After the March boil-water advisory, my phone didn't stop for a week.
Three months later, the calls have quieted down, but the questions haven't. People still want to know what happened, what CPW did about it, and whether it could happen again. Here's the timeline, cited from public reporting.
What Happened
On March 17, 2026, a contractor punctured the Santee Cooper main line at the Lake Moultrie Regional Water Plant. The breach interrupted the treated water supply to Summerville Commissioners of Public Works (CPW) and downstream distribution systems.
CPW issued a boil-water advisory affecting approximately 70,000 residents across Summerville, Goose Creek, and portions of Berkeley County between Moncks Corner and Goose Creek.
Who was affected:
- Summerville CPW customers (Nexton, Cane Bay, Carnes Crossroads, Foxbank, Summerville proper)
- Goose Creek city water customers
- Berkeley County portions between Moncks Corner and Goose Creek
Who was NOT affected:
- Charleston Water System customers
- Naval Weapons Station residents
The advisory was extended through at least March 18, 2026, lasting a minimum of 24 hours after the repair was completed.
The Response
CPW activated its three emergency wells, which have a combined capacity of about 5 million gallons per day (CPW's average daily demand is about 6.5 million gallons per day). The emergency wells provided supplemental supply while the main line was being repaired.
The Santee Cooper repair restored the Lake Moultrie supply, and the advisory was lifted after water quality testing confirmed the system was back to compliance.
What a Boil-Water Advisory Means
A boil-water advisory means the utility cannot guarantee the water reaching your tap meets microbiological safety standards. The standard guidance:
- Boil all water used for drinking, cooking, brushing teeth, making ice, and washing food
- Bring water to a rolling boil for at least one minute
- Bottled water is an alternative
- Water for handwashing and bathing is generally considered safe for healthy adults, but keep it out of open wounds
The advisory doesn't mean your water is contaminated. It means the utility can't confirm it isn't.
What Hasn't Changed
The March event was a physical infrastructure breach, a contractor hitting a pipe. It wasn't a chemical spill or a treatment-plant failure. The water quality before and after the breach, at the plant level, didn't change.
What hasn't changed about Summerville's water:
- **Hardness** is still about 7.2 grains per gallon
- **Disinfection** is still chlorine
- **EWG flags** still include 11 contaminants above EWG health guidelines
- **The PFAS infrastructure project** ($43.5M CPW share of $96M total) is still underway
- **Lead service lines** are still zero per CPW's completed inventory
- **The source** is still Lake Moultrie surface water via Santee Cooper
The March event was an acute infrastructure disruption. The chronic water quality characteristics, hardness, disinfection byproducts, PFAS levels, are the same today as they were on March 16.
The Broader Infrastructure Question
Summerville CPW serves about 20,532 connections. The service area has grown dramatically: Berkeley County is SC's 2nd-fastest-growing county at 3.2% year-over-year, and the Cane Bay, Nexton, and Carnes Crossroads cluster has added roughly 27,000 residents since 2015.
When population grows faster than infrastructure investment, the infrastructure is running closer to capacity. The March event was a contractor error, not a capacity issue. But the 12.2% rate hike and the $96M PFAS project suggest CPW is investing in the system. Whether that investment keeps pace with the growth is a question the next decade will answer.
The Emergency Well Backup
During the advisory, CPW activated its three emergency wells, which have a combined capacity of about 5 million gallons per day. CPW's average daily demand is about 6.5 million gallons per day. That means the emergency wells cover roughly 77% of normal demand, enough to maintain basic service while the main supply was being repaired but not enough for full-capacity operations.
The emergency wells are a backup system. They exist for exactly this kind of event. But they underscore the reality that CPW's service area has grown significantly (Berkeley County adding 3.2% population per year), and the infrastructure supporting that growth has a single main supply line from Lake Moultrie.
What the Advisory Taught Homeowners
The conversations we had in the weeks after March 17 fell into three categories:
"I never thought about my water before." The advisory was the first time many Summerville residents considered where their water comes from. Lake Moultrie via Santee Cooper was an abstraction until the advisory made it concrete.
"I want a baseline." Several homeowners booked free water tests specifically to establish a post-advisory baseline. They wanted numbers they could compare to future readings if another event happens.
"What can I actually control?" The utility controls the treatment plant and the distribution mains. The homeowner controls what happens between the meter and the faucet. A whole-home conditioning system is one thing a homeowner can control. A POU RO at the kitchen tap is another. Neither would have prevented the boil-water situation (that was a distribution-level event), but both give the homeowner a layer of treatment at their own home.
What You Can Do
Whether the March advisory rattled you or you've moved on, the two actions available to you as a homeowner are:
1. Read your utility's CCR. Summerville CPW publishes an annual Consumer Confidence Report. It tells you what was measured and at what levels. The EWG profile provides a second, stricter read of the same data.
2. Test your tap. A free in-home water test gives you the numbers at your specific tap, not the utility-level averages. It's the most direct way to know what's coming through your pipes today.
FAQ: March 2026 Advisory
Could it happen again?
Infrastructure events are always possible. The March breach was a contractor error. CPW's emergency wells provide partial backup capacity. The broader question is whether the infrastructure investment keeps pace with the growth.
Is my water safe now?
CPW's water has returned to its normal quality profile and meets federal EPA standards. If you want to confirm what's at your specific tap, a free water test is the most direct way.
If You Want a Post-Advisory Baseline
Book a free in-home water test. I'll test your tap and give you a fresh set of numbers to compare against the utility-level data. If you tested before the advisory, we can compare current vs. baseline.
Call or text Jarred at (843) 302-5720, or book at prstnwtr.com/book.