According to the USEPA National Section 303(d) List Fact Sheet, bacterial pathogens are the leading cause of water quality impairments in Texas. The automated Spatially Explicit Load Enrichment Calculation Tool (SELECT) uses spatially variable factors such as land use, soil condition, and distance to streams to characterize pathogen sources across a watershed. The results support development of Total Maximum Daily Loads (TMDLs) where bacterial contamination is of concern. SELECT calculates potential E. coli loads by distributing the contributing source populations across suitable habitats, applying a fecal production rate, and then aggregating the potential load to the subwatersheds. SELECT provides a Graphical User Interface (GUI), developed in Visual Basic for Applications (VBA) within ArcGIS 9.X, where project parameters can be adjusted for various pollutant loading scenarios. A new approach for characterizing E. coli loads resulting from on-site wastewater treatment systems (OWTSs) was incorporated into the SELECT methodology. The pollutant connectivity factor (PCF) module was created to identify areas potentially contributing E. coli loads to waterbodies during runoff events by weighting the influence of potential loading, runoff potential, and travel distance. Simulation results indicate livestock and wildlife are potentially contributing large amounts of E. coli in the Lake Granbury Watershed in areas where these contributing sources are not currently monitored for E. coli. The bacterial water quality violations near Lake Granbury are most likely the result of malfunctioning OWTSs and pet waste in the runoff. The automated SELECT was verified by characterizing the potential E. coli loading in the Plum Creek Watershed and comparing to results from a prior study (Teague, 2007). The E. coli potential load for the watershed was lower than the previous study due to major differences in assumptions. Comparing the average ranked PCF estimated by physical properties of the watershed with the statistical clustering of watershed characteristics provided similar groupings. SELECT supports the need to evaluate each contributing source separately to effectively allocate site specific best management practices (BMPs). This approach can be used as a screening step for determining areas where detailed investigation is merited. SELECT in conjunction with PCF and clustering analysis can assist decision makers develop Watershed Protection Plans (WPPs) and determine TMDLs.

Training activities on the Fort Hood Military Installation have imposed serious impacts to its grass-dominated landscape. Six decades of tracked vehicle impacts have caused soil compaction and vegetation reduction which has lead to severe surface erosion. This investigation examined two conservation practices directed at improving and creating sustainable training conditions on Fort Hood training lands, contour ripping and the application of composted dairy manure. The application of composted dairy manure may increase vegetation, while contour ripping may decrease discharge, both of which will lead to a decrease in erosion. Three small 0.30 ha watersheds were established on Fort Hood in January 2005. Each watershed had 0.46 m berms installed on all four sides with a 0.305 m H-flume and was equipped with automated storm sampling equipment. Soil samples were collected prior to any treatments, and twice after compost applications. Discharge and precipitation was collected continuously on each watershed. Stormwater samples were collected during storm events and analyzed for water quality parameters. Water quality samples, discharge and precipitation records were collected between January 2005 and July 2007. Three composted dairy manure application rates at 0, 28 and 57 m3 ha-1 were applied on watersheds C0, C1 and C2, respectively; watersheds were evaluated for effects on NO3 and soluble reactive phosphates (SRP) concentrations and loadings in storm events and on stormwater discharge. Twenty two months after the initial compost application, the two previously composted watersheds (C1 and C2) were treated with contour ripping and C2 received a second compost application. The compost application caused the spikes in NO3 and SRP concentrations and loads immediately after application. Both NO3 and SRP concentrations decreased as the number of days from application increased. Compost application did not appear to have an effect on the discharge from watersheds. Contour ripping had a significant effect on stormwater discharge. Contour ripping decreased discharge by 74 and 80% on C1 and C2, respectively when compared to the untreated control (C0).

Essential to human life is water. Drinking water, in particular, is of utmost significance for all living creatures including man. An examination of the transmission process of drinking water reveals the high importance of pipe lines. The water pipe lines delivering water today encounter serious problems. Corrosion has caused deterioration in pipe lines, which contributes rust to drinking, a serious water quality problem. In addition, pipe line failures have caused social issues, such as suspension of water supply. This study developed a model to estimate the life expectancy and residual life of a pipe based on the assessment of failure risk in order to evaluate the current failure possibility and predict when the pipe will reach the point of failure. The developed model for estimation of residual life by failure risk was used to assess the failure risk of water pipes based on the general data and pipe sources of the Chang Won City water pipes. The efforts to diagnose and evaluate water pipes are limited to the assessment of current pipe conditions, which is why they can easily determine the priority of rehabilitation based on the current pipe conditions but have hard time getting information about how the pipes have deteriorated to the point of requiring rehabilitation. The objectives of this study are: (1) develop a model for estimating corrosion rates and residual thickness of water pipes, (2) assess loads and stress affecting water pipes, (3) to estimate damage risk, and (4) calculate safety factors. Results of the study could help reduce rehabilitation costs and secure water quality after renovation. Thus it would contribute to the safe and stable operation and management of pipe networks by increasing the life of water pipes.

