What was found in Dubuque's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 1500 µg/L 15% of the EPA limit 10000 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 7800 µg/L — NORTH END MOBILE HOME PARK · 40 people · 2019 | 8/16 | SYR4 |
| Copper | 44.995 µg/L 3.5% of the EPA limit 1300 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 1888 µg/L — TERRACE HEIGHTS · 548 people · 2018 | 15/16 | SYR4 |
| Fluoride | 600 µg/L 15% of the EPA limit 4000 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2012 | 12/16 | SYR4 |
| Barium | 20.1 µg/L 1% of the EPA limit 2000 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2012
Highest in the city: 398 µg/L — TABLE MOUND PARK · 455 people · 2014 | 10/16 | SYR4 |
| TTHM | 57 µg/L 71% of the EPA limit 80 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 8/16 | SYR4 |
| Total Haloacetic Acids (HAA5) | 18.295 µg/L 30% of the EPA limit 60 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 53.28 µg/L — TABLE MOUND PARK · 455 people · 2019 | 6/16 | SYR4 |
| Monochloroacetic Acid | 5.535 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 46.88 µg/L — TABLE MOUND PARK · 455 people · 2019 | 7/16 | SYR4 |
| Chloroform | 39 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 8/16 | SYR4 |
| Lead | 17.28 µg/L 115% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 14/16 | SYR4 |
| Bromodichloromethane | 13 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 8/16 | SYR4 |
| Dichloroacetic Acid | 11.78 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 6/16 | SYR4 |
| Dibromochloromethane | 6.304 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 7.736 µg/L — TABLE MOUND PARK · 455 people · 2019 | 7/16 | SYR4 |
| Bromoform | 1 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 6.7675 µg/L — TABLE MOUND PARK · 455 people · 2019 | 4/16 | SYR4 |
| Dibromoacetic Acid | 2.08 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019
Highest in the city: 4.748 µg/L — TABLE MOUND PARK · 455 people · 2019 | 6/16 | SYR4 |
| Combined Radium (-226 And -228) | 3.6 pCi/L 72% of the EPA limit 5 pCi/L Highest in the city: ACE MOBILE HOME PARK · 32 people · 2018 | 12/16 | SYR4 |
| Trichloroacetic Acid | 3.148 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2019 | 8/16 | SYR4 |
| Chromium | 2.1 µg/L 2.1% of the EPA limit 100 µg/L Highest in the city: GREEN BRIER SUBDIVISION · 35 people · 2014 | 2/16 | SYR4 |
| Monobromoacetic Acid | 1.27 µg/L No EPA limit set Highest in the city: TABLE MOUND PARK · 455 people · 2019 | 1/16 | SYR4 |
| Thallium, Total | 0.5000 µg/L 25% of the EPA limit 2 µg/L Highest in the city: LORE OAKS HOMEOWNERS ASSN. · 64 people · 2013 | 1/16 | SYR4 |
| Atrazine | 0.3000 µg/L 10% of the EPA limit 3 µg/L Highest in the city: HICKORY ACRES · 115 people · 2018 | 1/16 | SYR4 |
| Simazine | 0.1500 µg/L 3.8% of the EPA limit 4 µg/L Highest in the city: HICKORY ACRES · 115 people · 2018 | 1/16 | SYR4 |
| Pfba | 0.0130 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2024 | 1/16 | UCMR-5 |
| PFOA | 0.0051 µg/L No EPA limit set Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2024 | 1/16 | UCMR-5 |
| Lead | 0.0050 mg/L 33% of the EPA limit 0.0150 mg/L Main supplier: DUBUQUE WATER WORKS · 59,667 people · 2023 | 16/16 | LCR |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Dubuque
| Supplier | Population served |
|---|---|
| DUBUQUE WATER WORKS | 59,667 |
| ALPINE PARK | 932 |
| TERRACE HEIGHTS | 548 |
| TABLE MOUND PARK | 455 |
| SUPER 20 MOBILE HOME COURT | 236 |
| HICKORY ACRES | 115 |
| STAR WATER | 110 |
| QUALITY WATER, INC. #2 (K-L) | 70 |
| LORE MOUND MOBILE HOME PARK | 68 |
| LORE OAKS HOMEOWNERS ASSN. | 64 |
| GAVIN ESTATES | 52 |
| NORTH END MOBILE HOME PARK | 40 |
| SHAGBARK ESTATES | 38 |
| GREEN BRIER SUBDIVISION | 35 |
| REGENCY WEST SUBDIVISION | 34 |
| ACE MOBILE HOME PARK | 32 |
Frequently asked questions about Dubuque tap water
Is Dubuque tap water safe to drink?
EPA testing detected 24 contaminants in the water serving Dubuque. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Dubuque?
16 public water suppliers report drinking-water monitoring for Dubuque, Iowa to the EPA. Each is listed above with its population served.
What contaminants are in Dubuque's water?
The contaminants EPA monitoring detected in Dubuque include Nitrate, Copper, Fluoride, Barium, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.