Administrative Code

Virginia Administrative Code
12/2/2021

Part V. Groundwater Characterization Study (Gcs) and Gcs Well Monitoring Requirements

9VAC25-91-180. Groundwater characterization study (GCS).

A. Section 62.1-44.34:15 of the Code of Virginia requires the operator to apply to the board for approval of an ODCP. The ODCP shall be accompanied by other relevant information required by the board (e.g., groundwater characterization study (GCS) of each facility with an aggregate aboveground storage capacity of one million gallons or greater of oil). The purpose of this GCS is to determine baseline conditions and flow of groundwater within the geographic boundaries of the facility. The operator's results of the GCS shall be subject to the review and approval of the board and shall be submitted to the department as part of the Oil Discharge Contingency Plan (ODCP) referenced in Part IV (9VAC25-91-170, Oil Discharge Contingency Plan (ODCP) Requirements) of this chapter. The GCS wells are required by 9VAC25-91-170 A 13 a in the ODCP requirements.

B. Section 62.1-44.34:15.1 of the Code of Virginia requires that the operator of a facility with an aggregate capacity of one million gallons or greater of oil conduct monthly gauging and inspection, monitoring of well headspace, and quarterly sampling and laboratory analysis of all groundwater monitoring wells located at the facility to determine the presence of petroleum or petroleum byproduct contamination.

C. Although GCS monitoring wells may be approved for use as part of a leak detection system, the GCS well monitoring requirement should not be confused with any requirement for leak detection monitoring wells required by 9VAC25-91-170 A 18.

Statutory Authority

§§ 62.1-44.15, 62.1-44.34:15, 62.1-44.34:15.1 and 62.1-44.34:19.1 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 14, Issue 18, eff. June 24, 1998; Errata, 14:23 VA.R. 3682 August 3, 1998; amended, Virginia Register Volume 31, Issue 26, eff. November 1, 2015.

9VAC25-91-190. GCS well monitoring.

A. All GCS wells required by 9VAC25-91-170 A 13 a in the ODCP requirements shall be monitored as follows:

1. Monthly gauging of GCS groundwater monitoring wells.

a. Measure and record static water levels monthly.

b. Reference all water-level measurements, including total well-depth measurements, from an established and documented point on the top of the well casing.

c. Measurements shall be correlated with mean sea level datum and measured to the nearest 0.01 foot.

2. Quarterly groundwater and vapor monitoring.

a. Quarterly vapor monitoring of all GCS wells identified in the ODCP-GCS shall be conducted prior to collecting quarterly groundwater samples.

b. Quarterly vapor monitoring consists of collecting one monitoring well headspace measurement.

c. Quarterly groundwater sampling (visual inspection) of all wells identified in the ODCP-GCS shall be conducted.

(1) Measure for free product on top of the groundwater.

(2) Collect groundwater samples for visual inspection.

d. Tabulate vapor measurements and quarterly visual groundwater monitoring results for each well sampled.

3. Annual groundwater monitoring for laboratory analysis.

a. Annual groundwater sampling of all wells identified in the ODCP groundwater characterization study (GCS) shall be conducted.

b. Annual groundwater monitoring consists of collecting groundwater samples for laboratory analysis.

c. Groundwater samples shall be collected and analyzed for BTEX and TPH for each well.

B. The GCS groundwater well monitoring should not be confused with the monitoring of groundwater wells utilized to satisfy 9VAC25-91-170 A 18 (i.e., leak detection wells).

Statutory Authority

§§ 62.1-44.2, 62.1-44.15, 62.1-44.34:15, 62.1-44.34:15.1 and 62.1-44.34:19.1 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 14, Issue 18, eff. June 24, 1998.

9VAC25-91-200. Reporting; GCS well monitoring report.

A. All observations and data gathered as a result of the requirements in 9VAC25-91-190 and any other data obtained from those same wells shall be maintained at the facility, compiled, and submitted to the department annually in the following format:

I. Monthly gauging of GCS groundwater monitoring wells.

1.0 Summary of measurement procedures.

2.0 Table of static water levels recorded from monitoring wells.

II. Quarterly GCS groundwater vapor monitoring.

1.0 Summary of groundwater and vapor collection procedures.

2.0 Table of vapor measurements from monitoring well headspace.

3.0 Table of groundwater monitoring well visual inspection results.

III. Annual GCS groundwater quality evaluation.

1.0 Summary of groundwater collection methods.

2.0 Summary of groundwater analytical results and interpretation.

3.0 Table of analytical methods used.

4.0 Table of analytical results.

5.0 Table of field and trip blank results.

6.0 Groundwater laboratory data including chain-of-custody forms.

7.0 Laboratory quality assurance review.

B. The annual GCS monitoring report shall include the facility name and address, operator, and consultant, if any, who prepared the report, contact person and the date the report was submitted.

Statutory Authority

§§ 62.1-44.15, 62.1-44.34:15, 62.1-44.34:15.1 and 62.1-44.34:19.1 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 14, Issue 18, eff. June 24, 1998; amended, Virginia Register Volume 31, Issue 26, eff. November 1, 2015.

9VAC25-91-210. Response.

Should any observations or data indicate the presence of petroleum hydrocarbons in groundwater, the results shall be immediately reported to the board and to the local director or coordinator of emergency services appointed pursuant to § 44-146.19 of the Code of Virginia.

Statutory Authority

§§ 62.1-44.2, 62.1-44.15, 62.1-44.34:15, 62.1-44.34:15.1 and 62.1-44.34:19.1 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 14, Issue 18, eff. June 24, 1998.

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