Microbial Source Identification Study for Buccaneer Beach and Loma Alta Creek

Date / Time:
Tuesday, Oct 16 2:45pm to 3:15pm
Raincross B & E (Upper Level)
Track / Session:
Total Maximum Daily Loads Track / Bacterial TMDLs

Microbial Source Identification Study for Buccaneer Beach and Loma Alta Creek
Justin Gamble, City of Oceanside
Alexander Schriewer, PhD, Weston Solutions

The Loma Alta Slough (Slough) is a three-acre coastal estuarine wetland located at the terminus of Loma Alta Creek at Buccaneer Beach in the City of Oceanside. Loma Alta Slough and Buccaneer Beach are both listed on the State of California Section (§) 303(d) impaired waters list due to elevated levels of fecal indicator bacteria (FIB). Prior monitoring data from the City of Oceanside show that the dynamic sand berm at the mouth of Loma Alta Slough is a major factor affecting the transport of FIB from the watershed to the beach, which, depending on the sources of FIB, may present a public health risk for waterborne illnesses. The purpose of the data collected via the Microbial Source Identification Study for Buccaneer Beach and Loma Alta Creek was to implement an effectiveness assessment study to inform the City of how well their existing best management practices are already working, as well as to identify additional mitigation measures to reduce bacteria levels at Buccaneer Beach by determining the likely sources of fecal contamination.

The study was funded by the State Water Resources Control Board through a Clean Beach Initiative (CBI) grant and followed a tiered approach described in the California Microbial Source Identification Manual. The project included several phases including a watershed characterization and historic data review, sampling design, laboratory validation trial, monitoring, data analysis and final recommendations. Each phase was reviewed and confirmed by a technical advisory committee.

This presentation will provide the results of over 200 analyzed samples, the conclusions and recommendations based on these results, as well as a discussion of current BMPs and possible follow up activities and actions. Attendees will be provided with an example of a successful source identification study and its applicability as a tool for watershed managers. The Loma Alta watershed represents a great model for larger watersheds due to its compact size with regards to the design and implementation of microbial source tracking studies for TMDL compliance. The audience will be engaged through interactive questions and answers to ensure that the delivery of the presentation is useful to those in attendance.

Primary Speaker:
Alexander Schriewer, Weston Solutions, Inc.
Dr. Schriewer is an Environmental Scientist with over 15 years professional experience in the assessment of environmental pollution. His expertise includes the gene-specific detection of a range of bio-targets, particularly pathogens and source identification markers. He has lead studies in support of several bacteria TMDLs in California as well as health impact studies in developing countries. He joined WESTON in 2015 and supports the company as Technical Director and Director of Weston’s Molecular Laboratory. He holds a Master in Inorganic Chemistry (2003) and a Ph.D. in Chemistry and Urban Water Management from the Technical University of Munich (2007).
Supporting Speaker 1:
Justin Gamble, City of Oceanside