Recently Adopted California General Permit for Construction Storm Water Discharges Becomes Effective July 1, 2010

On September 2, 2009, the California State Water Resources Control Board Division of Water Quality adopted Order 2009-0009-DWQ, the National Pollutant Discharge Elimination System (NPDES) General Permit For Storm Water Discharges Associated With Construction and Land Disturbance Activities (General Permit). All discharges of storm water and non-storm water from construction sites are prohibited except those specifically authorized by the General Permit or another National Pollutant Discharge Elimination System (NPDES) permit.

The General Permit applies to a broad range of construction or demolition activities including, but not limited to, clearing, grading, grubbing, excavation, and any other activity that results in a land disturbance of equal to or greater than one acre. It also applies to projects less than one acre if the construction activity is part of a larger common plan, and other construction activities related to particular projects, such as those associated with linear underground/overhead utility lines, oil and gas, agriculture that is considered “industrial,” and others.

The new General Permit becomes effective on July 1, 2010. Existing discharges covered under a previous permit must continue to comply with the previous permit until July 1, 2010, but must electronically file through the State Water Board’s Stormwater Multi-Application and Report Tracking System (SMARTS) website for coverage under the new General Permit. Existing discharges will be permitted under Risk Level 1 (see below), with certain exceptions where the Regional Water Board may require a discharger to recalculate the site’s risk level.

Dischargers must electronically file Permit Registration Documents (PRDs) prior to the construction project activity. PRDs must consist of:

  • a Notice of Intent;
  • a Risk Assessment;
  • a Site Map;
  • a Storm Water Pollution Prevention Plan (see below);
  • an Annual Fee payment; and
  • a Signed Certification Statement.

The General Permit categorizes sites into three “Risk Levels.” To determine their project’s Risk Level, dischargers must calculate (1) the project sediment risk, and (2) the receiving water risk pursuant to, among other items, factors identified in Appendix 1 and Attachments C, D, and E of the General Permit. The resulting calculated Risk Level then triggers certain requirements. A discharger’s obligations to comply with various requirements included in the General Permit depend on the Risk Level of the discharger’s site. For example, Risk Level 2 and 3 sites must conduct effluent monitoring for pH and turbidity according to the General Permit’s numeric action levels (NALs), while Risk Level 3 sites must also monitor according to numeric effluent limitations (NELs) and monitor receiving water.

The Storm Water Pollution Prevention Plan (SWPPP), one of the PRDs, must be developed to meet site-specific objectives. These include, but are not limited to, descriptions of the project and site, construction schedule, the efficacy of site-specific Best Management Practices (BMPs), support for selecting BMPs, and Rain Event Action Plans. Dischargers must appoint a Qualified SWPPP Developer (QSD), and a Qualified SWPPP Practitioner (QSP) to oversee implementation of BMPs. Evidence of the training qualification and certification of the QSD and QSP must be included. In addition, SWPPPs must address the objective of developing stabilization BMPs for after project-completion. SWPPPs must be available for inspection at the construction site during working hours while construction is occurring, and be made available upon request by a State or Municipal inspector.