- Groundwater/Surface Water Interactions
Subtask 1: Groundwater/Surface Water Interactions Existing Data Study - The initial phase of this study will involve collating existing published data related to groundwater/surface water interactions in alluvial aquifers adjacent to the Colorado River, within Segment 1428. The UT-BEG will obtain groundwater level and water quality data from the Texas Water Development Board (TWDB) database for the length of record. Additionally, the UT-BEG will obtain surface water flows, stages, and quality from the U.S. Geological Survey (USGS) and the TCEQ.
Subtask 2: Groundwater/Surface Water Interactions Reconnaissance Study - Reconnaissance analysis will provide the most appropriate site to conduct the pilot study based on data availability and degree of linkages between the alluvial aquifer and the river. The field reconnaissance will include field visits to the proposed areas where existing wells are located, as selected from Task 5.1, identification of areas where monitoring wells may be installed, and similar field investigations that are necessary to select the appropriate sampling points to support the data objectives.
Subtask 3: Groundwater/Surface Interactions Report - The report will include tabulated records of stream flows and ground water levels over the period of record from available public records; identification of existing wells that may be able to be used as monitoring wells, information on the geologic characteristics of t he adjacent alluvium that serve as shallow ground water supply aquifers within this stream reach, and any available water quality data that is specific to the stream reach will be assembled in tabulated form. A narrative summarizing and analyzing the data collected will also be produced as a part of this report.
- Delineation of Potential Contamination Sources Study and Report
Subtask 1: Delineation of Potential Contamination Sources Report - The distribution of onsite water treatment and OSSF systems will be identified from available published sources or publicly available databases. Impacts of these systems on local groundwater will be evaluated using the existing TWDB database. Comparison of the potential sources identified with monitoring wells that may be useful for the project will allow the identification of transects for study of sources, ground water quality, and surface water quality. A report will be produced that will provide the geographic location of potential sources of contamination. These potential sources will be designated on project figures to be used in correlation with the information assembled in Objective 5. The report will include a narrative explaining the potential sources of contamination by type.
- Water Quality Monitoring Objectives
Subtask 1: Conduct a Data Review - In addition to the reviews described in Objectives 3 and 4, the UT-BEG will conduct a final data review to identify data gaps, and to determine the types of data needed to achieve the data quality objectives. The intent is that the data collected will be used to support TCEQ's process in developing Total Maximum Daily Loads (TMDLs) and therefore, the data review will focus on providing specific sample results related to the project goals and objectives of supporting TCEQ's process of TMDL development.
Subtask 2: Groundwater and River Sampling Site Identification - Groundwater sampling points will be selected based on the results of Objectives 3 and 4. Sampling points representative of ground water influenced by the river, OSSFs, or other contamination sources, such as neighborhoods served by OSSFs, will be indentified. In addition, groundwater sampling points will, if possible, be located near stream reaches where extensive databases of surface water quality are available.
Subtask 3: Data Quality Objectives (DQOs) - The UT-BEG will develop data quality objectives which will clarify the purpose of the monitoring study, define the most appropriate type of data to collect and help determine the most appropriate methods and conditions under which to collect them. The data collected will be useful for comparison to the TCEQ's methodology and model approach to developing TMDLs.
Subtask 4: Develop a Water Quality Monitoring Plan - The UT-BEG will summarize the specific objectives of the project's monitoring effort, the data requirements for data analysis and interpretation to be used in the project, and the preliminary locations, times, and other details of planned monitoring activities.
Subtask 5: QAPP Planning Meetings - The UT-BEG will schedule a QAPP planning meeting with the TCEQ Project Manager, Quality Assurance staff, technical staff, management, and contractors to implement a systematic planning process based on the elements of the TCEQ NPS QAPP Shell. The information developed during the planning meeting will be incorporated into a QAPP.
- Final Report
Subtask 1: Final Report - The UT-BEG will incorporate all comments received on the draft report to prepare a final report summarizing all project activities, findings, and the contents of all previous deliverables, referencing and/or attaching them as web links or appendices. This comprehensive report will provide analysis of all activities and deliverables under this scope of work. The report will include the following information:
- Table of Contents
- Executive Summary
- Project Significance and Background
- Project Studies and Coordination Activities
- Results and Observations