Rockbridge S/D
What EPA’s and CDC’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 1,042 people
- Connections
- 410
- Water source
- Groundwater
- Based in
- Knightdale, NC
- County
- Wake
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Uranium, above the legal limit. 15 health-based violations since 2016.
What handles itWhat was found
Lead and copper: EPA SDWIS monitoring periods ending 2011 to 2028.
Uranium, haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic and nitrate: North Carolina’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.
Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from Sept. 25, 2012 to Jan. 3, 2017. Newer results are in the utility’s annual water quality report.
Above the legal limit1
Uranium
Comes from the source
10.8ppb
Highest yearly average, 2020 to 2023
2023: not found
Averaged by year, the highest was 10.8 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2023, the latest year on file, it wasn’t found. EPA judges this limit at each sampling point, and recorded violations for uranium at this utility in 2025 and 2026. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 121 ppb, in 2015, and EPA recorded violations in 2013, 2015 and 2016.
What handles it
- NSF/ANSI 58 look for “Uranium”
Above the health goal1
Lead
Comes from pipes, often your own
7.8ppb
90th percentile, 2026 to 2028
In the latest period, 9 in 10 homes sampled were at or below 7.8 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.
What handles it
- NSF/ANSI 53 look for “Lead Reduction”
- NSF/ANSI 58 look for “Lead Reduction”
Below EPA’s limits3
Fluoride
Forms or is added in treatment
0.37ppm
Highest yearly average, 2012 to 2017
Averaged by year, the highest was 0.37 ppm, in 2017, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Haloacetic acids (HAA5)
Forms or is added in treatment
3.0ppb
Highest yearly average, 2020 to 2023
Averaged by year, the highest was 3.0 ppb, in 2023, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 4.2 ppb, in 2014.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
2.0ppb
Highest yearly average, 2020 to 2023
Averaged by year, the highest was 2.0 ppb, in 2023, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.5 ppb, in 2018.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Nitrate
What handles it
A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”
- NSF/ANSI 53
Claim: Lead Reduction
For: Lead
- NSF/ANSI 58
Claims: Uranium, Lead Reduction
For: Uranium, Lead
At the tap, or for the whole house?
Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.
Filters with those claims on a certifier’s listing
Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money
Brita Tahoe Pitcher with Elite Filter (OB60, OB06)
Pitcher
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 13, 2026
- IAPMO listing:NSF/ANSI 53checked Oct. 13, 2026
Certified for: Lead
Brita Everyday Pitcher with Elite Filter (OB46, OB06)
Pitcher
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 13, 2026
Certified for: Lead
PUR PLUS 11-Cup Pitcher (PPT111W)
Pitcher
- NSF listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
Certified for: Lead
ZeroWater 10 Cup Pitcher (ZP-010)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53checked Oct. 4, 2026
Certified for: Lead
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Combined Radium (-226 and -228) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2026 to Sept. 30, 2026 | 7.0 PCI/L | Addressed |
| Gross alpha radiation (excluding radon and uranium) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2026 to Sept. 30, 2026 | 480 PCI/L | Addressed |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2026 to Sept. 30, 2026 | 74.2 PCI/L | Addressed |
| Gross alpha radiation (excluding radon and uranium) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 478 PCI/L | Archived |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 74.2 PCI/L | Archived |
| Combined Radium (-226 and -228) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 6.0 PCI/L | Archived |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 55.6 PCI/L | Archived |
| Gross alpha radiation (excluding radon and uranium) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 359 PCI/L | Archived |
| Gross alpha radiation (excluding radon and uranium) | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2025 to Dec. 31, 2025 | 356 PCI/L | Archived |
| Combined Uranium | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2025 to Dec. 31, 2025 | 55 PCI/L | Archived |
| Lead and Copper Rule Revisions | The required inventory of lead service lines was not completed or submitted on time.EPA: LSL Inventory | Oct. 17, 2024 | — | Resolved |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2016 to Dec. 31, 2016 | 42.1 PCI/L | Resolved |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2016 to Sept. 30, 2016 | 46.1 PCI/L | Resolved |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2016 to June 30, 2016 | 77.1 PCI/L | Resolved |
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2016 to March 31, 2016 | 60.4 PCI/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 45 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Uranium, haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic and nitrate results here are North Carolina’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Rockbridge S/D’s own annual report, which it must send you every year, has newer results for those and the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; CDC’s yearly averages for North Carolina cover 2020 to 2023; EPA’s compliance samples are from Sept. 25, 2012 to Jan. 3, 2017.
Testing your own tap
The 3 labs North Carolina certifies closest to the area Rockbridge S/D serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Wake County Human Services-Public Health Ctr.
Raleigh, NC · about 5 miles
Certified for bacteria, nitrate, metals, minerals and other inorganics
NC State Lab of Public Health
Raleigh, NC · about 14 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Eurofins Built Env. Testing East - Cary
Cary, NC · about 17 miles
Certified for asbestos
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages North Carolina supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or North Carolina’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: North Carolina State Laboratory of Public Health, certified drinking water laboratories, read Oct. 11, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID NC4092073. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Uranium
- Get the utility’s own reportRockbridge S/D must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs