@article{lisenbee_hathaway_negm_youssef_winston_2020, title={Enhanced bioretention cell modeling with DRAINMOD-Urban: Moving from water balances to hydrograph production}, volume={582}, ISSN={["1879-2707"]}, DOI={10.1016/j.jhydrol.2019.124491}, abstractNote={Bioretention systems have become a leading stormwater control measure for mitigating urban hydrology. Although these systems have performed well in many site-scale field studies, less investigation has been directed toward effectively modeling these systems. This is critical, as modeling of bioretention systems provides an avenue for evaluating their effectiveness prior to devoting time and resources into installation. Many hydrologic models capable of simulating bioretention consist of lumped parameters and simplifications that do not fully account for fundamental hydrologic processes such as soil-water interactions. DRAINMOD has shown promise for obtaining detailed daily water balances within bioretention systems under continuous simulations. One significant advantage of DRAINMOD is that it uses the soil-water characteristic curve to account for fluctuations in soil moisture instead of assuming saturation; however, the model historically only produces daily outputs. For this study, DRAINMOD was modified to develop DRAINMOD-Urban, which allows high temporal resolution inputs and outputs, more closely matching the residence time of runoff in urban systems. DRAINMOD-Urban simulations of a bioretention cell in Ohio, USA, revealed that DRAINMOD-Urban could effectively produce hydrographs with a cumulative Nash-Sutcliffe Efficiency (NSE) of 0.60 for the 12 events that produced drainage over a 7-month monitoring period. Overflow was also modeled by DRAINMOD-Urban, but additional overflow data are necessary to derive conclusions about model effectiveness in predicting this hydrologic component. Input parameters previously calibrated for the DRAINMOD model did not translate well to DRAINMOD-Urban with the top-down approach applied in this study (NSE = 0.31 for drainage and NSE = −1.83 for overflow), but the bottom-up approach showed that parameters calibrated with DRAINMOD-Urban (NSE = 0.60 for drainage and NSE = −0.1 for overflow) could be used in DRAINMOD to obtain reasonable drainage volumes (25.6% error compared to measured values). This study suggests DRAINMOD-Urban is an effective tool for modeling bioretention hydrographs and demonstrates the importance of temporal scale in bioretention modeling by illustrating multiple model calibration approaches. Despite the promising results of this study, additional studies are recommended where validation of the model is performed at more sites, in particular for events with overflow. Further, sensitivity analysis of input parameters and comparison of DRAINMOD-Urban to other commonly used bioretention models would inform future modeling efforts.}, journal={JOURNAL OF HYDROLOGY}, author={Lisenbee, W. and Hathaway, Jon and Negm, L. and Youssef, M. and Winston, R.}, year={2020}, month={Mar} }
 @article{hathaway_tucker_spooner_hunt_2012, title={A Traditional Analysis of the First Flush Effect for Nutrients in Stormwater Runoff from Two Small Urban Catchments}, volume={223}, ISSN={["1573-2932"]}, DOI={10.1007/s11270-012-1327-x}, number={9}, journal={WATER AIR AND SOIL POLLUTION}, author={Hathaway, J. M. and Tucker, R. S. and Spooner, J. M. and Hunt, W. F.}, year={2012}, month={Nov}, pages={5903–5915} }
 @article{mccarthy_hathaway_hunt_deletic_2012, title={Intra-event variability of Escherichia coli and total suspended solids in urban stormwater runoff}, volume={46}, ISSN={["0043-1354"]}, DOI={10.1016/j.watres.2012.01.006}, abstractNote={Sediment levels are important for environmental health risk assessments of surface water bodies, while faecal pollution can introduce significant public health risks for users of these systems. Urban stormwater is one of the largest sources of contaminants to surface waters, yet the fate and transport of these contaminants (especially those microbiological) have received little attention in the literature. Stormwater runoff from five urbanized catchments were monitored for pathogen