STP Commissioning Checklist: 9 Essential Handover Checks

STP Commissioning Checklist: 9 Essential Checks Before Handover in KSA

An STP commissioning checklist helps a Saudi facility owner answer a practical question: what evidence should we receive before accepting a sewage treatment plant? A pump running during a site visit is useful evidence, but it does not establish treatment performance or readiness for daily operation.

For camps and residential developments opening in phases, separate completed tests from demonstrations that still depend on incoming sewage. Record those conditions before signing the handover documents.

Quick answer: what should an STP commissioning checklist cover?

Request an agreed acceptance plan, installation inspections, instrument checks, equipment and alarm tests, biological startup records, effluent results, operator training and a signed defects register. Each item needs an identifiable record, responsible person and acceptance decision. Keep contractual handover separate from permission to discharge or reuse water.

Nine checks for your STP commissioning checklist

1. Agree the acceptance basis before testing

Identify the approved design, equipment schedule, contract guarantees, test conditions and applicable authority requirements. Agree who witnesses tests and who can accept the results.

Saudi EXPRO’s testing and commissioning resource index lists separate wastewater pre-start and functional/performance checklists. This is a useful distinction, although the index does not establish a universal acceptance procedure for every private STP.

Make the STP commissioning checklist identify the required evidence at each stage, including any performance test postponed until occupancy increases.

2. Confirm installation readiness

Ask for signed inspection records covering installed equipment against approved drawings, pipe identification, access, leaks and completed electrical checks. Record equipment tags so findings can be traced to individual assets.

Confirm that the responsible specialists have cleared outstanding items that prevent safe testing. A missing guard, inaccessible isolation point or unresolved electrical defect should have a documented disposition before the affected test proceeds.

3. Check instruments and recorded measurements

Request an instrument register showing each relevant meter or sensor, its range, verification or calibration record, and the value displayed in the control system. Check that units match between local instruments, screens and exported reports.

Include this evidence in the STP commissioning checklist: a performance report becomes difficult to assess if its flow readings cannot be traced to a checked instrument.

4. Witness normal and standby operation

Use an approved test sequence for manual and automatic operation. Record equipment starts, stops, duty changes and standby responses wherever these functions form part of the supplied design.

For example, the witness sheet for a paired pump arrangement could identify the selected duty pump, simulated changeover condition, expected response and observed result. This is an illustrative record format, not a requirement that every plant has identical redundancy.

5. Prove alarms and fault recovery

Request a witnessed alarm and interlock schedule. For each relevant event, capture the trigger, indication, equipment response, acknowledgement and recovery behaviour. Include remote notifications only where they are within the agreed supply.

Have competent commissioning personnel use an approved simulation method. Your STP commissioning checklist should record the outcome, rather than encourage operators to create an uncontrolled overflow or electrical fault to demonstrate an alarm.

6. Separate hydraulic testing from biological startup

Moving clean water through tanks can demonstrate hydraulic functions; it cannot demonstrate sewage treatment under the intended organic load. Biological startup involves establishing the treatment population, a distinction explained in the US EPA’s historical startup guidance. That document is technical background, not Saudi regulation or a source of current equipment settings.

Request dated startup logs, actual incoming flow and load information, process observations and the supplier’s operating instructions. If sewage availability is limited, state what remains unproven and agree how later verification will be completed.

7. Review effluent evidence against the correct conditions

Attach laboratory reports to the STP commissioning checklist with sampling locations, dates, operating conditions and the acceptance criteria used. Agree the sampling programme and laboratory requirements with the responsible project specialist and relevant authority.

NCEC provides a water discharge permit service. Check the actual conditions applicable to your outlet; a supplier’s handover certificate does not itself establish discharge permission. Do not substitute a generic irrigation limit for the requirements of the intended reuse route.

A single compliant sample should not be presented as proof of sustained performance outside the conditions tested.

8. Receive usable documents and operator training

Ask operators to demonstrate routine control tasks and explain their response to the tested alarms. The EPA startup manual distinguishes dry-run familiarisation from training under hydraulic load; use training records to show what staff actually practised.

Organise the handover pack so the operating team can find information without calling the installation crew:

9. Close defects and record remaining responsibilities

Finish the STP commissioning checklist with an agreed defects register. Give each open item an owner, deadline, acceptance impact and closure evidence. Clearly distinguish completed tests, accepted exceptions and deferred demonstrations.

The handover record should identify who operates the plant, pays for remaining tests and responds to startup problems. Record the contract’s warranty arrangements without assuming that every obligation begins on the same date.