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Eagle Ford Shale Geological Area

The Eagle Ford Shale is a hydrocarbon-producing geological formation extending over 26 counties. It stretches from the Mexican border between Laredo and Eagle Pass up through counties east of Temple and Waco.


The TCEQ’s primary role in the oil and gas fields is regulating emissions and ensuring air quality. Working with the Railroad Commission, which has primary jurisdiction over oil and gas facilities in Texas, the TCEQ is devoting significant resources to make sure those responsibilities are met. Based on lessons learned from the TCEQ’s work in the Barnett Shale area, numerous activities have already been conducted or will soon take place to help the agency remain in front of any environmental issues in the Eagle Ford Shale area.

The TCEQ continues to use innovative approaches to find ‘real world solutions’ that actually reduce emissions. The TCEQ has undertaken numerous projects that use state-of-the-science technology to assess and address emissions from oil and gas activities. These initiatives have resulted in emissions reductions through improved agency policies, guidance for regulated entities and possible enforcement if necessary.

Map of Eagle Ford Shale area

Air Monitoring

Near-real-time air monitoring results from the agency’s air monitors located in the Eagle Ford Shale area:

Floresville Hospital Boulevard (Wilson County) Ambient Monitoring Station

Karnes County Courthouse Ambient Monitoring Station

Sampling Results and Health Effects Evaluations by County

TCEQ laboratory analysis, listed by county, of air sampling conducted near oil and/or natural gas facilites in the Eagle Ford Shale area. Health effects evaluations for air sampling results are posted as they become available.

24-Hour Canister Monitoring

The Texas Air Monitoring Information System (TAMIS)
TAMIS is a TCEQ Web interface that can generate a report showing VOC data collection at the 24-hour Laredo Bridge canister in Webb County.

Air Monitoring Comparison Values

AMCV is a collective term used to describe chemical-specific air concentrations used to evaluate air monitoring data that are set to protect human health and welfare. Ambient air monitoring results are compared to AMCVs to determine whether exposure to the measured concentrations have the potential to cause adverse health effects, odors, or vegetation effects.

Eagle Ford Shale Mobile Monitoring Study

TCEQ has funded a Mobile Monitoring Study of upwind and downwind monitoring of VOCs and NOx concentrations to evaluate any significant differences in the concentration of ozone precursors.

Related Links

Latest Activities

New Karnes County Courthouse Ambient Monitoring Station:

Karnes County Automated Gas Chromatograph
(AutoGC) data

Karnes County Site Information

Eagle Ford Map

The following map shows oil and gas wells for the Eagle Ford Shale area.

Map of Wells in Eagle Ford Shale

Map provided by the Texas Railroad Commission .