Out of 319 ZIP codes with data in Iowa, these are the highest-ranked areas for lead (ppb). See also: National Worst ZIP Codes for Lead in Water | All Iowa Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 319 |
| Highest value | 14.6 ppb |
| Median value | 2.0 ppb |
| State | Iowa |
Top 100 Worst ZIP Codes
| Rank | ZIP Code | City | State | Lead (ppb) | Safety Score |
|---|---|---|---|---|---|
| 1 | 50604 | Aplington | IA | 14.6 ppb | — |
| 2 | 50665 | Parkersburg | IA | 14.6 ppb | — |
| 3 | 50461 | Osage | IA | 11.4 ppb | — |
| 4 | 52162 | Postville | IA | 9.9 ppb | — |
| 5 | 52208 | Belle Plaine | IA | 9.8 ppb | — |
| 6 | 52101 | Decorah | IA | 9.4 ppb | — |
| 7 | 50126 | Iowa Falls | IA | 9.0 ppb | — |
| 8 | 50601 | Ackley | IA | 9.0 ppb | — |
| 9 | 52302 | Marion | IA | 8.3 ppb | 67/100 |
| 10 | 51401 | Carroll | IA | 8.0 ppb | — |
| 11 | 51652 | Sidney | IA | 7.9 ppb | — |
| 12 | 51653 | Tabor | IA | 7.9 ppb | — |
| 13 | 51654 | Thurman | IA | 7.9 ppb | — |
| 14 | 50138 | Knoxville | IA | 7.8 ppb | — |
| 15 | 50602 | Allison | IA | 7.6 ppb | — |
| 16 | 50611 | Bristow | IA | 7.6 ppb | — |
| 17 | 50636 | Greene | IA | 7.6 ppb | — |
| 18 | 51018 | Cushing | IA | 7.3 ppb | — |
| 19 | 51020 | Galva | IA | 7.3 ppb | — |
| 20 | 51025 | Holstein | IA | 7.3 ppb | — |
| 21 | 50644 | Independence | IA | 7.1 ppb | — |
| 22 | 52037 | Delmar | IA | 7.1 ppb | — |
| 23 | 52060 | Maquoketa | IA | 7.1 ppb | — |
| 24 | 50134 | Kelley | IA | 7.0 ppb | — |
| 25 | 50244 | Slater | IA | 7.0 ppb | — |
| 26 | 50801 | Creston | IA | 7.0 ppb | — |
| 27 | 50677 | Waverly | IA | 6.7 ppb | 49/100 |
| 28 | 50441 | Hampton | IA | 6.2 ppb | — |
| 29 | 50616 | Charles City | IA | 6.2 ppb | — |
| 30 | 50213 | Osceola | IA | 6.0 ppb | — |
| 31 | 50458 | Nora Springs | IA | 6.0 ppb | — |
| 32 | 50468 | Rockford | IA | 6.0 ppb | — |
| 33 | 50471 | Rudd | IA | 6.0 ppb | — |
| 34 | 50525 | Clarion | IA | 6.0 ppb | — |
| 35 | 50563 | Manson | IA | 6.0 ppb | — |
| 36 | 50575 | Pomeroy | IA | 6.0 ppb | — |
| 37 | 52632 | Keokuk | IA | 6.0 ppb | — |
| 38 | 52720 | Atalissa | IA | 6.0 ppb | — |
| 39 | 52721 | Bennett | IA | 6.0 ppb | — |
| 40 | 52747 | Durant | IA | 6.0 ppb | — |
| 41 | 52760 | Moscow | IA | 6.0 ppb | — |
| 42 | 52765 | New Liberty | IA | 6.0 ppb | — |
| 43 | 52766 | Nichols | IA | 6.0 ppb | — |
| 44 | 52778 | Wilton | IA | 6.0 ppb | 67/100 |
| 45 | 50009 | Altoona | IA | 5.6 ppb | 65/100 |
| 46 | 50171 | Montezuma | IA | 5.5 ppb | — |
| 47 | 52222 | Deep River | IA | 5.5 ppb | — |
| 48 | 52049 | Garnavillo | IA | 5.3 ppb | — |
| 49 | 52157 | Mc Gregor | IA | 5.3 ppb | — |
| 50 | 52768 | Princeton | IA | 5.2 ppb | — |
| 51 | 50054 | Colfax | IA | 5.1 ppb | 67/100 |
| 52 | 50228 | Prairie City | IA | 5.1 ppb | — |
| 53 | 50436 | Forest City | IA | 5.0 ppb | — |
| 54 | 50511 | Algona | IA | 5.0 ppb | — |
| 55 | 52001 | Dubuque | IA | 5.0 ppb | — |
| 56 | 52002 | Dubuque | IA | 5.0 ppb | — |
