Orange County Branch Newsletter

May 2014

Branch News

State of Environment in Orange County

By: Remi Candaele, P.E.

Have you ever wondered if, from a water quality standpoint, it is truly safe to swim in our local OC waters? Grant Sharp, Environmental Monitoring Manager with OC Watersheds, presented the findings of a newly-released report, entitled “State of the Environment for the Santa Ana Region of Orange County – 2013 Report of Waste Discharge” to a large group of environmental, water quality, and flood control professionals at the Joint OC Branch/EWRI Monthly Meeting. The comprehensive report focuses on priority issues and contaminants impacting surface water quality in Orange County  and aims to address two key questions: “is it safe to swim in our waters?” and “are our aquatic ecosystems healthy?”.

Stormwater runoff from the Orange County municipal separate storm sewer system (MS4) has been regulated by Phase I National Pollutant Discharge Elimination System (NPDES) permits since 1990. In response to these “MS4 Permits”, a cooperative program called the Orange County Stormwater Program (Program) was established by the municipalities and monitoring of the quality of stormwater runoff and the health of receiving waters has been an important measure of its effectiveness. The State of the Environment report is an in-depth analysis of current conditions, utilizing data collected over the last two decades in some cases. Bacteria, nutrients, and toxicity were identified as the pollutants of highest priority. Grant explained that since the early 2000’s, significant progress has been made in addressing bacteria during dry weather, through a combination of efforts, including reducing the number of sanitary sewer overflows and implementing engineered controls of non-stormwater runoff. This has resulted in Orange County Beaches receiving A grades from Heal the Bay more than 90% of the time, well above the State average. The Program is in the process of exploring the use of scientific advances in DNA analysis to assist with source investigations where beach water quality exceeds public health standards for bacteria.

Exceedances of nutrient water quality objectives are still widespread throughout the MS4, yet the efforts to control mass loading of nutrients to Newport Bay have been highly successful. For those who remember, large algae blooms were a common occurrence in Newport Bay in the late 1980’s.  Over the last two decades, the Program has focused on identifying the nutrient dynamics within the Newport Bay watershed to implement specific actions, such as control of dry weather runoff,  to manage shallow groundwater from the Swamp of the Frogs. Since 1995, the level of nutrients within the Bay have significantly been reduced and the density of algae have been cut by a factor of 4.

Grant mentioned that in analyzing toxicity data,  there are no apparent trends that point to metals in urban stormwater runoff as a major source. Recent monitoring efforts indicate that aquatic toxicity is likely driven by pesticide use in the urban environment. Future efforts to control toxicity from pesticides will focus on educating the public about appropriate. Grant invited the audience to read the State of the Environment report and check out up-to-date monitoring data and other information at the OC Watersheds Water Quality Monitoring Portal:

The monthly meeting concluded with an exchange of questions between the group and Mr. Sharp. Grant’s presentation is linked below :

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