TY - JOUR TI - Economic Analysis of Alternative Effluent Treatment Options for Pond Production of Hybrid Striped Bass in Aurora, North Carolina AU - Sydorovych, Olha AU - Daniels, Harry T2 - Aquaculture Economics & Management AB - The focus of this article is the post-harvest treatment of effluent from hybrid striped bass (HSB) pond aquaculture to meet effluent discharge standards for Biochemical Oxygen Demand (BOD; 5 mg/L) and chlorophyll-α (40 μg/L) established by the North Carolina Division of Water Quality (DWQ). The specific application is to HSB pond aquaculture in Aurora, North Carolina. A variety of effluent treatment options were proposed and evaluated based on their efficacy in reaching the new standards on a 28.8-ha (72-acre) HSB farm. The economic feasibility of the proposed options ranged from positive $499 to negative $121,691 using the partial budget methodology. Our results indicate that retaining water on-farm for subsequent production cycles instead of discharging had the highest positive impact ($499) on annual farm budgets and may reduce production costs without compromising fish yields. Application of effluents onto existing or newly planted trees was also an attractive alternative because of the possible generation of additional income and the conversion of a point source discharge into a non-point discharge. By conversion of a point source into a non-point source the pond effluents would also benefit from the additional biological treatment and filtration of the effluents by the trees and the associated soil organisms. DA - 2011/2/28/ PY - 2011/2/28/ DO - 10.1080/13657305.2011.549163 VL - 15 IS - 1 SP - 46–70 SN - 1365-7305 1551-8663 UR - http://dx.doi.org/10.1080/13657305.2011.549163 ER - TY - JOUR TI - A comparative study on the effectiveness of chlorine dioxide gas, ozone gas and e-beam irradiation treatments for inactivation of pathogens inoculated onto tomato, cantaloupe and lettuce seeds AU - Trinetta, V. AU - Vaidya, N. AU - Linton, R. AU - Morgan, M. T2 - International Journal of Food Microbiology AB - The increase in reported food-borne outbreaks linked with consumption of raw fruits and vegetables has motivated new research focusing on prevention of pre-harvest produce contamination. This study evaluates and compares the effectiveness of three non-thermal technologies, chlorine dioxide gas, ozone gas and e-beam irradiation, for inactivation of Salmonella enterica and Escherichia coli O157:H7 on pre-inoculated tomato, lettuce and cantaloupe seeds, and also their corresponding effect on seeds germination percentage after treatments. Samples were treated with 10 mg/l ClO2 gas for 3 min at 75% relative humidity, with 4.3 mg/l ozone gas for 5 min and with a dose of 7 kGy electron beam for 1 min. Initial load of pathogenic bacteria on seeds was ~ 6 log CFU/g. Results demonstrate that all treatments significantly reduce the initial load of pathogenic bacteria on seeds (p < 0.05). In particular, after ozone gas treatments 4 log CFU/g reduction was always observed, despite the seeds and/or microorganisms treated. ClO2 and e-beam treatments were noticeably more effective against Salmonella on contaminated tomato seeds, where 5.3 and 4.4 log CFU/g reduction were respectively observed. Germination percentage was not affected, except for cantaloupe seeds, where the ratio was significantly lowered after ClO2 treatments. Overall, the results obtained show the great applicability of these non-thermal inactivation techniques to control and reduce pathogenic bacteria contamination of seeds. DA - 2011/3// PY - 2011/3// DO - 10.1016/j.ijfoodmicro.2011.02.014 VL - 146 IS - 2 SP - 203-206 J2 - International Journal of Food Microbiology LA - en OP - SN - 0168-1605 UR - http://dx.doi.org/10.1016/j.ijfoodmicro.2011.02.014 DB - Crossref ER - TY - JOUR TI - Enhancing the transition to kindergarten: A randomized trial to test the efficacy of the “Stars” summer kindergarten orientation program AU - Berlin, Lisa J. AU - Dunning, Rebecca D. AU - Dodge, Kenneth A. T2 - Early Childhood Research Quarterly AB - This randomized trial tested the efficacy of an intensive, four-week summer program designed to enhance low-income children's transition to kindergarten (n's = 60 program children, 40 controls). Administered in four public schools, the program focused on social competence, pre-literacy and pre-numeracy skills, school routines, and parental involvement. Hierarchical linear modeling indicated that the program significantly improved teachers' ratings of (a) the transition to the social aspect of kindergarten for girls (but not boys); and (b) the transition to kindergarten routines for the subgroup of children who had the same teacher for kindergarten as for the summer program. Findings are discussed in terms of practices and policies for supporting children's transition to school. DA - 2011/4// PY - 2011/4// DO - 10.1016/j.ecresq.2010.07.004 VL - 26 IS - 2 SP - 247-254 J2 - Early Childhood Research Quarterly LA - en OP - SN - 