environmental assessment survey for a controversial $65 million housing development which sits over a unique cave system.

And Save Open Spaces spokesman Ian McDonald-Smith stressed no-one could absolutely guarantee that the delicate cave system would not eventually be destroyed by chlorine from pools or pesticides.

He was speaking after a second report on the Ship's Hill site in Hamilton Parish commissioned by would-be developers Bermuda Properties Ltd. was given an A by the Environmental Assessment Institute.

Mr. McDonald-Smith said: "Chlorine is a huge issue -- it's highly toxic and even diluted by a factor of 100 it would be expected to kill 50 percent of the cave animals which came into contact with it.

"There are going to be accidental spillage around pools in the natural course of things -- it's inevitable.'' He said a new sewage treatment plant would be likely to rely on microorganisms to break down waste -- but chlorine pumped into any such system would kill of those microorganisms too, reducing the efficiency of the entire system.

A top scientist retained by SOS and other heritage groups on the Island has already made a preliminary study of the Bermuda Properties Ltd (BPL) report, which dismissed fears for the future of the area and the caves, home to 11 endangered species of tiny shrimp-like creatures.

SOS consultant Dr. Phil Smith of Aquatic Environment Consultants said his preliminary rebuttal concentrated on four main issues: planning restrictions in force; alternative locations; impact on woodland; and the effect on the caves.

Dr. Smith quoted seven separate planning rules mitigating against the development, including one insisting on "the protection of caves'' taking "precedence over all other planning considerations'' and rules to protect woodlands.

"As an outsider, I cannot understand how the development on Ship's Hill can be seen as acceptable due to the significant impacts on woodland and cave habitats,'' he said.

Alternative sites could have been given more consideration and he said BPL had not shown "the only sensible location for the development is on Ship's Hill''.

Dr. Smith said the estimated loss of woodland (31 percent) meant the effect on the remaining woodland would be greater.

Bird life would be hit by the increase in cats from a residential development.

And he insisted, despite claims to the contrary, that pesticides from the new gardens, chlorine from pools, oil leaks from cars caused by the prestige 26-home, 14-swimming pool proposals could get through the soil and small natural fissures and kill off life in the caves.