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HEALTH CONSULTATION

SOLVAY COKE BROWNFIELD
MILWAUKEE, MILWAUKEE COUNTY, WISCONSIN


SUMMARY

At the request of the United States Environmental Protection Agency (EPA), the Wisconsin Bureau of Environmental Health (BEH), under a cooperative agreement with the Agency for Toxic Substances and Disease Registry, prepared this public health consultation for the Solvay Coke and Gas site, Milwaukee, Wisconsin. Based on an interpretation of the site assessment report and site visits, BEH concluded that soil and groundwater beneath this former coke and manufactured gas facility is heavily contaminated with coal tars, but does not present an immediate public health threat. Buildings and other piping and exposed structures present physical hazards and are contaminated with coal tars and asbestos-containing material. People involved in demolition or other work on this property should be informed of the hazards present and be trained to address them. The redevelopment options for this property will be limited by the preceding degree of remediation. BEH supports the planned demolition of structures on site, recommends that coal tar wastes in soil be scheduled for removal, and recommends that all portions of the property and adjacent sediments be thoroughly evaluated for remediation.


BACKGROUND AND STATEMENT OF ISSUES

On May 23, 2002, the Wisconsin Bureau of Environmental Health (BEH) was asked by the United States Environmental Protection Agency (EPA) Region 5 to prepare a public health consultation to evaluate the human health implications of chemical contaminants and other health hazards on and beneath the Solvay Coke and Gas site (Solvay Coke), 311 East Greenfield Avenue, Milwaukee, Milwaukee County, Wisconsin.

Site background and demography. The former Solvay Coke site is situated on 46 acres of former marsh and waterfront property at the confluence of the Kinnickinnic and Milwaukee Rivers (figure 1). The facility produced coke and manufactured gas from 1902-1983, and at its peak operated 200 coke ovens (1). The manufacture of coke and gas are linked processes involving the pyrolytic heating of coal, resulting in the production of coke, coal tars, and fuel gas. At many of the former manufactured gas plants (MGPs) prevalent in Wisconsin, coke and tars were process wastes. At Solvay, coke production was a featured process and was shipped elsewhere for use as blast furnace fuel. The manufactured gas was presumably used locally. The manufacture of coke and gas are similar in the types of wastes produced, and it is expected that Solvay Coke and Gas will have soil and groundwater contamination consistent with other former manufactured gas plants. Solvay differs from other former MGPs in Wisconsin both in the large size of the operation and the possibility (unverified) that there was an intermittent market for coal tars produced there.

Since 1983, the Wisconsin Wrecking Company, a concrete recycler, has operated from the property, although most of the abandoned Solvay Coke buildings remain. The 46-acre property lies within a larger industrial corridor, exceeding 700 acres, along the Lake Michigan waterfront. The nearest residential neighborhood, an older, densely populated area with single-tract housing, lies approximately 1,800 feet west of the Solvay Coke buildings. Both residential and industrial water needs are served by municipal sources that are not affected by the Solvay Coke site. No known potable water wells exist in the area. Several other large industrial buildings and a railroad corridor lie between those residences and the Solvay Coke site. Access to the property is restricted by its relative isolation within waterfront and industrial neighbor boundaries, by a tall chain link fence, and by warning signs. However, the site perimeter is not entirely secure from trespass.

Site visit and statement of issues. BEH toured the site in December during the sampling phase of the EPA site assessment and later reviewed the site assessment report (2). Two sets of public health hazards are present at the site: physical and chemical hazards pertaining to on-site structures, and chemical contaminants in soil and groundwater beneath the site. The chemical and structure-related hazards include:

  1. Physical hazards presented by unoccupied, unsecured, deteriorated buildings.
  2. The possibility for dispersal of asbestos pipe insulation and damaged category I and II asbestos-containing material found with the buildings (3).
  3. Coal tars remaining within extensive aerial pipe work, within a storage pit on site, and in an aboveground tank.
  4. The migration of contaminants off-site through groundwater.
  5. The migration of contaminants off-site through air.
  6. Health effects from contact with soil and groundwater contaminants on sediments.

