• Addressing State Funding Assistance Through the Arizona State Aquatic Nuisance Species Management Plan: An Exercise in Policy Writing.

      King, Chad Eric.; Fitzsimmons, Kevin (The University of Arizona., 2002)
      Aquatic nuisance species (ANS) represent a growing problem in Arizona that is receiving little funding attention. With the objective of addressing this problem in a coordinated manner between state and federal agencies, the task of writing the Arizona State Aquatic Nuisance Species Management Plan was undertaken, this process and its results will be discussed. Section 1204 of the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (P.L. 101-646), provides opportunity for federal cost-share upon adoption of a state management plan. Methodology included gathering input towards reworking an early draft of the plan at a number of meetings, including the Lower Colorado Giant Salvinia Task Force, the Salvinia molesta National Convention, and Southwest Vegetation Management Association, and researching the format and process used in writing plans recently adopted in other states. Developments in management needs were incorporated, several of the plan's tasks were initiated and the plan was presented to agency members for comments and review. The resulting management plan is now ready to be signed into action, requiring approval by the state governor as a final step towards providing additional funds to fight ANS.
    • Adsorption/desorption of phenols on the Pima clay loam soil

      Bohn, H. L.; Yiannakakis, Alexandros Emmanuel, 1959- (The University of Arizona., 1988)
      A linear distribution isotherm described the sorption/desorption of four phenols on the Pima clay loam soil. The linear distribution coefficients for 2,4-dichlorophenol, 2-chlorophenol, phenol and 2,4,6-trichlorophenol were 3.61, 2.93, 0.87, and 0.79. Ionization of the phenols affected their relative distribution order. Hydrogen bonding of phenols to exposed mineral sites accounted for the greater measured sorption than was predicted. The effect of solid concentration on the distribution of phenols was tested over a 10-fold soil/solution range. When a log transformation was performed on the data, a highly significant inverse relationship existed between the distribution of phenols and the soil/solution ratio. A 3-fold increase in the dissolved organic carbon in solution was associated with the decrease in the distribution coefficient. A 3-fold increase in the fraction organic carbon in the soil occurred when dry sludge solids were added to the Pima soil. A substantial increase in the dissolved organic carbon in solution was associated with the addition of sludge solids to the soil. (Abstract shortened with permission of author.)
    • Andisols of the San Francisco Volcanic Field, Arizona

      Hendricks, David M.; Chen, Chuangming, 1960- (The University of Arizona., 1988)
      Six pedons derived from volcanic cinders from the San Francisco Volcanic Field near Flagstaff, Arizona, were studied to evaluate their physical, chemical, and mineralogical properties for inclusion in the proposed soil order Andisol. All the pedons meet the requirements for the Andic soil properties and they are thus classified as either Typic Ustivitrand or Melanic Ustivitrand Subgroups of Andisol Order. The proposed classification is discussed with respect to the guidelines presented in the ninth International Committee of Classification on Andisols (ICOMAND) letter.
    • Application of the Hillslope Erosion Model to predict annual sediment yield in Southwest New Mexico.

      King, Chad Eric.; Fitzsimmons, Kevin (The University of Arizona., 2002)
      The Big Burro Mountains in southwest New Mexico has been undergoing a decrease in herbaceous vegetation and an increase in woody vegetation. Through numerous unnamed ephemeral drainages this area contributes a significant amount of sediment into Mangas Creek, which is a tributary of the Gila River. In 2004, a prescribed burn was conducted to remove the woody vegetation and encourage the growth of herbaceous cover vegetation to reduce the amount of hillslope erosion. The Hillslope Erosion Model was utilized to predict sediment yield occurring in both a burned area and a nearby unburned area. Erosion bridges were established onsite to measure sediment yield. A data logging rain gauge was also located at the monitoring site to measure rainfall duration and intensity. Preliminary data indicates that the Hillslope Erosion Model was found to be a reliable tool for predicting hillslope erosion following rain events greater than one inch.
    • The Assessment of Escherichia coli as an Indicator of Microbial Quality of Irrigation Waters used for Produce

