Drinking water quality · 2024
· Verified
What's in Boulder, CO tap water
40 contaminants were measured in the Boulder, CO water system's 2024 annual report. Each is shown below against its federal limit — 4 sit at or above that limit.
- Reporting year
- 2024
- Contaminants measured
- 40
- Over federal limit
- 4
- Approaching the limit
- 0
- Worst contaminant
- PFOS
- Service area
- CO
8.3× the limit
state-level CCR
At or above the federal limit
- PFOSPFAS ("forever chemicals") · Reported level0–33 ng/Llimit 4 ng/L · 8.3× the limit
- Perfluorohexanesulfonic acidPFAS ("forever chemicals") · Reported level0–26 ng/Llimit 10 ng/L · 2.6× the limit
- PFOAPFAS ("forever chemicals") · Reported level9.4 ng/Llimit 5.1 ng/L · 2.4× the limit
- ChloramineDisinfectants · Reported level0.2–4.66 mg/L
Where your water comes from · EPA SDWIS
Boulder, CO buys its drinking water from BOULDER CITY OF.
Source
0sources
Treatment
0treatment plants
Distribution
0storage units
Also buys water from BOULDER CITY OF.
Source: EPA SDWIS facilities inventory. Methodology.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Treatment technique violationHealth-based1 violation on record · most recent Nov 2018resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 0–33 ng/LReported levelSD Formation Wells 1 - 11 | 4 ng/LMCL | At or above the limit |
+By source (6)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, National City Well 3 +3 more
| |||
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 0–26 ng/LReported levelSD Formation Wells 1 - 11 | 10 ng/LMCL | At or above the limit |
+By source (6)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, National City Well 3 +3 more
| |||
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 9.4 ng/LReported levelSystem-wide | 5.1 ng/LNL | At or above the limit |
+By source (6)— Treated¹ Sweetwater Authority Drinking Water, SD Formation Wells 1 - 11, National City Well 3 +3 more
| |||
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 0–11 ng/LReported levelSD Formation Wells 1 - 11 | None set | Detected — no federal limit |
+By source (6)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, Lake Skinner Outlet (Aqueduct) +3 more
| |||
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 0–4.6 ng/LReported levelTreated¹ Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
+By source (6)— Treated¹ Sweetwater Authority Drinking Water, National City Well 2, National City Well 4 +3 more
| |||
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | 0–7.7 ng/LReported levelTreated¹ Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
+By source (6)— Treated¹ Sweetwater Authority Drinking Water, SD Formation Wells 1 - 11, National City Well 2 +3 more
| |||
| Perfluoropentanoic acidPerfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' | 0–7.3 ng/LReported levelTreated¹ Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
+By source (3)— Treated¹ Sweetwater Authority Drinking Water, SD Formation Wells 1 - 11, Lake Skinner Outlet (Aqueduct)
| |||
| PFAS | 0–2.6Reported levelSD Formation Wells 1 - 11 | None set | Detected — no federal limit |
+By source (6)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, National City Well 2 +3 more
| |||
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | 0–15 ng/LReported levelSD Formation Wells 1 - 11 | None set | Detected — no federal limit |
+By source (3)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, Lake Skinner Outlet (Aqueduct)
| |||
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia. | 0.2–4.66 mg/LReported levelTreated1 Sweetwater Authority Drinking Water | None set | At or above the limit |
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0–956 ug/LReported levelTreated1 Sweetwater Authority Drinking Water | None set | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 0–11.1 pCi/LReported levelSD Formation Wells 1 - 11 | 15 pCi/LMCL | Within the limit |
+By source (6)— SD Formation Wells 1 - 11, Lake Skinner Outlet (Aqueduct), National City Well 4 +3 more
| |||
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 0.6–1.4 pCi/LReported levelSD Formation Wells 1 - 11 | 5 pCi/LMCL | Within the limit |
+By source (6)— SD Formation Wells 1 - 11, Sweetwater Reservoir, National City Well 2 +3 more
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | 4.7–7.4 pCi/LReported levelSD Formation Wells 1 - 11 | None set | Detected — no federal limit |
+By source (3)— SD Formation Wells 1 - 11, Lake Skinner Outlet (Aqueduct), Sweetwater Reservoir
| |||
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 0–8.5 pCi/LReported levelSD Formation Wells 1 - 11 | 20 pCi/LMCL | Detected — no federal limit |
+By source (6)— SD Formation Wells 1 - 11, Lake Skinner Outlet (Aqueduct), Sweetwater Reservoir +3 more
| |||
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 32.1 ug/LRunning annual avgSystem-wide | None set | Within the limit |
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 39.7 ug/LRunning annual avgSystem-wide | None set | Within the limit |
| Chlorite | 0.02–0.426 mg/LReported levelTreated1 Sweetwater Authority Drinking Water | 1 mg/LMCL | Within the limit |
| ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade. | 130–4306 ug/LReported levelTreated1 Sweetwater Authority Drinking Water | 800 ug/LNL | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SeleniumA trace element from natural deposits and industrial discharge. | 0–19 ug/LReported levelSD Formation Wells 1 - 11 | None set | Within the limit |
