Jason D Wright

Field Evaluation of Storm-Water Control Measures for Highway Runoff Treatment

The thousands of kilometers of highways in North Carolina have the potential to generate large amounts of storm-water runoff. Thus, investigation of storm-water control measures (SCMs) for these somewhat unique linear catchments, where space is limited for SCM implementation, was needed. This study examined the quantity and quality of highway runoff at four sites over a 48-km stretch of Interstate 40 in the coastal plain of North Carolina. The highway had a 4-cm overlay of permeable asphalt, known as permeable friction course (PFC), which influenced the export of sediment-bound pollutants and produced median effluent concentrations of total suspended solids (TSS) of 8  mg/L , 8  mg/L , 9  mg/L , and 17  mg/L at the four sites, well below concentrations observed from standard asphalt highway runoff. Two vegetative filter strips (VFSs), two traditional dry swales, and two wetland swales were also tested for pollutant removal efficacy at the four highway research sites. The filter strips generally produced h...

Field Evaluation of Indicator Bacteria Removal by Stormwater BMPs in North Carolina

In the United States Environmental Protection Agencys National Water Quality Inventory in 2000, 13% of the river and stream miles that were surveyed were impaired by pathogen indicator bacteria (USEPA 2002). Stormwater runoff is a transport mechanism for indicator bacteria to receiving waters, resulting in an increased risk to public health through consumption of contaminated shellfish or ingestion by swimmers. Urban stormwater is commonly treated by stormwater Best Management Practices (BMPs), each of which provides some combination of natural treatment mechanisms and fosters certain environmental conditions. Although BMPs have been studied in detail for many pollutants, little peer-reviewed literature is available which documents their ability to remove or inactivate indicator bacteria. The North Carolina State University Department of Biological and Agricultural Engineering evaluated 10 stormwater BMPs in Charlotte and Wilmington, NC, to evaluate their efficiency with respect to indicator bacteria removal. The study practices included two bioretention cells, four stormwater wetlands, two wet ponds, and two dry detention areas. Data collected from these studies indicates that positive removal of indicator bacteria is possible in many types of BMPs; however, removal can be highly variable from practice to practice. Further, stormwater BMPs may foster environments where indicator bacteria can persist, becoming sources of indicator bacteria. Finally, even if positive reductions in indicator bacteria are noted, research indicates that achieving effluent concentrations of indicator bacteria consistent with USEPA standards may be difficult with many types of BMPs.

Demonstration and Monitoring of Rainwater Harvesting Technology in North Carolina

Water conservation has grown in importance across North Carolina, as much of the state has recently suffered moderate to severe drought conditions. In addition to meeting water conservation needs, rainwater harvesting systems (cisterns) have an important application in low impact development (LID) as innovative stormwater management practices. A total of four cisterns were installed in each of the main physiographic regions of North Carolina: Craven County (coastal plain), Cumberland County (sandhills), Guilford County (piedmont), and Watauga County (mountain). These systems demonstrate above ground and in-ground applications. Uses for the captured stormwater include irrigating landscapes and gardens, washing vehicles, an additive for brine applied to icy streets and flushing kennels at an animal shelter. Each site is being monitored for water quantity and usage, and one system is monitored for water quality. Results will help establish the water quantity and quality benefits of rainwater harvesting systems and will influence design recommendations to be incorporated in the State of North Carolina’s new Stormwater BMP Design Manual.

Implementation of Low Impact Development Retrofits in a Low Income Neighborhood in Wilmington, NC

Burnt Mill Creek, located within downtown Wilmington, NC, is on the EPAâ€TMs 303(d) list for impairment due in large part to urban stormwater runoff. The urban nature of the watershed presents challenges for restoration because of the varying land uses including single and multifamily residential areas, recreational parks, and commercial and industrial areas. Watershed Education for Communities and Local Officials (WECO) of NC State University (NCSU) coordinated a partnership, with NCSU Dept. of Biological and Agricultural Engineering (BAE), as well as several other key state and local organizations and citizens groups, to obtain an EPA 319 grant that addresses stormwater management in the watershed. Collaboration with community leaders has led to several retrofit opportunities and successful partnerships. Often in large scale watershed retrofit projects, education and retrofit opportunities in low income areas are overlooked. This paper focuses specifically on the partnership with one citizens group, the Bottom Neighborhood Empowerment Association (BNEA). The bottom area, called the bottom because it is one of the lowest points in the watershed, is a dense urban neighborhood where many residents have incomes lower than the median income of Wilmington and New Hanover County (Wilmington median income is

Restoration of a prior converted farm in Eastern NC with multiple target wetland communities

42,000, New Hanover County

An Evaluation of Pathogen Removal in Stormwater Best Management Practices in Charlotte and Wilmington, North Carolina

41,000; areas in BMC between

Innovative Stormwater Retrofits For Barrier Island Applications: Septic Tank Conversion In Holden Beach, NC

22,000 and

Implementing Stormwater Best Management Practice Retrofits in Wilmington, NC

34,000 depending on census tract) (NC Census, 2000). BNEA is a group of citizens living in the bottom area who are working to improve the quality of life in their neighborhood. Cooperation with BNEA has led to several educational and LID retrofit opportunities including three educational workshops held in the community, installation of ten rain gardens in community areas and private residences, and distribution of twenty-four 65 gallon rain barrels. A survey developed and distributed by an NCSU graduate student showed that each resident who responded found some stormwater educational benefit to participating in the workshops and the retrofit efforts.

Field Evaluation of Bioretention Indicator Bacteria Sequestration in Wilmington, North Carolina

EXTENDED ABSTRACT. The goal of wetland restoration/creation projects is to successfully construct a system that exhibits the same structure and beneficial functions as a targeted wetland community in the most efficient manner possible. In an effort to advance the understanding of design and construction techniques used in restoration in eastern NC (USA), faculty from North Carolina State University, teamed with the North Carolina Coastal Federation and the NC Ecosystem Enhancement Program, provided restoration designs and construction oversight for a portion of North River Farms. Located in Carteret County, NC this 2300-ha prior-converted farm had an extensive agricultural drainage network that flowed into sensitive estuarine areas that have traditionally been used for shellfish harvesting. As of January 2008, 122 ha of non-riparian hardwood wetland, 9 ha of riparian freshwater wetlands, and 14 ha of tidal marsh have been constructed at this farm. The riparian freshwater wetlands and tidal marsh are supported by over 2600 m of freshwater stream and tidal creeks constructed to flow through the site.

Rainwater Harvesting Experiences in the Humid Southeast USA

Pathogens are a target pollutant in many parts of North Carolina, particularly in areas that drain to shellfish waters. Standards have been established for pathogen indicators in fresh water (200 cfu/ 100 ml for fecal coliform, 126 col/100 ml for E. coli, and 33 cfu/100 ml for enterrococcus) and marine waters (35 cfu/100 ml for enterrococcus) being used as full body recreational areas in an attempt to reduce public health risks. Runoff samples collected from urbanized watersheds often are high in pathogenic indicator bacteria, leading to the need for treatment (Bright, 2007; MOAWMS, 2003; Schoonover and Lockacy, 2006). However, there is little peer reviewed literature regarding stormwater Best Management Practice (BMP) treatment of pathogens. The NCSU Biological and Agricultural Engineering Department monitored 14 stormwater BMPs, 9 in Charlotte, NC, and 5 in Wilmington, NC, to evaluate their efficiency with respect to indicator bacteria removal. The study locations included 2 bioretention areas, 4 stormwater wetlands, 3 wet ponds, 2 dry detention, and 3 proprietary BMPs.