2C, Storm Water Ponds Maintenance Program

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municipality's storm water system. Based on the need to start inspections and the history of little maintenance performed, City staff is recommending that dredging and other associated maintenance be programmed into the Capital Improvement Plan (CIP) on an annual basis. The 2010 CIP contains a $50,000 line item for pond maintenance. Since storm water runoff contains many pollutants, it is likely that the City's ponds have sediment build -ups that are polluted with metals and other contaminants. If a pond were proposed to have sediments dredged, the City should perform this maintenance in accordance with the MPCA's "Managing Dredged Materials" guidelines, dated June 2009. A brief summary of the MPCA's guidelines are attached for reference. In accordance with the guidelines, the City would have to determine the level of contamination within the pond sediments. The MPCA has three levels of contamination which are: Level 1 Level 2 Level 3 To determine the level of contamination within pond sediments, the City would hire a consultant to take samples from the bottom of a pond and have them analyzed. As recommended by the MPCA, the number of samples that should be taken depends on the amount of sediment material anticipated to be dredged from a pond. Once the appropriate level of contamination is known, the City can solicit bids from contractors to perform the work. The cost of sediment removal is directly related to its level of contamination. Since pond maintenance would be a new capital expenditure for the City, it is proposed that maintenance be started on the Indian Oaks Court pond because it is small in size, it has easy access to the road, the neighborhood has expressed concerns about pond maintenance, and the Ramsey Conservation District (RCD) has grant money available for the pond's shoreline restoration. The following timeline could be anticipated if the Indian Oaks Court pond were scheduled for maintenance: December 2010 February 2011 May 2011 May /June 2011 Unrestricted reuse of sediments: can be reused in residential areas Restricted reuse of sediments: can be reused in industrial zoned areas Significant contamination: material to be placed in a landfill Receive contractor bids Pond Dredging Restoration and Landscaping Outlet pipe replacement The following estimated costs and financing could be anticipated for the project. Estimated costs include contingencies and engineering. Pond Dredging $32,200 100% City funds Restoration (RCD) $22,000 50% City funds, 50% RCD grant Outlet Pipe 4,800 100% City funds Total Cost $59,000 City Council Meeting P:\Admin \Council\Agendas Packet Information\2010\ 11 -15 -10 Worksession\Packet Information\2C 11-15-10Memo_Pond- Maintenance.doc Page 2 of 3