Is Durham Tap Water Safe to Drink?
Durham's tap water met every federal limit in its 2025 report. The highest routine reading was Haloacetic Acids (HAA5) at 82% of its limit — 49 ppb against a 60 ppb limit.
Two analytes sit above half of a federal limit: Haloacetic Acids (HAA5) at 82% and Total Trihalomethanes (TTHM) at 70% — both disinfection byproducts, which form when disinfectants react with organic matter in the water. Neither exceeded its limit, but they are the numbers to watch in this report.
Key figures — 2025 report
- Haloacetic Acids (HAA5)
- 49 ppb against a 60 ppb limit
- Lead, 90th percentile
- Non-detect — highest single sample 3 ppb (action level: 15 ppb)
- Contaminants tested
- 19 — none above a federal maximum
Serving 333,490 people, PWSID NC0332010.
Lead pathway
Where lead enters Durham's water
Lead is measured where it matters: at customers' taps. Durham's most recent lead and copper compliance round ran from June to September 2025. The 90th percentile was Non-detect against a 15 ppb federal action level, and 0 samples exceeded that level.
"Non-detect" is the report's own wording: the 90th-percentile result sat below the laboratory's reporting limit, and the highest single sample in the round measured 3 ppb against the 15 ppb action level. Because the percentile is not a number, no percent-of-limit can honestly be computed for it — so this page does not show one.
Complete lead tap sampling data is available on request at WQReport@DurhamNC.gov.
The utility's own report attributes lead at the tap to service lines and household plumbing — corrosion of the pipes between the main under the street and the faucet — not to Lake Michie and Little River Reservoir or the treatment plants.
Is my service line lead?
How to find out whether your service line is lead
The utility has been working to identify service line materials throughout the system and has prepared an inventory of all service lines.
Durham maintains a service line inventory at www.DurhamNC.gov/5184.
Residents concerned about lead can contact the City of Durham at 984-242-3012 to have their water tested. The report does not state whether this is free.
What the utility recommends at home
- Flush. Before drinking tap water, flush your pipes for several minutes by running the tap, taking a shower, doing laundry or running a load of dishes.
- Filter. Use a filter certified by an American National Standards Institute accredited certifier to reduce lead in drinking water.
- Identify and remove. Identify and remove lead materials within your home plumbing.
Full contaminant results
Every detected contaminant in Durham's 2025 report
Nineteen contaminants appear in the detected-results tables. Seven were detected at one or more treatment plants; none exceeded a federal maximum contaminant level. These tables sit on top of a broader program: the utility routinely monitors more than 150 contaminants under federal and state law.
Durham maintains two residual disinfectants in the system — chloramines and chlorine — each reported against the same 4 ppm maximum residual disinfectant level. Each has its own row in the table below.
System-wide results
| Contaminant | Your water | Limit | % of limit | Range |
|---|---|---|---|---|
| Haloacetic Acids (HAA5) | 49 ppb (highest LRAA) | 60 ppb | 82% | 13 – 48 |
| Total Trihalomethanes (TTHM) | 56 ppb (highest LRAA) | 80 ppb | 70% | 26 – 54 |
| Chloramines | 1.5 ppm (annual average) | 4 ppm | 38% | 0.01 – 3 |
| Chlorine | 0.63 ppm (annual average) | 4 ppm | 16% | 0 – 2.04 |
| Fluoride | 0.7 ppm | 4 ppm | 18% | 0.67 – 0.77 |
| Turbidity (highest single measurement) | 0.1 NTU | Treatment technique violation if turbidity exceeds 1 NTU | — | — |
| Total Organic Carbon removal ratio | 1.58 ratio | Treatment technique violation if the removal ratio RAA falls below 1.00 and alternative compliance criteria are not met | — | 1.43 – 1.65 |
Haloacetic Acids (HAA5): The report lists a highest LRAA of 49 ppb with a range of 13–48 ppb. The LRAA exceeds the stated range maximum. Both figures are reproduced as printed.