+By source (7)— SD Formation Wells 1 - 11, National City Well 4, Lake Skinner Outlet (Aqueduct) +4 more
| |||
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | 0–3.4 ug/LReported levelSD Formation Wells 1 - 11 | None set | Within the limit |
+By source (7)— SD Formation Wells 1 - 11, Sweetwater Reservoir, Lake Skinner Outlet (Aqueduct) +4 more
| |||
| CopperA metal that enters water from corroding household plumbing. | 0.313 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 3 ug/L90th percentileAt the tap | None set | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.1–0.2 mg/LReported levelSD Formation Wells 1 - 11 | 2 mg/LMCL | Within the limit |
+By source (7)— SD Formation Wells 1 - 11, National City Well 2, National City Well 4 +4 more
| |||
| AluminumA common element sometimes used as a treatment coagulant. | 0–70 ug/LReported levelSweetwater Reservoir | None set | Detected — no federal limit |
+By source (7)— Sweetwater Reservoir, Lake Skinner Outlet (Aqueduct), National City Well 4 +4 more
| |||
| BoronA naturally occurring element from rock and soil. | 0.08–0.54 mg/LReported levelSD Formation Wells 1 - 11 | 1 mg/LNL | Detected — no federal limit |
+By source (7)— SD Formation Wells 1 - 11, Treated¹ Sweetwater Authority Drinking Water, National City Well 3 +4 more
| |||
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 0–0.4 ug/LReported levelTreated Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
+By source (7)— Treated Sweetwater Authority Drinking Water, SD Formation Wells 1 - 11, National City Well 2 +4 more
| |||
| LithiumA naturally occurring element found in some groundwater. | 0–13.6 ug/LReported levelTreated¹ Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
| ManganeseA naturally occurring metal from soil and rock. | 0–10 ug/LReported levelTreated1 Sweetwater Authority Drinking Water | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 3–6 mg/LReported levelSystem-wide | None set | Detected — no federal limit |
| Vanadium | 14–19 ug/LReported levelNational City Well 2 | 50 ug/LNL | Detected — no federal limit |
+By source (7)— National City Well 2, National City Well 4, Treated¹ Sweetwater Authority Drinking Water +4 more
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.27 NTUReported levelTreated Sweetwater Authority Drinking Water | None set | Within the limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 2.9–12 mg/LReported levelLake Skinner Outlet (Aqueduct) | None set | Detected — no federal limit |
+By source (2)— Lake Skinner Outlet (Aqueduct), Sweetwater Reservoir
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.5–0.9 mg/LReported levelTreated Sweetwater Authority Drinking Water | 4 mg/LMCL | Within the limit |
+By source (7)— Treated Sweetwater Authority Drinking Water, SD Formation Wells 1 - 11, National City Well 3 +4 more
| |||
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0–1 mg/LReported levelSD Formation Wells 1 - 11 | 10 mg/LMCL | Within the limit |
+By source (7)— SD Formation Wells 1 - 11, Lake Skinner Outlet (Aqueduct), National City Well 2 +4 more
| |||
| BromideA naturally occurring salt found in source water. | 81–420 ug/LReported levelLake Skinner Outlet (Aqueduct) | None set | Detected — no federal limit |
+By source (2)— Lake Skinner Outlet (Aqueduct), Sweetwater Reservoir
| |||
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium | 0–1 ug/LReported levelSystem-wide | None set | Within the limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0Reported levelNational City Well 3 | None set | None detected |
+By source (8)— National City Well 3, National City Well 4, SD Formation Wells 1- 11 +5 more
| |||
| Cryptosporidium | 0–3Reported levelSweetwater Reservoir | None set | Detected — no federal limit |
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 3Reported levelNational City Well 2 | None set | Detected — no federal limit |
+By source (8)— National City Well 2, National City Well 3, National City Well 4 +5 more
| |||
Source: Boulder, CO's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
People also ask about Boulder, CO's water
+Is Boulder, CO tap water safe to drink in 2024?
The 2024 Consumer Confidence Report for the Boulder, CO water utility lists 4 contaminants at or above the federal limit: PFOS, Perfluorohexanesulfonic acid, PFOA, and Chloramine. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Boulder, CO tap water?
40 contaminants were measured in Boulder, CO's 2024 Consumer Confidence Report, spanning metals, pfas ("forever chemicals"), and disinfection byproducts. 14 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Boulder, CO tap water?
4 contaminants in Boulder, CO's 2024 report sit at or above the federal limit: PFOS (8.3× the limit); Perfluorohexanesulfonic acid (2.6× the limit); PFOA (2.4× the limit); Chloramine (1.2× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Boulder, CO tap water?
The contaminant with the highest measured value relative to its federal limit in the 2024 report is PFOS, at 8.3× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Boulder, CO's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Boulder, CO's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.
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