Idaho Administrative Code
Title IDAPA 37 - Water Resources, Department of
Rule 37.03.05 - MINE TAILINGS IMPOUNDMENT STRUCTURES RULES
Section 37.03.05.035 - PLANS, DRAWINGS, AND SPECIFICATIONS

Universal Citation: ID Admin Code 37.03.05.035

Current through September 2, 2024

The following provisions shall apply in submitting plans, drawings, and specifications.

01. Submission of Plans, Drawings, and Specification. Any owner who shall desire to construct, or enlarge, or alter or repair any mine tailings impoundment structure shall submit duplicate copies of plans, drawings, and specifications prepared by an engineer for the proposed work to the Director with required fees. An owner who desires to construct a continuously raised tailings impoundment structure shall submit duplicate copies of plans, drawings, and specifications prepared by an engineer, showing the stages of lift height, by periods of time, and ultimate design height.

02. Application for and Receipt of Written Approval. Construction of a new mine tailings impoundment structure or enlargement, or non-emergency alteration or repairs on existing mine tailings impoundment structures shall not be commenced until the owner has applied and obtained written approval of the plans, drawings, and specifications covering the work. In emergency situations, the owner shall make the required alterations or repairs necessary to relieve the emergency, and notify the Director.

03. Preparation and Submission of Plans. Plans must be prepared on a good grade of tracing linen or a good quality vellum or mylar. Transparent copies reproducible by standard duplicating processes, if accurate, legible and permanent, will be accepted. Plans may initially be submitted in the form of nonreproducible paper prints. After reviewing the plans, the Director will notify the owner of any required changes.

04. Scale of Plans and Drawings. Plans and drawings shall be of sufficiently large scale with an adequate number of views and proper dimensions, so that drawings may be readily interpreted and studied.

05. Dimensions of Plans. All sheets for a set of plans shall have an outside dimension of twenty-four by thirty-six (24 x 36) inches. A margin of two (2) inches on the left-hand end and a margin of one-half (1/2) inch on the other three sides must be provided, making the available work space twenty-three (23) x thirty-three and one-half (33 1/2) inches.

06. Plans. The plans shall include the following:

a. A topographic map of the mine tailings impoundment structure site showing the location of the proposed mine tailings impoundment structure by section, township and range, and location of spillway or diversion structures, outlet works, and all borings, test pits, borrow pits;

b. A profile along the mine tailings impoundment structure axis showing the locations, elevations, and depths of borings or test pits, including logs of bore hole and/or test pits;

c. A maximum cross-section of the mine tailings impoundment structure showing elevation and width of crest, slopes of upstream and downstream faces, thickness of any proposed riprap, zoning of the earth embankment (if any), location of cutoff and bonding trenches, elevations, size and type of decant systems, valves, operating mechanism, and dimensions of all other essential structural elements such as cutoff walls, filters, embankment zones, etc.;

d. Detailed drawings describing the outlet system, i.e., decant line, barge pump system, siphon system;

e. If a spillway is used, a curve showing the discharge capacity in cubic feet per second of the spillway vs. gage height of the storage pool level above the spillway crest up to the maximum high-water level, and the formula used in making such determinations;

f. If a stream diversion is created, a tabulation of the discharge capacity in cubic feet per second of any diversion works and of the diversion channel vs. flow depth through the diversion works or channel up to maximum capacity of the system, and the formulas used in making such determinations;

g. Where staged construction will take place and no spillway exists, a curve showing maximum safe operating level for the tailings as a function of embankment height and the design criteria used to arrive at this;

h. Detailed plans, including cross-sections and profile, of the spillway or diversion works and any associated channels;

i. Plans for monitoring and/or recovering seepage from the reservoir in those instances where safety of the impoundment may be affected;

j. An operation plan;

k. An emergency procedure plan for protection of life and property;

l. An abandonment plan that assures the Director to his satisfaction that, upon completion of the mining operation, the site will be in a safe maintenance-free condition.

07. Specifications. Specifications shall include provisions acceptable to the Director for adequate observation, inspection and control of the work by a registered professional engineer during the period of construction.

08. Provision Included with Plans. The specifications shall provide that the plans and specifications may not be materially changed without prior written consent of the Director.

09. Provisions Included with Specifications. The specifications shall provide that certain stages of construction shall not proceed without the approval of the Director. Those stages requiring approval are as follows:

a. After clearing and excavation of foundation and prior to placing any fill material;

b. After installation of the decant conduit and any proposed collars and before placing any backfill material around conduit;

c. After construction is completed (first stage starter dike if staged construction) and before any water or mine tailings slurry is stored in the reservoir;

d. Before each successive enlargement of the impoundment structure;

e. After each stage of enlargement of the impoundment structure is completed and before storage is allowed to exceed the level approved for the previous approved stage;

f. At such other times as determined necessary by the Director. The Director will, within seven (7) days after notification by the engineer, inspect and if satisfactory, approve the completed stage of construction. Owners are encouraged to give prior notice to the Department, so that the inspection can be scheduled to prevent delays.

10. Inspections, Examinations, and Tests. All materials and workmanship may be subject to inspection, examination and test by the Director at any and all reasonable times during manufacture and/or construction and at any and all places where such manufacture and/or construction are carried on.

11. Rejection of Defective Material. The Director shall have the right to require the owner or engineer to reject defective material and workmanship or require its correction. Rejected workmanship shall be corrected and rejected material shall be replaced with proper material.

12. Suspension of Work. The Director may order the engineer to suspend any work that may be subject to damage by climatic conditions.

13. Responsibility of Engineer. These provisions shall not relieve the engineer of his responsibility to assure that construction is accomplished in accordance to approved plans and specifications or to suspend work on his own motion.

14. Detailing Provisions of Specifications. The specifications shall state in sufficient detail, all provisions necessary to ensure that construction is accomplished in an acceptable manner and provide needed control for construction to ensure that a safe structure is constructed.

15. Required Information. The following information shall be submitted with the plans and specifications.

16. Engineer's Report. An engineer's report giving details necessary for analysis of the structure and appurtenances. Included as a part of the report where applicable shall be the following:

a. Formulas and assumptions used in designs;

b. Hydrologic data used in determining runoff from the drainage areas;

c. Engineering properties of each type of material to be used in the embankment and of the foundation areas;

d. Stability analysis, including an evaluation of overturning, sliding, upstream and downstream slopes and foundation stability;

e. Geologic description of reservoir area, including evaluation of landslide potential;

f. Chemical analysis of all materials composing the slurry;

g. Earthquake design loads must be evaluated at all sites located east of Range 22 E., Boise Meridian. This area corresponds to Seismic Zone 3 as designated by the Recommended Guidelines of the National Dam Safety Program. Earthquake analysis may be required at other impoundment structure sites if deemed necessary by the Director;

h. A seepage analysis of the embankment and reservoir bottom;

i. A hydraulic analysis of the outlet system and spillway, diversion work or diversion channel;

j. Engineering properties and the weathering characteristics of the proposed tailings to be stored in the impoundment;

k. Other information which would aid in evaluating the safety of the design.

17. Filing of Additional Information. The Director may require the filing of such additional information which in his opinion is necessary to assess safety or waive any requirement herein cited if in his opinion it is unnecessary.

Effective March 30, 2023

Disclaimer: These regulations may not be the most recent version. Idaho may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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