Category: Statewide

In the mass production of livestock, veterinary antibiotics are extensively used for disease control and growth promotion. One of the major users of veterinary antibiotics is the swine industry. Recent studies have shown that wastewater lagoon samples and ground water samples collected near waste lagoons contained antibiotics at concentrations that may have potential impact on humans and aquatic life. At this time, not much is known about the persistency and accumulative potential of these antibiotics in waste lagoons and in the environment. The objective of this study is to investigate the fate of two commonly used antibiotics, tetracycline and sulfamethazine, in manure lagoons. Batch experiments simulating manure lagoon conditions will be conducted to investigate the sorption of antibiotics onto sludge and the anaerobic biodegradation of antibiotics. The impact of various conditions such as pH, dissolved salts and ammonia concentrations on sorption and degradation will be studied. A direct benefit of the proposed research is an understanding of the fate of veterinary antibiotics in manure management facilities and their impact on surface and ground water.

Sediment fingerprinting via stable isotopes relies upon the premise that the physical and chemical properties of sediment will reflect its provenance. Sediments from different sources in most cases have different organic content (and in some cases different mineralogy) and as a result may exhibit different degree of impact in the receiving waters. The hypothesis in this exploratory research is that stable carbon and nitrogen isotope compositions coupled with measurements of carbon/nitrogen (C/N) ratios can be used to distinguish and quantify sources of sediments when all the factors affecting isotope spatial and temporal variability are considered. The sediment isotope fingerprinting method can be implemented successfully only if two conditions are met:(1) variation between sources must be greater than the variation within, and (2) any modification of the fingerprint due to anthropogenic and in-stream biogenic processes must be accounted for. The objectives of this research are to: (1) distinguish sediment sources by using isotopic ratios of 13C/12C or 15N/14N and atomic ratios of C/N in the Lower Cedar River Watershed; (2) evaluate the spatial and seasonal changes in the sources of sediments; and (3) explore the nature of the chemical and hydrological controls on the sources and composition of sediments.

Movement of water and nutrients though subsurface drainage systems is a concern in many Midwestern agricultural watersheds, including the Des Moines Lobe of Iowa. Although subsurface drainage has its benefits–it improves the productivity of croplands and generally reduces surface water runoff–these systems result in a greater volume of subsurface drainage flow to downstream water bodies, thereby increasing nutrient flow, specifically nitrate-nitrogen, to the same. The increased attention to subsurface drainage systems points to a need to evaluate our ability to model drainage outflow in Iowa. In 1988, a research site in Gilmore City, Iowa was established for studying subsurface drainage from agricultural land. As a result of this study there is a wealth of subsurface flow data to use in calibration and validation of models that simulate subsurface drain flow. The objectives of this investigation are: (1) to evaluate the ability of models to simulate water flow through subsurface drainage systems and (2) to evaluate differences in soil hydraulic properties for the different drainage area plots used for simulation and the impact of varying levels of site-specific soil hydraulic property information on simulated subsurface drainage. The modeling associated with this project will allow for evaluation of drainage systems using a long-term data set (1988-present) in a geographic area of importance (the Des Moines Lobe) in subsurface drainage and nitrate-nitrogen leaching. This research will provide information about factors that need to be considered in modeling subsurface drainage in Iowa, including sensitivity to soil hydraulic properties. Understanding how models perform in simulating drainage flow in an area with significant subsurface drainage and the impact of varying conditions on drainage, would be useful from a research perspective; it would also be useful to practitioners for estimating the outflow from existing systems, designing drainage-system modifications, and predicting the impact of the modifications.

Vegetative filters are a best management practice used for the removal of sediment and other pollutants from overland flow from agricultural watersheds. Although there has been a significant number of vegetative filters installed in Iowa, there is little information about the in-field water quality performance of these systems. The overall vision and goals for this project are to assess current vegetative filters in the state of Iowa to evaluate their effectiveness and educate interested stakeholders on the performance of vegetative filters. This data would be used to analyze the performance of the vegetative filters and investigate whether filter performance can be enhanced through design modifications. Based on this, the objectives of the project, this project will (1) develop educational and assessment tools for evaluating the performance of vegetative filters, (2) identify sites for assessment, (3) educate junior high and high school students on vegetative filter performance and surface water runoff issues related to water quality and biodiversity, and (4) assess the performance of vegetative filters within Iowa using site assessment tools developed and students educated through the project. This project will assist in promoting research, information transfer, and education on water resources and water quality issues in Iowa along with improving the understanding of the processes and impacts of nutrients from agriculture on water quality and the role of sediment on health of lakes and streams.

