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This section describes contamination and other hazards associated with the Ripon FF/NNLandfill Superfund site. Contaminants of concern are selected for further analysis in followingsections.

Contaminants of concern are those contaminants migrating from the landfill that have thepotential to affect human health. Isolating these contaminants from the long list of those thatmay 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 pathwayswith potential human exposure routes. Human exposure routes are points where contaminantsmay enter the body and include: inhalation, ingestion, and dermal absorption. Theenvironmental pathways evaluated include: groundwater, surface water, surface soils, and air.

"Comparison values" are used to help select potential contaminants of concern from the results ofsamples taken at the site. A comparison value is a contaminant concentration level below whichhuman exposure is likely to be without harmful health effects. Comparison values are derivedfrom 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 respectivecontaminants detected in each media evaluated. Concentrations at or above these levels do notnecessarily represent a health threat. All other areas are considered to be "off-site". On-sitecontamination has been detected in groundwater and leachate seeps coming from the landfill. Off-site contamination has been detected in groundwater.


The landfill contains an estimated 6 to 11 million gallons of leachate(6). Samples were taken ofthe landfill leachate to determine which contaminants could possibly be migrating from thelandfill. The contaminants detected are shown in Table 1. Of the parameters detected the VOCsare the most mobile in the groundwater, followed by the metals and the semivolatile organiccompounds (SVOCs).

Table 1.

(7) Contaminants Detected in Landfill Leachate
Vinyl chloridePhenolArsenic
Chloroethane2-Methyl phenolBarium
Cis 1,2 dichloroethylene4-Methyl phenolCadmium
Trichloroethylene2,4 Dimethyl phenolChromium
Toluene4-Choro 3-methyl phenolLead
Ethyl benzeneDimethylphthalateSelenium
Xylenes (total)DiethylphthalateSilver
1,4 DichlorobenzenePentachlorophenolZinc

As part of on-going investigations at the site, nineteen monitoring wells were installed during thesummer and fall of 1993. Groundwater contamination has been detected in monitoring wellsadjacent to the site and to the south and west of the site. The monitoring wells to the north andthe east have not shown contamination. VOC contaminants detected in groundwater monitoringwells are shown in Table 2 at their highest detected levels. VOC concentrations meeting orexceeding their comparison values are shown in bold type. These compounds are contaminantsof concern for on-site groundwater. 1,4 Dichlorobenzene is considered to be a possiblecarcinogen. For this reason it is selected as a contaminant of concern even though itsconcentration is below the comparison value. Two metals also detected at concentrationsexceeding their comparison values are also contaminants of concern. Those metals are shown attheir highest concentrations in Table 2.

Table 2.

(8)Contaminants in On-Site Groundwater (Contaminants of Concern in Bold)
VOCMaximum Detected Concentration (ppb)Comparison
Value (ppb)
1,4 Dichlorobenzene



Cis 1,2 dichloroethylene41070l
Vinyl chloride750.2e
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. Theseeps were sampled in October, 1991. The results are summarized in Table 3. Drinking watercomparison values are also included in the table. The use of the drinking water comparisonvalues for this purpose is extremely conservative. These values assume that people would bedrinking two liters of leachate from the seeps each day over the course of a lifetime. None of thecontaminants were detected at concentrations exceeding the comparison values where available. Only the two trimethyl benzenes are selected as contaminants of concern because no comparisonvalues are available for them.

Table 3.

On-Site Leachate Sample Results
Concentration (ppb)
Value (ppb)
Ethyl benzene66700l
1,2,4 Trimethyl benzene15NA
1,3,5 Trimethyl benzene5.0NA
Xylenes (total)632000e
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


In November 1984 water samples from a private well approximately 500 feet south of the landfillcontained vinyl chloride. A sample taken from that same well earlier that year did not containcontamination. In June of 1989, that private well was replaced with a deeper well. The new wellwas also found to contain vinyl chloride, trichloroethylene, and 1,2 dichloroethylene. Table 4shows the contaminants detected at this home at their highest concentrations. Because vinylchloride exceeds its comparison value it is shown in bold type and is retained as a contaminant ofconcern for off-site groundwater. Table 5 is a summary of off-site monitoring well sampleresults from the remedial investigation. Again only vinyl chloride is considered a contaminant ofconcern for off-site groundwater. During the remedial investigation in 1993, 23 private wellswere sampled within a half mile of the site. None of the samples from these wells detectedcontaminants related to the site.

