Marigold Drive Stormwater Improvements

Technical Description:

• CDS^® Hydrodynamic Separator
• Peak Diversion Stormwater Management StormFilter^®

Lake Whatcom supplies drinking water to approximately 100,000 residents in the Bellingham area. Elevated phosphorus levels have caused Lake Whatcom to be placed on Washington State's 303(d) listing as an impaired water body.

The Marigold Drive Project provided water quality improvements by constructing 750 feet of new storm pipe, and a new stormwater treatment system along Marigold Drive to reduce phosphorus and sediment loading of Lake Louise, located upstream from Lake Whatcom.

Wilson Engineering specified a CDS hydrodynamic separator for pretreatment and a Stormwater Management StormFilter to remove Total Suspended Solids (TSS) and phosphorus. The StormFilter with PhosphorSorb has been approved by the WA Dept of Ecology for the removal of TSS and Phosphorus, and has been used multiple times within Whatcom County. The 8' x 11' Peak Diversion StormFilter is equipped with 16 cartridges filled with PhosphoSorb® media and includes a special 48" x 72" hatch for maintenance access.

One of the challenges of this project was the short construction window. State and local regulations mandate construction activities involving excavation are only allowed between May 31 and September 30. Contech worked diligently with the civil engineer, the County, and the contractor to ensure the two systems' were designed, manufactured, and delivered in the construction window. 

Technical Description:

• CDS^® Hydrodynamic Separator
• Peak Diversion Stormwater Management StormFilter^®