To be eligible for a new appointment, the qualifying site must meet at least one of the following Ofwat criteria.
1. Unserved criterion
There are no other NAV companies currently providing water or sewage services to the area in question.
2. Consent criterion
The NAV company has the consent of all NAV companies that currently provide water or sewage services to the area in question, and any existing companies agree to a site or premise transfer.
3. Large user criterion
The developer or customer(s) of the site wishes to appoint a new supplier to serve their area/premises and is a large user of water or sewage services, i.e. an annual minimum of 50 megalitres of water for areas in England, and 250 megalitres for areas in England and Wales.