Site update
In 2017, the Minnesota Legislature provided the MPCA with $11.35 million to clean up the hazardous waste pit at the Waste Disposal Engineering (WDE) Landfill in Anoka County. Initial design of the cleanup project was completed earlier this year with money provided by the Legislature in 2016. The MPCA now needs to solicit public comments on this cleanup plan and select a contractor to perform the work.
The MPCA hopes to begin cleanup work at the landfill in the fall of 2018.
Site history
The WDE in Andover, Anoka County, is unique in Minnesota — it is the only mixed municipal solid waste landfill in the state that was ever permitted for disposing of hazardous waste. Systems are in place to control contamination leaking from the barrels that were dumped there, but these systems are expensive to operate and do not clean up the actual source of the pollution. Now, the MPCA thinks it’s time to remove this waste and dispose of it properly.
The landfill originally opened as the Grow Township dump in 1962. In 1971, the MPCA permitted the site as a mixed municipal solid waste landfill.
Starting in November 1972, hazardous waste was accepted for disposal in a pit separate from the rest of the landfill. The pit was about a third of an acre in size and lined with 18 inches of clay topped off with 6 inches of asphalt.
Management of the hazardous waste pit was generally poor. An early inspection of the area noted that some barrels had been opened and their contents spilled on the ground. In addition, a truck entering the area had broken through the asphalt liner.
When the pit was closed in January 1974, an estimated 6,600 barrels of hazardous waste had been disposed of in it.
The WDE Landfill stopped accepting any sort of waste in 1983. In 1986, a group tried to study what was in the pit, but the study was cut short because of concerns for worker safety.
During the last 30 years, a number of systems were installed to control pollution at the landfill, which is now largely surrounded by residential areas. From 1992 through 1998, systems were built to keep groundwater contamination and landfill gases from migrating off site. These systems treat 25 million gallons of groundwater and burn off about a million pounds of methane per year.
But in 2011, polychlorinated biphenyls (PCBs) were discovered leaking from the hazardous waste pit. MPCA staff began studying ways to address the problem. A separate system was installed to treat PCB contamination in groundwater from underneath the pit. And in 2013, a vapor extraction system was installed above the pit to collect volatile organic compounds, making the site safer and to allow for possibly digging up the pit in the future.
Aerial view of the WDE Landfill
Despite the measures being taken to address pollution at the landfill, risks remain high, particularly should the systems addressing the hazardous waste pit fail. It is also expensive to operate the systems — since 1995 when the site entered the Closed Landfill Program, $13.7 million has been spent to construct, operate and maintain these systems. In the past year alone, operation and maintenance costs were more than $500,000.
The MPCA has received a total of $12 million to investigate this part of the old landfill, design a cleanup plan and hire a contractor to perform the work. The agency also proposes to move some wastes from along the boundary of the site into the hole left from the pit excavation, and install a new cover that meets current standards to these disturbed areas.
The risk of exposing nearby residents to unacceptable levels of vapors precluded this work from being considered earlier. The vapor extraction system in the hazardous waste pit has lessened this risk. Removal of the hazardous wastes now would both reduce the risk from that source to nearby residents and be more cost-effective than continuing to operate separate remediation systems for the pit.
Frequently asked questions about the project
No, the MPCA will not be testing private drinking water wells as part of this project. Anoka County does have a well water testing program. For more details, visit their Environmental Services webpage.
The Minn. Department of Health (MDH) stores information about many private wells in its Minnesota Well Index. If you are unable to access information about your well through this application, you can call 651-201-4600, 800-383-9808, or email health.minnesotawellindex@state.mn.us for assistance.
Anoka County may have additional information about your well. Contact their Environmental Health Services Department at 763-324-4260 for more information.
You can also hire a private well driller to help you determine your well’s depth. A list of certified well drillers is available on the MDH Licensed/Registered Well and Boring Well Contractor Directory webpage.
The MPCA has been testing the water quality of Coon Creek for 30 years, and currently does not detect pollutants associated with the landfill or the hazardous waste pit in the creek. A series of groundwater extraction wells located between the landfill and the creek keep pollutants from reaching it.
In general, Coon Creek is safe for boating and swimming, but it is polluted with contaminants that are frequently found in urban rivers and streams. Learn more on the MPCA’s Coon Creek Watershed District webpage.
You can also look at raw water quality data using the agency’s surface water data application.
Recordkeeping at the landfill was generally poor, so we don’t know exactly what types of wastes may have been disposed of in the hazardous waste pit. But records do show that chemicals such as paint sludge, paint strippers, degreasers and petroleum solvents were disposed of in the pit.
An accurate estimate of how long this project will take won’t be available until after additional investigation at the site is complete. Recent work at the hazardous waste pit has found more contaminated soil underneath the hazardous waste pit than initially thought. The MPCA is in the process of determining the extent of this contamination.
The work schedule for the project will be decided on as part of the contract with the company hired to do the cleanup work. However, we do not expect that the contractor will work anything other than a normal 5-day work week.
Contacts
Pat Hanson
651-757-2409
pat.hanson@state.mn.us