Decision support tool


Whether you intend to develop a complete Water Safety Plan (WSP) or to focus primarily on the development of a strategy for the risk assessment and management of cyanotoxins, performing this within a team of experts is highly recommended. Experts should have the necessary competence and expertise to:

  • Analyse the potential hazards
  • Assess the risks and the performance of the system in controlling them
  • Define new or improve existing control measures
  • Assess the efficiency of the management and surveillance

The team should be multi-disciplinary. It should have knowledge of the specific supply system from catchment to consumer in order to ascertain that hazards and potentially occurring hazardous events can be comprehensively identified and evaluated. All company levels of the water supply should be represented: from technical operators to senior managers. The full support of the leading management is essential for acceptance of the WSP, both for the work input necessary to develop it and for its subsequent day-to-day use in practice. For measures in the catchment and the water body, engagement of persons responsible for decisions in that area is required, i.e. beyond the responsibilities and decision-making authority of the water supplier. To increase the acceptance of assessments and control measures in the catchment and/or the water body it may be useful to not, or only partially, establish the team management within the water supplier.

The early involvement of the health authorities is highly recommended. The intensity of their input may vary from case to case ranging from approval of the intention to perform a WSP, to occasional invitations for consulting certain aspects and even to full team membership.

Specifically for the occurrence of cyanobacteria and cyanotoxins and their break-through in drinking water, supporting expertise in the following areas may be necessary:

  • phytoplankton ecology to understand the likelihood of cyanobacterial bloom occurrence and causes of eutrophication
  • nutrient dynamics in the catchment and the water body to set adequate targets for nutrient concentrations and nutrient loading
  • drinking-water treatment to set performance targets that ensure cyanobacterial cell and cyanotoxin removal
  • eventually also toxicology for assessing health risks if elevated cyanotoxin concentrations cannot be excluded with certainty.

This decision support tool can only outline the necessary expertise needed in your WSP team: it cannot replace the specialists. It may be useful to build a core team for the development of the WSP and to consult external specialists for the specific aspects mentioned above. Record all members of the WSP team and indicate responsibilities for parts of the risk assessment.