Project Update - December 2019. See Project Updates below.
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Metropolitan Council Environmental Services (MCES) began making several improvements in summer 2018 to its Seneca Wastewater Treatment Plant in Eagan. The plant serves the cities of Eagan, Bloomington, Burnsville, and Savage, and small portions of Lakeville, Apple Valley, Inver Grove Heights, and Edina. The plant treats approximately 22 million gallons of wastewater daily.
The improvements, which will be constructed in phases over the next two years, will preserve and renew aging equipment and facilities, increase energy efficiency, and help MCES operate the plant efficiently and cost-effectively into the future. The major components of the improvements are:
- Upgrading the wastewater solids incineration exhaust system to meet new federal air emission limits.
- Replacing solids thickening equipment, along with the related odor control system.
- Replacing the roof and safety railing on the Solids Processing Building.
- Replacing lighting, aeration equipment, boilers, and solids processing equipment to decrease energy use (estimated $200,000 annual energy savings).
- Repairing deteriorated concrete and installing a liner in primary wastewater treatment facilities.
- Reconfiguring a plant building for additional maintenance work areas and equipment storage.
A separate construction project involves installation of the Seneca Community Solar Garden three blocks east of the treatment plant. The solar garden will produce just under 1 megawatt of electricity – the equivalent of powering about 164 homes. Subscribers to the solar garden currently include the cities of Eagan and Burnsville, Dakota County, MCES, and Metro Transit. The solar garden will be installed on 4 acres of a 7-acre site where the Seneca Plant landfilled ash from its solids incinerator from the mid-1970s to the mid-1980s. MCES closed the landfill in 1986 and continues to do post-closure monitoring. MCES will lease the land to solar facility owner Cyprus Creek Renewables. Construction began in late May and should take approximately three to four months to complete.
The Ash Landfill site presents a unique challenge to developers attempting to install solar panels without being able to make any permanent footings into the soil. Two feet underground is a Poly membrane covering the buried ash. Because this membrane cannot be penetrated, all solar panels and electrical conduits must be supported above ground, including the perimeter fence. To accomplish this, concrete platforms or “ballasts” are utilized as structural load-bearing platforms to support all the solar arrays, electrical conduits and fencing that are mounted on top of the membrane.
As of July 27, 2018, the contractor, Hunt Electric, has installed all the ballasts, rack mounts, and most of the solar panels. Work will continue over the next few weeks to complete the solar panel installation and start the electrical interconnection of the modules. Substantial completion of the project is tentatively scheduled for September 14, 2018, with final completion following on October 9, 2018.
For information, please contact:
Tim O'Donnell, MCES Project Citizen Liaison, 651.602.1269 or
Rob Hesse, MCES Construction Contract Administrator, 651.602.8901
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