Schedule No. 60 Infrastructure Records

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Issued: July 2012

Updated: July 19, 2017

General Description: Records pertaining to basic infrastructure and underlying public works services and systems.

No record may be destroyed under this General Retention Schedule without the approval from the Records Department and the City and County of Denver’s Records Manager. Additionally, no record may be destroyed if the record is subject to an active litigation hold (refer to Executive Order 143-C). For additional information about the records program or records retention refer to Executive Order 143-B. The Records Management Program Policies and Procedures Manual for instruction about records creation, management, and disposition of individual records. The minimum retention periods specified in this schedule apply to the information contained within the record, regardless of the format of the record (paper, microfilm, electronic, etc.). Each agency must decide on the format for retention of each type of record, ensuring authenticity, readability, and accessibility for the entire retention period. Duplicate copies are NOT records. Copies that are created for administrative, convenience, reference or other purpose are NOT records and should be retained only until no longer useful. Electronic Records and Data must remain accessible, authentic, reliable, and usable through any kind of system change, update, or system end of life for the entire period of its retention, which shall be defined by information-type, as presented in this General Retention Schedule. Provided the data is an accurate representation of the information contained in the source documents from which the data was derived, the source documents need not be retained unless they contain other record information not contained in the electronic repository.

60.010 ELECTRIC SERVICE

Records relating to the provision of electric service. Note: NERC refers to the North American Electric Reliability Council.

  1. Critical Asset Records
    Lists of identified critical assets and documentation of the risk-based assessment methodology used to determine critical assets.

    Retention:
    2 years, in addition to records of last audit[NERC CIP-002-3]

  2. Dispatch and Scheduling Records
    1. Daily Dispatch Logs
      Retention: 3 years [NERC IRO-004-2]
    2. Disturbance Records
      Records relating to outages, surges, etc.
      1. Disturbance Data and Audits
        Retention:
        3 years[NERC PRC-018-1]

      2. Final Disturbance Report
        Retention:
        7 years, then evaluate for continuing value
    3. Operating Procedures
      Written operating procedures for real-time actions to be taken during normal and emergency conditions to ensure stable and reliable operation of bulk electric system.

      Retention:
      Permanent [NERC PER-001-0.1]

    4. Special or Periodic Reports and Risk Assessment on Service Interruptions
      Retention:
      3 years [NERC IRO-004-2]

    5. System Operating Logs
      Retention:
      3 years [NERC IRO-004-2]
  3. Energy Efficiency Program Records
    Records relating to services provided to customers under energy efficiency or conservation programs; includes applications, agreements, review reports, correspondence, data collection records, spreadsheets, etc.

    Retention:
    4 years after expiration [18 CFR 125.3.29]

  4. Engineering Records and Supporting Documentation
    Final as-built drawings, system schematics, shop drawings, diagrams showing layouts, designs, plans, patterns and configuration for systems and equipment; engineering studies, plans and reports; maps, diagrams, profiles, photographs, drawings and supporting documentation showing locations of utility production, transmission and distribution facilities as constructed or as proposed; soil condition reports; survey field books documenting survey methodologies and activities; topographic surveys; and similar records.

    Retention:
    Life of facility [18 CFR 125.2,18 CFR 125.3.21]

  5. Maintenance Work Orders
    Cost estimates, work order sheets, summaries of expenditures on maintenance, job orders and clearances.

    Retention:
    5 years [18 CFR 125.3.15]

  6. Power System Accounting and Billing Records
    1. Deviation Reports– Summaries of System Changes
      Retention:
      3 years [NERC IRO-004-2]

    2. OASIS (Open Access Same-Time Information System)Records
      1. Audit Data
        Data relating to OASIS postings for available transmission capability (ATC) and total transmission capability (TTC), agreed-upon transmission service transactions, agreed-upon ancillary service transactions, denied requests for transmission service and curtailed or interrupted transactions.

        Retention:
        Must be made publicly available upon request for download for 5 years from date posted, in same electronic form used when originally posted on OASIS [18 CFR 37.7(b)]

      2. Data Used to Calculate ATC and TTC
        Calculated for any constrained posted paths, including limiting element(s) and the cause of the limit; e.g., thermal, voltage, stability.

