Performance of a Constructed Wetlands in Treating Urban Stormwater Runoff

Abstract

An investigation was conducted on the pollutant removal performance of a constructed wetlands treating stormwater runoff from a residential townhome complex in northern Virginia. Constituent event mean concentrations for 33 runoff events between April 1996 and May 1997 were measured based on flow‐weighted composite samples collected at the facility's inlet and outlet. With the results from a limited number of grab samples representing ungauged overland drainage from an adjacent wooded area, estimated removals were positive for most constituents and typically exceeded those obtained at a nearby companion wetland study site, consistent with expectations based on the relative ratios of wetland area to drainage area at the two sites. Median load removals of all constituents were greater for a subset of 22 storms that had inflow volumes less than the maximum volume of the marsh. Orthophosphate phosphorus and ammonia removals were significantly better during spring of 1996 than spring of 1997. Lysimeter data suggest a possible explanation for this, which is development of anaerobic conditions in the shallow sediments in 1997. Outlet concentrations of oxidized nitrogen were consistently lower in base flow than in storm samples, suggesting that removal of this constituent occurred primarily between, rather than during, storm events.

Variability in adsorptive phosphorus removal by structural stormwater best management practices

“…Traditional urban stormwater management often utilized dry detention ponds and focused on peak flow attenuation while doing little to address nutrient impacts. More recently, wet retention ponds designed with permanent pools have been introduced in an effort to address stormwater quality along with quantity (Carleton et al, 2000;Hogan and Waldbridge, 2007). These stormwater ponds are ubiquitous in the American urban landscape with an estimated 2.6 million such ponds across the contiguous US (Smith et al, 2002).…”

“…Other BMPs have been investigated for urban stormwater treatment, including stormwater wetlands (Carleton et al, 2000;Kadlec and Wallace, 2009) and have performed effectively, but land availability is a common limitation. Traditional designs are often land intensive and not economically feasible in urban areas (Hunt and Wossink, 2003).…”

“…This removal percentage is assumed constant regardless of changes in internal parameters (such as substrate type, redox potential, and pH) or external parameters (such as flow rate and "antecedent dry period") that have been suspected of causing variation (Carleton et al, 2000;Pant et al, 2001;Farahbakhshazad and Morrison, 2003;Naylor et al, 2003;Arias and Brix, 2005;Shilton et al, 2005).…”

Towards a Constructed Wetland/Reservoir- Tank System for Rainwater Harvesting in an Experimental Catchment in Colombia

“…Initially, these systems were designed for flood control: collecting, storing, and treating stormwater; also to minimize the effects on the infrastructure (such as soil impermeabilization and increase of water demand) and the anthropic activity on the quality of water [27]. The application of SUDS is a current topic (except in Africa); around the world there are successful SUDS experiences: USA [28], United Kindom [29], Chile [30], Malaysia [31], Australia [32], China [33], Korea [34], and Greece [35].…”

Performance of a Catch Basin Filter and Leachate from Biocidal Media for Stormwater Treatment

“…Constructed wetlands for the treatment of urban and agricultural stormwater are of recent interest due to their natural tendencies to filter and absorb nutrients and other contaminants from water. One study found decreased contaminant concentrations in the effluent from a constructed wetland, created by the simple installation of an outlet weir to an existing dry detention pond and the growth of natural volunteer wetland species (Carleton et al, 2000).…”