Big Cypress Creek Modeling and BST

Project Work Plan

Goals and Objectives

To provide stakeholders and agencies with sufficient information to address bacteria impairments on Big Cypress Creek and tributaries (Hart and Tankersley Creeks) between Lake O' the Pines and Lake Bob Sandlin through verification of use attainment, revision of water quality standards and/or designated uses, or development of a WPP or TMDL by 1) conducting bacterial source tracking, 2) developing a comprehensive GIS inventory and conducting a watershed source survey, and 3) analyzing data using Load Duration Curves and spatially explicit modeling.

Measures of Success

  • Decision-making for watershed planning activities, including BST, LDC analysis, and spatially explicit modeling, is founded on local stakeholder input.
  • BST, LDC analysis, and spatially explicit modeling in the study area are conducted using data of known and acceptable quality.
  • Bacteria loads are estimated for each of the three segments in the study area through the development of LDCs.

Bacteria loads are estimated from various contributing sources and critical loading areas within the watersheds are identified based on SELECT model output and BST.

Problem/ Need Statement

Big Cypress Creek (and its tributaries) are located in the Cypress Creek Basin. The headwaters of Big Cypress Creek originate in southeast Hopkins County. From there, Big Cypress Creek flows east into Lake Cypress Springs and then into Lake Bob Sandlin in Franklin County. After leaving Lake Bob Sandlin, Big Cypress Creek, which forms the county line between Titus and Camp Counties, flows southeast to Lake O' the Pines and then finally to Caddo Lake before entering Louisiana. The watershed is characterized by gently rolling wooded hills and broad, frequently flooded, densely vegetated stream bottoms. Post oak savannah is predominant in the western portion of the basin, while pineywoods are common in the eastern portion.

The Big Cypress Creek watershed, between Lake Bob Sandlin and Lake O' the Pines, encompasses approximately 445 square miles in Camp, Morris, Titus and Upshur Counties. In 1996, Big Cypress Creek (Segment 0404) was placed on the Texas 303(d) List for having bacteria levels that exceed water quality standards. In 2000, Tankersley Creek (Segment 0404B) was placed on the 303(d) List for bacteria, and in 2006, Hart Creek (Segment 0404C) was placed on the 303(d) List for bacteria. Other tributaries to Big Cypress Creek are not currently impaired for bacteria, but they are likely contributing some degree of bacteria loading to the impaired reaches of Big Cypress Creek.

The focus of this project will be on bacterial water quality issues in Segments 0404, 0404B, and 0404C. Additionally, Segment 0404 is the contributing watershed to Lake O' the Pines (Segment 0403) and is covered by One Total Maximum Daily Load for Dissolved Oxygen in Lake O' the Pines (Segment 0403). The TMDL was adopted by the TCEQ on April 12, 2006, approved by the TSSWCB on March 23, 2006 and approved by the EPA on June 7, 2006. The TMDL determined that low dissolved oxygen concentrations in the reservoir are due to high rates of photosynthesis and respiration in aquatic vegetation and that phosphorus is the limiting nutrient during the critical conditions. The TMDL determined that a 56% reduction in total phosphorus loading is needed to restore water quality. An Implementation Plan (I-Plan) was developed to reduce phosphorus loadings from the contributing watershed. Implementation strategies were identified for point source dischargers (total phosphorus effluent limits), animal feeding operations (BMPs to reduce runoff of sediment and nutrients from poultry litter application sites and dairies), forestry operations (BMPs to reduce runoff of sediment and nutrients), and other sources (on-site sewage facilities, boat sewage disposal, sites permitted for land application of domestic sewage sludge). On July 9, 2008, the TCEQ approved the I-Plan for One TMDL for Dissolved Oxygen in Lake O' the Pines. The TSSWCB approved the I-Plan on July 17, 2008. It is anticipated that many of the implementation strategies designed to reduce phosphorus loadings will also have a positive impact on reducing bacteria loadings to Big Cypress Creek.

