The West Australian waste-disposal technologist Environmental Solutions International is continuing to win business in the eastern states. Its latest contract is to design and equip a $20 million sewage treatment plant for the Blue Mountains area, west of Sydney.

The contract is the biggest so far for ESI's innovative waste-water-treatment systems. Until now it has sold smaller installations to country towns and commercial operations such as dairies, meat-processing plants and breweries, which produce a lot of nutrient-loaded waste water.