DORSET householders will face the country’s second highest water bills from April, partly to cover rising sewage treatment costs.

According to utilities regulator Ofwat, Wessex Water will charge an average water and sewerage bill of £478 for 2013-14, topped only by neighbouring South West Water at £499.

The new rate is a 4.9 per cent rise – roughly £2 per month – on the previous year, compared with a rate of inflation of three per cent, according to the Retail Price Index.

Andy Pymer, Wessex Water’s customer services director, said the rises were necessary so the firm can meet more stringent sewage treatment regulations, and complete a £200 million pipeline project to help tackle drought.

“There are increasing quality standards we need to meet for sewage treatment to ensure beaches and rivers are kept clean, and we have more beaches in our area than anywhere but the south-west,” he said.

“We cover a very rural area, it compares to parts of Scotland, and it costs a lot more for us to transport water to remote rural places. We attempted to keep bills down with an austerity plan to put-off certain improvements until 2016, but we were told they were required by the regulator.

“We have a lot of assistance in place for customers who are struggling to pay, and I would encourage them to contact us.”