Total Trihalomethanes (TTHM): The report lists a highest LRAA of 56 ppb with a range of 26–54 ppb. The LRAA exceeds the stated range maximum. Both figures are reproduced as printed.
Total Organic Carbon removal ratio: Reported as the lowest running annual average removal ratio. Above 1.00 indicates compliance.
Tested for and not detected
Eleven more analytes were monitored and came back below the laboratory reporting limit. The "<" values are the reporting limits themselves — the utility's instruments found nothing above them.
See all eleven not-detected analytes and their reporting limits
| Contaminant | Result | Limit (MCL) |
|---|---|---|
| Nitrate (as Nitrogen) | <1.0 ppm | 10 ppm |
| Nitrite (as Nitrogen) | <0.1 ppm | 1 ppm |
| Arsenic | <0.005 ppm | 0.01 ppm |
| Barium | <0.025 ppm | 2 ppm |
| Cadmium | <0.001 ppm | 0.005 ppm |
| Chromium | <0.02 ppm | 0.1 ppm |
| Mercury | <0.0002 ppm | 0.002 ppm |
| Atrazine | <0.1 ppb | 3 ppb |
| Dalapon | <0.1 ppb | 200 ppb |
| Simazine | <0.1 ppb | 4 ppb |
| E. coli | 0 positive or present samples | 0 presence/absence |
Secondary (aesthetic) parameters
These are measured against secondary standards — federal guidelines for taste, odor and staining, not health-based limits.
| Parameter | Average | Range | Guideline (SMCL) |
|---|---|---|---|
| Sodium | 33.9 ppm | 20.2 – 42.2 | None set |
| Sulfate | 56.5 ppm | 47.2 – 71.7 | 250 ppm |
| pH | 7.5 pH units | 7.4 – 7.5 | 6.5 – 8.5 pH units |
| Iron | <0.053 ppm | <0.050 – <0.063 | 0.3 ppm |
| Manganese | <0.013 ppm | <0.010 – 0.02 | 0.05 ppm |
| Nickel | <0.01 ppm | — | None set |
PFAS and other unregulated contaminants
Durham sampled for unregulated contaminants four times in 2025 (11 February 2025, 19 May 2025, 12 August 2025 and 10 November 2025). The utility's framing: "Unregulated contaminants are those for which EPA has not established drinking water standards." Four compounds were detected:
| Compound | Average | Range | Finalized federal MCL |
|---|---|---|---|
| PFBS | 5.9 ppt | 3.1 – 7.7 ppt | None |
| PFOS | 5.6 ppt | 4.6 – 7.2 ppt | 4 ppt |
| PFOA | 3.8 ppt | 2.8 – 5.7 ppt | 4 ppt |
| PFBA | 2.2 ppt | 2 – 3.5 ppt | None |
Where that leaves Durham: PFOS averaged 5.6 ppt and PFOA reached 5.7 ppt at the top of its range — above the 4.0 ppt federal Maximum Contaminant Levels the EPA finalized in April 2024. Those limits are final but not yet enforceable: systems are not required to meet them until 26 April 2029 (the EPA has proposed an exemption pathway to 2031, not finalized as of August 2026), so these results do not violate any current federal drinking water standard. At the same time, the EPA's health-based goal for PFOA and PFOS is zero, and water above the future limits will likely need treatment or new sources before the deadline. PFBS and PFBA carry no individual federal limit: PFBS counts only toward a mixture hazard index that the EPA has proposed to rescind — Durham's 5.9 ppt contributes a negligible share of it — and PFBA is not federally regulated in drinking water.
Regulatory status verified against EPA sources on 29 August 2026.
Complete unregulated-contaminant results are available on request at WQReport@DurhamNC.gov.
Where your water comes from
Lake Michie and Little River Reservoir to your tap
Durham draws its drinking water from Lake Michie and Little River Reservoir.
