URGENT steps are needed to improve the water quality of Hong Kong's sea and rivers. Reports by the Environmental Protection Department (EPD) show the water is as bad as it was two years ago. The reports detail results from both marine and river water quality testing programmes conducted in 1991. The EDP's principal protection officer (water quality) Dr Malcolm Broom said the fresh water report showed that rivers in the territory's north and northwest remained heavily polluted. The marine report highlighted the serious water pollution problems affecting Victoria Harbour and other coastlines near to high population centres. Dr Broom said marine water quality was still largely poor, but the deteriorating trend was levelling off with the gradual implementation of the water control zone. He said the EDP planned to make Victoria Harbour a water control zone between 1995 and 1997. An EDP spokesman said water quality was unlikely to improve in the near future. ''It is unlikely there will be much improvement in river pollution until effective control over livestock waste disposal is possible and planned new sewerage works are completed,'' he said. ''Improvements to marine water quality will only come about with the full implementation of sewerage master plans and comprehensive enforcement of the water pollution control legislation.'' The 1991 survey covered a total of 75 river and 101 marine sampling stations.