DEM adds three exclusive stormwater treatment devices to approved list for pretreatment

PROVIDENCE – The Rhode Island Department of Environmental Management (DEM) announces that it has added three other exclusive stormwater treatment devices to its approved list for pretreatment: the Jellyfish Filter, the Stormceptor and the Cascade Separator. The Jellyfish Filter has been recertified as a Water Quality Management (BMP) Best Practice while the Stormceptor and Cascade Separator have been recertified for use as a pre-treatment device in Rhode Island.

“Increased development in the Narragansett Bay watershed has made stormwater runoff the biggest source of pollution to our coastal waters,” said Terry Gray, acting director of DEM. “Cleaner beaches and shellfish beds start with better stormwater control in our municipalities. I appreciate the efforts of DEM’s Office of Water Resources to assess and approve essential green infrastructure technology to help alleviate the plague of stormwater.

Precipitation in an urban or suburban area that does not evaporate or seep into the ground, but rather passes through the ground and ends up in the nearest waterway, this is runoff. This runoff contains harmful pollutants such as fertilizers, pet waste, chemical contaminants such as pesticides, fuel leaks, motor oil, garbage, and sediment such as dirt and sand. This mixture of nutrients and contaminants can fuel the growth of harmful algal blooms that reduce oxygen levels and cloud the water, preventing sunlight from reaching underwater vegetation. It can cause beach closures, shell closings and many other water quality issues if left untreated.

The Jellyfish filter uses large area fabric filter cartridges, which can be removed for cleaning, to treat storm water. This is a compact high flow device ideal for urban sites with limited space for stormwater BMPs. Approved models include Offline and Peak Diversion configurations, and re-certification is effective for five years. The Stormceptor is a hydrodynamic separator that uses vortex technology to separate sediment and has space to store captured oil. His recertification is effective for five years. The cascade separator is certified as an approved pre-treatment device which is also effective for five years from October 12, 2021.

The products are sold by Contech Engineered Solutions LLC, which has shown via third-party testing that the Jellyfish filter can remove at least 85% of total suspended solids, 30% of total nitrogen, 50% of total phosphorus, and 60% tsunami pathogens. Contech has also shown via third-party tests that the Stormceptor and Cascade Separator are capable of removing at least 25% of total suspended solids from stormwater runoff. These products are intended for commercial and municipal use.

Proprietary devices approved as a water quality BMP in Rhode Island must be designed to handle the first inch of stormwater runoff produced by impervious surfaces on a site (such as roads, roofs, and roofs). parking lots) during a rainy event. Likewise, pretreatment devices must pretreat the first inch of storm water. Treating the first inch of runoff from impervious surfaces is essential as it can treat about 90% of annual precipitation, ensuring that treatment devices capture the “first draft” of a storm, where most pollutants are found. Approved proprietary devices must also be designed, built and maintained to meet the conditions specified in their technology-specific DEM certification letter.

The review of proprietary applications of stormwater treatment technology is carried out by members of the Stormwater Engineering Program of the DEM Office of Water Resource as well as members of the RI Transportation Department and the RI Management Board. coastal resources. DEM is proud to promote and help advance stormwater treatment technology in the hopes of protecting Rhode Island’s precious water resources by minimizing the environmental impact caused by land use planning. The list of exclusive DEM approved stormwater management technologies and their associated certification letters can be found here. For more information on the DEM Stormwater Technology Review Program, contact Christopher Dill, EIT by email or 401-222-4700 ext. 2777404.

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