Start with a site assessment
- Are you replacing a tank, changing the discharge route or installing a new system?
- Ask the installer to explain the proposed design and why it suits the site.
- Ask which survey or ground investigations are needed and what their findings would change.
- Have the installer identify the permissions to check with your nation’s regulator.
Ask for an itemised scope
- Equipment: make, model, size, included controls and warranty.
- Site work: excavation, tank base, pipework, drainage field or outfall work where proposed.
- Electrical work and commissioning, where applicable to the chosen system.
- Removal and disposal of the old system or waste, where included.
- Permissions, testing, final documentation, access and reinstatement.
- VAT treatment, exclusions, provisional items, payment stages and the validity date. These are quote questions, not a claim that every job needs every item.
Do not compare a product price with an installed price
- No representative numerical installation range is verified here. Check with the firms for your site.
- A retail tank price cannot establish the final project cost.
- Ask each installer to quote against the same scope and identify anything it cannot price until investigation.
Before accepting
- Who is responsible for each permission and inspection?
- Who will undertake the work, and who carries any waste?
- What are the maintenance commitments after commissioning?
- Which documents will you receive, and who resolves defects or disputes?
This guide does not decide whether a particular installation meets every condition. Check unclear rules with your nation's regulator, and service, design or price questions with the firm.