Five Years of IGP Non-Industrial Source Demonstrations: Best Practices and Lessons Learned
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According to the Storm Water Multiple Application Reporting and Tracking System (SMARTS), there are approximately 2,800 facilities covered by the California Industrial General Permit (IGP) that have been elevated to Level 1 or Level 2, thus requiring additional control measures or technical demonstrations to comply with the IGP exceedance response action (ERA) process.

Additionally, due to the July 1, 2018 amendment, certain facilities located in Total Maximum Daily Load (TMDL) watersheds have become subject to numeric effluent limitations (NELs) and risk non-compliance and mandatory minimum penalties for NEL exceedances. Many of these facilities have been faced with compliance costs that could impact their ability to continue operating and have been carefully evaluating various compliance alternatives, typically to avoid costly structural treatment. One alternative to structural treatment outlined in IGP Section XII.D is the background demonstration or the non-industrial demonstration (NISD) to demonstrate that numeric action level (NAL) exceedances are solely attributable to background or non-industrial sources. Successful demonstrations not only have the potential to avoid structural treatment, but unless parameters are SIC-code based or RWQCB-required, they also can result in the removal of monitored parameters, thereby potentially removing NEL applicability.

However, successful background demonstrations and NISDs are not always feasible and even if non-industrial sources of a parameter are present, the industrial source contribution can negate the demonstration entirely. To aid facilities in developing and implementing hypothesis-driven NISDs, Geosyntec authored the first statewide NISD manual for atmospheric sources for CASQA's IGP Subcommittee over five years ago. Since then, Geosyntec has implemented this approach and completed multiple successful NISDs at a variety of facilities, including refineries, lumber yards, manufacturing facilities, and gravel mining facilities, to name a few.

This presentation will detail lessons learned and new tools to assist sites with successful NISDs, potentially avoiding unnecessary treatment and TMDL NELs. We will present case studies, including a detailed look at the hypotheses presented, study design, and conclusions drawn. These examples will include a variety of facility types and complexities including accounting for comingling of industrial and non-industrial sources and developing multiple lines of evidence to support NISDs. The case studies will facilitate a discussion of the lessons learned and best practices for future NISDs. We will also outline scenarios to demonstrate how practitioners can evaluate where and when an NISD is appropriate and potentially successful, including a discussion of the importance of accurate pollutant source assessments and understanding the implications of SIC codes.

This presentation will be interactive by inviting audience members to share their experiences. For example, taking a poll on what pollutants are of most concern and which of them they think may have non-industrial sources. Additionally, we'll ask if anyone watching has successfully submitted an NISD and for what pollutants.

This presentation will be relevant to a wide audience as the diverse set of case studies offers lessons learned and best practices covering a variety of pollutants, allow the audience to understand the likelihood of completing a successful NISD for their facility and whether it would actually lessen the compliance/cost burden. This presentation ties directly into the 2021 theme of "recovery and resilience" by outlining a sustainable, comparatively low-cost pathway for industrial dischargers to meet IGP requirements and continue operating their businesses, thus providing local and regional economic benefits, in addition to the water quality benefits associated with permit compliance.

Publication Summary

  • Geosyntec Authors: Maia Colyar, Kaylin Boeckman
  • All Authors: Maia Colyar, Kaylin Boeckman
  • Title: Five Years of IGP Non-Industrial Source Demonstrations: Best Practices and Lessons Learned
  • Event or Publication: CASQA 2021
  • Practice Areas: Water and Natural Resources
  • Citation: Speakers: Maia Colyar, Kaylin Boeckman, Geosyntec Consultants Date/Time: Tuesday, Oct. 26 2:00-2:25 p.m. PST
  • Date: Oct. 26, 2021
  • Location: California
  • Publication Type: Platform Presentation