Source Molecular Corporation’s Yiping Cao emphasized the importance of identifying fecal bacteria sources at a seminar in the University of California, Irvine, in December 2017. She discussed a study that identified sources of fecal contamination and a study to evaluate biofilter effectiveness in removing microbial pollution.
The Department of Civil and Environmental Engineering in the Henry Samueli School at UCI hosted the seminar series. Dr. Cao’s presentation was entitled “The Engineering Story of Beach Water Quality”. Before becoming Source Molecular’s Vice-President of Technology, Dr. Cao was a senior microbiologist with the Southern California Coastal Water Research Project (SCCWRP).
Fecal contamination of water sources is creating a huge problem around the world, resulting in beach closures and cascading negative effects on businesses and communities. In the U.S., microbial water quality is a big issue with “pathogen” ranking number one in the list of pollutants. But Dr. Cao clarified that this “pathogen” listing is actually fecal indicator bacteria (FIB) listing, which are not the same thing.
“Direct measurements of pathogens is difficult because their diversity is high and concentrations are usually low,” Dr. Cao said. On the other hand, FIB are abundant in fecal material and easier to measure than pathogens.
Bacteria Sources and Water Quality Monitoring
Dr. Cao said the current system for monitoring is flawed because it automatically associates FIB with disease. “There is a disconnect between what is monitored or regulated, and what we are concerned with.” FIB themselves are generally not pathogens.
Furthermore, Dr. Cao noted that FIB does not distinguish between sources and thus it hinders source abatement. “Source identification must precede mitigation,” Dr. Cao stressed. She explains that not all sources present the same level of human health risk. Human fecal waste presents a greater public health risk than animal fecal waste.
Microbial source tracking is one of the methods used to identify bacteria sources. There are special microbes that are only associated with a given source. Thus, these MST genetic markers can be used to identify sources of contamination.
Dr. Cao also discussed Low Impact Development (LID), used increasingly to manage stormwater. Biofilters are a popular choice for LID best management practices. However, current evaluation of biofilter effectiveness in removal microbial pollutants are limited and focuses on FIB only. Dr. Cao is leading a study using field scale biofilters to evaluate removal efficiency of FIB, MST marker and pathogens, in collaboration with Orange County Public Works and University of California researchers.
Learn more about identifying bacteria sources and how it can help your watershed by selecting your most convenient time for an appointment with us. Source Molecular works with water managers and assists them in improving water quality.