GOLD Fields said yesterday it was building two new water treatment plants at its Tarkwa mine in Ghana after the Environmental Protection Agency ordered it to suspend heap leach operations.

The agency raised concerns about the level of dissolved salts in water discharged from the heap leach operations, which generate a quarter of Tarkwa's annual production.

Tarkwa last year contributed 717000oz to Gold Fields' production of 3,49-million ounces.

The agency ordered the suspension of the heap leach operations since July 16. This has meant Gold Fields cannot stack more material onto the heaps or add more solution that percolates through the broken ore, forming a gold solution that is collected at the bottom.

However, Gold Fields has collected pregnant solution that is still filtering out of the heaps, which meant there has been "no material impact on production to date", the company said.

Gold Fields will spend $26m to build two water treatment plants by the end of the year.

The construction of the water treatment plants is something Gold Fields has been planning since last year, but the discussions with the agency have prompted the company to embark on the project.

The water treatment plants should be built by the end of the year, it said. The contract to build the plants was signed last week.

Gold Fields is in talks with the agency about reopening and resuming operations at the heap leach pads.

It is stockpiling the low-grade ore from its opencast operations, which feeds the pads.

It will be a quick process to resume stacking the pads, said company spokesman Sven Lunsche.