REILLY TAR & CHEMICAL CORPORATION SITE
ST. LOUIS PARK, HENNEPIN COUNTY, MINNESOTA
The Reilly Tar and Chemical Corporation Site (Site) is listed on the U.S. Environmental Protection Agency's (EPA) National Priorities List. The Site is located in the city of St. Louis Park, in eastern Hennepin County, Minnesota.
From 1917 until 1972, the Reilly Tar and Chemical Corporation (now known as Reilly Industries, Inc.; Reilly) operated a coal tar distillation and wood preserving plant, known as the Republic Creosote Company, on the Site. The spilling of coal tar and creosote on-Site, and the discharge of contaminated wastewater off-Site during plant operations resulted in the contamination of soil and area aquifers with polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds.
Contamination of local wells with Site-related chemicals was first documented in the 1930's. Throughout subsequent years, there were numerous reports of contaminated wells and complaints from the local community about odors and soil and surface water contamination. In 1978, the Minnesota Department of Health closed six municipal wells in St. Louis Park and one well in neighboring city of Hopkins because of contamination with PAHs. These compounds are found in relatively high concentration in both coal tar and creosote.
In 1972, the city of St. Louis Park purchased the Site from Reilly and the plant facility was dismantled. A major portion of the Site is currently used as a park. There are also three apartment complexes, light industries, and small business located on-Site. The areas surrounding the Site on the west, north, and east are primarily composed of single-family residences; there is primarily light industry to the south of the Site.
Local residents use municipal water drawn from aquifers contaminated with low levels of PAHs. Exposure to these compounds may occur via ingestion of and dermal contact with potable water. However, concentrations of PAHs in the water from several municipal wells are closely monitored to assure that they are below Drinking Water Criteria. These Drinking Water Criteria were derived through a joint effort between the MDH, MPCA, and EPA, and are defined as the recommended maximum permissible concentrations of PAHs in drinking water which provide for the protection of human health. Finished water supplies (that is, water obtained at the tap) are not monitored for PAHs.
In a 1979 epidemiological study, MDH found a statistically significant increase in the incidence of breast cancer in St. Louis Park females (cancer data from the Third National Cancer Survey for the years 1969 to 1971 were analyzed). In a 1985 report to the Minnesota Legislature entitled "Feasibility of Community-Wide Epidemiologic Studies of Drinking Water and Health: St. Louis Park & New Brighton", the MDH concluded that it was unlikely that the observed excess of breast cancers in St. Louis Park could be related to [ingestion of] water contaminants.
A potential route of human exposure to Site-related chemical contaminants currently exists because gullying and erosion of the hill on the southwestern portion of the Site may be exposing previously inaccessible, contaminated soil. This hill was formed when visibly contaminated soil and demolition debris were excavated/moved from other parts of the Site following the dismantling of the plant buildings and the construction of on-Site housing units.
The final agreement for the remediation of the Site is outlined in the 1986 Consent Decree-Remedial Action Plan. Many provisions of this document are completed, and others are currently being carried-out.
MDH will follow the progress of investigations and clean-up activities at the Site. MDH will, at the request of the appropriate parties (for example, the MPCA), review reports or progress updates prepared by those carrying out clean-up activities.
The data and information developed in this public health assessment have been evaluated by the Agency for Toxic Substances and Disease Registry (ATSDR) Health Activities Recommendation Panel for follow-up health actions. Although human exposure to site contaminants is currently occurring via drinking water use, this exposure is not occurring at levels of public health concern. A community health education effort related to this site has been undertaken. This site is not being considered for additional follow-up health activities at this time. However, if data become available suggesting that human exposure to hazardous substances at levels of public health concern is occurring, ATSDR and MDH will re-evaluate this site for any additional follow-up health activities.
Based on the information and data reviewed, the MDH concludes that the Reilly Tar and Chemical Corporation site poses no apparent public health hazard.
A. Site Description and History
The Reilly Tar and Chemical Corporation Site (Site) is listed on the U.S. EPA's National Priorities List. The Site is located in the city of St. Louis Park (City), in eastern Hennepin County, Minnesota (Figure 1). The boundaries of the 80-acre Site are as defined in the Remedial Action Plan program of the 1986 Consent Decree (1). The approximate location of the Site is west of Gorham and Republic Avenues, south of 32nd Street, east of Pennsylvania Avenue, and north of Walker Street (Figure 2).
