William Showers

Project Summary: Effective riparian vegetative buffers and wetlands are carbon sinks, minimize nutrient input, soil erosion and related runoff into adjacent surface waters. They are an essential component of livestock environmental resource management and mitigate the movement of nitrogenous and fecal waste from livestock operations and manure management fields into waterways. Watersheds in the coastal plain of North Carolina include a mixture of homes, businesses, livestock operations and other forms of agriculture. Each is a potential source of nutrient and fecal waste in surface waters. Watershed contamination with nutrients or fecal waste are traditionally considered to be non-point sources of contamination. However, all fecal waste has a vertebrate animal origin, and the species of origin varies with adjacent land-use practices. All vertebrates release cells from their gastrointestinal tract in their feces. These cells contain mitochondrial DNA (mtDNA), a routine aspect of forensic investigation that can be applied to identify the animal hosts associated with fecal waste. An mtDNA-based assay we have developed can now specifically attribute the source of fecal waste to humans, livestock (cattle, pigs, poultry, goats), companion animals (dog, cat) and wildlife (white-tailed deer and Canada goose). We propose a comprehensive cross-sectional study to identify locations contaminated by nitrate and fecal waste in mixed use livestock intensive areas of the lower Neuse and Cape Fear watersheds. The study will be conducted with the aim of identifying the presence of fecal contamination and attributing the source of fecal contamination to their species of origin. Water grab samples will be screened for Enterococcus spp. as an indicator of fecal contamination. Samples from positive locations will then be tested for vertebrate mtDNA to attribute the contamination to specific species. Additional sampling at positive sites will assess fecal waste input during storm events. Riparian areas adjacent to waterways testing positive will be visualized using satellite imagery to identify proximity to potential sources of contamination with the identified species. Samples will be assessed for the potential correlation of fecal sources with ammonium, nitrate, chloride, silicate, phosphate, dissolved organic nitrogen and dissolved organic nitrogen. We will conduct community design charettes with cooperating town environmental management personnel and residents, in cooperation with local extension agents and resource managers to identify opportunities for riparian vegetative buffer or wetlands enhancement. Specific objectives include: 1) Identifying locations in agricultural livestock intensive areas where water quality is being degraded by nitrogenous and fecal waste; 2) Identifying riparian locations that will benefit from buffer or wetlands development or refinement; and 3) Working with community stakeholders to develop a plan for buffer and wetland development or refinement. The studies reflect the ecosystem health-oriented objectives of the Environmental Enhancement Grant (EEG) program by facilitating efforts to identify locations that would benefit from either the introduction of vegetative buffers or wetlands or the potential refinement or restoration of existing buffers or wetlands.

Livestock operations generate fecal waste and manure management is an essential aspect of livestock production. Local and state regulations mandate permitting, training, design specifications, and stream vegetation buffers between livestock operations and surface waters. The scale of pork production has increased to meet consumer demand and as production facilities have grown, communities have heightened their concern about the environmental impact of pork operations. Pork producers have worked effectively to reduce their overall water usage, land use, and the carbon footprint of farming operations (National Pork Board, 2018, Thoma et al. 2011). Responsible environmental farm management has become a business necessity for pork producers in the US and producers have affirmed their obligation to manage pork production operations in a manner that protects natural ecosystems and public health. Watersheds, however, generally support multiple types of livestock operations and human dwellings. Each livestock enterprise and residential community is a potential source of fecal waste in surface waters. Fecal waste in surface waters is generally referred to as non-point source contamination. In reality, all fecal waste has a vertebrate animal origin and the species of origin varies with adjacent land-use practices. Monitoring programs established to protect public health have traditionally relied on the culture or detection of fecal coliforms, total coliforms or Enterococcus bacteria in water samples as indicators of fecal contamination in surface waters. These enteric organisms are non-specific indicators of the presence of fecal waste but do not attribute contamination to specific animal hosts. The detection of host-specific enteric organisms, such as Bacteroidales spp. and genetic assays focused on detecting these microbial species have been developed as alternatives to non-host specific indicator organism detection methods (Harwood et al. 2009). All vertebrates release cells from their gastrointestinal tract in their feces. These cells contain mitochondrial DNA (mtDNA), a routine aspect of forensic investigation that can be applied to identify the animal hosts associated with fecal waste (Caldwell et al. 2007). The detection of mtDNA is highly host specific. If mtDNA is detected in a water sample, the vertebrate animal associated with that mtDNA can be determined. Initial studies, however, lacked sensitivity (Caldwell et al. 2009). When we initially developed and tested these assays, at times, fecal waste was present in a stream but not detected. In studies supported by the National Pork Board, we refined these initial mtDNA assays by adapting the use of new Droplet digital PCR technology (BioRad Inc., California, USA), which markedly enhanced the sensitivity of the assay for identifying the presence of host mtDNA in surface waters. New primers and probes were designed, and the assay proved both sensitive and specific. Our studies confirmed the presence of fecal contamination in Stockinghead Creek in Duplin County, NC and documented that the fecal contamination in the creek originates from at least four species, cattle, humans, poultry and swine. This proposal focuses on addressing concerns about the origin of fecal waste in surface waters in other North Carolina livestock intensive watersheds. Specific objectives include: 1) Attributing the source of fecal contamination in NC surface waters in Duplin and Sampson County, NC watersheds ; and 2) Responding to concerns about fecal contamination.

