Drinking water
For environmental monitoring professionals, few areas show this shift more clearly than PFAS, TFA, pharmaceuticals, microplastics and pesticide residues.
These substances are technically demanding to analyse and in some cases the accredited laboratory capacity is still limited.
In this interview, Craig Jarvis, Quality and Office Manager at Wessex Water Scientific Centre, discusses what the recast Drinking Water Directive and revised Urban Wastewater Treatment Directive mean in practice for monitoring teams, where the main analytical gaps remain and why implementation will depend on realistic timelines, specialist capability and robust data quality.
The most significant change introduced by the recast Drinking Water Directive is the requirement for mandatory PFAS monitoring, which represents a major technical challenge for the industry. PFAS analysis is highly specialised, requiring contamination-controlled laboratory environments, advanced instrumentation and experienced analysts. It cannot be implemented quickly or within standard laboratory settings. As a result, we currently subcontract this work, as only a limited number of laboratories can meet the required standards.
A key difficulty is the need to analyse a large suite of PFAS compounds (e.g. ~48 for DWI) within a single sample. This increases analytical complexity and leads to a higher likelihood of quality control failures, particularly relating to contamination and recovery. Consequently, repeat analysis rates are high, significantly impacting operational costs and turnaround times.
In parallel, the revised Urban Wastewater Treatment Directive places greater emphasis on micropollutants, including PFAS. This extends the challenge beyond monitoring to include future expectations around removal and treatment, further increasing technical complexity and cost across the water sector.
Monitoring contaminants such as PFAS, TFA, pharmaceuticals, microplastics and pesticide residues across different water matrices is highly complex and challenging, due to both analytical requirements and matrix variability (e.g. raw water, drinking water, wastewater).
Each group requires specialised methods and conditions. PFAS and TFA require ultra-trace LC-MS/MS with strict contamination control. Pharmaceuticals require complex organic extraction and targeted analysis. Microplastics require physical and spectroscopic techniques. Pesticides rely on multi-residue screening methods.
In practice, no single workflow can cover all parameters. Subcontracting to ALS, for example, requires four separate analytical test suites and three different bottle types, reflecting differing preservation and analytical needs.
This complexity is compounded by the current lack of capability in the UK: no laboratories currently analyse TFA or microplastics to a UKAS-accredited standard, further limiting options and increasing reliance on specialist providers.
Across different matrices, issues such as matrix interference, contamination risk and variable recoveries make consistent data quality difficult to achieve, leading to higher rates of repeat analysis, increased costs and longer turnaround times.
Analytical methods for contaminants such as PFAS, TFA, pharmaceuticals, microplastics and pesticide residues are not yet fully mature or standardised, and there remain significant gaps across the sector.
While some methods, particularly for PFAS and certain pesticides, are relatively well developed, they still present challenges around consistency, contamination control, and reproducibility, particularly at the low detection limits now required. For other contaminants, the situation is less advanced. In the UK, there are currently no UKAS-accredited methods for TFA or microplastics, meaning that results cannot always be generated within a fully accredited framework, which limits confidence and comparability.
In addition, methods are often laboratory-specific, with variations in extraction techniques, calibration approaches, and reporting limits. This lack of harmonisation leads to difficulties when comparing data across laboratories or monitoring programmes.
The absence of fully standardised methods also contributes to higher uncertainty, increased quality control failures, and repeat analysis, particularly for complex matrices such as wastewater. Overall, although capability is developing rapidly, the analytical landscape remains inconsistent and evolving, and cannot yet be considered fully robust or standardised.
The updated framework introduces several key sampling, detection-limit, and quality assurance challenges that both laboratories and field teams must manage carefully.
From a sampling perspective, contamination control is critical, particularly for substances such as PFAS, which are ubiquitous in the environment. This requires use of specialist bottles and equipment (e.g. avoiding fluorinated materials); strict control of sampling procedures, transport, and storage conditions; increased risk of false positives if protocols are not rigorously followed
In terms of detection limits, many contaminants must now be measured at ultra-trace levels (ng/L or lower). Achieving this reliably requires highly sensitive instrumentation and well-controlled methods. However, matrix effects – especially in wastewater – can significantly impact detection capability and data quality.
From a quality assurance perspective, laboratories must manage complex multi-analyte methods with higher uncertainty; greater likelihood of QC failures (e.g. blanks, recoveries, calibration); and increased need for repeat analysis and data validation.
Together, these factors place a much greater emphasis on robust QA systems, method validation and clear data acceptance criteria to ensure results are reliable and defensible.
Yes. The new EU rules do clearly point toward greater use of advanced analytical and monitoring techniques, but this transition is still developing and not yet fully embedded.
The increased focus on emerging contaminants and ultra-low detection limits (e.g. PFAS) is already driving wider adoption of more sensitive techniques such as high-resolution mass spectrometry (HRMS) and advanced LC-MS/MS methods. These technologies allow for improved detection at very low concentrations, broader compound coverage and retrospective data analysis
There is also growing interest in non-target and suspect screening approaches, particularly to identify previously unmonitored contaminants. However, these methods are not yet standardised and are currently more suited to investigative or research-based applications rather than routine compliance monitoring.
From a sampling perspective, there is increasing use of automated and high-frequency sampling, particularly for wastewater and surface water, to better capture variability and pollution events.
Overall, the direction of travel is clearly toward more advanced, data-rich monitoring approaches, but significant barriers remain around standardisation, accreditation, cost, and operational practicality, meaning widespread routine adoption is still evolving rather than fully established.
To prepare for implementation of the new EU requirements, regulators, utilities and monitoring suppliers need to take a proactive, coordinated approach, recognising that capability, standards and infrastructure are still evolving.
Regulators should focus on providing clear, realistic guidance on expectations, timelines and acceptable uncertainty; greater standardisation of methods and reporting frameworks; and recognition of current limitations, particularly where accredited methods do not yet exist (e.g. TFA, microplastics).
Utilities need to prioritise early planning and risk assessment for emerging contaminants such as PFAS; strengthening supplier and laboratory assurance, particularly where analysis is subcontracted; ensuring robust data governance, validation processes and audit trails; building internal awareness of the cost, complexity and limitations of advanced monitoring.
Monitoring suppliers and laboratories should focus on developing and validating robust, reproducible methods; expanding specialist capacity to meet increasing demand; and improving quality control processes to reduce repeat analysis
Across all parties, there is a need to accept that implementation will be progressive rather than immediate, with collaboration essential to ensure that monitoring is both technically achievable and scientifically defensible.
IET 36.3 May
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