VITAL improvement work to the overloaded Middleton One Row sewerage system will not take place until 2006.

On Monday night, Alan Tier, a works manager for Northumbrian Water, told Middleton St George Parish Council that the sewerage works had reached full capacity and could not treat another house.

He said that a sand filter had been recently installed to upgrade the works and that funding had been secured to extend the works to service residents for the next 15 years.

Mr Tier said: "The works were built in 1950 to serve a population of 1,500 people. We then completed a study in 1995 when the population was 2,500 and projected a service figure of 3,000 by 2005.

"We are now treating 3,500 and the system is overloaded.

"The good news is that we will be on site in March or April next year to dig trial holes and pits to check the sub-soil.

"But we won't start construction until 2006 because the designs have not been completed yet. It will take two years to build."

Parish council chairman and ward councillor Doris Jones welcomed the new features, but wondered if the works could accommodate the area's 5,000 residents and questioned why the start date for the improvements was so far away.

Mr Tier said that an up to date house count would be completed to establish an average number of customers.

He said: "When we design sewage treatment works we also look at the industrial use as well as the domestic population.

"At Middleton One Row we have the added complexity of Durham Tees Valley Airport which intends to expand and increase its number of passengers from 0.7m per annum to 3m in 2030.

"We are talking to the airport to get figures from them, but this is proving very difficult because they are not sure how the population is going to increase.

"Until they give us their figures, it would be unfair to prepare a final design. Therefore, there has been a delay. "

Richard Whitehouse, marketing director at the airport, confirmed that it had discussed the issue with Northumbrian Water.

He said there were would be difficulty in producing the scheme within the airport's expansion time frams. It was now looking at other alternatives.