Abstract The Love River basin is the most important river watershed in Kaohsiung City, Taiwan. It is 16-km long, drains a catchment of more than 50 km2. Figure 1 shows the Love River, its catchment, the sewer system and the manmade water ways for collecting the municipal wastewater from households (D,H,K,Bao-zhu,No.2). The pump stations were settled to pump the domestic waste water to the sewer system . The 16-km river begins as a trickle of runoff in the mountains of Kaoshiung County before flowing through the city and finally emptying into the Taiwan Strait. The drainage area is 5,600 hectares, and the population in the area is around 720,000. Investigation results demonstrate that the main water pollution sources are municipal wastewater, industrial wastewater, non-point source (NPS) pollutants, agricultural wastewater, and livestock wastewater. Investigation results show that the municipal wastewaters contribute more than 90% of the overall pollution loads to Love River, respectively. Currently, the percent of sewer system connection in the Love River watershed is less than 50%. Part of the municipal wastewater is discharged into the river without treatment. Moreover, there are 55 registered industrial factories discharge their wastewater into the Love River. Illegal or expedient discharges are sometimes practiced feeding polluted industrial flows into the river. Therefore, the untreated municipal wastewaters is the major cause of the poor water quality. The major objectives of this study were using the calibrated WASP water quality model (1) to obtain to evaluate the carrying capacity calculations for BOD . (2)to assess the improved effect to water quality by dilution of the river source water (3) to assess the improved effect to water quality by settling the local waste disposal beside the pumping station(4) to evaluate the improved effect to water quality by construction of riverbank natural treatment systems, and (5) to evaluate the improved effect to water quality by raising the popularity rate of hygienic sewers piping for users . Results from this study will provide the predicted remedial effects before bringing all sorts of costly remedial constructions into practice. Due to the construction of the sewer system was time-cosuming and expensively, and if the water quality of Love River was expected to be improved in the short-term , the comprehensive strategies for Love River watershed management could been proposed . Key Words Water quality; watershed; carrying capacity; BOD

Research was conducted to compare the effects of composted dairy manure and raw dairy manure alone, or in combination with supplemental inorganic fertilizer, on soil chemical properties and Coastal bermudagrass [Cynodon dactylon (L.) Pers.] yield and nutritive value. Composted dairy manure was surface applied at rates of 14 (125 kg N ha-1), 29 (250 kg N ha-1) and 57 (500 kg N ha-1) Mg dry matter (DM) ha-1, and raw dairy manure was surface applied at a rate of 54 (420 kg N ha-1) Mg DM ha-1 to established bermudagrass. Selected compost and manure plots received supplemental inorganic N at rates of 56, 84 and 112 kg ha-1 cutting-1 or 112 kg ha-1 cutting-1 of supplemental N with supplemental inorganic phosphorus or potassium at rates of 112 kg P2O5 ha-1 yr-1 and 112 kg K2O ha-1 cutting-1, respectively. Composted dairy manure (29 and 57 Mg DM ha-1) or raw manure alone increased cumulative forage yields compared to the untreated check in both years of the study, but were less than those obtained using only inorganic fertilizer. Application of 56 kg N ha-1 cutting-1 or more of supplemental N to compost (29 and 57 Mg DM ha-1) or iv manure produced forage yields that were equal to or greater than those obtained using inorganic fertilizer alone. However, increasing compost rate did not increase tissue N concentrations regardless of supplemental inorganic N rate. Yield and tissue K concentrations were increased in the second growing season when supplemental inorganic K was applied to 29 Mg ha-1 of compost or 54 Mg ha-1 of raw dairy manure. No yield response was observed when supplemental inorganic P was applied to compost or manure. Soil pH and concentrations of NH4, NO3, K, Ca, Mg and Mn were increased by application of compost or manure. Soil P concentrations in the 0 to 5-cm zone exceeded 200 mg kg-1 when compost was applied at the high rate. Dairy manure compost was an effective nutrient source for bermudagrass hay production, but will require the use of supplemental N and, in some cases, K to achieve yields comparable to inorganic fertilizer.

