Some 1,700 residents of Spring Park are now enjoying cleaner drinking water thanks to the state’s Superfund Program, administered by the MPCA. Two of the town’s municipal drinking water wells are contaminated with trichloroethylene (TCE) above levels considered safe. Using a combination of state Superfund and legislative bonding dollars, the MPCA recently capped a two-year effort to design and build an addition to Spring Park’s drinking water plant that includes state-of-the-art equipment to remove the TCE.
TCE was first identified in two of Spring Park’s three municipal wells in 2004. At that time, levels of the contaminant were below state drinking water standards. But in 2013, the Minnesota Department of Health changed the TCE standards and the MPCA worked with the city of Spring Park and the MDH to evaluate options for providing clean municipal water to the city’s residents. The best short-term fix was to use the one clean municipal well not impacted by TCE, however this well could not be used as the sole water source indefinitely.
To jumpstart efforts to find a long-term solution to the drinking water contamination, the MPCA created a Spring Park Municipal Wells Superfund site and listed it on the state’s Permanent List of Priorities in 2014. This listing gave the MPCA access to additional funding to perform work at the site.
With this funding, the MPCA hired a contractor to study and determine the best option to address Spring Park’s public water quality. That option was to design and construct an air stripper treatment system as an addition to the city’s current treatment plant.
An air stripper is essentially a series of trays that water runs over while air blows up through it from below. This volatilizes the TCE, which is vented outside. The treatment system design was completed in June of 2015 and construction took about a year, from April 2016 to April 2017. It has been online since April 17 of this year.
Nearly $1.2 million in legislative bonding funds and about $400,000 in state Superfund money was used to evaluate, design and build the new treatment system that allows Spring Park to use all three municipal wells again. The air stripper treats up to 750 gallons of water per minute, and kicks into operation whenever pumps turn on to top off the city’s water tower.
The MPCA started a parallel investigation in 2014 to look at potential sources for the TCE in the municipal wells. The study characterized the geology in the area and sampled the aquifers from which the city draws its drinking water.
Timeline for future work
The National Priorities List is a list of sites identified for long-term cleanup. The EPA will propose listing this site on the NPL in January 2018.
When EPA proposes to add a site to the NPL, the EPA publishes a public notice about its intention in the Federal Register and issues a public notice through the local media to notify the community, so interested members of the community can comment on the proposal. The EPA then responds to comments received.
If, after the formal comment period, the site still qualifies for cleanup under the federal Superfund Program, it is formally listed on the NPL. Once it is listed, the EPA will publish a notice in the Federal Register and respond formally to comments received. This is part of the process to prepare for getting support from the EPA for further investigations into identifying and naming responsible parties for the contamination and cleaning up of the impacted aquifers.
For more information
- Rick Jolley — Hydrogeologist