@article{wilson_hayes_jones_eaves_wait_george_freeman_mize_fowlkes_currie_et al._2024, title={Lead occurrence in North Carolina well water: importance of sampling representation and collection techniques}, volume={19}, ISSN={["1748-9326"]}, DOI={10.1088/1748-9326/ad2b2c}, abstractNote={Abstract}, number={4}, journal={ENVIRONMENTAL RESEARCH LETTERS}, author={Wilson, Linnea and Hayes, Wesley and Jones, C. Nathan and Eaves, Lauren A. and Wait, Kory D. and George, Andrew and Freeman, Brady and Mize, Wilson and Fowlkes, Jon and Currie, Jefferson and et al.}, year={2024}, month={Apr} }
 @article{shiau_burchell_krauss_broome_birgand_2021, title={Carbon storage potential in a recently created brackish marsh in eastern North Carolina, USA (vol 127, pg 579, 2019)}, volume={168}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2021.106276}, journal={ECOLOGICAL ENGINEERING}, author={Shiau, Yo-Jin and Burchell, Michael R. and Krauss, Ken W. and Broome, Stephen W. and Birgand, Francois}, year={2021}, month={Oct} }
 @article{kurki-fox_burchell_2021, title={Characterizing ambient nutrient concentrations and potential warning levels for surface water in natural forested wetlands in the Piedmont and Coastal Plain of North Carolina, USA}, volume={172}, ISSN={["1872-6992"]}, url={http://dx.doi.org/10.1016/j.ecoleng.2021.106395}, DOI={10.1016/j.ecoleng.2021.106395}, abstractNote={Nearly thirty years ago the U.S. EPA directed states to begin developing water quality standards specific to wetlands; however, progress has been limited. This study presents an overview of ambient wetland water quality and the first step towards the development of numeric nutrient standards for forested wetlands in North Carolina. Water quality samples were collected in 16 natural wetlands across the state for three years. The sites span a range of anthropogenic disturbance. The data was combined with historical data collected at these and other sites from 2005 to 2013. Concentration levels in wetlands without significant anthropogenic disturbance are likely higher than streams for TN, TP, similar for NH 4 + , and likely lower than streams for NO 3 – -N. A method developed by the U.S. EPA to establish reference levels was modified to define draft nutrient warning levels that may indicate anthropogenic impacts. These warning levels were calculated as 0.06 mg/L, 0.14 mg/L, 0.34 mg/L and 2.8 mg/L for NO 3 – -N, NH 4 + -N, TP and TN, respectively. NO 3 – -N and NH 4 + -N concentrations were the best indicators of disturbance. Overall, despite the limitations imposed by the sampling frequency and inherent variability in wetland ecosystems, this research methodology presents a reasonable first attempt at defining nutrient warning levels for undisturbed natural forested wetlands in N.C., and may serve as a starting point in developing numeric nutrient criteria for wetlands. • A first step towards the development of nutrient concentration standards for natural wetlands. • Wetland standard concentration levels are likely higher than streams for TN, TP, similar for NH 4 + -N, and lower for NO 3 N. • Proposed warning levels for NO 3 – N and NH 4 + -N were the best indicators of disturbance. TN, ON, and TP were not robust indicators. • Results could help identify disturbance in natural forested wetlands in North Carolina.}, journal={ECOLOGICAL ENGINEERING}, publisher={Elsevier BV}, author={Kurki-Fox, J. Jack and Burchell, Michael R., II}, year={2021}, month={Dec} }
 @article{kurki-fox_burchell_vepraskas_broome_2021, title={Characterizing copper and zinc content in forested wetland soils of North Carolina, USA}, volume={193}, ISSN={["1573-2959"]}, url={https://doi.org/10.1007/s10661-021-09618-6}, DOI={10.1007/s10661-021-09618-6}, abstractNote={Wetlands are often located in landscape positions where they receive runoff or floodwaters, which may contain toxic trace metals and other pollutants from anthropogenic sources. Over time, this can lead to the accumulation of potentially harmful levels of metals in wetlands soils. To assess the potential risk of Cu and Zn buildup in wetland soils in North Carolina, soil data from 88 wetlands were analyzed. In a subset of 16 wetlands, more intensive sampling was conducted. Samples were analyzed for Mehlich 3 Cu and Zn, and a subset of the samples was analyzed for total Cu and Zn. Overall, Mehlich 3 Cu and Zn were low, with mean values of 0.9 mg/kg for Cu and 3.2 mg/kg for Zn. Warning levels for Mehlich 3 Zn were only exceeded in three of the 88 sites; elevated Mehlich Cu was not observed. Total Cu and Zn were also low, with only a few sites having elevated levels; however, there was not a strong linear relationship between Mehlich 3 and total metals. Mean levels of Mehlich 3 Cu and Zn in wetlands were much lower than for human-impacted upland soils and background threshold concentrations that might be indicative of disturbance were much lower than warning levels for agricultural soils. The very low mobile Zn and Cu in most of these wetlands indicated that these metals do not pose a risk to the biota in most North Carolina wetlands, but wetlands with a direct and significant anthropogenic source of metal contamination could be exceptions.}, number={12}, journal={ENVIRONMENTAL MONITORING AND ASSESSMENT}, publisher={Springer Science and Business Media LLC}, author={Kurki-Fox, J. Jack and Burchell, Michael R., II and Vepraskas, Michael J. and Broome, Stephen W.}, year={2021}, month={Dec} }
 @article{kamrath_burchell_kurki-fox_bass_2020, title={Impact of control structures on hydrologic restoration within the Great Dismal Swamp}, volume={158}, ISSN={["1872-6992"]}, url={http://dx.doi.org/10.1016/j.ecoleng.2020.106024}, DOI={10.1016/j.ecoleng.2020.106024}, abstractNote={The Great Dismal Swamp (GDS) is a 45,000-ha state and federally protected Coastal Plain peatland located on the border of North Carolina and Virginia that contains stands of Bald cypress and the globally threatened Atlantic white cedar. Centuries of drainage and logging have substantially altered the hydrology of the GDS, negatively affecting its ecosystem structure and function. To restore a seasonally flooded, saturated hydrologic regime to portions of the swamp, adjustable water control structures (WCS) were installed at strategic locations within existing drainage ditches. The objective of this study was to determine if the installation of the WCSs significantly altered the hydropatterns of two target restoration areas, resulting in hydrologic conditions comparable to nearby reference sites with desired forest communities. The water table (WT) was monitored for three years prior to WCS installation (pre-WCS) and three years after WCS installation (post-WCS). Comparison of WT data from the pre and post-WCS periods, using jurisdictional wetland criteria and empirical cumulative distribution functions (ECDFs), indicated increased saturated conditions within the target restoration areas following installation of the WCS. Paired Before-After Control-Impact (BACIP) statistical analysis revealed the WCS installation had a significant positive impact on WT levels in the target restoration areas relative to the reference sites. Hydrologic restoration will aid the effort to restore target forest communities within the swamp, reduce fire susceptibility, prevent peat oxidation, maintain carbon storage, and reduce non-target vegetation competition.}, journal={ECOLOGICAL ENGINEERING}, publisher={Elsevier BV}, author={Kamrath, Brock J. W. and Burchell, Michael R. and Kurki-Fox, J. Jack and Bass, Kris L.}, year={2020}, month={Dec} }
 @article{shiau_burchell_krauss_broome_birgand_2019, title={Carbon storage potential in a recently created brackish marsh in eastern North Carolina, USA}, volume={127}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2018.09.007}, DOI={10.1016/j.ecoleng.2018.09.007}, abstractNote={Carbon (C) sequestration through accumulated plant biomass and storage in soils can potentially make wetland ecosystems net C sinks. Here, we collected GHG flux, plant biomass, and litter decomposition data from three distinct vegetation zones (Spartina alterniflora, Juncus roemerianus and Spartina patens) on a 7-year-old created brackish marsh in North Carolina, USA, and integrate these data into an overall C mass balance budget. The marsh fixed an average of 1.85 g C m−2 day−1 through plant photosynthesis. About 41–46% of the fixed C remained in plants, while 18.4% of the C was decomposed and released back to the atmosphere as CO2 and CH4, and 8.6–13.2% of the decomposed C was stored as soil C. In all, this created marsh sequestered 28.7–44.7 Mg CO2 year−1 across the 14 ha marsh. Because the brackish marsh emitted only small amounts of CH4 and N2O, the CO2 equivalent emission of the marsh was −0.87 to −0.56 g CO2-eq m−2 day−1, indicating the marsh has a net effect in reducing GHGs to the atmosphere and contributes to cooling. However, resultant CO2 credit (through the increment of soil C) would be worth only $30.76–$47.90 USD per hectare annually, or $431–$671 per year for the project, which, coupled with other enhanced ecosystem services, could provide landowners with some additional economic incentive for future creation projects. Nevertheless, C mass balance determinations and radiative cooling metrics showed promise in demonstrating the potential of a young created brackish marsh to act as a net carbon sink.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Shiau, Yo-Jin and Burchell, Michael R. and Krauss, Ken W. and Broome, Stephen W. and Birgand, Francois}, year={2019}, month={Feb}, pages={579–588} }
 @article{messer_birgand_burchell_2019, title={Diel fluctuations of high level nitrate and dissolved organic carbon concentrations in constructed wetland mesocosms}, volume={133}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2019.04.027}, DOI={10.1016/j.ecoleng.2019.04.027}, abstractNote={Portable in situ ultraviolet-visual spectrometers, through high frequency water quality measurements, provide new insight into biogeochemical processes occurring within dynamic ecosystems. Nitrogen and carbon cycling were observed in two distinct wetland mesocosm environments during a two-year mesocosm study. Simulated drainage water was loaded into the mesocosms across seasons with target nitrate-N levels between 2.5 and 10 mg L−1. Nitrate-N and dissolved organic carbon concentrations in the water column were measured hourly with the spectrometer and calibrated with water quality grab samples. Prominent and unique diel cycles were observed in both nitrate-N and dissolved organic carbon readings from the spectrometer, which reveal biogeochemical processes in these systems are more complicated than typically considered in empirical models. Findings support the importance of utilizing high frequency monitoring to advance current knowledge of nitrogen and carbon processes occurring in treatment wetland ecosystems.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Messer, Tiffany L. and Birgand, François and Burchell, Michael R.}, year={2019}, month={Aug}, pages={76–87} }
 @book{burchell_hunt_2019, place={Raleigh, NC}, title={Natural and Constructed Wetlands in North Carolina: An Overview for Citizens}, url={https://content.ces.ncsu.edu/natural-and-constructed-wetlands-in-north-carolina}, number={AG-856}, institution={North Carolina Cooperative Extension Publication}, author={Burchell, Michael and Hunt, Bill}, year={2019}, month={Feb} }
