Progress 10/01/03 to 09/30/09
Outputs
OUTPUTS: A field study was conducted to assess movement of pollutants under natural conditions from two sites, one with a sandy soil and one with an organic layer below 50 cm depth, within an abandoned agricultural field into drainage ditches. The sites were visited once or twice a month for 11 months. During each visit, soil water content, soil water potentials in the unsaturated and saturated zones, water table level, and redox potential at different depths were measured. In addition, soil solution samples were collected by tension sampler (lysimeters) and analyzed for pH, ammonium, nitrate, phosphorus, sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and total organic carbon (TOC). A field experiment was conducted at the site with sandy soil to assess lateral movement of nitrate and bromide (Br) through the capillary fringe. Ten L of a solution containing nitrate and Br were applied above the water table through an auger hole. Using tension samples installed at different depths and locations, lateral distributions of both solutes were monitored along the flow path for more than 80 days. In the laboratory, a 240-cm long, 115-cm high, and 8.5-cm wide rectangular column, with its front face constructed of clear polycarbonate was packed with clean sand. After establishing a water table, a solution containing a red tracer dye was applied to one location on the surface of the column and the path of the dye was recorded intermittently by a video camera. The experiment was repeated a few times using different dye solutions and application locations to simulate water movement from septic systems through the unsaturated and saturated zones in areas with a shallow water table. Fate and transport of nitrate through the capillary fringe was also assessed using 240-cm, 60-cm high, and 25-cm wide columns packed with different soils. A solution containing nitrate and Br was applied to one side of the column and allowed to move laterally through the column under a constant water table. Soil redox potentials were measured and soil solution samples were collected at different depths and locations along the column. In a separate set of experiments, movement of a tracer dye and E. coli that could fluoresce under UV light through a 90-cm wide, 50-cm high, and 8.5-cm wide column packed with sand was assessed under different scenarios. Also, assessed were the extent and rate of redox potential in the unsaturated zone, capillary fringe, and saturated zone created within the same size columns packed with four different soils. In a different study, transport and survival of E. coli through a sandy soil were evaluated using 15-cm in diameter and 65 cm long sand columns. Three depths to water table; 30, 45, and 60 cm; were maintained in the columns using five replications. A 200-mL solution containing E. coli was applied to the surface of each column daily and a water sample was collected from the top of the water table to determine the number of microbes that could reach the water table. In addition to the above studies, the suitability of an animal waste-based root zone mixture for putting green construction was evaluated through a laboratory study. PARTICIPANTS: The following individuals were involved in the conduct of the research reported here. David Lindbo was a Co-PI on the projects to assess transport of E. coli through a sandy soil as impacted by depth to water table, and the lateral transport of solutes through the capillary fringe. He was a Co-Advisor for Christopher Stall, a MS degree graduate. Michael Vepraskas was a Co-PI on the project to assess fate and transport of chemicals and microbial pollutants through the unsaturated zone, capillary fringe, and saturated zone continuum. He was a Co-Advisor for Sergio Abit, a MS and PhD graduate. Michael Hoover was consulted regarding various aspects of the project. Charles Peacock was a Co-PI on the project to assess the suitability of an animal-waste based mixture for golf green construction. Christopher Stall was a graduate student and completed his MS degree in summer of 2008. He conducted the laboratory study to assess transport of E. coli in a sandy soil as impacted by depth to water table. Sergio Abit was a graduate student and completed his MS degree in 2005 and his PhD in 2009. For his MS degree, he conducted the field experiments assessing transport of nutrients from an abandoned agricultural field into open drainage ditches and lateral transport of nitrate and bromide through the capillary fringe. For his PhD, he conducted a series of laboratory experiments assessing fate and transport of chemical and microbial pollutants through the unsaturated-capillary fringe-saturated zone continuum. The results of these studies were presented to scientific communities through presentations at Soil Science Society of America, Kirkham Conference, Wetland Scientists meetings as well as to professionals and regulatory officials through workshops and conferences, such as the Annual On-Site Conference conducted through the NC Agricultural Extension Service in Raleigh, NC. TARGET AUDIENCES: The target audiences were research/education scientists, consulting professionals, and regulatory officials. PROJECT MODIFICATIONS: The first two objectives of the study were investigated using three septic systems through a project that was initiated prior to the start of this project. A research proposal for expanding the study to include more septic systems/sites was submitted to USDA, but did not receive funding. A draft report directly related to these objectives entitled "Movement of pollutants from septic systems and performance of riparian buffers in suburban settings," WRRI Project Number 50296, was submitted to the Water Resources Research Institute of the University of North Carolina in July 2004. A column study was conducted to simulate contribution of E. coli from septic systems to groundwater as impacted by the depth to water table. Evaluation of the potential lateral transport of pollutants through the capillary fringe (Objective 3) was expanded substantially. A field investigation was conducted to determine the fate and transport of nitrate under natural conditions, and a series of laboratory column studies was conducted to assess redox properties of the capillary fringe as well as fate and transport of nitrate, phosphorus and E. coli in the unsaturated zone-capillary fringe-saturated zone continuum. A short study to assess the potential use of an animal waste soil mixture for putting green was conducted during this period. This project was not included in the original Project Outline.
