Human Fecal Score(TM) Featured in Stormwater Magazine

An article contributed by Source Molecular Corporation about a mathematically defined standardized approach to estimate the extent of human fecal pollution at a site was published in the August edition of the Storm Water Solutions (SWS) magazine.

Source Molecular’s global head of business development, Daron Stein, authored the article for publication in the SWS magazine to reach a wider audience for the Human Fecal Score (HFS). The HFS is particularly valuable to stormwater managers who will benefit from the easy comparison of sites, allowing them to prioritize site remediation.

Source Molecular’s Vice President of Technology, Dr. Yiping Cao, was involved in the development of the HFS algorithm along with a team of researchers from the U.S. EPA, Stanford University and Southern California Coastal Water Research Project Authority. The researchers were able to produce an estimate of the level of fecal contamination at a given site based on the average concentration of human fecal-associated marker called HF183 in water samples collected over a defined period of time. If the score of a site is higher than others, it means it is more polluted.

The HFS came about because researchers discovered some subjectivity issues when it comes to MST data interpretation. Because of inconsistencies in experts’ Best Professional Judgment (BPJ), researchers saw the need for a more objective approach in interpreting MST data.

What makes the HFS different from BPJ is that it uses all site data, regardless if it is non-detect (ND), did not quantify (DNQ) or quantifiable data. Researchers believe this gives a more accurate picture of the site condition and eliminates the bias introduced by ignoring ND, DNQ or arbitrary data substitution.

For more information about the HFS and its applications to water quality management, contact Daron Stein at or 786.404.1675. Source Molecular is the nation’s leader in the field of microbial source tracking.