 @article{kurki-fox_burchell_kamrath_2019, title={The Potential Long-Term Impacts of Climate Change on the Hydrologic Regimes of North Carolina’s Coastal Plain Non-Riverine Wetlands}, volume={62}, ISSN={2151-0040}, url={http://dx.doi.org/10.13031/trans.13437}, DOI={10.13031/trans.13437}, abstractNote={Highlights}, number={6}, journal={Transactions of the ASABE}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Kurki-Fox, J. Jack and Burchell, Michael R. and Kamrath, Brock J.}, year={2019}, pages={1591–1606} }
 @article{kamrath_burchell_cormier_krauss_johnson_2019, title={The Potential Resiliency of a Created Tidal Marsh to Sea Level Rise}, volume={62}, ISSN={2151-0040}, url={http://dx.doi.org/10.13031/trans.13438}, DOI={10.13031/trans.13438}, abstractNote={Abstract.}, number={6}, journal={Transactions of the ASABE}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Kamrath, Brock J. W. and Burchell, Michael R. and Cormier, Nicole and Krauss, Ken W. and Johnson, Darren J.}, year={2019}, pages={1567–1577} }
 @article{broome_craft_burchell_2019, title={Tidal Marsh Creation}, ISBN={["978-0-444-63893-9"]}, DOI={10.1016/B978-0-444-63893-9.00022-8}, abstractNote={Salt and brackish water tidal marshes are productive wetlands that provide ecosystem services including habitat, food energy for the estuarine food web, maintenance of water quality, storage of storm water, buffering storm waves and reducing shoreline erosion, carbon sequestration, and socioeconomic benefits. Loss of tidal marshes occurs as a result of dredging, filling, tidal restrictions, subsidence, sea level rise, and erosion. To mitigate those losses, techniques have been developed to create marshes on sites where they did not previously exist. The goal of tidal marsh creation is to provide habitats similar in structure and function to natural marshes. Because tides are the controlling abiotic factor of tidal marshes, the most critical requirement for creating new marshes is constructing sites at the correct elevation relative to the local tidal regime. Other important site-related factors that must be considered to insure successful marsh creation are slope, drainage, wave climate, currents, salinity, and soil physicochemical properties. Cultural practices that are important to establishment of vegetation include selection of native plant species, seed collection and storage, seedling production, site preparation, soil testing, fertilization, handling of transplants, timing of planting, plant spacing, control of undesirable invasive plants, and maintenance until the marsh is self-sustaining. The criteria used to define successful tidal marsh creation are often controversial. Plant communities may be equivalent to natural reference marshes in a few years, whereas other characteristics, such as soil organic matter, and numbers and species of benthic invertebrates require much longer to reach equivalence. When marsh creation technology is properly applied, tidal marshes can be created that provide many of the same ecosystems services that are provided by natural systems.}, journal={COASTAL WETLANDS: AN INTEGRATED ECOSYSTEM APPROACH, 2ND EDITION}, author={Broome, Stephen W. and Craft, Christopher B. and Burchell, Michael R.}, year={2019}, pages={789–816} }
 @book{poole_burchell_youssef_2018, place={Raleigh, NC}, title={Controlled Drainage – an important practice to protect water quality that can enhance crop yields}, url={https://content.ces.ncsu.edu/controlled-drainage}, number={AG-851}, institution={NC Cooperative Extension Publication}, author={Poole, C. and Burchell, M.R. and Youssef, M.}, year={2018} }
 @book{hartup_woodward_lord_burchell_doll_2018, place={Raleigh, NC}, title={Options for backyard stream repair}, url={https://content.ces.ncsu.edu/options-for-backyard-stream-repair}, number={AG-846}, institution={North Carolina Cooperative Extension Publication}, author={Hartup, W. and Woodward, M. and Lord, W. and Burchell, M.R. and Doll, B.}, year={2018} }
 @article{merriman_hathaway_burchell_hunt_2017, title={Adapting the relaxed tanks-in-series model for stormwater wetland water quality performance}, volume={9}, number={9}, journal={Water}, author={Merriman, L. S. and Hathaway, J. M. and Burchell, M. R. and Hunt, W. F.}, year={2017} }
 @book{osmond_burchell_2017, place={Raleigh, NC}, title={Agricultural riparian buffers}, url={https://content.ces.ncsu.edu/agricultural-riparian-buffers}, number={AG-439-38}, institution={North Carolina Cooperative Extension Publication}, author={Osmond, D.L. and Burchell, M.R.}, year={2017} }
 @article{etheridge_burchell_birgand_2017, title={Can created tidal marshes reduce nitrate export to downstream estuaries?}, volume={105}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2017.05.009}, DOI={10.1016/j.ecoleng.2017.05.009}, abstractNote={Constructed marshes have the potential to serve as a buffer between anthropogenic sources of nitrogen and nutrient sensitive estuaries. Yet, there is little information available on the reduction of nitrogen loads that created tidal marshes might provide. A 5.6 ha brackish marsh was constructed between row crop agricultural production and an estuary in North Carolina. Nitrate-N fluxes in and out of the marsh were monitored multiple times per hour for over a year to capture tidal and storm dynamics. Out of the five storms when most of the fluxes occurred, nitrate was retained in four (up to 42%), and released in the fifth, such that over the monitoring period the marsh retained 9% (40 kg) of the nitrate that entered. Nutrient addition tracer studies confirmed the potential nitrate retention (up to 45%) of the marsh. The residence time of water in the constructed brackish marsh was identified as the primary factor limiting nitrate retention through an examination of the factors that were related to percent nitrate retention. A retention model based on a mass transfer coefficient was applied during the storm events and tracer studies to further evaluate the marsh N retention capacity. The model adequately simulated the nitrate retention with calibrated mass transfer coefficients (0.1–0.56 m day−1) that fell within the range of those reported in literature for other systems. These results indicate that constructed tidal marshes can serve as substantial nitrate sinks and can be an integral part of overall plans to reduce the nutrient export to estuaries.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Etheridge, J. Randall and Burchell, Michael R., II and Birgand, François}, year={2017}, month={Aug}, pages={314–324} }
 @article{messer_burchell_bírgand_2017, title={Comparison of Four Nitrate Removal Kinetic Models in Two Distinct Wetland Restoration Mesocosm Systems}, volume={9}, ISSN={2073-4441}, url={http://dx.doi.org/10.3390/w9070517}, DOI={10.3390/w9070517}, abstractNote={The objective of the study was to determine the kinetic model that best fit observed nitrate removal rates at the mesocosm scale in order to determine ideal loading rates for two future wetland restorations slated to receive pulse flow agricultural drainage water. Four nitrate removal models were investigated: zero order, first order decay, efficiency loss, and Monod. Wetland mesocosms were constructed using the primary soil type (in triplicate) at each of the future wetland restoration sites. Eighteen mesocosm experiments were conducted over two years across seasons. Simulated drainage water was loaded into wetlands as batches, with target nitrate-N levels typically observed in agricultural drainage water (between 2.5 and 10 mg L−1). Nitrate-N removal observed during the experiments provided the basis for calibration and validation of the models. When the predictive strength of each of the four models was assessed, results indicated that the efficiency loss and first order decay models provided the strongest agreement between predicted and measured NO3-N removal rates, and the fit between the two models were comparable. Since the predictive power of these two models were similar, the less complicated first order decay model appeared to be the best choice in predicting appropriate loading rates for the future full-scale wetland restorations.}, number={7}, journal={Water}, publisher={MDPI AG}, author={Messer, Tiffany and Burchell, Michael and Bírgand, François}, year={2017}, month={Jul}, pages={517} }
 @article{messer_burchell_birgand_broome_chescheir_2017, title={Nitrate removal potential of restored wetlands loaded with agricultural drainage water: A mesocosm scale experimental approach}, volume={106}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2017.06.022}, DOI={10.1016/j.ecoleng.2017.06.022}, abstractNote={Wetland restoration is often conducted in Eastern U.S. coastal plain watersheds alongside agricultural lands that frequently export significant amounts of nitrogen in drainage water. Restoration plans that incorporate the addition of agricultural drainage water can simultaneously increase the success of achieving a target hydroperiod and reduce discharge of nitrogen to nearby surface water. The potential nitrogen removal effectiveness of two wetland restoration sites with such a restoration plan was evaluated in a two-year mesocosm study. Six large wetland mesocosms (3.5 m long × 0.9 m wide × 0.75 m deep) along with unplanted controls were used in this experiment. Three replicates of two soils that differed in organic matter and pH were planted with soft-stem bulrush (Schoenoplectus tabernaemontani) and allowed to develop in the two growing seasons prior to the study. Simulated drainage water was loaded into the mesocosms over eighteen batch studies across seasons with target nitrate-N levels between 2.5 to 10 mg L−1. Grab samples were collected from the water column and analyzed for nitrate-N, dissolved organic carbon, and chloride, along with other environmental parameters such as pH, water temperature, and soil redox. Seasonally, nitrogen and carbon within the wetland plants and soil were also measured. Multivariate statistical analyses were utilized to determine differences in nitrate-N reductions between treatments. Variables included carbon availability, temperature, antecedent moisture condition, nitrogen loading, and water pH. Contrary to the hypothesis that higher nitrate-N removal rates would be observed in the wetlands with higher organic matter, overall removal rates were higher in the wetland mesocosms containing Deloss soils (WET-Min) (maximum of 726 mg m−2 d−1) than those containing Scuppernong soil (WET-Org) (maximum of 496 mg m−2 d−1) and were dependent on daily NO3-N concentrations and season. Significant differences in NO3-N removal were found between seasons and soil types (α = 0.05), which helped to provide insight to the expected magnitude of nitrogen removal within these systems throughout the year, and potential mechanisms (i.e. denitrification vs. plant uptake) that will govern these removals.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Messer, Tiffany L. and Burchell, Michael R., II and Birgand, François and Broome, Stephen W. and Chescheir, George}, year={2017}, month={Sep}, pages={541–554} }
 @book{messer_burchell_birgand_broome_2017, place={Chapel Hill, NC}, title={Predicting Water Quality Impacts of Rerouting Drainage Water from the Pamlico Sound to Restored Wetlands}, number={480}, institution={Water Resources Institute of The University of North Carolina}, author={Messer, T.M. and Burchell, M.R. and Birgand, Francois and Broome, Steven}, year={2017} }
 @article{tilak_youssef_burchell_lowrance_williams_2017, title={Testing the riparian ecosystem management model (REMM) on a riparian buffer with dilution from deep groundwater}, volume={60}, number={2}, journal={Transactions of the ASABE}, author={Tilak, A. S. and Youssef, M. A. and Burchell, M. R. and Lowrance, R. R. and Williams, R. G.}, year={2017}, pages={377–392} }
