Tap water · DC
DC Water
EPA system ID DC0000002 · serves about 632,323 people. Every US utility must publish an annual water quality report — here’s the official one (2025), and below it, our plain-English translation.
Read the official report →What DC Water found in 2025
28 detected analytes from the utility’s own annual report, hand-normalized — nothing was near or over a federal health-based limit.
| Detected | Level | Limit | % of limit | Status |
|---|---|---|---|---|
| Chlorine | 3.1 ppm | 4 ppm | 78% | Within limit |
| Total Trihalomethanes (TTHMs) | 50 ppb | 80 ppb | 63% | Within limit |
| Haloacetic Acids (HAA5) | 34 ppb | 60 ppb | 57% | Within limit |
| Perfluorooctanesulfonic acid (PFOS) | 1.1 ppt | 4 ppt | 28% | Within limit |
| Nitrate as Nitrogen | 2 ppm | 10 ppm | 20% | Within limit |
| Fluoride | 0.7 ppm | 4 ppm | 18% | Within limit |
| Lead (90th percentile) | 2 ppb | 15 ppb | 13% | Within limit |
| Perfluorooctanoic acid (PFOA) | 0.5 ppt | 4 ppt | 13% | Within limit |
| Copper (90th percentile) | 0.098 ppm | 1.3 ppm | 8% | Within limit |
| Atrazine | 0.2 ppb | 3 ppb | 7% | Within limit |
| Cyanide | 0.007 ppm | 0.2 ppm | 4% | Within limit |
| Arsenic | 0.3 ppb | 10 ppb | 3% | Within limit |
| Barium | 0.04 ppm | 2 ppm | 2% | Within limit |
| Hexafluoropropylene Oxide (HFPO) Dimer Acid and its Ammonium Salt (GenX) | 0 ppt | 10 ppt | 0% | Within limit |
| Mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS | 0 ppt | 1 ppt | 0% | Within limit |
| Perfluorohexanesulfonic acid (PFHxS) | 0 ppt | 10 ppt | 0% | Within limit |
| Perfluorononanoic acid (PFNA) | 0 ppt | 10 ppt | 0% | Within limit |
| Total Hardness | 139 ppm | — | — | No federal limit |
| Sodium | 32 ppm | — | — | No federal limit |
| Total Hardness (average detected contaminants) | 8 grains/gal | — | — | No federal limit |
| Perfluoropentanoic acid (PFPeA) | 2.7 ppt | — | — | No federal limit |
| Perfluorohexanoic acid (PFHxA) | 2 ppt | — | — | No federal limit |
| Perfluorobutanoic acid (PFBA) | 1.8 ppt | — | — | No federal limit |
| Total Coliform | 1.2 % | — | — | No federal limit |
| Perfluorobutanesulfonic acid (PFBS) | 1.1 ppt | — | — | No federal limit |
| Nickel | 0.9 ppb | — | — | No federal limit |
| Cryptosporidium | 0.29 oocysts per liter | — | — | No federal limit |
| Turbidity (highest) | 0.08 NTU | — | — | No federal limit |
Levels and limits are as printed in the utility’s report (“limit” is the EPA MCL, action level, residual limit, or secondary guideline that applies to that row; “ND” = not detected). Utilities publish these reports annually — we re-check every covered utility each July, after the federal publication deadline. Detected doesn’t mean dangerous — most detections sit far below their limits. This is education, not medical advice.
Your tap, if it were a bottle
How DC Water water stacks up against the bottled aisle
Same minerals, same units — the tap values below come from the utility’s report, placed next to the closest match in our bottled-water database.
| Mineral | Your tap | Closest bottled match |
|---|---|---|
| Sodium | 32 mg/L | San Pellegrino at 32 mg/L |
Tap values are the headline levels from the utility’s annual report (often a highest or average figure); bottled values are label- or report-derived. A closest match is a numeric comparison, not an equivalence or an endorsement.
Zip codes covered
20001 · 20002 · 20003 · 20004 · 20005 · 20006 · 20007 · 20008 · 20009 · 20010 · 20011 · 20012 · 20015 · 20016 · 20017 · 20018 · 20019 · 20020 · 20024 · 20032 · 20036 · 20037
Boundary zips partially served by other systems are deliberately unlisted — check your exact zip.