THE Habitat ii conference held in Istanbul, in June this year, had one message broadcast loud and clear: cities could be cleaned up and managed sustainably if only communities chose to do so. Twelve communities who have already demonstrated this were given the Best Practices Award by the UN. One of these was the city of Chattanooga in Tennessee, US, where the combined efforts of thousands have resulted in the purification of the air and water of the nation's most polluted city. In the process, the local economy has also diversified.

Located in south-eastern Tennessee, Chattanooga has come a long way since the early 60s when foundries, food processing industries and manufacturers of anything from carpets and soaps to boilers for nuclear plants set up base here. The availability of cheap land, labour and power attracted them to the area. The small nondescript town soon metamorphosed into an industrial city that produced hundreds of jobs and goods. It also produced a crisis.

The city's air was so full of pollutants that residents had to drive with their headlights on even during the day. Morning walks often left traces of soot on clothing and around the nose. The incidence of tuberculosis was three times higher than the national average. In the meantime, as labour-intensive jobs gave way to capital-intensive ones, Chattanooga no longer remained attractive for industrial investment. By the mid '70s, many of the city's older industries relocated to other states in the us or overseas. The industrial boom had gone bust. Abandoned factories began rusting along the Tennessee river. Unemployment and crime rose. Urban decay seemed there to stay.

However, the people realised that change was essential. Says David Crockett, a Chattanooga city councilperson, "We were like a drug addict who hits rockbottom and needs rehabilitation." In 1983, a 'visioning process' was initiated to get the city out of the mire it had sunk into. Chattanoogans expressed their 'vision' of what the change was to result in, through the process, A non-profit organisation, the Chattanooga Venture, was set up for the purpose. Rather than have a small coterie of people deciding the city's future, the Venture invited all residents to come forward with their notions on what their city should took like. The result was 1,700 people sitting through a series of brainstorming sessions that lasted 20 weeks. The ideas borne from the exercise were concretised in the form of 34 goals for 'Chattanooga: Vision 2000'.

Even though Vision 2000 included 223 projects, the city is most proud of the Chattanooga Neighbourhood Enterprise: an organisation involving both public and private participation, set up to make housing more affordable for residents belonging to the lower income group. The conversion of the riverfront - with its series of abandoned factories - into a park, was on the agenda too. Running eight km along the river, the park shall extend another 35 km on both banks of the river . Residents have also tried to reduce the damage done by downtown development. Sidewalks in the city have been remodelled using bevelled bricks to allow water to flow into the spaces between them, thus reducing the load on the storm-water drains. Trees were planted along the streets and in parking lots. Two thousand oil-skimming devices were installed in parking lots to prevent oil from getting into the water- ways. The old buses in town were replaced by what is now the US's second largest fleet of electric buses.

A conscious effort was made to avoid turning the city into a concrete jungle. Instead of replacing the city's century-old Walnut Street bridge with a modern highway, the old structure was preserved and converted into a pedestrian walkway. Historic buildings of the city like the famous Tivoli theatre were restored. Five-star hotel chains were discouraged from coming to the city. Instead, city planners encouraged the renovation of small hotels, inns and bed-and-breakfast establishments. Street vendors and musicians were encouraged, the aim being to put forth a friendly image of the city centre. Another successful initiative has been the Tennessee Aquarium, the US's largest exhibit of freshwater fish, which attracted 1.5 million visitors in its first year and has pumped an estimated US $133 million into the local economy. "Five years ago, you would have driven through this area with your windows rolled up," smiles Crockett.

However, the most challenging task was the revitalisation of the abandoned and derelict industrial area of the city into an environmentally-advanced commercial-zone. Chattanooga hopes to be home to the world's first zero-emissions industrial park. The city planners want industries to recycle more resources, use raw materials to the full and create as few unwanted by-products as possible. And if by-products are unavoidable, they could be used as raw materials for other industries. This means that a whole network of industries efficiently feed off the by-products generated by another. By doing so, emissions will not only be curbed but will be entirely eliminated.

"Zero emissions is both an environmental and a terrifically powerful business concept," says Paul Tebo, vice president of DuPont's safety, health and environment division. In 1995, the company opened a carpet reclamation plant in Chattanooga to process 450,000 kg of used carpets every month. The recovered nylon is sold and eventually used to make car parts. The fibres are used to strengthen soil embankments.

By 1992,85 per cent of Vision 2000's goals had been met. The whole exercise was so popular that in 1993 it resulted in another visioning exercise called Revision 2000. The number of grassroots groups that have worked towards cleaning up the city's image and sought "to give something back to the community", has mushroomed.

Meanwhile, there have been murmurs of discontent alleging a form of environmental racism. Says Peter Montague, director of the Environmental Research Foundation, "It may be true that they are depolluting the air where white people live, but I find no evidence of it being true for the African-American population of chattanooga." In fact, the Chattanooga creek, with its heavy load of sediments contaminated with coal tar and other toxic substances -piled two m high in some places - runs through predominantly African- American localities. Though a few clean-up sessions have been held, the creek has received little attention.

But, there is no denying that Chattanooga has taken not a step but a leap in the right direction. US vice president Al Gore commented, "It (Chattanooga) has undergone the kind of transformation that needs to happen in our country as a whole." It may already be happening as Chattanooga has inspired a number of cities not just in the us but even in far-off Namibia, Fiji and the Netherlands, to plan industrial ecosystems based on the Chattanooga approach.