020-11 Wyo. Code R. §§ 11-19 - Excursions

(a) "Confirmation" of an excursion occurs when an excursion detected in a regularly scheduled sampling event is subsequently detected in a second or third sampling event conducted in accordance with the following requirements:

(i) The second sampling event shall be conducted within 24 hours of the receipt of the results from the first sampling event in which the excursion was initially detected. If the results from the first and second sampling event both indicate an excursion has occurred, then the excursion will be considered confirmed for the purpose of meeting the reporting requirements of W.S. § 35-11-429(a)(i).

(ii) If the results from the first and second sampling events provide conflicting information about whether or not an excursion has occurred, then a third sampling event must be conducted within 24 hours of the receipt of the results from the second sampling event. However, if the results of the confirmatory sampling are not complete within thirty days of the initial sampling event which indicated an excursion might be present, then the excursion will be considered confirmed for the purpose of meeting the reporting requirements of W.S. § 35-11-429(a)(i).

(b) The operator shall:

(i) Verbally report any confirmed excursion to the Administrator within 24 hours of confirmation of the excursion; and

(ii) Submit a written report to both the Administrator and the Water Quality Division within five days of the confirmation of the excursion detailing the procedures for mitigating or controlling the excursion.

(c) An excursion is controlled when it can be demonstrated through water quality and groundwater gradient or if applicable, pressure measurements, that recovery fluid in unauthorized areas is declining.

(i) If an excursion is not controlled within 30 days following confirmation of the excursion, a sample must be collected from each of the affected monitoring wells and analyzed. The parameters to be analyzed shall be site specific and based on baseline data.

(ii) If an excursion is not controlled within 60 days following confirmation of the excursion, the Administrator may, after consultation with the Director, terminate the mining operation and revoke the permit or Research and Development License or modify the mining operation and require modification of the permit or Research and Development License. Modifying the operation may include: sampling of additional wells for the parameters in Section 19(c)(i); installation of additional monitor wells; termination of injection in the portion of the well field in which the excursion originated; or a combination of approaches to assure control within the necessary time frames.

(iii) If the excursion is controlled, but the fluid which moved out of the production zone during the excursion has not been recovered within sixty days following confirmation of the excursion (i.e., the monitor well is still "on excursion"), the operator shall submit, within ninety days following confirmation of the excursion, a plan and compliance schedule, acceptable to the Department, for bringing the well(s) off excursion. The plan and compliance schedule can be submitted as part of the monthly excursion report required in Section 19(d) of this Chapter. The compliance schedule shall meet the requirements of Section 20(b) of this Chapter.

(d) In addition to the excursion notifications and control plan required above, a monthly report on the status of an excursion shall be submitted to the Administrator beginning the first month the excursion is confirmed and continuing until that excursion is over. The monthly report shall be a requirement of the compliance schedule and shall include, at a minimum:

(i) Concentrations of UCL parameters and groundwater elevations in all monitoring wells on excursion and, as necessary, surrounding wells;

(ii) Such information deemed necessary by the Administrator to show that the excursion is being controlled and that the bond amount for groundwater restoration remains sufficient; and

(iii) Information on steps taken to control the excursion.

Notes

020-11 Wyo. Code R. §§ 11-19

Amended, Eff. 11/13/2018. Amended, Eff. 11/17/2022.