• RCE Consultants, Inc.

Optimization Under the California Industrial General Permit

Reduced effort through smart implementation


Effective July 1, 2015, the California General Permit for Storm Water Discharges Associated with Industrial Activities, NPDES No. CAS000001 (IGP), became the governing document for industrial activity related to stormwater runoff. This policy superseded the 97-03 DWQ Industrial General Permit. Two key elements of the IGP relate to effluent and receiving water limitations.


The IGP focuses mainly on implementing Industrial Stormwater Pollution Prevention Plans (SWPPP’s), monitoring of stormwater discharges, and reporting through the California State Waterboard Stormwater Multiple Application & Report Tracking System (SMARTS).


Industrial permittees that have stormwater discharges which are impacted by on site industrial activities, are required to sample and analyze each location where stormwater discharges off site. Sampling and analysis requirements state that industrial dischargers shall collect and analyze a minimum of four storm water samples. These include two qualified storm events occurring between July 1 and December 31 of any given year and two qualified storm events between January 1 and June 30 of any given year. Samples and lab analyses are to be completed for ALL locations where stormwater runoff discharges the site locations as listed in the SWPPP. For industrial dischargers, this means either employing staff to perform the sampling and/or retaining the services of a professional sampling and analysis firm. Either way, greater awareness and resources are required to ensure compliance.


The IGP provides guidance on reducing the frequency and number of sampling locations for dischargers that fall into two categories. Firstly, Industrial dischargers that have demonstrated compliance with pollutant discharge levels for four consecutive sampling events can qualify for a sampling reduction certification. This decreases the number of required sampling events to two as compared to four. Once a discharger continues to demonstrate compliance with pollutant discharge levels, the reduced sampling frequency is maintained. Secondly, industrial dischargers that have sites with substantially similar drainage areas, surface features, and characteristics may complete a Representative Sampling Reduction justification. This is to be submitted to the State Water Resource Control Board for evaluation. Acceptance of this justification, allows a discharger to use fewer samples.


For industrial users that are required to collect samples and perform lab analyses, acquired results act as benchmarks that either keep a project at baseline status or act a catalyst to achieving required targets. For those who are unfamiliar with the level status classifications within the IGP, baseline status only requires sampling and analysis. Status levels 1 and 2 require additional reporting, solution-based action plans and possible installation of remedial infrastructure/solutions.


The current version of the IGP expires on June 30, 2020. The next iteration of the IGP will either maintain or increase the responsibilities of the industrial sector to monitor, treat and prevent the pollution of storm water discharges. Allowable dry weather Total Maximum Daily Loads (TMDL’s) are targeting the impact of bacteria and total nutrient loading on waterways. It is foreseeable that constituents such as this will see incorporation into future Industrial General Permits. Input from a Qualified Industrial Storm Water Practitioner can offer knowledge on how to promote compliance under the current IGP. This input will also be key in minimizing the impact to current operations and preparing stakeholders to meet the requirements of future IGP’s.

6 views
  • Black LinkedIn Icon
  • Black Instagram Icon