RIPON CITY LANDFILL
RIPON, FOND DU LAC COUNTY, WISCONSIN
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
This section describes contamination and other hazards associated with the Ripon FF/NN Landfill Superfund site. Contaminants of concern are selected for further analysis in following sections.
Contaminants of concern are those contaminants migrating from the landfill that have the potential to affect human health. Isolating these contaminants from the long list of those that may be found at a site allows the assessor to focus on fewer, more important, contaminants. Sample results from the remedial investigation are used to evaluate all environmental pathways with potential human exposure routes. Human exposure routes are points where contaminants may enter the body and include: inhalation, ingestion, and dermal absorption. The environmental pathways evaluated include: groundwater, surface water, surface soils, and air.
"Comparison values" are used to help select potential contaminants of concern from the results of samples taken at the site. A comparison value is a contaminant concentration level below which human exposure is likely to be without harmful health effects. Comparison values are derived from toxicity data and exposure dose assumptions for specific media (e.g. soils, drinking water, etc.). Sample results summary tables in this section include comparison values for the respective contaminants detected in each media evaluated. Concentrations at or above these levels do not necessarily represent a health threat. All other areas are considered to be "off-site". On-site contamination has been detected in groundwater and leachate seeps coming from the landfill. Off-site contamination has been detected in groundwater.
ON-SITE CONTAMINATION
The landfill contains an estimated 6 to 11 million gallons of leachate(6). Samples were taken of the landfill leachate to determine which contaminants could possibly be migrating from the landfill. The contaminants detected are shown in Table 1. Of the parameters detected the VOCs are the most mobile in the groundwater, followed by the metals and the semivolatile organic compounds (SVOCs).
Table 1(7)
Contaminants Detected in Landfill Leachate
| VOCs | SVOCs | Metals |
| Vinyl chloride | Phenol | Arsenic |
| Chloroethane | 2-Methyl phenol | Barium |
| Cis 1,2 dichloroethylene | 4-Methyl phenol | Cadmium |
| Trichloroethylene | 2,4 Dimethyl phenol | Chromium |
| Benzene | Naphthalene | Iron |
| Toluene | 4-Choro 3-methyl phenol | Lead |
| Chlorobenzene | 2-Methylnaphthalene | Manganese |
| Ethyl benzene | Dimethylphthalate | Selenium |
| Xylenes (total) | Diethylphthalate | Silver |
| 1,4 Dichlorobenzene | Pentachlorophenol | Zinc |
| Butylbenzylphthalate |
As part of on-going investigations at the site, nineteen monitoring wells were installed during the summer and fall of 1993. Groundwater contamination has been detected in monitoring wells adjacent to the site and to the south and west of the site. The monitoring wells to the north and the east have not shown contamination. VOC contaminants detected in groundwater monitoring wells are shown in Table 2 at their highest detected levels. VOC concentrations meeting or exceeding their comparison values are shown in bold type. These compounds are contaminants of concern for on-site groundwater. 1,4 Dichlorobenzene is considered to be a possible carcinogen. For this reason it is selected as a contaminant of concern even though its concentration is below the comparison value. Two metals also detected at concentrations exceeding their comparison values are also contaminants of concern. Those metals are shown at their highest concentrations in Table 2.
