with these Mineral Leasing Acts, for the purpose of prospecting for or mining potash, oil shale, sodium, phosphate, sulphur, gold, silver, or quicksilver.** [Preamble] 231.3 Powers and duties of mining supervisor. It shall be the duty of the mining supervisor, individually or through his subordinates, and under the direction of the Director of the Geological Sur vey: (a) Make inspectional visits; supervise operations to prevent waste or damage; promote safety, health, and welfare of workmen; issue necessary orders or instructions. To visit from time to time leased lands where operations for the discovery or mining or treating of potash, oil shale, sodium, phosphate, sulphur, gold, silver, or quicksilver are carried on or are to be conducted; to inspect and supervise such operations, including operations at accessory plants, for the purpose of preventing waste of mineral substances, or damage to formations or deposits containing them, and of promoting the safety, health, and welfare of workmen in accordance with the provision of the acts; and to issue, in accordance with the provisions of the lease and the regulations in this part, such necessary orders or instructions not in conflict with the laws of the State in which the leased lands are situated as will effectively carry out the purposes aforementioned. (b) Make reports on condition of leased property and manner of operations; make recommendations for safeguarding lives and health of employees and protection of property. To make reports to the Director of the Geological Survey and to the Secretary of the Interior as to the general condition of the leased property and the manner in which operations are being conducted and orders or instructions are being complied with, and to submit from time to time information and recommendations for safeguarding and protecting the lives and health of the employees, the property, the minerals, and the mineral-bearing formations. (c) Prescribe manner and form of records, reports, and notices. To prescribe, subject to the approval of the Secretary of the Interior, the manner and form in which all records of operations, reports, and notices shall be made. (d) Obtain and check records of production; report amount of production and value of accrued rentals and royalties. To obtain and check the records of production of minerals from the leased lands and to report at the end of each quarter the amount of production and the value of accrued rentals and royalties chargeable to each lease.* [Secs. 1-4] 231.4 General obligations of lessees. Mining operations by the lessee shall conform to the terms of the Act, the lease, and the regulations in this part and to the written instructions of the mining supervisor and his subordinates, and shall use all reasonable precautions, in accordance with the most approved methods, to prevent waste, damage to mineral-bearing formations, and injury to life or health, and shall provide for safety and welfare of the employees.** [Sec. 5] Page 68 **For statutory and source citations, see note to § 231.1. MAPS AND PLANS 231.5 Maps and plans required prior to beginning commercial operations; modification thereof; departure therefrom; operations in advance of approval thereof or not in conformity therewith. Prior to the beginning of actual commercial mining operations maps and plans showing the proposed mining methods and the plant layout shall be submitted to the district mining supervisor for approval. Such maps and plans shall be modified as required by the mining supervisor, and when approved shall be put into execution. If subsequent operations require radical departure from the approved maps and plans, supplementary maps and plans shall be submitted with a statement of reasons for the changes. Operations conducted in advance of approval of such maps and plans by the district mining supervisor or not in conformity with approved maps and plans constitute violation of the regulations in this part.* [Sec. 8] 231.6 Requirements for maps of underground workings and surface operations and equipment; accuracy to be attested before notary public; posting. Maps of underground workings, unless otherwise ordered by the mining supervisor, shall be drawn to a scale of 100 feet to the inch; maps of surface operations and equipment may be to a scale of not over 200 feet to the inch. All maps shall be appropriately marked with reference to Government landmarks or lines and elevations with reference to sea level. Where the beds or deposits dip at angles greater than 45° from the horizontal, vertical projections and cross sections shall be made accompanying plan views. Maps shall be based on accurate surveys made within 30 days following January 1 and July 1 of each year and as may be necessary at other times. Accurate copies of such maps on tracing cloth or prints shall be furnished the mining supervisor when and as required. The accuracy of maps furnished shall be attested before a notary public. The maps shall be posted to date at least once each six months.