New Storage Tank? Prior Approval Required

Prior to 2010, the Department did not consistently inspect, review, or approve storage tanks within distribution systems. The Department did however approve storage tanks located at drinking water treatment plants for the purpose of achieving necessary disinfection for treatment. The Department would like to use this opportunity to remind systems that all new storage tanks and major modifications to storage tanks must obtain prior approval from the Department’s Engineering Section. Obtaining prior approval will help ensure public health is adequately protected and help make sure that hatches, vents, and overflows will be acceptable to Department inspectors on future sanitary surveys. This can save your system the time and money associated with having to repair or replace these items in the future.

The two articles below were published in 2009 and 2019 respectively. In the 2009 article, the Department introduced the concept of requiring storage tanks to receive prior approval from the Department before being constructed. A decade later in 2019, the Department realized that some pump station wet wells (which are considered storage tanks) were being installed without approval and reminded the regulated community that those structures are considered storage tanks as well.

As with all design-related questions, should you have a concern or question about which types of projects should be submitted to the Department, please visit our design approval website or feel free to contact us CDPHE.WQEngReview@state.co.us.

➽ Tyson Ingels, Lead Drinking Water Engineer

1. 2009 Aquatalk Article: Submitting Plans for Storage Tanks (updated references in parentheses have been added):

Prior Design Review and Approval Requirement Extended to All Storage Facilities

➽ Gary Soldano

Starting in January 2010, the Safe Drinking Water Program will require prior approval of all such projects as required by Article 1.11 (current regulatory reference is Section 11.4(1)) of the Colorado Primary Drinking Water Regulations. This requirement has been in place for many years for storage vessels that are actively used to provide disinfection contact time. The requirement will be extended to all storage tanks in an effort to address issues preventatively rather than upon discovery during sanitary surveys or, worse yet, waterborne disease outbreak investigations.

The applicable design criteria for storage facilities can be found in Appendix I of "Design Criteria for Potable Water Systems ... " (current reference is Chapter 7 of the Colorado Design Criteria for Potable Water Systems, 2022 version). As many readers know, a stakeholder group process has been established to update that document and will resume work to finalize a revised document in the near future. Until that process is completed, the current criteria will continue to be used (criteria were updated in 2013, 2017, and again in 2022).

To prepare a complete submittal, water system staff and consultants should review the design criteria and obtain an "Application for Construction Approval" form from engineering section staff or the section's Web page links that can be found at https://cdphe.colorado.gov/design (hyperlink updated to be active).

Applicable design calculations should be bundled with design drawings and specifications for submittal to the engineering section unit manager whose geographic area includes the county in which the water system is located. For community water systems, a professional engineer's seal and signature is required on the documents.

If you have any questions about the process, please contact an engineering section staff member or unit manager. We look forward to working together with water systems to ensure safe drinking water throughout storage and distribution systems in this effort.

2. 2019 Aqua Talk Article: Submitting Plans for Pump Station Wet wells to be approved as Storage Tanks