In Uruguay, the Regulation approved by Resolution No. 120/2018 by the Energy and Water Services Regulator (URSEA) establishes that Drinking Water Service Providers (EPSAs) must guarantee a formal verification procedure with the aim of conducting a final assessment of the global efficacy of the water safety plan, including the entire water supply chain and guaranteeing the reliability of a continuous water supply that is compatible with consumer safety objectives. The verification includes three activities that are performed simultaneously: a) verification monitoring; b) sanitary inspection, internal and external audits; and c) consumer satisfaction assessments. The sanitary inspections and internal audits aim to confirm whether the water safety plan complies with applicable requirements and ensure that water quality and risks are monitored.

According to this regulation, systems with over 20,000 inhabitants must conduct at least one internal audit annually. Systems with fewer than 20,000 inhabitants must conduct at least one sanitary inspection and one simplified internal audit annually. Without prejudice to the foregoing, these systems shall be subject to an internal audit pursuant to the schedule set forth by the EPSA, which shall contemplate a minimum of 3 annual systems by department.

The criteria, methods and frequencies that are to be adopted when conducting internal audits, in addition to report results and registry maintenance, must be defined in a documented procedure under the responsibility of the corresponding EPSA management, which is to ensure the timely adoption of any actions needed to eliminate non-conformities detected and their causes, as recorded during internal and external audits. Each action plan proposed must specify various stages of implementation and associated deadlines.

Additionally, the URSEA, as regulator, shall conduct external water safety plan audits independently of the EPSA. The URSEA may also conduct testing and analyses to verify whether the water supply is safe and complies with quality, safety and health rules, as well as other regulatory requirements.

The Regulation on the Quality of Water for Human Consumption, Supreme Decree No. 031-2010-SA, orders the Directorate of Environmental Health (DIGESA) as well as Health Offices, Regional Health Offices and Regional Health Management Boards across the country to administrate the sanitary supervision program for water distribution. Likewise, the Health Authority, SUNASS, and legally empowered municipalities, must supervise the systems of water distribution for human consumption in their jurisdiction in accordance with the provisions and sanitary requirements determined by the Regulation. In the context of these powers, sanitary inspections are delegated to the service providers, which must report on quality self-monitoring in accordance with the provisions of the same Regulation. This self-monitoring is defined as: “1. All activities performed to identify, eliminate or monitor any risk to water distribution systems, from abstraction to the point of delivery to consumers, be this a property connection,

public pool, reservoir tank pump or a point of delivery via a tanker, in order to ensure that water for consumption complies with the requirements set forth in the Regulation; 2. The verification of the efficiency and sanitary quality of distribution system components; 3. The organization of consumer claims and complaints regarding the quality of water provided or other sanitary risks generated by the distribution system, in order to adopt the corresponding corrective measures; and 4. The application of the contingency plan to ensure the quality of water for consumption in emergencies.”

The auditing of water and sanitation safety plans (WSPs) involves independent and systematic checks to confirm completeness, adequate implementation, and effectiveness.

Auditing is an integral part and core component of WSP verification (see figure), but is distinct from WSP reviews. The WSP team should undertake WSP reviews regularly, and also after incidents or ‘near misses’, to keep WSPs current and effective. WSP auditing, by comparison, should ideally be carried out by an independent person or persons not directly involved in the development and implementation of WSPs.

Although distinct, WSP review and auditing are related, in that the results of auditing should always inform WSP teams’ ongoing review process, and both activities contribute to the continuous improvement of the WSP. Auditing may also form part of drinking-water quality surveillance programmes, being continuous and vigilant public health assessments and reviews of the safety and acceptability of a drinking water supply.

The WHO guidelines for drinking-water quality (2011) recommend that surveillance programmes include WSP auditing, in addition to direct assessments of water quality.