Addressing Uncertainty in TMDLS: Short Course at Arkansas Water Resources Center 2001 Annual Conference

Management of a critical natural resource like water requires information on the status of that resource. The US Environmental Protection Agency (EPA) reported in the 1998 National Water Quality Inventory that more than 291,000 miles of assessed rivers and streams and 5 million acres of lakes do not meet State water quality standards. This inventory represents a compilation of State assessments of 840,000 miles of rivers and 17.4 million acres of lakes; a 22 percent increase in river miles and 4 percent increase in lake acres over their 1996 reports. Siltation, bacteria, nutrients and metals were the leading pollutants of impaired waters, according to EPA. The sources of these pollutants were presumed to be runoff from agricultural lands and urban areas. EPA suggests that the majority of Americans-over 218 million-live within ten miles of a polluted waterbody. This seems to contradict the recent proclamations of the success of the Clean Water Act, the Nation\u27s water pollution control law. EPA also claims that, while water quality is still threatened in the US, the amount of water safe for fishing and swimming has doubled since 1972, and that the number of people served by sewage treatment plants has more than doubled

Watershed-scale agricultural land-use impact on instream physicochemical parameters

Nonpoint source (NPS) pollution is often the result of runoff losses from agricultural or urban areas. Even though the watershed approach to controlling NPS pollution is identified as the most efficient approach, data linking watershed scale land use and specific water quality implications are very limited. The objective of this study was to quantify the impact of agricultural land use on stream physico-chemical properties. The upper reach of Flint Creek was monitored at two sampling points draining an agricultural land. At each of these points, continuous measurement of stream characteristics such as temperature, dissolved oxygen (DO) concentration, depth, pH, and conductivity were taken at three different dates. Also, water samples were collected and analyzed for nitrogen (N) and phosphorus (P) concentrations to discern the impact of agricultural land use on water quality. The results indicated that nitrate N (NO3-N) and phosphate P (PO4-P) concentrations increased as the agricultural land use increased in the watershed. Fluctuation in the DO concentration also increased with higher agricultural land use. In order to help decrease the amount of nutrients introduced to the stream, a variety of best management practices (BMPs) could be implemented in the watershe

Dissolved Oxygen Monitoring in Kings River and Leatherwood Creek

The Clean Water Act (CWA) establishes the basic structure used to regulate water quality. Under the CWA, States are required to assess water bodies relative to water‐quality standards and designated beneficial uses and then to submit lists of impaired bodies every other year to the US Environmental Protection Agency (USEPA). In 2015, at least 4,800 water bodies were listed as impaired by dissolved oxygen across the US (USEPA, 2015). Aquatic species like fish and macroinvertebrates depend on adequate dissolved oxygen for survival. Low dissolved oxygen can lead to fish kills, reduced aquatic diversity, and nuisance smells from anaerobic conditions – ultimately, low dissolved oxygen concentrations result in water bodies not being able to meet the aquatic life designated use

2005 Nutrient and Sediment Monitoring Report Ballard Creek Near Arkansas/Oklahoma Line

The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas\u27 Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact recreation streams. The identified causes of the impairment were: sediment, bacteria and nutrients. In 1997, the University of Arkansas completed a project that estimated the phosphorus loading from each of the thirty-seven sub-watersheds. This project also prioritized watersheds for implementation work based on phosphorus loads, nitrogen loads and total suspended solids loads per unit area. The thirty-seven sub-watersheds were grouped into Low (16), Medium (10) and High (11) categories based on phosphorus loadings. The selection of a sub-watershed for targeted intensive voluntary BMP implementation was based on the following criteria: a) the sub-watershed had to be above the current median value for phosphorus loading, b) there would be no sewage treatment plant in the sub-watershed, and c) land user interest. The Upper Ballard Creek watershed met all these requirements. The watershed covers 6700 hectares. The creek is listed in the High category with a unit area loading of 1.75 kg. per hectare per year. The median value for the thirty-seven watersheds was 0.73 kg. per hectare per year

Measuring variability in trophic status in the Lake Waco/Bosque River Watershed

<p>Abstract</p> <p>Background</p> <p>Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal <it>in situ </it>variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI) at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment.</p> <p>Methods</p> <p>We used the passive diffusion periphytometer to measure <it>in-situ </it>nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll <it>a </it>production in the periphytometers was used as an indicator of baseline chlorophyll <it>a </it>productivity and of maximum primary productivity (MPP) in response to nutrient enrichment (nitrogen and phosphorus). We evaluated the lotic ecosystem trophic status index (LETSI) using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site.</p> <p>Results</p> <p>The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02) located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05) were the next most enriched sites. Trophic class varied for enriched sites over seasons.</p> <p>Conclusion</p> <p>Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring <it>in situ </it>responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show significant potential for use in nutrient gradient studies.</p

Effects of Aluminum Toxicity on Growth and the Complement of Polypeptides in the Root Tips of Wheat

