Rock Hill & Fort Mill Water Quality Guide: What's in Your Tap

Where does Rock Hill's water come from?

Rock Hill draws surface water from Lake Wylie, a reservoir on the Catawba River, and treats it at its Cherry Road water filter plant using conventional treatment. The city's 2025 Rock Hill Water Quality Report says the Catawba River basin is the source and refers readers to a state source water assessment for the Catawba basin, which identifies the supply as susceptible to contaminant categories such as volatile organic compounds, petroleum products, metals, nitrates, pesticides and herbicides.

The same report lists wholesale customers: York County, the City of York, Fort Mill, Tega Cay, River Hills and the Catawba Indian Nation. A susceptibility rating describes what could affect a source, not what is in your glass today.

Who supplies Fort Mill, Tega Cay, Lake Wylie, York, Clover and Indian Land?

Several systems overlap in York and Lancaster counties, so check your water bill before you read any report. What the primary documents we opened say:

If you live in the Lake Wylie, York County or Indian Land areas, your bill tells you which utility, and that utility's report is the one that matters. Reports for York County's West and East systems are separate documents.

Is there chloramine in Rock Hill or Fort Mill water?

The reports we read list chlorine, not chloramine. Rock Hill's 2025 report tables chlorine (as Cl2) at 0.74 to 2.12 ppm against a limit of 4.0 ppm, along with chlorine dioxide and chlorite results. Tega Cay's 2024 report and both York County 2025 reports also list chlorine as the disinfectant, and none of them mentions chloramine.

Rock Hill's report also lists fluoride at 0.64 ppm. If you moved from a city that uses chloramine, do not assume the same filter advice applies; check the disinfectant line in your own utility's report. If your report does list chloramine, see our guide on removing chloramine, since standard carbon filters handle chlorine and chloramine differently.

What has been found about PFAS in the Catawba and local utility water?

Three sourced facts, kept separate so they are not blended into one scary or reassuring headline:

• Utility results. Rock Hill's 2025 report and York County's East report show testing for two unregulated PFAS, PFHxA and PFPeA. York East lists PFHxA at a 4.0 ppt average and PFPeA at 4.6 ppt average. Rock Hill's report does not list PFOA, PFOS, PFHxS, PFNA, HFPO-DA (GenX) or PFBS. Tega Cay's 2024 report lists the same two compounds.
• River data upstream. North Carolina's 2022 emerging compounds report found PFAS in Catawba basin reservoirs, with PFOS detected at 11 of 12 sites, usually near the 2.0 ng/L reporting limit. At the Catawba River at South Belmont it listed PFPeA 2.4, PFOS 2.2 and PFHxA 2.1 ng/L. That report did not include Lake Wylie and did not compare results with EPA limits.
• Federal rules. EPA's PFAS drinking water page says PFOA and PFOS limits remain 4.0 ppt, and that a May 2026 proposal would uphold them and allow systems to request until 2031 to comply. The same proposal would rescind the limits for PFHxS, PFNA, GenX and the hazard index. These are proposals, not final.

Because the utility reports we read do not list PFOA or PFOS results, we cannot say how your water compares to the 4.0 ppt limit. Ask your utility directly. For background, see our PFAS explainer.

How do you read your annual water quality report?

1. Find your supplier on your bill, then open that utility's report: Rock Hill 2025, York County West, York County East or Tega Cay 2024. Fort Mill posts its report on its annual water quality report page.
2. Check the disinfectant row: chlorine or chloramine, and the range.
3. In the contaminant table compare the highest or average level to the limit (MCL). Disinfection byproducts such as TTHM and HAA5 are reported as running annual averages. Rock Hill listed a highest TTHM average of 52 ppb against an 80 ppb limit.
4. Find the unregulated contaminants (UCMR) section for PFAS. Note units: ppt and ng/L are the same.
5. Read the lead and copper table, noting the year sampled and the number of sites over the action level.
6. Read the violations section. York County's 2025 reports list notice and monitoring violations, such as failing to test or report in specific periods. These are paperwork or testing violations, not necessarily contaminant exceedances, but ask the utility if you want details.

Hardness is listed as 18 to 35 ppm in the Tega Cay and York County reports, which is on the soft side. Rock Hill's own table layout was unclear in our copy, so check the original.

Why do some Rock Hill-area homeowners still filter?

• Taste and smell. Chlorine and seasonal surface-water changes are common reasons for a pitcher or under-sink filter.
• PFAS peace of mind. With limits in flux and incomplete local results, some households want a certified reduction claim.
• Infants, immune concerns or older plumbing. Ask your doctor for health-specific guidance.
• Distance from the plant. Water that sits in long runs of pipe can taste different at the tap than at the treatment plant.

Soft water means a softener is rarely needed here. See our comparison of whole-house filters versus softeners.

What about lead pipes and plumbing?

Rock Hill's 2025 report states the system has no known lead service lines, with a 90th percentile lead result of 2 ppb (action level 15 ppb) from 2023 sampling. York County's East report lists a 90th percentile of 3.000 ppb from 2024 sampling, and its table shows 2 samples over the action level while listing no violation. Tega Cay's 2022 sampling found no lead detected at the 90th percentile.

Even without lead lines, EPA notes that brass faucets and lead solder can contribute, and that service lines are more common in homes built before 1986. EPA suggests flushing, using cold water for drinking and cooking, and using filters certified for lead. Testing is the only sure way to know.

What if you are on a private well in York or Lancaster County?

Private wells are not covered by utility reports or federal drinking water rules, so testing is up to you. SCDES offers kits through regional offices and health departments, one for coliform bacteria and one for metals and minerals, described on its well water testing page.

SCDES's 2025 PFAS presentation reported detections in private wells statewide (118 samples, with PFOA detected in 45 and PFOS in 24), though it did not single out York County. Treat that as a reason to consider testing, not a prediction for your well. See our well water guide for treatment options.

Rock Hill-area situations: if this, then that

• If you are on city or wholesale water and mostly dislike the taste: start with an NSF/ANSI 42 certified filter.
• If PFAS is your concern: ask your utility for PFOA and PFOS results, then look for a filter or RO system whose certification lists PFOA/PFOS reduction.
• If you live in a pre-1986 home: have lead tested and ask about your service line material.
• If you are on a well: test for bacteria and metals first, then choose treatment based on results.
• If you are unsure who serves you: call the utility numbers printed in the reports (York County: 803-628-3211).
• If you just moved from a chloraminated city: confirm your new disinfectant before buying a filter.

When should you test your water?

• Before buying any treatment system, so you buy for a real problem.
• After a plumbing repair, new fixtures, or a change in taste, smell or color.
• Private wells: yearly for bacteria is a common recommendation; confirm intervals with SCDES.
• If you have infants or someone is pregnant and you have older plumbing.

Use a certified lab. You can also request a free local water report to go with your lab results.

Which filter fits which concern?

NSF explains these standards on its water treatment standards page. For pricing context see whole-house filter costs and whether you need a whole-house filter.

What should you ask a water treatment installer?

1. Which lab test is the recommendation based on?
2. Which NSF/ANSI standard and which contaminants does the exact model list?
3. What does maintenance cost per year, and how often are cartridges or membranes replaced?
4. How much water does it waste, and what does it do to pressure?
5. Is a warranty or service agreement in writing?
6. Will they test before and after installation?