Metropolitan Council Environmental Services (MCES), operator of the metro-area
wastewater collection and treatment system, is continuing its response to a wastewater spill caused by a hole in one of its regional force main sanitary sewers that occurred on Thursday, June 20, in the City of Chanhassen.
Water quality monitoring:
MCES water quality monitoring results from Friday, June 28, and Monday, July 1, showed continued low bacteria levels at three monitoring sites at the north end of Lake Minnewashta, and staff have removed spill warning signs from the lakeshore. Water quality monitoring the week of June 24 also confirmed that several public areas of the lake were not affected by the spill. Bacteria levels in a stormwater streambed and holding pond just northwest of the lake were below the state water quality standard last week, but were above the standard on July 1, likely from rainfall-driven runoff over the weekend. MCES staff will collect water samples from these sites again today (July 3), and continue water quality monitoring until bacteria levels are consistently below the state water quality standard.
Site restoration:
MCES has an emergency contractor working at the spill site today (July 3) along the south side of Highway 7 west of Arbor Lane. The contractor is removing contaminated soil from a ditch along Highway 7, and placing new topsoil and seed. This should improve the water quality in future rainfall runoff that flows from this ditch into the stormwater streambed and pond northwest of the lake. The contractor also will add gravel and grade the area that was excavated June 21 to access and repair the broken sewer pipe. This will temporarily re-open a segment of bike trail until we can re-pave it in the next several weeks.
For more information, contact Tim O’Donnell, Environmental Services communications, at tim.odonnell@metc.state.mn.us or 651-602-1269.
