gas extraction wells were added. Also, gas probes were installed to monitor any gas migration that may occur in and around the landfill.
A site status update was conducted in the spring of 1994. The investigative design work has been completed to develop the cleanup procedure for existing groundwater contamination. The soil vapor extraction system is operational and a private well monitoring program has begun.
A site visit was conducted on May 25, 1988 by the DOH. At that time the gate to the site was open, and the access road was used by the gravel company while the site visit took place. Numerous areas of dried, crumbling naugahyde scraps buried in the soil were observed. There were no other visible signs of past waste disposal on the site. The area was gently sloping, with small depressions. All soils had a vegetation covering and tree growth did not appear stunted. The neighboring land was also fenced, with no visible access to these areas (11).
Since 1988 the site has undergone considerable change. The construction of the cap has been completed, significantly altering former site features. For this reason an additional site visit was conducted to support this Health Assessment.
On Wednesday, January 22, 1992 a WDOH employee went out to the site. Three representatives of WMWI were present as well as their consultant. The site visit consisted of a walk over portions of the site as well as an update of completed and planned work activities. The following is a summary of observations from the site visit:
The cap is completed. All former disposal areas have been consolidated into the main disposal area near County Trunk Highway "A". The cap has been properly sloped. Access is restricted by a chain link fence. The fence is kept locked unless there are workers on site. At the time of the visit, it was noted that the actual fenced area had been reduced in size to the perimeter of the main disposal area. Areas no longer restricted include the borrow area adjacent to the east and the former secondary disposal areas adjacent to the north and northeast. The waste from these areas has been consolidated to the main disposal area (8).
Runoff controls have been incorporated into the cap design. A sediment basin has been constructed adjacent to the site. This basin has been designed to manage the additional surface water drainage from the cap. The basin will allow surface water to overflow in a diffused manner, thus reducing erosion potential (8).
The site itself has been cleared of vegetation as part of the cap construction. Monitoring wells are located virtually across all of the site. In spring of 1992, gas extraction wells were installed on the cap. The eastern border of the site is a slight topographic valley. Tall grasses and willows cover this narrow strip (8).
A WDOH employee revisited the site in September 1993. The site was capped with a vegetative cover. As stated previously, the soil vapor extraction system was in operation,
C. Demographics, Land Use and Natural Resource Use
Prior to legal negotiations between residents and responsible parties, there were two occupied homes adjacent to the site (1). These homes were generally side gradient from the site. Those houses have been removed and the residents have relocated away from the site. Mr. Hagen used the property for grazing sheep. Subsequent file review indicated that Mr. Hagen drank water from the livestock well and had reported developing cysts on his skin as a result (12). It has also been alleged that another man used the livestock well for potable drinking water. It can not be determined how long this person was living on site (13). Attempts to locate Mr. Hagen recently have not been successful. There are six residences within 1500 feet of the site. Household size for the area is estimated at 2.7 persons per residence (3). At the time of disposal operation and until the mid-1980s, two additional residences existed adjacent to the site. Local private water supplies are drawn from the sand and gravel aquifer or the sandstone bedrock aquifer (1).
According to census projections for the zip code, which includes both the site and the City of Stoughton, 98.8% of the population is white and 0.3% black. There are approximately 17,563 people within the zip code based on projections for 1989 (3).
Land use in the area around the site is mixed residential, agricultural and light industrial. There is a sand and gravel mining operation to the south of the site, across County Trunk Highway "A". There is also an insulation business across C.T.H. "A" from the site. There are additional gravel pits to the north of the site. A local airport is also located to the north of the site. Farm fields are located adjacent to the eastern portion of the site, across the intermittent stream (8).
The Yahara River located downgradient of the site is used for fishing and general recreation. The Yahara River then flows into the Rock River. Neither of these surface waters are in danger of receiving contaminants from this site. This pathway is discussed in the exposure pathway section of this document.
"Health outcome data" is a phrase referring to records of death and disease. When there is evidence that people near a site have been exposed to contaminants at levels that could lead to an increase in rates of death or disease, a review of health outcome data may be appropriate. A review also may be appropriate if there are reports of unusual clusters of disease near a site.
No review of health outcome data has been done for this public health assessment. A review of the birth defects registry was done in 1988 for the preliminary health assessment (11).
Existing community health concerns were established through direct contact with individuals in the area of the site. Persons present at previous public meetings were contacted as those most likely to have health concerns. The town clerk was contacted and reaffirmed that the proper persons were called. The following is a list of the concerns that were raised (Similar concerns were combined where possible):
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
This section describes the extent of contamination and physical hazards associated with the Hagen Farm site.
On-site contamination includes the main disposal area itself and the portion of the groundwater contaminant plume beneath the site (12). The two smaller disposal areas north and northeast of the site have been consolidated with the main disposal area. The original boundaries of waste disposal are not clear because of lack of documentation. For this reason "on-site" is considered the property within the fenced area. After the new cap was constructed, the fenced area was reduced to include only the consolidated waste disposal area (8).
Soils
Ten refuse soil borings were collected during test pit excavations in April of 1990, to further characterize waste. The refuse borings found plastic sheeting, paper, paper-coated plastic, paint sludge, grease, rubber and miscellaneous municipal wastes. Test pit excavations found both municipal and industrial wastes similar to those found in the refuse borings. Other wastes encountered in the main disposal area included industrial scrap vinyl and plastic. Refuse samples were not analyzed for volatile organic compounds (VOC) because the sample matrix precluded complete filling of sample containers (1).
The disposal area was believed to be 14 to 18 feet in depth at the time of disposal. Wastes were taken from the City of Stoughton as well as from Uniroyal (then U.S. Rubber Co.). Wastes believed to have been disposed were municipal wastes, solvents, other organic materials, and vinyl.
