Quantification of the contribution of wastewater effluent to coastal ocean acidification

Lead Pi: Scott Doney · 02/2016 - 08/2018

Project Personnel: Geoffrey Cowles, James Churchill, Jennie Rheuban

Project number: 2016-R/RC-143
Strategic Focus Area: Healthy Coastal Ecosystems

This project seeks to understand the effect of effluent from wastewater treatment plants, specifically those in Fairhaven, New Bedford, and Wareham, on the acidification of coastal waters in Buzzards Bay. Mathematical modeling of the effluent plumes using tracers will be combined with field sampling of carbonate chemistry and nutrients in the plumes — namely, dissolved inorganic carbon and total alkalinity using titration methods; pH using spectrophotometric methods; nutrients including NO3-+NO2-, NH4+, PO4-3, SiO4-, TN, PON, and POC; and organic matter enrichment of sediments. Modeling efforts will use and refine the Southeastern Massachusetts hydrodynamic model (SEMASS-FVCOM). Coastal acidification destroys economically important habitats that support aquaculture and commercial fisheries, and little is known about the contribution of outflow from townsí wastewater treatment plants. If this study shows that wastewater treatment plants are strong point sources of dissolved inorganic carbon, FVCOMís high-resolution hydrodynamic/plume tracking model can help design mitigation strategies such as sewer expansions, changes to levels of wastewater treatment, and re-siting of effluent outfall pipes