Webinar Recap: An Operator's Guide to Verifying Unknown Service Lines
LSL Inventory
LSL Verification
The Lead and Copper Rule Improvements (LCRI) baseline service line inventory deadline is November 1, 2027. For a lot of utilities, the number that matters most right now is how many "unknown" service lines are still sitting on that list.
A recent webinar on verifying those unknowns, presented in partnership with the National Rural Water Association (NRWA), brought in 120Water's Josh Hawley, Director of Water Utility Services, and Maddie Brogan, Director of Client Experience, to walk through the playbook operators are using to close that gap, drawing on real field experience.
Here are some of the highlights, including a case study from Ocean Isle Beach, North Carolina, that showed just how fast that gap can close when the plan is right.
Know Where You Actually Stand
Before any digging happens, the first move is an honest gut check. Pull up whatever you submitted back in 2024 and compare it to what you know today.
Have you logged materials during meter swaps, main breaks, or service line repairs since then? If the answer is "not really," you're not alone.
Most utility teams admit their historical records, as-built maps included, aren't much to work with. Tap cards without any real information on them are common, too.
None of that is anyone's fault. Nobody was keeping these records with this rule in mind, because this rule didn't exist yet.
This just means record keeping starts now, for good. This inventory push is only the first of several LCRI initiatives that will lean on the same data. Whatever you document today pays off again down the road.
Work the Low-Hanging Fruit First
Once you know where you stand, the goal is minimizing how often a shovel actually hits the ground, since that's by far the most expensive way to identify a service line. The playbook starts with the cheapest options and works up from there.
Age reviews and records reviews cost nothing and clear out a chunk of unknowns immediately. Anything built after the lead ban went into effect is done. From there, statistical analysis is the biggest lever for utilities that have already inspected some lines and have reasonable confidence they're a non-lead system.
If field inspections so far show no lead and no galvanized requiring replacement (GRR), a state-approved plan lets you inspect a representative 20% sample of remaining unknowns, spread across build decades and neighborhoods rather than one street. If that pool comes back clean, the other 80% can be classified as non-lead, with a smaller validation sample required down the line to confirm the method held up.
However, if you find any lead or GRR in that sample, the math changes. You can finish the sample pool since you're already out inspecting anyway, but you can no longer classify the rest as non-lead based on an assumption that's now been proven wrong.
That's where predictive modeling takes over. The tool assigns a probability to each remaining line, drawing correlations from everything already in your inventory. It's front-loaded work, with a heavy first-round verification list, but accuracy climbs fast once the model is calibrated. Utilities typically want to see accuracy in the 95% range before relying on it.
Both predictive modeling and statistical analysis vary by state, so check what your regulator accepts before committing to either one.
Decide Who's Doing the Digging
Contractor or in-house isn't just a budget question.
Plumbers are great at plumbing, but that doesn't automatically mean they're equipped to identify buried materials in a way that holds up to state and EPA scrutiny.
Look for a track record with this specific kind of work, and get clear upfront on what support your team needs to provide, from knowing where meter boxes sit to supplying tools. Payment terms matter too: some contractors charge by location, others by the dig, and a statement of work that spells out who handles what gets rid of a lot of confusion later.
If you're keeping the work in-house, the same questions apply: who's trained, who owns resident communication, and who's responsible for restoration once a hole needs to be filled back in.
Get the Field Basics Right
In the field, small habits determine whether a photo actually holds up as documentation.
Daylight enough of the pipe to see it clearly, remove debris, and use the flash on your camera even in daylight. Label which side is the system side and which is the customer-owned side. Then, show the scratch or magnet test if one confirmed the material. Document any connectors you run into as well, even though nobody is digging specifically to go find them.
The Payoff
Ocean Isle Beach had 708 unknown service lines and a three-person team, including the superintendent, which made digging that many holes on their own a non-starter.
Because the system had no history of lead or GRR, statistical analysis was the right fit. Their inspection pool dropped to 142 sites, a contracted crew finished the fieldwork in about three days, and the result was zero unknowns remaining.
Not every system will move that quickly, but it's a real example of how much the right method can shrink the workload.
Watch the Full Session
Our full walkthrough goes deeper into validation pools, tricky GRR determinations, and the connector questions utilities are asking most. Watch the complete session to get the full field playbook to ensure you're on track for LCRI compliance.
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