The nitrogen in North Carolina waterways comes from a number of urban, agricultural and rural sources. Nitrogen is applied as a fertilizer to agricultural fields, golf courses and residential lawns. Nitrogen is also a product of the decomposition of waste. Waste is produced by municipal sewage treatment plants, rural septic systems, and in the manure of livestock and poultry. Waste application fields transport nitrate to groundwater and it then enters the rivers as non-point sources. Yet while the non-point sources of nitrogen are known, the pathways that nitrogen takes as it enters North Carolina Rivers, and the amount of nitrogen from each source is not well known. This past year the RiverNet Program has measured nitrate fluxes in the Neuse River Basin during a normal flow year. In addition RiverNet maped non-point nutrient inputs into Neuse Basin watersheds with a new ISUS in situ UV nitrate sensor. Results from this past year indicate that groundwater nitrate enters the river from waste application fields along the northern edge of the plant. This flux is important and adds an additional 50% of the flux of nitrate discharged from the plant from effluent. After three years worth of data long term nitrogen flux trends can be determined. The absolute fluxes are controlled by discharge variations. When the nitrate fluxes are normalized for discharge variations, flux in the lower basin has decreased by about 20% since 2001. However, 5 to 7 years of monitoring data is required to make sure that this trend is significant, because discharge variations follow at decadal climate cycle. The implication of these results is that the current best management practices and regulation put in place by the state legislature is having a positive effect on reducing the flux of nitrogen to the Neuse River estuary. During the next year we will continue to monitor non-point flux of nitrate into the reach adjacent to the NRWWTP and begin groundwater monitoring at the site in co-operation with DENR and the USGS to investigate the mechanism of transport. We will also expand the watershed nutrient mapping to the other RiverNet stations and smaller catchments.

All livestock operations generate fecal waste and manure management is an essential aspect of pork production. Regulations mandate permitting, training, design specifications, soil testing and livestock operation stream vegetation buffers. As the scale of pork production has increased to meet consumer demand communities have heightened their concern about the environmental impact of pork operations. Pork producers are actively working to reduce their overall water usage, land use and the carbon foot-print of their farming operations. Responsible environmental farm management has become an inherent necessity to maintain the sustainability of the pork industry and pork producers in the US have affirmed their obligation to safeguard our natural resources and manage pork production operations in a manner that protects natural environments and public health. The proposed studies support environmental management of pork production and address community concerns by facilitating accurate detection and effective attribution of the origin of fecal waste in surface waters and groundwater.

All livestock operations generate fecal waste and manure management is an essential aspect of pork production. Regulations mandate permitting, training, design specifications, soil testing and livestock operation stream vegetation buffers. As the scale of pork production has increased to meet consumer demand communities have heightened their concern about the environmental impact of pork operations. Pork producers are actively working to reduce their overall water usage, land use and the carbon foot-print of their farming operations. Responsible environmental farm management has become an inherent necessity to maintain the sustainability of the pork industry and pork producers in the US have affirmed their obligation to safeguard our natural resources and manage pork production operations in a manner that protects natural environments and public health. The proposed studies support environmental management of pork production and address community concerns by facilitating accurate detection and effective attribution of the origin of fecal waste in surface waters and groundwater.

