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HEALTH CONSULTATION

ST. FRANCIS AUTO WRECKERS
ST. FRANCIS, MILWAUKEE COUNTY, WISCONSIN


SUMMARY

The Wisconsin Bureau of Environmental Health was asked by the Wisconsin Department ofNatural Resources to evaluate the St. Francis Auto Wreckers property. The property consists ofa fenced auto salvage yard and an unfenced wooded vacant lot adjacent to a residentialneighborhood. Children use the vacant lot as a play area. Subsurface soils (below one foot deep)on both parts of the property are contaminated with elevated levels of polychlorinated biphenyls(PCBs), volatile organic compounds (VOCs), lead, and chromium. Surface soil at the salvageyard contains PCBs that are a direct contact hazard. Bare foundry sand at the soil surface of thevacant lot suggests a contact hazard also exists there; however, the soil data for that area areincomplete. The Wisconsin Bureau of Environmental Health (BEH) recommends further soilcharacterization and that the vacant lot be fenced and posted with hazard signs to limit access.


BACKGROUND AND STATEMENT OF ISSUES

The Wisconsin Department of Natural Resources (WDNR) requested that the Wisconsin Bureauof Environmental Health (BEH) assess health hazards pertaining to soil contaminants at the St.Francis Auto Wreckers site. St. Francis Auto Wreckers is located at 4043 S. PennsylvaniaAvenue, St. Francis, Milwaukee County, Wisconsin. Part or all of the property is the earlier siteof an unregistered landfill known as the "Town of Lake Dump"(1). The St. Francis AutoWreckers property is divided into two halves, each having somewhat different public healthissues. The southern half is the fenced salvage yard; the northern half is a partially wooded,unfenced vacant lot. PCBs, toxic metals, and VOCs, have been detected in soil throughout theproperty (2,3,4). Potential receptors for these contaminants are workers and visitors within thesalvage yard and residents north of the property that might visit the vacant lot.

Site visit. BEH staff visited the property in July 2001. The salvage yard on the southern 1.8acres of the property is surrounded by a tall fence that is an adequate barrier to unauthorizedentry. A portion of the property immediately north of the salvage yard is a partially wooded,unfenced vacant lot of approximately 1.6 acres. Part of the western edge of the property hasbeen converted to highway right-of-way during an expansion of Lake Parkway in recent years. Landfill has raised the level of the vacant lot several feet above the bordering roads to the northand east. The perimeter and part of the interior of the lot is partially wooded. Much of theinterior of the lot is sparsely vegetated and covered with red foundry sand. Some concrete andwire building debris and a steel barrel border the northern edge of the lot. BEH staff foundevidence that children play on the vacant lot. A makeshift shelter on the edge of the lot appearsto be a child's play site. Demographically, the surrounding area is suburban mixed industrialand residential properties. Approximately 100 people reside within 300 meters of the property;about 750 people reside within 600 meters (estimates from 1995 aerial photo). Two residentialapartment buildings are across the street north of the property. The suburban residential areacontinues northward.


DISCUSSION

Soil investigation reports from 1991, 1997, and 2000 indicated the presence of elevated levels of polychlorinated biphenyls (PCBs), metals, and petroleum-related volatile organic compounds (VOCs) (2,3,4). Two surveys from 1991 report elevated PCBs in soil samples taken from depths of one foot or less. The 1991 data report indicated total PCB concentrations in the salvage yard of 22.5 6.1 µg/gm (mean std. error, n=11) (2). Other 1991 data report total PCBs in 0-0.5 feet deep soils within the salvage yard at 9.1 4.0 µg/gm (mean std. error, n=15) (3). In neither soil investigation were surface soil samples collected from the vacant lot. Later samples collected in 2000 contained elevated levels of PCBs (0.5-1.6 µg/gm) in two-foot deep soils (2).

Elevated concentrations of metals have been detected in surficial and deep soils throughout the property. These metals possibly result from foundry sand deposited in the landfill that operated prior to the salvage yard. Most soil samples (2000 survey) were subsurface samples because they were taken from greater than 2 feet deep (2). However, two samples collected from a depth of 0.5 feet in the area of the vacant lot next to the salvage yard contained elevated levels of barium (1,800 µg/gm), cadmium (40.1 µg/gm), chromium (29.2 µg/gm), lead (646 µg/gm), arsenic (6.1 µg/gm), and mercury (46.6 µg/gm). These concentrations exceed the Wisconsin Administrative Code ch. NR 720 standards for non-industrial contaminants. The lead and arsenic levels exceed NR 720 standards for industrial sites. Comparable metal concentrations were reported from deeper soil samples.