Treatment happens at the Williams Water Treatment Plant (1405 Hillandale Road) and the Brown Water Treatment Plant (1615 Infinity Road). The report publishes all results system-wide rather than per plant.
Some of this water was purchased from Town of Cary
Durham also purchased water from Town of Cary (system 03-92-020) during the 2025 report year. Depending on where you live and when, the water at your tap may have come partly from Town of Cary's system rather than from Durham's own plants — and Town of Cary's water is tested and reported separately. Town of Cary publishes its own water quality results at carync.gov.
Source water assessment
The North Carolina DEQ Public Water Supply Section, Source Water Assessment Program (SWAP) rated Durham's sources on a "Higher", "Moderate" and "Lower" scale:
| Source | Susceptibility rating | Assessment date |
|---|---|---|
| Lake Michie | Higher | 2020 |
| Little River Reservoir | Higher | 2020 |
What that rating means — and does not mean: A susceptibility rating of "higher" does not imply poor water quality, only the system's potential to become contaminated by potential contaminant sources in the assessment area. The rating combines a contaminant rating (number and location of potential contaminant sources within the assessment area) with an inherent vulnerability rating for the watershed.
Full assessment reports: ncwater.org/?page=600, or (919) 707-9098 / swap@deq.nc.gov.
Source protection programs
- Watershed Protection Program: Buffers the source water from development around the reservoirs and upstream.
- Long Range Water Resources Plan: A roadmap to 2070 forecasting future demand, outlining ways to use water more efficiently, and exploring supply options under a range of future scenarios.
What you can do
Should you filter Durham tap water?
Durham's data points at disinfection byproducts: Haloacetic Acids (HAA5) at 82% of its limit and Total Trihalomethanes (TTHM) at 70% of its limit. Both are within federal limits, but they are the highest readings in the report by a wide margin.
The relevant device for disinfection byproducts is an activated carbon filter — carbon is the standard at-the-tap treatment for trihalomethanes and haloacetic acids. Look for a filter whose certification names TTHM or disinfection byproduct reduction, and verify the claim on the certifier's listing before buying. One extra check for Durham: the system runs chloramines as well as chlorine, and chloramine is harder for a basic carbon filter to remove than free chlorine — if taste and odor matter to you, choose a filter explicitly rated for chloramine reduction.
What this data does not tell you
Every number on this page describes water at the plants, in the mains, or as a system-wide statistic. None of it was measured in your building. If you want to know about your water rather than Durham's, testing at your own tap is the only source.
Your pipes tell a different story
The data above shows what leaves the treatment plant—not what comes out of your faucet. Old pipes, lead solder, and building plumbing can add contaminants the city never tests for. Know exactly what's in your Durham tap water.
Home test kits detect lead, bacteria, pesticides, and 100+ other contaminants. Results in 5-10 business days from certified labs.
If testing does point at a specific contaminant, our filter guides cover certifications and what to verify before buying.
Frequently asked questions
Sources and methodology
Primary sources
- *2025 Annual Drinking Water Quality Report* (Consumer Confidence Report, published 30 June 2026), City of Durham Department of Water Management, PWSID NC0332010 — www.durhamnc.gov/946
- EPA Safe Drinking Water Information System (SDWIS), PWSID NC0332010
- EPA PFAS National Primary Drinking Water Regulation and related Federal Register proposals — regulatory status checked 29 August 2026
How we compiled this
We do not test water. Every figure on this page is transcribed from documents published by City of Durham Department of Water Management or the EPA, and each is attributed to the document it came from. Where two published figures disagree, we show both and say so rather than choosing one.
Lead and copper values are 90th-percentile compliance statistics from the 2025 sampling round. We state sample years next to values rather than presenting everything as current.
Author: TapWater.org Editorial Team — https://www.tapwater.org/about
Data current as of: the 2025 Consumer Confidence Report
This page presents publicly available regulatory data. It is not medical advice. Water quality varies by building and over time. For official information, contact City of Durham Department of Water Management at (919) 560-4381.
Last updated: 2026-09-11