The site has been completely covered with a clay cap. For this reason surface soils are not contaminated and surface water runoff from the site does not come in contact with contaminants. Two surface water samples were collected to assess the potential for contaminant migration off site via the surface water route in the past. Samples were taken from the intermittent drainage area east of the site and from Sundby Pond to the south. These samples were analyzed for VOCs, though none were detected (1, Appendix D4). Past migration of VOCs cannot be assessed with present sampling because of the volatile nature of the contaminants. However, these surface waters are not expected to have been impacted by the site.
A soil gas survey was done which detected VOCs in the unsaturated zone in the main area as well as in the two smaller disposal areas. The detections were more frequent in the main disposal area. VOCs detected in this analysis were: acetone, benzene, toluene, 2-hexanone, ethylbenzene and xylenes (1, Appendix D7). These results are not quantitative measurements. There is potential for gas migration from the site to the air pathway. Gas extraction wells were installed in spring of 1992 to assess gas production and VOC contaminants beneath the cap. Methane gas production is common at landfills containing municipal wastes. Other contaminants in the landfill could volatilize and migrate with the methane gas. This landfill is relatively small and did not accept a large volume of municipal wastes. This reduces the potential for the site to produce a significant amount of methane gas. Four ambient air and headwell vapor samples were collected to assess the potential air migration pathway on November 21-22, 1988. The results of this sampling effort are not usable because the samples were held too long prior to analysis (1, Appendix D9). No sampling has been done to assess contamination in surface soils on-site. The site and the cap are now well vegetated.
Groundwater
Four rounds of groundwater sampling were conducted between December 1988 and March 1991. Groundwater samples were taken while drilling test borings. Groundwater samples were analyzed for VOCs and tetrahydrofuran (THF), semi-volatile organic compounds, pesticides, polychlorinated biphenyls, metals and cyanide as well as water quality indicator parameters. During subsequent rounds only VOCs and THF were analyzed in each groundwater sample (1, Appendix D2-3). Tables 1 and 2 summarize sampling results for the four rounds of groundwater sampling. These sampling rounds took place on the following dates: December 13, 1988; September 6-11, 1989; July 31 - August 2, 1990; and March 20, 1991 (1, Table 6-1).
The groundwater beneath the site is contaminated with VOCs from the site. The on-site groundwater contamination extends from beneath the fill area to the south-southwest. Groundwater contamination extends beyond the site boundary and CTH "A" (See Figure 3 for horizontal extent of contamination).
The high contaminant concentrations indicated in this table are from wells located directly beneath the waste. These concentrations are much higher than those of the groundwater migrating downgradient.
Table 2 lists the inorganic parameters that were detected at elevated levels in on-site groundwater.
TABLE - 1: On-Site Organic Groundwater Sample Results
| Compound | Range Detected Units (ug/L) | Comparison Values |
| Volatile Compounds | ||
| Acetone | 4.0-14,000 | 1,000 RMEG |
| 2-Butanone (MEK) | 15.0-4,400,000 | 200 LTHA |
| Ethylbenzene | 2.0-4,400 | 700 LTHA |
| Toluene | 1.0-2,700 | 1,000 LTHA |
| Xylenes(total) | 4.0-37,000 | 10,000 LTHA |
| Tetrahydrofuran | 1.4-630,000 | None |
| Vinyl Chloride | 4.0-77.0 | 0.2 EMEG |
| 1,2 Dichloroethylene | 1.0-9.0 | 70 LTHA |
| 1,1 Dichloroethylene | 1.0 | 0.058 CREG |
| Chlorobenzene | 40.0 | 200 RMEG |
| Chloromethane | 100 | 3 LTHA |
| Vinyl Acetate | 1.0 | 200 RMEG |
| Benzene | 8.0 | 1.2 CREG |
| Semi-Volatile Compounds | ||
| Phenol | 23.0-5,600 | 4,000 LTHA |
| 4-Methylphenol | 12.0-6,100 | None |
| 2, 4 Dimethylphenol | 5.0-1,200 | 200 RMEG |
| Benzoic Acid | 2.0-29,000 | 40,000 RMEG |
| 4-Chloro-3-methylphenol | 7.0 | None |
| Napthalene | 7.0-13.0 | 20 LTHA |
| Diethylphthalate | 5.0 | 5,000 LTHA |
| Bis (2-ethylhexyl) phthalate | 3.0-31.0 | None |
| Di-n-octylphthalate | 5.0 | None |
| 1, 4 Dichlorobenzene | 10.0 | 75 LTHA |
| Benzyl Alcohol | 26.0 | None |
| Bis (2-chloroisopropyl) ether | 19.0 | 300 LTHA |
Source - (1, Tables 6-2,6-3,6-4,6-5)
TABLE - 2: On-Site Inorganic Groundwater Sample Results
| Contaminant | Highest Concentration (Units ug/L) | Comparison Values (Units ug/L) |
| Arsenic | 31.2 | 3 RMEG |
| Barium | 1,570 | 700 RMEG |
| Iron | 165,000 | None |
| Lead | 997 | 15 Action Level |
| Manganese | 3,300 | 1,000 RMEG |
| Cadmium | 35.6 | 2 EMEG |
| Chromium | 109 | 10,000 RMEG |
| Mercury | 6.5 | 2 LTHA |
The high contaminant concentrations indicated in this table are from wells located directly beneath the waste. These concentrations are much higher than those of the groundwater migrating downgradient.
Private Wells
Table 3 lists the contaminants detected in private wells analyses. These analyses took place prior to 1983. Well 1 was the on-site livestock well. Wells 2 and 3 served two homes adjacent to the main disposal area on-site. Well 4 is off-site, though included here because it is the only other private well with a past contaminant detect. The contaminants detected in well 2, 3, and 4 are suspect because of the lack of quality control measures taken at the time of the sample analysis. Detection of contaminants in these wells has not been confirmed in subsequent sampling. Wells 1, 2, and 3 have been abandoned and sealed. Well 4 is only used for non-potable process water. Well 1 is the only well believed to have been within the area of potential impact from site contamination (see Figure 4 for well locations).
