Section 95. Groundwater baseline sampling, analysis, and monitoring plan

A. Each application for a permit shall include a groundwater baseline sampling, analysis, and monitoring plan. The groundwater monitoring program will consist of initial baseline groundwater sampling and testing followed by subsequent sampling and testing after setting the production casing or liner.

B. If four or fewer available groundwater sources are present within a one-quarter-mile radius of the location of a proposed oil or gas well, or department-approved monitoring well, the operator shall collect a sample from each available groundwater source.

C. If more than four available groundwater sources are present within the one-quarter-mile radius, the operator shall submit a plan for approval to the director for selecting the available groundwater sources based on all of the following criteria:

1. Available groundwater sources closest to the location of the (i) proposed oil or gas well, (ii) department-approved monitoring well, or (iii) multi-well pad are preferred.

2. Sample locations shall be chosen in a radial pattern around the permitted location.

3. Where available groundwater sources are present in different aquifers, a sample shall be collected from each aquifer. Where multiple available groundwater sources are present in a single aquifer, an operator shall give adequate consideration to vertical separation and aquifer zones in selecting available groundwater sources for sampling.

4. If groundwater flow direction is known or reasonably can be inferred, samples from both upgradient and downgradient available groundwater sources are required, if available.

D. The initial sampling and testing shall be conducted within the 12-month period prior to drilling the well or the first well on a multi-well pad. Subsequent sampling and testing shall be conducted between six and 12 months after setting the production casing or liner. An operator shall make a reasonable attempt to conduct all sampling during the same month of the year. An operator may request in writing approval from the director to deviate from these sampling and testing timeframes in its permit application based on site specific geologic and hydrologic conditions (e.g., flow rate and direction). Previously sampled groundwater sources, including samples obtained by other operators, may be used if collection of the sample or samples meets all of the requirements of this section and are approved by the director.

E. All samples collected pursuant to this section shall be analyzed and tested by a laboratory certified or accredited under the Virginia Environmental Laboratory Accreditation Program established in 1VAC30-45 and 1VAC30-46.

F. Copies of all final laboratory analytical results and spatial coordinates of the available water source shall be provided by the operator or its representative to the department and water source owner within three months of sample collection. All analytical results and spatial coordinates of the available water source shall be made available to the public by the department.

G. The initial and subsequent sampling and testing described in this section shall, at a minimum, include the following items:

1. Chlorides;

2. Total dissolved solids;

3. Dissolved gases (methane, ethane, propane);

4. Hardness;

5. Iron;

6. Manganese;

7. pH;

8. Sodium; and

9. Sulfate.

Field observations such as odor, water color, sediment, bubbles, and effervescence shall also be documented. Handheld detection devices shall be sufficient for testing for methane.

H. If free gas or a dissolved methane concentration greater than 10.0 milligrams per liter (mg/L) is detected in a water sample, gas compositional analysis and stable isotope analysis of the methane (carbon and hydrogen – 12C, 13C, 1H, and 2H) shall be performed to determine gas type.

I. The operator shall provide verbal and written notification to the director and groundwater source owner within 24 hours if test results indicate:

1. The presence of thermogenic or a mixture of thermogenic and biogenic gas;

2. The methane concentration increases by more than 5.0 mg/L between sampling periods;

3. The methane concentration is detected at or above 10.0 mg/L; or

4. Exceedances of the parameters listed in 9VAC25-280-70.

J. Upon receiving notification pursuant to this subsection, the director shall have the authority to order an additional sampling test to be completed within six months of the test that resulted in the notification. This authority is in addition to enforcement actions the director may utilize pursuant to 4VAC25-150-170.

Historical Notes

Derived from Volume 33, Issue 07, eff. December 28, 2016.

Statutory Authority

§§ 45.1-161.3, 45.1-361.4, and 45.1-361.27 of the Code of Virginia.