Navigating the Middle Ground on PFAS

From Scientific Promise to Operational Decision-making

Across the water sector, few challenges illustrate today’s decision-making tension as clearly as PFAS.

On one side, the pace of scientific research is acceleration. Universities, pilot programs, and research institutions are generating new insights into detection, removal, and destruction pathways at a remarkable rate. On the other, regulatory pressure is tightening, costs are rising, carbon impacts are under scrutiny, and public trust is increasingly fragile.

Between those forces sit a much harder question for utilities: what can actually be done now, credibly, affordably, and at scale, without closing off better options for the future?

Observing the decision landscape

In public communications from Waternet, a distinction can be observed between three interconnected dimensions of the PFAS challenge:

• Research and technology development, including laboratory work, pilots, and longer-term innovation pathways
• External pressure, such as regulation, cost, carbon performance, and public confidence
• Near-term operational decision-making, where utilities must act within existing system, regulatory and resource constraints

These dimensions are not in competition. Rather they reflect the reality that utilities must translate scientific progress and policy ambition into operational decisions, often before all uncertainties have been resolved.

Decision-making under uncertainty

PFAS-related decisions are not being made in a stable environment. Regulatory thresholds are evolving. Scientific understanding continues to develop. Long-term performance data remains limited. Yet utilities are being asked to make investments with operational and financial consequences that may last decades.

In this context, the challenge is not whether to act, but how to structured decisions in a way that acknowledges uncertainty, makes assumptions explicit, and avoids locking systems into inflexible pathways.

Relying solely on early-stage research may overstate readiness for deployment, while defaulting to familiar treatment approaches without system-level consideration can introduce cost, carbon, or operational constraints that are difficult to unwind as standards change. 

What is increasingly needed is structured support for prioritisation and sequencing, enabling confident decisions even where conditions continue to evolve.

From technology scanning to decision support

In its work with Waternet, Isle was asked to support a specific decision challenge: how to translate existing knowledge and innovation into clear, defensible near-term actions, while remaining aligned with longer-term system objectives.

The focus was not to replace or evaluate ongoing research programmes, nor to draw comparisons between innovation pathways. Instead, the work examined technologies that are already sufficiently mature to be considered for near-term application, alongside the constraints utilities face when integrating them into live systems.

The output combined technology insight with a structure decision approach, forming the basis of a strategic framework developed by Isle and subsequently refined in collaboration with Waternet. This framework is currently under review as part of Waternet’s broader strategic transition, rather than being fully implemented. As articulated in Waternet’s public materials:

“The work was intended to form a practical and strategic decision-making framework, supporting the identification of effective, affordable, and sustainable PFAS measures, both now and towards 2050.” – Waternet

That distinction matters. The work does not represent a finalised or deployed strategy, but rather a structured approach designed to support ongoing decision-making as Waternet continues to assess and evolve its direction

Technology lists answer the question “What exists?” Decision frameworks help utilities answer a harder question “What should we do next, given our specific system, constraints, and risk profile?”

Managing trade-offs explicitly

One insight that often emerges from decision-led analysis is that, in many contexts, no single option simultaneously maximises cost efficiency, carbon performance, treatment efficacy, resilience and operational simplicity.

As a result, utilities are frequently required to manage trade-offs across treatment stages, cost centres, emissions profiles, and residual streams. These trade-offs are not inherently negative, but they benefit from being identified and assessed explicitly, rather than emerging unintentionally through isolated decisions. 

Addressing PFAS purely as a treatment optimization challenge, without consideration upstream source control, regulatory alignment, or system-wide implications, can increase the risk of unintended outcomes. A more integrated perspective supports clearer sequencing and more robust decision-making.

This is not an argument against action. It is an argument for sequencing and integration.

PFAS management as a system-level challenge

PFAS management often requires coordination across multiple parts of the water system. Responsibilities and impacts can span:

• Source protection and permitting
• Policy and regulatory engagement
• Treatment strategy and operational resilience
• Cost recovery and carbon performance
• Long-term adaptability as standards and expectations evolve

This does not diminish to importance of unit process innovation or optimization. Rather, it highlights the value of situating technical advances within a broader system context, so that performance gains align with governance, operations, and long-term resilience objectives.

What this means for utilities globally

While Waternet’s context is Dutch, the challenge it highlights is global. Utilities in North America and elsewhere are facing the same convergence of tightening standards, public scrutiny, and incomplete certainty.

The lesson is not that utilities should wait. It is that they should act with intent, using decision frameworks that make trade-offs explicit, preserve future flexibility, and align near-term actions with long-term system goals.

In practice, that means asking different questions:

• What decisions must be made before regulation fully settles – and which can wait?
• Where does early action reduce long-term regret, even if it is not optimal today?
• How do treatment choices interact with carbon targets, operating models, and public expectations?

These are not questions research alone can answer. They sit squarely in the middle ground between science and operations.

Holding the middle ground

The space between scientific promise and operational reality is rarely comfortable. It is defined by partial information, competing objectives, and pressure to move faster than certainty allows.

But it is also where leadership shows up, not by claiming perfect answers, but by making decisions that are transparent, defensible, and adaptable.

As PFAS regulation accelerates worldwide, utilities that invest in decision capability, not just technology, will be better positioned to respond, not only to PFAS, but to the next emerging contaminant that follows the same path.