DISCUSSION

Physical hazards presented by unoccupied, unsecured, deteriorated buildings. The property contains several abandoned, multilevel buildings, aerial conveyors, and building debris that contain both physical hazards and chemical hazards including friable asbestos and deteriorating lead-era paint. Due to their deteriorated condition, entry into these buildings may be unsafe. Prior to removing asbestos-containing materials from these buildings, the structures should be assessed for imminent hazards.

Dispersal of asbestos pipe insulation during building demolition. The EPA Site Assessment Report (2) included sampling and inventory for asbestos containing materials (ACMs) in and around the buildings. The sampling and inventory focused on 2,745 feet of outdoor pipe insulation. The Site Assessment Report acknowledges that the sampling was preliminary and did not include asbestos-containing building materials other than the pipe wrap. It is not known whether non-inventoried ACMs are sufficiently friable to pose an environmental health threat to site workers. The removal of friable ACMS will require proper mitigation procedures to avoid environmental dispersion and direct exposure to workers during demolition.

Dispersal of other hazardous materials during building demolition. The industrial facilities located on this property may contain chemical hazards not included in the site assessment, such as mercury-containing gas regulators and PCB-containing electrical transformers. The buildings should be assessed for the presence of such devices, which should be safely removed prior to demolition.

Coal tars remaining within pipe work, within a storage pit on site, and in an aboveground tank. The presence of residual material in the extensive pipe works remaining from the coking and coal gasification facility has not been verified or characterized. If pipe residuals are found to contain coal tars, ammoniacal liquors (spent condensation waters of coal gas plants), or other process wastes, workers need to be cautious when handling hazardous materials to avoid direct contact or inhalation and to avoid unnecessary environmental contamination. Since pipes can be expected to leak or fail when being moved following disassembly, the demolition of pipes containing coal tars must include means to safely drain the pipes, if needed, prior to disassembly.

The migration of contaminants off-site through groundwater. The migration of coal tar wastes through groundwater into sediment is a common feature of former MGP sites. The high levels of mixed PAHs in sediments of the adjacent Kinnickinnick River (figure 1; table 1) suggests coal tars may have migrated off site to river sediments. However, a direct link between the coking plant and contaminants in the Kinnickinnick River, such as a waste outfall or a groundwater plume, has yet to be established.

The migration of contaminants off-site through air. Two groups of contaminants have the potential to disperse through air during their removal from this site: asbestos and coke/MGP wastes. Friable asbestos-containing materials in buildings should be removed prior to demolition to avoid dispersion. Hydrocarbons from coke/MGP processes that are present in soil may be released to air, particularly during the excavation of COKE/MGP waste soils. The high concentration of VOCs commonly found in COKE/MGP wastes presents a substantial risk of an airborne release of these volatiles upon excavation. The effect of these volatile releases on human health may range from a nuisance odor to acute respiratory effects. These effects vary with the specific compound, its concentration, and with the sensitivity of individual human receptors (4).

Effects of soil and groundwater contaminants on sediments. Sediments within the Kinnickinnick River are contaminated with metals, volatile organic compounds (VOCs), and PAHs at concentrations exceeding Wisconsin's consensus-based sediment quality guidelines (5) (table 1). These guidelines address environmental quality for aquatic biota, and are necessarily more stringent than would be required for humans who have occasional contact with these contaminants. The presence of concentrated PAHs and other coal tar constituents in river sediments is a health hazard in those instances of direct contact with these materials. This could occur when tars float to the surface after being stirred from sediment by boat mooring or other boat activity. People may then contact the tars either by contact with contaminated water, or by contact with boats soiled with tars. Based on current indications, cleanup of these sediments may not happen soon. An interim public health measure would be to place buoys and warning signs around those sediment areas most contaminated. Based on current information, these would be around the V-shaped boat mooring area and along the former coal staging area. Such access restrictions have been used with success near the site of coal tar-contaminated Lake Superior sediments around Kreher Park in Ashland, Wisconsin.

Hazards associated with future developments. The high concentration (table 2) of subsurface coal tar wastes around the former Solvay Coke facility is a potential health hazard to occupants of buildings that may be built at the site. The most probable exposure pathway to these subsurface contaminants is via vapor intrusion into subsurface basements. Volatile hydrocarbons present in groundwater or soils may be released as vapor and migrate into building foundations. Future uses of the property must quantitatively assess the probability of vapor migration from soils and groundwater into buildings and the effect on building occupants.