Impacts
The field monitoring study revealed that the source of chemicals entering drainage ditches or streams following storm events is not groundwater discharge into them. Assessment of lateral transport of nitrate and bromide (Br) within the capillary fringe and the upper part of groundwater revealed that chemicals entering capillary fringe can travel horizontally a substantial distance before they are carried to below the water table by vertical percolation due to rainfall infiltration at the soil surface. While both nitrate and Br that were applied to the soil at the source were present in the capillary fringe at 320 cm distance from the application spot 80 days after solute application, only Br was present below the water table. This indicates that while denitrification may be substantial in the saturated zone, capillary fringe remains aerobic allowing lateral transport of nitrate to streams and drainage ditches. Laboratory studies of the fate and transport of a number solutes (nitrate, phosphorus, and bromide) and E. coli also revealed that pollutants entering the vadose zone move vertically down until reaching the capillary fringe. Then, due to the hydrologic nature of the capillary fringe, both solutes and microbes can be retained and transported laterally until being pushed down to below the water table by percolating rain or irrigation water. Assessment of the redox potential within the unsaturated, capillary fringe, and saturated zone showed that while the upper part of the capillary fringe can remain aerobic, the lower portion of the capillary fringe and the zone below the water table can become anaerobic, which can promote denitrification providing that a source of organic carbon is present. Although these findings need to be verified through a series of field investigations, the results point to the need for monitoring the capillary fringe in addition to groundwater for assessing pollutants fate and transport for environmental monitoring. The results of the column investigation of the fate and transport of microbes as impacted by depth to water table indicate that 30 cm of separation distance between the bottoms of septic system trenches and water table may not be adequate for treating microbes in sandy soils with a high water table. For these soils, a minimum of 60 cm of separation distance is needed to attenuate microbes. These results must be verified through a set of controlled field experiments and the findings can be used as guidelines for developing regulations for the use of septic systems in areas with a high water table.
Publications
- Amoozegar, A., Peacock, C. and Niewoehner, C. (2009). Suitability of an animal waste-based root zone mixture for putting green construction. Int. Turfgrass Soc. Res. J. 11:1033-1040. Abit, S. M. 2009. Hydrologic Effects on Subsurface Fates and Transport of Contaminants. Ph.D. Dissertation. Department of Soil Science. North Carolina State University. At: http://www.lib.ncsu.edu/theses/available/etd-06122009-145828/unrestri cted/etd.pdf.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Lateral transport of a tracer dye and E. coli that could fluoresce under UV light through the capillary fringe and the zone immediately below the water table was evaluated using sand packed in a 90- cm long, 50-cm high, and 8.5-cm wide column. After establishing a water table and allowing lateral flow of water from left to right, a solution containing a tracer dye and E. coli was applied through a small area on the left side near the surface of the column. Movement of dye and transport of E. coli were visually inspected under natural and UV light, respectively. In another set of experiments the extent and rate of soil reduction in the capillary fringe and the zone below the water table as impacted by lateral pore water velocity were investigated. For this study, a mineral and an organic soil were packed in 90- cm long, 50-cm high, and 8.5-cm wide columns. Platinum (Pt) electrodes (also known as redox probes) attached to a data logger and tensiometers were installed at various depths and locations within each column. The rate of water flow through the saturated portion of each column was varied by adjusting the water levels on the two sides of the column. The soil water potential and the electrical potential of the soil at various locations above and below the water table were measured using the tensiometers and the Pt electrodes, respectively. In the third set of experiments, transport of nitrate-nitrogen through sand, an inorganic soil, and an organic soil packed in 240-cm long, 60-cm high, and 25-cm wide columns was investigated under different lateral flow conditions. Using large columns (15-cm diameter and 60-cm long), assessment of survival and transport of E. coli in a sandy soil, as impacted by depth to water table, was completed. A sandy soil collected from an agricultural field was packed in the columns and a water table was established at 30, 45, and 60 cm below the level of the soil in each column using five replications. A 200 