DEPARTMENT OF LICENSING AND REGULATORY AFFAIRS  
PUBLIC SERVICE COMMISSION  
PRESERVATION OF RECORDS OF ELECTRIC, GAS, AND STEAM UTILITIES  
Filed with the secretary of state on November 18, 2021  
These rules take effect immediately upon filing with the secretary of state unless adopted under  
section 33, 44, or 45a(6) of the administrative procedures act of 1969, 1969 PA 306, MCL 24.233,  
24.244, or 24.245a. Rules adopted under these sections become effective 7 days after filing with  
the Secretary of State.  
(By authority conferred on the public service commission by section 5 of 1919 PA 419 and  
section 4 of 1939 PA 3, MCL 460.4)  
R 460.2501, R 460.2503, R 460.2505, R 460.2506, R 460.2509, R 460.2519, R 460.2520,  
R 460.2521, R 460.2522, R 460.2524, R 460.2531, R 460.2532, R 460.2533, R 460.2534,  
R 460.2543, R 460.2545, R 460.2546, R 460.2568, R 460.2568a, R 460.2569a, R 460.2569b,  
R 460.2572, of the Michigan Administrative Code are amended, and R 460.2505a, R 460.2505b,  
R 460.2505c, and R 460.2568b are rescinded to read as follows:  
PART I. GENERAL PROVISIONS  
R 460.2501 Scope.  
Rule 1. (1) These rules apply to all books of account and other records prepared by or on  
behalf of the public utility. See R 460.2582 for records that come into the possession of the public  
utility in connection with the acquisition of property, such as a purchase, consolidation, or merger.  
(2) These rules shall not be construed as excusing compliance with any other lawful  
requirement for the preservation of records for periods longer than those prescribed in these rules.  
When a gas utility collects rates authorized by this commission based on increased supplier rates  
collected under bond under the authority of the Federal Energy Regulatory Commission (FERC),  
this utility shall maintain sufficient gas consumption records to enable the calculation of refunds  
to individual customers as may be ordered by the Michigan public service commission. This  
requirement continues in effect until final action by FERC or until the final decree of the court, if  
appealed to the court, and until the time when the Michigan public service commission has entered  
its order authorizing appropriate refunds if applicable.  
(3) Unless otherwise specified in part 2 of these rules, duplicate copies of records may be  
destroyed at any time if the duplicate copies do not contain significant information not shown on  
the originals.  
(4) Records other than those listed in part 2 of these rules may be destroyed at the option of  
the public utility if records that are used in place of those listed will be preserved for the periods  
prescribed for the records used for substantially similar purposes and if the retention of records  
June 9, 2021  
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pertaining to added services, functions, and plant, the establishment of which cannot be presently  
foreseen, will conform to the principles embodied in these rules.  
(5) Upon written request of a public utility, or on its own motion, the commission may waive  
any requirements of these rules when it determines that the waiver will further the effective and  
efficient administration of these rules and is in the public interest.  
R 460.2503 Protection and storage of records.  
Rule 3. The public utility shall provide reasonable protection for records subject to these rules  
from damage by fires, floods, and other hazards and shall safeguard the records from unnecessary  
exposure to deterioration. The public utility shall also operate a back-up system to preserve  
electronic information and records that are required to be retained under these rules.  
R 460.2505 Preservation of record storage media generally.  
Rule 5. A public utility has the flexibility to select its own storage media, subject to the  
following conditions:  
(a) The storage media selected must have a life expectancy at least equal to the applicable  
record retention period provided in part 2 of these rules unless there is a quality transfer from 1  
media to another with no loss of data.  
(b) A public utility shall implement internal control procedures that ensure the reliability of,  
and ready access to, data stored on machine-readable media. Internal control procedures shall be  
documented by a responsible supervisory official.  
(c) A transfer of data from 1 media to another must be verified for accuracy and documented.  
Software and hardware required to produce readable records shall be retained for the same period  
as the media format is used.  
R 460.2505a Rescinded.  
R 460.2505b Rescinded.  
R 460.2505c Rescinded.  
R 460.2506 Destruction of records.  
Rule 6. At the expiration of the retention period, a public utility may use any appropriate  
method to destroy records as long as the method ensures the full destruction of information  
contained in the documents that is forbidden by law from being divulged to unauthorized persons.  
R 460.2509 Retention periods designated “Destroy at option.”  
