Texas Administrative Code
Title 16 - ECONOMIC REGULATION
Part 1 - RAILROAD COMMISSION OF TEXAS
Chapter 4 - ENVIRONMENTAL PROTECTION
Subchapter A - OIL AND GAS WASTE MANAGEMENT
Division 4 - REQUIREMENTS FOR ALL PERMITTED WASTE MANAGEMENT OPERATIONS
Section 4.131 - Monitoring

(A) the volume and characteristics of the oil and gas waste to be managed at the facility;

(B) depth to and quality of groundwater within 100 feet below ground surface; and

(C) presence or absence of natural clay layers in subsurface soils.

(A) The operator shall submit a plan for the installation, sampling, and analysis of monitoring wells at the facility. The plan shall include information on the monitor well drilling method. A mud rotary drilling method shall not be used unless the depth to water has been established.

(B) The monitor wells shall be able to provide representative samples of groundwater underlying the site for the duration of facility operations. If a monitor well is not capable of providing a representative sample, the operator shall notify the Technical Permitting Section.

(C) If groundwater is not observed during drilling of the monitor wells, the soil boring shall be advanced to 100 feet. Borings shall be left open for a minimum of 24 hours to determine if groundwater is present.

(D) If shallow groundwater is present within 100 feet below ground surface at the site, a minimum of three groundwater monitoring wells shall be installed. Wells shall be spaced around the facility or pit, close to the facility operational area, with at least two wells on the estimated down-gradient side of the operational area. Additional wells may be required for larger facilities.

(E) The monitor wells shall be completed by a certified water well driller in accordance with 16 Texas Administrative Code, Part 4, Chapter 76 (relating to Water Well Drillers and Water Well Pump Installers).

(F) The monitor wells shall be completed to penetrate the shallowest groundwater zone, and the completion shall isolate that zone from any deeper groundwater zone.

(G) The screened interval of the groundwater monitoring wells shall be designed to intercept at least five feet of groundwater.

(H) The groundwater monitoring well screen shall extend above the static water level.

(I) The sand pack size shall be compatible with the well screen slot size, as well as the local lithology.

(J) The groundwater monitoring well heads shall be protected from damage by vehicles and heavy equipment.

(K) The groundwater monitoring wells shall be maintained in good condition with a lockable watertight expansion cap.

(L) After installation of the wells is complete, the applicant shall submit the following information:

(A) The facility shall not manage oil and gas wastes at the facility until the groundwater monitoring wells are installed, the permittee submits the initial sample results to Technical Permitting Section, and Technical Permitting Section informs the permittee, in writing, that it may commence active operations.

(B) The permittee shall sample the wells after installation of the wells is complete and shall thereafter sample the wells in accordance with the schedule approved by the Technical Permitting Section, or as otherwise required by the Director.

(C) The following measurements and analyses shall be reported to Technical Permitting Section after any sampling event no later than 15 days after the permittee receives the laboratory analysis results: the static water level, pH, and concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX), total petroleum hydrocarbons, total dissolved solids, soluble cations (calcium, magnesium, potassium, and sodium), and soluble anions (bromides, carbonates, chlorides, nitrates, and sulfates).

(D) If any of the parameters identified in subparagraph (C) of this paragraph indicate pollution, or the potential failure of the liner system, the Commission may require additional monitoring events and/or may require analysis of additional parameters.