 @article{messer_burchell_bohlke_tobias_2017, title={Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale N-15 enrichment tracer study}, volume={106}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2017.06.016}, abstractNote={Quantitative information about the fate of applied nitrate (NO3-N) in pulse-flow constructed wetlands is essential for designing wetland treatment systems and assessing their nitrogen removal services for agricultural and stormwater applications. Although many studies have documented NO3-N losses in wetlands, controlled experiments indicating the relative importance of different processes and N sinks are scarce. In the current study, 15NO3-N isotope enrichment tracer experiments were conducted in wetland mesocosms of two different wetland soil types at two realistic agricultural NO3-N source loads. The 15N label was traced from the source NO3-N into plant biomass, soil (including organic matter and ammonium), and N-gas constituents over 7–10 day study periods. All sinks responded positively to higher NO3-N loading. Plant uptake exceeded denitrification 2–3 fold in the low NO3-N loading experiments, while both fates were nearly equivalent in the high loading experiments. One to two years later, soils largely retained the assimilated tracer N, whereas plants had lost much of it. Results demonstrated that plant and microbial assimilation in the soil (temporary N sinks) can exceed denitrification (permanent N loss) in pulse-flow environments and must be considered by wetland designers and managers for optimizing nitrogen removal potential.}, journal={ECOLOGICAL ENGINEERING}, author={Messer, Tiffany L. and Burchell, Michael R. and Bohlke, J. K. and Tobias, Craig R.}, year={2017}, month={Sep}, pages={597–608} }
 @book{burchell_kamrath_bass_kurki-fox_2017, place={Raleigh, NC}, title={Wetland Restoration at Dismal Swamp State Park}, institution={NC Division of Parks and Recreation}, author={Burchell, M.R. and Kamrath, B.J. and Bass, K.L. and Kurki-Fox, J.}, year={2017}, month={May} }
 @book{burchell_rashash_2016, title={After the flood: Inspect, purge, and disinfect your well. North Carolina Cooperative Extension – Disaster Recovery}, url={https://content.ces.ncsu.edu/after-the-flood-inspect-purge-and-disinfect-your-well}, author={Burchell, M.R. and Rashash, D.}, year={2016} }
 @article{king_osmond_smith_burchell_dukes_evans_knies_kunickis_2016, title={Effects of Riparian Buffer Vegetation and Width: A 12-Year Longitudinal Study}, volume={45}, ISSN={0047-2425}, url={http://dx.doi.org/10.2134/jeq2015.06.0321}, DOI={10.2134/jeq2015.06.0321}, abstractNote={Agricultural contributions of nitrogen are a serious concern for many water resources and have spurred the implementation of riparian buffer zones to reduce groundwater nitrate (NO3). The optimum design for buffers is subject to debate, and there are few long‐term studies. The objective of this project was to determine the effectiveness over time (12 yr) of buffer types (trees, switchgrass, fescue, native, and a control) and buffer widths (8 and 15 m) by measuring groundwater NO3–N and dissolved organic carbon (DOC) trends. At the intermediate groundwater depth (1.5–2.1 m), NO3–N reduction effectiveness was 2.5 times greater (46 vs. 16%) for the wider buffer, and, regardless of width, buffer effectiveness increased 0.62% yr−1. Buffer vegetative type was never statistically significant. In the deep‐groundwater depth (2.1–3.5 m), there was no change in NO3–N removal over time, although the statistical interaction of width and vegetative type indicated a wide range of removal rates (19–82%). The DOC concentrations were analyzed at the field/buffer and buffer/stream sampling locations. Depending on location position and groundwater sampling depth, DOC concentrations ranged from 1.6 to 2.8 mg L−1 at Year 0 and increased at a rate of 0.13 to 0.18 mg L−1 yr−1 but always remained low (≤5.0 mg L−1). Greater DOC concentrations in the intermediate‐depth groundwater did not increase NO3–N removal; redox measurements indicated intermittent reduced soil conditions may have been limiting. This study suggests that riparian buffer width, not vegetation, is more important for NO3–N removal in the middle coastal plain of North Carolina for a newly established buffer.}, number={4}, journal={Journal of Environmental Quality}, publisher={Wiley}, author={King, S. E. and Osmond, D. L. and Smith, J. and Burchell, M. R. and Dukes, M. and Evans, R. O. and Knies, S. and Kunickis, S.}, year={2016}, month={Jul}, pages={1243–1251} }
 @book{burchell_thompson_broome_krometis_badgley_2016, place={Raleigh, NC}, title={Evaluation of Current and Potential Use to Improve Water Quality Trends and Protect Human Health. VT/NC State Regional Collaborative Proposal Planning and Development Grants}, journal={Constructed Wetlands to Polish Wastewater in Small Rural Communities}, institution={N.C. State University College of Agriculture and Life Sciences}, author={Burchell, M.R. and Thompson, T.W. and Broome, S.W. and Krometis, L.A. and Badgley, B.}, year={2016}, month={Sep} }
 @article{shiau_burchell_krauss_birgand_broome_2016, title={Greenhouse Gas Emissions from a Created Brackish Marsh in Eastern North Carolina}, volume={36}, ISSN={0277-5212 1943-6246}, url={http://dx.doi.org/10.1007/s13157-016-0815-y}, DOI={10.1007/s13157-016-0815-y}, number={6}, journal={Wetlands}, publisher={Springer Nature}, author={Shiau, Yo-Jin and Burchell, Michael R. and Krauss, Ken W. and Birgand, Francois and Broome, Stephen W.}, year={2016}, month={Sep}, pages={1009–1024} }
 @article{etheridge_birgand_burchell_2015, title={Quantifying nutrient and suspended solids fluxes in a constructed tidal marsh following rainfall: The value of capturing the rapid changes in flow and concentrations}, volume={78}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2014.05.021}, DOI={10.1016/j.ecoleng.2014.05.021}, abstractNote={Coastal tidal wetlands are perceived to provide nutrient dissipation services and serve as the final buffer between excess nutrient loads coming from nearby upland watersheds and sensitive estuarine waters. The construction and restoration of tidal marshes has the potential to benefit coastal waters. However, the water quality services of tidal wetlands have yet to be established with any certainty. This is in part due to the difficulty of monitoring these systems where flow and concentrations vary widely with tidal ebb and flood along with rainfall events mobilizing nutrients in pulses from upstream watersheds. In this article, we show over a period of 10 days following a rainfall event, the value of high temporal resolution data to characterize the complex nutrient and flow dynamics and to reliably calculate material balances in a created coastal marsh in North Carolina. Ultraviolet–visible spectrometers were used to obtain 15-min concentration data for nitrate, total Kjeldahl nitrogen, dissolved organic carbon, total suspended solids, phosphate, and total phosphorus. Our results show that a pulse of nitrate moved through the marsh from upstream agricultural production following the rainfall event and 25% (13 kg of 53 kg) of the nitrate was retained in the marsh over a period of 10 days. No other material showed a clear pulse from the upstream agricultural production. The marsh acted as a sink for total suspended solids (40 kg) and had near neutral mass balances for dissolved organic carbon, total Kjeldahl nitrogen, total phosphorus, and phosphate. Subsequent simulations indicated that different and erroneous results would have been obtained from 2-, 6- or 12-h sampling intervals. These results demonstrate, even on a short term basis, why high-frequency data acquisition is necessary in these tidal marsh systems to truly quantify their impact on water quality ecosystem services.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Etheridge, J. Randall and Birgand, François and Burchell, Michael R., II}, year={2015}, month={May}, pages={41–52} }
 @article{osburn_mikan_etheridge_burchell_birgand_2015, title={Seasonal variation in the quality of dissolved and particulate organic matter exchanged between a salt marsh and its adjacent estuary}, volume={120}, ISSN={2169-8953}, url={http://dx.doi.org/10.1002/2014JG002897}, DOI={10.1002/2014jg002897}, abstractNote={Abstract}, number={7}, journal={Journal of Geophysical. Research: Biogeosciences}, publisher={American Geophysical Union (AGU)}, author={Osburn, C.L. and Mikan, M.P. and Etheridge, J.R. and Burchell, M.R. and Birgand, F.}, year={2015}, month={Jul}, pages={1430–1449} }
 @article{tilak_burchell_youssef_lowrance_williams_2014, title={FIELD TESTING THE RIPARIAN ECOSYSTEM MANAGEMENT MODEL ON A RIPARIAN BUFFER IN THE NORTH CAROLINA UPPER COASTAL PLAIN}, volume={50}, ISSN={["1752-1688"]}, DOI={10.1111/jawr.12208}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Tilak, Amey S. and Burchell, Michael R., II and Youssef, Mohamed A. and Lowrance, Richard R. and Williams, Randy G.}, year={2014}, month={Jun}, pages={665–682} }
 @article{wiseman_burchell_grabow_osmond_messer_2014, title={GROUNDWATER NITRATE CONCENTRATION REDUCTIONS IN A RIPARIAN BUFFER ENROLLED IN THE NC CONSERVATION RESERVE ENHANCEMENT PROGRAM}, volume={50}, ISSN={["1752-1688"]}, DOI={10.1111/jawr.12209}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Wiseman, Jacob D. and Burchell, Michael R. and Grabow, Garry L. and Osmond, Deanna L. and Messer, T. L.}, year={2014}, month={Jun}, pages={653–664} }
 @book{burchell_birgand_broome_shiau_2014, place={Athens, GA}, title={Long-term study of Carbon Sequestration and Greenhouse Gas Emissions in Restored Salt Marshes}, institution={Piedmont-South Atlantic Coast Cooperative Ecosystem Studies Unit - USGS Ecosystems Mission Area}, author={Burchell, M.R. and Birgand, F. and Broome, S.W. and Shiau, Y.}, year={2014} }
 @article{etheridge_birgand_burchell ii_lepistö_rankinen_granlund_2014, title={Technical Note: Alternative in-stream denitrification equation for the INCA-N model}, volume={18}, ISSN={1607-7938}, url={http://dx.doi.org/10.5194/hess-18-1467-2014}, DOI={10.5194/hess-18-1467-2014}, abstractNote={Abstract. The Integrated Catchment model for Nitrogen (INCA-N) is a semi-distributed, process based model that has been used to model the impacts of land use, climate, and land management changes on hydrology and nitrogen loading. An observed problem with the INCA-N model is reproducing low nitrate–nitrogen concentrations during the summer growing season in some catchments. In this study, the current equation used to simulate the rate of in-stream denitrification was replaced with an alternate equation that uses a mass transfer coefficient and the stream bottom area. The results of simulating in-stream denitrification using the two different methods were compared for a one year simulation period of the Yläneenjoki catchment in Finland. The alternate equation (Nash–Sutcliffe efficiency = 0.61) simulated concentrations during the periods of the growing season with the lowest flow that were closer to the observed concentrations than the current equation (Nash–Sutcliffe efficiency = 0.60), but the results were mixed during other portions of the year. The results of the calibration and validation of the model using the two equations show that the alternate equation will simulate lower nitrate–nitrogen concentrations during the growing season when compared to the current equation, but promote investigation into other errors in the model that may be causing inaccuracies in the modeled concentrations.
