Community Water System · PWS WA5378398
Shoal Bay & Swift Bay Water Assn.
Operator location Lopez Island, Washington - smaller served population (≤ 999) at 35 people served; 69 SDWIS violations on record from groundwater sources.
- 35
- People served (this PWS)
- 69
- EPA violations (this PWS)
- 9
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Shoal Bay & Swift Bay Water Assn. standing, mid SDWIS violation third
35 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 13% is middle-third health share (≤ 23%).
The verdict
Shoal Bay & Swift Bay Water Assn. lands in the middle third by violation volume (69), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (35; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 13% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 69
- Total EPA violations on record
- 13%
- Health-based (MCL / treatment failure)
- 35
- 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
- 45
- County
- San Juan
- School/Daycare
- No
- MCL Violations
- 9
- Monitoring Violations
- 52
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 9 | 1997 |
| Chromium | MR | 4 | 2002 |
| CYANIDE | MR | 4 | 2002 |
| Mercury | MR | 4 | 2002 |
| Nickel | MR | 4 | 2002 |
| Selenium | MR | 4 | 2002 |
| Beryllium, Total | MR | 4 | 2002 |
| Antimony, Total | MR | 4 | 2002 |
| Arsenic | MR | 4 | 2002 |
| Barium | MR | 4 | 2002 |
| Fluoride | MR | 4 | 2002 |
| Cadmium | MR | 4 | 2002 |
| Thallium, Total | MR | 4 | 2002 |
| Consumer Confidence Rule | Other | 3 | 2017 |
| Coliform (TCR) | MR | 2 | 2010 |
| Lead and Copper Rule | MR | 1 | 1999 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1979 |
Violation Count vs. the National Corpus
Shoal Bay & Swift Bay Water Assn. has 69 recorded EPA violations, 65% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 35% carry more. 13% of this system's own violations are health-based (9 of 69), 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)
69 Around the middle fewer violations than 35% 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 Shoal Bay & Swift Bay Water Assn.
EPA SDWIS lists 35 people served and 45 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS · Washington State Department of Health, Office of Drinking Water
Nationwide peers
69 violations · 35 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
What to do with Shoal Bay & Swift Bay Water Assn.
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Washington compares on the same EPA violation measures. Washington 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.