02 March 2010
A maze of underground water mains running east to west across Lancashire is about to undergo a multi-million pound deep clean water bosses confirmed today.
The zigzagging pipework underneath Longridge, Preston, Kirkham and Blackpool, fed from the huge 27" Hodder Aqueduct, which underwent its own £70 million refurbishment last year. Between them, the jungle of pipes, supply drinking water to more than 30,000 household taps daily.
Warrington based United Utilities, which serves 7 million customers with clean water daily across the North West; said specialist cleaning teams would work at night starting in Longridge in March, moving through Preston's Fullwood district, into Kirkham finishing seven months later in Blackpool by September 2010.
Work will start on Dilworth Lane, Longridge Monday 15th March, on a single length of water main, which will used to rezone supplies to enable the rest of the cleaning in Longridge proceed.
Ray Melia, Project Engineer for the mammoth cleaning job said: "Last year we spent around £70 million cleaning the large 27" Hodder Aqueduct, which is over 90-years old itself, and whilst the Hodder and the feeder pipes have been cleaned before, we need to carryout ongoing maintenance to remove deposits that naturally build-up inside them.
"We use a technique called Robust Flushing. At various controlled opening points on the water network, we systematically flush short lengths of water main, and with the aid of pressure already inside the water main, we can remove all the deposits.
Mr Melia added: "This cleaning programme will help us fight against discolouration in the local water supply, so our customers will always have clean, fresh drinking water when they turn on their taps."
The full hydrant flush across Longridge will happen week commencing 5th April.
The utility firm said that harmless sediment had settled at the bottom of the pipework over the years, and flushing would remove sediment at various flushing points that have been identified in parts of Longridge, Preston, Kirkham and Blackpool.
"By working throughout the night we avoid road closures during the day." said Mr Melia, but he urged for residents cooperation and not to park over or near water hydrants and valves, so engineers can easily gain access to operate them."
Adding: "We will be writing to all those residents, street-by-street in early March starting in Longridge to let them know more about the work and asking them not to park on or near the local hydrant s. With their help, we can arrive on streets in the middle of the night and get back off them before they need to use water, and the rush-hour starts on the roads."
The Hodder has two gigantic diameter trunk mains running side-by-side a 27" and a 36" water pipe from the Forest of Bowland in the East of the county to the Fylde Coast in the West. Between them, these huge underground water motorways supply up to 219 million litres of water a day to 850,000 people in Lancashire.
Since the pipes were first put in place up to 90 years ago, deposits of iron and manganese which occur naturally in raw water from our upland reservoirs have built up on the inside of the pipes. Although not harmful to health, these deposits can result in discolouration of our drinking water.
The water firm added, none of their engineers would need to gain entry to customers' homes, and people should always be aware of bogus callers.
KEY FACTS:
The Hodder
Large diameter trunk main is the term we give to the giant water pipes that feed the vast majority of our customers in the main conurbations of the North West. Some sections of these pipes are big enough for an adult to stand up in. The Hodder large diameter trunk mains system consists of two cast iron pipes, which run from Hodder water treatment works and Stocks reservoir near the Forest of Bowland to the Fylde coast.
The first pipe is 27" in diameter and was laid in the 1920's.
The second pipe is 36" in diameter and was laid in the 1950's.
The Hodder pipeline is 84km long and supplies water to customers in the Ribble Valley, Blackburn, Preston, Blackpool and the Fylde coast.
Between them both these pipelines supply up to 219 million litres of water a day to 850,000 people in Lancashire.
Longridge - facts
Work is due to commence early March 2010. The full flush will happen 5th April and is estimated to take two weeks to complete
13km of pipe will be cleaned in Longridge over a two-week period
The Hodder provides 3,000 people in Longridge with safe clean drinking water daily
Notes to editor
After flushing some customers may experience a small amount of discolored water, this is normal. If this does happen, you should not run your hot water or do any laundry. Turn on and run your cold water until the water clears out of your pipes. We recommend that you do not do your laundry on the night we are flushing the water main on your street.
For further media information, contact:
Shaun Robinson, at United Utilities press office on (01925) 237088
(please note our new 24-hr number) *All calls are recorded and may be monitored