AN exhibition promoting Hongkong's planned sewage disposal strategy will be staged at the weekend and comes as the Government puts final touches on proposals to levy sewage charges. The exhibition will be held at Lam Tin's Tak Tin Shopping Centre and at the Shun Tak Centre in Western, and will depict the seriousness of the water pollution problem in Victoria Harbour and the need for a solution. The Government is expected to announce this month plans to charge householders, businesses and industry for sewage disposal, with the charges expected to come into effect from next April.