mL solution containing E. coli was applied to the surface of the soil in each column once a day, and an outflow from the top of the saturated zone was collected for analysis. The capacity of crumb used tires (i.e., ground tire) and tire chips (currently being used as a replacement for gravel in septic system trenches) for removing phosphorus was assessed using a batch and column study. PARTICIPANTS: David Lindbo, Associate Professor; Michael Vepraskas, Professor; Christopher Niewoehner, Research Assistant; Sergio Abit, Ph.D. Degree Graduate Research Assistant; and Christopher Stall, M.S. Degree Graduate Research Assistant TARGET AUDIENCES: In addition to scientific community, the target audience includes federal, state, and local health and environmental officials in charge of on-site waste management as well as protection of water quality; soil science, engineering, and environmental consultants; and the general public interested in water quality and waste management. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In the first set of experiments, up to 100% of the surface applied microbes and solutes moved vertically down through the unsaturated (vadose) zone, but they were transported laterally within the capillary fringe above the water table. The results of the second set of experiments assessing redox and soil water potentials at various depths and locations within different soils show that at relatively low organic matter content pore water velocity has a noticeable effect on the extent and rate of soil reduction. Also, the results indicate that parts of capillary fringe can remain aerobic for periods exceeding 14 days even though the soil in the capillary fringe is almost saturated. The preliminary results of the third set of experiments assessing transport of nitrate show that while nitrate may be lost below the water table through denitrification, it persists and is transported laterally within the capillary fringe. The results of the column study assessing the impact of water table on microbial transport indicate that microbes can travel rapidly through 30 cm of unsaturated soil (including the capillary fringe) between the surface of application (e.g., bottom of trenches in a septic system) and water table. Increasing the vertical separation distance between the point of application and water table to 60 cm, however, has a pronounced effect on reducing the number of microbes entering the water table. Finally, evaluation of the crumb tire produced from used tires revealed that crumb tire has the ability to absorb phosphorus (P), but its capacity to fix P must be investigated. If the results of the laboratory studies assessing transport of chemicals and microbial pollutants through the capillary fringe hold true under field conditions, new protocols for collecting soil solution and ground water samples must be developed to assess lateral transport of various pollutants from agricultural fields as well as waste disposal facilities. Regulations regarding septic system installation in areas with relatively shallow water table must also be reexamined to ensure microbial pollutants from septic systems installed in areas with shallow water table do not enter ground water. If tire chips and tire crumbs can fix P and other pollutants, their use in septic systems and other systems (e.g., artificial soil for golf courses) can be expanded as a means of managing used tires. The results obtained in the studies listed above have been disseminated to scientific and professional communities through a number of presentations at various meetings, including those of the Kirkham Conference, Soil Science Society of America (SSSA), Society of Wetland Scientists, Soil Science Society of North Carolina, North Carolina On-Site Conference, and the National Onsite Wastewater Recycling Association.
Publications
- Abit, S. M., Vepraskas, M. J., Amoozegar, A. and Niewoehner, C. P. 2008. Soil and hydrologic effects on reduction rates and nitrate fate in a vadose zone, capillary fringe and shallow groundwater continuum. Abstract book for the 1st International Conference on Hydropedology July 28-31, Penn State Univ., University Park, PA.
- Abit, S.M., Amoozegar, A., Vepraskas, M. J., and Niewoehner, C. P. 2008. Solute transport in the capillary fringe and shallow ground water: Field evaluation. Vadose Zone J. 7:890-898
- Abit, S. M., Amoozegar, A., Vepraskas, M. J., and Niewoehner, C. P. 2008. Fates of nitrate in the capillary fringe and shallow ground water in a sandy soil drained by ditches. Geoderma 146:209-215.
- Amoozegar, A., Niewoehner, C., and Lindbo, D. 2008. Water flow from trenches through different soils. J. of Hydrologic Engr., ASCE 13(8): 655-664.
- Stall, C., Amoozegar, A., Lindbo, D., Graves, A., and Rashash, D. 2008. Microbial fate and transport in a seasonally saturated North Carolina Coastal Plain soil. In Water: Manage, Reuse, Renew. Proceed. of the 17th Annual Conference of the National Onsite Wastewater Recycling Association (NOWRA). Available on CD from NOWRA, Santa Cruz, CA.