The southern portion of the property, the site of a former tannery, has been discussed as a potential site for redevelopment. The soil and water results for this part of the property reported in the EPA site assessment suggests that contamination in this area is relatively low. However, the sampling was limited to an initial survey. Given the historical use of the property as a tannery, higher levels of contaminants, especially metals, should be anticipated and may be discovered during future surveys. Total chromium in sediment near the site of the former tannery exceeds 1,700 ppm. Based on U.S. EPA Region III comparison values for total chromium III or chromium IV, these concentrations could pose a human health threat through incidental ingestion. The effect of direct contact with chromium in these sediments is not known at this time.

Short-term cleanup activities planned for the Solvay Coke site are not likely to remove every potential chemical hazard. Future activities on this site should be planned to minimize the potential for unsuspecting people to be exposed to remaining contaminants. Where buildings or other activities are planned in areas of the property with contaminant concentrations that do not demand removal, the potential for exposure can be minimized with clean overfill, landscaping, or a hard surface "cap" that is a barrier to exposure to contaminated strata.

Effects of occupational (chronic) exposure to coal tar. Coal tar, produced by the pyrolytic heating of coal in retort ovens, is a complex mixture of polycyclic hydrocarbons, aromatic hydrocarbons, phenols, and paraffin oils. The precise mixture varies with the source coal used and the temperature and duration of the retort process (6). Chronic occupational exposure to coal tars, by dermal contact or inhalation, produces lesions to skin and mucous membranes that begins with burning and itching and progresses to open sores and benign growths such as hardened skin patches and "tar warts." Several PAH structures may become carcinogenic after their structures are transformed to reactive epoxides. This oxidative transformation occurs following exposure to ultraviolet light (this can occur on the skin) or is catalyzed by oxidizing enzymes, known as cytochromes P450, within living cells. The PAHs with the greatest potential to be activated to reactive structures are dibenz[a,h]anthracene, benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and benzo[k]fluoranthene (7). Each of these materials was detected at high concentration (table 2) in exploratory pits reported in the EPA site assessment, particularly in area A around the Solvay Coke buildings. Direct contact or inhalation exposure to these substances may be expected during excavation work in the northwest quadrant of the property. The health effects of exposure to coal tar can be avoided with the use of worker personal protection. Workers should be trained to address the hazards of working with this material.


CHILD HEALTH STATEMENT

Abandoned buildings are attractive to exploration by children. The remoteness of the property from nearby residences, the presence of a fence around the property, and the few signs of trespass suggests that children have little access to the site and that the present exposure hazard to children is equally limited. However, the property is not entirely secure, and physical and chemical hazards are evident. Children who might enter the property are prone to these hazards.


CONCLUSIONS

The Solvay Coke site represents a public health hazard with regard to potential exposure pathways, especially if demolition crews are not experienced in working with hazardous waste. The immediate health threats at the Solvay Coke site are limited because the nearest residential neighborhood is approximately 1800 feet west of the site, the area is served by municipal water, and the property is secured with a chain-link fence. In addition to issues of environmental contamination, the property is being assessed for its redevelopment potential. Future development of the property will bring additional people onto the site and increases the potential for exposure to contaminants present in soil, sediment, and groundwater. The long-term options to improve the property will depend largely on the degree of remediation that occurs prior to redevelopment. Residential use of this property will require extensive remediation of soil and sediment. Furthermore, building improvements made without corresponding environmental improvements may be burdened with property restrictions and environmental liability due to the possibility of encountering substantial subsurface contaminants during future projects.

  • Contaminated groundwater beneath Solvay Coke is not a current source of drinking water to any humans, and is therefore not an immediate health threat.
  • Buildings on the property contain asbestos-containing pipe insulation and other materials that may expose workers and may be dispersed to the environment during building demolition.
  • Deteriorated buildings on the property may contain imminent structural hazards.
  • The industrial facilities located on this property may contain chemical hazards not included in the site assessment, such as mercury-containing gas regulators and PCB-containing electrical transformers.
  • The below-surface coal tars are a health threat that will affect future use of the property. The threats include vapor intrusion, direct contact to workers during construction work, and direct contact to users of the adjacent waterway through impacts to sediment.
  • Building demolition contractors typically are not equipped to deal with the coal tar materials (PAHs, VOCs, SVOCs, light oils, etc.) that are present in subsurface soils around the buildings in area A and that they are likely to encounter during the demolition of these buildings. It is likely that workers or their equipment will have direct contact with coal tar, and that some amount of coal tar will be left at the soil surface.
  • The mooring of boats along the Kinnickinnic River adjacent to the Solvay Coke site may disturb coal tar-contaminated sediments, increasing the potential for exposure for contact to tars in water or adhering to water craft or mooring lines.

