Peck Elementary & Early Childhood Center

Peck Elementary and Early Childhood Center was the first new school built in Centerline, Michigan, in nearly 50 years. Since the new school will have more than 15,000 square feet of impervious surfaces, local regulations call for retention/infiltration of the first flush and 100-year storm event. The new facility is located in the area of an old athletic track.

Engineers designed an underground stormwater detention system using 1,063 feet of 96-inch perforated corrugated metal pipe (CMP). CMP was used based on its storage efficiency and ease of long-term maintenance. The original design included two 96-inch header systems. Contech engineers redesigned the two headers to use all end bulkhead fittings, thus shrinking the overall size of the excavation and saving money on fabrication costs. Contech provided complete structural details for the bulkheads and infiltration calculations for detention volumes.

Contech also provided a CDS hydrodynamic separator to meet Macomb County’s stringent water quality requirements of 43% removal of 110 micron total suspended solids at a first flush volume of three cubic feet per second.

The project was fast-tracked, with Cortis Brothers doing the site work. The site drained toward the front of the building where the detention system was to be located and was inundated with water. This delayed installation until October of 2019. Starting at the site low point allowed the entire site to drain once installation activities occurred. With limited site space, Contech arranged for staged delivery of pipe. The project also required both the building and site work to be completed simultaneously, so coordination was required to maintain access to the site.

Installation took place over four weeks. Excavators were used to dig to the required pipe invert and install the perforated pipe. The joints were connected with two-piece bands, and aggregate backfill placed using a small dozer. Once sufficient stone cover occurred and compacted, MDOT Class II sand was placed over the top of the system to subgrade elevations.

The underground stormwater detention system provided by Contech was easy to install as all of the pieces were matched marked for diameter control and matched the shop drawings. The system header was installed first and worked out from one end of the system to the other.

“We like working with Contech as they know what they are doing,” said Scott Vernier, Project Superintendent for Cortis Brothers. “Making sure the system was backfilled and installed correctly is a nice feature, so you know you’re doing it right. We were very pleased with the final outcome of the project.”