From 1917 to 1972, the Reilly Tar and Chemical Corporation (now known as Reilly Industries, Inc.; Reilly) operated a coal tar distillation and wood preserving plant, known as the Republic Creosote Company, on the Site. Plant operations consisted of the high temperature distillation of coal tar to produce creosote, which was subsequently used as a wood preservative. The bulk of the plant's operations took place in the south-central and southeastern portions of the Site. It was in these areas that the coal tar distillation still, wood-treating building, and above ground and underground storage tanks (for creosote, tars, pitch, and fuel oils) were located. From 1917 to 1939, raw waste water containing coal tar and creosote was discharged into a drainage ditch that originated in the northern portion of the Site and ran the length of the Site (approximate path was NE to SW). Historical aerial photographs show the northern portion of the Site possibly contained a waste disposal area. Once off-Site, the drainage ditch connected with a series of other ditches which eventually emptied into a small marsh approximately 600-700 feet south of the Site. In 1940/1941, Reilly installed a waste water treatment plant, but continued to discharge the effluent off-Site until operations ceased in 1972. Typical concentrations of phenolic compounds and oil and/or grease in this wastewater varied between 100 and 1,000 mg/L. The effluent that collected in the marsh eventually discharged to the Minnehaha Creek approximately 2,250 feet south of the Site. Chemical contaminants may have also been released from a waste pond located in the main coal tar distilling/wood preserving area in the SE corner of the Site. Soil contamination with coal tar and creosote occurred in this, and other portions of the Site, via drips from leaky piping, precipitation wash-off from stockpiled treated lumber, and spills of process materials throughout the operational history of the Republic Creosote Company.
Figure 1. Location of the Reilly Tar and Chemical Corporation Site
Figure 2. Detailed Map of the Reilly Tar and Chemical Corporation Site and Surrounding Areas
In addition to contaminating soil and surface water, the release of coal tar and creosote from the Site resulted in the contamination of the area's groundwater. The contamination of area aquifers may have occurred by one or more of the following processes: 1) the direct downward infiltration of chemicals through the soil from waste pond(s) and the marsh, 2) via multi-aquifer wells in the area of the Site, 3) direct injection or overflow of wastes into on-Site well(s),and 4) via a buried bedrock valley southeast of the Site which connects the Drift-Platteville aquifer with the St. Peter aquifer (see below).
The Site overlies six regional aquifers. A brief introduction to these aquifers (starting at ground level) is presented below:
The Platteville Aquifer - This is the first bedrock aquifer encountered under the Site. It is hydrologically connected to the surficial Drift. Because of this connection, the surficial Drift and Platteville aquifers are often considered as one aquifer (Drift-Platteville). Groundwater flow in this aquifer is toward the east.
The St. Peter Aquifer - This aquifer is separated from the Drift-Platteville by the thin Glenwood confining bed. Groundwater movement in this aquifer is toward the southeast.
The Prairie du Chien-Jordan Aquifer - This aquifer is separated from the St.Peter by the Basal St. Peter confining layer. The Prairie du Chien-Jordan is the region's major groundwater resource. Approximately 75-80% of groundwater withdrawals in the St. Louis Park and Minneapolis-St. Paul Metropolitan areas are from this aquifer. Groundwater in this aquifer moves in an east-southeast direction, but can be significantly affected by pumping stresses from municipal and industrial wells in the region.
The Ironton-Galesville Aquifer - This aquifer is not highly productive and is not utilized in the area.
The Mt. Simon-Hinckley Aquifer - This aquifer is separated from the Ironton-Galesville by the Eau Claire confining bed. The Mt. Simon-Hinckley is the deepest (800-900 feet below the surface) productive aquifer in the Minneapolis-St. Paul Metropolitan area.
