The water quality of 22 beaches have been rated 'good' and 11 'fair' for this weekend, according to the Environmental Protection Department's latest grading.

Compared with the grading released last week, Big Wave Bay, Clear Water Bay First, Middle Bay and Shek O Beaches have been upgraded from 'fair' to 'good'.

Butterfly Beach, Cafeteria New, Cheung Chau Tung Wan and Golden Beaches have been changed from 'good' to 'fair'. The changes are generally within the normal range of fluctuation of the bacteriological water quality of the beaches.

Seven gazetted beaches - Anglers', Approach, Ting Kau, Casam, Gemini, Hoi Mei Wan and Lido Beaches - are closed to swimmers year round because of poor water quality. People should not to swim at the closed beaches.

Many beaches are likely to be more polluted than their grades suggested during and after periods of heavy rain. Bathers should avoid swimming at beaches for up to three days after a storm or heavy rainfall.