Application of occupational health and safety management system at sewage treatment plants

Sewage treatment plant (STP) operators are exposed to variety of hazard during wastewater processing. The aim of this study is to identify and manage these hazards, particularly in a local STP in Malaysia, through Occupational Health and Safety Management System (OSHMS). Initially, reported hazards data were collected via review of literatures, questionnaire distribution and interview with experts. Then, the most risky hazards based on conditions of selected STP were identified. Subsequently, the hazards were ranked based on severity and likelihood. Results show exposure to excessive noise, skin irritation and slip and fall are the main concerns of workers in the site. Therefore, noise mitigation was done using sound absorbers. It was indicated that the level of existing noise (94.2 dB) was reduced to 92.1 dB and 90.6 dB by application of carpet and cardboard, respectively. Skin irritation risk is suggested to be mitigated by installation of auto-cleaner, self-cleaning bar screen and scraper blades at the site. In addition, cordoning off areas while cleaning is in progress and provision of ramps at cleaning area around the clarifier are found to be the appropriate solutions for slip and fall risk at the site.