Burnt Mill Creek Watershed Study and Kerr Avenue Water Quality Treatment Wetland

Client: NC DENR, Ecosystem Enhancement Program

Location: Wilmington, North Carolina

Services: Watershed analysis site assessment mitigation planning, agency coordination, permitting, design plan and construction document preparation, and construction

Following the development of a watershed analysis for the Burnt Mill Creek Watershed in New Hanover County, North Carolina, KCI was selected to provide turn-key design build services for a ¾ constructed wetland for stormwater BMP. Goals of the project included; Treatment of first flush discharges in the contributing drainage area, Wildlife habitat, Watershed stakeholder education.

The site receives drainage from approximately 240 acres of urbanized development through a closed drainage network whose terminus was 120’ above the site. Detailed evaluations where conducted to establish the hydrology and hydraulics for the first flush, 2, 10 and 100 year storm events. Pollutant loadings were determined through the application of Schuler’s simple method and verified through chemical analysis of first flush. Based on these analyses, a design was developed to capture the first flush in a forebay for treatment and pass higher flows through a bypass channel. The forebay utilized a series of 6” PVC pipes to control the rate of flow into a treatment area. The treatment area provided water depths ranging from 1” to 12” arranged in a serpentine pattern to increase contact with planted material and maximize time of residence. The site was revegetated with 20 species of wetland plants to improve habitat diversity.

Upon completion of the final design, KCI obtained permits and initiated the construction of the project through its subsidiary construction company KCI Environmental Technologies and Construction Inc.

Construction was overseen by the designer, allowing field modifications for several un-mapped utilities and soil conditions.

During construction, KCI assisted with the development of a documentary by the local cable network on the project, including interviews, local stakeholder coordination, and “adoption” of the site by the local chapter of the Cape Fear River Watch. Subsequent monitoring of the site has verified the sites effectiveness in removing, phosphorous, nitrogen, oil and grease, and increasing dissolved oxygen.




© KCI Holdings 1994-2006