Thompson, CT · PWSID CT1410011
CTWC - Thompson System lead service lines
20 lead or galvanized lines to replace
CTWC - Thompson System reported 0 lead and 20 galvanized-requiring-replacement service lines out of 486 in its inventory. That's about 1 in 24 lines. Another 314 (65%) are still listed as unknown material.
Ranks #38 of 71 Connecticut systems with confirmed lead lines, and #3,730 nationally.
4.1% of CTWC - Thompson System's service lines are lead or galvanized requiring replacement. That's higher than the Connecticut average (1.6%) and higher than the national average (3.1%).
- Lead 0%
- Galvanized (replace) 4.1%
- Unknown 65%
- Non-lead 31%
Total service lines reported: 486. Reported all required service line types. Population served: 1,070; 484 connections.
Lead test results
CTWC - Thompson System's most recent 90th-percentile lead result (2025) was 1.1 ppb, below both the 15 ppb action level and the 10 ppb level that takes effect in 2027. This means 90% of homes sampled were at or below that level; individual homes, especially those with lead lines, can be higher.
Lead and Copper Rule 90th-percentile results reported to EPA, in parts per billion. Dashed lines: 15 ppb action level and the 10 ppb level from November 1, 2027.
Progress since 2025 Q1
Reported lead and galvanized-requiring-replacement lines went from 20 in 2025 Q1 to 20 in 2026 Q3: no change. Lines of unknown material went from 314 to 314, no change.
Quarterly counts reported to EPA. A drop usually means lines were replaced or confirmed non-lead; a rise usually means more lines were identified. Replacement progress rankings.
Lead rule violations
EPA's data lists no Lead and Copper Rule violations for CTWC - Thompson System since 2015. That covers testing, reporting, corrosion control and public notice requirements; it isn't a guarantee about any individual home.
Source: EPA SDWIS violation records for the Lead and Copper Rule.
Where the water comes from
CTWC - Thompson System's main water source is groundwater (wells).
Source: EPA SDWIS water system and facility records.
Check your own address
These counts cover the whole system. To see whether your line is lead, use the utility's address-level inventory. Utilities had to prepare one by October 16, 2024 and make it publicly accessible; systems serving more than 50,000 people must post it online.
No map yet? Do the 2-minute scratch and magnet test on the pipe where water enters your home.
Protect your drinking water now
If your line is lead, galvanized or unknown, filter water for drinking, cooking and baby formula. Use a filter certified to NSF/ANSI 53 for lead. Run cold water for a few minutes after it sits for hours, and never use hot tap water for cooking.
How to pick a lead-certified filter · How to test your water for lead
Getting the line replaced
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask CTWC - Thompson System whether it replaces the private side for free or with a cost share before you hire anyone. If you want it done sooner, or your utility doesn't cover your side, a licensed plumber can quote it. What replacement costs.
County pages: Lead pipes in Windham County
Other water systems nearby
| System | Lead + galv. | Unknown |
|---|---|---|
| Windham Water Works | 352 | 5 |
| Putnam Water Pollution Control Authority | 176 | 90 |
| CTWC - Crystal System | 93 | 929 |
| CTWC - Gallup System | 24 | 700 |
| CTWC - Plainfield System | 1 | 419 |
| CTWC - Ashford Park Division | 0 | 106 |
| Sterling Water System | 0 | 23 |
| CTWC - Pompey Hollow Division | 0 | 5 |
Check another water system
Questions
Does CTWC - Thompson System have lead pipes?
Yes. CTWC - Thompson System reported 0 lead service lines and 20 galvanized lines that must be replaced, out of 486 total. 314 more are of unknown material.
How do I check if my home's service line is lead?
Look up your address on CTWC - Thompson System's official service line inventory, which utilities must make publicly available. You can also scratch the pipe where it enters your home: lead is soft, dull gray, scratches to shiny silver and does not attract a magnet.
When will CTWC - Thompson System replace lead service lines?
Under EPA's Lead and Copper Rule Improvements, most systems must replace lead and galvanized-requiring-replacement lines by December 31, 2037, starting from November 1, 2027. The rule is being challenged in court, so dates could change. Many utilities run free or cost-share programs now.
Has CTWC - Thompson System had lead violations?
EPA's data shows no Lead and Copper Rule violations since 2015 for CTWC - Thompson System.
Which water filters remove lead?
Use a filter certified to NSF/ANSI Standard 53 for lead reduction, or NSF/ANSI 58 for reverse osmosis. Check the certification on NSF's listings, not just the box.
Embed or cite this data
Local news sites, blogs and community groups can embed this card. It updates when EPA releases new data.
Citation: Lead Pipe Map, "CTWC - Thompson System lead service lines," https://leadpipemap.com/ct/ctwc-thompson-system/. Source: EPA SDWIS service line inventory, 2026 Q3. Download the full dataset on the data page.