It follows criticism of the island's practice of discharging raw effluent into the sea.

The news comes as the campaign group Surfers against Sewage makes another visit to the island to protest against its lack of sewage treatment.

It claims water quality has worsened in the past decade and warns fewer beaches may meet EU water standards in future.

Green paper

Richard Hardy, SAS Campaigns Director says: "It is clear that fewer beaches in Guernsey are meeting the higher (guideline) EU water quality standard than they were in 1996.

"With bathing water legislation set to become tighter in the next few years the States will face some tough decisions if they hope to keep pace.

"SAS hope the forthcoming green paper will encourage reasoned public debate and lay the foundations for a sustainable, healthy and environmentally friendly solution."

The Public Services Department says its green paper will outline the implications of maintaining and upgrading its sewer system.