On-Site and off-Site groundwater and soil contamination with coal tar and creosote has been documented since the early 1930's (2-5). Both coal tar and creosote are complex mixtures of organic compounds. The major constituents of coal tar are phenolic compounds (phenolics) such as phenol, cresols, and methylphenols, and polycyclic aromatic hydrocarbons (PAHs). Creosote is composed primarily of PAHs (75-80%) such as naphthalene, phenanthrene, fluoranthene, acenaphthene, fluorene, and pyrene, but phenolic compounds such as phenol, cresols, and methylphenols are also present (2-17%). The following is a brief chronology of chemical contamination of the Site and surrounding area:
| 1) | In 1932, the City drilled it's first municipal well approximately one-half mile east of the Site in the Prairie du Chien-Jordan aquifer. The well had to be closed within weeks of start-up because the water had a coal tar taste and odor problems. |
| 2) | In 1933, another Prairie du Chien-Jordan well one mile east of the Site was found to be contaminated with a coal tar taste. |
| 3) | In 1938, the Minnesota Department of Health documented both the discharge of contaminated waste water to ponds south of the Site and the contamination of wells near the Site with phenolic compounds. |
| 4) | During the 1930's and 1940's, several private wells finished in the Drift-Platteville exhibited contamination. |
| 5) | Complaints from nearby residents regarding the contamination of shallow wells became common in the late 1940's into the 1950's. |
| 6) | In 1958, a large plug of coal tar of unknown origin was discovered in an on-Site water supply well. This coal tar plug directly contaminated the Prairie du Chien-Jordan and Ironton-Galesville aquifers. |
| 7) | Sampling conducted during the 1970's and in 1988 confirmed that on-Site and off-Site subsurface soils were contaminated with PAHs, phenolics, and unidentified organic contaminants referred to as benzene-extractables. |
| 8) | Wells in St. Louis Park were first sampled for PAHs 1978. At that time, several wells were shown to have low, but detectable levels of carcinogenic and non-carcinogenic PAHs. However, four Prairie du Chien-Jordan municipal wells (SLP 10,15,7, and 9) had obviously higher levels of PAHs. Carcinogenic PAHs (benzo[a]pyrene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene) were detected in SLP 10 and 15 at concentrations of less than 10 ng/L; none were detected in SLP 7 and 9. Non-carcinogenic PAHs (anthracene, pyrene, fluoranthene, and naphthalene) were detected in the four wells at concentrations ranging from 10-1000 ng/L. In subsequent years, these PAHs, as well as other carcinogenic and non-carcinogenic PAHs, were being consistently detected in other Prairie du Chien-Jordan municipal wells. Between 1978 and 1981, the MDH closed six Prairie du Chien-Jordan municipal wells in St. Louis Park (SLP 4,5,7,9,10,and 15) and one in neighboring city of Hopkins (Hopkins 3) because of PAH contamination. |
Because of continuing problems with odors, and soil and surface water contamination, the City and the MPCA filed a lawsuit against Reilly in October, 1970. In April, 1972, the City purchased the Site from Reilly and, as a condition of the sale, dropped its lawsuit against Reilly. In June, 1973, the City deeded the Site to the St. Louis Park Housing and Redevelopment Authority which subsequently sold portions of the Site to three private parties. The MPCA amended it's original lawsuit against Reilly in April, 1978 alleging that Reilly's coal tar and creosote wastes contaminated the area's groundwater with PAHs, and that further migration of PAHs threatened aquifers used for public water supplies. To compel Reilly to undertake necessary remedial actions, further legal and administrative actions were taken by federal and state agencies during 1978 - 1985. The final agreement for the remediation of the Site was reached in 1985 and is contained in the Remedial Action Plan (RAP) portion of the September 1986 Consent Decree-Remedial Action Plan (CD-RAP) (1). The objectives of the RAP are to: 1) provide a safe drinking water supply in sufficient quantity for the City and surrounding communities, 2) control the spread of contamination in the regional aquifers, 3) allow for safe, reasonable, and beneficial use of the Site and adjacent contaminated areas, and 4) preserve and protect groundwater resources for present and future uses. The fulfillment of the RAP portion of the CD-RAP will constitute the full settlement of all pending claims against Reilly Tar and Chemical Corporation.
Much of the Site is currently designated as, and is used as a park. The majority of the Site is relatively flat and vegetated with grass. Three rental condominium and/or apartment complexes are located in the northern and central portions of the Site. There are commercial properties and light industrial facilities on the eastern edge of the Site. There are primarily private and multi-family residences bordering the Site to the west, north and east, and light industries to the south.
Because of the complexity of the on- and off-Site groundwater and surficial contamination and proposed response actions, the RAP divided the remediation of the Site into functional components called "operable units." This Public Health Assessment for the Reilly site will discuss the contamination, as well as any completed, on-going or proposed remedial actions in terms of these operable units. The three operable units (and their components) are:
A number of remedial activities for the operable units were specified in the RAP. In addition, remedial activities were also performed at the Site prior to the institution of the RAP. The major remedial activities which have either been completed or are currently in progress are discussed below:
An off-Site Drift aquifer contaminant source control well (W420) and a Platteville contaminant source control well (W421) were installed in October, 1987. Both wells are south of the Site. Between 1988 and 1991, discharged groundwater was routed to the sanitary sewer system for treatment at the Metropolitan Waste Control Commission (MWCC) wastewater treatment plant. The construction of a granular activated carbon (GAC) treatment system for removing organic contaminants from the discharge water was completed in late 1990. GAC-treatment of groundwater with discharge to Minnehaha Creek began in June, 1991 and will continue for a minimum of five years, at which time a direct discharge will be considered by the MPCA, providing the discharge meets surface water discharge limits.