Rule 9. Use of the retention period, “Destroy at option,” in these rules authorizes the  
destruction of records at management’s discretion if the destruction of the records does not conflict  
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with other legal retention requirements or usefulness of such records in satisfying pending  
regulatory actions or directives.  
PART 2. SCHEDULE OF RECORDS AND PERIODS OF RETENTION  
R 460.2519 Contracts and agreements; retention periods.  
Rule 19. Except as provided elsewhere in these rules, the following contract and agreement  
records shall be retained for the periods listed:  
(a) Service contracts, such as for  
management, accounting, and financial  
services including related memoranda and  
revisions.  
See R 460.2522(b)(i) if they affect cost of  
plant; otherwise, 6 years after expiration or  
cancellation or until the conclusion of any  
contract disputes or governmental  
proceedings pertaining to these contracts,  
whichever is later.  
(b) Contracts with other utilities for the  
purchase, sale, or interchange of product,  
including related memoranda or revisions.  
6 years after expiration or cancellation or  
until the conclusion of any contract disputes  
or governmental proceedings pertaining to  
these contracts, whichever is later.  
(c) Leases pertaining to rentals of property to  
or from others.  
6 years after expiration or cancellation or  
until the conclusion of any contract disputes  
or governmental proceedings pertaining to  
these contracts, whichever is later.  
(d) Contracts and agreements with individual  
employees, labor unions, company unions,  
and other employee organizations relative to  
wage rates, hours, and similar matters.  
6 years after expiration or cancellation or  
until the conclusion of any contract disputes  
or governmental proceedings pertaining to  
these contracts, whichever is later.  
(e) Contracts, agreements, and other essential  
records necessary to the carrying out of the  
functions of an employee’s stock purchase or  
other type of employees’ saving plan.  
6 years after expiration or cancellation.  
(f) Memoranda essential to clarifying or  
explaining provisions of contracts listed in  
subdivisions (a) to (e) of this rule.  
For same periods as contracts to which  
they relate.  
(g) Card or book records of contracts leases,  
and agreements made, which show dates of  
expirations, dates of renewals, memoranda of  
receipts, and payments under such contracts,  
leases, and agreements.  
For same periods as contracts to which  
they relate.  
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(h) Contracts or agreements for the  
acquisition or disposal of investments,  
excluding temporary cash investments.  
25 years after disposal.  
R 460.2520 General and subsidiary ledgers; retention periods.  
Rule 20. The following ledger records shall be retained for the periods listed:  
(a) General ledgers.  
10 years.  
10 years.  
(b) Ledgers subsidiary or auxiliary to general  
ledgers, except ledgers provided for elsewhere  
in these rules.  
(c) Indexes to general ledgers.  
10 years.  
10 years.  
(d) Indexes to subsidiary ledgers except  
ledgers provided for elsewhere in these rules.  
(e) Trial balance sheets of general and  
subsidiary ledgers.  
2 years.  
R 460.2521 Journals; retention period.  
Rule 21. General and subsidiary journals, including departmental and divisional journals,  
shall be retained for a period of 10 years.  
R 460.2522 Journal vouchers and entries; retention periods.  
Rule 22. The following journal voucher and entry records shall be retained for the periods  
listed:  
(a) General, departmental, divisional, and  
petty journal vouchers.  
25 years.  
(b) Materials and supplies disbursement, labor  
distribution, and other detail summarization  
and distribution records that support journal  
vouchers or journal entries as follows:  
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(i) Charging plant accounts.  
6 years, if accounting adjustments  
resulting from reclassification and original  
cost studies have been approved by the  
regulatory commissions having jurisdiction  
and if continuing plant inventory records are  
maintained or unitization of construction  
costs appear in work orders; otherwise 25  
years. For licensed projects, time tickets, and  
material issued and material returned tickets  
may be destroyed at option if the basic  
information contained in the accounts is  
transcribed to other records and if such other  
records are retained pursuant to this  
instruction. Basic information regarding time  
tickets includes, at a minimum, for the  
purpose of this instruction, hours worked and  
the distribution of time to the proper job or  
account.  
(ii) Charging all other accounts.  
6 years.  
(c) Papers forming part of, or necessary to  
explain, journal vouchers or journal entries,  
except as covered in subdivision (b) of this  
rule.  
25 years.  
