Cooling Tower Water Treatment and Legionella Inspection Log

This template covers the core checks used to manage cooling tower water quality and Legionella risk: inspection details, water chemistry, biocide dosing, biological testing, and equipment condition. It is designed for routine field use, so the log captures both measured values and visible deficiencies such as scale, slime, leaks, or unsafe access. The output is a defensible record of what was checked, what was found, and what action is needed.

Use it on the cadence required by your site water management plan, vendor program, or local policy. Many facilities run it during routine service visits, after chemical adjustments, after startup or seasonal recommissioning, and after any abnormal water quality event. If your program is risk-based, increase frequency when operating conditions change or when prior findings show recurring non-conformance.

It should be completed by a trained technician, water treatment vendor, facilities engineer, or other assigned person who understands the site’s cooling tower water management plan. The inspector should be able to recognize unsafe access conditions, chemical handling issues, and visible signs of biological growth or corrosion. If your site requires a competent person or contractor sign-off, this log can capture that role clearly.

Yes, it supports the documentation expected by Legionella risk management programs and water management plans. It is useful for tracking control measures such as biocide dosing, sample collection, chain of custody, and review of the current control plan. It does not replace a formal risk assessment, but it helps prove routine verification and corrective action.

The biggest mistake is recording only 'OK' instead of the actual measurement, target range, or observed condition. Another common issue is missing sample chain-of-custody details, which makes laboratory results harder to defend. Teams also forget to document abnormal operating conditions, such as low flow, bypassing, or recent shutdowns, even though those conditions affect interpretation.

Yes, it should be customized to your tower count, chemical program, acceptable ranges, and sampling procedure. You can add site-specific targets for pH, conductivity, and oxidizing residual, plus fields for vendor name, tower basin cleaning status, or corrective action owner. If your program uses alternate biocides or different lab methods, those can be added without changing the inspection flow.

An ad-hoc checklist often misses the link between chemistry, dosing, biological testing, and equipment condition, which makes trend review difficult. This template keeps the inspection in a consistent order and prompts the inspector to capture the evidence needed for follow-up. That makes it easier to spot repeat deficiencies, compare towers, and show that the control plan is being followed.

Useful attachments include lab reports, chain-of-custody forms, chemical SDS sheets, vendor service reports, and photos of scale, slime, or leaks. If your workflow supports it, integrate this log with corrective action tracking so out-of-range chemistry or positive biological findings automatically create follow-up tasks. Linking the log to asset records also helps separate tower-specific issues from sitewide program issues.