An off-Site contaminant gradient control well (W422) was installed in October, 1987. This well currently discharges groundwater to the sanitary sewer for treatment at the MWCC plant.
The City of St. Louis Park completed a Remedial Investigation (RI) for the area directly east of the Site (referred to as the Northern Area) in June, 1989. A supplemental RI and the Feasibility Study (FS) outlining potential remedial actions for the Northern Area was submitted by the City in July, 1991. The MPCA proposed a cleanup plan for the Drift Aquifer (Northern Area) in August, 1992. The plan is to continue using W422 but to augment it with one or more additional pumping wells. A cleanup plan for the Platteville Aquifer will also be made by MPCA.
Starting in 1991, 20 Drift-Platteville monitoring wells will be sampled twice yearly. The CD-RAP allows for additional source and/or gradient control wells or the modification of these well(s) contingent on sampling results.
The City of St. Louis Park submitted a final RI report for the St. Peter aquifer in September, 1989. As part of the associated FS, well number W410 was recompleted and evaluated for it's ability to control the spread of the contaminant plume in the aquifer. A ROD was signed by EPA and MPCA in September, 1990. Under the ROD, W410 is to be pumped to intercept and contain the contaminant plume. W410 is now operational with groundwater discharge routed to the sanitary sewer for treatment at the MWCC wastewater treatment plant. The MPCA anticipates that, within three to five years, the quality of the groundwater pumped from W410 will have improved sufficiently to meet National Pollutant Discharge Elimination System (NPDES) limits and thus can be discharged to Minnehaha Creek.
The continued monitoring of this aquifer's water level and water quality (for example, PAH concentration) is also a requirement of the ROD. If water quality does not improve over the three to five year pumping period, and the City intends to discharge to Minnehaha Creek, an on-Site treatment facility will be built to ensure that the discharged groundwater meets NPDES limits.
On-Site well W23, which was contaminated with coal tar, was cleaned-out in 1981 under a Cooperative Agreement between EPA and MPCA.
An EPA ROD for the installation of a GAC treatment system for St. Louis Park Municipal wells 10 and 15 was signed in June, 1984. These municipal wells are located approximately 2000 feet north of the Site. The GAC treatment system began operation in 1986. The RAP stipulates that the treatment system will operate whenever the wells are used to supply the City's potable water distribution system.
The on-Site multi-aquifer well W23 was reconstructed as a Prairie du Chien-Jordan well and is being used as a source control well. The groundwater discharge from W23 is routed to the GAC treatment facility currently treating the discharge from Drift-Platteville source control wells W420 and W421. The treated water is discharged to Minnehaha Creek.
A St. Louis Park well (SLP 4) is currently being used as a gradient control well. This well is approximately 1-1/4 miles SE of the Site. The RAP also required the installation of three new monitoring wells to assess the performance of this well as a gradient control system. If the gradient control system does not operate as required, the pumping rate of SLP 4 will be modified or additional gradient control wells will be installed.
The EPA and MPCA gave authorization to the City to stop pumping On-Site well W105 on December 4, 1991. The City will begin periodic monitoring of the well to ensure that Drinking Water Criteria are not exceeded. In addition, if any municipal Ironton-Galesville well is installed within one mile of on-Site W23, it must be sampled annually for PAHs.
The only action for this aquifer required by the RAP is the annual monitoring (30 years) of four municipal drinking water wells for PAHs. The wells that are currently being sampled, as well as their distance and direction from the Site, are: 1) Well SLP 11, approximately 2000 feet north, 2) Well SLP 12, approximately 6625 feet south, 3) Well SLP 13, approximately 7500 feet north, and 4) Well SLP 17, approximately 2875 feet east.
In addition, if any municipal Mt. Simon-Hinckley well is installed within one mile of on-Site W23, it must be sampled annually for PAHs.
In 1978-1979, twenty-nine multi-aquifer wells were abandoned in areas where the surficial aquifers were most contaminated with PAHs and/or phenolics.
The two on-Site multi-aquifer wells, W23 and W105, were reconstructed in the mid-1980's. They are presently being used as source control wells.