TABLE - 3: Contaminants Detected in Private Wells (Units ug/l)
| Compound |
1 |
2 |
|
4 |
Comparison Values |
| Acetone | 150 | Detect | 27 | 34 | 1,000 RMEG |
| Vinyl Chloride | 102 | 0.2 EMEG | |||
| Butyl Acetate | Detect | Detect | None | ||
| 1,2 Dichloroethylene | 400 | 70 LTHA | |||
| Trichloroethylene | 0.6 | 5 MCL | |||
| Tetrachloroethylene | 0.4 | 0.2 | 5 MCL | ||
| Tetrahydrofuran | 2200 | 10 | 69 | None | |
| Xylene (total) | 38 | 10,000 LTHA |
"Detect" indicates that the compound was detected, though not quantified or confirmed due to poor data quality.
Contaminants of concern in groundwater based on exceedances of screening values or the lack of an applicable screening value are listed in Table 4.
TABLE - 4: CONTAMINANTS OF CONCERN FOR THE HEALTH ASSESSMENT
|
|
|
|
| Acetone | Benzyl Alcohol | Arsenic |
| Benzene | Bis(2-ethylhexyl)phthalate | Barium |
| 2-Butanone | 4-Chloro-3-Methylphenol | Cadmium |
| Chloromethane | 2,4-Dimethylphenol | Iron |
| 1,1-Dichloroethylene | Di-n-octylphthalate | Lead |
| Ethylbenzene | 4-Methylphenol | Manganese |
| Tetrahydrofuran | Phenol | Mercury |
| Toluene | ||
| Vinyl Chloride | ||
| Xylenes(total) | ||
| Butyl Acetate | ||
| 1,2-Dichloroethylene |
The VOCs detected in groundwater were predominantly THF, ethylbenzene, and xylenes. THF was detected most frequently and at the highest concentrations at the site. The occurrence, concentration and distribution of THF suggest a plume originating in the south-central section of the main fill area extending south-southwest approximately 2000 feet (1, Figure 22). Relatively high concentrations of THF have been detected in piezometers downgradient of the site. Other VOCs have also been detected at lower levels and a shorter distance from the site.
Existing off-site contamination has been documented in the groundwater flowing from the site beneath the road and traveling to the south-southwest. Contamination in the groundwater has travelled both horizontally and vertically with groundwater flow. The contaminants at the site are less dense than water. However, they are sinking in the aquifer due to displacement from infiltrating rainwater runoff. Figure 4 is based on sampling results for tetrahydrofuran. While other contaminants have been detected off-site, THF has spread to the greatest extent. Contaminants at this site have reached the bedrock beneath the unconsolidated portion of the aquifer. A thin layer of shale provides a confining layer at the site between the upper bedrock aquifer and the lower bedrock aquifer (See Figure 4 for vertical extent of contamination)(1, Appendix B).
The list of off-site contaminants is not as large as those found on-site. In
addition contaminant concentrations decrease with distance from the source.
TABLE - 5: Private Wells Sampled
| Distance | Direction | Detect | |
|
1 |
On-Site | Yes | |
|
2 |
On-Site | Yes* | |
|
|
On-Site | Yes* | |
|
|
300 feet | South | Yes* |
|
|
700 feet | Southeast | No |
|
|
1200 feet | Southeast | No |
|
|
1500 feet | South | No |
|
|
1100 feet | West | No |
|
|
1300 feet | West | No |
|
|
1400 feet | West | No |
|
|
1100 feet | West-Southwest | No |
|
|
2700 feet | South-Southwest | No |
|
|
3200 feet | South-Southwest | No |
|
|
4700 feet | South | No |
Source - (1, Figure 8)
Other contamination detected in off-site monitoring wells is shown in Table 6 with both frequency and concentration ranges.
TABLE - 6: Organic Detects in Off-Site Monitoring Wells
| Compound | Concentration Range (ug/L) | Comparison Values |
| Acetone | 7.0 | 1,000 RMEG |
| Chlorobenzene | 4.0 | 200 RMEG |
| 1,2 Dichloroethene | 4.0-7.0 | 70 LTHA |
| Tetrahydrofuran | 1.4-1200 | None |
| Vinyl Acetate | 1.0 | 200 RMEG |
| Vinyl Chloride | 4.0-5.0 | 0.2 EMEG |
Prior to capping the site there may have been surface water runoff leaving the site during rainfall events. The intermittent drainage area to the east of the site flows beneath CTH "A" to the south. Part of the design of the cap includes a shallow surface water impoundment that catches surface water runoff from the site and prevent direct discharge from the site. This impoundment is enclosed within the site fence. The impoundment is designed to allow runoff to infiltrate to the groundwater (8). Past runoff coming in contact with exposed wastes could have been contaminated. Two surface water samples were taken from the intermittent drainage area and Sundby pond. Sample analysis did not detect contaminants. However, analysis were limited to VOCs (1, Appendix D4).
Ambient air sampling was performed as part of the remedial investigation. However, the samples were not analyzed within the necessary holding times (1, Appendix D9). The potential exists for contaminants to have migrated off-site through the air pathway during early site operation. That potential was diminished as the site was covered and became grown over with vegetation soon after disposal ceased.
Contamination Summary
Groundwater sample analysis shows contamination both on and off-site. Contaminants selected as contaminants of concern for groundwater are listed in Table 4.
Soils on-site are contaminated below the surface in the zone of waste disposal. No samples were taken of surface soils on or off-site in order to characterized past surface soil contamination. All contaminated materials on-site are now covered with clean soil and well vegetated.
Air monitoring has not characterized ambient air contamination on or off-site. Gas extraction wells have been installed at the site. Gas probes have also been installed near the site.
