Is my drinking water safe?
YES! The drinking water in St. Louis Park is safe. Providing safe drinking water is the most important public duty we as a city have to our residents, and we take that duty very seriously. St. Louis Park's drinking water is regularly tested and must meet the drinking water standards set by the federal Safe Drinking Water Act, a requirement of any public water system. The Minnesota Department of Health (MDH) enforces these drinking water standards for public water supplies in Minnesota. MDH enforcement is based on the regular testing and monitoring of drinking water from public water supplies. Results of this testing are available to each consumer through an annual consumer confidence report which is distributed via mail each year to every household in St. Louis Park. View the city's drinking water reports.
Why is the Highway 100 and County Road 3 Groundwater Plume site proposed for the Superfund program's National Priorities List (NPL)?
In partnership with the cities of St. Louis Park and Edina, the State of Minnesota has agreed to the NPL listing by the EPA because it needs additional resources to investigate and clean up the contaminated area and hold the polluters accountable. The groundwater contamination plume is at a depth of approximately 300 feet below ground and covers an undefined area in St. Louis Park and extending to Edina. The City of St. Louis Park is in full support of this step to ensure those responsible for the contamination are held responsible and to ensure the ongoing health and safety of residents.
The state has dedicated a large amount of funding and staffing to define the area to date; however, much work remains to be done. The amount of resources required to identify the source area, pursue potentially responsible parties and implement a cleanup plan far surpasses the amount of resources received each year by the state's Superfund program.
Resources from the federal government will assist with additional investigation activities and bring in additional technical expertise and specialized legal counsel to effectively address the complexities of the site in a timely manner. If a potentially responsible party(ies) can be identified, cost recovery efforts can be pursued.
EPA's Superfund program focuses on making a visible and lasting difference in communities, ensuring that people can live and work in healthy, vibrant places. The goal is to be an asset to the communities and enhance opportunities for growth and prosperity by deploying federal level resources to the valuable ongoing work started by the local and state governments.
Are there other NPL Superfund sites in Minnesota or across the nation that have groundwater plumes that provided a model for this listing?
Yes. Many of the more than 1,300 sites that have been listed on the NPL include a groundwater contamination plume. Two examples in Minnesota are the New Brighton/Arden Hills Superfund Site (also known as the Twin Cities Army Ammunition Plant or TCAAP Site) and the Baytown Groundwater Contamination site. The TCAAP Site plume extends under several cities, including New Brighton, Arden Hills, Columbia Heights, St. Anthony and Minneapolis. The Baytown Groundwater Contamination plume is approximately 5 miles long, covers about 7 square miles and extends from the eastern portion of the City of Lake Elmo through Baytown Township, West Lakeland Township and the City of Bayport to the St. Croix River.
What are the possible health effects of VOCs?
VOCs are typically described as human carcinogens and can also cause problems with liver and kidney function. The potential for VOCs to be a health concern depends on the toxicity and concentration of the contaminant, the exposure conditions, and the duration or exposure. Factors like age, health condition, gender, and exposure to other chemicals can impact potential health effects for individuals. For more information about VOCs visit this MPCA fact sheet(PDF, 243KB) and this information from the MDH.
What effect does the Highway 100 and County Road 3 Groundwater Plume site have on property values?
We know from past experience with the Reilly site that this is, understandably, of great concern to homeowners. Unfortunately, there's no clear-cut answer to this question. The EPA suggests that concerned property owners should consult a professional who can give a more accurate response to property value questions and concerns. Nevertheless, it is important to note that the impact of the plume is to the groundwater and not to residential properties' surfaces. MPCA maps of the area delineate an estimated plume hundreds of feet below the surface and not surface contamination on residential properties.
What's the difference between the Reilly Tar & Chemical site in St. Louis Park and the Highway 100 and County Road 3 Groundwater Plume site?
These are two different chemical releases that were caused by different sources.
The Reilly Tar & Chemical Corp (Reilly) contamination is mainly creosote, which contains polycyclic aromatic hydrocarbons (PAHs) that were at used in wood treating operations. Contamination at the Reilly site is the result of:
- Wastes discharged directly to a ditch which flowed into a wetland on the southern side of the property.
- Contaminated soil from leaky pipes and various processes that spilled during operations.
- Creosote and waste materials that likely seeped down a Reilly process well located on the property.
The Reilly site has previously been listed on the federal National Priorities List (NPL). The EPA and MPCA, in partnership with the City of St. Louis Park, has been overseeing cleanup there since the late 1970s.
The Highway 100 and County Road 3 Groundwater Plume site contamination consists of volatile organic compounds (VOCs), including tetrachloroethylene (PCE), trichloroethylene (TCE), cis dichloroethylene (DCE) and vinyl chloride (VC), collectively known as chlorinated VOCs. PCE is an industrial solvent used to degrease metals. Under the right conditions, PCE can break down in the environment to form TCE, DCE and VC. MPCA staff have conducted investigations to identify the source of the release, but additional work is needed to complete the investigation.
Is the soil in my yard contaminated?
The proposed NPL listing is for the deep groundwater plume. The deep groundwater plume is at a depth of more than 300 feet. Due to its depth, the deep contamination does not affect the soil on individual properties.
The major concern of the deep groundwater plume is its impact to the cities' municipal wells. To ensure safety of the drinking water, both the cities of St. Louis Park and Edina have installed treatment systems to ensure their drinking water meets the requirements of the federal Safe Drinking Water Act and the state's drinking water guidance values. Once the site is placed on the EPA's National Priorities List, the EPA and MPCA will continue working to identify sources of the deep groundwater contamination plume.
Does this mean that the volatile organic compounds (VOCs) are affecting a larger area than initially identified in 2008?
According to the Minnesota Pollution Control Agency (MPCA), the 2008 vapor study was conducted to evaluate whether or not shallow (e.g., less than 100 feet underground) groundwater concentrations of tetrachloroethylene (PCE) and trichloroethylene (TCE) were impacting indoor air quality. Deeper groundwater contamination that impacts the municipal wells does not present a risk for vapor intrusion. MPCA conducted additional testing in 2014 and 2015 to verify the extent of the vapor plume; no additional homes or businesses are believed to be impacted by vapor intrusion at this time.
Is a vapor extraction system the same as a vapor mitigation system?
Although the terms vapor extraction system (VES) and vapor mitigation system are often used interchangeably, they are used for different purposes. VES is a technology to remediate contaminated soil by inducing a strong vacuum to remove volatile organic compounds (VOCs). Vapor mitigation systems are similar to radon systems. Air flow is induced just under the concrete slab floor in a basement or other lower level and discharges the air above the building. This gives the VOCs a preferential pathway outside so they do not accumulate inside homes or businesses.