Disinfection CT Calculation and Compliance Log

Inspection template for recording disinfectant residual, contact time, and CT calculations to verify daily disinfection performance and required log inactivation of Giardia and viruses.

Inspection Details

• Inspection date and time recorded
• Facility, plant, or system identifier recorded
• Inspector name and role recorded
• Applicable disinfection SOP or operating target referenced

Disinfectant Residual and Water Quality Inputs

• Disinfectant type selected
• Measured disinfectant residual
• Residual measurement point identified
  Record where the residual was measured, such as clearwell effluent, contact basin outlet, or distribution sample point.
• Water temperature recorded
• pH recorded

Contact Time and CT Calculation

• Effective contact time recorded
  Record the effective contact time used for CT determination, not just total detention time.
• Baffling or detention factor applied
  Enter the factor used to convert theoretical detention time to effective contact time.
• CT value calculated
  CT = disinfectant residual × effective contact time.
• Required CT target met
  Confirm the calculated CT meets the applicable daily target for the treatment objective.
• Required log inactivation confirmed
  Select the log inactivation target(s) verified by the CT result.

Operational Conditions and Verification

• Flow rate recorded
• Clearwell or contact basin level recorded
• Sampling and test instruments verified within calibration date
• Any process upset or abnormal condition observed
  Examples include low residual, short-circuiting, pump failure, alarm condition, or bypass event.

Corrective Actions and Sign-Off

• Corrective action documented for any CT deficiency
  Document the action taken or planned if the CT target was not met or if a process deviation occurred.
• Supervisor or operator review completed
• Inspector signature