Grantee Research Project Results
2006 Progress Report: Evaluation Groundwater Chemistry in Gonzales County, Texas and Technical and Educational Assistance to Groundwater Conservation Districts in Texas
EPA Grant Number: X832228Title: Evaluation Groundwater Chemistry in Gonzales County, Texas and Technical and Educational Assistance to Groundwater Conservation Districts in Texas
Investigators: Sansom, Andrew , Uliana, Matthew
Current Investigators: Abbott, Michael
Institution: Texas State University
EPA Project Officer: Aja, Hayley
Project Period: June 1, 2005 through June 1, 2006 (Extended to February 29, 2008)
Project Period Covered by this Report: June 1, 2005 through June 1, 2006
Project Amount: $145,400
RFA: Targeted Research Grant (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research
Objective:
The following is a report of progress on the project funded by the U.S. Environmental Protection Agency (EPA). The project has two basic parts. Part 1 is the groundwater chemistry/recharge study in Gonzales County, and Part 2 is the development of technical and educational assistance to Groundwater Conservation Districts.
Part 1. Evaluation of Groundwater Chemistry in Gonzales County, Texas
The objective of this part of the project is to use historical data obtained from state agency databases and data collected in the field to develop a baseline evaluation of groundwater chemistry in Gonzales County, Texas (Figure 1). The results of this study will ultimately be used to evaluate the impact of confined animal feeding operations (CAFOs) on the shallow water-table aquifers in the county.
Figure 1. Location of Gonzales County
Part 2: Assistance for Groundwater Conservation Districts
The objective of this part of the project is to develop educational materials for Groundwater Conservation District (GCD) technical staff members related to understanding their aquifers, proper data collection and monitoring techniques, and use of the Texas Water Development Board (TWDB) Groundwater Availability Models (GAM). The project is supporting a major initiative at the Texas State University’s River Systems Institute (RSI) to develop a program of education, training, and technical assistance to the GCDs. The program relates to managing districts, monitoring water levels and water quality data, and understanding regional geology and hydrogeology.
Much of the work performed to this point has involved establishing cooperative agreements with personnel from the U.S. Geological Survey (USGS), TWDB, and a private public relations (PR) firm, and developing a team approach to serving the workshops. We have used formal and informal surveys to gather information about GCD staff needs and workshop logistics. As of the publication of this report, we have developed preliminary workshop topic outlines, and we are on track for providing the first set of workshops before the end of 2007.
A description of the work performed and general results are presented below.
Progress Summary:
Part 1. Evaluation of Groundwater Chemistry in Gonzales County, Texas
Existing and historical data for the study area were obtained from public sources and state agency databases. These data include:
- GIS coverage of the geopolitical boundaries, hydrologic units, geology, and hydrogeology of the study area.
- Data on well locations, well construction details, and well owners from the state-maintained databases.
- Historical data on water levels in wells.
- Historical data on water chemistry from wells throughout the study area.
The GIS data and coverages were used to construct a base GIS of the study area. This GIS includes major and minor aquifer locations (Figure 2), regional geologic outcrop patterns and structures (Figure 3), and locations of wells with groundwater chemistry and water level data (Figure 4). The GIS will be used to analyze spatial relationships in water level and water chemistry data that will address the main research question dealing with the impacts of CAFOs on water-table aquifers.
Figure 2. Map of Major and Minor Aquifers in the Study Area
Figure 3. Geology Map of Study Area
Figure 4. Map of Study Area Showing Locations of Water Wells With Water Chemistry and Water Level Data
Databases of historical water level and water chemistry data were constructed using Microsoft Excel and the AquaChem geochemistry database program. Historical water level data exist for 180 wells, including over 1,300 measurements taken between 1901 and 2006. Wells with multiple measurements through time in the Queen City and Sparta formations were identified, and hydrographs of water level trends were generated (Figure 5). These initial graphs indicate that most wells do not exhibit serious declining trends, although the data are not complete, and a more detailed analysis of the remaining data is needed.
Figure 5. Hydrographs for Select Wells in the Queen City and Sparta Formations Historical water chemistry data were obtained from 219 wells in the study area, including 470 balanced sampling events with complete analyses for major cations and anions. Most sampling records (255) are from the Carrizo-Wilcox aquifer, 69 records are from the Queen City aquifer, and 43 records are from the Sparta aquifer.
The AquaChem database was used to analyze the distribution of major cations and anions in the study area, focusing on the Queen City and Sparta aquifer systems. Waters in the Queen City aquifer system tend to be Ca-HCO3 – Na-HCO3 waters with some Ca-SO4 samples (Figure 6). Sparta aquifer samples have similar cations distributions with higher concentrations of chloride (Figure 6) and typically higher total dissolved solids (TDS). A map showing stiff diagrams for samples in the Queen City and Sparta aquifer systems (Figure 7) indicate considerable spatial variability in the major ion chemistry of the samples. Samples tend to have higher TDS in the downdip portions of the aquifers as expected. In the outcrop portions of the aquifers, there is variation in the TDS as well as the ion distributions, suggesting that impacts from surface sources of contamination are possible. Nitrate concentrations in the Queen City and Sparta aquifer systems are variable, with concentrations ranging from undetectable to almost 70 mg/L (Figure 8). A plot of nitrate versus depth (Figure 9) indicates no clear trends in either the Queen City or the Sparta aquifer systems. Further analysis of the existing data is in progress.
