The chairman of the Roundswell Residents Association is urging locals to find out if they are owed hundreds-of-pounds by South West Water.Graham Turner, 70, says that thousands of households are likely to be on the wrong sewerage tariff including all 1,300 houses in Roundswell. By default, all houses in the area were placed onto South West Waters Sewerage one tariff, which includes charges for surface water drainage. Mr Turner claims this is an unnecessary charge. Some people could get £400 back, he said. We want people to claim whats theirs. If someone phones South West Water, the company will check to see if anyone in your road has been switched to Sewerage two, a cheaper tariff. If they have, SWW will repay the difference. If they havent, SWW should send a surveyor to check your claim. Mr Turner said: They must be making millions just in the South West. A SWW spokesperson said: Customers can apply for the lower tariff through our website or by contacting our call centre. We try to make it as easy as possible to do, and highlight the issue on bills.To find out if you could claim any money back, call South West Water on 0844 3461010.