Watch a recording of the Nov. 28 Reilly site open house
On Nov. 28, 2018, the City of St. Louis Park hosted a presentation about the successful environmental cleanup efforts related to the former 80-acre Reilly Tar & Chemical Corp. (Reilly) site over the past 30 years, as well as plans to continue these efforts for the next 30 years. Watch a recording of the presentation and the Q&A.
View the EPA's Reilly site fact sheet.
From 1917 until 1972, Reilly Industries operated Republic Creosoting Company, a coal tar distillation and creosote wood preserving plant, on an 80-acre site in St. Louis Park. Today, the site near Louisiana Avenue and Walker Street is home to condos and townhouses, a restaurant and bowling alley, an office building, and a recreational park with athletic fields, walking paths, recreation center, pond and playground. The journey from industrial site to its current, usable state was a long and complex one.
From 1917 until 1939, wastes containing coal tar and its distillation byproducts were discharged directly into a ditch that ran the length of the site. These wastes then flowed into a peat bog on the southern portion of the site. An oil-water separator was installed in 1940, but Republic Creosoting Company continued to discharge contaminated waste into the peat bog for the duration of the company's operations at the site.
The soil elsewhere on the site also became contaminated from coal tar and creosote that dripped from leaky pipes, various process materials that spilled during transport and creosote wood preserving chemicals that washed off freshly treated lumber. Historical records suggest there were more than a dozen wells on the site, with depths varying from 50 to more than 900 feet. Over time, creosote and waste materials likely seeped down several of these wells (either directly from the surface or via multi-aquifer transfer) and contaminated the groundwater.
City involvement and ownership
The City of St. Louis Park bought the site from Reilly Industries in 1972. At the time, the state of Minnesota was suing Reilly Industries over pollution discharge issues. The sales agreement included a "hold harmless" clause for soil and water impurities, partially indemnifying Reilly Industries from liability. By this time, creosote and creosote wastes had migrated directly into four underlying aquifers, contaminating the groundwater with polycyclic aromatic hydrocarbons (PAHs). PAHs are a group of chemicals created by the incomplete burning of organic materials like coal, oil, gas and garbage. The contaminants eventually spread to private wells and municipal ground water sources.
After acquiring the site in 1972, the city demolished the Republic Creosoting Company buildings, and over the next decade built residential buildings on the northern end of the site. A major north-south boulevard, Louisiana Avenue, and storm water drainage improvements were also built.
In 1978, the state of Minnesota shut down several public drinking water wells in the vicinity of the site, and the city instituted a water conservation program due to daily shortages of clean, drinkable water. In 1979, 28 multi-aquifer wells were either reconstructed or abandoned to prevent the spread of contamination in ground water. By the time, many community residents had become extremely concerned with the quality of the drinking water.
To understand the cleanup of water at the Reilly site, it’s useful to know the difference between a drinking water well and a source control well.
- Drinking water wells that are part of the Reilly cleanup pump large volumes of water that is treated before use. St. Louis Park drinking water wells are identified by the letters “SLP.”
- Source control wells are used to pump and treat groundwater and control the spread of the contamination and can be identified by the letter “W” before the number. Water from source control wells is treated and discharged into either the sanitary sewer or into Minnehaha Creek - NOT into the drinking water system.
In 1982, the U.S. Environmental Protection Agency (EPA) provided funds to the Minnesota Pollution Control Agency (MPCA) to clean out two contaminated wells. The site was listed on the National Priorities List in 1983. In 1984, a record of decision was issued requiring Reilly Industries, the potentially responsible party, to build a granular-activated carbon (GAC) treatment plant for two existing contaminated municipal wells (SLP 10 and SLP 15) and assist with containing the contaminant plume from reaching other municipal wells by building a source control system in the upper aquifers.
The Reilly plant was demolished in 1972 and the site was leveled. Anecdotal evidence suggests the city brought in topsoil in order to establish grass and the Reilly Site was used as a park as soon as the creosote plant was gone. This early topsoil cover, and subsequent soil cover brought in more recently, was tapered to meet the grade established by a lined storm water pond, by Louisiana Avenue north of Walker Street and by other paved areas at the site.
Based on observations during the 2015 trail construction project, and a visual reconnaissance of the site as a whole, the soil cover is not less than six inches and is more typically one to two feet thick throughout the Reilly site, with the exception of the athletic fields and an area known as “Mount Reilly” (southwest corner of site). View the soil cover map.
- The soil cover placed on the athletic fields in 2002 exceeds three feet in thickness. The fields are equipped with irrigation systems and lighting. The borings excavated for light standards showed three feet or more of soil cover at every location. The fields were constructed to promote drainage for the irrigation systems and provide optimum growing conditions for the field turf.
