Michigan Administrative Code
Department - Licensing and Regulatory Affairs
Public Service Commission
Preservation of Records of Electric, Gas, And Water Utilities
Part 2 - SCHEDULE OF RECORDS AND PERIODS OF RETENTION
Section R. 460.2538 - Construction project engineering records; retention period

(1) If a construction project is wholly or partially completed, maps or map reproductions, diagrams, profiles, plans, photographs, records of engineering studies, and similar records in connection with the project shall be retained until these records are superseded or until 6 years after plant is retired, if mortality data are retained.

(2) If construction of the project does not result, the records may be destroyed at option after completely accounting for all expenses incurred.