Review your tower programme
- Scope
- Review operating records, water treatment arrangements and the agreed inspection scope.
- Before you enquire
- Existing contractor scope, operating records and test reports.
- Quotation and scheduling
- The quotation identifies agreed work, tests and records. Price and scheduling depend on the system, access and any required downtime.
- Next step
- We reply within one working day, then confirm the scope and whether a site assessment is needed.
For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.
Delegating to a contractor does not delegate the liability. The building owner and duty holder remain responsible, which creates an awkward question: how do you know the contractor is doing what the reports say? Most building owners have no independent way to check.
For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.
What the audit checks
- Water quality against the EMSD limits, including Legionella
- Records — are treatment and cleaning logs complete, dated and consistent?
- Physical condition of the tower, basin, fill and drift eliminators
- Dosing equipment — is it actually feeding, calibrated, and maintained?
- Programme design — is the chemistry right for this water and this operating pH?
- Gaps that could lead to an EMSD notice
- A written report with clear findings and prioritised actions
What happens on site
- Scope. We agree what is being audited and why — due diligence, a contractor review, or pre-sampling assurance.
- Site inspection. The plant, the equipment and the physical condition of the system.
- Sampling. Water tested independently, including Legionella where relevant.
- Records review. The logs and reports, checked for completeness and internal consistency.
- Report. Findings, evidence and prioritised actions, in plain language you can hand upward.
What the audit is measured against
An audit is not an impression. It is a line-by-line check against Part 2 of the EMSD Code of Practice for Fresh Water Cooling Towers — the part every building operating a tower has to follow. The main items we check:
| Legionella | Under 10 cfu/mL counts as not detected; 10 cfu/mL or above but under 1,000 requires investigation, programme review, immediate online disinfection and a resample within 3-7 days; 1,000 cfu/mL or above requires immediate emergency disinfection and a resample within 3 days |
| Heterotrophic colony count (HCC) | Interpret results and determine follow-up actions using Table 2.4 of the applicable EMSD Code of Practice. Actions depend on the result and follow-up history. |
| Routine monitoring | EMSD reference minimum: HCC monthly and Legionella quarterly. At medical and health care premises, both are monitored monthly; follow-up frequency depends on results. |
| Cleaning frequency | Cleaning, desludging and disinfection at least every six months |
| Standby towers | Run at least one hour a week; standby units holding water stay treated and monitored |
| Records | Operation and maintenance records kept at least two years and available on request |
Beyond the numbers we also look at whether the programme actually works. The Code's reference pH range is 7 to 10, but above pH 8 most free chlorine has converted to the weakly biocidal form — a tower can sit perfectly inside the pH range and have almost no disinfecting power. That is the most common reason for a normal chlorine reading alongside a Legionella exceedance, and the reason an audit looks at programme design and not only at the lab sheet.
The FWCT Scheme annual audit
The Code of Practice sits on top of the EMSD Fresh Water Cooling Towers (FWCT) Scheme — the scheme that lets buildings in designated areas use fresh water for evaporative cooling. Joining the scheme is what makes a tower lawful to operate; the Code is the rulebook you agree to follow.
For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.
For the full requirements of the Code, see the EMSD Code of Practice explained; for the water testing inside an audit, see laboratory testing.
Why it matters
An audit is most valuable when you suspect nothing is wrong. By the time a sample comes back high, the audit would have paid for itself several times over. It is the cheapest item on this site and the one that most often changes a decision.
What it costs to get this wrong
The cost of not auditing is that you find out from the EMSD instead. A nuisance notice arrives with a deadline, emergency decontamination costs, and a documented history that now looks thin under scrutiny. An audit converts an unknown into a managed item — and if it finds nothing, you have bought a defensible record that your programme works. See the real cost of doing nothing for how that value compounds.
Common questions
Will you audit a tower another contractor services?
We can discuss an assessment of a tower maintained by another contractor. For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.
Is an audit the same as an EMSD inspection?
No. The EMSD is the regulator and can sample your tower at random. Our audit is a private assessment for you, designed to find and fix problems before a regulator does.
What if the audit says our current contractor is doing fine?
Then that is the report you get. An audit that always finds fault is not an audit, it is a sales tool — and any competent engineer can tell the difference.
Is an annual audit required under the EMSD Fresh Water Cooling Towers (FWCT) Scheme?
For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.
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Scope and records
The agreed quotation defines the work, analysis, deliverables and schedule.
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For annual audit enquiries, the applicable scheme requirements, auditor competence and separation from the tower’s operation and maintenance activities must be confirmed before appointment.