indicator bacteria and total suspended solids in two developed countries. Multiple discrete samples were collected during each storm event, allowing an analysis of intra-event characteristics such as initial concentration, peak concentration, maximum rate of change, and relative confidence interval. The data suggest that a catchment’s area influences pollutant characteristics, as larger catchments have more complex stormwater infrastructure and more variable pollutant sources. The variability of total suspended solids for many characteristics was similar to Escherichia coli, indicating that the variability of E. coli may not be substantially higher than that of other pollutants as initially speculated. Further, variations in E. coli appeared to be more commonly correlated to antecedent climate, while total suspended solids were more highly correlated to rainfall/runoff characteristics. This emphasizes the importance of climate on microbial persistence and die off in urban systems. Discrete intra-event concentrations of total suspended solids and, to a lesser extent E. coli, were correlated to flow, velocity, and rainfall intensity (adjusted by time of concentrations). Concentration changes were found to be best described by adjusted rainfall intensity, as shown by other researchers. This study has resulted in an increased understanding of the magnitude of intra-event variations of total suspended solids and E. coli and what physical and climatic parameters influence these variations.}, number={20}, journal={WATER RESEARCH}, author={McCarthy, D. T. and Hathaway, J. M. and Hunt, W. F. and Deletic, A.}, year={2012}, month={Dec}, pages={6661–6670} }
 @article{hathaway_moore_burkholder_hunt_2012, title={Temporal analysis of stormwater control measure effluent based on windows of harmful algal bloom (HAB) sensitivity: Are annual nutrient EMCs appropriate during HAB-sensitive seasons?}, volume={49}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2012.08.014}, DOI={10.1016/j.ecoleng.2012.08.014}, abstractNote={Nutrient removal by stormwater control measures (SCMs) is typically reported in terms of an average annual percent removal or effluent concentration. However, when the performance of these systems is considered in light of downstream receiving aquatic ecosystems, which display seasonal sensitivities to nutrient loadings, the use of an annual-based metric seems arbitrary. To investigate the potential temporal mismatch between nutrient-sensitive periods in receiving water bodies and average annual reporting periods adopted for SCM performance metrics, a case study is presented for four SCM types (constructed stormwater wetlands, bioretention, vegetated filter strips, and swales) draining to the Neuse River Estuary (NRE) in North Carolina, USA. Outbreaks of harmful algal blooms (HABs) in the NRE have been related to different nutrient forms at different times of the year, resulting in a "window" of importance for a given nutrient. These windows were utilized herein to define seasons of interest for various pollutants, and thus how SCM effluent data should be grouped to evaluate seasonal differences in performance. Effluent SCM nutrient concentrations were analyzed on an annual and HAB-sensitive seasonal basis. Although the use of annual performance metrics was deemed either appropriate or conservative for total phosphorus and nitrate–nitrite, effluent concentrations of total ammonia–nitrogen were significantly higher during HAB-sensitive seasons from both bioretention areas and stormwater wetlands. In the case of the NRE, these data suggest SCMs such as bioretention and stormwater wetlands may perform less effectively during periods of HAB sensitivity and that the contribution of SCMs to HAB control in sensitive water bodies may be overstated using presently accepted annual evaluation metrics. Though the seasonal analysis presented is specific to HAB formation in the Neuse River Estuary, evaluation of SCM effluent nutrient concentrations on the basis of nutrient-sensitive periods in receiving water bodies has broad application to evaluation of SCMs in any nutrient-sensitive watershed. The present study suggests that evaluation of SCM performance with respect to nutrient-sensitive periods in receiving aquatic ecosystems warrants further study.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Hathaway, Jon M. and Moore, Trisha L.C. and Burkholder, JoAnn M. and Hunt, William F.}, year={2012}, month={Dec}, pages={41–47} }
