First Flush: Water Quality Data Collected by Citizen Scientists at Storm Drain Outfalls 2000 - 2014
First Flush is a citizen monitoring program initiated by the Monterey Bay National Marine Sanctuary (MBNMS) in 2000 to monitor pollutants (copper, zinc, lead, nitrate-N, orthophosphate-P, urea, E.coli, enterococcus, total suspended solids, MBAS, fluoride, and ammonia) in storm water entering MBNMS from storm drain outfalls prior to and during the first major rainstorm. When the Monterey Regional Storm Water Management Program (MRSWMP) was adopted by Monterey Peninsula cities in 2006 to reduce storm water pollution, First Flush protocols were also adopted by this regional storm water program. Over the combined period of both programs from 2000 to 2014, trained citizen science volunteers under the guidance of MBNMS have donated more than 3,000 hours collecting water samples and taking field measurements of urban runoff. By following specific protocols for training, team formation, sample handling and other quality assurance guidelines, samples and field measures collected by citizen scientists is valid for investigating long term changes in pollutant concentration and load. In addition, there is added benefit of informing and educating volunteers about storm water quality and how their local municipalities are tackling this complex issue.
Assessing Changes Due to Best Management Practices:
A statistical comparison between First Flush (2000-2006) and MRSWMP monitoring (2007-2014) results was used to ascertain whether Best Management Practices instigated by Monterey Peninsula cities through storm water management plans have led to statistically discernable differences in pollutant concentrations.
Trends at Outfalls:
A trend analysis for each pollutant at each outfall was performed to determine whether concentrations have increased or decreased over the monitoring period of the combined First Flush and MRSWMP programs.
Outfall Concentrations Over Time Compared with Top 85th Percentile Concentrations:
Combined First Flush and MRSWMP data was analyzed to determine the top 85th percentile representing the highest concentrations for pollutants of concern (copper, zinc, lead, nitrate-N, orthophosphate-P, urea, E.coli, enterococcus, total suspended solids, MBAS, fluoride, and ammonia) from the collective data of all sites and used to identify which outfalls exceeded this threshold. Plots of outfall site concentration show the entire time range compared with the 85th percentile and provide a visual means to assess each site individually and comparatively with other sites.
Instantaneous Pollutant Load Showing Monterey Peninsula Cities Outfalls Side by Side:
Pollutant load differences between outfalls within each City, displayed by barcharts, show annual wet and dry instantaneous load for each pollutant. These load barcharts are helpful in making a relative determination of which outfalls in each city contribute the highest level pollution entering the MBNMS. This information can then be used for problem solving and targeted BMP development for specific pollutants and locations.
Take Away Tools for the Audience:
• What statistical tests can help discern trends in small data sets and why more data is needed to avoid missing trends due to statistical limitations.
• How to compare pre and post BMP data to determine if a change occurred.
• How a citizen monitoring effort can be successful in collecting reliable data.
• How to display data to more easily see differences and to make comparisons between sites.
• Stories about citizen monitoring, what can happen and how to minimize mistakes.
• Questions will be asked of the audience regarding visual data displays and discussion of how well these represent information that can be interpreted and used to ascertain where change is needed or whether change has happened. Prizes will be given!