BUDDHIST monks at Lantau Island's Po Lin Monastery have threatened to close it to tourists to protest against a government warning that they would be prosecuted for discharging waste into nearby streams. They say they should not be held responsible and claim that most of the pollution is caused by the food stalls and hawkers who operate outside the monastery. The Environmental Protection Department (EDP) issued an ultimatum yesterday, ordering the monks to upgrade facilities to stop unauthorised kitchen waste and sewage discharge or face court action next month. The monastery supervisor Reverend Sik Chi Wai said yesterday: 'Only a third of the tourists visiting the monastery have meals here. So we should be held responsible for only 30 per cent of the pollution.' The Government made the area a water control zone two years ago and has been discussing with the monks measures to reduce untreated waste discharge into nearby streams which flow into the island's Shek Pik Reservoir. Septic tanks and waste-filtering facilities have been built, but those fail to comply with requirements. Reverend Chi Wai said the stream water was as clear as drinking water. But latest water tests by the Government found water quality unacceptable. The authorities said the problem had been worsening since the opening of the Tian Tan Buddha last December. Up to 18,000 tourists visit the monastery a day. But Reverend Chi Wai said: 'We are spending $40,000 of our own money a month on renting 80 portable chemical toilets and hiring a cleansing company to dispose of the sewage. There are only two public lavatories here. We have been forced to spend the extra money because of the Government's poor planning. 'And now it wants to lay another blame on us. In the worst case scenario, we will close our doors to tourists. Then there will be no pollution if no people come here.' He said the consultant hired by the monastery estimated it could cost $5 million to build a treatment system big enough to cope with the crowd. Tai O Rural Committee vice-chairman Lou Cheuk-wing said: 'It is not fair to ask a non-profit-making institute to spend so much on what is supposed to be a public work. The Government is going too far.' The EPD warned yesterday it was planning to take legal action next month. Senior environmental protection officer Mabel Mak Lok-sheung said it had issued several warnings to the monastery this year but there had been no improvement.