By Carolyn Dempster BBC, Johannesburg

Several South African families have taken giant steel corporation, Iscor, to court for polluting their water.

The case is being seen as one of the most important environmental legal battles in the country's history.

My whole life has been destroyed by Iscor. My childrens' lives, my wife's life.

Johann Dewing

The 16 black and white families live in Steel Valley in south-west Johannesburg, in the shadow of Iscor's massive steel manufacturing plant at Vanderbijlpark.

They claim the industrial giant has polluted their water, degraded their environment and brought sickness and suffering to their families.

The Steel Valley residents want the court to force Iscor to stop polluting their water.

Four of them are also asking for compensation because they claim that drinking the polluted water has damaged their health.

'Lakes of poison'

Johann Dewing, one of the 16 applicants demanding compensation from the steel giant, says his life and those of his wife and children have been destroyed by Iscor.

Residents have complained of kidney and bladder problems

"Even people visiting us who have been drinking the water have been affected. We've all been really badly affected."

Resident also say their properties are now worthless because the soil is polluted, their crops have failed, their animals have died, and nobody wants to buy their farms.

In affidavits presented to court, the residents and independent scientists claim that industrial waste pumped by Iscor into its waste water reservoirs has seeped underground and contaminated the water which residents pump up from the boreholes on their smallholdings.

Today the lawyer for the residents, David Soggott, described the waste dams as "lakes of poison".

He told the court that Iscor has known about the pollution problem for the past 40 years, but in spite of numerous promises to remedy the situation, has "done nothing".

Denials

Iscor denies that it is polluting the water which the applicants use, and says sewage systems and farming practices are to blame for any contaminated water.

The company also denies that it has done nothing to improve its waste disposal practises and says it has spent half a million rand upgrading its processes since 1997.

Two years ago Iscor settled out of court in a similar case, and bought the properties of hundreds of residents in the surrounding area.

They claim that there is no evidence the pollution has spread beyond these properties. The Department of Water Affairs, which regulates water use has said it will close the plant down if Iscor does not comply with the law.

The case is set to continue for the next two weeks