0885-2006 UR - http://dx.doi.org/10.1016/j.ecresq.2010.07.004 DB - Crossref KW - Kindergarten transition KW - Preschool education KW - Sex differences ER - TY - JOUR TI - Eye development in the box jellyfish Carybdea marsupialis AU - Valley, Jenna AU - Martin, Vicki T2 - Developmental Biology AB - Cnidarians are the most primitive invertebrates alive today to possess eyes. The complex eyes of the cubozoan jellyfish Carybdea marsupialis exhibit many similarities to the camera-type eyes of higher metazoans including the presence of a cornea, lens, and retina of ciliated photoreceptors. It is these similarities that make understanding the evolution and development of eyes in basal cnidarians important, as they may lead to a better understanding of eye evolution. During the transformation of the polyp to the eye-bearing medusa, the development and arrangement of several components were followed including the neuropeptide FMRFamide, UV opsin-like protein (indicates photoreceptor formation), J1-crystallin (indicates lens formation), and shielding pigment formation. The first ocelli to appear were the complex eyes followed by the simple ocelli; the small complex eye was the first to exhibit pigment formation (melanin) as well as photoreceptor maturation. J1-crystallin was located in the developing lenses/lens-like material in the complex eyes and slit ocelli. Extensive neurological rearrangement and development takes place during the transformation. Developmental mechanisms in eye formation similar to both vertebrates and invertebrates were seen. This study clearly demonstrates the presence of the basic optic molecules and developmental mechanisms in the first multicellular animals possessing complex camera-type eyes. DA - 2011/8// PY - 2011/8// DO - 10.1016/j.ydbio.2011.05.594 VL - 356 IS - 1 SP - 160-161 J2 - Developmental Biology LA - en OP - SN - 0012-1606 UR - http://dx.doi.org/10.1016/j.ydbio.2011.05.594 DB - Crossref ER - TY - CONF TI - Streambank erosion and instability induced by groundwater seepage AU - Midgley, T.L. AU - Fox, G.A. AU - Wilson, G.V. AU - Heeren, D.M. AU - Simon, A. AU - Langendoen, E.J. C2 - 2011/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2011, ASABE 2011 DA - 2011/// VL - 4 SP - 3009-3029 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-81255185841&partnerID=MN8TOARS ER - TY - JOUR TI - Streambank Erosion and Instability Induced by Groundwater Seepage AU - Midgley, Taber Leon AU - Fox, Garey A AU - Wilson, Glenn V AU - Heeren, Derek M AU - Simon, Andrew AU - Langendoen, Eddy J T2 - 2011 Louisville, Kentucky, August 7 - August 10, 2011 AB - Excessive sediment is one of the most common surface water pollutants. It diminishes water quality and destroys aquatic habitat. Streambank erosion is known to be a major source of sediment in streams and rivers, contributing as much as 80% of the total sediment load in some watersheds. Little work has been done to study the effects of seepage on streambank erosion and failure. Prior research, primarily in the laboratory under well-defined and controlled conditions, has examined seepage as a mechanism for bank erosion, but more needs to be done to validate conclusions derived from the laboratory with field data. This project studied a streambank on Dry Creek (a tributary to Little Topashaw Creek) located in Chickasaw County, Mississippi. The bank was previously observed to produce seepage even during dry summer months. This creek is a deeply incised stream in the Yalobusha Watershed with near 90 degree banks. The creek flows through alluvial plains under cultivation and surrounded by forested areas. Excess sediment has been identified as the main water quality issue in the watershed with gullies and banks being the main sources. Watershed geology is characterized by silt loam and clay loam with a more conductive loamy sand between the loam and an underlying cohesive layer. The site was initially instrumented with a network of tensiometers and observation wells. Groundwater conditions and bank erosion were monitored for several weeks, followed by an induced seepage experiment. A trench installed 2.8 m from the edge of the bank and approximately 2 m below ground surface was used to provide a constant head for groundwater flow in the near-bank area. The bank face was outfitted with a seepage collection device that measured seepage flow rate and sediment transport. Groundwater conditions were again monitored by the tensiometer and observation well network. Experiments consisted of a trench injection at a constant head and observations of flow rates, erosion rates, soil-water pressures, and water table elevations. Flow rates varied from 0.004 L/min to 1.16 L/min at different locations on the bank. It was observed that the seeps experienced self-healing erosion in which upper layer cohesive soil failures blocked further particle mobilization. One experiment simulated fluvial erosion removing the failed material, thereby, resulting in combined erosion rates of over 