Baytown Township Groundwater Contamination Site
This page provides information about cleanup of the Baytown Township Groundwater Contamination Site (Site). More detailed information about this Site can be found in technical reports primarily available from the Minnesota Pollution Control Agency (MPCA). Some Site reports are also available from the Minnesota Department of Health (MDH).
Where is the site?
The Site is located in central Washington County, Minnesota. The Site is defined essentially by the MDH’s Special Well Construction Area (SWCA). The SWCA was enacted to regulate the construction of new wells. At their widest extent, the SWCA and the Site are approximately bounded on the north by 50th Street and on the south by 20th Street. The contamination 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 as shown in the map below.
Map of Site
What and where is the contamination?
The main contaminant of concern that has been released to groundwater at the Site is 1,1,2-trichloroethene (TCE). The TCE plume is located within the Site and is approximately five miles long and covers about seven square miles. The TCE plume affects four major groundwater aquifers. The TCE plume for the unconsolidated and Prairie du Chien aquifers is shown above. The TCE plume for the Jordan Aquifer can be viewed in the Jordan plume map (c-s3-12a).
The TCE plume for the deepest aquifer, the Tunnel City Aquifer, can be viewed in the Tunnel City plume map (c-s3-12c). Approximately 400 homes and several businesses located within the TCE plume are served by private wells.
What does the remedy include?
The MPCA selected a remedial action, or cleanup, for releases at the Site that will protect the public health and welfare and the environment. The remedial action was set forth in the July 2007 Record of Decision (ROD) Amendment. The major operable unit components of the selected remedy include the following:
- Operable Unit 1 (OU1) — Continued monitoring of private wells, sampling of private water supply wells, and installation, change out, and maintenance of granular activated carbon (GAC) filter systems as previously designated in the original May 2000 ROD.
- Operable Unit 2 (OU2) — An air stripping treatment system at Bayport Municipal Well #2. The city of Bayport is responsible for ongoing operation and maintenance of this air stripper.
- Operable Unit 3 (OU3) — Containment of TCE in groundwater at the primary source zone — a former metal fabricating shop located at 11325 Stillwater Boulevard in Lake Elmo.
- In early March 2008, the MPCA completed construction on a hydraulic barrier to contain the TCE plume and prevent off-property migration of contaminated groundwater. The barrier consists of four extraction wells spaced so their influence overlaps and collectively captures the contamination before it can migrate off the property. The extracted water is then treated by air stripping to remove the TCE from the water.
The pumps for the barrier system were started up on March 17, 2008. This barrier is operating continuously at approximately 70 gallons per minute with the exception of down time for maintenance or tests. Its purpose is to control the groundwater gradient so that high concentrations of contamination are unable to continue to migrate to the east. The barrier likely will operate for more than 10 years.
The four extraction wells recover the groundwater and pump it to a low-profile air stripper located within a treatment building. The air stripper removes more than 99 percent of TCE from the incoming water. The water is treated to less than 1 microgram per liter (µg/L) which is below the MDH Health Risk Limit of 5 µg/L. The water is then discharged back to the soil using horizontal wells approximately 25 feet underground.
- In early March 2008, the MPCA completed construction on a hydraulic barrier to contain the TCE plume and prevent off-property migration of contaminated groundwater. The barrier consists of four extraction wells spaced so their influence overlaps and collectively captures the contamination before it can migrate off the property. The extracted water is then treated by air stripping to remove the TCE from the water.
Potential vapor intrusion risk
In November 2008, the MPCA conducted an intial screening for potential TCE vapor intrusion related to the Baytown Site. The following document provides an update:
Granular activated carbon filters
The MPCA has installed whole-house GAC filters in a number of residences near the Baytown site to ensure safe drinking water. This fact sheet gives general information on their use and maintenance.
-
Granular Activated Carbon Filters (c-s1-05)
Where can I get more information?
All documents prepared during the investigation, selection, design and construction of the remedy are available for review at the MPCA, 520 Lafayette Road N., St. Paul, Minn.
Selected documents are also available for review at the Bayport Public Library, 582 N. Fourth Street, Bayport, and the Rosalie E. Wahl Library, 3479 Lake Elmo Ave. N., Lake Elmo.
Testing your groundwater
Information about testing your groundwater is available on the Minnesota Department of Health's Web site. 
Staff contacts
- Kurt Schroeder, Hydrogeologist, 651-757-2703, kurt.schroeder@state.mn.us
- Sam Brungardt, Public Information, 651-757-2249, sam.brungardt@state.mn.us
- Minnesota Department of Health: Health issues — Emily Hansen, 651-201-4602. Well issues — Virginia Yingling, 651-201-4930.
