The Field Services Section (FSS) just wrapped up the 2024 inspection year (IY24) in September 2024 and the new IY25 inspection year started in October 2024! We appreciate all the assistance from public water systems in completing 497 sanitary surveys in 2024. In this article we will discuss one of the most frequently cited significant deficiencies from IY24: T119 Proper treatment operation of surface water or groundwater under the direct influence (GWUDI) systems.
Many suppliers of surface water or groundwater under the direct influence (GWUDI) have participated in the Disinfection Outreach and Verification Effort (DOVE) led by the Engineering Section. DOVE reviews typically include a detailed assessment of the disinfection process and thorough documentation of all other unit processes at all active surface water treatment plants. The two end results of the DOVE review are 1) a facility-specific Monthly Operating Report (MOR) and 2) a Record of Approved Waterworks (RAW). The RAW is issued by the Engineering Section and it covers all the supplier’s approved treatment and storage facilities and water sources. To find you facility's RAW please visit this website and type in your PWSID or the name of your facility.
The RAW includes conditions of approval specific to the treatment plant that are evaluated during the sanitary survey. These conditions of approval are important operational requirements specific to each facility that are in place to ensure the production of safe drinking water and protection of public health. All suppliers are encouraged to be familiar with their RAW; especially the “conditions of approval” for each facility.
Frequently seen RAW conditions of approval that are evaluated during the sanitary surveys include but are not limited to:
- For suppliers reporting the log inactivation ratio achieved in their MOR:
- Clearwell levels and flow rate must be measured and recorded at least as often as each disinfectant residual monitoring event as defined in Section 11.8(3)(c) of Regulation 11. The records of clearwell volume and flow rate are subject to Division review during sanitary surveys.
- Water temperature and pH must be measured and recorded as often as necessary given source water quality conditions but at least as often as once every week. These records are subject to Division review during sanitary surveys.
- For suppliers reporting the lowest daily chlorine residual value in their MOR:
- The minimum contact time volume must be measured and recorded at least as often as each disinfectant residual monitoring event as defined in Section 11.8(3)(c) of Regulation 11. The records of contact time volume is subject to Department review during sanitary surveys.
- Tank level sensors typically are required to be verified at least annually to ensure measurements are calibrated and accurate. Records of level sensor measurement confirmation must be kept and are subject to review during sanitary surveys.
- Any contact tank bypass valves (if present) must be confirmed as being operationally closed at least once per year by appropriately actuating the valve. If the bypass is operated at any time, the supplier must notify the Division prior to use. Records of bypass valve annual actuating and maintenance must be maintained and are subject to Division review during sanitary surveys. A common method for verifying valve closure and valve actuator integrity is to count, and keep a record of the number of actuator turns from open to closed and verify that the number of turns counted is correct for the valve type and size.
- Suppliers using alternative filtration technology must continuously meet the design, performance, and operation and maintenance requirements established in Sections 4.3.9.6 – 4.3.9.8 of the Design Criteria and in the Department’s Acceptance letter for the specific filtration technology/vendor.
- For bag and cartridge filtration systems, this includes the requirements to not exceed the maximum specified pressure differential and keep a record of daily routine pressure differential readings and filter change outs and these records will be reviewed during the sanitary survey. Specific spare parts may also be required to be on hand and will be checked during the sanitary survey.
- For membrane systems, suppliers must maintain an operation and maintenance manual for the filtration system. All integrity tests and Clean In Place (CIP) procedures must follow manufacturers prescribed procedures. The supplier must also keep records of the following operational parameters and the records will be reviewed during the sanitary survey:
- Integrity test date, results (pass or fail), and initials of person performing the test
- Clean in place dates with clean water permeability and integrity test results.
- Filter maintenance and fiber repair results
- Filter replacement date and reason for replacement.
Please review your RAW and make sure you are aware of the requirements established by any conditions of approval and keeping the required records. The RAW conditions of approval and site-specific records will be reviewed during the sanitary survey and if there is an issue, a T119 Significant Deficiency may be issued. According to Regulation 11, Section 11.3(72), a significant deficiency means: any situation, practice, or condition in a public water system with respect to design, operation, maintenance, or administration, that the state determines may result in or have the potential to result in production of finished drinking water that poses an unacceptable risk to health and welfare of the public served by the water system. Significant deficiencies must be addressed in writing within 45 days after the sanitary survey letter and any significant deficiencies that remain unresolved after 120 days or past an department approved schedule will be referred to compliance for a type 45-violation that requires Tier 2 public notice (30 day public notice with health effects language).
Please check the conditions of approval in your RAW to protect public health and avoid significant deficiencies during your next sanitary survey. If you have any questions regarding your RAW, please contact the Engineering Section. If you would like additional assistance on technical issues or sanitary survey preparation, please sign up for individualized coaching here. For any questions or concerns about sanitary surveys please email our Field Services team at cdphe_wqcd_fss_questions@state.co.us.
Thank you for all your efforts to protect public health!
➽ Heather Young, PE, CWP, Field Services Section Manager
➽ Andrew Rice, PE, Engineering Section
