The issue of trash as a regulated pollutant in stormwater runoff needs to be considered throughout all agencies having regulatory power over stormwater runoff. An excellent reference source is ASCE Guideline for Monitoring Stormwater Gross Pollutants (January 10, 2007)Presently, most regulatory focus is on sediment removal and nutrients such as nitrogen and phosphorus. These pollutants deserve the regulatory attention, but not to the exclusion of trash.
The Maryland Department of the Environment and the District of Columbia Department of the Environment-Natural Resources Administration submitted to the U.S. Environmental Protection Agency, Region 3, Water Protection Division a Total Maximum Daily Loads of Trash for the Anacostia River Watershed, Montgomery and Prince George's Counties, Maryland and the District of Columbia.(http://www.anacostiariverkeeper.org/)
The photograph shows accumulation of trash on the Hickey Run Creek at the New York Avenue underpass at the National Arboretum. The US Army Corps of Engineers has developed a plan for the capture of 100% of the trash that will be transported during the "first flush". The plan incorporates the use of a Terre Kleen hydrodynamic separator together with an attached trash box into which a flow of 150 cfs will be directed via a wier wall to be constructed from the underpass to the Terre Kleen unit.
Terre Hill Stormwater Systems, working closely with the US Army Corps of Engineers, DDOE, DC Water, USDA and the contractors, Meltech Corp, Inc. and Environmental Design & Construction, LLC designed and engineered a precast concrete structure in substitution for a poured in place design, saving an estimated 5 weeks of construction time.
The Terre Kleen does not require any external by-pass and is constructed in-line, thus, enabling it to capture all trash, debris and non emulsified oil and grease, together with sediment and the nutrients and heavy metals attached to it.
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