RECOMMENDATIONS

  • The Wisconsin Department of Natural Resources should restrict the future placement of drinking water wells on this property.
  • BEH supports the removal of hazardous buildings, asbestos-containing materials, unstable pipe work, tanks, and other structures on the property.
  • BEH recommends that the city of Milwaukee require that the buildings be assessed, by a qualified inspector, for imminent structural hazardsprior to starting asbestos removal work.
  • The buildings should be similarly assessed for the presence of mercury-containing gas regulators, PCB-containing electrical transformers, or other devices containingchemical hazards.
  • The degree and extent of coal tar and other chemical contamination on the property should be assessed by state or federal environmental agencies.
  • In the interest of public health and worker safety, DPH recommends that the removal of foundations or below-surface structures also include plans to remove associated coal tar wastes.
  • In order to minimize contact with contaminated sediments, mooring restrictions should be placed, by the WDNR or U.S. EPA, along the Kinnickinnick waterfront around the V-shaped mooring area and along the former coal staging area.

PUBLIC HEALTH ACTION PLAN

  • The Wisconsin Department of Natural Resources (WDNR) is in agreement with restricting future placement of drinking water wells on the property.
  • The removal of asbestos-containing materials will be administered by the WDNR and/or EPA.
  • The city of Milwaukee, WDNR, and EPA are in agreement that buildings need to be assessed for asbestos and other possible hazards before deciding their fate.
  • WDNR and EPA will consider the degree to which further contaminant characterization and removal should be conducted prior to property reuse decisions.
  • WDNR is in the process of identifying potential responsible parties who will be asked to consider instituting mooring restrictions.

CONSULTATION AUTHOR

Robert Thiboldeaux
Toxicologist
Health Hazard Evaluation Unit
Bureau of Environmental Health
Division of Public Health
Wisconsin Department of Health and Family Services.


REFERENCES

  1. Budiarto F. 2001. Cost Assessment for remediation/redevelopment of a former manufactured gas plant site. Master's Thesis, Milwaukee School of Engineering, Milwaukee, WI.

  2. U.S. EPA. 2002. Milwaukee Solvay Coke and Gas Site. Site Assessment Report. Tetra Tech EM Inc. TDD No.: S05-0110-013.

  3. Wisconsin Administrative Code, Chapter NR 447.

  4. Wisconsin Department of Health and Family Services. 2002. Interim Guidance on Air Management at Former Manufactured Gas Plant Sites in Wisconsin. Jan. 28, 2002 Memo. to WDNR.

  5. Wisconsin Dept. Natural Resources. 2002. Consensus-Based Sediment Quality Guidelines; Recommendations for Use & Application. Pub. No. WT-732-2002.

  6. L'Epee P, Lazarini, HJ, Doignon J. 1983. Tar and Pitch. Pp2471-9 in Parmeggiani L, ed Encyclopedia of Occupational Health and Safety 3rd ed. Intl. Labour Office, Geneva.

  7. Agency for Toxic Substances and Disease Registry. 1995. Toxicological Profile for Polycyclic Aromatic Hydrocarbons. Atlanta, GA: US Department of Health and Human Services, Public Health Service.

Milwaukee Solvay Coke and Gas Site
Figure 1. Milwaukee Solvay Coke and Gas Site, Milwaukee, Wisconsin.


TABLES

Table 1.