(d) Schedules for recurring journal entries.  
(e) Lists of standard journal entry numbers.  
Destroy when superseded.  
Destroy when superseded.  
R 460.2524 Vouchers and voucher registers; retention periods.  
Rule 24. (1) The following voucher records shall be retained for the periods listed:  
(a) Paid and canceled vouchers (1 copy)  
analysis sheets showing detailed distribution  
of charges on individual vouchers and other  
supporting papers.  
6 years, as specified in R 460.2522(b)(i)  
and (ii), except that those relating to the  
construction of licensed projects, additions or  
betterment of those projects, or the  
amortization reserve applicable to those  
projects, for which the commission has not  
determined the actual legitimate original cost,  
shall be retained until such cost has been  
determined.  
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(b) Original bills and invoices for materials  
and services paid by vouchers.  
6 years as specified in R 460.2522(b)(i)  
and (ii), except that those relating to the  
construction of licensed projects, additions or  
betterment of those projects, or the  
amortization reserve applicable to those  
projects, for which the commission has not  
determined the actual legitimate original cost,  
shall be retained until this cost has been  
determined.  
(c) Paid checks and receipts for payments by  
voucher or otherwise.  
6 years.  
(d) Authorization for the payment of specific  
vouchers.  
6 years.  
(e) Lists of unaudited bills (accounts  
payable), lists of vouchers transmitted, and  
memoranda regarding changes in unaudited  
bills.  
Destroy at option.  
(f) Voucher indexes.  
Destroy at option.  
(2) Voucher registers or similar records shall be retained for a period of 6, as specified in R  
460.2522(b)(i) and (ii).  
R 460.2531 Automatic data processing record; retention periods.  
Rule 31. (1) The following automatic data processing records shall be retained for the periods  
listed:  
(a) Media used as intermediate records or  
steps in data processing for assembling data to  
be posted to the records of the company or  
used in a report or study.  
Destroy at option.  
(b) Program documentation and revisions to  
this documentation.  
Retain as long as it represents an active  
viable program or for periods prescribed for  
related output data, whichever is shorter.  
(2) Original source data used as input for data processing and data processing report printouts  
shall be retained for the applicable periods prescribed elsewhere in the schedule.  
R 460.2532 Plant ledgers; retention periods.  
Rule 32. The following plant ledgers and records shall be retained for the periods listed:  
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(a) Ledgers of utility plant accounts,  
25 years.  
including land and other detailed ledgers that  
show the cost of utility plant by classes.  
(b) Continuing plant inventory ledger, book,  
or card records that show the description,  
location, quantity cost, and similar  
information of physical units, or items, of  
utility plant owned.  
25 years after the plant is retired if  
mortality data are retained. For depreciation  
purposes, life or mortality study data shall be  
retained for the life of the corporation.  
R 460.2533 Construction ledgers, work orders, and supplemental records; retention periods.  
Rule 33. The following construction work in progress ledgers, work orders, and supplemental  
records shall be retained for the periods listed:  
(a) Construction work in progress ledgers.  
5 years after clearance to the plant  
account if continuing plant inventory records  
are maintained; otherwise, 5 years after the  
plant is retired.  
(b) Work order sheets that show entries for  
labor, materials, and other charges for utility  
plant additions, and entries closing the work  
orders for utility plant in service at  
completion.  
5 years after clearance to the plant  
account if continuing plant inventory records  
are maintained; otherwise, 5 years after the  
plant is retired.  
(c) Authorizations for expenditures for  
additions to utility plant, including  
memoranda that show the detailed estimates  
of cost and the basis for that estimated cost.  
Original and revised or subsequent  
authorizations shall be included.  
5 years.  
(d) Requisitions and registers of  
authorizations for utility plant expenditures.  
5 years.  
5 years.  
(e) Completion or performance reports that  
show the comparison between authorized  
estimates and actual expenditures for utility  
plant additions.  
(f) Analysis or cost reports that show  
quantities of materials used, unit costs,  
number of man-hours, and similar  
information in connection with completed  
construction projects.  
5 years after clearance to the plant  
account if continuing plant inventory records  
are maintained; otherwise, 6 years after the  
plant is retired.  
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(g) Records and reports that pertain to the  
progress of construction work, the order in  
which jobs are to be completed, and similar  
records that do not form a basis of entries to  
the accounts.  
Destroy at option.  