      Rock, Channah; Brassill, Natalie A.; McLain, Jean E.; Gerba, Charles; Nolte, Kurt (The University of Arizona., 2013)
      Escherichia coli is a bacterial species that lives in the gut of all warm-blooded animals, fish, birds as well as reptiles and is commonly used as an indicator of fecal contamination in water. This project assessed currently used culture based media for the detection of E. coli in irrigation waters used in Arizona and California, and will present recommendations towards the most reliable media for the evaluation of irrigation waters used for produce. Currently, no microbial indicator standards exist for irrigation waters used for produce production in the United States. The produce industry suggests that the recreational water standard guideline (126 E. coli/100 ml) established by the United States Environmental Protection Agency (USEPA) be used. There is concern that the false positive rate of E. coli detection may be high in these waters giving false indications of the level of risk from enteric pathogens. This project evaluated three commercially available media for E. coli detection to test irrigation waters from three agricultural areas (Yuma and Maricopa, AZ and Imperial Valley, CA) and then assessed false positive rates by utilizing Polymerase Chain Reaction (PCR) and DNA sequencing of the bacterial isolates. The media that were chosen for evaluation were (1) MI Agar, (2) IDEXX Colilert Quanti-Tray® and (3) m-ColiBlue24® broth, all evaluation media accepted by the USEPA and widely used in the monitoring of irrigation water quality by the produce industry. Four hundred and fifty 1-L irrigation water grab samples were collected between March 2012 and November 2012. The samples were analyzed for both cultural counts and water quality parameters including temperature, salinity and pH. Isolates positive and negative for E. coli were then selected and assessed utilizing PCR and DNA sequencing. The false positive rate of each method was found to be high, with MI Agar, m-ColiBlue24® broth and the IDEXX Colilert Quanti-Tray® at an accuracy of 67%, 72%, and 51% respectively. A false positive result is reported when presumptive E. coli sub cultured from the media is found to be non-E. coli through molecular analysis. Overall the IDEXX Colilert Quanti-Tray® performed at a greater rate of accuracy than the other two media evaluated, however, high false positive rates may lead to inaccurate assessment of water quality.
    • Attenuation of constituents from paper-pulp mill wastewater ponded on clay soil under natural environmental conditions

      Larson, Robert Blake.; Fuller, W. H. (The University of Arizona., 1986)
      The general purpose of this research was to determine the effects of paper-pulp mill wastewater disposal on the quality of the soil, . vegetation, groundwater, and environment in north central Arizona. Analytical laboratory procedures were used to determine the physical, chemical, and biological properties of the soil, vegetation, and water samples. Analysis of Variance was computed on soil, water, and plant analytical data to determine the significance of; downward distribution of wastewater constituents in clay soils under natural environment and ponded conditions; the heavy metal contents of natural and ponded vegetation in the area; and any changes in the environments surrounding and water sources due to disposals for the past 23 years. There was very slight movement of paper-pulp mill wastewater constituents into the clay soil below the disposal basin. Vegetation was not altered by irrigation with SWFI paper-pulp mill wastewater, either with respect to heavy, trace, or common ions or growth responses.
    • Batch and Column Transport Studies of Environmental Fate of 3-nitro-1,2,4-triazol-5-one (NTO) in Soils

      Dontsova, Katerina; Brusseau, Mark; Mark, Noah William; Dontsova, Katerina; Brusseau, Mark; Curry, Joan (The University of Arizona., 2014)
      NTO (3-nitro-1,2,4-triazol-5-one) is one of the new explosive compounds used in insensitive munitions (IM) and developed to replace traditional explosives, TNT and RDX. Data on NTO fate and transport is needed to determine its environmental behavior and potential for groundwater contamination. In this study, we measured how NTO in solution interacts with different types of soils and related soil properties to transport and fate behavior. We conducted a series of kinetic and equilibrium batch soil sorption experiments and saturated column transport studies under steady-state and transient conditions. NTO adsorbed very weakly to the studied soils. Adsorption coefficients (Kds) measured for NTO in a range of soils in batch experiments were less than 1 cm³ g⁻¹. There was a highly significant negative relationship between measured NTO adsorption coefficients and soil pH (P = 0.00011). In kinetic experiments, first order transformation rate estimates ranged between 0.0004 h⁻¹ and 0.0221 h⁻¹. There was a general agreement between batch and column-determined fate and transport parameters. However, transport studies showed an increase in the NTO transformation rate as a function of time, possibly indicating microbial growth.

      Bennett, Albert, 1958- (The University of Arizona., 1984)
    • Canal side weirs for water delivery to irrigation furrows

      Eftekharzadeh, Shahriar.; Fangmeier, Delmar D. (The University of Arizona., 1985)
      The canal side weir system is a relatively new method for water distribution to irrigation furrows. The system consists of a concrete lined ditch (canal), equipped with small openings or weirs which deliver the design irrigation flow rate into individual furrows. This research aims at evaluating the proformance characteristics of this system through laboratory, field, and computer studies. A laboratory model was used to establish head discharge relationships for various weirs at different channel velocities. For sharp entranced weirs, discharge for a given head was found to be inverselly proportional to the magnitude of the channel velocity. At small heads (20-30 mm), discharge at 0.3 m/s velocity was found to be about 15% less than the corresponding discharge at zero channel velocity . For normal irrigation settings (head on the weir = 60-80 mm), the difference was about 6%. Streamline entranced weirs were found to have negligible sensitivity to changes in the channel velocity. Field evaluation studies revealed better overall proformance than conventional systems. For an operating system, an application efficiency of 86% with uniformity coefficient of 0.84 at 7% deficit was calculated. The components of loss were run-off 4% and deep percolation 10%.
    • Changes in Water Quality During Recharge of Central Arizona Project Water.

