The Presence of Denitrifiers In Bacterial Communities of Urban Stormwater Best Management Practices (BMPs)

Natalie C Hall,R Christian Jones,Dianna Hogan,Patrick M Gillevet,Masoumeh Sikaroodi

doi:10.1007/s00267-021-01529-z

Natalie C Hall, R Christian Jones + Show 3 more

Open Access

https://doi.org/10.1007/s00267-021-01529-z

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Abstract

Stormwater best management practices (BMPs) are engineered structures that attempt to mitigate the impacts of stormwater, which can include nitrogen inputs from the surrounding drainage area. The goal of this study was to assess bacterial community composition in different types of stormwater BMP soils to establish whether a particular BMP type harbors more denitrification potential. Soil sampling took place over the summer of 2015 following precipitation events. Soils were sampled from four bioretention facilities, four dry ponds, four surface sand filters, and one dry swale. 16S rRNA gene analysis of extracted DNA and RNA amplicons indicated high bacterial diversity in the soils of all BMP types sampled. An abundance of denitrifiers was also indicated in the extracted DNA using presence/absence of nirS, nirK, and nosZ denitrification genes. BMP soil bacterial communities were impacted by the surrounding soil physiochemistry. Based on the identification of a metabolically-active community of denitrifiers, this study has indicated that denitrification could potentially occur under appropriate conditions in all types of BMP sampled, including surface sand filters that are often viewed as providing low potential for denitrification. The carbon content of incoming stormwater could be providing bacterial communities with denitrification conditions. The findings of this study are especially relevant for land managers in watersheds with legacy nitrogen from former agricultural land use.

Highlights

IntroductionStormwater runoff transports sediments and other pollutants such as nutrients into receiving water bodies, which can cause a host of problems for urban streams including a decrease in dissolved oxygen (O2) levels and eutrophication (Vitousek et al 1997; Howarth et al 2002; Rabalais 2002; Wolfe and Patz 2002; Walsh et al 2005)
Urbanization is associated with an increase in impervious cover as land use changes from forest, agriculture, and other forms of more highly vegetated land to residential and1 U.S Geological Survey, Florence Bascom Geoscience Center, Reston, VA, USASoutheast Region, Reston, VA, USA 5 Department of Environmental Science and Policy, George MasonUniversity, Fairfax, VA, USA 6 Potomac Environmental Research and Education Center (PEREC), George Mason University, Woodbridge, VA, USA commercial development
There was clustering by best management practices (BMPs) type in the DNA-derived dataset, with some overlap between bioretention facilities (BFs) and dry ponds (DPs), indicating similar bacterial communities by BMP type

Summary

Introduction

Stormwater runoff transports sediments and other pollutants such as nutrients into receiving water bodies, which can cause a host of problems for urban streams including a decrease in dissolved oxygen (O2) levels and eutrophication (Vitousek et al 1997; Howarth et al 2002; Rabalais 2002; Wolfe and Patz 2002; Walsh et al 2005). These conditions have collectively been termed “the urban stream syndrome” (Walsh et al 2005). Low impact development or green infrastructure design uses BMPs to mitigate the effects of impervious surface cover with the use of stormwater infrastructure in a way that

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