        Retention:
        6 months [18 CFR 37.6(b)(2)(ii), NERC IRO-004-2]
    3. Surplus Sales Records

      Retention:
      3 years [NERC IRO-004-2]

    4. System Control and Data Acquisition (SCADA) Records
      1. Data – Hourly and One-Minute
      2. Retention: 4 months
      3. Disturbance Records – Outages, Surges,etc.
        1. Final Disturbance Reports
          Retention:
          7 years, then evaluate for continuing value
        2. Preliminary Information
          Request forms, notifications, investigations, preliminary disturbance reports, etc.
          Retention: Until final disturbance report is completed
        3. System Disturbance History (Summary)
          Retention:
          Permanent
  7. Production Records
    1. Boiler Tube Failure Report
      Retention:
      3 years[18 CFR 125.3 13.1(a)]
    2. Gauge Reading Reports
      Retention:
      2 years[18 CFR 125.3 13.1(f)]
    3. Generation and Output Logs and Supporting Data
      Retention:
      3 years[18 CFR 125.3 13.1(b)]
    4. Generating High-Tension and Low-Tension Load Records
      Retention:
      3 years[18 CFR 125.3 13.1(d)]
    5. Load Curves, Temperature Logs, Coal and Water logs
      Retention:
      3 years [18 CFR 125.3 13.1(d)(e), NERC IRO-004-2]
    6. Recording Implementation Charts
      Retention:
      1 year [18 CFR 125.3 13.1(g)]
    7. Station and System Generation Reports and Clearance Logs (Steam and Other)
      Retention:
      6 years[18 CFR 125.3 13.1(c)]
  8. Regulatory Reports
    Reports to federal and state regulatory commissions, including annual financial, operating, and statistical reports.

    Retention:
    5 years[18 CFR 125.3 41]

  9. System Planning Records
    1. Emergency Operations Plans and Supporting Documentation
      Emergency load reduction plans and other plans to address insufficient generating capacity, transmission system, load shedding, system restoration, mitigation of operating emergencies, training programs, restoration plans, testing of communications and other aspects of the plans, verification results for the current approved restoration plan, implementation strategies for disturbances, re-synchronization data, records of participation in all requested drills, exercises or simulations, back start resource agreements, etc.

      Retention:
      3 years and until completion of compliance audit[NERC EOP-001-2, NERC EOP005-2]

    2. Reliability Impact Assessments, System Studies and Supporting Documentation
      System studies and assessments of new facilities and connections on the interconnected transmission systems (potential interface and other operating limits; i.e., overloaded transmission lines and transformers, voltage and stability limits) ensuring that bulk electric system can be operated reliably in anticipated normal and contingency event conditions; data needed for system studies and reliability assessments; critical facility status, load, generation, operating reserve projections, known interchange transactions, transmission data, generation data, balancing authority demand, area control error and frequency, etc.; action plans for reconfiguration of transmission system, re-dispatching of generation, reduction or curtailment of interchange transactions reducing load to return transmission loading to acceptable sols or irols.

      Retention:
      3 years [NERC IRO-004-2, NERC FAC-002-1]

    3. System Planning Studies
      Specific network impact studies performed for customers, includes listings of system planning studies posed on OASIS.

      Retention:
      5 years [18 CFR 37.6(b)(2)(iii), NERC FAC-002-1]
  10. Transmission and Distribution Records
    Substation and transmission equipment and operation records, including maintenance, operation, inspection and testing records for substations and the transmission system.
    1. Equipment History Records
      Maintenance histories, operation, inspection and testing records for batteries, gas breakers, hot sticks and grounds, insulators, oil breakers, relays and similar equipment; includes transformer inspections, oil tests, etc.

      Retention:
      5 years
    2. Exception Reports
      Apparatus failure reports, interruption logs and reports, transmission line trouble reports, etc.