The purpose of this project is to develop a low cost water quality continuous monitoring protocol to determine the state of water quality in rural agricultural watersheds, and to engage stakeholders including producers in watershed water quality monitoring activities. To accomplish this, we have formed two Watershed Alliance Groups in the Goshen and Stockhead Creek watersheds which consists of farmers and producers in Duplin County NC. We have instrumented critical points in the watersheds with Solinist Level Loggers that continuously measure water quality. Previous monitoring has shown that buffer quality determines stream nutrient concentrations. During this second year of monitoring the producers will grow back critical buffer areas and monitoring will document improvement in water quality associated with these efforts.

We propose to form a watershed producer’s workgroup in Stocking Head watershed, Duplin County NC and employ new monitoring techniques with Watershed Forensic Analysis. Watershed forensics is a new field that employs advanced GIS spatial analytical models to identify monitor and remediate N loading in multi land-use watersheds. Watershed forensics has taken a great leap forward in recent years with new GIS spatial analytical models using the USDA SSURGO national data base and the ArcInfo Soil Data Viewer toolbox. Current water quality monitoring methods that employ discrete grab samples cannot couple successfully with these new GIS analytical tools. Discrete sampling data commonly produces interpretation errors, especially with the absence of high discharge sampling. This can lead to erroneous loading conclusions and expensive remediation efforts that do not address nutrient water quality problems. New monitoring technologies including Optical and ISE (Ion Specific Electrode) analyzers can collect continuous hydrographic water quality data to couple with the new GIS watershed models. Once a problem is identified, these optical analyzers can spatially map nutrient concentrations to delineate nutrient sources on a watershed scale. If necessary, then clearly-defined and cost-effective remediation strategies can be employed to maintain water quality in multi-use agricultural watersheds.

Native freshwater mussels throughout North Carolina are in decline. Many mussel species that were once abundant and widely distributed throughout North Carolina river basins are now limited in number and distribution. Nearly concurrent with the decline has been the expansion of the range and abundance of Corbicula fluminea. This invasive species can be found in high densities in many streams where mussel populations once thrived. In other streams, high Corbicula densities are sympatric with relatively robust populations of native bivalves. We hypothesize that high densities of Corbicula may reduce available food resources for some species of native bivalves, and that the competitive inhibition of freshwater bivalves may be species specific. Complementary field and laboratory studies will be conducted to examine the effects of the presence of Corbicula on food resource availability and the growth of juvenile native freshwater mussels.

The purpose of this proposal is to determine the dominant mechanisms of nitrate transport to the river from the NRWWTP WAFs. This is a necessary first step to designing appropriate remediation strategies that will to protect Neuse River water quality from WAF NPS N flux. Preliminary studies in the riparian buffer areas at the site show that little N is transported through shallow groundwater in the riparian buffers. Surface water drainages (creeks) have nitrate concentrations that range from 10 to 80 mg/l N, and are geochemically and isotopically identical to shallow saprolite groundwaters. We propose to quantify the discharge and N flux in four creeks that drain the WAFs into the reach over a one-year period. RiverNet monitoring will continue to quantify N fluxes to the reach during this period funded by the WRRI Urban Consortium (City of Raleigh) and NCDENR (RiverNet). In addition, NCDENR Division of Aquifer Protection and the USGS, Raleigh Office has established a Piedmont Hydrogeological Research Observatory in the northwestern portion of the site. This observatory consists of 12 monitoring wells drilled from 40 to 380 ft depth in three well nests running from the ridge crest to the WAF buffer edge. 20 riparian wells have been installed by NCSU across the buffer to the river edge. These wells will measure the groundwater response and provide data for flowpath modeling during the proposed monitoring period. The importance of surface water drainage to groundwater N flux will be quantified. The effectiveness of remediation of surface water drainages with existing technologies can then be determined. Biosolid application at wastewater treatment plants is a common practice across the state and entire country, so the results and methods from this project are transferable. This project will address two Base Project Priorities in the Groundwater category and is a necessary first step to designing innovative groundwater remediation technologies intended to reduce the level of inorganic contaminants that discharge from groundwater to surface waters, which is a third Groundwater priority. This project has a significant number of cooperating agencies and leverages several existing resources. Remediation efforts to protect Neuse River water quality from WAF NPS N flux cannot proceed until the critical first step proposed here is completed.