Many questions related to the impact of current phosphorus (P) management practices on P-related water quality problems are being asked by the public, government agencies in charge of nutrient regulations, producers, and researchers. Because of inappropriate P fertilizer or manure management or the need to dispose of manure, excess P often is delivered from agricultural fields to water resources. For example, the Iowa Department of Natural Resources (IDNR) has established that most Iowa lakes are seriously impaired by elevated P concentrations (Olson and Van Gorp, 2003). The Environmental Protection Agency (EPA) is developing new regulations concerning P levels in lakes and streams. The National Resources Conservation Service (NRCS) and state agencies (such as IDNR) have developed or are developing guidelines for fertilizer and manure management based on P, in addition to existing guidelines based on nitrogen (N). These guidelines are based on P risk assessment tools, often referred to as P indexes. The P index considers a variety of factors that influence P loss from agricultural fields. Although a P index has been developed for Iowa and many other states, the gaps and insufficient information of some processes have created a great deal of uncertainty in some P index components. Two co-investigators of this proposal (Mallarino and Baker) were prominent members of the team that developed the Iowa P index (Iowa NRCS, 2001; Mallarino et al., 2002b).

Excessive addition of nutrients to Iowa surface waters from nonpoint and point sources impairs our waters for beneficial uses, and it also affects down-stream users. Gulf Hypoxia, eutrophication, harmful algal blooms, and impairment of aquatic life are just some of the problems related to runoff of nutrients and sediments into Iowa waterways. To date, we do not have cost-effective ways to monitor all of the States waters and to develop Total Maximum Daily Loads (TMDLs). Also, we do not make effective use of modern sensing and computer technologies to improve our environmental cyberinfrastructure. Recent improvements in such technologies, data mining, and genetic algorithms allow radical improvements in our abilities for real-time sensing of the environment, analysis of the problems, and for evaluation of Best Management Practices or other policy decisions involved with water quality management plans under the TMDL process. The objective of this research is to gain experience with environmental cyberinfrastructure for sensing, modeling, and analyzing nutrient and sediment problems. We will purchase an initial backbone of sensors, data nodes, and access nodes for real-time measurement of gage height, velocity, dissolved oxygen, temperature, conductivity, salinity, pH, turbidity, nitrite, and nitrate. Data will be accessed, stored, and used as input for exercising water quality models (QUAL-2EU and HSPF) in a real-time environment.

Non-point source pollution due to agricultural activities is a vital issue for the State of Iowa. This project will provide a first assessment of the overall impact of a large scale conservation policy that includes several practices simultaneously on the in-stream water quality for all major Iowa rivers outlets. This project will consider the sensitivity of the water quality improvements and costs of the policy under several alternative scenarios, thus evaluating cost-efficiency of alternative conservation plans. Sediment, nitrogen and phosphorus reductions will be estimated. The results from the proposed research project will provide critically valuable information to support effective, science-based water quality management in the state of Iowa. Micro-unit-based economic models and data on land use and conservation practices are combined with a watershed-based hydrological model, the Soil and Water Assessment Tool (SWAT), to estimate the costs of obtaining water quality changes from the hypothetical placement of several broad-based sets of conservation practices. The practices analyzed in the assessment include terraces, grassed waterways, contouring, conservation tillage, land set-aside, and nutrient management strategies. The analysis is carried on 35 watersheds corresponding to the United States Geological Survey 8-digit Hydrologic Cataloging Units that are largely contained in the state. The watersheds correspond to 13 outlets, at which the in-stream water quality is measured. For the cost analysis we consider placing the identified set of practices all across the state. The major objective of the research is to estimate the costs of implementing alternative sets of identified conservation practices together with the reductions in sediment loadings, nitrogen, and phosphorus at the 13 outlets.