* [Sec. 7] 231.7 Other maps; what to be shown. The lessee shall prepare such maps of the leased lands as in the judgment of the mining supervisor are necessary to show the surface boundaries, improvements, and topography, and the geological conditions so far as determined from outcrops, drill holes, prospecting, or mining. All excavations in each separate bed or deposit shall be shown in such manner that the production of minerals for any given royalty period can be accurately ascertained.*+ [Sec. 6] PROSPECT BORE HOLES 231.8 Submission of core or test hole records; cores, samples, cuttings, mill products; cementing and casing of drill holes. The lessee shall submit promptly to the mining supervisor sworn copies of all core or test hole records made on the leased lands, the records to be in such form that the position and direction of the holes can be accurately located on a map. The records shall include a log of all strata penetrated and conditions encountered, such as **For statutory and source citations, see note to § 231.1. Page 69 water, quicksand, gas, or unusual conditions, and copies of analyses of all samples analyzed from strata penetrated shall be transmitted to the district mining supervisor as soon as obtained. The core from test holes shall be available for inspection at the convenience of the district or deputy mining supervisor, and he shall be privileged to cut such cores and receive samples of such parts as he may deem advisable, or on request of the mining supervisor the lessee shall furnish such samples of strata, drill cuttings, and mill products as may be required. Drill holes for development or holes for prospecting shall be cemented and cased to the satisfaction of the mining supervisor and in a manner not to endanger any present or future underground operation or any deposit of oil, gas, or other mineral substances.*f [Sec. 9] WELFARE AND SAFETY 231.9 Sanitary, welfare, and safety arrangements. The underground and surface sanitary, welfare, and safety arrangements shall be in accordance with the recommendations of the United States Public Health Service and United States Bureau of Mines.** [Sec. 10] CROSS REFERENCES: For United States Bureau of Mines, see Chapter I. For United States Public Health Service, Department of the Treasury, see 42 CFR Chapter I. 231.10 Reports of accidents, inundations, or fires to be promptly mailed; fatal accidents and serious or threatening damages to be reported by telegraph or telephone. Full reports of all accidents, inundations, or fires shall be promptly mailed to the district mining supervisor by the lessee or his representatives. Fatal accidents and serious or threatening damages to the mine, the leased lands, or deposits, shall be reported to the district mining supervisor by telegraph or telephone.*+ [Sec. 11] 231.11 Protection of employees; mechanical equipment; dangerous walks or passages; moving parts of machinery or belts. All employees while in the mine or accessory plants shall be afforded all possible protection to life and health. All mechanical equipment used for the transportation of men shall be of a safe design and character for the work it performs. At dangerous walks or passages adequate shelter holes shall be made, guard rails or fences shall be erected, and warning signs shall be posted. All moving parts of machinery or belts, when endangering employees or liable to result in injury, shall be adequately guarded.* [Sec. 12] MINING METHODS 231.12 Lessee shall observe good practice. The lessee shall observe good practice in prospecting and mining, sinking wells, shafts, and winzes, driving drifts and tunnels, stoping, blasting, transporting ore materials, hoisting, the use of explosives, timbering, pumping, and other operations for the development and preservation of any operation, mine, or mine equipment on the lease.* [Sec. 20] 231.13 Operations shall be conducted in a manner to yield ultimate maximum recovery; information recorded and copy fur Page 70 *For statutory and source citations, see note to § 231.1. nished district mining supervisor. Mining operations shall be conducted in a manner to yield the ultimate maximum recovery of the mineral deposits. All shafts, main exits, and passageways, as well as overlying beds or mineral deposits that at a future date may be of economic importance, shall be protected by adequate pillars in the deposit being worked. Information obtained regarding the mineral deposit being worked and other mineral deposits on the leased lands shall be fully recorded and a copy of the record furnished to the district mining supervisor.* [Sec. 21] Sufficient pillars shall be maximum recovery when Boundary pillars shall in 231.14 Sufficient pillars shall be left. left in first mining to insure the ultimate the time arrives for the removal of pillars. no case be less than 50 feet thick unless otherwise specified in writing by the mining supervisor. Boundary and other main pillars shall be mined only with the written consent or by order of the mining supervisor or his authorized subordinates.