MCES Empire Wastewater Treatment Plant

The Empire Wastewater Treatment Plant green roof was constructed during 2006-2007 as part of a major plant expansion. The plant is located adjacent to the Vermillion River, a designated trout stream. The Metropolitan Council designed the plant's stormwater management practices to both protect the river and trout habitat as well as to serve as demonstrations of innovative stormwater management. The green roof covers a portion of the RAS (reverse activated sludge) pump building. Since the RAS building is partially below grade, the roof is approximately 4-feet high, allowing easy observation of the plants and growing media. During plant establishment the roof was irrigated twice per day using treated effluent water and a sprinkler system with timers.Along with the green roof the stormwater management system includes two large infiltration basins with native plantings, a native plant garden, permeable pavers, and vegetated drainage swales.