 @article{hathaway_hunt_graves_bass_caldwell_2011, title={Exploring fecal indicator bacteria in a constructed stormwater wetland}, volume={63}, ISSN={["1996-9732"]}, DOI={10.2166/wst.2011.539}, abstractNote={Microbial pollution in surface waters is a concern throughout the world, with both public health and economic implications. One contributing source to such pollution is stormwater runoff, often treated using various types of stormwater control measures. However, relatively little is known regarding microbe sequestration in constructed stormwater wetlands (CSWs), one type of commonly installed stormwater control measure. In this study, indicator bacteria concentrations in both the water and sediment of a CSW were evaluated at multiple locations. Results suggested that fecal coliform concentrations in stormwater runoff decrease through the system, with relatively consistent concentrations noted throughout the second half of the wetland. This potentially indicates a baseline concentration of fecal coliform is present due to internal processes such as animal activity and microbial persistence. However, wetland sediments showed little E. coli present during most sampling events, with minimal patterns existing with respect to sediment sampling location. CSW designs should promote optimization of hydraulic retention time and minimization of stormwater velocities to promote sedimentation and degradation of microbes by way of wetland treatment functions.}, number={11}, journal={WATER SCIENCE AND TECHNOLOGY}, author={Hathaway, J. M. and Hunt, W. F. and Graves, A. K. and Bass, K. L. and Caldwell, A.}, year={2011}, pages={2707–2712} }
 @article{hathaway_hunt_graves_wright_2011, title={Field Evaluation of Bioretention Indicator Bacteria Sequestration in Wilmington, North Carolina}, volume={137}, ISSN={["1943-7870"]}, DOI={10.1061/(asce)ee.1943-7870.0000444}, abstractNote={Although bioretention has been shown to remove or sequester a wide range of pollutants, relatively little study has been performed to evaluate its ability to sequester indicator bacteria. Two adjacent bioretention areas in Wilmington, North Carolina, were studied. The primary difference in the design of the two systems was soil depth. One bioretention cell was constructed with 25 cm of fill soil (Bioretention-S) and one with 60 cm of fill soil (Bioretention-D). The systems performed differently for indicator bacteria on the basis of multiple performance evaluation metrics. Bioretention-D showed concentration reductions of 70% and 89% for E. coli and enterococci, respectively. Effluent concentrations from Bioretention-D compared well to US EPA target values and other studies in literature. Conversely, Bioretention-S showed concentration “reductions” of -119% and -102% for E. coli and enterococci, respectively. Effluent concentrations from Bioretention-S were substantially higher than USEPA target values an...}, number={12}, journal={JOURNAL OF ENVIRONMENTAL ENGINEERING}, author={Hathaway, J. M. and Hunt, W. F. and Graves, A. K. and Wright, J. D.}, year={2011}, month={Dec}, pages={1103–1113} }
 @article{hathaway_hunt_2012, title={Indicator Bacteria Performance of Storm Water Control Measures in Wilmington, North Carolina}, volume={138}, ISSN={["1943-4774"]}, DOI={10.1061/(asce)ir.1943-4774.0000378}, abstractNote={Indicator bacteria are a common source of impairment in surface waters in the United States. Urban storm water runoff has been identified as a contributor to elevated indicator bacteria concentrations. Six storm water control measures (SCMs) were monitored in Wilmington, North Carolina, for E. coli and enterococci. Monitored SCMs included two storm water wet ponds, two bioretention cells, and two storm water wetlands. Sandier watersheds in Wilmington potentially lead to differences in SCM performance for indicator bacteria compared to SCMs implemented in clayey watersheds. Results showed E. coli and enterococci concentration reductions between 70 and 98% for the two wet ponds and a bioretention cell with a 60-cm-deep fill media. Other SCMs showed poor removal of indicator bacteria, in some cases negative, with storm water wetlands performing the poorest overall for the three SCM types. Further analysis showed that SCMs with high concentration reductions tended to have geometric mean effluent concentration...