Application of QMRA for drinking water safety planning of treatment and distribution

This two-day, thematic course provides an advanced approach to Water Safety Planning (WSP) related to treatment and distribution of drinking water. The approach is based on Quantitative Microbial Risk Assessment (QMRA). A microbial barrier is a treatment process or a physical barrier. The treatment barriers are assessed by combining information on raw water quality, efficiency of the treatment process and the acceptable risk of the consumer. The distribution system is analysed for risk of ingression of pathogens.

Today governments and health authorities worldwide demand that water supply companies implement quality assurance schemes. As a result, most water supplies have established water safety plans. Water safety plans shall be reviewed and improved on a regular basis.

In this course you obtain a theoretical basis for analysing the microbial barriers and controlling health hazards. The course takes WSP a step further and provide a tool for quantitative risk assessment, and provision of the documentation for a safe water supply.


  • Historical background and general principles for WSP
  • Hazards and hazardous events
  • Quantitative microbial risk assessment
  • Characterization of raw water quality
  • Determining the efficiency of existing microbial barriers
  • Evaluating the health risk
  • Determining treatment strategy
  • Risk assessment of incidents in the distribution network
  • Group work based on participants’ cases


Drinking water utility managers, water safety team managers and members, and
operating staff, as well as consultants.

It is a prerequisite that the participating water suppliers have implemented water
safety plans and that consultants have a prior knowledge of WSP.

The participating utilities will be asked to provide information from their own
utilities to be used as a basis for the group work.