                    }, number={4}, journal={Hydrology and Earth System Sciences}, publisher={Copernicus GmbH}, author={Etheridge, J. R. and Birgand, F. and Burchell II, M. R. and Lepistö, A. and Rankinen, K. and Granlund, K.}, year={2014}, month={Apr}, pages={1467–1473} }
 @article{etheridge_birgand_osborne_osburn_burchell_irving_2014, title={Using in situ ultraviolet-visual spectroscopy to measure nitrogen, carbon, phosphorus, and suspended solids concentrations at a high frequency in a brackish tidal marsh}, volume={12}, journal={Limnology and oceanography-methods}, author={Etheridge, J. R. and Birgand, F. and Osborne, J. A. and Osburn, C. L. and Burchell, M. R. and Irving, J.}, year={2014}, pages={10–22} }
 @article{etheridge_birgand_burchell_smith_2013, title={Addressing the Fouling of In Situ Ultraviolet-Visual Spectrometers Used to Continuously Monitor Water Quality in Brackish Tidal Marsh Waters}, volume={42}, ISSN={0047-2425}, url={http://dx.doi.org/10.2134/jeq2013.02.0049}, DOI={10.2134/jeq2013.02.0049}, abstractNote={The introduction of portable in situ ultraviolet-visual spectrometers has made possible the collection of water quality parameters at a high frequency in dynamic systems such as tidal marshes. The usefulness of this technology is inhibited by fouling of the instrument's optics. In this study, a spectrometer fitted with manufacturer-recommended compressed air optical cleaning was installed in a brackish marsh to determine if fouling interfered with measurements between bi-weekly servicing. During a 2-wk period, the absorbance measured in air at 220 nm increased from 9 to 549 m, indicating major fouling. An antifouling system was developed that reduced the time of exposure of the optics to stream water and used a pressurized fresh water cleaning. After implementation of the system, the absorbance in air increased to at most 63 m after 2 wk of data collection. The dramatic reduction in fouling will allow quality long-term data to be collected using this technology.}, number={6}, journal={Journal of Environment Quality}, publisher={American Society of Agronomy}, author={Etheridge, J. Randall and Birgand, François and Burchell, Michael R. and Smith, Brad T.}, year={2013}, pages={1896} }
 @book{burchell_hunt_price_2013, place={Raleigh, NC}, title={Dune infiltration systems for reducing stormwater discharge to coastal recreational beaches}, number={AG-781}, institution={North Carolina Cooperative Extension Publication}, author={Burchell, M.R. and Hunt, W.F. and Price, W.D.}, year={2013} }
 @book{fernandez_burchell_jennings_2013, place={Washington DC}, title={Field Evaluation of Restored Wetlands in North Carolina Using Floristic Indices, Rapid Assessments, and Environmental Parameters}, institution={Environmental Law Institute}, author={Fernandez, M.B. and Burchell, M.R. and Jennings, G.}, year={2013} }
 @article{price_burchell_hunt_chescheir_2013, title={Long-term study of dune infiltration systems to treat coastal stormwater runoff for fecal bacteria}, volume={52}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2012.12.008}, DOI={10.1016/j.ecoleng.2012.12.008}, abstractNote={Abstract The discharge of untreated stormwater runoff into recreational waters places swimmers at risk of contracting various illnesses and often results in beach closures or swimming advisories. In an effort to safeguard the public, two experimental Dune Infiltration Systems were installed beneath the sand dunes in Kure Beach, NC. The systems diverted stormwater from two existing beach outfalls, which drained 1.9 ha (4.7 ac) and 3.2 ha (8.0 ac) watersheds, into subsurface chambers for temporary storage and infiltration into the existing sand dunes. A 3-year study examined the long-term performance of the two systems during which 14,584 m 3 (515,046 ft 3 ) of stormwater was diverted into the dunes, with only 438 m 3 (15,457 ft 3 ) bypassing the systems, a nearly 97% capture rating. Enterococci concentrations in stormwater runoff from the watersheds exceeded the state's single sample maximum for Tier I waters (104 MPN/100 mL) in >70% of samples, with geometric means ≥278 MPN/100 mL. Groundwater enterococci concentrations tended to remain below the state limit (≤11% exceedance), with geometric means ≤7 MPN/100 mL. Groundwater monitoring in the control dune, with no direct input of stormwater, had a geometric mean of 5 MPN/100 mL and a 6% exceedance rate. The influences on the local water tables were temporary, as the water table would mound around the systems during infiltration events and dissipate to within pre-storm variations from the control within hours or up to approximately 2 weeks. The Dune Infiltration System appears appropriate for installation in small watersheds (}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Price, W.D. and Burchell, M.R., II and Hunt, W.F. and Chescheir, G.M.}, year={2013}, month={Mar}, pages={1–11} }
 @article{randall etheridge_lepistö_granlund_rankinen_birgand_burchell_2013, title={Reducing uncertainty in the calibration and validation of the INCA-N model by using soft data}, volume={45}, ISSN={0029-1277 2224-7955}, url={http://dx.doi.org/10.2166/nh.2013.039}, DOI={10.2166/nh.2013.039}, abstractNote={Process-based nutrient models are increasingly used to determine the impact of future changes in land use, agriculture production practices and climate on the quantity and timing of nutrients reaching surface waters. Calibration of catchment-scale models to observed conditions can be difficult due to parameter uncertainty and the heterogeneity of catchment processes. Soft data, i.e. knowledge of processes gained through experimentation, have been suggested as one method of reducing uncertainty and producing a more accurate model of the processes that occur in a catchment. In this work, the Integrated Catchment model for Nitrogen was calibrated and validated for the Yläneenjoki catchment in south-western Finland by incorporating soft data. The calibration for 2003–2008 produced an adequate model of the in-stream nitrate concentrations (R2 = 0.45, NS = 0.42). However, model validation using data from 1997–2002 showed that the simulated in-stream nitrate concentrations were above the observed concentrations throughout the entire period (R2 = 0.34, NS < 0). These results show that soft data can be used to constrain model parameters, resulting in a more accurate model of the catchment, but do not guarantee the best validation results as the simulated processes may not occur at the same time and rate as they did in the catchment.}, number={1}, journal={Hydrology Research}, publisher={IWA Publishing}, author={Randall Etheridge, J. and Lepistö, Ahti and Granlund, Kirsti and Rankinen, Katri and Birgand, François and Burchell, Michael R., II}, year={2013}, month={Jun}, pages={73–88} }
 @article{johnson_burchell_evans_osmond_gilliam_2013, title={Riparian buffer located in an upland landscape position does not enhance nitrate-nitrogen removal}, volume={52}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2012.11.006}, DOI={10.1016/j.ecoleng.2012.11.006}, abstractNote={Relatively narrow (<50 m) riparian buffers strategically reestablished in correct landscape positions have been shown to significantly reduce agricultural non-point source pollution to streams. Because of this, conservation programs have been established to encourage landowners to enroll lands near surface waters to improve water quality. Former cropland enrolled in a conservation program was evaluated to determine its effectiveness in reducing nitrate-nitrogen (NO3−-N) in shallow groundwater. This conservation buffer (CB) was up to 80 m wide and was planted with loblolly pine (Pinus taeda). It was situated upslope of an existing 30–60 m wide riparian hardwood forest buffer (EHB) located within the floodplain of an intermittent stream. Shallow groundwater NO3−-N, groundwater hydrology, total organic carbon, and soil redox potential were measured throughout both the CB and the EHB for 18 months. Groundwater NO3−-N concentrations, often 5–15 mg L−1 within the CB, were not significantly reduced from concentrations that entered from the agricultural field edge. However, a decrease in NO3−-N concentration was observed within the EHB (17–83%). The hydrology of the CB coupled with relatively low organic carbon contributed to a low denitrification potential and lack of NO3−-N reduction compared with the EHB. While the CB enrollment likely provided additional habitat benefits it did not appear to provide treatment of groundwater NO3−-N. It is our conclusion that landscape position is a more important defining variable for buffer site selection than buffer width if NO3−-N reduction is a primary goal.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Johnson, Sara R. and Burchell, Michael R., II and Evans, Robert O. and Osmond, Deanna L. and Gilliam, J. Wendell}, year={2013}, month={Mar}, pages={252–261} }
 @article{jarzemsky_burchell_evans_2013, title={The impact of manipulating surface topography on the hydrologic restoration of a forested coastal wetland}, volume={58}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2013.06.002}, abstractNote={A wetland, converted to agriculture in the mid-1970s, was restored to re-establish a non-riverine wet hardwood forest community in eastern North Carolina. Three surface techniques were implemented during construction to determine their effect on successfully restoring target wetland hydrology. The surface treatments, replicated within a randomized complete block design, were: plugging field ditches without altering the land surface (PLUG), plugging the field ditches and roughening the surface (ROUGH), and plugging the field ditches and removing the field crown (CR). Hydrologic conditions for the restoration and a nearby reference site were evaluated based on three years of monitoring data. Daily water table depths between the restoration and reference were within 11 cm on average. An initial evaluation found inconsistencies of treatment effect between blocks, and an as-built survey later confirmed surface elevations within Block 3 deviated from the intended design and was excluded from further analysis. Water table and outflow conditions for the remaining treatment plots and the reference were evaluated using several hydrologic criteria. The CR treatment was found to produce the wettest surface conditions and exported the lowest volume of outflow. For the majority of criterion considered, CR also produced significantly wetter conditions than the reference. The PLUG and ROUGH treatments produced similar hydrologic conditions and tracked closely with the median hydrologic conditions in the reference. Based on the results of this study and several others in low lying coastal areas, plugging pre-existing field ditches may be adequate to restore jurisdictional wetland hydrology and match reference hydrologic conditions. However, surface roughening is low cost method to increase surface storage and introduce microtopographic diversity. For many areas, the removal of existing field crown may be cost-prohibitive and produce wetter than desired conditions. Crown removal should be reserved for sites which have borderline historic wetland hydrologic characteristics.}, journal={ECOLOGICAL ENGINEERING}, author={Jarzemsky, Robert D. and Burchell, Michael R., II and Evans, Robert O.}, year={2013}, month={Sep}, pages={35–43} }
