Building a PFAS reduction plan that works: Managing future PFAS levels at Illinois wastewater facilities

By the time wastewater treatment plant managers reach the reduction phase of the Illinois National Pollutant Discharge Elimination System (NPDES) permit, they already know two things: PFAS are present, and they are coming from somewhere upstream.

The previous inventory process helps identify potential contributors. The next step is turning that information into a practical, defensible reduction plan that lowers PFAS loading before it reaches your plant.

A reduction initiative is not a one-size-fits-all process. It is a working strategy that evolves as you learn more about your system, your contributors and the effectiveness of your efforts. When done well, it becomes one of the most valuable tools you have for meeting permit requirements and protecting your facility. Here, we'll look at how to build a PFAS reduction plan that actually works. 

What story is the inventory telling?

Your PFAS inventory is the backbone of your reduction plan. It tells the story of the industrial users, commercial operations and hauled waste sources most likely to be contributing PFAS to your treatment plant.

The inventory also gives you a sense of scale. It helps facilities understand flows, operations, and potential PFAS sources within the collection system.

The goal is to understand not just who is contributing, but how and why. That means reviewing survey responses, Safety Data Sheet (SDS) information, industrial processes and any sampling data. In many cases, you are already aware of the highest-risk contributors from pretreatment programs. In others, the inventory uncovers new or unexpected sources.

Once you have a clear picture of contributors, you can begin prioritizing. Facilities with known PFAS-related activities, such as metal finishing, textile treatment, chemical manufacturing, landfills, often require additional coordination because of their higher potential PFAS use.

Build a plan that fits each contributor

A strong PFAS reduction initiative recognizes that every contributor is different. Some have the resources and technical capacity to make operational changes quickly. Others need more guidance. The most effective reduction efforts offer a mix of best practices tailored to each facility's operations.

Common reduction strategies include:

• Substituting PFAS-containing products with PFAS-free alternatives.
• Improving housekeeping and spill prevention.
• Optimizing water use.
• Decontaminating or replacing equipment.
• Increasing employee training and awareness.

For some contributors, the first step is simply understanding where PFAS might be entering their processes. Many facilities use PFAS-containing products without realizing it because the compounds are listed under proprietary names or buried in SDS documentation. Helping users identify these products can be a particularly impactful early action.

Other contributors might need support evaluating PFAS-free alternatives or adjusting their operations to reduce potential discharges. Some might require additional sampling to pinpoint sources within their facility.

The key is collaboration. Reduction efforts work best when contributors understand the expectations and feel supported in meeting them.

Use quarterly retesting to measure progress

The NPDES permit requires quarterly influent and effluent sampling, and those results are more than a reporting obligation. They are your feedback loop.

Quarterly data helps you see whether PFAS loading is trending up, down or holding steady. It also helps you evaluate whether reduction efforts are working or whether additional actions are needed. Changes in overall influent concentrations can help indicate whether reduction efforts across the collection system are improving conditions over time.

Retesting also helps you identify changes in industrial activity. PFAS use can shift quickly as businesses adopt new products or processes. Regular sampling ensures your reduction plan stays grounded in real conditions rather than assumptions.

Keep the plan alive with annual updates

Just like the PFAS inventory, the reduction initiative is not a one-and-done requirement. Annual updates are essential. They document progress, refine strategies and incorporate new information from contributors, sampling results and operational changes.

These updates also demonstrate to the Illinois Environmental Protection Agency that you are actively managing PFAS reduction, not simply meeting minimum requirements. A well-maintained reduction initiative shows you understand your system, are engaged with your contributors and are committed to reducing PFAS loading over time.

While creating a PFAS reduction plan can feel daunting, it becomes manageable when approached step by step. Start with the contributors identified in your inventory. Then work collaboratively with those contributors to develop strategies that reflect their operations. Use quarterly sampling to measure progress. Update the plan annually to keep it relevant.

Fehr Graham's wastewater experts can help you better understand your PFAS inventory and create a detailed, comprehensive reduction plan that safeguards potable water sources. 

Learn more about PFAS as it pertains to wastewater by reading about NPDES permitting, PFAS inventory creation and PFAS source identification.