      Retention:
      6 years

    3. Lightning and Storm Data

      Retention:
      Until no longer needed for reference

    4. Meter Change-Out Reports
      Received from substation crews when they work on meters.

      Retention:
      3 years [NERC FAC-002-1, NERC IRO-004-2, NERC PRC-005-1]

    5. PCB Transformer Records
      1. PCB Disposal Logs
        Retention:
        At least 3 years after facility ceases using or storing PCBs [40 CFR 761.180]
      2. PCB Spill Cleanup and Decontamination Records
        Retention:
        5 years [40 CFR 761.125(b)(3)]
      3. PCB Transformer Inspection and Maintenance History
        Retention: 3 years after disposal [40 CFR 761.30(a)(1)(xii)]
    6. Pole Tower and Transformer History Records

      Retention:
      Life of pole, tower or transformer [Transformers: 18 CFR 125.2 14(c)]

    7. Relay Settings for Substations
      Documentation of types, settings, input and output, substation location, etc.

      Retention:
      Until superseded

    8. Substation and Transmission Line Logs

      Retention:
      3 years[18 CFR 125.3 14(a)]

    9. Substation Compliance Reports
      Annual NERC reports– general inspection and operating tests.

      Retention:
      3 years

    10. Switching Records (Substation

      Retention:
      3 years [NERC IRO-004-2]

    11. System Operator's Daily Logs and Reports of Operation

      Retention:
      3 years[18 CFR 125.3 14(b)]

    12. Vegetation Management Records
      Quarterly program reports and tree trimming around transmission lines and substations.

      Retention:
      5 years [NERC FAC-003-1]

60.020 LOCATE REQUESTS

Records of utility and infrastructure locate requests.

Retention: 90 days after locating is completed or determined to be responsibility of another jurisdiction

60.030 SOLID WASTE MANAGEMENT

Records pertaining to landfills, recycling centers and solid waste management.

  1. Dump or Trip Tickets
    Receipts for loads hauled to landfills or recycling centers.
    Retention:
    3 years

  2. Landfill Locations
    Records documenting the locations of current and past landfills and dumps.
    Retention:
    Permanent

  3. Landfill and Recycling Operations [Reserved]

60.40 STORM-WATER DRAINAGE SYSTEM RECORDS

Records relating to the management of storm water run-off and drainage, flooding and storm drainage basins.

  1. Basin, Floodplain, Flood-way and Flooding Records
    Records documenting the existence of designated and recognized storm water basins and floodplains, including maps and drawings depicting locations, FEMA flood insurance rate maps and records documenting the locations, extent and levels of flooding and mitigation efforts.

    Retention:
    Permanent

  2. Weather Observation Records
    Data and reports relating to weather conditions impacting the storm water system.

    Retention: Permanent for compilations and 5 years for raw data

  3. Wetlands Management
    Records relating to protection and management of wetlands on Denver property or rights-of- way.

    Retention:
    Permanent for preserved wetlands or 30 years after removal and fill

60.41* Elevation Certificate

Records documenting new buildings and substantial improvements in all identified Special Flood Hazard Areas (SFHAs) are properly elevated. [NFIP 60.3 (b)(5), Community Rating System 114 & 310]

Retention: Permanent

60.42* FLOODPLAIN PERMIT

See Sewer Use and Drainage Permit (SUDP)

60.50 STREET AND TRAFFIC OPERATIONS RECORDS

Records documenting the ongoing street system and traffic flow operations.

  1. Asphalt Testing Records
    Records relating to asphalt testing; may include asphalt sample sand analytical reports.

    Retention: 5 years
  2. Bridge Inspections and Maintenance
    Records of bridge inspections, inventory, changes to bridges, maintenance, and summary reports to the State or other agencies. [23 CFR 650.305, 23 CFR 650.311]

    Retention:
    2 years after bridge is removed from service

  3. Event Records – Traffic Impacts
    Records documenting preparation for and implementation of traffic changes related to special events such as parades, motorcades and demonstrations, including street closures, traffic rerouting, barricades, signal timing changes and other similar variations.

