Choose Your Own Exceedance Response Action Adventure: If at First You Don't Succeed, Try Another BMP
« All Publications

Many stormwater professionals, specifically consultants, can agree that we primarily do what we do for three reasons: (1) to enhance and protect the quality of our waterways, (2) to utilize our critical thinking skills and knowledge of stormwater best management practices (BMPs) to solve complex problems, and (3) because we are genuinely interested in helping our clients achieve their goals with the, oftentimes, limited resources available to them.

This presentation will highlight an Exceedance Response Action (ERA) Level 2 success story where client/consultant communication and collaboration, creative thinking, and a willingness to consider that it may take a combination of BMPs to eliminate a Numeric Action Level (NAL) exceedance were essential in forging a path back to Baseline for a southern California dairy product manufacturer.

As dischargers navigate the world of ERAs, it can be difficult to determine where to start with respect to getting back to Baseline, assuming that is a viable option for the facility. It seems like there are endless possibilities and a multitude of questions are raised; such as, what are the potential sources of the exceedance(s)? how can those sources be eliminated or minimized? and what could addressing the exceedance(s) potentially cost? This case study will explore one approach to answering these questions, and others, for a Level 2 discharger and cover the following main ideas: 1. Critical thinking regarding potential sources; 2. Strategic selection of sampling locations to characterize runoff from suspected source areas; 3. Financial impact analysis/evaluation of alternative courses of action based on an array of potential BMPs; 4. Phased or treatment-train approach to BMP implementation; and 5. Importance of communication, teamwork, and collaboration.

This presentation will be directly applicable to facilities currently in either ERA Level 1 or 2. The presentation will begin by posing the question, "how many of you are dischargers or consult for clients whom have remained in Baseline for all monitored constituents since the effective date of the 2014 IGP?" The expectation is that the number of hands raised will be few to none which will make this presentation applicable to most audience members. The approach is scalable and meant to illustrate that the pathway back to Baseline is not one size fits all and does not always require costly full-capture and treatment. A key takeaway is that it is imperative to evaluate budget constraints and potential alternative BMPs early in the process.

Overall, the implications of this approach are far reaching for other facilities who wish to return to Baseline. This case study showcases an instance where a client who was willing to mix and match BMPs to suit their budget and space limitations was successful at returning to Baseline for a ubiquitous constituent (zinc). Due to strategic BMP selection and placement from a list of many potential alternatives, the site has collected four consecutive QSE samples with zero NAL exceedances for zinc and is expected to return to Baseline for zinc on July 1, 2019.

Publication Summary

  • Geosyntec Authors: Julie Walters
  • All Authors: Julie Walters
  • Title: 2019 CASQA Annual Conference
  • Event or Publication: Event
  • Practice Areas: Urban Stormwater Management Planning and Design
  • Citation: Geosyntec will make substantial technical contributions at the California Stormwater Quality Association (CASQA) Annual Conference at the Monterey Conference Center in Monterey, California on October 7-9, 2019.
  • Date: October 7-9, 2019
  • Location: Monterey, California
  • Publication Type: Platform Presentation