6000 g/min. Seepage erosion could be a dominate mechanism of streambank failure where the self-healing process is not occurring. DA - 2011/// PY - 2011/// DO - 10.13031/2013.37385 ER - TY - CONF TI - Measuring erodibility of cohesive soils using laboratory jet erosion tests AU - Al-Madhhachi, A.T. AU - Hanson, G.J. AU - Fox, G.A. AU - Tyagi, A.K. AU - Bulut, R. AB - Many factors affect the erodibility of cohesive soils, such as the soil characteristics, soil moisture content, and properties of the eroding fluid. Typically the erosion rate of cohesive soils is quantified using an excess shear stress equation, dependent on two major soil parameters: the critical shear stress (τc) and the erodibility coefficient (kd). A submerged jet test (JET — Jet Erosion Test) is one method for measuring these parameters. In this study, a laboratory JET and a new miniature version of the device ("mini" JET), with the advantage of being easier to use in the field, were used to measure τc and kd for various soils. The objective of this study was to determine if the "mini" JET estimated equivalent values for τc and kd. Two different soils types (silty sand and clayey sand) were used in comparing the performance of the two devices. Sieve analysis, hydrometer, and plasticity index tests were also performed to characterize these two soils. Test samples of the soils were prepared at three to seven different water contents with equivalent compaction effort (25 blows per layer). In-order to compare the performance and repeatability of both JET devices, tests were performed on paired samples prepared in the same way and tested at the same time. Reasonably equivalent measured kd were obtained with the two JET devices for both soils. Results indicated some variability in measuring τc and kd due to variability in the subsamples of the cohesive soil and differences in soil moisture levels. These results also indicated that settling back of some of the eroded soil into the scour area of the new "mini" JET device may have caused differences in measured τc relative to the original JET device. Even though there was an observed difference in the observed τc, the differences were consistent. The relationships between measured τc and kd obtained from both JET devices also compared reasonably well with those observed in previous field research. C2 - 2011/// C3 - World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress DA - 2011/// DO - 10.1061/41173(414)244 SP - 2350-2359 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79960437161&partnerID=MN8TOARS ER - TY - JOUR TI - Flow and transport experiments for a streambank seep originating from a preferential flow pathway AU - Fox, G.A. AU - Heeren, D.M. AU - Miller, R.B. AU - Mittelstet, A.R. AU - Storm, D.E. T2 - Journal of Hydrology AB - Streambank seeps commonly originate from localized heterogeneity or preferential flow pathways (PFPs) in riparian floodplains. However, limited field data have been reported on ground water seep flows and solute transport to seeps from PFPs. The objective of this research was to build upon previous floodplain-scale investigations of PFPs by analyzing seep discharge and transport characteristics through a single PFP. An important research question was whether this PFP could be conceptualized as a homogeneous, one-dimensional flow path. Streambank seep discharge measurements were obtained by inducing a hydraulic head in a trench injection system. Also, co-injection of Rhodamine WT (RhWT) and a potassium chloride (KCl) tracer over a 60-min period was used to investigate transport dynamics. Seep discharge and breakthrough curves for electrical conductivity (EC) and RhWT were measured at the streambank using a lateral flow collection device. The breakthrough curves were fit to one-dimensional convective-dispersion equations (CDEs) to inversely estimate solute transport parameters. The PFP from which the seep originated was clean, coarse gravel (6% by mass less than 2.0 mm) surrounded by gravel with finer particles (20% by mass less than 2.0 mm). Located approximately 2 m from the trench, the seep (50 cm by 10 cm area) required at least 40 cm of hydraulic head for flow to emerge at the streambank. At a higher hydraulic head of 125 cm, seep discharge peaked at 3.5 L/min. This research verified that localized PFPs can result in the rapid transport of water (hydraulic conductivity on the order of 400 m/d) and solutes once reaching a sufficient near-bank hydraulic head. A one-dimensional equilibrium CDE was capable of simulating the EC (R2 = 0.94) and RhWT (R2 = 0.91) breakthrough curves with minimal RhWT sorption (distribution coefficient, Kd, equal to 0.1 cm3/g). Therefore, the PFP could be conceptualized as a one-dimensional, homogenous flow and transport pathway. These results are consistent with previous research observing larger-scale phosphorus transport. DA - 2011/// PY - 2011/// DO - 10.1016/j.jhydrol.2011.04.014 VL - 403 IS - 3-4 SP - 360-366 