Community Water System · PWS IA0640030
Keystone Water Supply
Operator location Keystone, Iowa - smaller served population (≤ 999) at 599 people served; 142 SDWIS violations on record from groundwater sources.
- 599
- People served (this PWS)
- 142
- EPA violations (this PWS)
- 25
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Keystone Water Supply standing, high SDWIS violation third
599 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 18% is middle-third health share (≤ 23%). Population rank #26,606 of 29,740 among systems serving 500+.
The verdict
Keystone Water Supply sits in the upper third of the sitemap cohort by violation count (142), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (599; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 18% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #26,606 of 29,740
- Population · /systems
- #501 of 545
- Population · IA
- 142
- Total EPA violations on record
- 18%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 280
- County
- Benton
- School/Daycare
- No
- MCL Violations
- 23
- Monitoring Violations
- 78
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrite | MR | 25 | 2015 |
| Nitrite | MCL | 23 | 2021 |
| Nitrate | MR | 20 | 2018 |
| Toluene | MR | 8 | 2013 |
| Coliform (TCR) | MR | 8 | 2013 |
| Lead and Copper Rule | MR | 4 | 2018 |
| Public Notice | Other | 4 | 2013 |
| Groundwater Rule | TT | 2 | 2021 |
| Barium | MR | 2 | 1988 |
| Chromium | MR | 2 | 1988 |
| Selenium | MR | 2 | 1988 |
| Cadmium | MR | 2 | 1988 |
| Arsenic | MR | 2 | 1988 |
| Fluoride | MR | 2 | 1988 |
| Mercury | MR | 1 | 1988 |
Violation Count vs. the National Corpus
Keystone Water Supply has 142 recorded EPA violations, 80% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 20% carry more. 18% of this system's own violations are health-based (25 of 142), and it ranks #26,606 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
142 Higher than most more violations than 80% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Population served record for Keystone Water Supply
EPA SDWIS lists 599 people served and 280 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
142 violations · 599 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with smaller service footprints
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Keystone Water Supply
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Iowa compares on the same EPA violation measures. Iowa systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.