Who should approve a dechlorination plan before work begins?
The site’s designated responsible person or dutyholder should approve the dechlorination plan before work begins, because they retain accountability for water safety, site controls and compliance. A competent water hygiene adviser and the contractor carrying out the work should review the plan for technical accuracy and safe execution, but their review does not replace the dutyholder’s approval.
Approval should be given by the organisation that controls the site’s water systems and can authorise the associated operational, health and environmental controls. In practice, this is usually the appointed responsible person, dutyholder or another formally delegated site authority. The approval should be recorded, dated and linked to the version of the dechlorination plan that will be used.
Approval is different from technical review. A competent water hygiene adviser should check that the proposed method is technically suitable, including the treatment approach, sampling arrangements, discharge route, control measures and acceptance criteria. The contractor should confirm that the plan can be carried out safely with the equipment, chemicals and personnel available. These reviews provide professional assurance, but neither reviewer should approve the plan on behalf of the person who retains site accountability unless that authority has been formally delegated.
Where several organisations share control of a site, the approval route should be agreed before planning is completed. The organisation controlling the water system may approve the technical aspects, while a principal contractor, facilities manager, environmental representative or asset owner may need to authorise related work. Each party should understand which risks it is accepting and which controls it is responsible for providing. One person should be identified as the final approving authority so that responsibility is not divided ambiguously.
The approving person should confirm that the plan addresses the actual site conditions rather than relying on a generic method statement. Their review should consider:
- the system or section to be dechlorinated and the reason for the work;
- the chemical residual, volume, flow path and likely discharge point;
- the proposed neutralisation method and how its effectiveness will be verified;
- isolation, access, drainage and containment arrangements;
- risks to people, the water system, receiving drainage infrastructure and the environment;
- sampling, monitoring and hold points before discharge or recommissioning;
- communication with affected building users, operators and other contractors; and
- the actions to take if results are outside the agreed limits or site conditions change.
Environmental or drainage approval may also be needed where treated water is being discharged to a drain, sewer, surface water or another controlled route. The site authority should establish whether the receiving network owner, environmental adviser, regulator or other competent body has requirements that affect the method. External confirmation does not remove the need for internal site approval; it forms part of the evidence that the proposed discharge is acceptable.
The person approving the plan does not need to carry out every technical calculation personally, but they should have sufficient authority and understanding to challenge unclear assumptions and reject an incomplete plan. If they lack the competence to assess the technical content, they should obtain advice from a suitably competent water hygiene professional before signing. A signature without a meaningful review does not demonstrate effective control.
Approval should be repeated if the work changes materially. Examples include a different discharge route, altered chemical dosing, an unexpected system volume, changed access arrangements, additional contractors or a change to the planned isolation. The revised document should identify what has changed, who reviewed it and whether further permissions or risk assessments are required.
Keep the approved plan with the relevant risk assessment, method statement, permits, technical review, monitoring results, discharge records and completion information. This creates a clear audit trail showing who authorised the work, what controls were agreed and whether the work was completed as planned. It also helps the water management team assess any effect on subsequent sampling, disinfection, recommissioning or routine monitoring.
Approval should be treated as a formal control decision, not merely a signature on a contractor’s method statement. The approver should confirm that the required permits, isolations, access arrangements and discharge permissions are either in place or assigned to named people before work is authorised to start.
A useful test is whether the proposed approver can stop the work if a control is missing, require the plan to be amended and ensure that the necessary site resources are available. If they cannot exercise that authority, they are better placed as a reviewer or contributor rather than the final approving authority. This distinction helps prevent a technically reviewed plan being treated as authorised when the organisation with operational control has not accepted it.
Get expert guidance on approving your dechlorination plan
Contact Blue Fish Water Management to discuss an independent review of your dechlorination plan and the evidence needed to support its approval. Our water hygiene specialists can help identify gaps before the proposed work is authorised.