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79956341660&partnerID=MN8TOARS KW - Contaminant transport KW - Preferential flow KW - Rhodamine WT KW - Riparian floodplain KW - Seepage ER - TY - JOUR TI - Escherichia coli Load Reduction from Runoff by Vegetative Filter Strips: A Laboratory-Scale Study AU - Fox, Garey A. AU - Matlock, Emily M. AU - Guzman, Jorge A. AU - Sahoo, Debabrata AU - Stunkel, Kevin B. T2 - Journal of Environmental Quality AB - Vegetative filter strips (VFS) are commonly used best management practices for removing contaminants from runoff. Additional research is warranted to determine their efficiency and the most appropriate metrics for predicting fecal bacteria reductions. The objective of this research was to determine VFS effectiveness in removing from runoff relative to inflow rate, infiltration capacity, and flow concentration. This research also investigated the presence of in runoff from clean water runon after diluted manure runon events. A laboratory-scale VFS soil box (200 cm long, 100 cm wide, 7.5% slope) was packed with a sandy loam soil. Ten constant-flow VFS experiments were conducted with and without vegetation (8-10 cm ryegrass [ L.]) at low (20-40 cm s), medium (40-60 cm s), and high (85-120 cm s) flow rates and for a full (100 cm) or concentrated (40 cm) VFS flow width to simulate a channelizing flow condition. Two runon events were investigated for each experimental condition: (i) diluted liquid swine manure runon and (ii) clean water runon 48 h afterward. was used as an indicator of fecal contamination and was quantified by the most probable number (MPN) technique. No concentration reductions were observed based on peak outflow concentrations, and only small concentration reductions were observed based on outflow event mean concentrations. The mass reductions ranged from 22 to 71% and were strongly correlated to infiltration or runoff reduction ( = 0.88), which was dependent on the degree of flow concentration. Little to no effect of sedimentation on transport was observed, hypothesized to be due to minimum attachment to sediment particles because the bacteria originated from manure sources. Therefore, the design of VFS for bacteria removal should be based on the infiltration capacity in the VFS and should prevent concentrated flow, which limits total infiltration. The event mean concentrations in clean water runon experiments were between 10 and 100 MPN per 100 mL; therefore, under these conditions, VFS served as a source of residual from previous runon events. DA - 2011/5// PY - 2011/5// DO - 10.2134/jeq2010.0391 VL - 40 IS - 3 SP - 980-988 J2 - J. Environ. Qual. LA - en OP - SN - 0047-2425 UR - http://dx.doi.org/10.2134/jeq2010.0391 DB - Crossref ER - TY - JOUR TI - Stage-dependent transient storage of phosphorus in alluvial floodplains AU - Heeren, D.M. AU - Fox, G.A. AU - Miller, R.B. AU - Storm, D.E. AU - Fox, A.K. AU - Penn, C.J. AU - Halihan, T. AU - Mittelstet, A.R. T2 - Hydrological Processes AB - Abstract Models for contaminant transport in streams commonly idealize transient storage as a well mixed but immobile system. These transient storage models capture rapid (near‐stream) hyporheic storage and transport, but do not account for large‐scale, stage‐dependent interaction with the alluvial aquifer. The objective of this research was to document transient storage of phosphorus (P) in coarse gravel alluvium potentially influenced by large‐scale, stage‐dependent preferential flow pathways (PFPs). Long‐term monitoring was performed at floodplain sites adjacent to the Barren Fork Creek and Honey Creek in northeastern Oklahoma. Based on results from subsurface electrical resistivity mapping which was correlated to hydraulic conductivity data, observation wells were installed both in higher hydraulic conductivity and lower hydraulic conductivity subsoils. Water levels in the wells were monitored over time, and water samples were obtained from the observation wells and the stream to document P concentrations at multiple times during high flow events. Contour plots indicating direction of flow were developed using water table elevation data. Contour plots of total P concentrations showed the alluvial aquifer acting as a transient storage zone, with P‐laden stream water heterogeneously entering the aquifer during the passage of a storm pulse, and subsequently re‐entering the stream during baseflow conditions. Some groundwater in the alluvial floodplains had total P concentrations that mirrored the streams' total P concentrations. A detailed analysis of P forms indicated that particulate P (i.e. P attached to particulates greater than 0·45 µm) was a significant portion of the P transport. This research suggests the need for more controlled studies on stage‐dependent transient storage in alluvial systems. Copyright © 2011 John Wiley & Sons, Ltd. DA - 2011/// PY - 2011/// DO - 10.1002/hyp.8054 VL - 25 IS - 20 SP - 3230-3243 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-80052952199&partnerID=MN8TOARS KW - alluvial floodplains KW - phosphorus KW - preferential flow KW - subsurface transport KW - transient storage ER - TY - JOUR TI - Option-specific student outcomes to meet biological engineering program criteria AU - Fox, G.A. AU - Elliott, R.L. AU - Bellmer, D. T2 - Applied Engineering in Agriculture DA - 2011/// PY - 2011/// VL - 27 IS - 5 SP - 857-860 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-80053937677&partnerID=MN8TOARS ER - TY - CONF TI - Evaluation of the Bank Stability and Toe Erosion Model (BSTEM) for predicting lateral streambank retreat on ozark streams AU - Midgley, T.L. AU - Fox, G.A. AU - Heeren, D.M. AB - Streambank erosion is known to be a major source of sediment in streams and rivers. The Bank Stability and Toe Erosion Model (BSTEM) was developed by the USDA-ARS National Sedimentation Laboratory in order to predict streambank retreat due to both fluvial erosion and geotechnical failure. Few model evaluations for bank retreat have been performed to date. The objective of this research was to evaluate BSTEM's ability to predict bank retreat on Ozark ecoregion streams, assess the importance of accurate geotechnical and fluvial erosion soil parameter values, and evaluate the importance of the near bank water table elevation on bank stability. The model was applied to a streambank on the Barren Fork Creek in northeastern Oklahoma. This site experienced significant bank retreat (between 7.8 and 20.9 m over a 100-m length of stream) between April and October 2009 based on regular surveys of the bank profile. BSTEM (version 5.2) was not originally programmed to run multiple hydrographs iteratively, so an additional subroutine was written which automatically input the stream stage. The new subroutine was also written to lag the water table response in the near-bank ground water depending on user settings. Eight BSTEM simulations were performed using combinations of the following input data: with and without a water table lag; default BSTEM geotechnical parameters (moderate silt loam) versus laboratory measured geotechnical parameters for the silt loam layer based on direct shear tests on saturated soil samples; and default BSTEM fluvial erosion parameters versus field measured fluvial erosion parameters from submerged jet tests on the silt loam layer. Using default BSTEM input values underestimated the actual erosion that occurred. Lagging the water table predicted more geotechnical failures resulting in greater bank retreat. Using measured fluvial and geotechnical parameters and a water table lag also under predicted bank retreat (approximately 4.0 m), but did predict the appropriate timing of bank collapses. C2 - 2011/// C3 - World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress DA - 2011/// DO - 10.1061/41173(414)209 SP - 1991-2000 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79960424136&partnerID=MN8TOARS ER - TY - JOUR TI - Evaluation of a stream-aquifer analysis test for deriving reach-scale streambed conductance AU - Fox, G.A. AU - Heeren, D.M. AU - Kizer, M.A. T2 - Transactions of the ASABE DA - 2011/// PY - 2011/// VL - 54 IS - 2 SP - 473-479 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79954527847&partnerID=MN8TOARS ER - TY - CONF TI - Measuring the erodibility of cohesive soils influenced by seepage forces using a laboratory jet erosion test device AU - Al-Madhhachi, A.-S.T. AU - Fox, G.A. AU - Tyagi, A.K. AU - Hanson, G.J. AU - Bulut, R. C2 - 2011/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2011, ASABE 2011 DA - 2011/// VL - 4 SP - 3030-3041 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-81255171946&partnerID=MN8TOARS ER - TY - CONF TI - Groundwater seepage mechanisms of streambank erosion and failure AU - Fox, G.A. AU - Wilson, G.V. AU - Midgley, T. AU - Almadhhachi, A. AU - Carson, R. C2 - 2011/// C3 - ASABE - International Symposium on Erosion and Landscape Evolution 2011 DA - 2011/// SP - 25-33 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84861644621&partnerID=MN8TOARS ER - TY - JOUR TI - Groundwater Seepage Mechanisms of Streambank Erosion and Failure AU - Fox, Garey A AU - Wilson, Glenn V AU - Midgley, Taber AU - Almadhhachi, Abdulsahib AU - Carson, Rachel T2 - International Symposium on Erosion and Landscape Evolution (ISELE), 18-21 September 2011, Anchorage, Alaska AB - The importance of groundwater seepage and pipeflow is unknown with respect to other fundamental processes of streambank erosion and failure, although seepage and pipeflow features are observed on streambanks throughout the world that span a range of geomorphologic conditions. Previous field and laboratory research on seepage erosion has demonstrated that groundwater seepage and pipeflow play an important role in the erosion and failure of streambanks. This previous research pointed to seepage forces and undercutting as causes, independent of fluvial forces, of bank failures in some stream systems. Specific seepage and pipeflow mechanisms that cause bank failure may never