Table 4.

(9),(10) Residential Well Contamination
VOCMaximum DetectedConcentration (ppb)Comparison
Value (ppb)
1,2 Dichloroethylene1870l
Vinyl chloride470.2e
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
VOCMaximum Detected
Concentration (ppb)
Value (ppb)
1,2 Dichloroethylene4.070l
Vinyl chloride6.00.2e
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 inSeptember of 1989. There were four samples taken. One sample was taken in the basementwhile clothes were being washed. One was taken in a doorway between the living room andkitchen. Two were taken in the first floor bathroom, one of which was taken while the showerwas running. Table 6 shows the results of those samples analyzed for vinyl chloride.

(12)Results of Indoor Air Samples">

Table 6.

(12)Results of Indoor Air Samples
Sample LocationVinyl Chloride Concentration (ppm)
KitchenNot Detected
Bathroom w/Shower0.06

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 sitedetected VOCs. These samples were taken from excavations dug two to three feet below groundsurface in the wetlands. Samples taken in the wetlands during the remedial investigation did notcontain contamination, indicating that contamination is not discharging into the wetlands inmeasurable amounts.


In preparing this assessment, the WDOH relies on the information provided in the referenceddocuments and assumes that quality assurance and quality control measures were followedconcerning chain-of-custody, laboratory procedures, and data reporting. The validity of theanalyses and conclusions drawn for this assessment is determined by the reliability of thereferenced information.


The Toxic Chemical Release Inventory (TRI) was searched for chemical releases from the RiponFF/NN Landfill site and other facilities in the same zip code area. The landfill site was not listedin the TRI. No other releases were reported in the vicinity of the site.


There is no site access restriction to prevent people from walking across the site. There are nophysical hazards related to fire and explosion from the site, as it is not producing sufficientquantities of methane gas. Site slope and miscellaneous debris may present a slip/trip/fall typehazard.


This section describes exposure scenarios for known (completed) exposures and for exposuresthat may have occurred or could occur in the future (potential). These exposures are consideredalong with the toxicological information for the respective contaminants of concern to determinelikely health effects from the exposures.


There has been one documented completed exposure to contaminants from the Ripon FF/NNLandfill. VOC contamination in groundwater migrated south to a private residential watersupply approximately 500 feet from the site. The water supply was tested in 1984 and found tobe contaminated with vinyl chloride. The residents were advised by the WDNR and WDOH thatthe water should not be used for any purpose. They were also advised of the health risksassociated with using the water. In 1990 the WDNR abandoned the existing water supply well toprevent further use of the water supply. The residents using contaminated groundwater from thatwell ingested contaminants when drinking water, and inhaled contamination released from thewater during domestic uses (cooking, showering, etc.). The water supply may have beencontaminated a few years after waste disposal began. Because vinyl chloride is the onlycontaminant of concern for this pathway. A conservative estimate of exposure would assume theexposure began in 1984 when the contamination reached the residential well and ended when thewell was abandoned in 1990 (six years). It is also assumed that the vinyl chloride concentrationin that well was at its highest detected level (47 µg/L) for that seven year period. Theseassumptions lead to an exposure of approximately 4.7 µg/Kg/Day for a 10 Kg child drinking oneliter of water each day, and 1.3 µg/Kg/Day for a 70 Kg adult drinking two liters of water eachday.

No other completed exposure pathways exist at the site.