 @book{burchell_hunt_price_2012, place={Raleigh, NC}, title={Dune infiltration systems for reducing stormwater discharge into coastal waters}, number={EBAE-275-12}, institution={North Carolina State University Biological & Agricultural Engineering and North Carolina Cooperative Extension}, author={Burchell, M.R. and Hunt, W.F. and Price, W.D.}, year={2012} }
 @article{messer_burchell_grabow_osmond_2012, title={Groundwater nitrate reductions within upstream and downstream sections of a riparian buffer}, volume={47}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2012.06.017}, abstractNote={The objective of this study was to evaluate the water quality benefits provided by a buffer enrolled in the North Carolina Conservation Reserve Enhancement Program (NC CREP). A 5-year study was conducted on two distinct buffer sections along the same stream to evaluate the hydrology and attenuation of groundwater nitrate (NO3−-N) entering from nearby agricultural fields. The average buffer widths were 60 m (Section 1, upstream) and 45 m (Section 2, downstream). Three transects of groundwater monitoring well nests within each buffer zone were installed to monitor water quality and water table depths for 5 years. Mean groundwater NO3−-N concentrations at the 1.5 m depth decreased from 4.5 mg L−1 to 1.7 mg L−1 and from 12.9 mg L−1 to 1.4 mg L−1 in buffer Sections 1 and 2 respectively. These differences were significant in both buffer sections (α = 0.05), but the wider Section 1 received significantly less NO3−-N than did Section 2 (P < 0.0001). Groundwater NO3−-N loads were reduced by 0.003 kg m−2 yr−1 (76% reduction) at the 1.5 m depth, while in Section 2 these loads were reduced by 0.02 kg m−2 yr−1 (94% reduction) and 0.04 kg m−2 yr−1 (86% reduction) at the 1.5 m and 3 m depths, respectively. Topography, water table and redox measurements, nitrate to chloride ratios, and deep groundwater cation analyses, indicated both sections were suitable for denitrification to proceed. However, the position of the wider Section 1 buffer in the landscape limited the amount of NO3−-N contaminated groundwater that entered from the agricultural fields, and thus could have been designed to be narrower. The effectiveness of NO3−-N reduction in riparian buffer systems is dependent on multiple landscape and biogeochemical factors and not buffer width alone. Findings provide design guidance for conservation buffer program managers as related to the influence of buffer landscape position on groundwater nitrate reduction.}, journal={ECOLOGICAL ENGINEERING}, author={Messer, Tiffany L. and Burchell, Michael R., II and Grabow, Garry L. and Osmond, Deanna L.}, year={2012}, month={Oct}, pages={297–307} }
 @article{lenhart_hunt_burchell_2012, title={Harvestable Nitrogen Accumulation for Five Storm Water Wetland Plant Species: Trigger for Storm Water Control Measure Maintenance?}, volume={138}, ISSN={0733-9372 1943-7870}, url={http://dx.doi.org/10.1061/(asce)ee.1943-7870.0000550}, DOI={10.1061/(asce)ee.1943-7870.0000550}, abstractNote={AbstractAs the use of constructed storm water wetlands to treat storm water runoff becomes more frequent, strategies for maintaining or increasing their pollutant removal over time must be examined. One potential strategy is plant harvesting at the water surface to remove nutrients that would otherwise be deposited back into the wetland during senescence. This technical note presents a first look at this strategy from a storm water management perspective. Vegetation was harvested from two storm water wetlands located in Smithfield and Pactolus, North Carolina, to evaluate the ability of five wetland plant species to sequester nitrogen. Biomass samples were collected from the following species of emergent vegetation: Pontederia cordata (Pickerelweed), Saururus cernuus (Lizard Tail), Scirpus cyperinus (Wool Grass), Sagittaria latifolia (Arrowhead), and Schoenoplectus tabernaemontani (Softstem Bulrush). Samples were collected immediately prior to senescence in September and October 2007 and analyzed for nitr...}, number={9}, journal={Journal of Environmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={Lenhart, H. A. and Hunt, W. F. and Burchell, M. R.}, year={2012}, month={Sep}, pages={972–978} }
 @book{burchell_bass_chescheir_youssef_birgand_evans_2012, place={Raleigh, NC}, title={Hydrologic Impacts of Rerouting Pumped Agricultural Drainage Water Through a Historical and Restored Wetland System as Part of an Innovative Integrated Water Management System in Hyde County, NC}, institution={North Carolina Community Foundation}, author={Burchell, M.R. and Bass, K.L. and Chescheir, G.M. and Youssef, M. and Birgand, F. and Evans, R.O.}, year={2012}, month={Oct} }
 @book{shake_moorman_burchell_2012, place={Raleigh, NC}, title={Improving woody, early successional habitat patches for shrubland birds}, journal={NRCS Field Office Technical Guide}, institution={USDA NRCS Field Office}, author={Shake, C. and Moorman, C. and Burchell, M.R.}, year={2012} }
 @article{shake_moorman_burchell_2012, title={Improving woody, early successional habitat patches to benefit shrubland birds}, volume={17}, number={2}, journal={The Upland Gazette}, publisher={N.C. Wildlife Resource Commission}, author={Shake, C. and Moorman, C. and Burchell, M.R.}, year={2012}, pages={9–10} }
 @article{shake_moorman_riddle_burchell_2012, title={Influence of patch size and shape on occupancy by shrubland birds}, volume={14}, number={2}, journal={Condor}, author={Shake, C. S. and Moorman, C. E. and Riddle, J. D. and Burchell, M. R.}, year={2012}, pages={268–278} }
 @article{wu_osmond_graves_burchell_duckworth_2012, title={Relationships Between Nitrogen Transformation Rates and Gene Abundance in a Riparian Buffer Soil}, volume={50}, ISSN={0364-152X 1432-1009}, url={http://dx.doi.org/10.1007/s00267-012-9929-z}, DOI={10.1007/s00267-012-9929-z}, abstractNote={Denitrification is a critical biogeochemical process that results in the conversion of nitrate to volatile products, and thus is a major route of nitrogen loss from terrestrial environments. Riparian buffers are an important management tool that is widely utilized to protect water from non-point source pollution. However, riparian buffers vary in their nitrate removal effectiveness, and thus there is a need for mechanistic studies to explore nitrate dynamics in buffer soils. The objectives of this study were to examine the influence of specific types of soluble organic matter on nitrate loss and nitrous oxide production rates, and to elucidate the relationships between these rates and the abundances of functional genes in a riparian buffer soil. Continuous-flow soil column experiments were performed to investigate the effect of three types of soluble organic matter (citric acid, alginic acid, and Suwannee River dissolved organic carbon) on rates of nitrate loss and nitrous oxide production. We found that nitrate loss rates increased as citric acid concentrations increased; however, rates of nitrate loss were weakly affected or not affected by the addition of the other types of organic matter. In all experiments, rates of nitrous oxide production mirrored nitrate loss rates. In addition, quantitative polymerase chain reaction (qPCR) was utilized to quantify the number of genes known to encode enzymes that catalyze nitrite reduction (i.e., nirS and nirK) in soil that was collected at the conclusion of column experiments. Nitrate loss and nitrous oxide production rates trended with copy numbers of both nir and 16s rDNA genes. The results suggest that low-molecular mass organic species are more effective at promoting nitrogen transformations than large biopolymers or humic substances, and also help to link genetic potential to chemical reactivity.}, number={5}, journal={Environmental Management}, publisher={Springer Science and Business Media LLC}, author={Wu, Lin and Osmond, Deanna L. and Graves, Alexandria K. and Burchell, Michael R. and Duckworth, Owen W.}, year={2012}, month={Aug}, pages={861–874} }
 @book{bass_burchell_evans_hunt_line_seth-carley_2012, place={Raleigh, NC}, title={Stormwater wetlands for golf courses}, number={AG-765}, institution={North Carolina Cooperative Extension Publication}, author={Bass, K.L. and Burchell, M.R. and Evans, R.O. and Hunt, W.F. and Line, D. and Seth-Carley, D.}, year={2012} }
 @article{burchell_line_osmond_duckworth_moorman_hall_spooner_grabow_youssef_penrose_et al._2011, title={Conservation Reserve Enhancement Program (CREP) Environmental Monitoring}, journal={NCDENR - Division of Soil and Water}, author={Burchell, M.R. and Line, D. and Osmond, D. and Duckworth, O. and Moorman, C. and Hall, K. and Spooner, J. and Grabow, G. and Youssef, M. and Penrose, D. and et al.}, year={2011}, month={Oct} }
 @article{shake_moorman_burchell_2011, title={Cropland Edge, Forest Succession, and Landscape Affect Shrubland Bird Nest Predation}, volume={75}, ISSN={["0022-541X"]}, DOI={10.1002/jwmg.101}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Shake, Corey S. and Moorman, Christopher E. and Burchell, Michael R., II}, year={2011}, month={May}, pages={825–835} }
 @article{bright_burchell_hunt_price_2011, title={Feasibility of a Dune Infiltration System to Protect North Carolina Beaches from Fecal Bacteria Contaminated Storm Water}, volume={137}, ISSN={["0733-9372"]}, DOI={10.1061/(asce)ee.1943-7870.0000395}, abstractNote={Storm water ocean outfalls discharging into recreational waters pose a human health threat because of increased potential exposure to bacteria and other pathogens. The dune infiltration system (DIS) was designed and implemented at two ocean outfall sites in response to concerns by the North Carolina Department of Transportation and the town of Kure Beach, North Carolina The systems were designed to divert storm water runoff from 1.9 ha (4.7 acre) and 3.2 ha (8.0 acre) watersheds into the beach dunes. Following construction, data were collected from 25 storms during March through October 2006. The systems captured a combined total of nearly 1,800  m3 (63,500  ft3), or 95% of the influent storm water runoff—a significant reduction of runoff volume and peak flow discharging directly onto the beach (p<0.0001). Fecal coliform and enterococci concentrations were measured in the inflowing storm water runoff and groundwater downslope of the systems. Both groundwater bacteria concentrations near the systems were s...}, number={10}, journal={JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE}, author={Bright, Tiffany M. and Burchell, Michael R. and Hunt, William F. and Price, William}, year={2011}, month={Oct}, pages={968–979} }