(h) Records of gas acreage owned, leased, or  
1 year after the facility or relevant  
optioned; lease records; well-drilling logs and production area is abandoned.  
well-construction records; and geological and  
photographic maps of field.  
R 460.2534 Retirement ledgers, work orders, and supplemental records; retention periods.  
Rule 34. The following retirement work in progress ledgers, work orders, and supplemental  
records shall be retained for the periods listed:  
(a) Work order sheets that have the entries for  
removal costs, materials recovered, and  
credits to utility plant accounts for cost of  
plant retired posted to them.  
5 years after the plant is retired if  
mortality data are retained.  
(b) Authorization for retirement of utility  
plant, including memoranda that show the  
5 years after clearance to the plant  
account if continuing plant inventory records  
basis for the determination of the cost of plant are maintained; otherwise, 5 years after the  
to be retired and estimates of salvage and  
removal costs.  
plant is retired, if mortality data are retained.  
(c) Registers of retirement work orders.  
5 years.  
R 460.2543 Deposit records; retention periods.  
Rule 43. The following deposit records shall be retained for the periods listed:  
(a) Bank deposit books.  
1 year.  
(b) Copies of bank deposit slips.  
1 year.  
(c) Advice of deposits made when  
information about the deposits is shown on  
other records that are retained.  
Destroy at option.  
(d) Statements from depositories that show  
the details of funds received, disbursed, and  
transferred and balances on deposits.  
Destroy at option.  
(e) Bank reconcilement papers.  
1 year.  
1 year.  
(f) Statements from banks of interest credits.  
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(g) Check stubs, registers, or other records of  
checks issued.  
3 years.  
(h) Correspondence and memoranda that  
relate to the stopping of payment of bank  
checks and to the issuance of duplicate  
checks.  
3 years or destroy at option after recovery  
of the check(s).  
R 460.2545 Customer service applications and contracts; retention periods.  
Rule 45. The following customer service applications and contracts shall be retained for the  
periods listed:  
(a) Applications for utility service for which  
contracts have been executed.  
Destroy at option.  
1 year.  
(b) Applications for utility service used in  
place of contracts.  
(c) Contracts and card files, or other records  
thereof, with customers for utility service.  
1 year after expiration or cancellation. If  
the contracts are with other utilities for the  
purchase, sale or interchange of product, R  
460.2519(b) applies.  
(d) Applications for utility service that were  
withdrawn by the applicant or not granted by  
the utility.  
1 year.  
(e) Contracts or sales agreements with  
customers and others for the sale of  
merchandise and appliances.  
1 year after sales agreement is discharged.  
(f) Contracts for the lease of equipment to  
customers, including receipts for this  
equipment.  
1 year after expiration of contract or  
return of equipment.  
(g) Applications and contracts for extensions  
covered by refundable deposits or guarantees  
of revenue and records that pertain to such  
contracts.  
1 year after entire amount is refunded.  
6 years after expiration.  
(h) Applications and contracts for extensions  
for which donations or contributions are made  
by customers or other individuals.  
R 460.2546 Rate schedules; retention periods.  
Rule 46. The following rate schedule records shall be retained for the periods listed:  
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(a) General files of published rate sheets and  
schedules of utility service, including  
schedules suspended or superseded.  
6 years.  
(b) Regional or local office copies of rate  
sheets and schedules of utility service.  
1 year after expiration or cancellation.  
R 460.2568 Electricity production records; retention periods.  
Rule 68. The following electricity production records shall be retained for the periods listed:  
(a) Boiler room, condenser room, turbine  
room, and pump room logs, including  
supporting data.  
3 years.  
3 years.  
(b) Boiler room and turbine room reports of  
equipment in service and performance.  
(c) Boiler-tube failure report.  
3 years.  
3 years.  
(d) Generation and output logs with  
supporting data.  
(e) Station and system generation reports.  
25 years, except that those relating to  
licensed projects, or additions or betterments  
to those projects, for which the commission  
has not determined the actual legitimate  
original cost, shall be retained 25 years and  
until this cost has been determined.  
(f) Generating high-tension and low-tension  
load records.  
3 years.  
(g) Oil and waste reports.  
3 years.  
3 years.  
(h) Load curves, temperature logs, and coal  
and water logs.  
(i) Gage reading reports.  
2 years, except that river-flow data  
collected in connection with hydro-operation  
shall be retained for the life of the  
corporation.  