Through the Lake O' the Pines TMDL process, watershed stakeholders have become extremely familiar with water quality rules and regulations, as well as, approaches to watershed planning. As such, local stakeholders have already expressed interest in taking an active role in addressing the bacteria impairments.

Land use in the watershed is predominantly cropland and pasture (about 48%) and forest (about 40%). During periods of rainfall, which averages approximately 46 inches annually, bacteria originating from aquatic birds and mammals, livestock, inadequately treated sewage, and/or failing septic systems may be washed into the streams and have the potential to impede recreational use of the waterbodies. Bacterial indicators, such as E. coli, may remain in the streams at levels exceeding established criteria and can be measured well after a rain event has occurred. These microorganisms are normally found in wastes of warm-blooded animals and are generally not harmful to human health, but may indicate the presence of pathogens that can cause disease.

Lake O' the Pines and other waterbodies in its watershed are extremely important to the surrounding region. Lake O' the Pines provides drinking water for 7 cities and towns, numerous rural water districts, and several steel manufacturing and electric generating companies. In addition, the City of Longview (population 70,000) will be using the lake as a drinking water source in the near future. The lake is an important resource to the timber industry and to agricultural enterprises such as the poultry industry, dairies, cow/calf operations, and for irrigation. Recreation and tourism are significant sources of income for residents of the watershed. Boating and fishing for trophy bass, catfish, and crappie lure large numbers of recreational users to the watershed each year.

The TCEQ and the TSSWCB established a joint, technical Task Force on Bacteria TMDLs in September 2006 charged with making recommendations on cost-effective and time-efficient bacteria TMDL development methodologies. The Task Force recommended the use of a three-tier approach that is designed to be scientifically credible and accountable to watershed stakeholders. The tiers move through increasingly aggressive levels of data collection and analysis in order to achieve stakeholder consensus on needed load reductions and strategies to achieve those reductions. In June 2007, the TCEQ and the TSSWCB adopted the principles and general process recommended by the Task Force and directed agency staff to incorporate the principles of the recommendations into an updated joint-agency TMDL guidance document.

Major revisions to the Texas Surface Water Quality Standards are being drafted by TCEQ, including the establishment of numeric nutrient criteria for reservoirs and modifications to contact recreation use and bacteria criteria. As part of this process, TCEQ is developing procedures for conducting recreational Use Attainability Analyses (UAAs). In order for a new category of recreational use or a different bacteria water quality standard to be applied to a waterbody, a recreational UAA will need to be conducted. TCEQ and TSSWCB have collaborated on developing a list of priority waterbodies for collecting information needed for recreational UAAs. Segments in this project's study area are on that list.

In accordance with the Memorandum of Agreement Between the TCEQ and the TSSWCB Regarding TMDLs, Implementation Plans, and Watershed Protection Plans, the TSSWCB has agreed to take the lead role in addressing the bacteria impairments in the study area. Through this and associated projects, the TSSWCB and NETMWD will work with local stakeholders to progress through the data collection and analysis components of the first two tiers of the Task Force recommended three-tier approach. The goal is to remove the waterbodies in the study area from the 303(d) List; however, the mechanism is not predetermined. At the end of this two-year assessment project, possible outcomes include: 1) waterbodies are achieving current water quality standards, 2) waterbodies are achieving revised water quality standards, based on TCEQ triennial review process, 3) adequate data exists to support a UAA to change water quality standards, 4) adequate data exists to develop a Watershed Protection Plan, or 5) adequate data exists to develop a TMDL and I-Plan for TCEQ adoption.

General Project Description

In order to communicate project goals, activities, results and accomplishments to affected parties, TWRI, SAML, and BAEN will participate in public stakeholder meetings as needed. At a minimum, public stakeholder meetings shall consist of an organizational/kick-off meeting, a source survey design meeting, a meeting presenting results from initial data analysis and the GIS inventory, a Texas Watershed Steward Program workshop, two project update meetings during the middle of the project, a meeting presenting data analysis results, and a meeting presenting final technical reports.

