Source Molecular Joins Swimmable California Webinar Series

Source Molecular Corporation’s Dr. Yiping Cao recently talked about quantitative microbial risk assessment (QMRA) eligibility in the Swimmable California Webinar Series hosted by the California Water Quality Monitoring Collaboration Network.

The Collaboration Network is a statewide forum where monitoring community members share ideas, successes and common concerns. It was launched by the California Water Quality Monitoring Council in partnership with the State Water Resources Control Board and the U.S. Environmental Protection Agency.

Dr. Cao, Source Molecular’s Vice-President of Technology, gave a highly informative 30-minute presentation entitled, “QMRA Eligibility: Molecular Source Tracking and Disease Detection”, on March 21, 2018.

“The concept of using QMRA to establish site-specific alternative criteria is to provide equivalent public health protection,” Dr. Cao said. She noted that in 2012, there was a shift in regulatory focus of recreational water quality from fixed numeric standards to a risk-based framework, putting more focus on public health risk.

“If the FIB (fecal indicator bacteria) sources in your site are mostly non-human or non-fecal, the EPA allows establishment of site-specific criteria based on QMRA. But the question is how do you demonstrate that the sources in your site are predominantly non-human? How do you prove that the human fecal contribution at your site is minimal in a scientifically sound and statistically defensible manner?”

Swimmable California Webinar

Based on her extensive research experience and collaborations with other scientists, Dr. Cao shared the scientific thought process on how to address the QMRA eligibility question and provided recommendations on how to demonstrate that human fecal contribution at a site is minimal. She suggested that stakeholders take the initiative to obtain the best study design and data to enable regulator decision making.

Dr. Cao also recommended using the HF183 marker because this is the most tested and best marker for human fecal contamination. She also recommended the use of digital PCR (polymerase chain reaction) over quantitative PCR (qPCR) because it is far more superior technology. Source Molecular offers the HF183 marker on both dPCR and qPCR platforms.

Before joining Source Molecular, Dr. Cao worked at the Southern California Coastal Water Research Project (SCCWRP). She is a leading expert on applying molecular technology and statistical modeling for water quality improvement.

The webinar series focus on elements that support California’s water monitoring and management programs. Webinar topics and schedule are available at the My Water Quality website. Source Molecular had joined this webinar series in the past, with CEO Mauricio Larenas discussing various MST developments including Digital PCR. Watch Mr. Larenas’ 2015 MST presentation here.

Visit Source Molecular’s website,, for more information about its genetic testing services and how it can support various water quality monitoring efforts. Scheduling appointments is also available, just select the most convenient time.