| 57 | 52003 | Dubuque | IA | 5.0 ppb | — |
| 58 | 52039 | Durango | IA | 5.0 ppb | — |
| 59 | 52068 | Peosta | IA | 5.0 ppb | — |
| 60 | 52172 | Waukon | IA | 5.0 ppb | — |
| 61 | 50115 | Guthrie Center | IA | 4.8 ppb | — |
| 62 | 50250 | Stuart | IA | 4.8 ppb | — |
| 63 | 52339 | Tama | IA | 4.8 ppb | — |
| 64 | 52342 | Toledo | IA | 4.8 ppb | — |
| 65 | 50660 | New Hartford | IA | 4.6 ppb | — |
| 66 | 50670 | Shell Rock | IA | 4.6 ppb | — |
| 67 | 51250 | Sioux Center | IA | 4.4 ppb | — |
| 68 | 50645 | Ionia | IA | 4.3 ppb | — |
| 69 | 50658 | Nashua | IA | 4.3 ppb | — |
| 70 | 50662 | Oelwein | IA | 4.2 ppb | — |
| 71 | 50524 | Clare | IA | 4.0 ppb | — |
| 72 | 51054 | Sergeant Bluff | IA | 4.0 ppb | 66/100 |
| 73 | 51331 | Arnolds Park | IA | 4.0 ppb | — |
| 74 | 51355 | Okoboji | IA | 4.0 ppb | — |
| 75 | 51449 | Lake City | IA | 4.0 ppb | — |
| 76 | 52228 | Fairfax | IA | 4.0 ppb | — |
| 77 | 52240 | Iowa City | IA | 4.0 ppb | 57/100 |
| 78 | 52242 | Iowa City | IA | 4.0 ppb | 67/100 |
| 79 | 52245 | Iowa City | IA | 4.0 ppb | 62/100 |
| 80 | 52246 | Iowa City | IA | 4.0 ppb | 63/100 |
| 81 | 52327 | Riverside | IA | 4.0 ppb | — |
| 82 | 52045 | Epworth | IA | 3.9 ppb | — |
| 83 | 52046 | Farley | IA | 3.9 ppb | — |
| 84 | 52053 | Holy Cross | IA | 3.9 ppb | — |
| 85 | 50428 | Clear Lake | IA | 3.6 ppb | — |
| 86 | 50482 | Ventura | IA | 3.6 ppb | — |
| 87 | 52057 | Manchester | IA | 3.6 ppb | — |
| 88 | 52742 | De Witt | IA | 3.4 ppb | 67/100 |
| 89 | 50112 | Grinnell | IA | 3.1 ppb | — |
| 90 | 52320 | Olin | IA | 3.1 ppb | — |
| 91 | 50036 | Boone | IA | 3.0 ppb | — |
| 92 | 50144 | Leon | IA | 3.0 ppb | — |
| 93 | 50212 | Ogden | IA | 3.0 ppb | — |
| 94 | 50223 | Pilot Mound | IA | 3.0 ppb | — |
| 95 | 50450 | Lake Mills | IA | 3.0 ppb | — |
| 96 | 50453 | Leland | IA | 3.0 ppb | — |
| 97 | 50473 | Scarville | IA | 3.0 ppb | — |
| 98 | 50625 | Dumont | IA | 3.0 ppb | — |
| 99 | 50627 | Eldora | IA | 3.0 ppb | — |
| 100 | 50672 | Steamboat Rock | IA | 3.0 ppb | — |
Methodology
Lead rankings are based on the 90th percentile lead testing value (PB90) reported by water systems under the Lead and Copper Rule. When CCR data is unavailable, EPA SDWIS lead sampling data is used. The EPA action level for lead is 15 ppb (0.015 mg/L). There is no safe level of lead exposure.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-10-14.
Frequently Asked Questions
What is a dangerous lead level in water?
The EPA action level is 15 parts per billion (ppb). The American Academy of Pediatrics recommends no more than 1 ppb for school drinking water. There is no safe level of lead exposure for children.
How is lead measured in water?
Water systems collect samples from homes with known lead service lines or lead solder. The 90th percentile value (PB90) means 90% of samples tested below that level. If PB90 exceeds 15 ppb, the system must take corrective action.
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