manifest themselves as transparent features on unstable banks. The objective of this research was to conduct more in-depth laboratory and field experiments to determine how groundwater flow mechanisms, potentially in combination with fluvial processes, affect the occurrence and timing of streambank erosion and failure. Current research activities include conducting three-dimensional soil column experiments to determine the occurrence and prevalence of different seepage erosion mechanisms (i.e., seepage gradient forces and undercutting) across a range of soil textures and cohesions and to identify typical undercut formations when seepage undercutting occurs. Seepage undercuts only formed in sands with a bulk density greater than 1.35 g/cm3 and in loamy sands with a bulk density greater than 1.50 g/cm3. For soils with greater clay content, seepage erosion undercuts may not occur under typical bulk densities. This research also monitored pore-water pressures in a streambank on Dry Creek, a tributary to Little Topashaw Creek located in Chickasaw County, Mississippi, before and during an induced seepage experiment. Seepage flow and erosion rates were measured in four separate experiments on three seeps and demonstrated the capability of seepage to rapidly destabilize streambanks, especially when acting in concert with processes that remove deposited material from the seepage undercut. Usually the erosion rate of cohesive soils from fluvial forces is computed using an excess shear stress equation, dependent on two major soil parameters: the critical shear stress and the erodibility coefficient. A submerged jet test apparatus is one method for measuring these parameters. In this study, a new miniature version of the jet test device and a seepage column were utilized to measure the erodibility of cohesive soils influenced by seepage. Erodibility of cohesive soils exponentially increased with higher seepage gradients. These laboratory and field experiments have further demonstrated the importance of considering seepage mechanisms relative to bank and hillslope stability. Groundwater forces can act over extended periods to destabilize banks between flow events, but specific seepage mechanisms become prevalent under certain streambank stratigraphy and hydrologic conditions. DA - 2011/// PY - 2011/// DO - 10.13031/2013.39206 ER - TY - JOUR TI - Comparison of subsurface and surface runoff phosphorus transport rates in alluvial floodplains AU - Mittelstet, Aaron R. AU - Heeren, Derek M. AU - Fox, Garey A. AU - Storm, Daniel E. AU - White, Michael J. AU - Miller, Ronald B. T2 - Agriculture, Ecosystems & Environment AB - Phosphorus (P) loading to streams can occur by both surface runoff and subsurface transport, with subsurface P transport often assumed negligible. Groundwater P concentrations in alluvial aquifers can be significant, especially in preferential flow paths (PFPs). The objectives of this research were to quantify subsurface P transport rates at two sites in northeastern Oklahoma and to compare them with surface runoff P transport rates derived from a hydrologic model, the Pasture Phosphorus Management Calculator (PPM Plus). Ozark ecoregion study sites were adjacent to the Barren Fork Creek and Honey Creek in northeastern OK, USA. Each site, instrumented with 24 observation wells, was monitored for several months for both groundwater levels and P concentrations. Using the flow and P concentration data, Monte Carlo simulations with Darcy's Law and a P transport rate equation were used to calculate the distributions of subsurface P transport rates across a transect within the well field containing a single identified PFP. Total subsurface P transport rates, through both the non-PFP flow domain and a single PFP, were estimated to be 0.04 kg year−1 and 0.03 kg year−1 for the Barren Fork Creek and Honey Creek field sites, respectively. Monte Carlo simulations for surface runoff P transport rates with PPM Plus resulted in average total P surface runoff transport rates of 0.07 kg year−1 for the Barren Fork Creek site and 0.08 kg year−1 for the Honey Creek site. For the groundwater at these floodplains, the P source was P-laden stream water flowing into the alluvial aquifer and a minimal quantity of P leaching from the surface. Results indicated that the subsurface P transport rates for small (3 ha) alluvial floodplain sites in the Ozark ecoregion were at least 0.03–0.04 kg year−1, although subsurface P transport rates may be higher in cases with greater numbers of PFPs and where the subsurface is connected to a larger P source. DA - 2011/5// PY - 2011/5// DO - 10.1016/j.agee.2011.04.006 VL - 141 IS - 3-4 SP - 417-425 J2 - Agriculture, Ecosystems & Environment LA - en OP - SN - 0167-8809 UR - http://dx.doi.org/10.1016/j.agee.2011.04.006 DB - Crossref KW - Alluvial floodplains KW - Hydrologic modeling KW - Phosphorus management KW - Preferential flow KW - Subsurface transport ER - TY - JOUR TI - Design and Application of a Direct-Push Vadose