Current mercury characterization efforts require weeks of lead time for laboratory analysis, developing Real Time predictive modeling provides instantaneous approximations of mercury concentrations. Having real time approximations of trace level mercury levels provides many projects the ability to adapt and change so as to reduce mercury transport as a result of their project. The Sierra Fund has developed a framework for high frequency data collection that when coupled with site-specific sampling can be used to build site-specific model for mercury concentrations.
“Real-Time Monitoring provides project managers the information they need to reduce the impact that maintenance, restoration or remediation activities in and around mercury impaired water bodies may create. Mercury contamination can be mobilized while restoring habitat and when maintaining facilities in mercury-contaminated water bodies.”
Using Real-Time Monitoring as a predictive approach to mercury monitoring is an advancement to current mercury sampling protocols and procedures where samples are required to be immediately stored on ice, shipped overnight, and sent to a laboratory that is certified to carry out EPA Methods 1630 and 1631 for mercury analysis. Developing mercury predictive models allow for real-time decisions to be made about operations and help to eliminate the risk of downstream propagation of mercury-contaminated sediments. This project provides a framework for regional real-time mercury monitoring in the hydraulic mining-impacted region of the northern Sierra Nevada.
The Sierra Fund constructed two continuous real-time data collection platforms (DCP’s) and implemented a paired sampling effort for filtered (f-THg) and particulate (p-THg) mercury at the upstream and downstream ends of a sediment and mercury abatement effort at Combie Reservoir. Real-time continuous monitoring stations were outfitted with the ability to collect high frequency data such as turbidity, total suspended solids (TSS), total dissolved solids (TDS), and fluorescent dissolved organic matter (fDOM). An ANOVA multiple regression analysis for the creation of a predictive proxy for filtered and particulate mercury concentrations were developed using lab results for total and filtered mercury and the data collected from the DCP’s. The mercury predictive model was applied to the DCP output and relayed to project engineers and managers for real time adaptive management capabilities.
Having the ability to calculate statistically significant p-THg and f-THg concentrations instantaneously is revolutionary in the realm of trace metal sampling. For mercury impacted water bodies within the Sierra Nevada, this framework of data collection and predictive qualities will facilitate the efforts to address legacy Hg-contamination.
Implementation of Real-Time Monitoring and site-specific mercury predictive models similar to what was done for the Combie Reservoir Sediment and Mercury Removal Project will aid in the development of future sediment removal projects at similarly mercury impacted reservoirs in the state.