Figure 6. Piper Plot Showing Comparison of Queen City Water Samples Versus Sparta Sand Water Samples
Figure 7. Stiff Diagrams for Samples From the Queen City and Sparta Aquifer Systems
Figure 8. Graph of NO3 Versus Cl for All Samples Except Those From the Carrizo-Wilcox Formation
Figure 9. Graph of NO3 Versus Depth for All Samples Except Those From the Carrizo-Wilcox Formation
Personnel at the Gonzales County GCD have been contacted and have agreed to collaborate on collecting samples from wells in the outcrop zone of the Queen City and Sparta aquifer systems. Samples will be collected and analyzed for major cations and anions, as well as trace elements and some stable isotopes, and these results will be added to the historical database. Coverages showing the locations of existing CAFOs will be added to the GIS and used to investigate the relationships between the feeding operations and the chemistry of the shallow groundwater.
Part 2: Assistance for GCDs
In April 2006, Dr. Uliana prepared and delivered a presentation related to aquifer testing at the Groundwater Management in Texas: A Continuing Challenge in a Changing Environment Workshop in San Antonio (Uliana, 2006a). This workshop was primarily intended for board members and staff of GCDs, though it was attended by a broad audience. The purpose of the workshop was to provide attendees with a fundamental understanding of groundwater issues as they relate to: (1) the comprehensive management of water resources; (2) information on the current tools and technology available for groundwater management; and (3) general guidelines for development and implementation of groundwater management plans that meet new state requirements. The workshop was an opportunity to network with GCD staff and get a general idea of their opinions concerning a program of education and assistance. Attendance at the Groundwater Management in TexasWorkshop exceeded initial expectations. Feedback from workshop participants indicated that it was a success and that those in attendance benefited from the experience. The success of the workshop and interactions with GCD staff at the workshop suggest that there is a need and desire for these workshops and that developing a program of training workshops is a worthwhile endeavor.
In late 2005 and spring 2006, Dr. Uliana worked with RSI staff and Dr. Sally Caldwell (Department of Sociology, Texas State University) to develop and conduct a formal written survey for GCD board members and staff. This survey involved collection of basic data about the districts (e.g., number of staff, budgets for training, etc.), as well as data on their needs concerning training and technical assistance. This survey was finalized during the spring of 2006 and was issued over the summer. In addition to the paper survey, Dr. Uliana also conducted a less formal telephone survey of GCD staff in selected districts in order to develop a more detailed picture of their needs and perceptions. Results of each have been returned and tabulated, and I presented the results at a public conference in Austin (Uliana, 2006b). In fall 2006, Dr. Uliana also attended a meeting of the Texas Alliance of Groundwater Districts (TAGD) with RSI personnel and assisted in presenting the survey results to GCD staff and board members.
In 2006, the project team met with members of the USGS and TWDB to discuss collaborations related to training and technical assistance for GCD staff. We decided to provide the workshops to groups of districts based on the Groundwater Management Areas (GMAs), and we have developed agreements concerning which workshop topics will be offered. Dr. Uliana will provide a workshop on the basic hydrogeology of the aquifers within each GMA, the USGS staff will provide a workshop on data collection methods and techniques, and the TWDB will provide a workshop on the GAMs. We also developed an agreement with a private consulting firm (LR Public Relations) to have them offer a workshop on communicating with the public. At this time, we have developed the basic topics for the workshops and are in the process of scheduling dates and choosing venues for the actual presentations. We anticipate offering the workshops by November of 2007.
Future Activities:
Samples in Gonzales County will be collected and analyzed for major cations and anions, as well as trace elements and some stable isotopes, and these results will be added to the historical database. Coverages showing the locations of existing CAFOs will be added to the GIS and used to investigate the relationships between the feeding operations and the chemistry of the shallow groundwater.
Dr. Uliana will provide a workshop on the basic hydrogeology of the aquifers within each GMA, the USGS staff will provide a workshop on data collection methods and techniques. At this time, we have developed the basic topics for the workshops and are in the process of scheduling dates and choosing venues for the actual presentations. The team anticipates offering the workshops by November 2007.
References:
Uliana MM. How well do you know your aquifer? Aquifer testing and interpretation. Presented at the Ground Water Management in Texas: A Continuing Challenge in a Changing Environment workshop, NGWA 2006 Ground Water Summit, San Antonio, TX, April 27, 2006a.
Uliana MM. Results of the River Systems Institute’s survey of Groundwater Conservation Districts. Presented at the Charting the Course Conference (hosted by the River Systems Institute), Austin, TX, November 16, 2006b.
Journal Articles:
No journal articles submitted with this report: View all 2 publications for this projectSupplemental Keywords:
water, watershed, groundwater, surface water, water quality, concentrated animal feeding operation, CAFO, Texas (TX), hydrology, well, aquifer, MODFLOW, geographic information system, ArcView, EPA, USGS, groundwater conservation district, coliform bacteria, indicators, ecosystem monitoring, ecosystem response, ecosystem stress, Ecosystem Protection/Environmental Exposure & Risk, Geographic Area, Scientific Discipline, RFA, Ecological Risk Assessment, Monitoring/Modeling, Environmental Monitoring, State, groundwater monitoring, water supply, GIS, Texas (TX), agricultural runoff, model-based analysis, groundwater availability model, water quality model,, RFA, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, State, Monitoring/Modeling, Environmental Monitoring, Ecological Risk Assessment, agricultural runoff, model-based analysis, concentrated animal feediing operations, groundwater availability model, groundwater monitoring, water supply, Texas (TX), GISRelevant Websites:
http://www.rivers.txstate.edu Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.