Storage Tank Comprehensive Inspections

We hope 2022 is off to a good start for you! Do you have storage tanks in the distribution system (after the Entry Point sampling location) and when was the last time the tanks had a comprehensive inspection? The Storage Tank Rule (Regulation 11.28) requires Comprehensive Inspections of each finished water storage tank at least every five calendar years or on an department acceptable alternative schedule. A comprehensive inspection is a in-depth tank inspection that includes both an internal and external inspection that covers all aspects of the condition of the storage tank including but not limited to sanitary, structural, and coating systems conditions, as well as security and safety concerns. Periodic tank inspections are mainly a visual external storage tank inspection that is typically performed by the supplier to identify evident sanitary defects (e.g., lack of screens on vents). Most water suppliers hire contractors to perform comprehensive tank inspections.

Policy DW-012 - Storage Tank Rule Alternate Inspection Schedule Justification, Section 4.6 specifies that with the Storage Tank Rule becoming effective April 1, 2016, suppliers of water are required to perform a comprehensive inspection of their finished water tanks within five years of this date and subsequently at least every five years thereafter. Please note, the five-year interval between comprehensive inspections is calculated on the calendar year rather than a specific month or date. For example, if a comprehensive inspection was completed anytime within calendar year 2016, then the following comprehensive inspection must have been completed by the last day of 2021 in order to be in compliance with the Storage Tank Rule. For another example, if a comprehensive inspection was completed anytime within calendar year 2018, then the next comprehensive inspection must be completed by the last day of 2023.

Please note! The water supplier must have conducted a comprehensive inspection on all distribution system tanks before the end of 2021 and every five years thereafter (Policy DW-012). Effective 2022, unless your distribution system tank was built after 2016 or was on a department acceptable alternate inspection schedule, a comprehensive inspection must have been completed. If a comprehensive inspection was not completed, then it is a treatment technique violation that requires Tier 2 public notice. The Field Services Section will be evaluating your documentation of your comprehensive tank inspections during your next Sanitary Survey. Please be prepared with the following information:

• When the tank(s) in the distribution system went into service
• Were comprehensive inspections completed every 5 years or are they on a department acceptable alternate schedule
• Copy of the comprehensive inspection report(s)
• Water supplier review of the comprehensive inspection report and any sanitary defects (Policy DW-010) identified (e.g., sediment exceeding 1-inch, holes, vent screens missing, etc.).
• Documentation demonstrating that any sanitary defects were corrected or are on a corrective action schedule to resolve.

Additional resources for comprehensive tank inspections, include the following: Comprehensive inspection checklist, Comprehensive inspection checklist instructions and Storage tank guidance handbook. The division’s intranet also has more information at https://cdphe.colorado.gov/dwtank.

Comprehensive inspections are important to protect storage tanks from sanitary defects and provide safe drinking water to customers. If you have any questions or concerns, please reach out to the Field Services Section at CDPHE_WQCD_FSS_Questions@state.co.us and thank you for all your efforts!

➽ Heather Young, PE, CWP