(j) Recording instrument charts.  
1 year, except that where the basic chart  
information is transferred to another record,  
the charts shall be retained for only 6 months  
if the record that contains the basic data is  
retained for 1 year.  
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(k) Load dispatcher’s and station permits.  
1 year, except that where the basic chart  
information is transferred to another record,  
the charts shall be retained for only 6 months  
if the record that contains the basic data is  
retained for 1 year.  
R 460.2568a Manufactured Gas Plant Site records; retention periods.  
Rule 68a. Manufactured gas plant site records shall be retained for a minimum of 10 years  
past an Environmental Protection Agency (EPA) or Michigan Department of Environment, Great  
Lakes, and Energy (EGLE) approval of the completed remediation or 10 years after the final  
remediation amounts have been approved by the commission, whichever is longer. The company  
shall offer to submit technical documents supporting the remedial activities to the commission  
before their destruction.  
R 460.2568b Rescinded.  
R 460.2569a Gas transmission and distribution records; retention periods.  
Rule 69a. The following gas transmission and distribution records shall be retained for the  
periods listed:  
(a) Transmission line logs.  
If records are not disputed or adjusted,  
destroy after 1 year.  
(b) Transmission and distribution department  
load dispatching operating logs.  
If records are not disputed or adjusted,  
destroy after 1 year.  
(c) Service interruption logs and reports.  
6 years.  
3 years.  
(d) Records of general inspections and  
operating tests.  
(e) Reports on inspections and repairs of all  
street openings.  
6 years.  
(f) Apparatus failure reports.  
(g) Records of meter tests.  
6 years.  
Until superseding test, but not less than 2  
years or as may be necessary to comply with  
service rules regarding refunds on fast meters.  
(h) Meter history records.  
For the life of the meter.  
3 years.  
(i) Meter shop reports that are monthly reports  
summarizing tests and repairs.  
(j) Gas measuring records.  
1 year, unless measurement data have  
been disputed or adjusted.  
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(k) Transmission line operating reports.  
(l) Compressor operation and reports.  
(m) Gas pressure department reports.  
(n) Recording instrument charts, such as  
1 year, unless measurement data have  
been disputed or adjusted.  
1 year, unless measurement data have  
been disputed or adjusted.  
1 year, unless measurement data have  
been disputed or adjusted.  
1 year, unless measurement data have  
pressure (static and differential), temperature, been disputed or adjusted; except that where  
specific gravity, and heating value.  
charts are exchanged with the customer and  
the basic information is transferred to another  
record, the charts shall be retained for only 6  
months if the record that contains the basic  
chart data is retained for 1 year.  
R 460.2569b Underground storage of natural gas.  
Rule 69b. The following underground storage of natural gas records shall be retained for the  
time periods listed:  
(a) Well records, reports, and logs that include  
data relating to pressures, injected volumes,  
withdrawn volumes, core analysis, daily  
volumes of gas injected into and withdrawn  
from reservoir, cushion, and working gas  
volumes for each reservoir.  
1 year after reservoir, field, or relevant  
storage area is abandoned.  
(b) Records containing information relating to  
reservoir gas leakage, showing the total gas  
leakage, and recycled gas.  
1 year after reservoir, field, or relevant  
storage area is abandoned.  
(c) Records on back pressure tests field data.  
1 year or until superseded.  
1 year or until superseded.  
(d) Records on back pressure test results, gas  
analysis.  
R 460.2572 Statistics; retention periods.  
Rule 72. The following statistical records shall be retained for the periods listed:  
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(a) Annual financial, operating, and statistical  
reports regularly prepared in the course of  
business for internal administrative or  
5 years after date of report.  
operating purposes (and not used as the basis  
for entries to the accounts of the companies  
concerned) to show the results of operations  
and the financial condition of the utility.  
(b) Quarterly, monthly, or other periodic  
financial, operating, and other statistical  
reports as described in subdivision (a)of this  
rule.  
2 years.  
(c) All other statistical reports not covered  
elsewhere in these rules that are prepared for  
internal administrative or operating purposes  
only and that are not used as the basis for  
entries to the accounts of the company.  
Destroy at option.  
(d) Summaries of expenditures on  
maintenance and job orders and clearance to  
operating and other accounts, exclusive of  
plant accounts.  
6 years.  
;