DWQR provides a second tier level of investigation of drinking water quality complaints.
When we receive details of a water quality problem from a consumer, we check that they have previously contacted Scottish Water. DWQR is only able to take on a consumer issue once Scottish Water has been given an opportunity to resolve it - this will usually mean following Scottish Water's internal complaints process: http://www.scottishwater.co.uk/contact-us/customer-service/escalating-complaints.
A similar approach is taken in the case of private water supplies where a user has raised an issue in respect of water quality with local authorities and remains dissatisfied with their response and conclusion to their formal complaints process.
Guidance on how to make a complaint about drinking water quality is available here.