Zone Gravel Permeameter AU - Miller, R.B. AU - Heeren, D.M. AU - Fox, G.A. AU - Storm, D.E. AU - Halihan, T. T2 - Ground Water AB - A borehole permeameter is well suited for testing saturated hydraulic conductivity ( K sat ) at specific depths in the vadose zone. Most applications of the method involve fine‐grained soils that allow hand auguring of test holes and require a small water reservoir to maintain a constant head. In non‐cohesive gravels, hand‐dug test holes are difficult to excavate, holes are prone to collapse, and large volumes of water are necessary to maintain a constant head for the duration of the test. For coarse alluvial gravels, a direct‐push steel permeameter was designed to place a slotted pipe at a specific sampling depth. Measurements can be made at successive depths at the same location. A 3790 L (1000 gallons) trailer‐mounted water tank maintained a constant head in the permeameter. Head in the portable tank was measured with a pressure transducer and flow was calculated based on a volumetric rating curve. A U.S. Bureau of Reclamation analytical method was utilized to calculate K sat . Measurements with the permeameter at a field site were similar to those reported from falling‐head tests. DA - 2011/// PY - 2011/// DO - 10.1111/j.1745-6584.2010.00796.x VL - 49 IS - 6 SP - 920-925 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-80052945273&partnerID=MN8TOARS ER - TY - JOUR TI - Comparison of Aquifer Sustainability Under Groundwater Administrations in Oklahoma and Texas1 AU - Mittelstet, Aaron R. AU - Smolen, Michael D. AU - Fox, Garey A. AU - Adams, Damian C. T2 - JAWRA Journal of the American Water Resources Association AB - Mittelstet, Aaron R., Michael D. Smolen, Garey A. Fox, and Damian C. Adams, 2011. Comparison of Aquifer Sustainability Under Groundwater Administrations in Oklahoma and Texas. Journal of the American Water Resources Association (JAWRA) 1-8. DOI: 10.1111/j.1752-1688.2011.00524.x Abstract: We compared two approaches to administration of groundwater law on a hydrologic model of the North Canadian River, an alluvial aquifer in northwestern Oklahoma. Oklahoma limits pumping rates to retain 50% aquifer saturated thickness after 20 years of groundwater use. The Texas Panhandle Groundwater Conservation District’s (GCD) rules limit pumping to a rate that consumes no more than 50% of saturated thickness in 50 years, with reevaluation and readjustment of permits every 5 years. Using a hydrologic model (MODFLOW), we simulated river-groundwater interaction and aquifer dynamics under increasing levels of “development” (i.e., increasing groundwater withdrawals). Oklahoma’s approach initially would limit groundwater extraction more than the GCD approach, but the GCD approach would be more protective in the long run. Under Oklahoma rules more than half of aquifer storage would be depleted when development reaches 65%. Reevaluation of permits under the Texas Panhandle GCD approach would severely limit pumping as the 50% level is approached. Both Oklahoma and Texas Panhandle GCD approaches would deplete alluvial base flow at approximately 10% development. Results suggest periodic review of permits could protect aquifer storage and river base flow. Modeling total aquifer storage is more sensitive to recharge rate and aquifer hydraulic conductivity than to specific yield, while river leakage is most sensitive to aquifer hydraulic conductivity followed by specific yield. DA - 2011/3/4/ PY - 2011/3/4/ DO - 10.1111/j.1752-1688.2011.00524.x VL - 47 IS - 2 SP - 424-431 LA - en OP - SN - 1093-474X UR - http://dx.doi.org/10.1111/j.1752-1688.2011.00524.x DB - Crossref KW - alluvial aquifer KW - water law KW - water policy KW - groundwater management KW - MODFLOW KW - groundwater model KW - groundwater-river interaction KW - conjunctive use ER - TY - CONF TI - Assessing streambank stability of oklahoma ozark streams with rapid geomorphic assessments AU - Heeren, D.M. AU - Mittelstet, A.R. AU - Fox, G.A. AU - Storm, D.E. AB - Streams in the Ozark Ecoregion naturally meander and have a high degree of sinuosity. Changes in land use have resulted in accelerated rates of streambank erosion. Numerous benefits may be achieved from streambank stabilization, but more information is needed on the most critical locations for investing limited funds. Rapid geomorphic assessments (RGAs) are indices proposed to aid in prioritizing sites. This research (1) evaluated two RGAs, the Bank Erosion Hazard Index (BEHI) and the Channel Stability Index (CSI), on several stream sites along the Barren Fork Creek and Spavinaw Creek, and (2) developed a new RGA specific to the ecoregion. The performance of the RGAs was assessed based on lateral bank erosion estimated from five years of aerial photography. Correlations between the existing RGAs and lateral bank erosion were relatively low with coefficients of determination, R2, of 0.23 and 0.19 for CSI and BEHI, respectively. The two RGAs failed to indicate the same reaches as the most