Low levels of per- and polyfluoroalkyl substances (PFAS) detected in drinking water in Norway, but elevated concentrations found near known sources.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous contaminants which are also found in drinking water. Concentration levels in drinking water vary widely and range from a very low contribution to total daily exposure for humans to being the major source of uptake of PFAS. PFAS concentrations in Norwegian drinking water has been rarely reported. We investigated concentrations of 31 PFAS in 164 water samples, representing both source water (i.e., before drinking water treatment) and finished drinking water. Samples were taken from 18 different water bodies across Norway. The 17 waterworks involved supply drinking water to 41 % of the Norwegian population. Only four of the waterworks utilised treatment involving activated carbon which was able to significantly reduce PFAS from the source water. Samples of source water from waterworks not employing activated carbon in treatment were therefore considered to represent drinking water with regards to PFAS (142 samples). All samples from one of the water bodies exceeded the environmental quality standard (EQS) for perfluorooctane sulfonic acid (PFOS) according to the water framework directive (0.65 ng/L). No concentrations exceeded the sum of (20) PFAS (100 ng/L) specified in the EU directive 2020/2184 for drinking water. Several EU countries have issued lower guidelines for the sum of the four PFAS that the European Food Safety Authority (EFSA) has established as the tolerable weekly intake (TWI) for PFOS, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS). Denmark and Sweden have guidelines specifying 2 and 4 ng/L for the sum of these PFAS. Only one of the 142 drinking water samples exceeded the Danish TWI and contained a sum of 6.6 ng/L PFAS. A population exposure model, for individuals drinking water from the investigated sources, showed that only 0.5 % of the population was receiving PFAS concentrations above the Danish limit of 2 ng/L.

Natural hazard risk analysis in the framework of water safety plans.

The available literature on natural hazard risk analysis focused on the implementation of water safety plans (WSPs) is surprisingly quite poor, despite the significant increase in the number and severity of disasters and adverse effects on drinking water supply systems generated by natural hazards. At the same time, WSPs that conveniently account for natural hazards with a comprehensive approach 'from source to tap' are still scarce as they typically occur at larger spatial scales and adequate prevention, mitigation and adaptation require efficient inter-institutional collaborations. The aim of this paper is to highlight the main bottlenecks for water utilities to include natural hazards in the development of their WSPs. The research adopted a stakeholders-oriented approach, involving a considerable number of water utilities (168), water sectoral agencies (15) and institutions (68) across the Adriatic-Ionian Region through a stepwise process that generated joint SWOT analysis, the development of a decision support system (DSS) focused on WSPs procedures and tabletop exercises. The final outcomes generated strategic documents (REWAS - Adrion Road map for resilient water supply) that highlighted the necessity for efficient cross-sectoral and inter-institutional cooperation in the development of well-founded and robust WSPs to address natural hazard risk analysis for water supply systems (DWSS).

Screening for 26 per- and polyfluoroalkyl substances (PFAS) in German drinking waters with support of residents.

The occurrence of per- and polyfluoroalkyl substances (PFAS) in water cycles poses a challenge to drinking water quality and safety. In order to counteract the large knowledge gap regarding PFAS in German drinking water, 89 drinking water samples from all over Germany were collected with the help of residents and were analyzed for 26 PFAS by high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The 20 PFAS recently regulated by sum concentration (PFAS∑20), as well as six other PFAS, were quantified by targeted analysis. In all drinking water samples, PFAS∑20 was below the limit of 0.1 µg/L, but the sum concentrations ranged widely from below the limit of quantification up to 80.2 ng/L. The sum concentrations (PFAS∑4) of perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorononanoate of 20 ng/L were exceeded in two samples. The most frequently detected individual substances were PFOS (in 52% of the samples), perfluorobutanesulfonate (52%), perfluorohexanoate (PFHxA) (44%), perfluoropentanoate (43%) and PFHxS (35%). The highest single concentrations were 23.5 ng/L for PFHxS, 15.3 ng/L for PFOS, and 10.1 ng/L for PFHxA. No regionally elevated concentrations were identified, but some highly urbanized areas showed elevated levels. Concentrations of substitution PFAS, including 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate and 2,2,3-trifluor-3-[1,1,2,2,3,3-hexafluor-3-(trifluormethoxy)propoxy]-propanoate (anion of ADONA), were very low compared to regulated PFAS. The most frequently detected PFAS were examined for co-occurrences, but no definite correlations could be found.

Pesticides and their metabolites in European groundwater: Comparing regulations and approaches to monitoring in France, Denmark, England and Switzerland.