    Retention:
    2 years after event

  4. High Accident Locations
    Records documenting accidents at locations that have a relatively high accident rate.

    Retention:
    6 years

  5. Naming and Renaming of Streets
    Records relating to naming and changes of names of streets and roadways.

    Retention:
    Permanent

  6. Street Address Number Records
    Records pertaining to street closings, assignment and alteration of street names and house numbers, and similar records providing official control of the naming and numbering of streets and addresses.

    Retention:
    Permanent

  7. Street Cleaning and Sweeping Records

    Retention:
    3 years

  8. Street Engineering Records
    Records documenting the layout and planning of streets, intersections and sidewalks, establishment of grades, street and intersection design and alignment, benchmarks and documentation, street and drainage problem histories and similar records of long-term significance.

    Retention:
    Permanent

  9. Street System Records
    Documentation filed on or before December 31, 1953, with the State department of transportation certifying the total mileage of streets in the street system, certification of adoption and a map of the arterial street system, and documentation of subsequent changes in total mileage and arterial mileage shown in an annual report. [CRS 43-2-125 and 43-2-132]

    Retention:
    Permanent

  10. Traffic Congestion Monitoring Records
    Records relating to scheduled or random traffic counts and traffic congestion monitoring, including automated or manual traffic counts.

    Retention:
    6 years

  11. Traffic Marking, Timing and Signalization Files
    Records and data documenting traffic signal timing, traffic marking and signalization and construction zone, crosswalk parking and no parking zones, speed zone and truck route designations.

    Retention:
    2 years after superseded

  12. Weather Observation Records
    Data and reports relating to weather conditions impacting street and traffic operations.

    Retention:
    Permanent for compilations and 5 years for raw data

60.51 Snow Removal [Reference: County Schedule 10.190]

Records relating to the designation of snow routes, snow removal policies, and snow and ice removal programs.

Retention: 2 years after superseded

60.52 State Highway System Records [Reference: County Schedule 10.170]

Records regarding street maintenance contract with Colorado Department of Transportation and other standards and policy issues relating to State highways within the district.

Retention: Permanent

60.53 Street Lighting Files [Reference: County Schedule 10.190]

Records relating to street lighting improvements, maintenance and repairs on district streets and roadways.

Retention: 6 years

60.060 TRANSPORTATION SYSTEM RECORDS

  1. Airport and Airline Operations Records [Reserved]
  2. Railroad Systems Records
    Records pertaining to railroad systems, routes, regulations, and rights-of-way.

    Retention:
    Permanent

  3. Transportation Services Records
    Records pertaining to the overall operation of transportation systems that serve residents, such as light rail, taxicab service, bus system and para-transit service; includes Denver approvals for PUC licenses, route maps and similar records relating to the operation of the service.

    Retention: 6 years

60.070 VACATIONS – STREET, ALLEY AND RIGHT-OF-WAY

Records pertaining to the formal abandonment or vacation of previously dedicated streets, alleys and public rights-of-way or easements.

Retention: Permanent

60.80 WATER AND SEWER DISTRIBUTION AND STORAGE SYSTEM RECORDS

Records relating to the operation of the water and sewer distribution and storage systems.

  1. Cross - Connection Control Survey Records
    Documentation of monitoring of potential or actual water system health hazards from pollution entering water pipes from other pipes, including address, description of protection, corrections made, etc.

    Retention:
    1 year after disconnection or 10 years, whichever is later

  2. Sewer Inspection and Testing Records
    Records of inspections and testing to locate problems and defects so that corrective measures can be taken.
    1. Sewer Test Records
      Documentation of smoke, X-ray and other tests undertaken to verify hookup to main sewer lines, check condition of pipes or determine effectiveness of back flow prevention devices.

      Retention:
      5 years after completion of test

    2. Video Inspection Records
      Records of video inspections to locate problems and defects so that corrective measures can be taken.

      Retention:
      Until after next video inspection, then evaluate prior to destruction of records to determine ongoing value
  3. Tap Permits and Connection Records
    Records regarding the application for and issuance of water and sewer tap permits and connections between specific properties and the utility systems, including those for inside and outside users.