- The city’s Nov. 14, 1978, Status Report to the MPCA stated that 60,000 cubic yards of soil was relocated to the southwest corner of the Reilly site from northern portions of the site. The relocated soil contained obvious contamination that was not suitable for construction of the condominium building and the mound of relocated soil became known as “Mount Reilly.” Review of a 1982 air photo and topographical map (ERT, 1983) showed a mound about 15 feet high, with an area of about 7500 square yards. The 60,000 cubic yard volume of relocated soil would create an amount approximately six to eight feet high over 7500 square yards; therefore, the 15-foot height in 1982 likely included an appreciable thickness of soil cover. Anecdotal evidence also indicates that routine additions to the soil cover were made to fight erosion. In 2012, a significant addition was made to the northern and northeastern flanks of Mt. Reilly when soil from the St. Louis Park High School football field was brought to the site. This project added more than three feet of fill in some areas; the fill was tapered to meet the existing grade of nearby asphalt walking paths.
The only place on the Reilly site where there is no fill to cover the ground surface that was left after demolition of the creosote plant is the tree-covered mound in the central portion of the site, where the plant office building was located. A stone curb is visible at that location. The city has top-dressed all other portions of the site to establish a vegetative cover.
The private owners of residential properties at the Reilly site weren’t contacted to determine if any additions to the soil cover were made on those properties. If nothing else, the housing added to the extent of impermeable cover at the site.
It’s estimated that approximately 25 acres or 30 percent of the Reilly site is covered by impermeable cover in the form of streets, driveways, parking areas, asphalt paths, buildings and the lined stormwater pond.
(Information provided by Bill Gregg, a professional geologist and a program manager in the St. Paul, Minn., office of Summit Envirosolutions. He has more than 38 years of experience in completing environmental assessment and remediation projects worldwide. Mr. Gregg was the program manager for two Remedial Investigations and Feasibility Studies and related projects at the Reilly Superfund site. He assisted the City of St. Louis Park with the redevelopment and maintenance of portions of the site.)
In 2002, the city built a recreational park to complement the residential housing on the north and south ends of the site. Today, community members enjoy walking trails, a playground, athletic fields, a new park building, and a pond that provides wildlife habitats. The site is now a place where community members can gather to enjoy the amenities the city has worked so hard to create.
Ongoing cost and monitoring
The city invests about $500,000 per year into ensuring the ongoing safety of both the water and the soil at the Reilly site. The city undertook this cost because city leaders wanted to do the right thing and ensure that the site was cleaned up and taken care of properly.
EPA conducts five-year reviews of the site to determine if the remedy for the site still protects people and the environment. The reviews identify issues and recommend how to resolve them. Five five-year reviews have been done so far: in 1996, 2001, 2006, 2011, with the fifth five-year review in 2016 (provided below). Recommended actions have been completed or are in progress, and EPA has determined that the cleanup is still working.
- Water Treatment Plant 4 (SLP4) has been offline since December 2017 due to concerns about volatile organic compounds (VOCs), unrelated to the Reilly site. The agencies and the city agreed to pump an extra 341 million gallons of water from wells SLP10 and/or SLP15 to make up for the loss of pumping at SLP4. That amount is the annual volume of water that the 1986 CD-RAP required to be pumped at well SLP4. See under "Current and recent projects" for more information about Water Treatment Plant 4.
- Fifth Five-Year Review Report for Reilly Tar and Chemical Corp. (St. Louis Park Plant) Superfund Site
Current and recent projects
Any work that involves digging in contaminated areas of the Reilly site must first be approved by the Minnesota Pollution Control Agency (MPCA) and U.S. Environmental Protection Agency (EPA). Work plans must include safe handling of any waste or contaminated soil that’s found and air monitoring to protect workers and nearly residents if waste or contaminated soil is encountered.
At its Dec. 18, 2017, regular meeting, the St. Louis Park City Council authorized execution of a contract with Summit Envirosolutions for 2018 consultant services related to the implementation of the Reilly Tar & Chemical Corporation (Reilly) Consent Decree/Remedial Action Plan (CD/RAP). The services provided under the consultant contract are necessary to ensure the city's compliance with the Reilly Consent Decree. This is an annual contract for the technical services necessary to comply with the sampling, analysis and reporting requirements of the Reilly Consent Decree. The contract also includes assisting the city in negotiating with the agencies (EPA, MPCA and MDH).
Recent progress includes amending the CD-RAP, accepting the use of modern drinking water criteria and switching from groundwater pumping to monitored natural attenuation in the shallow aquifers. Monitoring results compared to the new drinking water criteria show fewer exceedances than in past years. No drinking water wells exceed drinking water standards for any of the chemicals associated with the Reilly site. The city and the MPCA are working with a local laboratory to conduct all water testing required for monitoring the Reilly site; previously samples were shipped priority overnight to an out-of-state laboratory. View the 2017 Annual Monitoring Report.
- Water Treatment Plant 4 (SLP4) is nearing completion and is anticipated to be back in service by fall 2018. The water treatment plant's new configuration represents a milestone in itself, as the PAH treatment (granular activated carbon vessels) associated with the Reilly contaminants were removed because the agencies (EPA, MPCA and MDH) agreed they were no longer needed.