 @book{price_burchell_hunt_chescheir_graves_2011, place={Raleigh, NC}, title={Long-term Water Quality Performance of a Coastal Dune Infiltration System}, institution={North Carolina Department of Transportation}, author={Price, W.D. and Burchell, M.R. and Hunt, W.F. and Chescheir, G.M. and Graves, A.}, year={2011}, month={Aug} }
 @article{moore_hunt_burchell_hathaway_2011, title={Organic nitrogen exports from urban stormwater wetlands in North Carolina}, volume={37}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2010.12.015}, abstractNote={Effluent organic nitrogen concentrations from seven constructed stormwater wetlands in North Carolina were examined to compare background organic nitrogen (ON) concentrations and the fraction of organic nitrogen relative to total nitrogen discharged. Seasonal influences on organic nitrogen concentrations were also examined. The median ON concentration from the stormwater wetlands was 0.78 mg l−1, and despite differences in wetland design and influent ON characteristics, outlet ON concentrations from all but one wetland were not significantly different. ON export from all stormwater wetlands was significantly less than untreated runoff entering the wetlands (p = 0.002). In addition, median organic:total nitrogen (ON:TN) ratios from stormwater wetlands (0.75) were significantly greater than from untreated urban runoff (0.66), comparing more closely to ON:TN ratios collected from a naturally occurring wetland and reported in the literature for natural landscapes. Seasonal differences in organic nitrogen concentrations were identified with significantly lower concentrations during the winter. Though stormwater wetlands will not (and perhaps should not be expected to) completely remove total nitrogen loads from runoff, these results suggest constructed wetlands can play a role in restoring the balance between organic and inorganic nitrogen forms closer to that of an undisturbed landscape. The presence of background organic nitrogen concentrations from stormwater wetlands similar to those from a naturally occurring wetland highlights the importance of choosing appropriate metrics (e.g., effluent concentrations) when assessing treatment performance.}, number={4}, journal={ECOLOGICAL ENGINEERING}, author={Moore, Trisha L. C. and Hunt, William F. and Burchell, Michael R. and Hathaway, Jon M.}, year={2011}, month={Apr}, pages={589–594} }
 @article{burchell_etheridge_evans_2011, title={Restoration of PC croplands: How long does it take to observe water quality improvement?}, volume={28}, number={1}, journal={Wetlands Science and Practice}, author={Burchell, M.R. and Etheridge, J.R. and Evans, R.O., Jr}, year={2011}, pages={28–32} }
 @article{taggart_heitman_vepraskas_burchell_2011, title={Surface shading effects on soil C loss in a temperate muck soil}, volume={163}, ISSN={0016-7061}, url={http://dx.doi.org/10.1016/j.geoderma.2011.04.020}, DOI={10.1016/j.geoderma.2011.04.020}, abstractNote={Histosols are a huge reservoir for C, covering < 1% of the world's land surface but storing up to 12% of total soil C. Thorough comprehension of factors controlling the rate of soil C loss from Histosols is critical for proper management of these C sinks. Two experiments evaluated how formerly cultivated, warm-climate Histosols undergoing wetland restoration respond to decreases in soil temperatures via vegetative shading, under different water table conditions. We compared temperature and soil CO2 efflux differences from intact soil cores under three levels of light reduction in a greenhouse: 0%, 70%, and 90%. Soil in full sun was consistently warmer and showed higher efflux rates than 70% and 90% shade treatments: 4.132, 3.438, and 2.054 μmol CO2 m−2 s−1, respectively. Shade treatments reached peak efflux rates at similar water potential, −2 to − 4 kPa. A field experiment subjected in-situ soil to full sun, 70% light reduction, and light reduction from naturally occurring herbaceous vegetation. Shade treatment effects on soil temperature and C mineralization were evident throughout the growing season. Vegetative shade effects on soil temperature were greatest in August and September when soil under vegetation was 5–11 °C cooler than unshaded soil. Soil CO2 efflux was correlated strongly with soil temperature; daily efflux rates were consistently highest from unshaded soil. Efflux across treatments showed a strong seasonal correlation to soil moisture, increasing as soil dried in response to water table decline. Soil water potential was unaffected by shade treatment, suggesting temperature effects were solely responsible for efflux differences between treatments. All results confirm that surface shading has a strong influence on soil temperatures and C mineralization rates. Management to enhance vegetative shading in wetland restoration projects may be an effective strategy for slowing soil C losses and promoting soil C sequestration when O2 is not limiting.}, number={3-4}, journal={Geoderma}, publisher={Elsevier BV}, author={Taggart, Matthew J. and Heitman, Joshua L. and Vepraskas, Michael J. and Burchell, Michael R.}, year={2011}, month={Jul}, pages={238–246} }
 @article{bright_hathaway_hunt_reyes_burchell_2010, title={Impact of Storm-Water Runoff on Clogging and Fecal Bacteria Reduction in Sand Columns}, volume={136}, ISSN={["1943-7870"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78651504665&partnerID=MN8TOARS}, DOI={10.1061/(asce)ee.1943-7870.0000280}, abstractNote={Storm-water runoff has been identified as a major cause of coastal water quality degradation. Storm-water outfalls, common in many coastal towns, convey bacteria and other pollutants into the ocean and estuaries. In an effort to minimize this impact, the Town of Kure Beach, North Carolina, installed Dune Infiltration Systems (DIS) at two storm-water outfalls to receive storm-water runoff and allow infiltration beneath the beach dunes. A laboratory column experiment was performed to supplement this installation and determine the potential hydraulic and bacterial removal efficiency of the sand comprising the Kure Beach dunes. Columns constructed using sand collected at different depths of the dune were used to analyze the affect of bacteria application on infiltration and to examine the changes in bacteria removal that occur as infiltration rates are affected by bacteria-laden water application. Sand columns were loaded over a 60-day period with either bacteria-free storm water or storm water spiked with Es...}, number={12}, journal={JOURNAL OF ENVIRONMENTAL ENGINEERING}, author={Bright, T. M. and Hathaway, J. M. and Hunt, W. F., III and Reyes, F. L., III and Burchell, M. R., III}, year={2010}, month={Dec}, pages={1435–1441} }
 @book{price_burchell_chescheir_hunt_2010, place={Chapel Hill, NC}, title={Reducing Bacterial Loads from Ocean Outfalls Using Dune Infiltration Systems}, institution={University of North Carolina Water Resources Research Institute (UNC-WRRI)}, author={Price, W.D. and Burchell, M.R. and Chescheir, G.M. and Hunt, W.F.}, year={2010}, month={Oct} }
 @book{burchell_bass_2010, place={Wilmington, NC}, title={Stormwater BMPs and LID Measures to Protect Coastal Waters Near Eagle Point Golf Club}, institution={New Hanover County Planning Department}, author={Burchell, M.R. and Bass, K.L.}, year={2010}, month={Jan} }
 @book{burchell_hunt_bass_wright_2010, place={Raleigh, NC}, title={Stormwater wetlands construction guidance}, number={AGW-588-13}, institution={North Carolina State University Extension Service}, author={Burchell, M.R. and Hunt, W.F. and Bass, K.L. and Wright, J.D.}, year={2010} }
 @inproceedings{wright_hunt_burchell, ii_perrin_mccoy_2009, title={Implementation and Performance of Stormwater Best Management Practice Retrofits in Wilmington, NC}, ISBN={9780784410363}, url={http://dx.doi.org/10.1061/41036(342)536}, DOI={10.1061/41036(342)536}, abstractNote={Burnt Mill Creek, located within downtown Wilmington, NC, is on the EPA's 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 multi-family residential areas, recreational parks, and commercial and industrial areas. Restoration efforts are multiplying in Burnt Mill Creek as a result of passionate involvement from local community leaders, and partnerships with state organizations. The Watershed Education for Communities and Local Officials (WECO) coordinated a partnership, with NCSU BAE, the City of Wilmington, 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. Community involvement has led to several retrofit BMP opportunities, including pervious pavement and rain gardens at a local YMCA, two bioretention cells installed in the parking lot at Port City Java's corporate headquarters, a stormwater wetland in a city owned communal area, and several residential scale rain gardens in an urban low income community. Twelve rain gardens and twenty four rain barrels were installed at citizen's private residences in an urban neighborhood in downtown Wilmington. Although restoration takes time, momentum continues to build in the Burnt Mill Creek watershed as resources are devoted to thoughtful education and engagement with the public.}, booktitle={World Environmental and Water Resources Congress 2009}, publisher={American Society of Civil Engineers}, author={Wright, J. D. and Hunt, W. F. and Burchell, II, M. R. and Perrin, C. A. and McCoy, E. R.}, year={2009}, month={May} }
 @book{evans_burchell_vepraskas_broome_shear_bass_grabow_2009, place={Raleigh, NC}, title={North River Wetlands Restoration Research}, number={Contract AW03007}, institution={North Carolina Ecosystem Enhancement Program}, author={Evans, R.O. and Burchell, M.R. and Vepraskas, M. and Broome, S.W. and Shear, T. and Bass, K.L. and Grabow, G.}, year={2009}, month={Aug} }