unstable. Primary limitations were not considering the streambank's cohesion and the difficulty in accurately assessing some metrics. Therefore, the Ozark Stream Erosion Potential Index (OSEPI) was developed by including parameters to account for bank cohesion and stream curvature. The OSEPI had the highest correlation (R2 of 0.31 for all sites; R2 of 0.46 for sites with similar soils) to measured streambank erosion and aided in prioritizing sites. C2 - 2011/// C3 - World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress DA - 2011/// DO - 10.1061/41173(414)408 SP - 3907-3916 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79960395760&partnerID=MN8TOARS ER - TY - JOUR TI - A Sociology: The Dynamics of Collectivities and Their Application to Social Change and Development AU - Jicha, Karl A. AU - Thompson, Gretchen H. T2 - RURAL SOCIOLOGY AB - Rural SociologyVolume 76, Issue 4 p. 587-590 A Sociology: The Dynamics of Collectivities and Their Application to Social Change and Development – By Kris Merschrod Karl A. Jicha, Karl A. Jicha North Carolina State UniversitySearch for more papers by this authorGretchen H. Thompson, Gretchen H. Thompson North Carolina State UniversitySearch for more papers by this author Karl A. Jicha, Karl A. Jicha North Carolina State UniversitySearch for more papers by this authorGretchen H. Thompson, Gretchen H. Thompson North Carolina State UniversitySearch for more papers by this author First published: 05 December 2011 https://doi.org/10.1111/j.1549-0831.2011.00065_3.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume76, Issue4December 2011Pages 587-590 RelatedInformation DA - 2011/12// PY - 2011/12// DO - 10.1111/j.1549-0831.2011.00065_3.x VL - 76 IS - 4 SP - 587-590 SN - 0036-0112 ER - TY - JOUR TI - Exploring fecal indicator bacteria in a constructed stormwater wetland AU - Hathaway, J. M. AU - Hunt, W. F. AU - Graves, A. K. AU - Bass, K. L. AU - Caldwell, A. T2 - WATER SCIENCE AND TECHNOLOGY AB - 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. DA - 2011/// PY - 2011/// DO - 10.2166/wst.2011.539 VL - 63 IS - 11 SP - 2707-2712 SN - 1996-9732 KW - fecal coliform KW - microbe KW - sediment KW - stormwater KW - wetland ER - TY - JOUR TI - Effects of two different ozone doses on seawater recirculating systems for black sea bream Acanthopagrus schlegeli (Bleeker): Removal of solids and bacteria by foam fractionation AU - Park, Jeonghwan AU - Kim, Youhee AU - Kim, Pyong-Kih AU - Daniels, Harry V. T2 - AQUACULTURAL ENGINEERING AB - Foam fractionators, with and without additional ozonation, were evaluated for their effect on solids removal (suspended solids, SS; volatile suspended solids, VSS; dissolved organic carbon, DOC), particle size distribution of the foam in seawater recirculating systems during a 44-day experimental period. The effect of ozone on heterotrophic bacteria was also quantified in the entire system. Three separate but identical recirculating systems (4.5 m3 system volume) with foam fractionators (300 mm in diameter, 3 m in height) were used in this study. One system (Control: CS) did not receive ozone, while the other two systems were ozonated at a rate of either 20 g ozone/day (T 20) or 40 g ozone/day (T 40) per kg of feed applied, respectively. A total of 107 kg of black sea bream Acanthopagrus schlegeli (Bleeker) with an average weight of 334.5 g was stocked into each system. Daily feeding rate was 1% of total body weight. The solids enrichment factor (EF = Cc/Ci, where Cc = concentration in foam condensate, Ci = concentration in inlet water) in T 40 was 10 times more dilute than the factors in CS and T 20. However, due to the higher volume of the foam (>10 times) in T 40, the removal rates of SS, VSS and DOC were the highest in T 40, but were not significantly different from T 20 (P > 0.05). The mean particle sizes at the 90% cumulative removal point decreased with ozonation, 71.2 ± 15.9, 57.9 ± 10.2 and 48.0 ± 10.2 μm in CS, T 20 and T 40, respectively. The overall mean particle diameter of solids in the foam decreased as ozonation increased, with values of 29.4 ± 4.4, 23.9 ± 3.8 and 20.5 ± 3.7 μm in CS, T 20 and T 40. Numbers of heterotrophic bacteria in the inlet were 6.21 ± 4.93 × 105 CFU/mL, 0.29 ± 0.19 × 105 CFU/mL and 0.30 ± 0.29 × 105 CFU/mL in CS, T 20 and T 40, declining sharply with the addition of ozonation. As the number of the bacteria in the inlet decreased, the bacteria in the foam and the removal rate greatly decreased with increasing ozonation. However, EFs in T 20 (76.4) and T 40 (14.5) were higher than that in CS (12.2), and the T 20 showed significantly higher EF (P < 0.05). Therefore, based on the EF, ozonation improved the removal efficiency of heterotrophic bacteria, even at the lowest concentration. DA - 2011/1// PY - 2011/1// DO - 10.1016/j.aquaeng.2010.11.001 VL - 44 IS - 1 SP - 19-24 SN - 1873-5614 KW - Ozonation KW - Seawater recirculating aquaculture system KW - Foam Fractionator KW - Solids KW - Bacteria KW - Black sea bream ER -