Abstract

For the first time since 2004, less newly build collective tap water installations show shortcomings. This is true for both the first inspection and the follow-up inspections preformed by the water companies. This seems to indicate a break in the trend of previous years where less newly build installations pass inspection without shortcomings. Still, one-third of the inspected installations do not comply with legionella regulations when first inspected. These non-compliances can be the cause of high to very high risk of contamination of the installation or the public mains system.
These conclusions are drawn from the inspections preformed in 2009 by the drinking water companies in newly build and existing installations. By order of the Dutch Ministry of Infrastructure and the Environment and the VROMInspectorate, the Institute for Public Health and the Environment of the Netherlands (RIVM) compile a yearly report since 2004 on the inspection of tap water installations. In 2009 more than 47.000 newly build and existing installations were inspected. The inspections have found and resolved more than 8000 situations of high to very high risk for public health.
In existing installations, the number of non-compliance found at first inspections has decreased over the years. At the second inspection of installations that do not comply, the number of non-complying installations increases. The cause of this trend is unknown, and should be investigated.
Only a quarter of the installations that must comply with special regulations for the prevention of Legionella (high-priority installations like hospitals, swimming pools, etc.) comply at first inspection. Starting from 2009, these installations are inspected according to a special intervention strategy. It is still too early to see results from this strategy.