Water safety plans

The implementation of a Water Safety Plan (WSP) is required for all water systems by the Decree of the Ministry of Health of 14.06.2017, in implementation of European Union Directive 2015/1787, which endorsed the WSP methodology developed by the World Health Organisation (WHO). The aforementioned Directive 1787 amends the annexes of the European Drinking Water Directive 98/83/EC, which is currently being revised by the European Parliament and the Council. It will make WSPs mandatory and the current draft provides for a six-year implementation period.

The WSP approach is to prevent and reduce the risks inherent in the drinking water service, assessing dangerous events along the entire water supply chain including collection, treatment and distribution to the user meter. The risk is calculated according to the severity and probability of a pollution event or water shortage. Based on this assessment, the following are defined: actions to mitigate risks, monitoring systems, operating procedures under normal and emergency conditions, the water quality control plan, the methods for informing the public and the competent authorities, etc. WSPs must also be constantly updated to take into account plant development, changes in the regulatory environment and climate and environmental changes. Finally, the implementation of WSPs must be carried out according to internationally recognised methodologies developed by the WHO. In Italy, the Istituto Superiore di Sanità (ISS) has introduced WHO guidelines and will therefore have to approve WSPs.


For Acea Ato 2, in the first two years the implementation of the water safety plans (WSPs) will affect the water system supplied by the new water treatment plant of the Tiber located in Grottarossa and the water network of the City of Rome and the Vatican, now supplied by the Paolo Aqueduct, with non-potable water taken from the Tiber. The assessment of the health risks of the latter system, which is not drinkable, is included in the safety plan and is interconnected thereto since the Paolo Aqueduct will no longer be supplied by water from the Tiber but by the treated wastewater from the COBIS treatment plant.
Starting in the second half of 2019, the WSP will be launched for the water system supplied by other aqueducts, primarily serving Rome and Fiumicino.
In 2018 the WSP team was set up with the participation of Acea staff and representatives of the bodies concerned. A web platform was created with these same bodies on which the documents produced
are published and a web/GIS environment where the data of the plants covered by the WSP are collected. Moreover, the risk assessment of the water system supplied by the new Grottarossa plant was carried out and shared with the authorities.
To this end, plant inspections were carried out and checklists drawn up in accordance with WHO guidelines.
Finally, Acea Ato 2 established partnerships with major operators in the water sector to share experiences and best practices.

At Acea Ato 5 and Gesesa, before drafting the Water Safety Plans (WSPs), several employees attended the “National Training Course for team leaders for the implementation of Water Safety Plans (WSPs)” organised by the ISS and the Ministry of Health.