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within the proposed permit and adjacent areas needs to be provided. Special attention should be given to the identification of aquifers and aquifer re- charge zones [see definition of renewable lands under Section 1.04(10) of the Colorado permanent regulatory program]. (b) The applicant eludes to the possible difficulties involved with room -and- piller retreat extraction. The application observes that "unpredictable pillar failures" may occur for over 100 years following mining. The appli- cation further observes that subsidence will result in trough depressions of up to 6 feet over longwall mined areas and possibly four feet above room - and-piller mined sections. The application also observes that the predicted horizontal strain above the subsided mine working will result in surface cracking possibly of several inches in width. The applicant should include a thorough discussion of the potential impacts this phenomena could have upon the surface and renewable resource lands, including aquifers and areas of recharge to aquifers. Without this information it will be impossible to render a finding concerning impacts upon the hydrologic balance within the project area. A constant appears to have been omitted from the equation shown on the fig- ure on page III -14T of the application. There are two tables within this section of the application, both bearing the number III -1A, which should be corrected to eliminate confusion. (c) Sufficient evidence is not presented within the amended aplication to sup- port the statements on page III -14DD and page III -15, regarding the mechan- ics of the expected subsidence. The applicant proposes once - per -shift "mon- itoring" of county route 65 and the Red Wash surface drainage. This is a commendable operational approach to assuring conformance with the perfor- mance standards of Rule 4.20 of the Colorado permanent regulatory program, -19-