By Lawrence Berkland, CPESC
Introduction
This project showcases the use of a geosynthetic drainage system as an outfall for a sediment pond, and the accompanying road realignment, both built in Steele County, Minn., in 2006.
In this example, the land usage was primarily agricultural, the watershed approximately 90 acres, and the disturbed area about 5 acres. Because of the realignment of Dane Road and the location of the sediment pond, no additional right-of-way was required (Photo 1).
Why a pond?
Why was a sediment pond constructed in conjunction with the Dane Road realignment?
Assistant Steele County Engineer Larry Berkland explained: “It is a requirement of the Clean Water Act, General Permit Authorization to Discharge Storm Water Associated with Construction Activity under the National Pollutant Discharge Elimination System program (NPDES), which is administered by Minnesota PCA.
“Any time a project disturbs 1 acre or more, this permit is required. The stipulations of the permit are to minimize erosion, collect sediment before leaving the project, and to maintain water quality. In this particular project, the pond was constructed to collect sediment and maintain water quality.”