C. Quality Assurance and Quality Control
Analytical data obtained during the period November 1980 to October 1985 was reviewed by EPA's contractor, Roy F. Weston, Inc. to assess the usability of the data for contaminant evaluation. The data was reviewed relative to the U.S. EPA Contract Laboratory Program (CLP) procedures for validating data used for the Superfund Program and relative to procedures and reporting formats used during the period 1980-1985 (1).
The review concluded that supporting documentation for analytical data was generally not sufficient to conduct a rigorous analysis of data quality relative to current CLP requirements. However, data from commercial laboratories generally adhered to quality control (QC) requirements given in U.S. EPA methods. Analytical data from the various laboratories consistently indicated VOC contamination in on-site monitoring wells. The same data have found no contaminants in private water supply wells since July of 1983 (16, pg.4).
The review also indicated that detected values of acetone were not usable data because precautions against false detection were not in wide use at the time. THF data from samples taken in this period (1980-1985) should not be used quantitatively because this compound is not readily purged during the GC analysis method used to detect the compound. Downgradient plume characteristics were also established based on limited sampling.
In the early 1980s samples of two private wells showed detections of acetone and butyl acetate. These detections were unquantifiable at that time and the lack of certain quality control measures at the time causes those detections to be questioned.
Air samples taken during the remedial investigation were not analyzed within the necessary holding times (1, Appendix D9). These samples were not usable for site characterization.
There are no noted physical hazards associated with the site. Methane and other gasses generated from the decomposition of wastes at the site are monitored and controlled by the in-situ vapor extraction system. Because the site is completely fenced and locked, it can be assumed that on-site activities would be limited to authorized workers during cleanup related activities.
It has been alleged that in the mid 1970s underground fires broke out at the site (12). No confirming documentation can be found for these fires. THF is very flammable which could account for the underground fires alleged to have occurred at the site in the mid-1970s (18). Presently, however, all wastes are consolidated into a single disposal area. This area is capped and inaccessible to the public. It does not seem likely that either an ignition source or explosive environment exists at the site now. Contamination has been documented in the groundwater both on and off of the site boundary (1).
To determine whether nearby residents are exposed to contaminants migrating from the site, ATSDR evaluates the environment and human components that lead to human exposure. This pathways 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.
ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. Completed pathways require that the five elements exist and indicate that exposure to a contaminant has occurred in the past, is occurring, or will occur in the future. Potential pathways, however, require that at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
On-Site Groundwater
There are no exposures to groundwater contamination at the Hagen Farm site at this time. Past exposure to groundwater contamination is may have occurred at the Hagen private well.
The contaminant plume has migrated downward as it moved downgradient. Further downward migration is precluded by continuous low permeability shale layer shown in Figure 4 (1, Figure 22). Some possible explanations for this could be a combination of the following: increased degradation in the upper portion of the aquifer; dilution and displacement from infiltrating runoff downgradient; and the existence of a high permeability zone in this horizon of the bedrock (6).
There is documented groundwater contamination at and moving from the Hagen Farm site. Contaminants of concern are primarily VOCs, some of which have traveled a considerable distance from the site. Contaminants were detected in residential wells in the early 1980s. Detections of some contaminants have also been noted in the well of a private business. Since 1983 there have been no detections of contaminants in any private wells.
The well 1 was intended for watering sheep only. However, it has been alleged that the well had been used for domestic uses (13). Wells 1, 2 and 3 were located in an area now considered to be on-site because of the waste consolidation and cap construction. These three wells were each closed in the mid-1980s. The homes were removed in 1987 and the wells were properly abandoned in early summer of 1991(16). Other than well 1, the analysis from the private wells sampled did not consistently detect the above compounds. No contaminants have been detected in private wells since 1983. Table 4 shows the private wells that have been sampled and their locations in relation to the site.
Exposures to contaminated groundwater from the Hagen well may have occurred through inhalation of contaminants, ingestion of contaminants and dermal absorption of contaminants. These exposures would have begun sometime after groundwater, contaminated from wastes disposed at the site, reached these wells. Waste disposal may have begun in 1962. Because the method of disposal has not been documented, it is conservatively assumed that waste chemicals in their liquid form were dumped directly onto the ground surface and immediately moved into the groundwater. Contaminated groundwater could have traveled from the wastes to the wells soon after disposal began. Exposures could then have taken place continually until the point of exposure was removed. For the Hagen well this period cannot be determined. Mr. Hagen purchased the property in the early 70's and the well was capped in the mid-1980s. Not all contaminants are migrating from the site, the list of contaminants of concern is reduced to include those listed in Table 7. Table 7 was derived by selecting all contaminants that were listed in Table 3 that were also either detected in on-site private wells (Table 4) or detected in off-site wells above comparison values (Table 5). THF is very soluble in water. For this reason, it is quite mobile in the groundwater. While other contaminants have been detected off-site, THF has spread the greatest extent. The plume defined by Figures 1 and 2 is based on detections of THF. This plume shows an extrapolation from the sample points where THF was detected to points of non-detection. Inorganic chemicals are less mobile in the groundwater at this site than the VOCs and are not migrating from the site.
TABLE 7: CONTAMINANTS OF CONCERN
|
|
|
|
|
|
|
|
|
|
B. Potential Exposure Pathways
The likelihood of future exposures to contaminated groundwater is uncertain at this point. Although contamination has spread considerably off-site, there do not appear to be any drinking water wells screened directly in the path of the contaminant plume. If the plume continues to travel for several years without degrading or dispersing considerably other wells may become contaminated.
Off-Site Groundwater Pathway
The plume does not appear to threaten any private water supply wells with its existing course. THF was used in the process of making naugahyde and vinyl products. It is possible that THF exposure occurred at the time of transfer and disposal of the wastes. However, these potential exposures could not be separated from the exposures received at the generating facility.