    Retention:
    2 years after disconnection, provided that record of disconnection is retained permanently

  4. Valve Records
    Records documenting installation, locations, and maintenance of valves in the water and sewer systems.
    1. Locations
      Retention:
      Permanent
    2. Maintenance and Repair
      Retention:
      2 years
    3. Specifications
      Retention:
      Until valve is permanently removed from service
  5. Water Consumption Reports
    Compilations of statistics documenting daily water consumption.
    1. Annual Reports
      Retention:
      Permanent
    2. Information Summarized in Annual Reports
      Retention:
      2 years
  6. Water Distribution and Production System Records
    1. Analysis of System
      Retention: 3 years

    2. Reports – Distribution and Production Systems
      Retention: Permanent

    3. Water Line Maintenance and Repair Records
      Documentation of maintenance and repair of water lines.
      1. Records Requiring Engineering Stamp
        Retention:
        2 years after water line permanently removed from service
      2. Other Records
        Retention:
        2 years
    4. Water Pressure Measurements
      Retention:
      6 years

    5. Water Storage Inspection Reports
      Retention: 6 years
    6. Water System Inspection and Testing Records
      1. Video Inspection Records
        Records of video inspections to locate problems and defects so that corrective measures can be taken.
        Retention:
        Until after next video inspection, then evaluate prior to destruction of records to determine ongoing value

      2. Water System Test Records
        Documentation of tests undertaken to verify connections, check condition of pipes, etc.

        Retention:
        5 years after completion of test
    7. Water Use Restriction and Conservation Records
      1. Notices of Restrictions
        Notices of water use restrictions imposed because of restrictions on water supply.
        Retention:
        2 years

      2. Variance Records
        Records of variances for individual property owners to the watering restrictions.
        Retention:
        Until expiration of variance

      3. Water Conservation Records
        Records of activities that promote and coordinate the efficient use of water resources, i.e., educational and outreach efforts, reports, etc.
        Retention:
        5 years, then evaluate for continuing value prior to destruction of records

      60.81* SEWER USE AND DRAINAGE PERMIT (SUDP)

      1. SUDP without Floodplain Permit

        Retention:
        Until Sewer is abandoned or removed

      2. SUDP with Floodplain Permit
        Records related to any use of the floodplain including, but not limited to: application, plans, reports, studies, maps, inspections, correspondence, and permit documents.

        Retention:
        Permanent

      Disconnection Records [Reference: County Schedule 10.250]

      Records documenting the disconnection of properties from district water, sewer, power or similar utility systems.

      Retention: Permanent

      60.83* STORM OR SANITARY ACCOUNT ADJUSTMENTS

      Records explaining how storm or sanitary billing is determined for each account, including answers to customer questions on billing.

      Retention: 5 years; Special accounts with unusual circumstances may require longer retention for administrative purposes.

      60.090 WATER AND SEWER TREATMENT SYSTEM RECORDS

      Records relating to the treatment of water or sewage.

      1. Analytical Reports
        Records relating to analysis of samples taken from various locations throughout the system and from raw and processed sources of supply.
        1. Bacteriological and Microbiological Analysis
          Samples collected for laboratory testing for various contaminants that are naturally present in the environment; includes sewage plant composite sampling records, weekly sewage tests, etc.

          Retention:
          5 years [40 CFR 141.33]

        2. Chemical and Radiological Analysis
          Verification of water quality at various sampling points to determine the presence of chemicals and radionuclides from the decay of natural and man-made deposits and the erosion of natural deposits.

          Retention:
          10 years [40 CFR 141.33]

        3. Lead and Copper Analysis
          Tests to determine the levels of lead and copper resulting from the corrosion of household plumbing systems, the erosion of natural deposits and leaching from wood preservatives; includes sampling data and analyses, reports, surveys, letters, evaluations, schedules, state determinations, etc.

          Retention:
          12 years [40 CFR 141.91]

        4. Secondary Contaminants Analysis
          Tests to determine the levels of inorganic and volatile organic contaminants.