- Comcast has hired MP Nexlevel to install new communication cables to the housing properties on the Reilly site. A construction plan was submitted to the MPCA and EPA in accordance with the CD-RAP. The work is expected to be completed in the fall of 2018.
- In the summer of 2015, a pedestrian bridge and trail were modified at Louisiana Oaks Park along the west side of Louisiana Avenue. Although mitigation of the site was completed many years ago, this new project raised questions among residents and as a result the EPA, MDH, MPCA and the city held a public meeting in November 2015 to address residents’ concerns and answer questions about the site. Documents from this meeting are below.
- EPA fact sheet
- Contact list (updated November 2018)
- Reilly site timeline
In March 2016 the Minnesota Department of Health (MDH) released a report that provides an accurate and complete profile on cancer occurrence among St. Louis Park residents. This detailed study encompasses 20 years of cancer data and firmly establishes that overall cancer incidence and mortality rates in St. Louis Park are virtually identical to cancer rates in the Twin Cities Metro area.
Q: The Minnesota Department of Health (MDH) announced that a review has prompted changes to their water sampling procedures. What effect does that have on St. Louis Park's water sampling results?
A: In its news release, MDH stated, "The concern involves the holding temperature of water samples taken to determine the presence of organic chemicals, such as fertilizers, solvents and common household chemicals. The issue also potentially involves samples taken to determine the presence of inorganic compounds for which holding temperature may be an issue-specifically, cyanide and nitrite (a substance related to but not identical to nitrate).
Levels of nitrate and nitrite in St. Louis Park water are consistently far below acceptable limits so any sampling issues wouldn't affect the water residents drink. Volatile organic compounds (VOCs) are a part of the sampling issue announced by MDH; fortunately, the City of St. Louis Park conducts its own quarterly VOC sampling of its water. Those quarterly samplings were performed correctly with proper holding temperatures by city staff and Minnesota Valley Testing and consistently show VOCs within acceptable limits, so again any sampling issues at MDH wouldn't affect residents' drinking water. It's important to note that the presence of VOCs in the water supply is not unique to St. Louis Park; a few other metro cities also employ treatment methods for VOCs. A September 2015 MDH news release briefly touched on this, and showed another case where St. Louis Park's independent testing was useful in ensuring VOC levels were within acceptable limits. St. Louis Park residents can be assured that when they turn on their tap they are receiving safe water that is carefully monitored and tested. Learn more about MDH water sampling.
Q: Is vapor intrusion a concern at the site?
A: Between 2011 and 2014, EPA conducted an extensive study into possible vapor intrusion from site contamination on properties on and near the site. Vapor intrusion occurs when chemicals, such as volatile organic compounds (VOCs), in groundwater give off dangerous gases that can seep into buildings through foundation cracks and holes, causing unsafe indoor air pollution. EPA and its contractors took samples from indoor air, soil gas beneath the basements and foundations and background soil gas samples off-site. This sampling showed no danger to people from vapor intrusion. Any contamination detected in indoor air was below or within EPA’s acceptable ranges. The Minnesota Department of Health provides information about vapor intrusion.
However, the city has removed these garden beds and is created a raised bed garden. The new gardens are built of cedar (not treated) planks and are 6 inches off the ground with garden soil separated from existing park soil, which means plant roots will not touch the park soil beneath the boxes. A barrier isn't needed with the new gardens since garden soils and park soils won't be in contact, but one was added to suppress weed growth. Soil that is added to the gardens is tested at the University of Minnesota. Vegetables from the garden will be as safe as those grown in any other residential raised bed garden site.
Q: Where can I find all of the documents associated with the Reilly site, including the consent decree?
A: In addition to an information repository housed at St. Louis Park Library, 3240 Library Lane, the EPA also maintains an online administrative record collection. The consent decree is located within the collection, which also includes documents from the EPA, state agencies, the city, local newspapers and many other documents related to the history of the site.
Aquifer: An aquifer is a geological formation capable of yielding a significant amount of water to a drinking water well or spring. Several aquifers are underneath the Reilly Tar site: the Glacial Drift, Platteville, St. Peter, Prairie du Chien/Jordan, Ironton/Galesville and Mt. Simon/Hinkley. [Source: EPA flyer from November 2015 meeting]
Vapor intrusion: Occurs when chemicals such as volatile organic compounds in groundwater give off dangerous gases that can seep into buildings through foundation cracks and holes, causing unsafe indoor air pollution.
VOCs: Volatile organic compounds
For more information about the Reilly site, visit the EPA's website, or visit the St. Louis Park Public Library, 3240 Library Lane, (site files are located here for public use).
Most recent meetings hosted by the city included "Understanding Your Drinking Water" on June 28, 2016, and "Understanding the Reilly Superfund Site" on July 27, 2016.