In taste tests, few people can tell the difference between bottled mineral water and filtered tap water, but consumers can appreciate the difference in the impact on their wallets or weekly shop.

This is the experience of managing director David Banfield and his team at Brita Water Filter Systems at their headquarters in Bicester.

"It can cost as little as 4p a litre for filtered water, whereas the cost of bottled mineral water can be anything from 35p to 40p a litre, and even more," said Mr Banfield.

And the message is coming through loud and clear that tap water filtered through a Brita product in a consumer's own home is more environmentally and carbon footprint friendly than bottled water, which has been transported from, for example, the Peak District, Scotland, France or even further afield.

There are no air miles with water being on tap, so to speak, in the kitchen.

"A filter cartridge in one of our jugs or kettles can last for 150 litres of water and the cartridge is recyclable. With us there are no plastic bottles to throw away," he added.

While filtered water is already popular, Mr Banfield believes one of the company's biggest challenges is to encourage people to drink more water.

"Our general overall consumption of water for all needs has increased, but not our level of drinking water. If anything it has gone down.

"We believe in the recommended benefits of drinking two litres of water a day. We need water for hydration and when you consider 80 per cent of our brains is water, we must drink water to feed our brains," said Mr Banfield.

Brita has strong relationships with Government sponsored health agencies and the company has been helping to improve children's health through schools. Teachers have confirmed that drinking water improves children's concentration and behaviour in classes.

"Our challenge is to get people to drink more, although I admit two litres a day seems a lot," he said.

Brita has 80 per cent of the annual £105m UK market for filtered water systems, and also 80 per cent of the market world wide. Its 64,500 sq ft plant with 150 staff in Granville Way, off Launton Road, Bicester, manufactures "millions" of filters each year, for Britain and Europe.

The Princess Royal opened Brita House in November, 2004, following the firm's £10m move to Oxfordshire from Sunbury-on-Thames, Middlesex.

"Looking back, I am convinced we made the right decision to move to Bicester in terms of the town's location and the quality of staff we were able to recruit here. Bicester is centrally located and is within striking distance of the distribution warehouses of some of our major customers, like Sainsbury, Tesco, Asda, Argos and Homebase," said Mr Banfield.

"The M40 gives easy access to London Heathrow and Birmingham airports and the Chiltern Railways service is another big asset. It is better to catch a train and be in London in an hour or less, than sitting in a traffic jam," he said.

"Another plus for Bicester was that staff were willing to re-locate from Sunbury. In addition, we were searching for somewhere to put everything under one roof - we were rattling around in three buildings in Sunbury - we had a lot of encouragement and support from Cherwell District Council. It was very keen for us to come to Bicester because of the variety of jobs we were offering - manufacturing, distribution, sales and marketing.

"We have settled in here and we have room to expand our building upwards and outwards."

Brita was founded in 1966 by two German technologists and the company is still German owned. The company is named after the daughter of one of the foundes.

Brita has two divisions, one for consumers with its range of jugs, kettles, chillers and coolers, and the other for the catering and vending industries, including the ever-expanding coffee shop trade. One of its biggest clients is Costa Coffee.

The products have been improved over the years as people become more conscious of the benefits of filtered water.

"At one time people just thought that they needed filtered water when visiting somewhere like Spain. But now they appreciate filtered water in this country, where water supplies are basically safe," said Mr Banfield.

Brita has moved into supplying filters for branded household products, like Breville kettles.

And a recent innovation is three-way kitchen taps. Two taps supply the hot and cold water, while a filter unit under the sink means filtered water is available, too.

In Bicester the company has plans to become carbon neutral, or to cut its carbon footprint by next year. This will include reducing travel by using video conferencing and encouraging staff to share car transport.

n Contact: www.brita.net/uk