Sewage Works (Hansard, 21 June 2000)

§ Mr. Gorrie
To ask the Secretary of State for the Environment, Transport and the Regions what monitoring system is in place to ensure that the precautions required by law when parties of school pupils or organised parties of adults visit water treatment or sewage works are taken. [126282]

§ Mr. Meacher
Employers in the water supply and sewage treatment industry have general duties placed upon them by the Health and Safety at Work etc Act 1974 to ensure that, so far as is reasonably practicable, visitors are not exposed to risks to their health and safety.
The Management of Health and Safety at Work Regulations require employers to carry out a suitable and sufficient assessment of the risks arising from their undertaking to the health and safety of persons not in their employment. This includes members of the public.
Risks to health, including biological risks, are also covered by the more specific requirements of the Control of Substances Hazardous to Health Regulations 1999. They require the employer to carry out a risk assessment and where necessary to implement suitable measures to reduce the risk. This duty would extend to groups visiting the site.
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The Health and Safety Executive is responsible for the inspection of water treatment works and sewage works. Inspections of water treatment companies would include an assessment of their ability to manage and control risks, including, where appropriate, risks to the public.

§ Mr. Gorrie
To ask the Secretary of State for the Environment, Transport and the Regions what assessment he has made of whether washing screens in the screen houses of sewage works with untreated effluent produces a local atmosphere containing biological agents of a hazardous nature. [126269]

§ Mr. Meacher
HSE has undertaken at least one local intervention to monitor levels of aerosols in a screen house and at visits to water treatment companies over the years has looked into the biological risks arising from the process and the way they are controlled.
There are potentially hazardous micro-organisms in all sewage and a range of reasonably practicable precautions should be taken to control the risk.
HSE made a number of recommendations including improved washing facilities, disposable overalls, respiratory protective equipment and improved ventilation. Although they had initially recommended the use of clean mains water or its equivalent for screen washing, they accepted that this was not reasonably practicable given the very large volumes used and the fact that a new secondary treatment works is being built and that biologically treated effluent will be available for screen washing from September 2000, with the plant being fully commissioned by the end of 2000.
At a national level HSE works with the water industry's national trade body, Water UK, to help identify and resolve health and safety problems in the industry. Work has been carried out at national level on the microbiological risks from sewage, including those encountered at sewage treatment works. HSE produced guidance for employers and workers in 1995.
Screens are usually washed with water which has been through the treatment process ("final effluent") which, while not of drinking-water quality, has fairly low levels of micro-organisms. However, where the treatment facilities are limited, as at Seafield, the water used will have higher levels of micro-organisms. The main risk is from ingestion/swallowing and from splashes on the skin and in the eyes. Aerosols containing micro-organisms are likely to be produced in screen houses from the general flow of sewage and also from the washing down of the screens. These aerosols can pose a risk to health from inhalation, depending on droplet size and the type and amount of micro-organisms present.