*+ [Sec. 22] 231.15 Working places; traveling way. All working places shall be visited at least once during each shift by the mine foreman or his assistants, and there shall be provided adequate timber distributed throughout the mine for the usual daily uses. The roof and sides of every traveling way and each working place shall be made secure when necessary by timbering or adequate lining and arching in accord with good mining practice and the lessee shall not permit anyone to travel on or work in any traveling way or working place which is not secure, unless appointed for the purpose of exploring, inspecting, or repairing same.* [Sec. 23] 231.16 Mining or prospecting minerals soluble in water; brines; minerals taken in solution. In mining or prospecting deposits of potassium or other minerals soluble in water, all wells, shafts, prospect holes, and other openings shall be adequately protected with neat cement against the coursing or entrance of water; and the lessee shall, on orders of the mining supervisor, back fill with rock or other suitable material to protect the roof from breakage when there is a danger of the entrance of water. On leased lands containing brines, due precaution shall be exercised to prevent the deposits becoming diluted or contaminated by the mixture of water or valueless solution; and, where the minerals are taken from the earth in solution, such extraction shall not be within 500 feet of the boundary line of the leased lands without the written permission of the Secretary of the Interior.** [Sec. 24] PROTECTION AGAINST MINE HAZARDS 231.17 Dust, fumes, and acids. In the mining and milling or treating of the ores or mined products, the employees shall be adequately protected from injurious fumes, acids, dusts, and harmful or dangerous conditions. In mines where siliceous or other harmful dusts are formed, drilling machines shall be of the water-injection type and sprays shall be used to wet down the dust.*+ [Sec. 13] 231.18 Ventilation. Lessees shall provide and maintain for each underground operation on any lease a good and sufficient amount of *For statutory and source citations, see note to § 231.1. Page 71 ventilation for such men and animals as may be employed therein, and shall cause an adequate quantity of normal air to circulate through and into all the shafts, winzes, levels, and all working places of such mine. A working place, entry, or passageway shall not be deemed normally in a fit condition for men to work or travel in if the air therein be found by chemical analysis to contain on a moisturefree basis more than 14 percent carbon dioxide or less than 1912 percent oxygen. The lessee, upon being notified of such finding, shall immediately undertake measures to improve the quality of the air of said working place or entry. Where natural ventilation does not furnish a positive current of air, ventilating fans shall be provided. Fans when installed shall have fireproof housing and surface fans shall be so arranged that the ventilating current can be quickly reversed.* [Sec. 14] 231.19 Inflammable gas and dust. Mines in which inflammable gas is found or explosive dust produced shall be subject to the coalmining operating regulations covering these hazards.*† [Sec. 15] CROSS REFERENCE: For coal-mining operating regulations, see Part 211. 231.20 Explosives. The lessee shall store, thaw, transport, issue, and use explosives only in the most approved manner and with due regard for the safety and welfare of the employees and protection of property and in accord with instructions or notices issued by the mining supervisor.*+ [Sec. 16] 231.21 Electricity. Electric circuits with potential of more than 600 volts shall be conducted in or through a mine only through insulated lead-covered armored cables, with the armor electrically continuous throughout and grounded, and may only be used for transmission or for application to transformers, motors, or other apparatus in which the whole of the high-voltage winding is stationary. Electric circuits of between 300 and 600 volts may be used only for stationary motors. All portable motors, such as locomotive mining machinery and portable pumps or portable fans, shall use current of less than 300 volts. All electric wires and appliances shall be installed, maintained, and used so as to insure safety to the employees and the mine and be in accord with the recommendations of the United States Bureau of Mines.*+ [Sec. 17] 231.22 Fire protection. All structures within 75 feet of any mine opening shall be so constructed and protected against fire that the men in the mine shall not be endangered if fire should occur in a surface building. Inflammable material shall not be stored within 75 feet of a mine exit. All shafts shall be fireproof. All underground offices, stations, shops, magazines, and stores shall be so constructed, equipped, and maintained as to reduce the fire hazard to a minimum. Sufficient fire-fighting apparatus shall be maintained in working condition at the mine exits and at convenient points in the mine workings for fire emergencies. An adequate water supply shall be held in storage tanks or reservoirs for fire emergencies and be available for immediate use through connecting pipe lines for either surface or underground fires.*t [Sec. 18] Page 72 **For statutory and source citations, see note to § 231.1. |