By the time a contaminant becomes regulated, most utilities are already racing the clock: treatment systems designed, funding secured, equipment procured, customers informed, all within compliance deadlines measured in months. The Suffolk County Water Authority (SCWA) decided years ago that it would rather prepare before regulations arrived than scramble after they did.

"We don’t stop looking once we find the solution."

That line from SCWA Chief Engineer Tim Kilcommons, PE, sums up how one of the nation’s largest groundwater utilities approaches emerging contaminants. Speaking during the AWWA ACE26 panel discussion “Utilizing Lessons from PFAS to Prepare for What’s Next,” Kilcommons walked through how SCWA built a long-term strategy around early monitoring, pilot testing, infrastructure planning and funding, well before regulations forced its hand.

“What can we do to meet that standard today?” Kilcommons recalled asking his team as PFAS regulations evolved. “Can we actually get to all the sites that need treatment right away? Are we going to be able to procure that many GAC systems and build them?”

Understanding the scale

SCWA’s proactive approach starts with the size of the system it has to protect. The utility serves 1.2 million people through 400,000 service connections, making it one of the largest groundwater suppliers in the country, and this year marks its 75th anniversary. It’s a not-for-profit public benefit corporation that runs entirely on rate revenue and a small amount of cell-tower income, with no tax dollars or private investors involved.

Every drop comes out of the ground, in one of the more expensive parts of the country to buy electricity, so pumping alone is a major cost driver. SCWA operates roughly 640 wells, about 590 of them active at any time, feeding water through some 240 pump stations. Seventy storage tanks hold nearly 74 million gallons, and more than 6,000 miles of water main and 36,000 fire hydrants make up the distribution system. Average daily production runs about 220 million gallons; summer irrigation pushes peak-day demand to roughly 530 million gallons. Kilcommons compares SCWA’s scale to New York City’s, which relies mainly on surface water: different source, similar size.

For a utility that large, waiting for a rule to be finalized before acting isn’t realistic.

Investing in knowledge first

SCWA’s first investment wasn’t treatment equipment, it was information. The authority runs what Kilcommons calls the largest groundwater laboratory in the country: last year, staff analyzed more than 95,000 water samples and ran over 195,000 analytical tests, seven days a week, year-round.

The lab also looks well past what’s required. “We’re testing for 390 compounds, over 230 more than we’re required to,” Kilcommons said. “We also test at a higher frequency. Our in-house standards are often tougher than what is required if we’re acting at an earlier time.” He’s also careful not to let that vigilance tip into alarm: two-thirds of SCWA’s wells need no filtration at all, a fact he uses to reassure customers that the utility isn’t treating every well like a crisis.

Getting ahead of PFAS

SCWA began testing for PFOA and PFOS in 2013, seven years before New York set maximum contaminant levels of 10 parts per trillion for each compound. When the EPA later proposed a stricter 4-ppt standard, SCWA’s engineers didn’t ask how much time was left. They asked how to meet it immediately.

The answer combined engineering and operations: SCWA rapidly expanded its use of granular activated carbon (GAC) while taking a handful of the highest-level wells offline where that was operationally feasible, enough to bring the utility into compliance with the proposed federal limit before it was even enforceable.

Rather than standardizing on the first product that worked, SCWA tested coconut-based carbon, an enhanced coconut carbon and bituminous carbon before settling on bituminous as the workhorse. A trailer-mounted GAC unit, built around two eight-foot-diameter vessels, treated a high-priority well while a permanent facility was designed, then moved on to the next site once construction caught up. Ion exchange resin became a second tool: at sites with no sewer access or high groundwater, where GAC’s backwashing needs are a real problem, resin can be the better fit. Sites with multiple contaminants tend to stay on GAC, since it treats a broader range at once.

That same instinct for testing before committing carries into design. SCWA’s engineers lean on 3D modeling to walk operators and mechanics through a project before it’s built, and the feedback isn’t always gentle. “It’s amazing, even with experience, how often a field operator will take a look at it 30 seconds and take something that you’re so proud of and just immediately reduce it to, ‘This is not going to work at all. This is going to be in my way. That’s going to be in my way. I need this. I need that,’” Kilcommons said. “It’s good feedback. It’s a little humbling, but it’s part of the process.”