Table 2(8)
Contaminants in On-Site Groundwater
(Contaminants of Concern in Bold)
| VOC | Maximum Detected Concentration (ppb) | Comparison Value (ppb) |
| Benzene | 2.0 | 1.0c |
| Chlorobenzene | 2.0 | 200r |
| 1,4 Dichlorobenzene |
2.0 |
75l |
| Cis 1,2 dichloroethylene | 410 | 70l |
| Tetrachloroethylene | 0.7 | 0.7c |
| Trichloroethylene | 2.0 | 3.0c |
| Vinyl chloride | 75 | 0.2e |
| Metals | ||
| Arsenic | 21.6 | 0.02c |
| Manganese | 2150 | 50r |
| c - CREG, Cancer Risk Evaluation Guide for 1x10-6 excess cancer risk
r - RMEG, Evaluation guide derived from EPA's Reference Dose l - LTHA, Lifetime Health Advisory for Drinking Water e - EMEG, Environmental Media Evaluation Guide |
Leachate seeps at the eastern side of the landfill represent additional on-site contamination. The seeps were sampled in October, 1991. The results are summarized in Table 3. Drinking water comparison values are also included in the table. The use of the drinking water comparison values for this purpose is extremely conservative. These values assume that people would be drinking two liters of leachate from the seeps each day over the course of a lifetime. None of the contaminants were detected at concentrations exceeding the comparison values where available. Only the two trimethyl benzenes are selected as contaminants of concern because no comparison values are available for them.
Table 3
On-Site Leachate Sample Results
| Contaminant | Detected Concentration (ppb) |
Comparison Value (ppb) |
| VOC | ||
| Chlorobenzene | 5.0 | 200r |
| Ethyl benzene | 66 | 700l |
| Naphthalene | 30 | 20l |
| 1,2,4 Trimethyl benzene | 15 | NA |
| 1,3,5 Trimethyl benzene | 5.0 | NA |
| Xylenes (total) | 63 | 2000e |
| SVOCs | ||
| Di-n-Butylphthalate | 15 | 1000r |
| Metals | ||
| Barium | 233 | 700r |
| Lead | 2.0 | 15m |
| Manganese | 250 | 50r |
| r - RMEG, Evaluation guide derived from EPA's Reference Dose
l - LTHA, Lifetime Health Advisory for Drinking Water e - EMEG, Environmental Media Evaluation Guide m - MCL, EPA Maximum Contaminant Level |
OFF-SITE CONTAMINATION
In November 1984 water samples from a private well approximately 500 feet south of the landfill contained vinyl chloride. A sample taken from that same well earlier that year did not contain contamination. In June of 1989, that private well was replaced with a deeper well. The new well was also found to contain vinyl chloride, trichloroethylene, and 1,2 dichloroethylene. Table 4 shows the contaminants detected at this home at their highest concentrations. Because vinyl chloride exceeds its comparison value it is shown in bold type and is retained as a contaminant of concern for off-site groundwater. Table 5 is a summary of off-site monitoring well sample results from the remedial investigation. Again only vinyl chloride is considered a contaminant of concern for off-site groundwater. During the remedial investigation in 1993, 23 private wells were sampled within a half mile of the site. None of the samples from these wells detected contaminants related to the site.
Table 4(9),(10)
Residential Well Contamination
| VOC | Maximum Detected Concentration (ppb) | Comparison Value (ppb) |
| 1,2 Dichloroethylene | 18 | 70l |
| Trichloroethylene | 1.8 | 3.0c |
| Vinyl chloride | 47 | 0.2e |
| c - CREG, Cancer Risk Evaluation Guide for 1x10-6 excess cancer risk
l - LTHA, Lifetime Health Advisory for Drinking Water e - EMEG, Environmental Media Evaluation Guide |
Table 5(11)
Off-Site Monitoring Well Sample Results
| VOC | Maximum Detected Concentration (ppb) |
Comparison Value (ppb) |
| 1,2 Dichloroethylene | 4.0 | 70l |
| Toluene | 11 | 1000l |
| Trichloroethylene | 2.0 | 3.0c |
| Vinyl chloride | 6.0 | 0.2e |
| c - CREG, Cancer Risk Evaluation Guide for 1x10-6 excess cancer risk
l - LTHA, Lifetime Health Advisory for Drinking Water e - EMEG, Environmental Media Evaluation Guide |
The WDOH conducted indoor air sampling at the home with the contaminated private well in September of 1989. There were four samples taken. One sample was taken in the basement while clothes were being washed. One was taken in a doorway between the living room and kitchen. Two were taken in the first floor bathroom, one of which was taken while the shower was running. Table 6 shows the results of those samples analyzed for vinyl chloride.
