Congressional District # 07
ASHLAND/NORTHERN STATES POWER LAKEFRONTEPA ID# WISFN0507952
Last Updated: May, 2015
The Ashland/Northern States Power Company (NSP) Lakefront site is located in Ashland, Wisconsin. The site is bordered by US Highway 2 to the south, Prentice Avenue to the east, Ellis Avenue to the west, and Chequamegon Bay to the north. The properties on which contamination is located encompass approximately 12 acres and include NSP (now known as Xcel Energy), Wisconsin Central Limited Railroad corridor, the city of Ashland's old wastewater treatment plant/Kreher Park, and contaminated sediments in Chequamegon Bay, an inlet of Lake Superior.
The site area is mixed residential and recreational. Ashland's population is approximately 8,795 people. Kreher Park includes a lakefront bicycle path. Along the eastern boundary of Kreher Park is a boat ramp, a public swimming beach, and a campground. The Ashland marina is connected to the northwestern portion of Kreher Park. The filling of Chequamegon Bay after 1880 created much of the land that is the current site. Landfilling material included sawdust and other wood waste products from former lumber mills as well as various demolition and fill material, derived from a former manufactured gas plant (MGP) on Xcel Energy's current property.
Site ResponsibilityThis site is being addressed through federal, state, and potentially responsible party (PRP) actions.
Threats and Contaminants
The landfill and former MGP activities are likely the primary cause of site contamination. The subsurface soil, groundwater, lake sediments and surface water are contaminated by varying concentrations of complex mixtures of organic chemicals known as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). When PAHs are encountered in high concentrations, they're not very soluble in water and appear as coal tars and oils which are commonly referred to as nonaqueous phase liquids or NAPLs. Some NAPLs are heavier/denser than water (DNAPL) and some are lighter than water (LNAPL).
People aren't currently exposed to the contaminated soil, because the contaminated soil at the site is covered with clean fill.
Chequamegon Bay sediments pose a risk if agitated by wave action, boat anchoring, swimming, and/or wading since the coal tars and LNAPLs are released into the water column and form "slicks" on the water surface. Warning signs and buoys are posted all around the contaminated area to warn people against swimming, wading, and boating and provide instructions for washing and flushing their skin and eyes. Fish sampling in Chequamegon Bay indicates that fish do not contain levels of site-related chemicals that are a health concern. However, people should continue to follow fish consumption advisories for Lake Superior.
While the groundwater at the site is contaminated, the City of Ashland residents are not exposed to it, because the municipal water supply is instead derived from Chequamegon Bay, outside the known extent of surface water contamination. However, some people do use water from wells near the contamination zone. These wells are not yet contaminated, but could become contaminated in the future.
Local officials notified the Wisconsin Department of Natural Resources (WDNR) of contamination found in excavations around the former wastewater treatment plant in the late 1980s. In 1993, WDNR began investigating the contamination found on city property. These investigations concluded that at least some of the contamination came from the former MGP that operated adjacent to the city's property. In 1995, WDNR notified NSP (now known as Xcel Energy), the city of Ashland, and the Wisconsin Central Limited Railroad that they are potentially responsible parties (PRPs) for the contamination. WDNR and Xcel Energy have carried out various investigations on the properties.
In 1999, a citizen's petition requested that the U.S. Environmental Protection Agency (EPA) assess the site and determine if it could be listed on the National Priorities List (NPL). Based on its hazard ranking score, EPA proposed listing the site in December 2000. The site was added to the NPL in September 2002. EPA signed an administrative order on consent (AOC) with Xcel Energy on November 14, 2003, to complete an investigation of the site, called a Superfund Remedial Investigation and Feasibility Study (RI/FS). Previous investigatory work was used to streamline the RI/FS.
Xcel Energy started the RI sampling in April of 2005 and subsequently developed and submitted an RI Report and an FS Report. EPA approved the RI Report in October 2007 and the FS Report in December 2008. In addition, Xcel Energy conducted an innovative technology study at the site in the deep aquifer through the EPA SITE program. This site demo was completed in summer 2007.
Since fall 2000, Xcel Energy has been implementing an interim cleanup action which removes (pumps out) coal tar from the groundwater beneath its property, separates it from the water, and allows it to be transported offsite for proper disposal. In May 2002, Xcel Energy implemented a second interim response to eliminate a coal tar seep in Kreher Park.
In November 2008, EPA presented the site to EPA's National Remedy Review Board because, based on information in the FS Report, the estimated cost of the cleanup was expected to exceed $25 million. Following completion of the National Remedy Review Board process, in June 2009 EPA issued a proposed cleanup plan for public review and comment. EPA held a public hearing regarding the proposed cleanup plan on June 29, 2009. After considering all public comments, EPA issued a record of decision (ROD) on September 30, 2010, documenting the selected cleanup plan for the site. The Wisconsin Department of Natural Resources concurred with the ROD.
The selected remedy specified in the ROD will serve as the final cleanup action for the site and is estimated to cost between $83-$97 million. The selected remedy consists of the following key components:
• removal and treatment or off-site disposal of contaminated soil, groundwater and sediment, including all NAPL;
• engineered surface and vertical barriers to contain contaminated groundwater;
• groundwater extraction for hydraulic control and restoration, with possible in-situ treatment of groundwater;
• long-term groundwater and sediment monitoring; and
• institutional controls to limit future site use to prevent exposure to hazardous substances that will remain at the site after construction of the remedy is complete.
The United States and the State of Wisconsin began negotiating with the PRPs in April 2011 for the design and implementation of the site remedy. EPA and the State decided to split the negotiations into two phases: the on-land portions of the site remedy first, followed later by negotiations for the sediment portion of the remedy. The consent decree for the on-land portions of the remedy was enter with the court in October 2012, and EPA is currently reviewing the remedial design documents for the on-land remedies. The consent decree also settled all federal, state and tribal natural resource damage claims. EPA had a kick-off meeting on May 16, 2013, with the PRPs to discuss negotiations for the sediment portion of the remedy.
In addition, EPA, WDNR, and XCel Energy entered into an Administrative Order on Consent (AOC) on July 31, 2013, requiring XCel Energy to perform offshore sampling. The offshore sampling work was conducted in the fall of 2013 and will help EPA determine if the selected sediment remedy can be safely implemented.
A Consent Decree was signed in October 2013 for RD/RA of Phase I remedy. The Phase I remedy implementation started in May 2014. The majority of Phase I remedy was completed in February 2015, but the remaining tasks will be completed in 2015.
In addition, an AOC was entered by EPA, WDNR and Xcel to complete a pilot test study for wet-dredge. The pilot test is planned for 2016.
ContactsRemedial Project Manager, U.S. EPA
scott hansen (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesASHLAND FLASH NSP LAKEFRONT SITE
NORTHERN STATES POWER
ASHLAND/NSP LAKEFRONT SITE