          Retention:
          10 years [40 CFR 141.33]

        5. Turbidity Analysis
          Documentation of analysis of water samples to determine level of cloudiness caused by suspended particles resulting from soil runoff.

          Retention:
          5 years [40 CFR 141.33]

        6. Water Test Standards
          Standards for water testing.

          Retention: 5 years after superseded
      2. Annual Reports
        Reports created on annual basis, including national primary drinking water consumer confidence reports delivered to consumers, documenting water and wastewater treatment operations.

        Retention:
        Permanent

      3. Corrective Actions– Noncompliance
        Documentation of actions to correct violations of primary drinking water regulations. Retention: 3 years after last action regarding violation [40 CFR 141.33]

      4. Discharge Permits and Monitoring
        Documentation of pollution and effluent discharged from wastewater treatment facilities and reports submitted in conjunction with permit compliance; permits issued under the Clean Water Act by the Colorado Department of Health or Environmental Protection Agency/ National Pollution Discharge Elimination System (NPDES) for discharge of treated sewage under controlled conditions.

        1. Inspection Records
          Documentation of annual inspections of wastewater treatment operations to monitor compliance with NPDES permit conditions. Retention: 5 years

        2. Odor Complaints
          Retention:
          3 years

        3. Permits and Supporting Documentation
          Retention: 5 years after expiration, cancellation, revocation, or denial
      5. Industrial Pretreatment Permits
        Permits and permit modifications issued to private industries allowing the discharge of specific pollutants under controlled conditions.

        Retention:
        5 years after expiration, cancellation, revocation, or denial

      6. Operational Reports
        1. Chlorination Reports
          Retention:
          10 years

        2. Filter Plant Logs
          Daily information regarding plant operations.
          Retention: 5 years

        3. Plant Capacity Records
          Retention:
          2 years

        4. Sand Trap Inspections
          Retention:
          Life of sand trap
      7. Sanitary Surveys of System
        Studies, surveys or reports examining the overall sanitary condition of water and wastewater systems and any communications regarding the sanitary survey.

        Retention:
        10 years after completion of sanitary survey [40 CFR 141.33]

      8. Sludge Application Records
        Documentation of placement of approved sites and the surface application of sewage sludge to approved sites.
        1. Domestic Septage Application
          Retention:
          5 years [40 CFR 503.17]

        2. Permits and Supporting Documentation
          Retention:
          5 years after expiration, cancellation, revocation, or denial

        3. Preparation and Application of Sludge
          Records relating to preparation of sewage sludge and the application of sewage sludge to approved sites, including certifications of concentration of pollutants, pathogen requirements and management practices.
          Retention:
          5 years [40 CFR 503.17]

        4. Surface Disposal Site Placement
          Records of sewage sludge placed on surface disposal sites, including name and address of persons who prepare the sludge, name and address of the landowner or lease holder, site location, an explanation of why the sludge must remain on the site for longer than two years before final use or disposal, and an estimate of when final disposal will take place.

          Retention:
          By person who prepares sludge, for as long as sewage sludge remains on land [40 CFR 503.20]
      9. Variances and Exemptions
        Retention:
        5 years after expiration [40 CFR 141.33]

      60.100 WATER SOURCE OF SUPPLY RECORDS

      Records pertaining to source of supply of raw (untreated) water, including records relating to adjudication, acquisition, dedication and transfer of water shares and water resources and records relating to the water storage system. [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in electronic format.]

      1. Acquisition, Sale and Transfer Records
        Records relating to acquisition, sale, or transfer of water rights, including water acquisition agreements, dedication of water rights by developers to meet development requirements, court proceedings, water decrees, allotment contracts, temporary use permits and other similar transactions.

        Retention:
        Permanent, except that water offers are to be retained until accepted or rejected [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in paper format.]

      2. Dam Monitoring and Inspection Records
        Dam safety inspections and monitoring data and reports.

        Retention:
        Life of dam + 1 year

      3. Ditch Records
        Records relating to gauging station and visual monitoring of ditch flows and conditions.

        Retention: Life of ditch + 1 year

      4. River and Stream Records
        1. Flow Measurements
          Data reported to the State Engineer's Office regarding water flows, collected from recording stations in streams or wells.

