Community Water System · PWS OR4100174
Knoll Terrace Park
Operator location Corvallis, Oregon - smaller served population (≤ 999) at 452 people served; 94 SDWIS violations on record from groundwater sources.
- 452
- People served (this PWS)
- 94
- EPA violations (this PWS)
- 1
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Knoll Terrace Park standing, high SDWIS violation third
452 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 1% is middle-third health share (≤ 23%).
The verdict
Knoll Terrace Park sits in the upper third of the sitemap cohort by violation count (94), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (452; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 1% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 94
- Total EPA violations on record
- 1%
- Health-based (MCL / treatment failure)
- 452
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 210
- County
- Benton
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 63
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Consumer Confidence Rule | Other | 8 | 2025 |
| COLIPHAGE | MR | 4 | 2012 |
| Gross Alpha, Excl. Radon and U | MR | 2 | 1996 |
| 1,2,4-Trichlorobenzene | MR | 1 | 2002 |
| Xylenes, Total | MR | 1 | 2002 |
| p-Dichlorobenzene | MR | 1 | 2002 |
| trans-1,2-Dichloroethylene | MR | 1 | 2002 |
| 1,2-Dichloroethane | MR | 1 | 2002 |
| 1,2-Dichloropropane | MR | 1 | 2002 |
| Trichloroethylene | MR | 1 | 2002 |
| 1,1,2-Trichloroethane | MR | 1 | 2002 |
| Tetrachloroethylene | MR | 1 | 2002 |
| Benzene | MR | 1 | 2002 |
| Toluene | MR | 1 | 2002 |
| Styrene | MR | 1 | 2002 |
| Methoxychlor | MR | 1 | 2002 |
| Toxaphene | MR | 1 | 2002 |
| Dalapon | MR | 1 | 2002 |
| Glyphosate | MR | 1 | 2002 |
| Di(2-ethylhexyl) adipate | MR | 1 | 2002 |
| OXAMYL | MR | 1 | 2002 |
| Simazine | MR | 1 | 2002 |
| Picloram | MR | 1 | 2002 |
| Hexachlorocyclopentadiene | MR | 1 | 2002 |
| Benzo(a)pyrene | MR | 1 | 2002 |
| Pentachlorophenol | MR | 1 | 2002 |
| Total Polychlorinated Biphenyls (PCB) | MR | 1 | 2002 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 1 | 2002 |
| ETHYLENE DIBROMIDE | MR | 1 | 2002 |
| Chlordane | MR | 1 | 2002 |
Violation Count vs. the National Corpus
Knoll Terrace Park has 94 recorded EPA violations, 72% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 28% carry more. 1% of this system's own violations are health-based (1 of 94), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
94 Around the middle fewer violations than 28% 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 Knoll Terrace Park
EPA SDWIS lists 452 people served and 210 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
94 violations · 452 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.
What to do with Knoll Terrace Park
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Oregon compares on the same EPA violation measures. Oregon 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.