EQUIPMENT AND SUPPLIES--The "Iron Horse"--A device for deep-well measurements UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY RESTON, VIRGINIA 22092 GW Branch May 5, 1978 Code 4351 5016 GROUND WATER BRANCH TECHNICAL MEMORANDUM NO. 78.06 Subject: EQUIPMENT AND SUPPLIES--The "Iron Horse"--A device for deep-well measurements For depths to water of greater than about 500 feet, it often is necessary to use equipment to lower and raise water-level measuring devices. Such equipment has been an absolute necessity at the U.S. Energy Research and Development Administration's Nevada Test Site where most of the water levels are deeper than 1,000 feet. Considerable experience has been gained from the operation of various types of water-level measurement devices at the Site. Garber and Koopman, in 1968, in the Techniques of Water-Resources Investigations Book 8, Chapter A1, entitled "Methods of measuring water levels in deep wells" described in detail: (1) various types of water-sensing probes used with an electrical cable well- measuring device referred to as the Iron Horse, and (2) methods to correct for possible sources of errors in measurements. The Iron Horse has proved useful in measuring water levels as deep as 2,600 feet. The device also may be used for obtaining water samples, sounding well depths, and determining vertical fluid velocity. The operation and maintenance of the Iron Horse is described in detail in the enclosed report, entitled "Operation and maintenance of a deep-well water-level measurement device, "The Iron Horse"" by J. E. Weir, Jr., and J. W. Nelson, WRI 76-27. The report should be of interest to all districts concerned with making measurements in deep wells. The Iron Horse is an inventory item that can be ordered from the Geological Survey warehouse. (s) Charles A. Appel (for) Gerald Meyer Chief, Ground Water Branch Enclosure WRD DISTRIBUTION: A and S (memo only); B, FO-L, PO