Applying the same playbook to 1,4-dioxane

PFAS wasn’t SCWA’s first early mover. The utility volunteered to test for 1,4-dioxane in 2003, piloted treatment in 2011, and built New York’s first full-scale advanced oxidation process (AOP) pilot in 2016, followed by the state’s first full-scale AOP system in 2018, two years ahead of New York’s MCL for the contaminant. SCWA now runs 19 AOP systems using ultraviolet light and hydrogen peroxide to destroy 1,4-dioxane down to non-detect.

Even where an AOP system isn’t yet in place, SCWA won’t let a well run over the MCL: it pulls carbon offline instead, despite the cost. “It’s incredibly inefficient treating 1,4-D, but it does do it for a while,” Kilcommons said. “Changeouts on carbon are not cheap anymore. It’s costing us over $90,000 now for 40,000 pounds of bituminous to be exchanged, and that includes the disposal of the old.” For utilities trying to size up their own exposure, that single changeout is a useful yardstick.

“We don’t stop looking once we find the solution,” Kilcommons said of the broader mindset. “There are plenty of people out there who are trying to find that better mousetrap all the time, and we want to hear about those things. We want to test them.”

What preparedness costs

Kilcommons was unusually candid about the dollar figures involved. SCWA now spends more than $3 million a year on activated carbon alone, and the PFAS treatment program is still growing. “We’re already spending over $3 million a year on carbon, and we’re not done building them,” he said. To stretch that budget, SCWA works with university and industry partners to extend carbon life through reactivation, which lets it reuse roughly 80% of existing media and guards against a carbon market that’s tightening as more utilities install GAC nationwide.

Capital spending tells a similar story. At the time of the panel, SCWA had 15 AOP systems on order, 20 GAC systems just bid, nine treatment buildings waiting on regulatory sign-off, and 91 more AOP and GAC systems planned. It has secured about $42 million in grant funding so far. But grants and litigation recoveries don’t move fast enough to fund construction on their own. “You can’t wait for that,” Kilcommons said. “You have to start implementing. You have to start moving on treatment.” To bridge the gap, SCWA added a $20-per-quarter treatment surcharge for customers while it continues to pursue grants and cost recovery through litigation.

Prioritizing risk

With hundreds of wells and a long list of contaminants, SCWA doesn’t rank projects by contaminant level alone. “We developed a priority ranking system,” Kilcommons explained. “That might be not just based on the level of contaminant at a site.” A smaller well feeding a pressure zone with little backup can outrank a larger well surrounded by redundancy, since losing it would matter more operationally.

Looking beyond the treatment plant

Kilcommons’ clearest message may have been that utilities shouldn’t have to shoulder emerging contaminants alone. “We’re trying as hard as we can to shift the conversation,” he said. “We want to shift the conversation from the water supplier always being the one over the last line of defense to move towards eliminating these contaminants before they enter the aquifer.” He added: “We’re willing to do our part to clean the water. We know that’s what we have to do. It’s our mission. But we shouldn’t be the first and last line of defense. We should be the last line of defense.”

That philosophy now shapes how SCWA engages with development reviews, pushing county regulators and developers toward advanced wastewater treatment before contaminants ever reach the aquifer, rather than only reacting once they show up in a well. “They’ll pick up the phone and call us,” Kilcommons said. “They’re not always easy conversations, but we’re happy to talk.”

A roadmap for what's next

Looking ahead, Kilcommons wants SCWA to lean harder on outside partnerships with universities, consultants and manufacturers, retain the engineers it has trained, and keep dedicated pilot sites for apples-to-apples testing of new technologies. Procurement stays flexible on purpose: SCWA acts as its own general contractor on many projects, spreading work across multiple annual contracts rather than one vendor, which limits risk and cuts out markup.

Few utilities will match Suffolk County’s scale, laboratory or capital budget. But the underlying approach travels: gather data before regulation requires it, test technologies before a deadline forces a choice, and build the funding and staffing plan before the need becomes urgent. As SCWA’s experience shows, the work that determines whether a utility is ready for the next emerging contaminant usually starts years before that contaminant gets a federal standard.

This piece was created from the panel discussion transcript with the help of generative AI tools and edited by our content team for clarity and accuracy.