Residents living near the site rely on groundwater for their drinking water and other domesticuses. There is currently no exposure to contaminants from the site. There is a very low potentialthat contamination from the site could migrate to additional private wells. The nearest downgradient private wells are approximately 2000 feet from the site. The wetland to the southwest ofthe site lies between the site and those private wells, making it more unlikely for them to be atrisk of contamination from the site. If a private well were to become contaminated the residentsusing the contaminated groundwater from that well could ingest contaminants when drinkingwater; inhale contamination released from the water during domestic uses (cooking, showering,etc.); and absorb contaminants through their skin while bathing and washing in contaminatedwater.

Vinyl chloride is the only groundwater contaminant of concern at this site that could migratefrom the site at levels of health concern. For this reason no other groundwater contaminants ofconcern identified in Table 2 are considered for potential exposure pathways.

Another potential exposure could be caused by the existence of leachate seeps on the easternslope 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 walkingacross this portion of the site. Unsupervised children playing on-site could also ingest theleachate or leachate contaminated soils from this area. Interviews with nearby residents indicatedthat parents do not allow their children to enter the site. A general discussion of health effectsrelated to exposure to these seeps is included in the next section.


This section provides a discussion of possible health effects that could be related to completed orpotential exposures to contaminants identified in the Environmental Contamination Section.


Residential Well

     Vinyl Chloride
The completed exposure to vinyl chloride described in the previous section poses an increasedcancer risk to the residents who used the water for drinking and other domestic uses. Samplingconfirmed that there was exposure through ingestion as well as through inhalation during otherpotable uses. Vinyl chloride is a very potent human carcinogen. Low levels of exposure over anextended 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 vinylchloride 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 isnot expected to cause adverse health effects(14).

No adverse health effects are associated with exposure to naphthalene at the concentrations foundin the leachate. Such an exposure would have to include ingestion of nearly two liters of thelandfill leachate each day over the course of a lifetime before being considered a health concern.

No adverse health effects are associated with exposure to manganese at the concentrations foundin the leachate. Such an exposure would have to include ingestion of nearly one half a liter of thelandfill 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 consideredto 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. Theconcentrations 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 ofchemicals from the leachate are: skin irritation from the organic solvents in the leachate andpossibly the chromium at higher concentrations; respiratory irritation from inhalation of theVOCs and SVOCs(15),(16),(17),(18),(19). Such exposures have not existed in the past at the site and donot currently exist, as has been mentioned earlier in this document.


"Health outcome data" is a phrase referring to records of death and disease. When there isevidence that people near a site have been exposed to contaminants at levels that could lead to anincrease in rates of death or disease, a review of health outcome data may be appropriate. Areview 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 datareview is warranted as a result of this evaluation. There is an indication of exposure to vinylchloride that could pose an increased cancer risk. However, the exposure occurred at only oneresidence. A health outcome data review would not be appropriate for this site. Shouldadditional information of human exposures be found, a review of health outcome data will bereconsidered.


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 ofRipon. Chuck Warzecha and Mary Young also interviewed the residents living near the site inthe summer of 1993. In general the residents were well informed about the site and were notconcerned that the site could affect their health.

  1. A common concern expressed was that the groundwater contamination from the site not beallowed to enter private wells in the area.

    WDOH is recommending to the WDNR that a monitoring plan be established that wouldwarn 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 bethreatened by groundwater contamination from the site.

  2. Residents questioned what was coming out of the pipes sticking up out of the site. Theywanted to know if there was a health hazard posed by those pipes.

    The pipes are passive gas vents that allow landfill gasses to leave the landfill as they aregenerated. These vents have been monitored and indicate that the landfill is not producingmuch landfill gas. These vents are not expected to pose a health hazard to nearbyresidents.

  3. Several residents to the south of the site have been experiencing a problem with their privatewell water quality. The water is very turbid and has a strong "swampy" odor. The residentsquestion whether or not there could be a relationship between this problem and the site.

    In response to the concerns raised by these residents, the WDNR sampled some of the wellswith water quality problems. The sample results indicate that each well has an ironbacteria problem. The iron bacteria problem has no relationship to the landfill site. TheWDNR is working with the private well owners to identify a solution for the iron bacteria problem.

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