 @inproceedings{wright_hunt_burchell, ii_perrin_2008, title={Implementation and Performance of Stormwater Best Management Practice Retrofits in Wilmington, NC}, ISBN={9780784409763}, url={http://dx.doi.org/10.1061/40976(316)647}, DOI={10.1061/40976(316)647}, abstractNote={Text: Burnt Mill Creek, located within downtown Wilmington, NC, is on the EPA’s 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. Restoration efforts are multiplying in Burnt Mill Creek as a result of passionate involvement from local community leaders, and partnerships with state organizations. The Watershed Education for Communities and Local Officials (WECO) coordinated a partnership, with NCSU BAE, the City of Wilmington, 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. Community involvement has led to several retrofit BMP opportunities, including pervious pavement and rain gardens at a local YMCA, a stormwater wetland at a townhome community, two bioretention cells installed in the parking lot at Port City Java’s corporate headquarters, and a stormwater wetland in a city owned communal area. A crusher run gravel parking lot at the YMCA was a substantial source of sediment into Burnt Mill Creek. The gravel was replaced with porous concrete, two rain gardens, and grassed landscaping. A stormwater wetland was installed in a townhome community to treat a 5 acre drainage area. Runoff from the parking lot at the Port City Java headquarters was intercepted by a sod bioretention area. A stormwater wetland was constructed to treat a 5.5 acre watershed that drains through City owned open space adjacent to Burnt Mill Creek. Monitoring conducted at each site and in the watershed will help determine the effects of the bmp’s individually and on the watershed as a whole. Although restoration takes time, momentum continues to build in the Burnt Mill Creek watershed as resources are devoted to thoughtful education and engagement with the public.}, booktitle={World Environmental and Water Resources Congress 2008}, publisher={American Society of Civil Engineers}, author={Wright, J. D. and Hunt, W. F. and Burchell, II, M. R. and Perrin, C. A.}, year={2008}, month={May} }
 @inproceedings{burchell_hunt, iii_chescheir_2008, title={Reducing Stormwater Bacteria Loads to North Carolina Ocean Recreational Areas Using a Dune Infiltration System}, ISBN={9780784409763}, url={http://dx.doi.org/10.1061/40976(316)34}, DOI={10.1061/40976(316)34}, abstractNote={Coastal towns traditionally discharge stormwater containing bacteria and pathogens to the ocean via ocean outfalls, increasing the potential for serious diseases to recreational swimmers. To combat this risk, an innovative coastal BMP, a Dune Infiltration System (DIS), was designed and installed at two locations in Kure Beach, N.C. to divert stormwater from outfalls into the dunes. Post-construction monitoring of these systems during 25 storm events in 2006 showed that this design was economically and technically feasible, because 97% of the stormwater was diverted into the dunes, the dunes remained structurally stable, and Enterococcus concentrations entering from the outfalls were reduced by over 97%. However bacterial transport surrounding the system remained poorly understood, which limited the certainty at which this system could be recommended for further implementation. Therefore, a series of additional water table and water quality wells were installed at each of the systems, and in a nearby control dune, during the summer of 2007. After six-months, bacterial concentrations in the groundwater at the dune-beach interface near the dune infiltration sites are similar to that of the control area. Introduction As populations increase near our beaches, new development and increased imperviousness generates more stormwater. Coastal towns traditionally discharge stormwater containing, among other pollutants, bacteria and pathogens to the ocean via ocean outfalls. More development equates to more stormwater flowing into the oceans under current management techniques, increasing the potential for serious diseases to recreational swimmers. The Town of Kure Beach, NC has a number of stormwater outfalls that discharge on to the beach, sometimes directly flowing into the ocean with little infiltration into the sand. Stormwater samples collected from two outfalls draining from the town had Enterococcus levels that ranged from 1.3 cm/hr). The dunes in Kure Beach have a relatively high elevation (~ 5.0 m (16.5 ft) above MSL), while the groundwater elevation, though subject to tidal influences, is relatively low (0.31.0 m (1-3 ft)). Coupled with high infiltration rates common with beach sand, this makes for an ideal location for infiltration. Two of these systems were installed in February 2006 to capture stormwater runoff from the L Ave. outfall (1.9 ha. (4.7 acre) watershed) and M Ave. outfall (3.2 ha (8.5 acre) watershed). Both watersheds had similar mixed urban/residential development. The designed DIS for L Ave. required 12 chambers and was approximately 30 m (100 ft) long, while the M Ave. system required 22 chambers and was approximately 60 m (200 ft) long. Stormwater was diverted into each system form the outfalls in a subsurface concrete vault. These systems were installed 50 m (160 ft) from the mean high tide line. Figure 1 shows the system at L Ave. (known as Site L) during installation, and the condition of the dunes 15 months following installation and replanting of the dune vegetation. Additional details of the design procedure and installation of the DIS can be found in Bright (2006) and Burchell et al. (2007). Following storm event data collection in 2006, the system appeared to be very efficient in reducing stormwater flow and bacterial transport to the ocean areas. Stormwater exported from the two outfalls combined was reduced by 97%, with brief overflows occurring at the M Ave. site (known as Site M) during only 5 of 25 storms measured. Nearly 3000 m (790,00 gallons) of stormwater were diverted into the dunes rather than discharging directly on the beach. The groundwater Enterococcus levels measured 8 m (25 ft) downslope of the systems ranged from 5 CFU/100 ml to 64 CFU/100 ml with a median of 5 CFU/100 ml at Site L, and ranged from 5 CFU/100 ml to 2,005 CFU/100 ml with a median of 26 CFU/100ml at Site M. These groundwater samples were significantly less than the stormwater Enterococcus concentrations that would have been exported from the outfalls (p<0.01). None of the groundwater samples at Site L exceeded the state’s Enterococcus standard, but six samples from the groundwater at Site M did (Bright, 2006; Burchell et al., 2007). The initial study of the system was considered a demonstration of a potential new BMP, so post-construction monitoring was to assess the feasibility of the practice. While the initial results of that level of monitoring appeared promising, the fate and transport of the bacteria in the dunes beneath the DIS was still not clearly understood. The increased groundwater Enterococcus concentrations observed particularly at Site M, the larger system, made it imperative that a more rigorous monitoring procedure be employed to determine if the DIS would have any negative Figure 1. The Dune Infiltration System at Site L during installation (left) and the well vegetated dunes 15 months after installation (right). effects as the groundwater migrated towards the ocean. Groundwater samples in the first study were collected only 8 m (25 ft) down-gradient of the DIS, leaving approximately 40 m (130 ft) of dune and beach for the groundwater to travel through before encountering the surf zone. We hypothesized early that bacteria levels near the system would likely be elevated, but would decrease as it moved laterally towards the beach. In May 2007, research at the site was intensified to test this hypothesis by studying the groundwater hydrology and bacteria levels in transects that extended from above the DIS system to the dune-beach interface, with added monitoring of a nearby dune system to serve as an experimental control. This paper will serve to summarize preliminary results obtained during the first 6 months of this study. Methods During July 2007, additional groundwater wells were installed up and downgradient of the systems to measure groundwater fluctuations and bacterial concentrations resulting from infiltration of stormwater into the DISs. Based on previous water table measurements and dune elevations that decreased as much as 2 m (6 ft) from Atlantic Avenue towards the beach, wells were installed 4-6 m (12-18 ft) deep. Wells were 5 cm (2 in) in diameter, and the bottom 0.6 m (2 ft) and 3 m (10 ft) of the water quality and water table wells respectively were screened and protected with two layers of drain sock. Each DIS had 1 transect of water table wells, and two transects of water quality wells downslope of the system, with one water table and water quality well upslope of the system. Figure 2 shows a general schematic of the DIS and the surrounding well locations. Additionally, wells were installed at upslope, mid, and at the dune-beach interface positions of a control dune. Water table measurements were logged continuously at 20 minute intervals with INFINITY (Infinities USA, Inc.) and HOBO (Onset Computer Corporation) water level recorders. Wells were surveyed initially and measured manually monthly to convert the readings into water level elevations. Rainfall was recorded using a tipping bucket rain gage and a HOBO event logger (ONSET Computer Corporation). 1 The use of trade names does not imply endorsement by North Carolina State University or ASCE. Figure 2. Schematic of the Dune Infiltration System and a general layout of the water table and water quality sampling wells. Water quality samples collected were delivered within EPA recommended holding times and temperature, and analyzed for Enterococcus (ASTM method #D6503-99) by NC Shellfish Sanitation and Recreational Water Section Laboratory in Wilmington, N.C. Stormwater samples entering each DIS were collected using an ISCO 6712 Portable Sampler connected to an ISCO 730 Bubbler Module (Teledyne Isco, Inc.) that used stage, slope and roughness of the pipe to calculate flow volumes and trigger the sampler. Groundwater samples were collected monthly with disposable bailers following purging of 3 well volumes. Results and Discussion Analysis of six-months of data collected at the DIS sites have revealed a number of interesting trends regarding groundwater hydrology and bacterial transport in the dune systems. Groundwater Hydrology Beneath the Dunes During the initial study there were only a few wells located about 8 m downslope of the systems, and there was no real strong water table response observed following infiltration events from smaller storms that would have indicated the extent of groundwater mounding beneath the systems. With the additional wells installed closer to the system, the water table response near the system has become more clear. Figure 3 shows and example of the water table response at Site L, the smaller system collecting stormwater from 1.9 ha (4.7 ac) watershed. Mounding beneath the DIS is easily observed following a 3.3 cm (1.3 in) rainfall event on December 16. X X X X X}, booktitle={World Environmental and Water Resources Congress 2008}, publisher={American Society of Civil Engineers}, author={Burchell, M. R. and Hunt, III, W. F. and Chescheir, G. M.}, year={2008}, month={May} }