}, number={2}, journal={JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING}, author={Hathaway, J. M. and Hunt, W. F.}, year={2012}, month={Feb}, pages={185–197} }
 @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{hathaway_hunt_2011, title={Evaluation of First Flush for Indicator Bacteria and Total Suspended Solids in Urban Stormwater Runoff}, volume={217}, ISSN={["1573-2932"]}, DOI={10.1007/s11270-010-0574-y}, number={1-4}, journal={WATER AIR AND SOIL POLLUTION}, author={Hathaway, Jon M. and Hunt, William F.}, year={2011}, month={May}, pages={135–147} }
 @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} }
 @article{hathaway_cook_evans_2010, title={Nutrient removal capability of a constructed wetland receiving groundwater contaminated by swine lagoon seepage}, volume={53}, DOI={10.13031/2013.30079}, abstractNote={Seepage from waste lagoons has the potential to leach into underlying groundwater systems. Groundwater flow can transport this nutrient-rich lagoon seepage to surrounding surface waters where water quality degradation may occur. Groundwater contaminated by lagoon seepage can be removed from the shallow aquifer by pumping, but the pumped water must still be treated before discharge into surface waters. Constructed wetlands have been successfully implemented to attenuate nitrogen and phosphorus in wastewaters. A constructed wetland receiving groundwater contaminated by swine lagoon seepage was monitored for four years during this study. Wetland effluent concentrations were variable but were on average substantially lower than influent concentrations. During the four-year study, the wetland assimilated between 76% and 84% of the influent total nitrogen and between 22% and 42% of the influent total phosphorus, or 520 to 575 kg of total nitrogen per hectare per year and 83 to 158 kg of total phosphorus per hectare per year. Residence time likely played a major role in nutrient assimilation within the wetland.}, number={3}, journal={Transactions of the ASABE}, author={Hathaway, J. M. and Cook, M. J. and Evans, R. O.}, year={2010}, pages={741–749} }
 @article{hathaway_hunt_simmons_2010, title={Statistical Evaluation of Factors Affecting Indicator Bacteria in Urban Storm-Water Runoff}, volume={136}, ISSN={0733-9372 1943-7870}, url={http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0000278}, DOI={10.1061/(asce)ee.1943-7870.0000278}, abstractNote={An urban watershed in Raleigh, North Carolina, was monitored for indicator bacteria during 20 rain events. Results showed elevated levels of E. coli, enterococci, and fecal coliform. Samples were compared based on seasonality and were found to be statistically different ( p<0.05 ) , with pairwise comparisons indicating significantly lower concentrations of E. coli and fecal coliform during the winter ( p<0.05 ) . Enterococci concentrations were substantially lower in the winter and fall, but no significant differences were found between seasons during pairwise comparisons ( p<0.05 ) . Correlation analyses showed multiple significant relationships between antecedent climate parameters, flow characteristics, and indicator bacteria concentrations. More detailed multiple linear regression yielded explanatory variables related to antecedent climate conditions. Variables were generally related to temperature and moisture conditions in the atmosphere and soil. The results of this study show indicator bacteria co...}, number={12}, journal={Journal of Environmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={Hathaway, J. M. and Hunt, W. F. and Simmons, O. D., III}, year={2010}, month={Dec}, pages={1360–1368} }