Table 6(12)
Results of Indoor Air Samples
| Sample Location | Vinyl Chloride Concentration (ppm) |
| Kitchen | Not Detected |
| Basement | 0.01 |
| Bathroom | 0.03 |
| Bathroom w/Shower | 0.06 |
The home is no longer occupied and both private wells on the property have been abandoned.
In June 1986, subsurface samples from beneath the wetlands northeast and southwest of the site detected VOCs. These samples were taken from excavations dug two to three feet below ground surface in the wetlands. Samples taken in the wetlands during the remedial investigation did not contain contamination, indicating that contamination is not discharging into the wetlands in measurable amounts.
QUALITY ASSURANCE AND QUALITY CONTROL
In preparing this assessment, the WDOH relies on the information provided in the referenced documents and assumes that quality assurance and quality control measures were followed concerning chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn for this assessment is determined by the reliability of the referenced information.
TRI SEARCH
The Toxic Chemical Release Inventory (TRI) was searched for chemical releases from the Ripon FF/NN Landfill site and other facilities in the same zip code area. The landfill site was not listed in the TRI. No other releases were reported in the vicinity of the site.
PHYSICAL AND OTHER HAZARDS
There is no site access restriction to prevent people from walking across the site. There are no physical hazards related to fire and explosion from the site, as it is not producing sufficient quantities of methane gas. Site slope and miscellaneous debris may present a slip/trip/fall type hazard.
PATHWAYS ANALYSES
This section describes exposure scenarios for known (completed) exposures and for exposures that may have occurred or could occur in the future (potential). These exposures are considered along with the toxicological information for the respective contaminants of concern to determine likely health effects from the exposures.
COMPLETED EXPOSURE PATHWAYS
There has been one documented completed exposure to contaminants from the Ripon FF/NN Landfill. VOC contamination in groundwater migrated south to a private residential water supply approximately 500 feet from the site. The water supply was tested in 1984 and found to be contaminated with vinyl chloride. The residents were advised by the WDNR and WDOH that the water should not be used for any purpose. They were also advised of the health risks associated with using the water. In 1990 the WDNR abandoned the existing water supply well to prevent further use of the water supply. The residents using contaminated groundwater from that well ingested contaminants when drinking water, and inhaled contamination released from the water during domestic uses (cooking, showering, etc.). The water supply may have been contaminated a few years after waste disposal began. Because vinyl chloride is the only contaminant of concern for this pathway. A conservative estimate of exposure would assume the exposure began in 1984 when the contamination reached the residential well and ended when the well was abandoned in 1990 (six years). It is also assumed that the vinyl chloride concentration in that well was at its highest detected level (47 µg/L) for that seven year period. These assumptions lead to an exposure of approximately 4.7 µg/Kg/Day for a 10 Kg child drinking one liter of water each day, and 1.3 µg/Kg/Day for a 70 Kg adult drinking two liters of water each day.
No other completed exposure pathways exist at the site.
POTENTIAL EXPOSURE PATHWAYS
Residents living near the site rely on groundwater for their drinking water and other domestic uses. There is currently no exposure to contaminants from the site. There is a very low potential that contamination from the site could migrate to additional private wells. The nearest down gradient private wells are approximately 2000 feet from the site. The wetland to the southwest of the site lies between the site and those private wells, making it more unlikely for them to be at risk of contamination from the site. If a private well were to become contaminated the residents using the contaminated groundwater from that well could ingest contaminants when drinking water; inhale contamination released from the water during domestic uses (cooking, showering, etc.); and absorb contaminants through their skin while bathing and washing in contaminated water.
Vinyl chloride is the only groundwater contaminant of concern at this site that could migrate from the site at levels of health concern. For this reason no other groundwater contaminants of concern identified in Table 2 are considered for potential exposure pathways.