Since 1983, there have been no detections of VOCs in public or private drinking water wells. Subsequent sampling has been consistent with characterization of the plume. Downgradient sampling points that have shown detects are aligned in a south-southwesterly direction from the site. Adjacent sampling points on either side do not show contamination. The general plume drawn in Figure 3 depicts a conservative estimate of plume dimensions. The points of non-detection have been used to define the edge of the plume. There are no private wells within the boundaries of this plume. In addition to the horizontal movement of the plume, contaminants are generally moving downward in the aquifer. Further downward migration of contaminants is restricted by a thin impermeable shale layer. Figure 5 represents the vertical component of the plume's migration.
Future exposures to contaminated groundwater are possible if any of the following events take place:
These scenarios are being addressed in the groundwater portion of the remediation planned for the site. Present deed restrictions preclude potable water supply wells from being placed in the area of contamination. Groundwater monitoring will be done at the site to evaluate changes in present contamination concentrations and directions of migration. Tetrahydrofuran and vinyl chloride are contaminants detected downgradient from the site in concentrations exceeding the State of Wisconsin's Groundwater Quality Enforcement Standards (17). These compounds would likely be the primary contaminants of concern for any potential future exposures to contaminated groundwater off-site.
Conservative ranges of potential future exposures may be equivalent to the highest off-site contaminant concentrations. This exposure is based on the assumption that a drinking water supply well is placed directly in the contaminant plume adjacent to the site.
Soil Exposure Pathways
Surface soil contamination has not been well documented at the Hagen Farm site. Past sampling events have not adequately characterized the existence or the extent of contaminants in surface soils for the estimation of exposures. At this point waste and contaminant sources are covered with an approved solid waste cap and, therefore, not exposed at the surface. During their disposal, wastes at the site were exposed at the surface and the potential exists for exposures to those waste contaminants to have occurred. It is not believed that there were any site access controls in place at that time.
After disposal ceased, there had been accounts of wastes at the surface. It can be assumed conservatively from this that the exposure periods began at the time of disposal and ended at the time site access was restricted in the mid-1980s.
Because the wastes in the two smaller disposal areas have been brought into the main disposal area, there are no wastes remaining outside of the access restricted area of the site. Future exposures would then be limited to breaches in the cap allowing contaminants to release to surface soils; or leachate seeps resulting in contaminated surface soils outside of the fenced area.
There is a potential that exposures to contaminated soils has occurred in the past from one or more of the following exposure scenarios:
Past potential exposure concentrations of each compound cannot be estimated from the sampling information because of a lack of data.
The site has been completely covered with a clay cap. For this reason surface soils are not contaminated and surface water runoff from the site does not come in contact with contaminants.
Air Pathway
The air pathway is no longer a potential pathway of concern, with the installation of the gas extraction system. Monitoring was attempted during the Remedial Investigation, however, usable data were not acquired. The air pathway at the site has not been well characterized. The primary contaminants of concern would have been volatile compounds because they readily release to the air. The most likely of all potential exposures to contamination from this pathway would have been during disposal and periods of exposed wastes. Exposures at that time may have included tetrahydrofuran and vinyl chloride based on waste characteristics described earlier. DNR personnel took appropriate safety precautions during the investigation of the site, as the hazards were noted by district staff early on (14).
Surface Water
Surface water does not present a viable pathway of exposure at this site. Rain water generally infiltrates directly into the unconsolidated materials on site. During high rainfall events it is possible that some surface water could have left the site with contaminants during periods of exposed wastes. Existing runoff controls preclude future migration of contaminants via surface water. Limited sample analysis of surface water did not detect volatile contaminants. There is a potential that metals from the site may exist in sediments in the drainage area because of their persistence in the environment. However, the porous site soils make run off from the site unlikely.
The following section consists of summaries of the toxicological implications for each contaminant of concern for completed or potential exposure pathways. The contaminants of concern were selected based on their exceedance of comparison values, or when no comparison value is available.
Butyl Acetate
Levels of butyl acetate detected in on-site private wells were below the quantifiable detection limits of 3 �g/L. No other groundwater samples have shown detections of this compound. There are no possible health effects associated with exposure to these levels of butyl acetate (19).
1,2 Dichloroethylene
There has not been documentation of an exposure to 1,2 dichloroethylene at the Hagen Farm Site. Well 1 had a concentration of 1,2-dichloroethylene at 400 �g/L. Very little is known about this compound. No cancer data is available to classify it as a carcinogen. No health effects have been associated with exposure to 400 �g/L of this compound (20).
Tetrahydrofuran (THF)
The on-site livestock well had THF at a concentration of 2200 �g/L. THF is the primary contaminant of concern at this site because of both the concentration and the extent of contamination.
THF is a volatile organic compound (VOC) that readily releases to the air pathway. This compound has been found consistency in the highest concentrations in the groundwater (18).
Very little toxicological data is available for THF. Short term exposures to the highest levels of THF on-site through inhalation could irritate the eyes, nose, throat and lungs. Long term exposures may effect liver or kidney function. Limited testing has been done on animals to evaluate THF as a carcinogen. THF has not been evaluated for its ability to cause cancer humans(19, 21, 24).
Vinyl Chloride
Vinyl chloride was detected at 102 �g/L in the on-site livestock well. As with the THF discussion above, the plume does not appear to threaten any private water supply wells with its existing course.
Vinyl chloride is classified by the U.S. EPA as a known human carcinogen. Exposure to the contaminated drinking water from the site could result in a low increased risk of developing cancer (7, 19).
B. Health Outcome Data Evaluation
A review of health outcome data is appropriate when there is evidence of people who have been exposed to contaminants at levels which could lead to an increase in rates of death or illness. "Health Outcome Data" refers to records of death and/or disease. A review of health outcome data might also be appropriate if there are reports of unusual clusters or higher-than-expected levels of specific diseases near a site.
Based on existing data from the RI and current research on diseases caused by contaminants which were found at the site, the levels of exposure to contaminants are too low to initiate any studies of death and illness. Attempts to locate Mr. Hagen have been unsuccessful. The only person allegedly living on-site for a short period died from non-site related causes.
