FMR's Empire restoration featured by Met Council

FMR's August 2008 Special Places Tour brought 27 local residents and FMR members to view two exciting projects that are improving water quality and habitat in the Vermillion Watershed.

The event, FMR's Empire Plant & Plants tour held on August 9th, showed-off the Metropolitan Council's Empire Wastewater Treatment Plant & wet meadow restoration.

The Plant

The Metropolitan Council's Empire Wastewater Treatment Plant sits on more than 400 acres of land on the Vermillion River in Farmington. This 12 million gallons-per-day capacity facility was recently upgraded to become a demonstration site for Low Impact Development (LID) practices.

Traditionally, stormwater runoff is piped from streets and parking lots to nearby retention ponds or directly to nearby streams and rivers. The runoff carries pollutants like motor oil, fertilizers, grass clippings, eroded soil from construction sites, sand, salt, animal wastes, and more, all of which degrade water quality.

LID projects are designed to cause water flow to mimic natural pre-development conditions and allow stormwater to soak into the ground at or near where it falls. Our event participants toured many of the LID practices installed at Empire, including:

• Multiple rain gardens and bio-filtration basins, where stormwater can collect and infiltrate into the soil. The basins are planted with native prairie species that help remove pollutants and increase infiltration.
• Pervious pavers, which are used as an alternative to asphalt. Pervious pavers have a long life span and allow water to soak through the surface, reducing stormwater runoff.
• Multiple bio-swales, which convey stormwater throughout the site through grassy swales rather than through pipes. These swales allow some stormwater to soak into the ground before it reaches other water treatment practices.
• Green roofs. Planted with native plants including sedums, grasses, and sedges, the green roof not only captures stormwater that would otherwise drain away, but also triples the life span of the roof.

A special note on LID: In 2006, FMR, in partnership with the Minnesota Department of Natural Resources, the Minnesota Pollution Control Agency and others, commissioned a study of LID. The study showed that LID is not only better for the environment, but results in a higher profit for the developer, higher property values and a higher tax base for local government. That study, a finalist for the 2006 Minnesota Environmental Initiative Awards, is available on FMR's website at: http://www.fmr.org/projects/lakeville_lid_study

The Plants

Following the wastewater treatment plant tour, participants moved on to the 50-acre wet meadow restoration on north side of the sewage treatment plant property.

FMR began restoration work on the wet meadow, a critical habitat for migratory shorebirds and a host of other species, in fall 2003. This early work included hydrological modifications and native seeding. The site was re-seeded in 2005 with a native wet meadow mix. In spring 2006, Vermillion Stewards volunteers installed 1,400 potted wetland plants to re-vegetate areas where weeds had been eradicated.

Monitoring and maintenance of the site has continued for several years while native vegetation is established. The entire seeded area was burned for the first time in 2006, and crews have done intensive weed control for thistles, ragweed, sweet clover, purple loosestrife, reed canary grass, and others.

To learn more about FMR's work at Empire, visit our Empire Wastewater Treatment Plant project page.

More on the project is available in Met Council's online version of the August 2008 newsletter, which highlights FMR's work, including photos from FMR's July Empire Plant & Plants Special Places Tour.