Environmental officials yesterday declared open the beaches in Stanley and Tuen Mun contaminated with leaking sewage. They said tests showed bacteria levels had dropped. Overflowing sewage at Stanley forced the closure of Stanley and Hairpin beaches on Monday, the third sewage contamination incident in two weeks. The beaches were ruled out-of-bounds after Drainage Services Department officers noticed the pumping system in Stanley was failing to cope with the inflow, resulting in untreated sewage flowing into the sea water. A week earlier, St Stephen's Beach, on the other side of Stanley peninsula, was placed off-limits following a sewage leak. It later emerged that partially treated sewage had been flowing out for nine days before the beach was closed. Two weeks ago pierced sewage pipes led to five beaches at Tuen Mun being shut. Yesterday, results of tests conducted on Tuesday revealed beach water quality at all seven beaches ranked 'poor', which is still deemed safe for swimming. Also yesterday, it was revealed that tunnel work for the much-delayed Strategic Sewage Disposal Scheme is to restart. Work on six tunnels stopped last year after contractor Campenon Bernard-Maeda complained of dangerous ground water seepage in two tunnels. Director of Drainage Services John Collier signed the $357 million contract yesterday to complete the sewer tunnel system from Kwai Chung to Stonecutters Island. Skanska International Civil Engineering, a subcontractor to the original joint venture which downed tools last year, will start work this month. The project includes completing sewer tunnels from Kwai Chung to Tsing Yi, and from Tsing Yi to Stonecutters, and deep shafts and site works at Kwai Chung and Stonecutters sewage treatment plants. When complete in August 1999, the tunnels will increase capacity of Stonecutters to 50 per cent. The $2 billion plant is running at 25 per cent capacity because of the contractual dispute which is ongoing. 'We will be claiming damages and all additional costs of completing the two tunnels,' Mr Collier said. The same amendments - limiting ground water in the tunnels - offered to the original contractors are included in the new deal. Two other contracts, part of stage one of the Strategic Sewage Disposal Scheme, have yet to be awarded.