C. Community Health Concerns Evaluation
The following are responses to concerns expressed by residents living near the site.
With the addition of an impermeable cover on the landfill, the surface water runoff will be increased. Runoff controls have been included in the design of the new cover. It is expected that these controls will alleviate any increased erosion potential. Because of the high infiltration rate in area soils, including soil down gradient, it is expected that the water levels will quickly return to their natural states.
The contaminant plume is travelling generally in a southwesterly direction from the site. The plume itself is quite narrow and presently isn't impacting any private water supply. Assuming the same general flow patterns and flow rates, it does not appear that the plume would reach private wells within the next few years. This also assumes that no groundwater remedial action takes place. Remedial design for existing groundwater contamination is underway and is expected to capture the present plume. The groundwater remediation process will serve to reduce existing contamination to acceptable levels.
At present, all wells believed to be within the area of potential impact from the contaminant plume are being sampled regularly. If other wells are not being sampled, those wells are considered to be free from site related contamination. Monitoring wells were installed both on and off site such that the edge of the contaminated area would be defined. Wells outside of this area are not detecting contamination and are being monitored for change.
If, however, there is concern that a well is contaminated and has not been sampled the DNR water supply specialist in the district office should be contacted. Solvent, plastic resin or other odors in the water would be an indicator that contamination may be present.
It is not expected that contamination will spread to existing water supply wells. However, should the plume direction change, the remedial action would be modified to address any additional contamination. Regular sampling would identify these changes and, if necessary, arrangements could be made for an alternative drinking water supply. These arrangements would be made by the responsible parties, and would be overseen by the DNR.
Yes. If water contaminated, above specific levels, with the compounds of concern was fed to livestock, the product of the livestock may be deemed unfit for sale. This could affect milk grade rating as well. It is not believed, however that there are any contaminated water supply wells presently serving livestock.
Development anywhere within 1200 feet of the site cannot include the installation of water supply wells without a variance from the WDNR. Such a variance would consider factors such as location of contamination and direction of plume movement. This is a requirement that applies to all active and abandoned landfills in the state of Wisconsin. This makes it unlikely that any new homes will be developed in areas of potential contamination unless a municipal water supply is extended to them. Existing wells are exempt from this requirement.
The value of protecting human health has not been established at this site or any other site of its kind. However, the cost of the cleanup at this site is in line with the related costs of similar sites around the state and across the country.
The State cannot give an enforceable guarantee of this nature at any site in the state. The present restrictions on well placement in the immediate vicinity and the continued investigations being done should ensure that future public heath is also protected.
There does not appear to have been substantial exposures to contaminants at this site. Based on the information available and the potential for exposure, the DOH does not believe past illness or death in the area can be related to contaminants from the site.
The site presents no public health hazard because there is no current exposure and the two residents who experienced past exposures no longer live on the site, therefore, an assessment of their health impacts is not possible. A public health hazard would exist if contaminated groundwater migrates to private drinking water wells in the future or if releases to the air pathway occur and are not mitigated. Planned remedial activities are expected to adequately address these potential exposures.
Volatile organic compounds are the only contaminants migrating significantly from the site. Contamination is not migrating from the site by any other route than groundwater. Groundwater contamination has spread significantly from the site. Groundwater is contaminated, however there are presently no impacted water supply wells affected.
Site access is sufficiently restricted and wastes are not exposed to the surface. There is a lack of soil and air quality data. For this reason, it is not possible to fully evaluate exposures to these pathways. Significant exposures by these routes in the past are not believed to have occurred. Potential for future exposures by these routes has been removed by the construction of a cap on the site.
The Wisconsin Division of Health offers the following recommendations concerning the Hagen Farms site:
Need For Follow-up Health Activities
The ATSDR Health Activities Recommendation Panel (HARP) and the Wisconsin Division of Health evaluated the data on this site to determine what needs exist for additional research and/or local education about health related concerns. Such activities could include further studies on cases of disease in the vicinity of the site or providing residents with additional information about the health effects of exposures to specific toxic chemicals coming from the site. One individual may have been exposed to contaminants in groundwater. This person no longer lives near the site and attempts to locate the man have failed. No other persons are believed to have been exposed to contaminants from the site. Therefore, no studies of the site's impact on public health are needed at this time. WDOH and ATSDR will evaluate the need for more health activities if new information reveals that public exposure to contamination from the site has occurred. In addition, WDOH will continue to work with local residents and area health professionals to address community health concerns.
Public Health Action
The recommendations provided in the Health Assessment are related to the prevention and monitoring of possible human exposure to contaminants from Hagen farms site. The following actions either have been or will be performed to meet the needs expressed by the recommendations of this Health Assessment. The DOH, in cooperation with ATSDR, will conduct the following activities to respond to the recommendations of this assessment:
Chuck J. Warzecha
Hydrogeologist
Section of Chronic Disease & Health Assessment
Bureau of Public Health
Division of Health
Wisconsin Department of Health & Social Services
ATSDR Regional Representative
Louise Fabinski and Manna Edwards
Regional Services
Region V
Office of the Assistant Administrator
ATSDR Technical Project Officer
William J. Greim
Environmental Health Scientist
Division of Health Assessment and Consultation
Remedial Programs Branch
The Hagen Farm Public Health Assessment was prepared by the Wisconsin Department of Health and Social Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
William Greim
Technical Project Officer, SPS, RPB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment, and concurs with its findings.
