PROGRAMS AND PLANS - Use of latitude-longitude for well numbers UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY WATER RESOURCES DIVISION WASHINGTON 25, D. C. September 24, 1963 4056 0001 GROUND WATER BRANCH MEMORANDUM NO. 64.8 To: District Chiefs and Staff Officials - Ground Water From: Chief, Ground Water Branch Subject: PROGRAMS AND PLANS - Use of latitude-longitude for well numbers The Ground Water Branch is in the process of devising an IBM punch-card system for storage of well inventory data. A meeting was held in Miami, Florida the week of September 16, 1963, to discuss the system and to determine what information should be put on the cards. Those attending the meeting included Branch personnel from throughout the country, plus Branch Area Chiefs and staff officials from the Washington office. All agreed unanimously that the system should be adopted and that the data card should be designed for nationwide use. A uniform method of well numbering for use by all district and project offices also was recommended. This would utilize latitude and longitude to the nearest second which would describe an approximately square area about 100 feet on a side. The punch- card system allots 15 columns to the well number--7 for longitude, 7 for latitude, and 1 for sequential numbering of wells in a square. The numbering system as set up is actually appropriate for world-wide adoption in that longitude would be reckoned only in a westerly direction starting with the Greenwich, England meridian and going from 0 degrees to 360 degrees; latitude designation would include identification of northern or southern hemispheres. For example, a well in Texas located at 102 degrees 15' 35" W and 31 degrees 45' 12" N would have the number 1021535314512N3; a well in New Jersey may have the number 0742510402130N1. The first 7 numbers indicate degrees, minutes and seconds of longitude, the next 6 indicate degrees, minutes, and seconds of latitude; the letter indicates northern hemisphere; and the last number indicates the scheduling sequence in the 100- foot square formed by the seconds of latitude and longitude. The punch-card format is to be completed shortly. In the meantime, it is recommended that the numbering system described above be put into use immediately. (s) A. H. Lang for O. M. Hackett WRD Distribution: A, B3, S3, FO3, SL