Pesticides, i.e. plant protection products (PPP), biocides and their metabolites, pose a serious threat to groundwater quality and groundwater dependent ecosystems. Across large parts of Europe these compounds are monitored in groundwater to ensure compliance with the European Water Framework Directive (WFD), the Groundwater Directive (GWD) and Drinking water Directive (DWD). European regulation concerning the placing of PPP on the market includes groundwater monitoring as a higher tier of the regulatory procedure. Nevertheless, the lists of compounds to be monitored vary from one directive to another and between countries. The implementation of monitoring strategies for these directives and other national drivers, differs across Europe. This is illustrated using case studies from France, Denmark (EU member states), England (part of the EU up to January 2020) and Switzerland (associated country). The collection of data (e.g. monitoring design and analytical approaches) and dissemination at national and European level and the scale of data reporting to EU is country-specific. Data generated by the implementation of WFD and DWD can be used for retrospective purposes in the context of PPP registration whereas the post-registration monitoring data generated by the product applicants are generally only directly available to the regulators. This lack of consistency and strategic coordination between thematic regulations is partly compensated by national regulations. This paper illustrates the benefits of a common framework for regulation in Europe but shows that divergent national approaches to monitoring and reporting on pesticides in groundwater makes the task of assessment across Europe challenging.

Assessment of leakage management in small water supplies using performance indicators.

The revision of the Drinking Water Directive (DWD), which the process of consultation by the European Parliament is coming to the end, includes a commitment for all Member States to assess the level of water leakage. The overarching aim of this action is to reduce water loss through leaks. In regard to this, use of performance indicators as suitable to enable assessment of water utility performance with regard to leakage reduction, including impacts on environment and cost-efficiency, is recommended. The paper provides results from water losses evaluation with the set of performance indicators (PI), considering dependence on the availability of resources and specific operating conditions. An analysis of different PI that are necessary to evaluate in most of leakage reduction methods was conducted considering step-by-step approach. Furthermore, the most relevant data for leakage analysis and management on a network level was determined. Presented PI can be used to improve leakage management of small water supply system. Similarly as in the Deming cycle, the described tool provides for planning activities, executing activities in accordance with the plan, checking the degree of execution of objectives included in the plan, and on the basis of conducted analyses and lessons learned, the so-called improvement. The results of the analysis lead to the conclusion that through a comprehensive, systematically improved strategy, the high effectiveness of the system could be reach. The reliable monitoring does not have to be based on advanced technological methods, which are often unavailable for small water supply system, due to high investment and operating costs. The results indicate that integrated IT systems, as SCADA, might not be directly beneficial to water loss management in small networks with moderate leakage levels.

Towards the revision of the drinking water directive 98/83/EC. Development of a direct injection ion chromatographic-tandem mass spectrometric method for the monitoring of fifteen common and emerging disinfection by-products along the drinking water supply chain.

According to the recent proposal released by the European Commission for the revision of the 98/83/EC Directive, water suppliers will be requested to monitor the nine bromine- and chlorine congeners of haloacetic acids, HAAs, as well as the oxyhalides chlorite and chlorate, as disinfection by-products (DBPs) originated during the potabilization process. In this work, we propose a direct-injection method based on ion chromatography and mass spectrometric detection for the determination of the mentioned DBPs as well as bromate (already included in the 98/83/EC), implemented also for the following emerging HAAs monoiodo-, chloroiodo- and diiodo-acetic acids. The method was optimized to include the fifteen compounds in the same analytical run, tuning the chromatographic (column and gradient) and detection conditions (suppression current, transitions, RF lens settings and collision energies). To avoid matrix effect and to manage the instrumental conditions, optimization was performed directly in drinking water matrix. The method quantitation limits satisfy the new limits imposed by the future directive and range from 0.08 µg/L (monobromoacetic acid) to 0.34 µg/L (trichloroacetic acid). The performance of the method was checked along different strategic sampling points of three potabilization plants serving the city of Turin (Italy), including intermediate treatments and finished waters. Recovery was checked according to the ±30% limit of acceptability set by EPA regulations. The effect of disproportionate concentrations of chlorite and chlorate in respect to HAAs on HAA signals was studied; this aspect is underestimated in literature. The method is routinely applied by the potabilization plant of the city of Turin to confirm the effectiveness of all control measures in abstraction, treatment, distribution and storage. This study represents the first example in Italy of development and use of a cutting-edge technique for HAAs analysis along the potabilization processes.

A brief overview on radon measurements in drinking water.

The aim of this paper is to present information about currently used standard and routine methods for radon analysis in drinking waters. An overview is given about the current situation and the performance of different measurement methods based on literature data. The following parameters are compared and discussed: initial sample volume and sample preparation, detection systems, minimum detectable activity, counting efficiency, interferences, measurement uncertainty, sample capacity and overall turnaround time. Moreover, the parametric levels for radon in drinking water from the different legislations and directives/guidelines on radon are presented.

New perspectives in monitoring drinking water microbial quality.

The safety of drinking water is evaluated by the results obtained from faecal indicators during the stipulated controls fixed by the legislation. However, drinking-water related illness outbreaks are still occurring worldwide. The failures that lead to these outbreaks are relatively common and typically involve preceding heavy rain and inadequate disinfection processes. The role that classical faecal indicators have played in the protection of public health is reviewed and the turning points expected for the future explored. The legislation for protecting the quality of drinking water in Europe is under revision, and the planned modifications include an update of current indicators and methods as well as the introduction of Water Safety Plans (WSPs), in line with WHO recommendations. The principles of the WSP approach and the advances signified by the introduction of these preventive measures in the future improvement of drinking water quality are presented. The expected impact that climate change will have in the quality of drinking water is also critically evaluated.