Contaminants in sediments of the Kinnickinnic River adjacent to Solvay Coke, Milwaukee WI.a

Chemical
analyte
Mean sediment conc., mg/kg± std. error n=33 Comparison value mg/kg Commenta

Arsenic 10.0 ± 4.7 PECb 33  
Cadmium 4.7 ± 3.7 PEC 5.0  
Chromium 251.0 ± 441 PEC 110 Total chromium in sediment exceeds 1700 ppm near site of former tannery.
2-Butanone 0.06 ± .01    
Acetone 0.3 ± 0.3    
Benzene 2.9 ± 2.9 PEC 0.110 Site MC-SD-D-005-0405 92 ppm, most others < 0.05
Carbon disulfide 0.1 ± 0.002    
Methylene chloride 0.02 ± 0.01    
Xylenes 2.5 ± 2.5 PEC 0.050 Site MC-SD-D-005-0405 81 ppm, most others < 0.05
Toluene 2.7 ± 2.8 PEC 1.8 Site MC-SD-D-005-0405 90 ppm, most others < 0.05
Anthracene 3.6 ± 0.7 PEC 0.85  
Benz(a)anthracene 8.3 ± 0.9 PEC 1.05  
Benzo(a)pyrene 6.1 ± 0.8 PEC 1.45  
Benzo(b)fluoranthene 8.4 ± 0.9 PEC 13.40  
Benzo(g,h,i)perylene 3.9 ± 0.6 PEC 3.20  
Benzo(k)fluoranthene 6.6 ± 0.626 PEC 13.40  
Chrysene 10.0 ± 1.0 PEC 1.30  
Dibenz(a,h)anthracene 1.8 ± 0.3 PEC 0.14  
Fluoranthene 18.0 ± 1.703 PEC 2.20  
Phenanthrene 14.4 ± 1.7 PEC 1.17  
Pyrene 15.4 ± 1.8 PEC 1.52  
Arochlor 1254 1.9 ± 0.5 PEC (total PCBs) 0.68  

aData summarized from: U.S. EPA. 2002. Milwaukee Solvay Coke and Gas Site. Site Assessment Report.
Tetra Tech EM Inc. TDD No.: S05-0110-013.
bPEC: probable effect concentration, WDNR consensus-based sediment quality guidelines.


Table 2.

Contaminants in soils around coking facility buildings (operable unit A) Solvay Coke site, Milwaukee WIa

Chemical
analyte
Mean soil conc., ± std. Error mg/kg Comparison value mg/kg

Xylenes 16.6 ± 13.2 n=11 400b
Toluene 1.193 ± 0.7 n=14 40b
Naphthalene 378.0 ± 230.4 n=15 400b
Benzene 2.5 ± 1.5 n=14 10 CREG0c
Anthracene 74.2 ± 49.9 n=12 20,0000b
Benzo(a)anthracene 79.8 ± 51.8 n=12 EPA B2d
Benzo(a)pyrene 60.5 ± 44.0 n=11 0.1CREG
Benzo(b)fluoranthene 46.5 ± 28.5 n=11 EPA B2
Benzo(g,h,i)perylene 11.9 ± 6.2 n=10 EPA De
Benzo(k)fluoranthene 55.6 ± 34.9 n=12 EPA B2
Chrysene 78.5 ± 47.6 n=12 EPA B2
Dibenz(a,h)anthracene 7.0 ± 3.9 n=8 EPA B2
Fluoranthene 175.8 ± 122.6 n=13 800b
Phenanthrene 273.6 ± 184.9 n=13 EPA D
Pyrene 152.3 ± 102.9 n=14 EPA D

a Data summarized from: U.S. EPA. 2002. Milwaukee Solvay Coke and Gas Site. Site Assessment Report. Tetra Tech EM Inc. TDD No.: S05-0110-013.
b EMEG, child pica (Environmental Media Evaluation Guide, Agency for Toxic Substances and Disease Registry) .
c Cancer Risk Evaluation Guide, Agency for Toxic Substances and Disease Registry.
d EPA cancer class, probable human carcinogen.
e Under review for EPA cancer classification.


CERTIFICATION

This public health consultation for the Solvay Coke Brownfield Site in Milwaukee, Wisconsin was prepared by the Wisconsin Department of Health and Family 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 health consultation was begun.

Gail D. Godfrey
Technical Project Officer, S.P.S., SSAB, DHAC


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

Sven E. Rodenbeck
for Roberta Erlwein
Chief, State Program Section, DHAC, ATSDR


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