Fluorometry as a bacterial source tracking tool in coastal watersheds, Trinidad, CA
This article is part of a larger document. View the larger document here.Abstract
Bacterial counts have long been used as indicators of water pollution that may affect public health. By themselves, bacteria are indicators only and can not be used to identify the source of the pollutant for remediation efforts. Methods of microbial source tracking are generally time consuming, labor intensive and expensive. As an alternative, a fluorometer can be used to measure fluorescence in natural creeks as an indicator of concentrations of optical brighteners found in laundry detergent. In this way, fluorescence can be used as a tool for identifying failing or malfunctioning onsite wastewater treatment systems. Fluorometry was used in watersheds draining into northern California’s Trinidad Bay in Humboldt County, in conjunction with bacterial sampling and measurement of rainfall and turbidity for correlation and comparison. Results showed that optical brighteners, when coupled with rainfall and turbidity data, can accurately predict whether bacterial standards will be exceeded within individual watersheds. Fluorescence of optical brighteners was also shown to be a useful tool for discerning the most impacted watersheds and tributaries for more detailed investigation of individual bacterial pollution sources.