Non-Transient Non-Community Water System · PWS MA2179011
Southwicks Zoo
Operator location Mendon, Massachusetts - 9% of 22 violations are health-based (middle-third health share (≤ 23%)); groundwater source; 1,000 served per SDWIS.
- 1,000
- People served (this PWS)
- 22
- EPA violations (this PWS)
- 2
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Southwicks Zoo standing, mid SDWIS violation third
9% of 22 recorded violations are health-based - middle-third health share (≤ 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 9% is middle-third health share (≤ 23%). Population rank #19,583 of 29,740 among systems serving 500+.
The verdict
Southwicks Zoo lands in the middle third by violation volume (22), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is mid-pack at 1,000 (mid served population (≤ 3,309)). Health-based share is 9% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #19,583 of 29,740
- Population · /systems
- #330 of 418
- Population · MA
- 22
- Total EPA violations on record
- 9%
- 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
- Non-Transient Non-Community
- Owner Type
- Private
- Connections
- 1
- County
- Worcester
- School/Daycare
- No
- MCL Violations
- 2
- Monitoring Violations
- 15
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 13 | 2014 |
| Revised Total Coliform Rule | RPT | 2 | 2018 |
| Nitrate | MR | 2 | 1998 |
| Coliform (TCR) | MCL | 2 | 1999 |
Violation Count vs. the National Corpus
Southwicks Zoo has 22 recorded EPA violations, 34% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 65% carry more. 9% of this system's own violations are health-based (2 of 22), and it ranks #19,583 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)
22 Lower than most fewer violations than 65% 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
Health-based violations on Southwicks Zoo
2 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for MA2179011.
Sources: EPA SDWIS · MassDEP, Drinking Water Program
Nationwide peers
22 violations · 1,000 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.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Southwicks Zoo
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Massachusetts compares on the same EPA violation measures. Massachusetts 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.