Processing at Ranger Uranium mine in the Northern Territory will remain suspended for a further three months.

Plant processing operations were initially ceased in January for 12 weeks due to the risk of a tailings dam overflowing into Kakadu National Park after excessive Wet Season rain.

In an ASX announcement the company today said the suspension would be extended to avoid the risk of environmental damage.

It said owner of the mine, Energy Resources of Australia, had already experienced a 42 percent drop in production in the first quarter of 2011 in comparison to the first three months of last year as a result of the processing shut down.

ERA chief executive Rob Atkinson says this Wet Season has been exceptional.

"It's been a very, very wet Wet Season, we've had 2.4 metres of rain and we've been managing water very carefully and doing everything we can to stay below operating limits.

"It's a huge concern for the business, but we have not exceeded our regulatory levels but we are coming very close to that."

Northern Territory Environment Centre nuclear free campaigner Cat Beaton says it's the responsibility of both the company and the Government to protect the environment.

"We all live here, Kakadu is our backyard and ERA and the Government have the responsibility of keeping in check the practices in place and I think it's the responsibility of the Environment Centre to look into these issues.

"There's been a history of lots of leaks and spills out at ranger, it's not a flawless record."