title: Citizen science-based water quality monitoring: Constructing a large database to characterize the impacts of combined sewer overflow in New York City.
abstract: To protect recreational water users from waterborne pathogen exposure, it is crucial that waterways are monitored for the presence of harmful bacteria. In NYC, a citizen science campaign is monitoring waterways impacted by inputs of storm water and untreated sewage during periods of rainfall. However, the spatial and temporal scales over which the monitoring program can sample are constrained by cost and time, thus hindering the construction of databases that benefit both scientists and citizens. In this study, we first illustrate the scientific value of a citizen scientist monitoring campaign by using the data collected through the campaign to characterize the seasonal variability of sampled bacterial concentration as well as its response to antecedent rainfall. Second, we examine the efficacy of the HyServe Compact Dry ETC method, a lower cost and time-efficient alternative to the EPA-approved IDEXX Enterolert method for fecal indicator monitoring, through a paired sample comparison of IDEXX and HyServe (total of 424 paired samples). The HyServe and IDEXX methods return the same result for over 80% of the samples with regard to whether a water sample is above or below the EPA's recreational water quality criteria for a single sample of 110 enterococci per 100mL. The HyServe method classified as unsafe 90% of the 119 water samples that were classified as having unsafe enterococci concentrations by the more established IDEXX method. This study seeks to encourage other scientists to engage with citizen scientist communities and to also pursue the development of cost- and time-efficient methodologies to sample environmental variables that are not easily collected or analyzed in an automated manner.
authors.affiliation: Department of Earth and Environmental Engineering, Columbia University, 918 S.W. Mudd, Mail Code: 4711, New York, NY, USA. Electronic address: djf2137@columbia.edu.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farnham
authors.affiliation: Department of Geochemistry, Lamont Doherty Earth Observatory, 61 Route 9W, - PO Box 1000, Palisades, NY, USA. Electronic address: rgibson@ldeo.columbia.edu.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Gibson
authors.affiliation: Department of Geochemistry, Lamont Doherty Earth Observatory, 61 Route 9W, - PO Box 1000, Palisades, NY, USA. Electronic address: dhsueh@ldeo.columbia.edu.
authors.forename: Diana Y
authors.initials: DY
authors.lastname: Hsueh
authors.affiliation: Department of Geochemistry, Lamont Doherty Earth Observatory, 61 Route 9W, - PO Box 1000, Palisades, NY, USA. Electronic address: mcgillis@ldeo.columbia.edu.
authors.forename: Wade R
authors.initials: WR
authors.lastname: McGillis
authors.affiliation: Department of Civil Engineering and Engineering Mechanics, Columbia University, 610 S.W. Mudd, Mail Code: 4709, New York, NY, USA. Electronic address: pjc2104@columbia.edu.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Culligan
authors.affiliation: The River Project, Pier 40 at West St. & Houston St, 2nd Floor, New York, NY. USA. Electronic address: nina@riverprojectnyc.org.
authors.forename: Nina
authors.initials: N
authors.lastname: Zain
authors.affiliation: Steering Committee, New York City Water Trail Association and Coordinator, Citizens Water Quality Testing Program, USA. Electronic address: avironvoile@gmail.com.
authors.forename: Rob
authors.initials: R
authors.lastname: Buchanan
keywords: CSO; Citizen science; Fecal indicator bacteria; HyServe Compact Dry ETC; IDEXX Enterolert; Water quality