          Retention:
          1 year

        2. Hydrologic Data – Rivers and Streams
          Raw data collected from field gauging stations established to monitor diverted river and stream flows.

          Retention:
          5 years, provided that data is compiled into report that is retained permanently

        3. Surface Water Rights Records
          Augmentation plans, river flow observations, adjudication of priorities of use and similar records relating to surface water rights.

          Retention:
          Permanent [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in paper format.]
      5. Underground Water Rights and Supply
        Records relating to underground aquifers, water wells and similar records.

        Retention:
        Permanent [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in paper format.]

      6. Water Decree Accounting Records retained as required by the State Engineer or Water Court to track the use of water under a decree.

        Retention:
        Permanent [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in paper format.]

      7. Water Rental or Leasing Records
        Records relating to water stock assessments and seasonal rental of surplus irrigation water.

        Retention:
        6 years

      8. Water Stock Certificates
        Documents issued by water companies as proof of an ownership interest in the company.

        Retention: Until sale or transfer of stock

      9. Weather Records
        1. Weather Modification Records
          Records of cloud seeding projects.

          Retention: Permanent

        2. Weather Observation Records
          Reports on weather, river, snow pack and climatological observations affecting water supply.

          Retention: Permanent for data compilations and 5 years for raw data
      10. Well Records
        Records pertaining to location, adjudication, permit applications, drilling, installation, testing, use and abandonment of water wells for Denver use.

        Retention:
        Permanent [Important Note: Water rights records are considered to be essential records to Denver, and it is therefore recommended that the "record" copy be retained in paper format.]

      60.101 Weather Sensor Calibration and Testing Records [Reference: County Schedule 10.310 Weather Records]

      Documentation of testing and calibration of district weather sensors to ensure accuracy

      Retention: Life of equipment + 1 year

      60.102 Water Modeling and Forecasting Records [Reference: County Schedule.310]

      Records relating to projections of future water needs and supplies for the county.

      Retention: Permanent

      Cross References

      Agreements and contracts– 40.030*, Agreements and Contracts Annexation review records – 65.010, Annexation Case Files

      Communication infrastructure – Schedule 55, Information Technology and Communication Systems Records Communication systems franchises – 30.110, Franchise Records

      Complaints – 40.090, Complaints, Routine Service Requests and Nonbinding Petitions Correspondence – Schedule 145, Correspondence Records

      Development review records – 65.030*,Development Case Files

      Easements – 95.030, Easements and Rights-of-Way and Supporting Documentation Emergency plans – 100.040, Emergency Planning and Response

      Encroachments – 75.020*.G, Permits to Work in Public Way

      Enterprise board records – 45.060, Governing Body as Another Decision-Making Body Equipment calibration, maintenance, and testing– 35.010*, Equipment Records in General Fee collection – 30.020*, Accounts Receivable (A/R) Records

      Franchises – 30.110, Franchise Records

      Hazardous waste – 25.020*, Hazardous Waste Storage and Transport Records Impact fees – 30.020*, Accounts Receivable (A/R) Records

      Improvement districts – 30.130, Improvement District Records Landfill monitoring – 25.010*, Environmental Monitoring and Reviews

      Maps and drawings – 40.180, Maps, Drawings and Supporting Documentation

      Metering records– 30.210.B, Meter Records Plans – 40.330,Studies, Plans and Reports Policies and procedures – 40.220*, Policies and Procedures Documentation

      Projects – 40.240*, Non O&M Project Files

      Rebate programs – 30.180*, Rebate Program Records Reports – 40.290, Reports

      Rules, regulations, and standards – 40.310, Rules, Regulations and Standards Studies – 40.330, Studies, Plans and Reports

      Traffic code – 40.070.A,Codes Adopted by Reference

      Training and operator records– 90.070*, Employee Records – Active and Terminated Utility billing – 30.210, Utility

      Billing Water and sanitation district records – 40.320, Special District Records