Director, DHAC, ATSDR
Comments are presented in regular type, while the responses to those comments follow in bold type.
| Preface | The preface should explicitly state that this document is the full health assessment, not a continuation of the preliminary health assessment. The Preface is not explicitly in this regard. |
This has been clarified in the preface.
| Summary | The comment recommends that paragraph 3 of the summary should be phrased as "...two residents who experience past exposures no longer live on the site", to more accurately convey the situation to the reader. |
The wording has been changed.
| Background/3 | "galuconitic" should be "glauconitic" |
The misspelling has been corrected.
| Background/4 | The site description is out of date. The three disposal areas have been consolidated and covered. Trees have been removed and replaced with a grass. In the fourth and fifth sentences of the second paragraph, the verbs should be past tense (encompasses should be encompassed and consists should be consisted). |
The wording has been changed.
| Background/6 | The second and third sentences of the fifth paragraph on this page should be reworded as follows: "A portion of the source control remedial action is already in place at the site. The source control activities already accomplished are the consolidation of the wastes, the capping of the consolidated wastes, and the security fencing of the capped and consolidated waste area." |
The wording has been rephrased to reflect this information.
| Site Visit/6 | The first and second sentences of this section should be reworded as follows: The first site visit by the DOH was conducted on May 25, 1988. At that time, the gate to the site was open, and ..." |
The wording has been changed.
| Site Visit/7 | Since the site visit, the landfill cover and other areas of bare soil have been fully vegetated. A six-foot high security fence topped with three stands of barbed wire and posted with warning signs has also been installed around the capped landfill. |
The following changes and additions should be made to the third sentence in the last paragraph of this section: "In the spring of 1992, three in-situ vapor extraction (ISVE) wells were installed in order to conduct a pilot study to define and optimize the operating parameters for the full-scale ISVE system. The pilot study was completed in August 1992. The results of this study were used to complete the design of the full-scale ISVE system, including the replacement of one of the gas extraction wells and addition of five more gas extraction wells, will be constructed in the autumn of 1993. Also, a total of eight existing and 21 additional gas probes will be installed to monitor any gas migration that may occur in and around the landfill."
This information has now been added to the previous section. The site visit section is intended to only reflect observations and conditions as they were during the visit.
| Community Health Concerns/9 | The assessment would be more complete if the dates and methods of contact with residents were specified. |
This information is not available.
| Soils/11 | In the first paragraph, sentence eight should be changed as follows: "Wastes believed to have been disposed were municipal wastes, solvents, other organic materials, and vinyl." |
The wording has been changed.
In the second paragraph, it would be appropriate to note that, "Hagen Farm is a relatively small landfill (<5 acres) which accepted limited amounts of municipal solid wastes during its short operating life (c. 1962 to 1966). These factors combine to reduce the likelihood of significant methane gas production at the site."
This has been added later in this section.
The following changes and additions should be made to the fifth, sixth, seventh, and eighth sentences of the second paragraph: "Therefore, there is only a small potential for gas migration from the site to the air pathway. Gas extraction wells were installed in the spring of 1992 for the ISVE pilot study. Among the goals of that study was to access the volume of gas production in the landfill and to assess the volume and distribution of gaseous VOC contaminants beneath the cap. Methane gas production is common at landfills containing municipal wastes, however, the volume of municipal wastes disposed at this site was very limited and the ISVE system to be installed at the site will eliminate the possibility of gas migration from the landfill. Other contaminants present in the landfill may volatilize and could then migrate along with any methane gas that is generated"
This information was added to the pathways analysis section of the document.
Further, paragraph 2 should note that all disposal areas are now covered and vegetated and the site is secure.
This information was added.
| Groundwater/12 | Table 1 would be more readily understood if a glossary were provided for the acronyms in the "Comparison Values" column, such as RFD. |
Definitions have been added.
| Groundwater/13 | Table 2 would be consistent with Table 1 (and more informative) if a range of values for contaminant concentration were shown. |
Because many of the inorganic compounds are naturally occurring, only the highest levels were listed.
| Private Wells/13 | This paragraph would be more accurate with the addition of the following: Wells 1,2, & 3 are now abandoned and plugged. Well #4 is owned by a sand and gravel company and is used as a process water source for the business, not as a potable drinking water source." |
The wording has been revised.
| Private Wells/14 | Table 4 and Table 7 are labeled "Contaminants of Concern". The comment recommends that Table 7 and related text be edited to read "Assessment Contaminants" or some such unique phrase. |
The wording in the table heading has been revised to reflect contaminants of concern for this health assessment. We are not discussing contaminants of concern as defined by a remedial investigation.
| Private Wells/14 | The comment suggests that the last sentence is an inaccurate characterization of downgradient contamination. Downgradient contamination is relatively small with the exception of elevated THF values. The comment suggests this sentence be rewritten as follows: "Relatively large concentrations of THF have been detected in groundwater downgradient of the site. Concentrations of THF have been detected in groundwater downgradient of the site. Concentrations of TFH range from 1.4 to 1200 ug/liter (parts per billion). Other VOC's are also detected at relatively small concentrations (less that 10 part per billion)". |
The wording has been clarified to focus on THF, though the emphasis on the size of the plume remains.
| Off-Site Contamination/14 | The first paragraph should be expanded to explain that contaminants are sinking in the aquifer presumably because of a combination of the following: increased degradation in the upper portion of the aquifer, dilution and displacement from infiltrating runoff downgradient, and the existence of a high permeability zone in the upper horizon of the bedrock. |
Additional information has been added.
| Off-Site Contamination/15 | In Table 5, the asterisks in the "Detect" column need to be explained. |
An explanation has been added.
| Off-Site Contamination/16 | In the third sentence of the first paragraph following Table 6, the verb should be present tense instead of future tense ("that will catch" should be "that catches") because the impoundment has already been constructed. |
This change has been made.
| Contamination Summary/16 | The last paragraph on 16, the second sentence should be changed to read as follows: "The three gas extraction wells that have already been installed at the site, were installed through the newly-constructed landfill cap. |
This information has been updated.
| Physical & Other Hazards/17 | The first paragraph inaccurately characterizes the hazards posed by gases generated at the site. There are no structures present which could accumulate gas. The comment suggests that the first paragraph be rewritten as follows: "There are no noted physical hazards associated with the site. Methane and other gases generated from the decomposition of wastes at the site could pose a fire and explosion hazard; however, no on-site structures are present where gases can accumulate in explosive quantities. Further, an In-Situ Vapor Extraction System has been tested at the site, and a full-scale system has been designed to extract and treat gases. No off-site migration of site gases has been detected. Because the site ...." |
This section has been updated.
| Completed Exposure Pathway/19 | The first paragraph in the "groundwater" section could be more accurately written as "Past exposure to groundwater contamination may have occurred at the Hagen private well." This rephrasing is consistent with the discussion page 20. |
The wording has been changed.