      Riley, James J.; Stinson, Christian David. (The University of Arizona., 1999)
      The purpose of this investigation was to observe water quality changes of Colorado River water recharged on retired agricultural fields in Avra Valley, near Tucson, Arizona. The research site was at the Central Avra Valley Storage and Recovery Project, CAVSARP, located approximately 20 miles west of the City of Tucson. During the period of observation, CAVSARP was composed of three 20-acre pilot recharge basins. Eventually, the recharge facilities are scheduled to be expanded to accept 60,000 acre-feet of Colorado River water annually. Water was transported to the site via a pipeline from the Central Arizona Project, CAP, aqueduct. The period of this study was from November 1997, until October 1999. Water quality parameters were measured at the surface, prior to recharge, at depth in the vadose zone and at the groundwater table. The principal parameters monitored were: pH, conductivity, temperature, total dissolved solids, total organic carbon, alkalinity, barium, bromide, calcium, chloride, fluoride, magnesium, nitrate-N, potassium, sodium, sodium adsorption ratio, and sulfate. Recharge of CAP water began in November 1997. Water samples were collected for analysis from perched layers in the vadose zone and at the watertable. The changes in water quality in the vadose zone were compared with those observed in laboratory bench-scale soil columns with similar composition. Bromide, chloride, and nitrate-N were flushed from the formerly cultivated agricultural fields to the watertable causing a rapid increase and then a decrease in concentrations at the watertable. Concentrations of barium and calcium were significantly higher than either the recharged water or the pre-recharged watertable were attributed to the dissolution of minerals in the soil profile by the percolating water. Total organic carbon was delayed in its arrival at the watertable by perching layers and continued to increase in concentration at the end of the observation period. The change in the concentrations of other constituents could largely be explained by the mixing of the recharged CAP water with the natural watertable water below the recharge basin. The field observations of the changes in water quality in the vadose zone were similar to those observed in the bench-scale soil column studies. Further monitoring is required to verify the continuance of the trends observed in this study.

      Nolin, Anne Walden, 1958- (The University of Arizona., 1987)
      An airborne multispectral video system was used to collect soil spectral data over a four-square mile region in northeastern Arizona. Six multispectral video images were digitized. Using the red and blue bands of each image, an unsupervised classification was performed. Each was referenced to a digitized U.S. Soil Conservation Service map resulting in classification precisions ranging from 0-92.4 percent. Ground radiometric measurements were made to ascertain spectral separability of the soil samples. Soil color was determined to try to relate Munsell value to classification precision. Misclassification of soil map units was unrelated to soil brightness or areal extent of each soil. Rather, features such as slope, boundary complexity, and surface condition was responsible for misclassifications seen in this study. Best classification results occurred when soil mapping units were relatively homogeneous, possessed slight changes in slope, and had a regular surface with smooth and distinct boundaries.
    • Comparative Transport of Bacteriophage and Microspheres in an Aquifer Under Forced-Gradient Conditions

      Lenczewski. Melissa E.; Gerba, C. P. (The University of Arizona., 1993)
      The transport of viruses in groundwater was studied by using two bacteriophages (PRD-1 and M-1) and carboxylated latex microspheres (100 nm) under forced gradient conditions. This study was also designed to determine the effects of a change in pH of the aquifer on the transport of viruses and microspheres, and if the microspheres reflected the transport of viruses. The microspheres, bacteriophage, and chloride tracers were injected for a period of 12 hours into a fine- to medium-sand aquifer, 9 to 10 m in depth underlayed by a clay silt bed. Samples were collected 1, 2.5, 4, and 6 m distant from the injection well. After 10 days the pH of the groundwater was increased from 7.5 to 8.5 and samples collected for an additional 7 days. The results of this study indicated that a small increase in the pH of an aquifer can cause detachment of viruses and microspheres from the soil. In addition, the transport behavior of the bacteriophage was found to be different from the carboxylated microspheres.
    • Contaminant transport and mass transfer to runoff including infiltration