A RAP-required plan for investigating suspected multi-aquifer wells, located in contaminated areas of the Drift-Platteville, which are open to the Prairie du Chien-Jordan, Ironton-Galesville, or Mt. Simon-Hinckley aquifers, was submitted in September 1987. This investigation plan was reviewed in conjunction with the review of the investigation plan for multi-aquifer wells open to the St. Peter aquifer. This plan was submitted by the City in March, 1991. The results of this plan will be used to recommend which leaking multi-aquifer wells, if any, should be abandoned or reconstructed.
When the on-Site buildings were demolished in the early 1970's, visibly contaminated soils were excavated and replaced with clean fill. Excavated soil and demolition debris was moved to the western edge of the Site, covered, and vegetated. The Site was also graded and vegetated with grass.
By 1980, two lined storm water retention ponds had been constructed. One pond is located in the southern portion of the Site and the other is approximately 1,500 feet south of the Site. The ponds are connected by a culvert. Water discharges from the southern pond to a wetland north of Minnehaha Creek. The ponds effectively control surface water run-off from the Site.
The CD-RAP required Reilly to cover, with one foot of clean fill, existing sediments and vegetation in eight portions of the wetland area south of the Site and west of Louisiana Avenue between Walker and Lake streets to protect migratory waterfowl. The filling was completed in 1986; the total area filled was approximately 4.5 acres.
In late 1992, the EPA Superfund Innovative Technology and Evaluation (SITE) team, MPCA and the City of St. Louis Park will take soil borings in a small test area in the southeast corner of the Site. The samples will be tested to see if soil contaminants (primarily PAHs) to see if they can be broken down by naturally-occurring bacteria. If the PAHs are broken down, a pilot study to biovent the contaminated soils will be done. Bioventing involves injecting air into the soil to enhance bacterial growth and their capacity to breakdown the contaminants.
The Office of Health Assessment of ATSDR wrote a Preliminary Health Assessment for the Reilly Tar and Chemical Corporation Site (dated January 31, 1989). The primary documents made available to the MDH for review, and used in the preparation of this Public Health Assessment, are listed below:
Issue Statement regarding the Request for Approval of a Consent Decree with the Reilly Tar & Chemical Corporation and Other Parties, etc. Prepared by the Minnesota Pollution Control Agency's Solid and Hazardous Waste Division, Site Response Section. April 22, 1986.
Record of Decision, Reilly Tar, Minnesota. U.S. Environmental Protection Agency. May 25, 1984.
Assessment of Ground-Water Contamination by Coal-Tar Derivatives, St. Louis Park Area, Minnesota. U.S. Geological Survey. 1984.
Record of Decision, Reilly Tar and Chemical Corporation Site, St. Peter Aquifer, St. Louis Park, Minnesota. U.S. Environmental Protection Agency and the Minnesota Pollution Control Agency. September 28, 1990.
Drift-Platteville Aquifer Northern Area Remedial Investigation Report. ENSR Consulting and Engineering. June 19, 1989.
St. Peter Aquifer Remedial Investigation Report. ENSR Consulting and Engineering. July 21, 1989.
The above documents, additional documents referenced in the body of this document, consultations with MPCA project staff, and site visits form the basis for this Public Health Assessment.
Site visits were conducted by MDH staff on March 14 and April 5, 1991 and May 4, 1992; a joint visit by MDH and MPCA project staff was made on March 20, 1991. A four-lane street (Louisiana Avenue) runs north-south through the eastern portion of the Site. The majority of the Site west of Louisiana Avenue is flat and well vegetated (grass). The on-Site storm water retention pond had a considerable amount of water in it; a number of geese were seen in this pond. Three separate residential developments (rental condominiums and/or apartments) are on-Site; one each in the NW, NE, and eastern portions of the Site (see Figure 2). Signs at the on-Site parking areas designate the portion of the Site west of Louisiana Avenue as a park. There are paved walking paths running through this part of the Site as well as a soccer field (two soccer nets were seen). Children were seen playing in the northern portion of the park (near the rental units) in May, 1992. There are light industrial facilities, businesses, and a restaurant/bar east of Louisiana Avenue. There was no visual evidence of authorized or unauthorized site activities involving soil disruption, construction activities, or on-Site water use in these areas of the Site.