 @article{hathaway_hunt_2010, title={Evaluation of Storm-Water Wetlands in Series in Piedmont North Carolina}, volume={136}, ISSN={["1943-7870"]}, DOI={10.1061/(asce)ee.1943-7870.0000130}, abstractNote={Three storm-water wetlands in series were monitored in a heavily urbanized 12.5 ha watershed in Mooresville, North Carolina. Monitoring of this system allowed an examination of the diminishing returns provided by three successive best management practices (BMPs) of a similar type. At least 80% of the total concentration reduction for all pollutants occurred within the first wetland cell. Only the first wetland cell significantly ( p<0.05 ) reduced all pollutants tested. No pollutant was significantly reduced from the outlet of Wetland Cell 2 to the outlet of Wetland Cell 3 ( p<0.05 ) . Median complete system (outlet of Wetland Cell 3) effluent concentrations for total suspended solids, total phosphorus, total nitrogen, and turbidity were 8, 0.09, 0.73 mg/L, and 10 NTU, respectively, which compared favorably to published results. Organic nitrogen generated from wetland vegetation seemed to result in a background source of nitrogen in the wetlands, supporting the idea of an irreducible concentration for nit...}, number={1}, journal={JOURNAL OF ENVIRONMENTAL ENGINEERING}, author={Hathaway, J. M. and Hunt, W. F.}, year={2010}, month={Jan}, pages={140–146} }
 @article{hathaway_hunt_jadlocki_2009, title={Indicator Bacteria Removal in Storm-Water Best Management Practices in Charlotte, North Carolina}, volume={135}, ISSN={["0733-9372"]}, DOI={10.1061/(asce)ee.1943-7870.0000107}, abstractNote={Water quality degradation due to pathogen pollution is a major concern in the United States. Storm-water runoff is an important contributor to the transport of indicator bacteria from urbanized watersheds to nearby surface waters. With total maximum daily loads being established to reduce the export of indicator bacteria to surface waters, storm-water best management practices (BMPs) may be an important tool in treating indicator bacteria in runoff. However, the ability of these systems to remove indicator bacteria is not well established. A study in Charlotte, N.C., monitored nine storm-water BMPs (one wet pond, two storm-water wetlands, two dry detention basins, one bioretention area, and three proprietary devices) for fecal coliform and Escherichia coli (E. coli). A wet pond, two wetlands, a bioretention area, and a proprietary device all removed fecal coliform with an efficiency higher than 50%; however, only the wetlands and bioretention area had significantly different influent and effluent concentr...}, number={12}, journal={JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE}, author={Hathaway, J. M. and Hunt, W. F. and Jadlocki, S.}, year={2009}, month={Dec}, pages={1275–1285} }
 @article{hunt_hathaway_winston_jadlocki_2010, title={Runoff Volume Reduction by a Level Spreader-Vegetated Filter Strip System in Suburban Charlotte, NC}, volume={15}, ISSN={["1943-5584"]}, DOI={10.1061/(asce)he.1943-5584.0000160}, abstractNote={The premise of low impact development (LID) is to reduce runoff volumes while simultaneously matching target (often predevelopment) infiltration and evapotranspiration volumes. Many structural practices used in LID, such as bioretention, infiltration trenches, and permeable pavement, require a seasonally high water table (SHWT) to be 1–2 m from the surface. Conversely, level spreader–vegetated filter strip systems can be implemented in locations where a SHWT would restrict the use of other practices. A 19.4 m long reinforced concrete level spreader upslope of a 900  m2 mixed grass/weed vegetated filter strip was monitored for runoff reduction for 23 precipitation events from November 2005 to January 2007 in Charlotte, N.C. The practice treated runoff from a 0.87 ha (2.15 acre) residential watershed. Of the 23 monitored events, only 3 produced outflow. All events which produced outflow exceeded 40 mm (1.6 in.) of precipitation. Cumulative volume reduction associated with the events was 85%, which compares ...}, number={6}, journal={JOURNAL OF HYDROLOGIC ENGINEERING}, author={Hunt, W. F. and Hathaway, J. M. and Winston, R. J. and Jadlocki, S. J.}, year={2010}, month={Jun}, pages={499–503} }
