Orange County Branch Newsletter

April 2015

Sustainability Committee

Green Infrastructure and California's new Industrial General Permit

By: Michael Dole, PE, M.ASCE | Conestoga-Rovers and Associates a GHD company

On April 1, 2014 the State Water Resources Control Board (SWRCB) approved the new National Pollutant Discharge Elimination System (NPDES) General Permit for Storm Water Discharges Associated with Industrial Activities (Order 2014-0057-DWQ No. CAS000001); it will become effective July 1, 2015.  This new Industrial General Permit supersedes the previous Permit (Order 97-03-DWQ) which was adopted in 1997 and has been industry practice for over 17-years.  All industrial facilities that were covered under the previous permit must update their Storm Water Pollution Prevention Plans (SWPPPs) and comply with the new regulations.

While there are a number of relatively significant changes between the two permits, including the number of facilities that must comply with requirements, one major change is the inclusion of Advanced Best Management Practices (BMPs), for which all hydrologic calculations shall be certified by a California licensed professional engineer.  Advanced BMPs are generally structural BMPs that must be implemented if minimum BMPs (e.g., housekeeping) are inadequate to achieve compliance with the technology-based effluent limitations. Examples of advanced BMPs include: exposure minimization BMPs (e.g., storm resistant shelters), storm water containment and discharge reduction BMPs (e.g., detention basins), treatment control BMPs (vegetated swales), and other advanced BMPs.

This new Industrial General Permit provides an opportunity for the engineering community to recommend the investigation and implementation of “green” infrastructure at industrial facilities.  Following proper pre-treatment, “green” strategies and structures can be constructed to facilitate the infiltration of clean stormwater runoff.  This move from the traditional “grey” infrastructure to “green” infrastructure on industrial properties consisting of close to 100-percent imperviousness is seen as a potentially large step towards regional sustainability of our limited water resources.

For more questions about the new Industrial General Permit or about green infrastructure, please reach out to the ASCE OC Sustainability committee or visit http://www.asceoc.org/committees/sustainability_committee .