Animal production systems are becoming larger, and the public is concerned about the impacts of large animal facilities on water quality. Of particular concern are losses of nitrogen (N) in the forms of NH4-N, NO3-N, phosphorus (P) as PO4-P, pathogens, and antibiotics with surface runoff and subsurface drainage water. The proposed study deals with assessing the effect of land application of swine manure on NO3-N, PO4-P, bacteria, and antibiotic losses in surface runoff and subsurface drainage water. In 2000, with funding from the Leopold Center, a six-year (20002006) field study was initiated at the Iowa State University Northeast Research Center near Nashua to investigate the impact of land application of swine manure on water quality. The specific objectives of this study are: i) to determine the impact of recommended rates of swine manure, based on N and P uptake requirements of crops, on water quality; ii) to study long-term effects of over-application of swine manure on NO3-N, PO4-P, and bacteria leaching to shallow groundwater; and iii) to study the effects of spring and fall injection methods of swine manure on crop yields and NO3-N, PO4-P, and bacteria concentrations in surface runoff and shallow groundwater. From 2000 to 2003, we did not monitor the concentration of antibiotics in surface runoff and subsurface drain water. In 2004, a renewal grant proposal was submitted to the Leopold Center to continue this study for three more years as we needed to collect six years of water quality data for corn-soybean production system. In this renewal grant we proposed that we should collect data on antibiotics in the surface runoff and subsurface drainage water. The Leopold Center decided not to fund this project as the Leopold Center priorities changed to other areas. This was the first time since 1988 that the water quality research project for the Nashua site was not funded by the Leopold Center. Therefore, we requested the National Manure Management Center (NMMC) at North Carolina State University to fund this proposal and include the monitoring of antibiotics in surface and subsurface drainage water in addition to N, P, and bacteria. The NMMC funded this project for 18 months until December 2005 to analyze drainage water samples for antibiotics in objective (ii) in addition to NO3-N, PO4-P, and bacteria. The NMMC was funded with a USDA grant and this USDA grant will end on Dec. 31, 2005, thus, closing the NMMC permanently. With this proposal, we are requesting the ISWRRI to fund this project for the remaining 18 months (January 2006 to June 2007) so that this ongoing study can be completed and final conclusions of various treatments can be drawn to benefit the producers. This study site has 36 one-acre plots, with complete surface and subsurface drain monitoring system (Kanwar et al, 1999). The state-of-the-art surface runoff water and tile water monitoring facilities were installed at this site in 1988 on each of these 36 plots for sampling tile water for various water quality parameters. In 2000, nutrient management treatments were established on these plots (Table 1). These treatments include the application of swine manure to meet N and P uptake needs of corn and soybeans. Also, a new treatment was introduced in this study to apply swine manure at double the P uptake needs of corn to determine the effect of excessive application of swine manure on water quality. In addition to rate effects, manure was applied in the spring and fall to study the effect of timing of manure application on N and P leaching. Surface and subsurface drain water samples are analyzed on a weekly basis for various water quality parameters when tile drains are flowing. Five years of water quality data have been collected and we need one more years data to make final conclusions of this study. Therefore, funding from the ISWRRI for the next 18 months would be critical to the success of this project. At present, we do not have any other source of funds to complete this study.

Concern about the impact of ethanol production on Iowas water resources has increased due to the large increase in statewide ethanol production. Water use at ethanol plants could soon reach 22 billion gallons per year (Ggal/yr). Groundwater is preferred for these operations because of its high quality and stable quantity; however, placement of ethanol plants is determined by access to corn, not necessarily to groundwater supply. Permits for ethanol-related groundwater withdrawals are being granted in rural areas where determination of local pumping impact is often performed by a well driller or consultant. Tools for assessing the larger-scale impacts of ethanol production in aquifers (including water quality and ecological impacts) and for evaluating the sustainability of aquifers in the State need to be developed in order to provide a scientific basis to strengthen administrative oversight of groundwater use. The proposed research will compare the ability of three different types of groundwater models to assess the potential impact of ethanol production and determine aquifer sustainability using a test case of the Ames aquifer a regional, alluvial/buried valley aquifer in central Iowa. The grant will help fund Phase III of the project Water Supply for Ames in the 21st Century: A Comprehensive Reassessment of the Ames Aquifer and will address the following objectives: 1. Simulate steady-state and transient groundwater flow in the Ames aquifer under non-pumping and pumping conditions using a 3-D, finite-difference, groundwater flow model; 2. Compare output of 2-D and 3-D groundwater models to determine which would best identify impacts of ethanol production in aquifers and the appropriate scale of investigation; 3. Apply simulation-optimization modeling to the calibrated 3-D model to investigate the impact of large-scale ethanol development on drawdown, optimize well pumping schedules, manage future well field expansion, and assess the long-term sustainability of the aquifer. Modeling will take advantage of three USGS stream gages in Squaw Creek and the Skunk River, 65 hydraulic head targets, and nearly 100 boring logs in the Ames aquifer that have been used to construct a 3-D framework for the aquifer. In order to further understand the geology, the 3-D distribution of hydraulic head, and estimate recharge rates for the model, funds are requested for the installation of two new piezometer nests. Nest 1 in the Downtown Well Field would be designed specifically to estimate vertical K (Kv) and recharge (R) in the aquitard. Nest 2 in the Skunk River alluvium will specifically test the hypothesis that the Skunk River is a losing stream and can develop an unsaturated zone beneath the river. Both piezometer nests will be installed in fall 2007 and instrumented with combination pressure transducers/ dataloggers (corrected for barometric pressure) in order to gather real-time data that can be related to pumping schedules and USGS stream gaging data. Modeling with MODFLOW will begin in July 2007 and the simulation will be calibrated to hydraulic head measurements in the model domain and streamflow under pre-development conditions. Transient simulations will commence once the model is calibrated. Results of a regional 2-D, steady-state, analytic element, groundwater/surface water model (GFLOW) and a local-scale, 3-D, transient, groundwater flow model (MODFLOW), will be compared to determine which approach is best suited to evaluating the impacts of ethanol production at different scales. A simulation-optimization model (the Groundwater Management process for MODFLOW 2005) will be applied in spring 2008 to evaluate the sustainability of the Ames aquifer, taking into account limits on groundwater withdrawals, streamflow depletion under multiple uses (pumping) of the aquifer, and alternative climatic scenarios. By using models to assess the impact of ethanol production and to address sustainability for the Ames aquifer, the results of this study will provide a template to guide management and regulation of similar aquifers under pumping stresses from ethanol production in Iowa and the Midwest.

