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Stormwater Pond Sediments

Project Summary

Stormwater ponds, like the one pictured, are commonly used throughout the metropolitan area to treat stormwater prior to discharging to another surface water. These structures are popular because they are effective in removing suspended materials, provide open space and wildlife habitat, can be aesthetically pleasing, and require little maintenance. However, the sediment which accumulates in the ponds must be periodically removed and disposed of. Although the performance of stormwater ponds, in terms of removing suspended solids and associated constituents, is well documented in available technical publications, there is surprisingly little information available on the characteristics of the sediment. As a result, the Metropolitan Council Environmental Services, with financial assistance from the Minnesota Pollution Control Agency initiated a project to characterize pond sediments in June of 2004. The links below provide access to the project reports and data files.

Initial Investigation

A literature search was initially conducted to compile available information regarding the quantity and/or quality of the sediments in stormwater ponds.  The findings, as well as information comparing pond sediments to other residuals, are documented in the report below.

• Literature Characterization Report (PDF 2.12M)

Survey

A survey was sent out to each state and Canadian province requesting the current regulations for the use and/or disposal of stormwater pond sediments in each state or province.  The report below summarizes the responses from the states and provinces.

• Survey Report (PDF)

Final Report

Ten stormwater ponds were sampled and approximately 5,000 analyses were conducted.  The final results for this project were compiled and a report was written in June of 2006.  The report, along with a supporting raw data file, are available by clicking on the links below:

• Stormwater Pond Sediment Report (PDF 8.12M)
• Raw Data File (MS Excel 2.2M)

Please contact Bob Polta at bob.polta@metc.state.mn.us or by phone at 651-602-8390 if you have any questions or comments.