UNITED STATES DEPARTMENT OF THE INTERIOR
MINERALS MANAGEMENT SERVICE

Revised North American Datum 83 Implementation Plan for the Gulf of Mexico

This Notice to Lessees and Operators (NTL) is issued pursuant to 30 CFR 250.103 and supersedes NTL No. 99-G17, effective July 8, 1999, on this subject.  It notifies you of the changes the Minerals Management Service (MMS) Gulf of Mexico OCS Region (GOMR) is making to the North American Datum (NAD) 83 Implementation Plan for the Gulf of Mexico.

Background

On May 1, 1991, the MMS published in the Federal Register (56 FR 20020) an implementation plan for converting the offshore cadastre from NAD 27 to the NAD 83.  In the MMS GOMR, Phase I of this plan specifies that all location data pertaining to drilling activities, wells, platforms, pipelines, or any other activities or facilities must specifically reference either NAD 27 or NAD 83.  As announced in a February 12, 1992, Federal Register Notice (57 FR 5168), any NAD 83 to NAD 27-converted equivalents are to be derived using NADCON software, version 2.0 or better. 

Reporting Guidance Changes

The MMS GOMR is making certain changes concerning how you report surface location data and final location plats pertaining to drilling activities, wells, platforms, pipelines, or any other activities or facilities.  To ensure that this information is sufficiently accurate, the MMS GOMR is revising its NAD 83 implementation plan as follows:

1. You will report all “as-drilled” and “as-built” surface location data in NAD 83.
2. You will continue to submit all “as-drilled” and “as-built” location plats in NAD 27.  However, on the plats, you will list latitude and longitude coordinates in both NAD 83 and NAD 27, and X-Y coordinates and block-line departure measures in NAD 27.
3. You will continue to report all “proposed” surface location data in NAD 27.
4. You will continue to submit all “proposed” surface location plats in NAD 27.

Do not make any changes in your submittals until the MMS issues subsequent NTL’s to provide you with specific guidance and effective dates concerning the use of revised forms, location plats, and/or data file formats.

Implementation Plan

Please note that the MMS GOMR remains in this modified Phase I of NAD 83 implementation for the foreseeable future.  The offshore cadastre used by the MMS GOMR will continue to be defined on NAD 27, and the MMS GOMR will convert your submitted NAD 83 “as-drilled” and “as-built” surface location data to NAD 27 equivalents using the NADCON software.  When appropriate, the MMS GOMR will make NAD 83 equivalents available.

As before, the MMS GOMR has no plans to move to Phases II or III of the NAD 83 Implementation Plan at this time, nor has the MMS GOMR established a schedule to accomplish this task.

Paperwork Reduction Act of 1995 Statement

This NTL provides clarification, description, or interpretation of requirements in MMS regulations and related forms on drilling and well activities.  The Office of Management and Budget (OMB) has approved the information collection requirements referred to in this NTL.  The assigned OMB control numbers are on the forms or are specified in the regulations.  This NTL does not impose additional information collection requirements subject to the Paperwork Reduction Act of 1995.

Contact

Please address any questions on this notice to Mr. Chris Gaudry by telephone at (504) 736-2887 or by e-mail at tdms@mms.gov.

Chris C. Oynes
Regional Director

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