This document is the case study for Controlling Stormwater Pollutants Wilmington DE Hotel. Retention/detention systems built under the parking lot discussed.

Two underground retention/detention systems were required for a new hotel in Wilmington, where land is at a premium. Therefore, the retention/detention systems were built under the parking lots using 42” (1050 mm) N-12 pipe. To control stormwater runoff pollutants, StormTech Isolator® Rows, constructed of SC-740 chambers and geotextiles, were incorporated into the HDPE pipe runs.

An Isolator Row is designed to capture the first flush of a storm event. The fabric-wrapped chambers provide for sediment settling and filtration as stormwater passes through the filter fabric that envelopes the chamber.

Manholes provide access to the Isolator Rows so maintenance of the Isolator Rows can be done with a high-pressure water nozzle.

Corrugated metal pipe (CMP) was originally specified for the project, but the specification was converted to N-12 because of watertight joints to prevent infiltration of fines,100-year service life and that ADS could provide all materials and components.

The installation was done in August 2013 using 2,530’ (771 m) of 42” (1050 mm) N-12® pipe and 30 SC-740 StormTech® chambers.

Photographs of the project are included.