PROGRAMS AND PLANS - Use of longitude-latitude for well numbers in 5-year water level reports UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY WATER RESOURCES DIVISION WASHINGTON 25, D. C. October 11, 1963 Code 4056 0001 GROUND WATER BRANCH MEMORANDUM NO. 64.10 To: District Chiefs and Staff Officials (GW) From: Chief, Ground Water Branch Subject: PROGRAMS AND PLANS - Use of longitude-latitude for well numbers in 5-year water level reports The well numbering system described in Ground Water Branch memo 64.8, dated September 24, 1963, has been adopted for use in the 5- year water level reports. All wells for which data are to be published should be assigned numbers according to the system described in the reference memorandum. The first report affected by this directive is for water levels in the Southeast United States for the period ending December 31, 1963. All wells should be located as accurately as possible. We recognize that the quality of maps available throughout the country is not uniform. Hence, wells in some areas cannot be located to the nearest second of longitude and latitude. Therefore, the number assigned should reflect the highest degree of accuracy possible. When necessary, rounding off to the nearest five or ten seconds or even to half a minute is permissible. When numbers are rounded insert zeros for missing digits. Also, the last digit of the well number which indicates sequential scheduling is to be used even though no other wells may be near by. In this case the number one should be inserted. Thus the number of digits will be the same as the number of columns set up for the well number in the proposed punch card system for storage of well inventory data. (s) A. H. Lang for O. M. Hackett WRD Distribution: A, B3, S3, FO3, SL