There was debris on the SW portion of the Site which may constitute a potential hazard. On this portion there is an area of high ground that runs from the southwestern edge to the west-central edge of the Site (see Figure 2). This "hill" was created when excavated soil and demolition debris (from the dismantling of the former plant) were piled there in the early 1970's. Erosional gullies were observed on the SW, NW, northern, and east-central faces of the hill. Materials/debris such as rocks, rotted wood, and pieces of bricks, cement and asphalt were sticking out of the soil in these places. Chunks of shiny black, solidified coal tar were also sticking out of a gully on the northern slope. A large tire was also sticking out of the soil on the eastern slope. The top portion of the hill was fairly well vegetated with grass, but still had a number of bare spots. Other portions of the slopes are also fairly well to well vegetated with short grasses. Eleven single-family homes back up directly (at the same elevation) to the hill.
The northern one-half of the western edge of the Site is bordered by Oak Hill Park. Single-family residences and/or apartments either border the Site or are very close to it to the north, west, southwest, and east. There are light industrial facilities and businesses/warehouses south of the Site.
C. Demographics, Land Use, and Natural Resource Use
The Site is located in the city of St. Louis Park (a suburb of the city of Minneapolis) in south-central Hennepin County, Minnesota. The 1988 estimated population of Hennepin County was 989,956 (410,705 households). The 1988 estimated population of St. Louis Park was 43,700 (20,043 households).
There are currently three rental condominium and/or apartment complexes, light industrial facilities, and businesses on the Site. There are also many single and multiple family residences in the immediate vicinity of the Site; some border the Site directly, while others are separated from the Site by a city street. The area within one-half mile (approximate) of the respective borders of the Site is zoned by the city of St. Louis Park as follows:
East: Primarily middle class single-family residences and industrial districts with smaller areas of multiple-family residences and general businesses. A branch of the Hennepin Co. library system, a community center, and the St. Louis Park Senior High school also are within this area.
South: Primarily industrial districts and middle class single-family residences. Methodist Hospital is approximately two-thirds of a mile from the Site in this direction.
West: Primarily middle class single-family residences with smaller areas of residence-business district combinations and multiple-family residences. There is a shopping mall, elementary school, and approximately five park areas, one of which directly abuts the Site, also within this area.
The Site itself is zoned by the City as a planned unit development district.
Minnehaha Creek is approximately 0.5 miles south of the Site. The water level in the creek fluctuates dramatically throughout the year depending on snow melt and rainfall. During periods of high water flow, the portion of the creek in the area of the Site is used for canoeing and occasional wading. The creek is not used for fishing.
As noted earlier, the MDH closed six St. Louis Park municipal wells and one Hopkins municipal well during 1978 - 1980 because of PAH contamination. Because several PAHs are considered to be human carcinogens, the MDH's Division of Disease Prevention and Control compared the cancer incidence rates in St. Louis Park with those of three other areas in 1979 (6). These areas were: the city of Edina which is on the southern border of St. Louis Park, the city of Richfield which is approximately 2-1/2 miles SE of St. Louis Park, and the entire Minneapolis-St. Paul Standard Metropolitan Statistical Area (SMSA) (6). Richfield was selected because of it's similarity to St. Louis Park in a variety of social and economic characteristics; Edina was selected because the PAH contamination was thought to be moving in that direction; and the entire SMSA was used as the major comparison area.
In past years, Minnesota had no systematic method for monitoring cancer occurrence, so cancer incidence rates could not be calculated. As of January 1, 1988, the Minnesota Cancer Surveillance System began collecting data on cancer. This cancer surveillance system is a statewide system which collects information on all pathologically-confirmed cancers that have been diagnosed in Minnesota residents. Since the surveillance system was implemented only a short time ago, there will not be sufficient data for analysis for several more years.
Community complaints regarding contamination of wells and odors from air emissions have dated back to the 1930's. These complaints became more common during the late 1940's and into the 1950's when extensive residential development was taking place in the area. Complaints about problems with soil and surface water contamination and odors continued through the late 1960's (MPCA filed suit against Reilly in 1970).
Between 1978 and 1981, MDH closed six municipal wells in St. Louis Park and one in neighboring Hopkins because of PAH contamination. Because of the documented contamination of part of their drinking water supply, the community expressed concern about potential health effects caused by ingesting these compounds. This concern escalated when the 1979 epidemiological study performed by MDH showed the age-adjusted rates for breast cancer and all cancers combined were significantly higher in St. Louis Park females when compared to females in each of three other study areas.
In recent years, the City of St. Louis Park has received, on average, 2-4 calls per year regarding
the association between ingestion of PAHs and subsequent development of cancer (especially
breast cancer) (7).