In the third paragraph, VOC's are said to be 3,200 feet downgradient. On page 14, the plume is said to be 1,500 feet downgradient. The actual farthest point at which VOC's have been detected is approximately 2,000 feet downgradient of the capped and consolidated landfill area.
The furthest downgradient point of contamination is not defined in the RI. It is agreed that 3,200 feet is conservative. The number on page 14 has been changed to 2,000 feet.
Also a sentence should be added to the third paragraph stating: "The contaminants detected in wells, 2,3, and 4 are suspect because of the lack of quality control measure taken at the time of the sample analysis".
This information is stated earlier in the document. Additions have been made based on previous comments.
In the sixth sentence of the fourth paragraph, the word "Detected" should instead be "detect".
This misspelling has been corrected.
| Potential/exposure Pathway/21 | The first paragraph should be clarified as follows: "...there do not appear to be any drinking water wells screened directly..." |
This correction has been made.
Potential Exposure Pathway-Groundwater/21
Typographical error: The two words "nauga hyde" in the second sentence of the first paragraph should be one word (Naugahyde).
The typo has been corrected.
In discussing future exposures, it would be appropriate to add, "The likelihood of a break in the cap or any leachate seeps is substantially diminished by the nature of the materials chosen to construct the cap and the obligation for the site owner to routinely inspect the site to detect such occurrences."
A likelihood of these occurrences is not alluded to in the text. There is no need to add this discussion.
The following sentence should be added after the forth sentence: "The full-scale ISVE system, when installed, will eliminate the possible migration of these volatile compounds."
This section has been updated to reflect the addition of the ISVE.
| Public Health Implication/24 | This section would be easier to understand if an explanation were repeated about how the four "Assessment Contaminants" were selected. |
A brief statement has been added.
| Tetrahydrofuran (THF)/24 | The statement in the last sentence of the last paragraph of this section is erroneous. THF has been tested for its ability to cause cancer. In fact, the National toxicology Program (NTP) completed a two-year carcinogenicity bioassay of THF in rats and mice exposed via inhalation in December 1991. Currently, the tissues from exposed and control animals are undergoing histopathological examination. The NTP assessment of THF's potential carcinogenicity should be available within the next 18-24 months. |
The text has been clarified to acknowledge this test. However, animal testing for THF's carcinogenicity has not been consistent. Some studies has shown it to enhance tumor growth, mutagenicity, and embryotoxicity in mice. Still other studies have not found these effects. For this site, should an exposure to THF occur in the future, the specific exposure would be again evaluated for potential health effects.
| Community Health/26 | The answer to question #3 may be more informative if residents were alerted to be aware for "solvent, plastic resin, or other odors." |
This text has been added.
| Community Health/27 | There is nothing in question #8 about changes in property values. The comment requests that the last sentence in the answer to question #8 be deleted. |
This sentence has been removed.
| Community Health/27 | The answer to question #9 uses the first person ("I"). This should be rephrased to read "the DOH does not believe in "or" it is not believed that ...." |
This has been changed.
| Conclusions/28 | The first sentence should be rephrased to read " ....two residents who experienced past exposure no longer live at the site." |
The text has been changed.
| Conclusion/28 | The second paragraph should be clarified as follows: "Groundwater contamination especially THF) has spread significantly from the site in a narrow, well defined plume. Groundwater is contaminated: however, there are presently no water supply wells affected." |
The text was not modified. This information is noted earlier and not necessary here.
| Recommendations/29 | General Statement: WMWI supports the Public Health Action (stated on page 3) which WDOH and ATSDR will conduct. WMWI will cooperate fully with WDOH and ATSDR in this regard, and suggests that the RECOMMENDATIONS in this assessment be tailored to those public health actions. The remedial measures selected by U.S. EPA for the two operable units at the Hagen Farm site are, by law, protective of public health and the environment, and no additional testing, design, or construction is necessary. |
The DOH notes and appreciates WMWI's support. The recommendations have been updated to reflect more recent information.
Paragraph I - Rephrase to endorse continued monitoring.
The DOH has not received information from the new monitoring wells to indicate that the plume has been well characterized. Until that time the DOH maintains this recommendation.
Paragraph 2 - Delete
This recommendation remains in place.
Paragraph 3 - Inform residents of groundwater testing results. No additional private well testing is needed.
The wording has been changed to monitoring wells and selected private wells as appropriate. This reflects the potential need for private well sampling when the plume is not confidently characterized and contained with in the monitoring well coverage.
Also, how will 1,200 feet from the site be defined? Will it be defined as from the property line, or from the capped waste consolidation area or from some other point? who will be apprising the residents of this information? Will the U.S. EPA and the WDNR, or some other entity do this appraisal.
The wording has been changed to "near" the site. Residences within the area of past private well monitoring are expected to be included.
Paragraph 4 - The second sentence of this paragraph should read as follows: "The annual site inspection that is currently performed each spring at the site includes the inspection of the cap and the surface water runoff controls to ensure their effectiveness."
This paragraph has been removed.
Paragraph 5 is O.K.
Paragraph 6 - Delete
The paragraph has been rephrased to state "If additional information becomes available on past or current exposures, the DOH will evaluate those exposures for potential health risks."
| References/31 | "Morozoite" is "Morrisette" - References 5 and 13. |
The misspelling has been corrected.
"Jay" is "Jae" - Reference 6
The misspelling has been corrected.
"Rod" is "ROD" - Reference 10
The typo has been corrected.