Another potential exposure could be caused by the existence of leachate seeps on the eastern slope of the landfill cap. Contamination has been documented through sampling in that area. Exposures to this leachate could result from direct skin contact with the leachate while walking across this portion of the site. Unsupervised children playing on-site could also ingest the leachate or leachate contaminated soils from this area. Interviews with nearby residents indicated that parents do not allow their children to enter the site. A general discussion of health effects related to exposure to these seeps is included in the next section.
PUBLIC HEALTH IMPLICATIONS
This section provides a discussion of possible health effects that could be related to completed or potential exposures to contaminants identified in the Environmental Contamination Section.
TOXICOLOGICAL EVALUATION
Residential Well
Vinyl Chloride
The completed exposure to vinyl chloride described in the previous section poses an increased
cancer risk to the residents who used the water for drinking and other domestic uses. Sampling
confirmed that there was exposure through ingestion as well as through inhalation during other
potable uses. Vinyl chloride is a very potent human carcinogen. Low levels of exposure over an
extended period of time is expected to significantly increase a person's risk of getting cancer.
Studies with laboratory animals also suggest that long term exposures to high levels of vinyl
chloride may cause changes in the liver(13).
Leachate Seeps
Trimethyl Benzenes
There is little toxicological information available for the trimethyl benzenes detected. However,
the information available indicates that exposures to the concentrations in the leachate seeps is
not expected to cause adverse health effects(14).
Naphthalenes
No adverse health effects are associated with exposure to naphthalene at the concentrations found
in the leachate. Such an exposure would have to include ingestion of nearly two liters of the
landfill leachate each day over the course of a lifetime before being considered a health concern.
Manganese
No adverse health effects are associated with exposure to manganese at the concentrations found
in the leachate. Such an exposure would have to include ingestion of nearly one half a liter of the
landfill leachate each day over the course of a lifetime before being considered a health concern.
Other Possible Contaminants
The leachate in the landfill contained several organic compounds and metals that are considered
to be carcinogens. Most of these contaminants have not been detected during leachate sampling.
However, there is a potential that they may also migrate from the landfill in the seeps. The
concentrations of these compounds is not high enough in most cases to cause acute health effects.
Some acute effects that could be caused by prolonged contact or long term inhalation of
chemicals from the leachate are: skin irritation from the organic solvents in the leachate and
possibly the chromium at higher concentrations; respiratory irritation from inhalation of the
VOCs and SVOCs(15),(16),(17),(18),(19). Such exposures have not existed in the past at the site and do
not currently exist, as has been mentioned earlier in this document.
HEALTH OUTCOME DATA EVALUATION
"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 community health concerns related to the site have been reported. No health outcome data review is warranted as a result of this evaluation. There is an indication of exposure to vinyl chloride that could pose an increased cancer risk. However, the exposure occurred at only one residence. A health outcome data review would not be appropriate for this site. Should additional information of human exposures be found, a review of health outcome data will be reconsidered.
COMMUNITY HEALTH CONCERNS EVALUATION
This section addresses the community health concerns identified earlier in the document. community health concerns were solicited at a public meeting held in April of 1993 in the City of Ripon. Chuck Warzecha and Mary Young also interviewed the residents living near the site in the summer of 1993. In general the residents were well informed about the site and were not concerned that the site could affect their health.
WDOH is recommending to the WDNR that a monitoring plan be established that would warn of the migration of groundwater contamination that could threaten private wells. Current information about the site indicates that existing private wells are not likely to be threatened by groundwater contamination from the site.
The pipes are passive gas vents that allow landfill gasses to leave the landfill as they are generated. These vents have been monitored and indicate that the landfill is not producing much landfill gas. These vents are not expected to pose a health hazard to nearby residents.
In response to the concerns raised by these residents, the WDNR sampled some of the wells with water quality problems. The sample results indicate that each well has an iron bacteria problem. The iron bacteria problem has no relationship to the landfill site. The WDNR is working with the private well owners to identify a solution for the iron bacteria problem.