Soil contaminants found on this property may affect groundwater through leaching. The effectof any leaching on local aquifers is the subject of current groundwater investigations (5).

There are two major scenarios by which exposure to soil contaminants might occur at the St. Francis Auto Wreckers property. The first is exposure to people, especially children, visiting the vacant lot, as discussed under the child health statement. The second is to workers within the salvage yard. Of these, exposure via the vacant lot is the greater risk to public health. It is also the area where more information is needed to conclusively assess the public health threat. Based on currently available data, much of the known health risk at this site is to workers within the fenced salvage yard and would result from direct contact with contaminants in the upper 2 inches of soil. However, more environmental assessment is needed here as well. Only a few soil samples from the 6" soil depth within the salvage yard have been analyzed. A sample from 6" deep may not be representative of PCB contamination at the soil surface, where exposure is likely to occur. The samples, which were taken in 1991, contained elevated PCBs ranging from approximately 1-50 µg/gm throughout the salvage yard (2). An environmental comparison value, the cancer risk evaluation guide (CREG) for PCBs, has been established by the Agency for Toxic Substances and Disease Registry. The CREG is an estimate of a contaminant in an environmental medium in which an excess 1 in 1,000,000 cancer risk might occur following a lifetime exposure to soils that contain 0.4 µg/gm PCBs. Because the salvage yard is an active work site, the current contamination in surface soil may not be similar to that found ten years ago. Subsequent samples have not been shallow enough (approx. 2" depth) to support an evaluation of possible effects from direct contact with surface soils. If additional investigation identifies contaminants in surface soils similar to that found at depth, the direct contact risks can be addressed. The need for surface soil tests emphasizing PCBs, metals, and PAHs are appropriate because the presence of each of those classes of compounds can be expected in surface soils around an auto salvage operation of this type. Each compound class includes substances that are toxic and are persistent in soil. In this case, VOCs are less likely to be a direct contact concern because they are not persistent in surface soil.

Because PCBs, petroleum hydrocarbons, and metals are present in the soils, there is concernover the potential for exposure to these compounds. This exposure could occur through eitherdirect contact with these soils or through incidental ingestion or inhalation of these soils. Thepotential for exposure would range from minimal, such as to someone walking casually throughthe property, to a large exposure to someone digging or playing in these soils. The potential forcasual exposure can be assessed by (1) knowledge of the contamination at the soil surface (1-2inch depth) and (2) the thickness of plant cover. At the St. Francis Auto Wreckers property thereis known soil contamination in both the salvage yard and the vacant lot. However, sampling datathat adequately addresses contamination in the direct contact zone at the soil surface isincomplete. Previous soil surveys suggest that significant surface contamination is present, andthe lack of soil cover, either plant or barrier, allows the possibility of incidental contact withsurface contaminants.

Table 1.

PCBs and metals detected in soil from the St. Francis Auto Wreckers salvage yard and adjacent vacant lot.
Contaminant concentration
(µg/gm)
location sample depth comparison value
PCBs (total) 221 salvage yard 0-1.0 ft. 0.4 µg/gm CREG4
PCBs (total) 9.12 salvage yard 0-0.5 ft. 0.4 µg/gm CREG4
PCBs (total) 0.5-1.63 vacant lot 2 ft 0.4 µg/gm CREG4
cadmium 40.1 vacant lot5 0-1.0 ft. 8/510 µg/gm (residential/insustrial)6
chromium 29.2 vacant lot5 0-1.0 ft. NA, valence unknown
lead 646 vacant lot5 0-1.0 ft. 50/500 µg/gm (residential/insustrial)6
arsenic 6.1 vacant lot5 0-1.0 ft. 0.039/1.6 µg/gm (residential/insustrial)6
mercury 46.6 vacant lot5 0-1.0 ft. 23/610 µg/gm (residential/insustrial)7

1 1991, reference 2
2 1991, reference 3
3 2000, reference 2
4 Cancer risk evaluation guide, 1x10-6 lifetime excess cancer risk
5 Sample from drainage swale on the southern edge of the vacant lot, reference 2.
6 Reference 6
7 Reference 7. Note: inorganic Hg assumed.