Aluminum toxicity is the primary limiting growth factor in acid soils. Wheat . The wheat cultivar "Victory" is Al sensitive at 1 ug/ml Al, while the wheat cultivar "TAM W-101" is tolerant at 2 ug/ml Al. Aniol (4) proposed that a group of proteins present only in Al tolerance plants bind with Al to render it harmless to plant cells. This hypothesis was tested by determining if induction of specific proteins was associated with 2 ug/ml Al treatment in Victory and TAM W-101 root tips. The proteins extracted from each cultivar were quantified and analyzed by SOS-PAGE. The effect of Al on the proteins of wheat root tips was not dramatic. SDS-PAGE did not reveal the presence of any new, major proteins which might be Al-binding proteins. Two-dimensional PAGE analysis of the proteins of Victory cytoplasmic and microsomal fractions was conducted. This highly sensitive protein analytic tool revealed eight m~jor proteins in Al-treated Victory root tips that were not present in the controls, and three proteins that were present in the control and not in the Al-treated root tips.Botan

A Life Cycle Analysis of Land Use in US Pork Production

The goal of this study was to analyze land use in the production of US pork using Life Cycle Assessment (LCA). LCA is a comprehensive methodology for quantitatively analyzing potential environmental impacts associated with complex systems. Identification of processes contributing to high environmental impacts often highlights opportunities for gains in efficiency, which can increase the profitability and sustainability of US pork. The environmental impact category analyzed in this assessment was land use. After reviewing existing information regarding land use in agriculture and livestock production, analysis for US pork production was performed at two scales: cradle-to-grave and cradle-to-farm gate. The cradle-to-grave analysis provided a scan-level overview of land use associated with the production and consumption of lean pork at an aggregated national level. The cradle-to-farm gate analysis provided a more granular assessment of the land use required for live swine production, and evaluated the use of alternate ration formulation as a tool for reducing environmental impacts. [Excerpt from report]

Systems and methods for wastewater treatment

Disclosed is a system and method for treating wastewater. The system includes a bioreactor which defines a basin for receiving wastewater to be treated; a membrane module in fluid communication with the bioreactor; and a dissolution tank. The tank includes a pressure vessel that contains a portion of the wastewater to be treated and provides a regulated, pressurized gas head space above the wastewater. The tank also includes at least one liquid spray nozzle that permits passage of the wastewater into the gas head space of the pressure vessel and an outlet for discharging the wastewater having a desired gas concentration from the pressure vessel. The system also includes a pumping mechanism for supplying the wastewater to the spray nozzle of the tank such that fluid droplets are formed in the gas head space and the gas contained within the pressurized head space is dissolved into the wastewater

Sustainability Assessment of U.S. Beef Production Systems

With increasing public concern and awareness of agricultural sustainability issues, comprehensive methodologies such as life cycle assessment are required to benchmark the beef industry and identify areas of opportunity for continuous improvement. To that end, the Beef Checkoff completed a retrospective sustainability assessment benchmark in 2013 by using Eco-efficiency analysis to compare the years 2005 and 2011. At the time of the analysis, the methodology used was the most up-to-date and comprehensive – indeed the analysis remains one of the only complete cradle-to-grave assessments of the U.S. beef industry. In 2015, a further refined version of the Eco-efficiency analysis was completed to incorporate new primary data sources from the beef value chain for the years 2011-2013. As the young and dynamic field of sustainability science continues to evolve, there is a need to adapt and update the methodologies used in life cycle and broader sustainability assessments of the beef industry. Consequently, this project updated and expanded the original Eco-efficiency analysis to the SimaPro™ computational platform. The move to the SimaPro™ platform will allow for direct linkages with the Integrated Farm Systems Model (USDA-ARS), which is the simulation model that has been used to generate life cycle inventories from the feed production, cow-calf, and backgrounding/feedlot segments of the beef industry. Additionally, the SimaPro™ platform will allow for even more transparent reporting of our inventories and results to the broader life cycle assessment, sustainability science, and beef communities, which is key to advancing the field and benchmarking beef’s sustainability. Finally, this project further expanded the economic sustainability evaluation of U.S. beef industry to include the direct, indirect, and induced economic activity and value that is generated from beef production. [Excerpt from report]

A Retrospective Assessment of US Pork Productions: 1960 to 2015

The primary goal of this study is to assess the carbon, energy, water and land footprints per kg (2.2 pounds) of live weight (LW) pork produced at five-year increments between 1960 and 2015. This assessment utilizes the Life Cycle Assessment (LCA) methodology, which is a technique to assess the potential environmental impacts associated with a product system by compiling an inventory of relevant energy and material flows, evaluating the associated burdens, and interpreting the results to assist in making more informed decisions and to provide an understanding of the drivers of change over the past 55 years. This LCA is “cradle-to-farm gate” e.g. covering the material and energy flows associated with the full supply chain beginning with extraction of raw materials through the production of live, market-weight swine, inclusive of culled sows, at the farm gate. On average, production-weighted metrics declined across all four categories over the assessment period. The largest decrease was seen in land use (75.9 percent), followed by water use (25.1 percent), then global warming potential (7.7 percent), and finally energy use (7.0 percent). [Excerpt from report]