Location: Marietta, GA
Application: Stormwater Detention and Treatment
Product Used: 9′-0” DoubleTrap & SiteSaver
Total Water Stored: 28,033 CF
Number of Pieces (per basin): 66
Foundation: 6” stone base
Water Quality Flow: 4.32 CFS
Owner: Chattahoochee Technical College
Engineering Firm: Eberly & Associates Inc (Atlanta, GA)
General Contractor: McCarthy (Atlanta, GA)
Installing Contractor: Dennis Taylor & Co (Lawrenceville, GA)
Project Details: Chattahoochee Technical College has recently inaugurated its new Health Science building at the Marietta Campus. The project involved the construction of a new building, that allows the college to increase student enrollment in health programs, as well as several hardscape and landscape improvements.
Challenges: The project, however, was not without its challenges. The campus had existing ponds on site to handle stormwater but, due to the redevelopment and increase of impervious area, additional storage was needed to meet the Cobb County Stormwater Regulations for volume control and water quality. There was not sufficient space available for an additional above-ground pond and there were many existing underground utilities on site. Philemon Bannis, P.E., Project Engineer at Eberly and Associates Inc., explained, “The site had underground utilities and stormwater management had to be provided in a developed area.” In addition to these challenges, a BMP was needed to meet stormwater regulations and also augment the existing water quality ponds on site.
Solution: Eberly and Associates Inc. partnered with StormTrap to provide a solution for the site’s stormwater issues. A 9’-0” DoubleTrap system (66 pieces) was designed to fit in the small footprint under the Health Science building parking lot. The detention system provided the total storage needed of 28,033 cf. As an additional BMP measure, a SiteSaver hydrodynamic separator was installed upstream of the detention system to treat runoff from the site and meet water quality requirements. The SiteSaver device collects trash, sediment, and hydrocarbons from stormwater before they are discharged into the detention basin and waterways.
The project engineer affirmed that StormTrap was chosen over other products because of the system’s flexible design that easily accommodated existing utilities. In addition, StormTrap personnel was very “professional and responsive,” stated Bannis.