CHILD HEALTH STATEMENT

The vacant lot immediately to the north of the salvage yard requires further attention andinvestigation because children could be coming in contact with contaminants in soil at levels thatmight harm them. Children are particularly susceptible to lead and PCBs. Because this partiallywooded lot is unfenced and adjacent to a residential neighborhood, it is accessible and attractiveto exploration by children. A makeshift shelter on the edge of the lot appears to be a child's playsite. No analysis of surface soils from the vacant property has been conducted. This lot shouldalso be assessed for physical hazards that may require fencing or clean-up.


CONCLUSIONS

BEH concludes, based upon the presence of contaminated foundry sand, construction debris, andevidence of children playing on the vacant lot, that a Public Health Hazard exists on this part ofthe property. Based on available information, there is also a health hazard, via direct contactwith PCB-contaminated soils, to workers in the salvage yard. Current analyses of contaminantsat the soil surface of the vacant lot are not yet available, but the presence of bare foundry sandthroughout the lot supports the need for testing for toxic metals, such as lead and chromium, andPCBs.


RECOMMENDATIONS

The 1991 and 2000 soil analyses should be confirmed with additional, surface soil analyses forPCBs, metals, and PAHs.

Additional testing should be conducted for contaminants in the surface (1-2 inches) soil bothwithin the salvage yard and adjacent vacant lot, and additional assessment of the vacant lot forphysical hazards that could harm children should be done.

If lead in surface soils is elevated, nearby children should be screened, in cooperation with theSt. Francis Health Department, for elevated blood lead levels.

A fence and hazard postings are recommended for the vacant lot in order to limit access tohazards on site. BEH also recommends a groundwater evaluation, as is planned.


PUBLIC HEALTH ACTION PLAN

The owner of the St. Francis Auto Wreckers has retained an environmental consultant to furthercharacterize the soil and groundwater beneath the property. These results will be submitted toWDNR; BEH will review additional sample results.

Contact with surface contamination within the salvage yard is currently managed by applyinggravel fill and grading the surface. Pending further investigation, WDNR may require, and BEHmay recommend, further remedy, such as capping the yard surface with asphalt.

With regard to the vacant lot, the owner apparently intends to develop this portion of theproperty with an asphalt cover, building, and fence. BEH supports this plan to the extent that itwill cap and limit direct contact with soil contaminants. As a short-term solution, the vacant lotwill be fenced and posted with no trespassing signs.


CONSULTATION AUTHOR

Robert Thiboldeaux, Ph.D.
Toxicologist
Health Hazard Evaluation Section
Bureau of Environmental Health
Division of Public Health
Wisconsin Department of Health & Family Services


REFERENCES

  1. Personal communication from Nancy Ryan, WI Dept. Natural Res. to RobertThiboldeaux, WI Bureau Env. Health. July, 2001.

  2. Hall, D. Soil Investigation Report, St. Francis Auto Wreckers, Inc., St. Francis,Wisconsin. Montgomery Watson, April 2000, project #12422146.03160101.

  3. Fieber, BM and Huibregtse, KR. PCB results letter, June 27, 1991. Howard NeedlesTammen & Bergendoff, STS Project 83417XF.

  4. Bremer, JJ. 1998. Remediation documentation report for the WisDOT-Autowrecker'sproperty, St. Francis, Wisconsin. Lake Parkway Project 1300-05-79. RMT, Inc.Madison WI.

  5. Ryan, ND letter to Robert Melton. Wisconsin Department of Natural Resources,FID#241469250 BRRTS#0210000269. August 3, 2000.

  6. Wisconsin Administrative Code, ch. NR 720.02. Soil Cleanup Standards, January, 2000.

  7. United States Environmental Protection Agency. Risk-Based Concentration Table,Region III. April 1999.

CERTIFICATION

This public health consultation for the St. Francis Auto Wreckers Site was prepared by theWisconsin Department of Health and Family Services under a cooperative agreement with theAgency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approvedmethodology and procedures existing at the time the Public Health Consultation was begun.

Gail D. Godfrey
Technical Project Officer, SPS, SSAB, DHAC


The Division of Health Assessment and Consultation, ATSDR, has reviewed this Public HealthConsultation and concurs with the findings.

Lisa C. Hayes
for Chief, State Program Section, DHAC, ATSDR


Table of Contents

  
 
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