 @article{collins_hunt_hathaway_2010, title={Side-by-Side Comparison of Nitrogen Species Removal for Four Types of Permeable Pavement and Standard Asphalt in Eastern North Carolina}, volume={15}, ISSN={["1943-5584"]}, DOI={10.1061/(asce)he.1943-5584.0000139}, abstractNote={A 1 year-old parking lot in eastern North Carolina consisting of four types of side-by-side permeable pavement and standard asphalt was monitored from January 2007 to July 2007 for water quality differences among pavement types. The four permeable sections were pervious concrete (PC), two different types of permeable interlocking concrete pavement (PICP) with small-sized aggregate in the joints and having 12.9% (PICP1) and 8.5% (PICP2) open surface area, and concrete grid pavers (CGP) filled with sand. The site was located in poorly drained soils, and all permeable sections were underlain by a crushed stone base with a perforated pipe underdrain. Composite, flow-weighted samples of atmospheric deposition and asphalt runoff were compared to those of permeable pavement subsurface drainage for pH, TN, NO2,3 –N , TKN, NH4 –N , and ON concentrations and loads. All pavements buffered acidic rainfall pH ( p<0.01 ) . The pH of permeable pavement subsurface drainage was higher than that of asphalt runoff ( p<0.01 ...}, number={6}, journal={JOURNAL OF HYDROLOGIC ENGINEERING}, author={Collins, Kelly A. and Hunt, William F. and Hathaway, Jon M.}, year={2010}, month={Jun}, pages={512–521} }
 @article{hathaway_hunt_2008, title={Field evaluation of level spreaders in the Piedmont of North Carolina}, volume={134}, DOI={10.1061/(ASCE)0733-9437(2008)134:4(538)}, abstractNote={Level spreaders are commonly used in combination with riparian buffers as a stormwater best management practice in many parts of the United States. These systems have not been extensively studied in urbanized environments to determine if they can provide a long-term water quality benefit. In winter 2005, 24 level spreaders were evaluated in the Piedmont of North Carolina. Detailed observations were made at 20 of these locations. The results of the study indicate that level spreaders may not be the versatile structure they are perceived to be. No level spreader-riparian buffer system was able to provide diffuse flow through the riparian buffer from the level spreader to the stream. Common causes for failure to maintain diffuse flow included: lack of maintenance (12 cases), poor design (11), riparian topography/content (11), level spreader lip not level (seven), built with easily eroded materials (six), poor construction methods (three), and human interference (two). This field evaluation indicates that lev...}, number={4}, journal={Journal of Irrigation and Drainage Engineering}, author={Hathaway, J. M. and Hunt, W. F.}, year={2008}, pages={538–542} }
 @article{collins_hunt_hathaway_2008, title={Hydrologic comparison of four types of permeable pavement and standard asphalt in eastern North Carolina}, volume={13}, DOI={10.1061/(ASCE)1084-0699(2008)13:12(1146)}, abstractNote={A permeable pavement parking lot in eastern North Carolina consisting of four types of permeable pavement and standard asphalt was monitored from June 2006 to July 2007 for hydrologic differences in pavement surface runoff volumes, total outflow volumes, peak flow rates, and time to peak. The four permeable sections were pervious concrete (PC), two types of permeable interlocking concrete pavement (PICP) with small-sized aggregate in the joints and having 12.9% (PICP1) and 8.5% (PICP2) open surface area, and concrete grid pavers (CGP) filled with sand. The site was located in poorly drained soils, and all permeable sections were underlain by a crushed stone base layer with a perforated underdrain. All permeable pavements significantly reduced surface runoff volumes and peak flow rates from those of asphalt (p<0.01) . Of the permeable pavements, CGP generated the greatest surface runoff volumes (p<0.01) . The PICP1 and CGP cells generated significantly lower total outflow volumes than all other sections ev...}, number={12}, journal={Journal of Hydrologic Engineering}, author={Collins, K. A. and Hunt, W. F. and Hathaway, J. M.}, year={2008}, pages={1146–1157} }