- Stall, C. J. 2008. Microbial fate and transport in a seasonally saturated North Carolina Coastal Plain soil. M.S. Thesis. North Carolina State University, Raleigh, NC.
- Abit, S. M., Amoozegar, A., Vepraskas, M. J. and Niewoehner, C. P. 2008. Fate and transport of nitrate and microbes in a simulated vadose zone, capillary fringe, and shallow groundwater continuum. CSA Joint Annual Conference Abstracts. Houston, Texas, Oct 5-9, 2008.
- Abit, S. M., Amoozegar, A., Vepraskas, M. J. and Niewoehner, C. P. 2008. Storm effects on nutrient concentrations in the vadose zone, shallow groundwater and ditches prior to wetland restoration of a Carolina Bay. Abstracts for 2008 Society of Wetland Scientists Annual Meeting, May 26-30 at Washington, DC. Available at http://www.sws.org/2008_meeting/All%20Abstracts-May16.pdf.
- Abit, S. M., Vepraskas, M. J., Amoozegar, A. and Niewoehner, C. P. 2008. The capillary fringe: Its impact on the wetland hydrology technical standard. Abstracts for 2008 Society of Wetland Scientists Annual Meeting, May 26-30 at Washington, DC. Available at http://www.sws.org/2008_meeting/All%20Abstracts-May16.pdf.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: Fate and transport of nitrate through the capillary fringe and the saturated zone immediately below the water table were evaluated in the laboratory using two 240-cm long, 60-cm high, and 25-cm wide flow cells. The front face of each flow cell (hereafter referred to as column) was covered with clear polycarbonate sheet and two soils containing different amounts of sand and organic matter were packed in the columns. Tension samplers and platinum electrodes (referred to as redox probes) were installed at different depths at four locations along each column. The tension samplers were for collecting soil solution from the capillary fringe and the saturated zone below the water table, and the redox probes were for measuring redox potential. A water table was established by maintaining constant levels of water at the beginning and end of the column. The constant level of water at the inlet was slightly higher than the water level in the outlet to allow water to move along the
length of the column. A solution containing nitrate and bromide was passed horizontally through each column and the levels of water in the inlet and outlet were varied to simulate different pore water velocity along the column. The concentration of each of nitrate-nitrogen (N) and bromide (Br) in the inflow solution was 15 mg/L. Soil solution samples were collected by the tension samplers and redox potentials were measured using the platinum electrodes. The samples were analyzed for nitrate-N and Br. In another laboratory study transport of Escherichia coli (E. coli) as impacted by depth to water table was evaluated in a laboratory column study. Fifteen-cm diameter and 75-cm long columns constructed of polyvinylchloride (PVC) pipe were packed with soil from the Bt horizon of a Norfolk soil. The depth of soil in each column was 65 cm. Using five replications, a water table was established at 30, 45, and 60 cm below the soil surface in the columns. A total of 200 mL of an artificial
wastewater containing a number of solutes and inoculated with a culture of E. coli (ATTCC number 11775) was applied to the top of each column daily for 130 days. A 100-mL water sample was then collected from top of the saturated zone daily and selected number of samples were analyzed for E. coli frequently.
PARTICIPANTS: David Lindbo, Associate Professor; Michael Vepraskas, Professor; Christopher Niewoehner, Research Assistant; Sergio Abit, Ph.D. Degree Graduate Research Assistant; and Christopher Stall, M.S. Degree Graduate Research Assistant
Impacts
The preliminary results for the large column study indicated that the capillary fringe remained aerobic, but reduced conditions, indicating anaerobic conditions, were developed in the saturated zone below the water table. The amounts of nitrate-N and Br in the capillary fringe remained comparable, suggesting limited denitrification. Below the water table, however, no nitrate-N was detected while Br levels remained relatively high. Preliminary results of the second study indicated that E. coli traveled rapidly into the ground water with little treatment when water table was at 30 cm, but treatment was much greater when water table was at 60 cm below the soil surface.