Most of the pollution found in highway runoff is both directly and indirectly contributed by vehicles such as cars and trucks. The constituents that contribute the majority of the pollution, such as metals, chemical oxygen demand, oil and grease, are generally deposited on the highways. These can become very harmful and detrimental to human health when they come in contact with our water system. The connecting tie between these harmful highway-made pollution and our water system, which includes our ground waters and surface waters, is rainfall. The main objective of this runoff study was to characterize and assess the quantity and quality of the storm water runoff of a bridge deck that discharged into a receiving water body. The bridge deck and the creek were located in the coastal margin region in the southeast area of Texas on the border of Harris and Galveston counties. Flow-activated water samplers and flow-measuring devices were installed to quantitatively determine the rate of flow of the bridge deck and determine different pollutant loading by sampling the receiving water body (Clear Creek). The collected samples were analyzed for total suspended solids, toxic metals, and other relevant constituents of concerns. The results illustrated that the runoff from the bridge deck exhibited low total suspended solids concentrations (which were highest in the creek). However, other metal constituents like the zinc and cooper concentration were high and above standards. The phosphate concentrations in the creek were the highest and exceeded EPA standards. Several nitrate concentrations were also noticeably above EPA standards.

Effect of Alkalinity in Irrigation Water on Selected Greenhouse Crops. (August 2004) Luis Alonso Valdez Aguilar, B.S., Universidad Aut??noma de Nuevo Le??n, Mexico; M.S., Universidad Aut??noma Chapingo, Mexico Chair of Advisory Committee: Dr. David Wm. Reed Bicarbonate (HCO3-) and carbonate (CO32-) are the most important ions that determine alkalinity. When the carbonates accumulate in a growing medium, the growing medium solution pH reaches levels that cause plant growth inhibition, which is caused primarily by the transformation of soluble forms of Fe into insoluble forms. The general objective of this research was to provide information about the limits of tolerance to alkalinity in ornamental plants, and to study the interaction of ions such as ammonium (NH4+) and nitrate (NO3-) on the response of plants to alkalinity, as well as the effect of the counter-ions potassium (K+), sodium (Na+), cesium (Cs+), ammonium (NH4+) and rubidium (Rb+). The maximum SPAD index was estimated to occur at 0 mM of NaHCO3 in chrysanthemum, mini-rose, and hibiscus ??Bimini Breeze?? and ??Mango Breeze??. For vinca it was set at 2.64 mM. A 15% decrease from the maximum SPAD index was considered the threshold to declare the toxic concentration of NaHCO3, which was calculated based on the maximum SPAD index predicted by the models. The toxic concentration of NaHCO3 was set at 4.1, 1.1, 6.7, 3.1, and 6.3 mM of NaHCO3 in chrysanthemum, mini-rose, vinca, and hibiscus ??Mango Breeze?? and ??Bimini Breeze??, respectively. Hibiscus ??Bimini Breeze?? was considered tolerant to alkalinity, due to increased Fe-reduction capacity and acidification of the growing medium. In the hydroponic experiment, results showed that the NH4+:NO3- ratio altered the response of sunflower plants to alkalinity. Sunflower plants grew better in solutions containing 5 mM NaHCO3 prepared with a 0.25:0.75 NH4+:NO3- ratio. This was possible due to the reaction of NH4+ with the HCO3-, which reduced its buffering capacity. The response to HCO3--induced alkalinity was modified by the counter-cation of HCO3-. In bean plants, at low-to-intermediate levels of Na+ and HCO3- induced approximately same growth decrease. At high concentration, Na+ induced a decrease on shoot growth that exceeded the toxic effects of HCO3-. Thus, the toxic effect of Na+ is higher than that of HCO3- when its concentration is high. Rubidium was extremely toxic at concentrations of 7.5 mM.

This research focused on expanding the capabilities of the Water Rights Analysis Package (WRAP) for incorporating salinity considerations in assessments of water availability. A simulation modeling approach was used to address this issue and a generalized simulation model called WRAP-SALT was developed. The Brazos River Basin served as a case study to test the simulation approach adopted by the model. The simulation model adopts a generalized modeling approach applicable to any river basin system. The model tracks salinity throughout a river basin system over different periods of time for alternative scenarios of water use, reservoir system operating policies, and salt control mechanisms. The model was applied to the Brazos River Basin considering different management scenarios and the results obtained were analyzed. Reservoir reliabilities were assessed under user imposed salinity constraints. It was observed that the water supply reliabilities decreased significantly if salinity constraints were considered. Salt control dams proposed by the U.S. Army Corps of Engineers were also incorporated in the simulation of the river basin. It was observed that salinity in the main stem of the Brazos River was significantly reduced. However, no significant improvement was observed in water supply reliabilities.

Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2004. / Includes vita. Includes bibliographical references (leaves 67-74).

Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 131-143).