TWRI will develop and disseminate educational materials to watershed stakeholders, including, but not limited to, flyers, brochures, letters, and news releases. BAEN, SAML, and NETMWD, shall contribute content matter for educational materials as appropriate. TWRI will develop, host and maintain an internet webpage for the dissemination of project information. BAEN, SAML, and NETMWD, shall contribute content matter for the webpage as appropriate.

BAEN will develop a comprehensive GIS inventory for the study area, with assistance from NETMWD through TSSWCB project 09-54 Assessment of Contact Recreation Use Impairments and Watershed Planning for Big Cypress Creek and Tributaries (Hart and Tankersley Creeks).

TSSWCB, in cooperation with SSL, will provide BAEN a current land use classification, based on 2004-2006 imagery, for the study area through TSSWCB project 08-52 Classification of Current Land Use/Land Cover for Certain Watersheds Where TMDLs or WPPs Are In Development.

In order to apply knowledge gained through TSSWCB project 07-06, Fate and Transport of E. coli in Rural Texas Landscapes and Streams, BAEN will assist NETMWD in designing a watershed source survey, to be conducted through TSSWCB project 09-54, that better characterizes the possible sources of bacteria loadings in the study area. SAML will also assist NETMWD in designing the watershed source survey.

To provide sufficient water quality data to characterize bacteria loadings in the study area, NETMWD, through TSSWCB project 09-54, will conduct routine ambient monitoring, effluent monitoring, and biased-flow monitoring under high flow (storm event influenced) conditions.

TWRI will develop a Quality Assurance Project Plan (QAPP) to ensure data of known and acceptable quality are generated and used in this project. The QAPP shall be consistent with the TSSWCB Environmental Data Quality Management Plan.

To determine bacteria load reductions needed to achieve water quality standards, BAEN, with assistance from NETMWD, will conduct a Load Duration Curve (LDC) analysis of all historic and existing water quality monitoring data from the study area. LDCs will be developed for at least one critical index site per segment. LDCs shall be consistent with 1) EPA's An Approach for Using Load Duration Curves in the Development of TMDLs, 2) EPA's Options for Expressing Daily Loads in TMDLs, and 3) EPA's Development of Duration-Curve Based Methods for Quantifying Variability and Change in Watershed Hydrology and Water Quality. Then, using water quality monitoring data collected by NETMWD through TSSWCB project 09-54, BAEN will refine the developed LDCs.

To estimate loadings from various sources and to identify critical loading areas within the watersheds, BAEN, again with assistance from NETMWD, will conduct watershed modeling for the study area. Utilizing information from the GIS inventory, watershed source survey, and water quality monitoring, and in combination with the LDCs, BAEN will develop a spatially explicit or mass balance model, such as SELECT, for the study area.

To assess and identify different sources contributing to bacteria loadings, SAML will conduct Bacterial Source Tracking (BST) in the study area. SAML will conduct library-independent BST utilizing the Bacteroidales PCR genetic test for human, ruminant, horse, and swine markers. Additionally, SAML will conduct limited library-dependent BST and analyze E. coli isolates utilizing the ERIC-PCR and RiboPrinting combination method. This will serve to confirm that the sources of E. coli and Bacteroidales are comparable and assess the spatial and temporal adequacy of the Texas Known Source Library. The Texas Known Source Library may need to be supplemented with known fecal samples from the study area. NETMWD will provide SAML a subset of water samples collected through TSSWCB project 09-54 for BST. Additionally, NETMWD will collect known fecal samples, if needed. Results from the watershed source survey, to be conducted by NETMWD, will be used by SAML to make appropriate adjustments to the BST sampling design and to assess the adequacy of the Texas Known Source Library. SAML will work with BAEN to integrate BST results into the model, to the extent possible, and address and reconcile discrepancies between BST and modeling results.

Back to Top