Publications
- Surbrugg, J. E., and A. Amoozegar. 2007. Distribution of inorganic chemicals under a small community on-site wastewater disposal system. In Proc. of the 11th Individual and Small Community Sewage Systems Conference. ASABE Publication No. 701P1107. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
- Amoozegar, A., K. Martin, C. Niewoehner, and D. Lindbo. 2007. Wastewater infiltration and water movement around trenches of septic systems. In Proc. of the 11th Individual and Small Community Sewage Systems Conference. ASABE Publication No. 701P1107. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
- Amoozegar, A., D. L. Lindbo, and C. P. Niewoehner. 2007. Ground water mounding under large systems in areas with shallow water table. In Proc. of the 11th Individual and Small Community Sewage Systems Conference. ASABE Publication No. 701P1107. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
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Progress 10/01/05 to 09/30/06
Outputs
A series of laboratory experiments was conducted to simulate water flow from septic system trenches through the unsaturated and saturated zones in areas with a shallow water table. A rectangular column (approximately 235-cm long, 115-cm tall, and 8.5 cm wide), with its front face made from clear polycarbonate, was packed with uniform fine sand. Two sections of 2-inch perforated well casing were installed at the two sides of the column to simulate drainage ditches. To create a zone of saturation, constant levels of water were maintained in the two simulated drainage ditches. To establish lateral flow in the saturated zone through the column the water level in the left ditch was maintained at a few cm higher than the right ditch. Three of the experiments will be presented here. In the first experiment, a 45-cm wide and 20-cm deep trench, filled with gravel, was installed at the top of the left half of the column. A 1-L dose of a blue tracer dye solution was applied to
this trench followed by other 1-L doses of water for several days. In the second simulation, two trenches, each 30-cm wide and 20-cm deep, were installed on top of the column. The distance between the two trenches from center to center was approximately 90 cm. A blue tracer dye solution was applied to the left side ditch and a red tracer dye solution was applied to the right side in one-L doses for several applications. For the third experiment, the column was repacked and a red dye solution was applied continuously at a low rate to five locations at the bottom of a 30-cm wide and 20 cm deep trench that was installed on the left half side of the column. In all three experiments the dye solutions moved vertically through the unsaturated zone above the capillary fringe, but moved laterally within the capillary fringe with little interaction with the saturated zone below the water table. If the results of this laboratory study prove to be true under various field conditions, new
protocols must be developed to sample the soil solution below the trenches in areas with shallow water table.
Impacts
The results of the laboratory sand column experiments show that solute entering capillary fringe may move laterally with little interaction with the saturated zone. Since the capillary fringe may remain aerobic, little to no denitrification may take place in it. Also, little to no water may enter a sampling well during ground water sample collection. Movement of pollutants in the capillary fringe and ground water sampling methods need to be investigated in different geologic material.
Publications
- Amoozegar, A., C. P. Niewoehner, and D. L. Lindbo. 2006. Lateral movement of water in the capillary fringe under drainfields. In Wastewater Treatment through Integrated Wastewater Management. Proceedings of the Technical Education Conference. National Onsite Wastewater Recycling Association. Edgewater, MD.
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Progress 10/01/04 to 09/30/05
Outputs
A rectangular column (approximately 235-cm long, 115-cm tall, and 8.5 cm wide), with its front made from a clear polycarbonate sheet, was packed with fine sand. Two sections of 2-inch perforated well casing were installed at the two sides of the column to simulate drainage ditches, and six outlets were installed at the bottom of the column to determine water table level. A 30-cm wide and 20-cm deep cut, filled with gravel, was installed at one location on the top part of the column to simulate a septic system trench. Lateral ground water flow was established by maintaining a constant level of water in one of the perforated pipes at a slightly higher level than the other. A red dye solution was applied to the gravel packed cut (simulated trench) under different scenarios and the movement of the dye solution was recorded intermittently by a video camera for several days. The red dye solution applied to the simulated trench moved vertically down until reaching the
capillary fringe. Then, the dye moved laterally within the capillary fringe until it was forced vertically down by percolating water applied to the surface as rainfall/irrigation. A solute transport experiment was conducted in a sandy soil drained by relatively shallow ditches at Juniper Bay, NC. Ten L of a solution containing potassium bromide (approximately 6100 mg/L Br) and magnesium nitrate (approximately 1110 mg/L nitrate) was applied to the bottom of a cylindrical auger hole dug to within 10 cm of the top of the capillary fringe at the time of application. Twenty nests of tension samplers (tension lysimeters), installed at 45, 60, 75, 90 and 105 cm below the soil surface at radial distances of 20, 60, 120, 220 and 320 cm from the auger hole along the general direction of the ground water flow, were used to extract soil solution samples from the capillary fringe and the top of the shallow ground water. Soil solution and ground water samples were collected by the tension samplers
3, 6, 10, 17, 20, 28, 33, 38, 42, 49, and 59 days after solution application and analyzed for nitrate and bromide. Both bromide and nitrate that entered the capillary fringe around the application site remained and moved laterally in the capillary fringe until they were pushed into the shallow water table by fluctuating water table following rain events. Of the total amounts of Br detected 59 days after the solution application at 320 cm from the application spot almost 50 percent was in the capillary fringe. The relative concentrations (ratio of the concentration in soil solution to the inflow solution) of nitrate in the capillary fringe were similar to the corresponding relative concentrations of bromide. In the shallow groundwater, on the other hand, the relative concentration of nitrate was less than the bromide, indicating loss of nitrate perhaps due to denitrification.
