Successful mitigation of stormwater-driven nutrient, fecal bacteria and suspended solids loading in a recreational beach community. (1st March 2021)

• Record Type: Journal Article
• Authors: Grogan, Amy E.; Mallin, Michael A.
• Is Part Of: Journal of environmental management. Volume 281(2021)
• Publication Date: 2021-03-01
• Subjects: Best management practice (BMP) -- Stormwater runoff -- Nutrient loading -- Fecal indicator bacteria (FIB) -- Infiltration; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2020.111853
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Marine and estuarine waterways adjacent to urban areas are often the final recipient of polluted stormwater runoff. Microbial degradation of coastal water quality is a direct threat to human health through fecal contamination of bathing waters and shellfish, as well as distressing local economies through the loss of waterways to commercial (shellfishing) and recreational use. In coastal waters reduction of nitrogen loading is a key strategy for prevention of noxious and toxic algal blooms. Best management practices (BMPs) can be successful tools for mitigating such pollutants in runoff, but BMPs must be tailored to individual situations for maximum effectiveness. This study examines the efficacy of a set of BMPs installed in the coastal resort Town of Wrightsville Beach, North Carolina, USA. The BMPs targeted the highly-impervious (90%+) drainage area of two stormwater outfall pipes emptying into recreationally used Banks Channel. Mitigation measures included replacement of impervious pavement with pervious concrete and construction of an infiltration chamber in the parking lot of a local recreational seaside club. Significant reductions were achieved in total stormwater discharge (62%), as well as loading of the fecal indicator bacteria Enterococcus (76%) and total nitrogen (TN – 87% decrease). Additionally, there were reductions in loading of total phosphorous (TP) and total suspended solids (TSS) to estuarine waters following BMP installment. The set of BMPs applied here have wide management applicability to coastal ecosystems, as well as freshwater riparian areas characterized by sandy, porous soils. Graphical abstract: Image 1 Highlights: A best management practice (BMP) employing pervious surfaces and infiltration effectively reduced stormwater pollution in a beach resort town. The load of total nitrogen (TN) and Enterococcus from stormwater runoff was reduced by 86.9% and 76.3% respectively following BMP installment. Total stormwater discharge was significantly reduced by the BMP, minimizing the impacts of pollutants entering a recreational waterway. The highlighted BMP has wide applications for coastal ecosystems and freshwater riparian areas characterized by sandy porous soils.