(1) Surface water monitoring must be based on information submitted pursuant to ARM 17.24.304 and must be conducted in accordance with the monitoring program submitted under ARM 17.24.314 and approved by the department. Monitoring must:

(a) be adequate to measure accurately and record water quantity and quality of all discharges from the permit area;

(b) in all cases in which analytical results of the sample collections indicate noncompliance with a permit condition or an applicable standard, result in the operator immediately taking appropriate remedial measures. Within five days of the discovery of the noncompliance, the operator shall notify the department of the noncompliance and of the remedial measures taken and shall comply with (6). These remedial measures include, but are not limited to, accelerated or additional monitoring, abatement, and warning of all persons whose health and safety is in imminent danger. Whenever a violation of a Montana pollutant discharge elimination system (MPDES) permit occurs, the operator shall forward the analytic results concurrently with the written notice of noncompliance;

(2) The operator shall submit semi-annual reports including analytical results from each sample taken during the semester to the department. Sampling results must be submitted in a format approved by the department. In addition, all monitoring data must be maintained on a current basis for review at the minesite. Any sample results that indicate a permit violation must be reported immediately to the department. However, whenever the discharge for which water monitoring reports are required is also subject to regulation by a MPDES permit and that permit requires filing of the water monitoring reports within 90 days or less of sample collection, the operator shall submit to the department on the time schedule required by the MPDES permit or within 90 days following sample collection, whichever is earlier, a copy of the completed reporting form filed to meet MPDES permit requirements.

(3) Monitoring must be conducted at appropriate frequencies to measure normal and abnormal variations in concentrations.

(4) After disturbed areas have been regraded and stabilized according to ARM 17.24.501, the operator shall monitor surface water flow and quality. Data from this monitoring must be used to determine whether the quality and quantity of runoff without treatment is consistent with the requirements of this rule to minimize disturbance to the prevailing hydrologic balance, to demonstrate that the drainage basin has stabilized to its previous, undisturbed state, and to attain the approved postmining land use. These data must also be used by the department to review requests for removal of water quality or flow control systems and for bond release. With department approval, other information or methods, such as models, may be used, in conjunction with monitoring data, for these purposes.

(5) Equipment, structures, and other devices necessary to measure and sample accurately the quality and quantity of surface water discharges from the disturbed area must be properly installed, maintained, and operated and must be removed when no longer required.

(6) Methods of sample collection, preservation, and sample analysis must be conducted in accordance with 40 CFR Part 136 titled "Guidelines Establishing Test Procedures for the Analysis of Pollutants" (July 2015) and Part 434 titled "Coal Mining Point Source Category BPT, BAT, BCT Limitations and New Source Performance Standards" (January 2002), and the June 2019 edition of the department's document titled "Department Circular DEQ-7, Montana Numeric Water Quality Standards." Copies of 40 CFR Part 136, 40 CFR 434, and Department Circular DEQ-7 are available at the Department of Environmental Quality, 1520 E. 6th Ave., P.O. Box 200901, Helena, MT 59620-0901. Sampling and analyses must include a quality assurance program acceptable to the department.

(7) Surface water monitoring must proceed through mining and continue until phase IV bond release. The department may allow modification of the monitoring under the same criteria as are contained in ARM 17.24.645(5).