POTABLE WATER TREATMENT: Statoil extending staff awareness of potential water liabilities

Offshore drinking water specialist E.C.T. Offshore Service this year staged its first course for land-based personnel working for Statoil. E.C.T. has been educating the company’s offshore crews for some time on how to safeguard clean drinking water supplies, but Statoil now wants this knowledge also disseminated among land-based staff such as doctors and health workers, as well as the teams responsible for designing offshore installations.

According to E.C.T’s offshore manager Yvonne Putzig, Statoil is concerned particularly about its crews contracting Legionnaires’ disease, with several cases reported in Norway.

E.C.T. also has been requested by Statoil to perform studies on the vulnerability of drinking water systems on specific offshore installations. The first of these studies was applied on the Draupner platform, and others are scheduled for later in the year. Follow-up work also may be requested.

Norwegian sector operators in general are more aware of the need to ensure that offshore drinking water systems are safe. But Putzig is concerned that the Norwegian Institute for Public Health (NIPH), the regulatory body for offshore drinking water systems, is neither taking the legionella risk seriously enough, nor requiring companies to implement sufficiently stringent tests.

Legionella bacteria can propagate only in bunkered water - they never have been found in sea water, Putzig says. But every installation has to use bunkered water now and then. “We recommend that they should sample the water every three months,” she says.

The NIPH claims the presence of legionella bacteria will be indicated by a high bacterial count. Putzig disagrees, pointing out that legionella bacteria propagate in an intra-cellular fashion in other micro-organisms such as free-living amoebae, meaning that dangerous levels of legionella can be present, even with a low bacterial count. Moreover the legionella organisms prefer a temperature of around 37° C, and since water is often tested at lower temperatures, when they are inactive, it is possible to miss them.

When the water is heated up, however, they can be swiftly reactivated - in showers, for instance, when they may invade user’s lungs as they breathe in water vapor.

Knowledge of how Legionnaires’ disease arises has improved considerably, thanks to work by the Sintef research institute in Norway and by the health authorities in Sweden. A Sintef microbiology expert, Catrine Ahlén, currently is performing a survey of the safety of drinking water systems used in the diving industry. She also participates in E.C.T’s drinking water treatment training courses.

For more information contact Yvonne Putzig, E.C.T. Offshore Systems. Tel +46 3153 0040, fax +46 3153 0045,[email protected], www.ectoffshore.se