      Weber, Sofie Aimee.; Brusseau, Mark L.; Baumgartner, Donald J.; Wierenga, Peter J. (The University of Arizona., 1997)
      Experiments were conducted in a flume (3.0 meter long, 0.3 meter wide by 0.3 meter deep) to examine chemical loss to surface runoff. The bottom of the flume was made of a perforated steel plate, which allowed infiltration to occur during the runoff event. Three experiments were conducted. The objective of the first experiment was to introduce a calcium chloride solution as surface flow into the flume which was pre-saturated with calcium bromide. This experiment allowed the transfer of chemicals from soil to runoff to be examined. The second experiment was the reverse of the first experiment, i.e. the soil was saturated with calcium chloride and the surface flow contained calcium bromide. This experiment was done to examine chemical transport from runoff to the soil. In the last experiment, the soil was saturated with a mixture of calcium bromide, sodium benzoate, and pentafluorobenzoic acid (PFBA), and the surface flow contained calcium chloride. The sodium benzoate was chosen to examine biodegradation. The PFBA and bromide, both non-reactive tracers, have different aqueous diffusion coefficients. The results obtained for these two were compared to help determine if the mass transfer in the soil mainly is due to flow, or if diffusion contributes. With this research it has been shown that there are several factors influencing chemical loss to runoff infiltration, biodegradation, and there are also suggestions that there is transfer due to diffusion processes.
    • Deficit Irrigation of Bermudagrass and Seashore Paspalum for Golf Course Turf

      Walworth, James L.; Brown, Paul W.; Kopec, David M.; Bañuelos, Jaime; Walworth, James L. (The University of Arizona., 2010)
      We compared water deficit responses of 'Tifsport', 'Tifway 419', 'Tifgreen 328', and 'MidIron' bermudagrass (Cynodon dactylon x Cynodon transvaalensis), and 'SeaSpray', 'SeaDwarf', and 'Sea Isle 1' seashore paspalum (Paspalum vaginatum Swartz) under a linear gradient irrigation system in the desert Southwest. Target irrigation levels were 100, 80, 60, and 40% (2009) and 100, 80, 70, 60, and 40% (2010) of standard reference evapotranspiration (ETo). Actual water applied (including rainfall) was 100%, 83%, 66%, and 49% of ETo (2009) and 100%, 83%, 75%, 66%, and 49% (2010). Canopy temperatures increased, and quality and dry matter production declined with reduced irrigation. For optimum turfgrass quality, 75 to 83% ETo replacement was required; for acceptable quality turfgrass, 66 to 75% ETo replacement was needed for bermudagrass, and 75 to 80% ETo for seashore paspalum. Spring green-up was delayed by drought. Bermudagrasses, particularly 'MidIron', performed better than seashore paspalums under water stress conditions.
    • Design of hydrogeological networks for quantitative assessment of ground water resources

      Yitayew, Muluneh; Matlock, William G. (The University of Arizona., 1977)
      Various parameters needed for quantitative assessment of ground water resources and the methods of acquiring these parameters were considered in this study. Based on applicability and cost, the aquifer test method for acquiring parameters was selected as the basis for designing networks. Precipitation gauging stations, streamflow gauging stations, evaporation gauging stations, and observation well networks are designed for Aleydegi Plain, Ethiopia, as a test for the design. The design requires establishment of five precipitation gauging stations, 15 streamflow gauging stations, two evaporation gauging stations, and more than 100 observation wells. Instruments needed for each network are selected based on cost and availability. The capital cost of establishing these networks for assessing the ground water resources is estimated to give an idea of the capital requirements for assessment of ground water resources.
    • Detection of enteric viruses in treated wastewater sludge using cell culture and molecular methods

      Sabalos, Constantine Marc.; Gerba, Charles P. (The University of Arizona., 1998)
      Two continuous cell lines, BGM and CaCo-2 were compared for the detection of viruses in mesophilic treated sludge (MIS) and secondary disinfected wastewater effluent (WWE) samples. Samples were inoculated in both cell lines and examined microscopically for cytopathogenic effect (CPE) for 14 days. Enumeration by the most probable number (MPN) method and statistical analysis revealed significantly greater MPN values for CaCo-2 than in BGM cells for WWE. Statistical analysis of MTS and WWE samples showed that CaCo-2 cells were more sensitive than BGM (p=0.0287). This suggests that CaCo-2 cells are more sensitive for the detection of enteroviruses in environmental samples. M-PCR was developed to detect and differentiate human adenovirus (Ad) from enteric adenovirus (Ead) from seeded environmental samples. Two sets of primers hexAA1885/1913 and K402/403 (308 bp and 152 bp amplicons respectively) were chosen for combination in M-PCR. The optimum MgC12 concentration was 1.25 mM with primer concentration of 100 pmol for hexAA1885/1913 and 50 pmol for K4021403 primers. Optimum primer annealing temperature was 60° C. Sensitivity of M-PCR was 10^2 TC1D50 for Ead and Ad mixed and 10^0 TCID50 for individual viruses per reaction. M-PCR has potential in the rapid and specific identification of these types of viruses in environmental samples.