Impacts
The results of the laboratory sand column and field solute transport studies show that solute entering capillary fringe may move laterally without entering the water table. Overall the results indicate the need for assessing movement of pollutants in the capillary fringe in different geological materials, as well as developing protocols for assessing lateral transport of chemicals above the water table.
Publications
- Abit, S., Jr. 2005. Evaluation of subsurface solute transport and its contribution to nutrient load in the drainage ditches prior to a restoration of a Carolina Bay. MS Thesis. North Carolina State University, Raleigh, NC.
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Progress 10/01/03 to 09/30/04
Outputs
One small box (30- by 52- by 1-cm) and one large box (110- by 235- by 9-cm), each with a clear face made from polycarbonate, were constructed in the laboratory. A section of perforated polyvinyl chloride (PVC) pipe was inserted at each side of each column to simulate drainage ditches. Each box was packed uniformly with fairly uniform clean sand. A water table was established in each sand column by maintaining a constant level of water in the two perforated pipes at the two ends of the column. By varying the level of water in one perforated pipe we create a hydraulic gradient forcing water to move across the column. To test the system, a red dye solution and a separate blue dye solution were applied at different locations along the flow path to trace the streamlines in the system. Tracer dye solutions will be used to assess water movement through both saturated zone and unsaturated zone above the simulated water table under varying conditions. A field study was
initiated to assess the movement of pollutants under natural conditions at two locations with different soils within a large old agricultural field with a high water table. The soil at one location is sandy to at least 2 m depth, while at the second location an extensive organic layer is present below approximately 50 cm depth. At each location 11 tension samplers were installed at 15-cm depth intervals from 30 to 180 cm depth. In addition to the tension samplers, seven modified piezometers and three wells were installed at each location for collecting ground water samples and measuring submergence potential at various depth intervals below the water table. Two five-segmented time domain reflectometry (TDR) rods, and 8 tensiometers (15- to 120-cm long) were installed for measuring soil water content and soil water pressure head, respectively. An extra well for continuously monitoring the water table was also installed at each location. At the site with mineral soil, 5 redox probes
were installed at each of 25 and 60 cm depths. At the site with the organic layer, 5 redox probes were installed at each of 25, 60, and 90 cm depths. Soil solution, ground water samples, and water samples from ditches in the vicinity of the monitoring locations were collected and are being analyzed. Sampling from the tension samplers, wells, and piezometers will be continued biweekly.
Impacts
The results of the sand column study will provide basic information regarding vertical movement of pollutants within the vadose zone and lateral movement of pollutants through the capillary fringe and below the water table at sites with a shallow water table. The field investigation will show how pollutants move into ditches from the fields with sandy soil and high water table.
Publications
- Amoozegar, A., S. Warren, C. Niewoehner, W. Robarge, M. Hoover, D. Hesterberg, and R. Rubin. 2003. Effect of graywater on soil hydraulic properties. p. 231-240 In K. R. Mankin (ed.) Proc. of the 10th National Symp. on Individual and Small Community Sewage Systems. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
- Morey, A. E., and A. Amoozegar. 2004. Use of septic systems in sandy soils with a shallow water table. p. 419-431. In K. R. Mankin (ed.) Proc. of the 10th National Symp. on Individual and Small Community Sewage Systems. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
- Warren, S. L., A. Amoozegar, W. P. Robarge, C. P. Niewoehner, W. M. Reece. 2004. Effect of graywater on growth and appearance of ornamental landscape plants. p. 647-654. In K. R. Mankin (ed.) Proc. of the 10th National Symp. on Individual and Small Community Sewage Systems. Am. Soc. Agric. Am. Soc. Agric. Engr., St. Joseph, MI.
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