 @article{hunt_smith_jadlocki_hathaway_eubanks_2008, title={Pollutant removal and peak flow mitigation by a bioretention cell in urban Charlotte, NC}, volume={134}, DOI={10.1061/(asce)0733-9372(2008)134:5(403)}, abstractNote={Bioretention is a stormwater treatment practice that has gained popularity due to its aesthetics, potential to reduce flooding, and early documented improvements to stormwater quality. A bioretention cell in an urban setting was examined in Charlotte, N.C. from 2004 to 2006. Flow-weighted, composite water quality samples were collected for 23 events and analyzed for TKN, N H4 -N , N O2-3 -N , TP, TSS, BOD-5, Cu, Zn, Fe, and Pb. Grab samples were collected from 19 storms for fecal coliform and 14 events for Escherichia coli (E. coli). There were significant reductions (p<0.05) in the concentrations of TN, TKN, N H4 -N , BOD-5, fecal coliform, E. Coli, TSS, Cu, Zn, and Pb. Iron concentrations significantly increased (p<0.05) . N O2-3 -N concentrations were essentially unchanged. Efficiency ratios for TN, TKN, N H4 -N , TP, and TSS were 0.32, 0.44, 0.73, 0.31, and 0.60, respectively. Fecal coliform and E. coli efficiency ratios were 0.69 and 0.71, respectively. Efficiency ratios for Zn, Cu, and Pb were 0.77,...}, number={5}, journal={Journal of Environmental Engineering (New York, N.Y.)}, author={Hunt, W. F. and Smith, J. T. and Jadlocki, S. J. and Hathaway, J. M. and Eubanks, P. R.}, year={2008}, pages={403–408} }
 @article{cook_hathaway_evans_2008, title={The impact of swine lagoon seepage on shallow groundwater quality: Groundwater remediation through lagoon closure and pumping}, volume={51}, DOI={10.13031/2013.24528}, abstractNote={Anaerobic lagoons have been used extensively since about 1960 to temporarily store and partially treat livestock waste from concentrated animal production facilities. An earlier study characterized an unlined swine lagoon located in the Middle Coastal Plain of North Carolina and detected elevated mineral nitrogen concentrations (nitrogen as both nitrate and total ammoniacal nitrogen) 38 m down gradient from the lagoon. As this site was shown to be a potential source of nonpoint-source pollution, further study was needed to characterize the aerial extent of the seepage plume and remediate the contaminated groundwater. Hydrologic and water quality monitoring of the site was conducted from March 1999 to September 2004, a period during which the lagoon went from being semiactive to completely closed out. Analysis of data collected prior to lagoon closure indicated that seepage from the lagoon traveled to a nearby channelized stream. Total ammoniacal nitrogen (TAN = NH3-N + NH4-N) concentrations from monitoring wells installed between the lagoon and the channelized stream averaged 121 mg L-1 of TAN, with the highest concentrations exceeding 170 mg L-1. TAN concentrations in the stream 150 m down gradient from the lagoon ranged from 10 to 25 mg L-1. Monitoring of groundwater levels and subsurface water quality continued following the closure of the lagoon in March 2001, as well as through the installation of a groundwater pumping system and construction of a wetland that received and treated the contaminated groundwater. The average hydraulic gradient decreased from 0.0033 m m-1, prior to the activation of a groundwater pumping system (Mar. 1999 to Jan. 2000) to 0.0010 m m-1 after pumping was initiated (Sept. 2000 to Sept. 2004). Although the direction of groundwater flow was unaffected by the addition of the pumping system and water control structure, the average hydraulic gradient was reduced by 70%. Since the installation of the pumping system, approximately 17,900 m3 of subsurface water has been pumped, removing 1200 kg of TN from the groundwater plume. TAN concentrations steadily declined from 120 mg L-1 at the onset of pumping in September 2000 to less than 6 mg L-1 by September 2004.}, number={3}, journal={Transactions of the ASABE}, author={Cook, M. J. and Hathaway, J. M. and Evans, R. O.}, year={2008}, pages={891–900} }