Congressional District # 06
SOUTH ANDOVER SITEEPA ID# MND980609614
Last Updated: May, 2014
The South Andover site in Andover, Anoka County, Minnesota, was composed of several parcels of land, totaling approximately 50 acres. From 1954 until 1981, the majority of these properties were involved with waste disposal and salvage operations. The site was used to store drums that contained inks and solvents. An estimated three million tires covered the site, and there were two tire fires, one in 1988 and another in 1989. Thousands of barrels of solvents and inks were reportedly burned in open pits on the site. A wetland on the site was used as a disposal area. In addition to transformers, about 200 drums of chemical wastes and about 8,300 gallons of paint, adhesives, and greases in various size containers were stored on the site. Chemical wastes were spilled on the property. Transformers, salvaged electrical equipment, empty drums, and miscellaneous debris were evident on the site. Waste processing stopped in 1977, and waste was not accepted after 1978. In 1980, the state issued notices of violation for improper storage and disposal of chemical wastes.
The site is located 3,000 feet from the Waste Disposal Landfill, another National Priorities List (NPL) site. The area north of the site is a residential neighborhood. Further development has taken place directly to the west and south of the site. The population of the City of Andover was 30,598 at the 2010 census. Residential development was initiated ¼ mile north of the site in the early 1970s, and continued development has occurred to the east, north, and south. Small businesses and new residential developments are now common in the vicinity of and on the site. There are several businesses located on the site, including a department store, a grocery store, a chain drug store, and a small mall. There are several small recreational lakes in the area. The site is generally located within the Coon Creek watershed, which supports an oak savannah plant community.
The U.S. Environmental Protection Agency (EPA) proposed the site for the NPL in December 1982 and finalized the site on the NPL in September 1983.
This site is being addressed through potentially responsible party (PRP) actions with oversight by EPA.
Threats and Contaminants
The health threat of greatest concern to people found during the remedial investigation was the potential to come into direct contact with contaminated soil. This threat has been eliminated with the cleanup and development of the site. Recent groundwater sampling indicates that vinyl chloride is still a contaminant of concern in the groundwater, especially toward the west-southwest. There are also some other volatile organic compounds (VOCs) present in the groundwater, which is being monitored on a regular basis. No one in the impacted area is known to be currently using the groundwater. The installation of new drinking water wells in the impacted area is prohibited by the Andover City Code which covers private wells. The contaminated plume area is entirely subject to the jurisdiction of the code. The City will not issue a Certificate of Occupancy allowing occupancy of a home or building unless it is connected to the available municipal water supply.
EPA conducted a remedial investigation and a feasibility study (RI/FS) focused on groundwater contamination and issued a Record of Decision (ROD) on March 30, 1988. The ROD called for an active groundwater cleanup program. However, based on the results of subsequent groundwater investigations, EPA issued a ROD Amendment on June 9, 1992. The ROD Amendment removed the requirement for groundwater extraction and treatment and required continued monitoring of groundwater, the abandonment of some wells, and resampling of wells if established action levels were exceeded.
A second RI/FS focused on the contaminated soils was completed on December 19, 1991. EPA issued a ROD on December 24, 1991, selecting excavation and biotreatment for some of the soils. During remedial design, the potentially responsible parties (PRPs) discovered that there was significantly less contaminated soil than had originally been suspected, prompting EPA to reconsider the original remedy decision for on-site soils (Operable Unit 02 (OU2)). In May 1994, EPA issued a ROD Amendment for OU2 which changed the remedy to thermal treatment for some of the soils and off-site disposal of the treated and non-treated soils.
Under a Consent Decree (CD), a number of PRPs agreed to perform remedial design and remedial action (RD/RA) at the site. They also agreed to pay EPA's past costs as well as all future response costs, including oversight costs. All construction was completed, and on November 1, 1994, EPA signed a Preliminary Close Out Report (PCOR) for the site, documenting construction completion.
The groundwater analytical results indicated that vinyl chloride exceeded the maximum contaminant level (MCL). The PRP group conducted a natural attenuation study to ascertain whether or not the vinyl chloride will continue to degrade. Analytical results collected from seven temporary well locations and three monitoring wells provided evidence that intrinsic bioremediation of the chlorinated VOCs was occurring within the upper sand aquifer at the site. In addition, computer modeling suggested that the vinyl chlroride plume would not extend beyond 1,000 feet from the site. A well survey conducted within a one-half-mile radius of a specific downgradient well location did not identify any residential wells within this radius to the south or west. Coon Creek was not within the one-half-mile radius. Thus it was concluded that the attenuation of the vinyl chloride plume within 1,000 feet of the site did not appear to pose an immediate threat to potential human or ecological receptors.
Additional groundwater monitoring has been conducted and a groundwater monitoring program has been established for the site. The groundwater was monitored for the length of time specified in the decision documents, and additional groundwater monitoring that has been performed indicates that the VOC concentrations are generally decreasing.
An institutional control study and a plan have been developed and these found that a governmental control is in place that applies to the contaminated plume area. The Andover City Code contains prohibitions against the installation of wells where municipal water is available. Municipal water is available in the area of concern at the site. All parcels in the plume area were found to be connected to municipal water except for a few that do not contain buildings.
EPA published a notice of intent to delete the soils operable unit (OU2) from the NPL in September 1998. The partial deletion was taken because EPA had determined that the responsible parties had implemented all response actions required and EPA, in consultation with the State of Minnesota, had determined that no further response was appropriate for this particular operable unit. EPA and the State determined that remedial activities conducted at the site to date had been protective of public health, welfare, and the environment. EPA announced the deletion of OU2 of the site from the NPL on October 28, 1998. This did not delete the groundwater operable unit (OU1). In the August 18, 2006, Federal Register, EPA published a technical correction concerning the partial deletion. In late 1997, the City of Andover completed its acquisition of parcels at the site for the purpose of redeveloping the area as a light industrial/commercial zone.
EPA completed the Third Five-Year Review (FYR) for the site on June 7, 2011. The FYR found that the remedy was constructed and was monitored in accordance with the two ROD Amendments. Groundwater monitoring that is more comprehsive than that required in the decision documents has been performed to track the contaminated groundater plume. The groundwater sampling data do not show an indoor air vapor intrusion pathway present, despite VOCs present in the groundwater. The restrictions on installing wells within the City of Andover prevent future exposure to the small contaminated groundwater plume that still exists. For the soil (OU2), the remedy is considered protective in both the short term and the long term because there is no evidence of current or future exposure. For the groundwater (OU1), the remedy is considered protective in the short term because there is no evidence of current exposure. Long-term protectiveness of the groundwater will be achieved when the groundwater reaches cleanup levels. The next FYR for the site is required by June 2016.
Property ReuseIn late 1997, the City of Andover completed its acquisition of parcels at the site for the purpose of redeveloping the area as a light industrial/commercial zone. The site and some adjoining property that also had to be cleaned up now contain a number of commercial establishments (comprising Andover Station) and townhomes.
ContactsRemedial Project Manager, U.S. EPA
linda kern (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesPUMPKIN CITY INVESTMENTS
HIDELBERGER CECIL PROPERTY
SOUTH ANDOVER SITES
HIDELBERGER CECIL MUSKET RANCH