Water Safety Plans

A supply is deemed 'safe' if it meets the relevant drinking water quality standards at the tap and 'secure' if a risk management system, a Drinking Water Safety Plan (DWSP), is in place. A DWSP identifies all potential risks to the water supply, from catchment to consumer, and mitigation measures and procedures are put in place to manage these risks. 

In 2009 the World Health Organisation (WHO) published detailed guidance on the implementation of the Drinking Water Safety Plan approach, the document is entitled "Water Safety Plan Manual: step-by-step Risk Management for Drinking Water Supplies".  The primary objective of this approach is to protect human health.  The approach applies equally to small and large drinking water supplies.

The EPA has adopted the WHO's Water Safety Plan approach (see Advice Note No 8).  The advice note is intended to give an overview of the steps involved in constructing a DWSP and an outline of what it should contain.  DWSPs are also covered in Section 10 of the EPA's 2010 Handbook for Public Water Supplies. The EPA’s Office of Radiological Protection (ORP) produced guidance for  Water Services Authorities and Water Suppliers on radiological hazards and associated risks for the purpose of developing Drinking Water Safety Plans (DWSPs) for a water supply (see Hazardous Event CO107 Guidance: Geological Characteristics Causing Contamination; Hazardous Event CO220 Guidance: Nuclear Incident Causing Contamination and Hazardous Event Guidance: Vandalism Causing Deliberate Contamination of the Water Supply – i.e. the Raw Water Source, Raw Water Storage or Treated Water in Service Reservoirs or Water Towers).

In Ireland, responsibility for the development and implementation of DWSPs for public water supplies rests with the water supplier, Irish Water. The output from the DWSP process will be used to prioritise remedial works for supplies that need it most and drive improvements in the provision of consistently safe and secure drinking water nationally.

In 2014 the EPA launched a DWSP online tool be used by Irish Water and Local Authority staff in the completion of DWSPs.  The EPA envisages that DWSPs for the eight largest public water supplies in the country will be completed first and subsequently Irish Water will complete DWSPs for all drinking water supplies in the country. 

Irish Water will take the lead in the implementation of the DWSP approach for public water supplies but it will be required to co-operate with stakeholders in the catchment including government agencies, industry, farmers, landowners, environmental non-government organisations, recreation/sporting bodies, etc.  These stakeholders will assist in the identification and mitigation of hazardous events in the catchment.  Successful engagement of such stakeholders will serve a dual role or improving raw water source protection for the supply as well as assist in meeting the Water Framework Directive requirements of maintaining or improving water quality status.

Open and transparent implementation of the DWSP approach will increase the consumer’s confidence in the water supplier and will also bring about a greater understanding and awareness amongst all stakeholders involved from source to tap in their role in the protection of our water resources and ensuring that our water supply is consistently safe to drink.

A DWSP should be constantly reviewed and updated to ensure that it delivers a safe and secure water supply.