Atlanta — Oldcastle Precast announced the BioMod Modular Bioretention System received equivalency approval from the Washington State Department of Ecology as a stormwater bioretention planter or planter box.
By granting the BioMod “functional equivalency,” Ecology has formally recognized that Oldcastle’s precast bioretention system does not need to go through the Technology Assessment Protocol – Ecology (TAPE) program for approval, and may be designed using the same standards and criteria as any non-proprietary bioretention planter or planter box. Designers can work directly with Oldcastle Precast to include the BioMod system on project plans to meet Ecology’s or any other agency’s requirements for bioretention in a complete and pre-assembled precast system.
The BioMod system is a conventional, vegetated bioretention system designed as a series of modular precast concrete sections which are filled with layers of mulch, bioretention media, and drain rock. Standard components include both trench and end modules as well as modules for various inlet configurations, pretreatment, and high-flow bypass. The number and size of the modules, as well as the overall configuration of each system, is determined on a site-specific basis. In addition, the BioMod system can be configured as a stand-alone planter box consisting of a single concrete module.
Trench modules can be provided with open bottoms to promote infiltration onsite or with closed bottoms and underdrains to connect to downstream storm drains. The BioMod system typically incorporates non-proprietary, low flow rate media with media components and thicknesses specified by the local regulatory agency. A wide variety of plants or trees may be used in the BioMod system. Plantings appropriate for the local area are typically specified by the designer.
“Now that the BioMod system has received a functional equivalency approval from Ecology as a bioretention system, designers will have a precast, prefabricated, modular option for stormwater bioretention,” said Joanna Ogintz, Oldcastle Regulatory Engineer. “Designers and engineers can easily follow an agency’s standard bioretention design guidance to design a BioMod system to meet the stormwater treatment requirements for their site. With the BioMod system, Oldcastle Precast can provide the most cost-effective, complete stormwater bioretention system available on the market.”