Interest in biorenewable energy is increasing due to concerns associated with continued reliance on fossil fuels. As the primary producer of crops used as feedstocks for ethanol production and other biorenewable energy sources, the Midwest in general, and Iowa in particular, is likely to incur a high percentage of the benefits and costs of the biorenewable energy initiative. Of significant potential concern is the impact of feedstock selection, management, and harvest on nutrient and sediment losses to receiving water bodies and the resulting impact on the integrity of aquatic resources. In the short term, increases in corn acreage, or large-scale conversion of Conservation Reserve Program lands to feedstock production, have the potential for significant negative impacts on water resources. In the longer term, conversion to perennial-plant based feedstocks for cellulosic feedstocks has great potential to positively impact aquatic integrity and water quality. However, in order to make a credible assessment of impacts of such change, significant knowledge gaps regarding the function of such landscape features need to be addressed. Managed riparian buffers, composed of woody and nonwoody vegetation, are being used to reduce inputs of nutrients, sediments, and chemicals to streams that commonly result from intensive agriculture. In central Iowa, previous studies conducted by the Iowa State University Agroecology Issue Team demonstrated that buffer attributes (e.g., physical structure, root uptake) reduce nutrient and sediment loading to streams. However, responses of most ecosystem components, including populations and communities of aquatic organisms, remain poorly studied. The emerging biorenewables initiative is likely to generate even greater agricultural production, particularly on lands susceptible to high runoff and soil erosion. Therefore, it is critical that we identify functional qualities (e.g., spatial distribution, length and width, vegetation composition and age) of effective riparian buffers and apply this knowledge to design and manage systems that protect aquatic ecosystems in an economically-viable manner. Animal and plant populations and communities respond to and reflect all physical, chemical, and biological attributes of their environment, including conditions affecting human health. Additionally, biological communities are sensitive to episodic events (e.g., pulses of contaminant inputs during high surface-water runoff) and rare contaminants that are undetected by periodic measurement of selected physical and chemical ecosystem attributes. Because organisms are now acknowledged to be definitive indicators of water quality, they are increasingly being used for regulatory assessments (e.g., USEPA) and are likewise essential tools for assessing riparian buffer effectiveness. In this study, invertebrate and fish community characteristics (i.e., species composition, abundance, growth) will be evaluated in three central Iowa streams with and without managed riparian buffers of different age, size, and structure (N = 40 total stream reaches). Instream habitat features (e.g., streambed substrate particle sizes, coarse particulate matter abundance, temperature, turbidity) will also be measured in riffles, pools, and runs where fish and invertebrates are sampled. Results of this study will produce quantitative measures of buffer effectiveness that will help guide future riparian management strategies in agroecosystems. In addition, this study will provide a platform for expanding the scope and scale of our investigations. Planned studies to increase mechanistic understanding of riparian buffer effects in agroecosystems include analyses of buffer effects on stream metabolism (e.g., dissolved oxygen, primary production), and nutrient- and energy-flow pathways through aquatic food webs. The proposed research will also provide a platform for investigating emerging issues across Iowa. Issues include conservation of systems influenced by production of biorenewable feedstocks (i.e., cereal grains, cellulosic materials in riparian buffers), lake and reservoir restoration activities, and biological assessment of recently reclassified headwater stream systems.