 @book{perrin_wright_hunt_beggs_mallin_burchell_2008, title={Restoring the Burnt Mill Creek Watershed through Stormwater Management and Community Development}, number={FY04 EPA 319 Grant. NCDENR Contract EW05023}, author={Perrin, C. and Wright, J.D. and Hunt, W.F. and Beggs, P. and Mallin, M. and Burchell, M.R.}, year={2008}, month={Aug} }
 @inproceedings{burchell_skaggs_evans_lee_broome_2007, title={Addition of Organic Matter to Agricultural Ditch Soils to be Used as Constructed Wetlands for Nitrate Treatment}, ISBN={9780784409275}, url={http://dx.doi.org/10.1061/40927(243)233}, DOI={10.1061/40927(243)233}, abstractNote={A wetland mesocosm experiment was conducted in eastern N.C. to determine if organic matter (OM) addition to soils existing in ditches that are to be retrofitted into constructed wetlands would improve NO3–-N treatment. Not all soils are suitable for wetland substrate, so OM addition can provide a carbon and nutrient source to the wetland early in its development to enhance denitrification and biomass growth. Batch studies, with various initial NO3–-N concentrations were conducted in surface-flow wetland mesocosms. The results indicated that increasing the organic matter content of a Cape Fear loam soil from 50 g kg–1 (5% d.w.) to 110 g kg–1 (11% d.w.) enhanced NO3–-N wetland treatment efficiency in spring and summer batch studies, but increases to 160 g kg–1 (16% d.w.) OM did not. Increased OM addition and biosolids to the soil significantly increased biomass growth in the second growing season, when compared to no OM addition. Based on the first-order kinetic constants for nitrate reduction calculated from these mesocosm studies, increased OM in the substrate will reduce the area required for wetlands constructed in ditches to treat nitrate-laden drainage water.}, booktitle={World Environmental and Water Resources Congress 2007}, publisher={American Society of Civil Engineers}, author={Burchell, M. R. and Skaggs, R. W. and Evans, R. O. and Lee, C. R. and Broome, S. W.}, year={2007}, month={May} }
 @inproceedings{bass_evans_burchell_2007, title={Comparing Design Methods for Restoring Small Streams in NC's Coastal Plain}, ISBN={9780784409275}, url={http://dx.doi.org/10.1061/40927(243)235}, DOI={10.1061/40927(243)235}, abstractNote={Two stream restoration projects were recently designed and constructed in the coastal plain of NC. Several popular design approaches were implemented to develop plan parameters. Traditional engineering methods, natural channel design methods, and analytical approaches were utilized. The results of each approach were compiled for comparison and to improve design confidence. This paper includes a description of the methods employed, the limitations encountered, and an evaluation of the results. Each method presents challenges in terms of data collection, effort, and the experience required. Information on these limitations should be incorporated in design approach and application decisions. Based on initial findings, it appears that design differences for small streams with relatively stable watersheds may not exceed expected variability. However, this may not be the case for larger streams as differences increased with watershed size and complexity. It is suggested that completing similar initial estimates will improve design decisions, confidence, and reduce risk. As the science of stream restoration progresses, more quantitative comparisons of this type will provide designers with the information needed to guide complex approach decisions.}, booktitle={World Environmental and Water Resources Congress 2007}, publisher={American Society of Civil Engineers}, author={Bass, K. L. and Evans, R. O. and Burchell, M. R.}, year={2007}, month={May} }
 @inproceedings{burchell_line_hunt, iii_wright_2007, title={Conversion of a Drainage Ditch to Constructed Wetlands to Treat Stormwater Runoff}, ISBN={9780784409275}, url={http://dx.doi.org/10.1061/40927(243)246}, DOI={10.1061/40927(243)246}, abstractNote={A drainage ditch near Laney High School in Wilmington, N.C., designed to collect runoff from athletic fields and parking lots and deliver it to Smith Creek, was converted to a constructed wetland in August 2005: The approximately 0.1 ha wetland collects and treats drainage water from a 12 ha watershed, 2.4 ha of which is impervious surface. The wetland was designed with a variety of elevation features and planted with over 15 species of wetland plants, to encourage sedimentation, biogeochemical transformations of nutrients associated with runoff, and ecological diversity. Retention times are estimated to be 3–4 days. As of summer 2006, the wetland was vegetated and on-line. Preliminary nutrient data indicate a 50% reduction in TN and TP concentrations, and a 40% reduction in TSS.}, booktitle={World Environmental and Water Resources Congress 2007}, publisher={American Society of Civil Engineers}, author={Burchell, M. R. and Line, D. and Hunt, III, W. F. and Wright, J.}, year={2007}, month={May} }
 @book{burchell_hunt_2007, place={Wilmington, NC}, title={Implementation of Two Priority Stormwater Best Management Practice (BMP) Projects for the New Hanover County, NC Local Watershed Plan}, institution={New Hanover County Planning Department}, author={Burchell, M.R. and Hunt, W.F.}, year={2007}, month={Apr} }
 @book{burchell_hunt_bright_2007, place={Raleigh, NC}, title={Kure Beach Dune Infiltration System}, number={Project 2005-29}, institution={NCDOT Research and Analysis Group}, author={Burchell, M.R. and Hunt, W.F. and Bright, T.M.}, year={2007}, month={Jul} }
 @article{evans_bass_burchell_hinson_johnson_doxey_2007, title={Management alternatives to enhance water quality and ecological function of channelized streams and drainage canals}, volume={62}, number={4}, journal={Journal of Soil & Water Conservation}, author={Evans, R. O. and Bass, K. L. and Burchell, M. R. and Hinson, R. D. and Johnson, R. and Doxey, M.}, year={2007}, pages={308–320} }
 @book{hunt_burchell_wright_bass_2007, place={Raleigh, NC}, title={Stormwater wetland design update}, number={AGW-588-12}, institution={North Carolina State University Extension Service}, author={Hunt, W.F., III and Burchell, M.R. and Wright, J.D. and Bass, K.L.}, year={2007} }
 @article{burchell_skaggs_lee_broome_chescheir_osborne_2007, title={Substrate organic matter to improve nitrate removal in surface-flow constructed wetlands}, volume={36}, ISSN={["0047-2425"]}, DOI={10.2134/jeq2006.0022}, abstractNote={ABSTRACT}, number={1}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Burchell, Michael R., II and Skaggs, R. Wayne and Lee, Charles R. and Broome, Steven and Chescheir, George M. and Osborne, Jason}, year={2007}, pages={194–207} }
 @article{burchell_skaggs_chescheir_gilliam_arnold_2005, title={Shallow subsurface drains to reduce nitrate losses from drained agricultural lands}, volume={48}, DOI={10.13031/2013.18518}, abstractNote={Nitrate losses from subsurface drainage systems remain an important environmental concern. Data were collected 
from two drainage systems near Plymouth, North Carolina, to evaluate the effect of subsurface drain depth on nitrate-nitrogen 
(NO3 
--N) losses. Drains in plot 1 were 1.5 m deep and 25 m apart, and drains in plot 2 were 0.75 m deep and 12.5 m apart. 
Both plots received swine wastewater applications. Overall, the shallow drainage system had 42% less outflow than the 
deeper drainage system. Lower NO3 
--N concentrations were observed in the shallow groundwater beneath the shallow 
drainage plots as a result of higher water tables and likely increased denitrification. However, NO3 
--N concentrations in the 
drainage water from the shallow drains were not reduced. On average, NO3 
--N export from the shallow subsurface drains 
was 8 kg ha-1 in 2001 and 27 kg ha-1 in 2002. Nitrate export from the deeper drains was 6 kg ha-1 in 2001 and 37 kg ha-1 
in 2002. Decreased export observed in 2002 from the shallow subsurface drainage system was significant at the 10% level, 
but not for the entire 21-month period. Longer-term field studies, which incorporate variable climatological events, are 
needed to conclude whether shallower drain depth will reduce NO3 
--N export from subsurface drainage systems.}, number={3}, journal={Transactions of the ASAE}, author={Burchell, Michael and Skaggs, R. W. and Chescheir, G. M. and Gilliam, J. W. and Arnold, L. A.}, year={2005}, pages={1079–1089} }
 @article{burchell_skaggs_chescheir_2004, title={Can shallow drains reduce nitrate losses?}, volume={30}, journal={Drainage Contractor}, author={Burchell, M.R. and Skaggs, R.W. and Chescheir, G.M.}, year={2004} }
 @book{sturgis_lee_banks_burchell_johnson_2001, place={Vicksburg, MS}, title={Evaluation of Manufactured Soil Using Dredged Material from New York/New Jersey Harbor Newton Creek Site. Phase 1: Greenhouse Bench-Scale Test}, url={http://dx.doi.org/10.21236/ada397459}, DOI={10.21236/ada397459}, abstractNote={Abstract : Manufactured soil/beneficial reuse of dredged material is a potential strategy/alternative for long-term confined disposal. The development of a manufactured topsoil product will allow the U.S. Army Corps of Engineers to remove dredged material from confined disposal facilities (CDFs). This will increase the capacity of the CDFs and eliminate the shortage of CDFs for dredged material storage. In addition, manufactured topsoil from dredged material will potentially result in a product that can be reused in ways that are beneficial to the environment. Manufactured soil can be used for topsoil, bagged soil, landscaping, superfluid site cover, mining site cover, and landfill cover. The U.S. Army Engineer Research and Development Center, Vicksburg, MS, has established Cooperative Research and Development Agreements to develop technology for the manufacture of topsoil using sediment/dredged material (decontaminated and contaminated), cellulose waste materials, and nutrient-rich organic waste materials. The recycled soil manufacturing technology (RSMT) allowed the development of fertile topsoil that could be used in a beneficial, productive, and environmentally sound manner. In addition, the RSMT will provide an alternative to conventional disposal of the nation's waste/resource material from the Metcalf and Eddy process (decontaminated New York/New Jersey Harbor dredged material via solvent extraction) and untreated dredged material collected directly from the New York/New Jersey Harbor Newton Creek Site. Screening tests included proprietary blends with a range of dredged material content, a range of cellulose, and animal derived biosolids.}, number={ERDC/EL TR-01-35ERDC/EL TR-01-35}, institution={Defense Technical Information Center, U.S. Army Engineer Research and Development Center}, author={Sturgis, Thomas C. and Lee, Charles R. and Banks, Henry C., Jr. and Burchell, Michael R., II and Johnson, Kervin}, year={2001}, month={Oct} }