Here is what the EPA's own data shows about tap water in Nashua. According to EPA SDWIS data retrieved October 2026, Nashua is served by 73 active community water systems, together reported to serve about 131,406 people.
As of October 2026, EPA records show 102 violations across the community water system(s) serving Nashua, going back to the earliest EPA record. 25 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2008. All have since returned to compliance, per EPA records.
Litchfield
6,920 served · surface water · PWSID NH1371010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Londonderry
6,255 served · surface water · PWSID NH1391010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Penacook Boscawen Water Pct
3,800 served · groundwater · PWSID NH0251010
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2017. All have since returned to compliance, per EPA records.
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2017. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2009. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2009. All have since returned to compliance, per EPA records.
Little Pond Estates
3,000 served · surface water · PWSID NH0192080
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Locke Lake
2,308 served · surface water · PWSID NH0142010
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between January 2018 and April 2018. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in August 2012. All have since returned to compliance, per EPA records.
Pittsfield Aqueduct
1,625 served · surface water · PWSID NH1911010
Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2019. All have since returned to compliance, per EPA records.
Monitoring Long Term 2 Enhanced Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2019. EPA records do not show all of these as returned to compliance.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2010. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2010. All have since returned to compliance, per EPA records.
Belmont Water Dept
1,612 served · groundwater · PWSID NH0201010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Drew Woods
1,413 served · surface water · PWSID NH0612150
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2009. All have since returned to compliance, per EPA records.
Powder Hill
1,148 served · surface water · PWSID NH0192050
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Cabot Preserve
965 served · groundwater · PWSID NH0192070
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2007. All have since returned to compliance, per EPA records.
Williamsburg
910 served · groundwater · PWSID NH1851010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Brook Park Ests
880 served · surface water · PWSID NH1392060
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2006. All have since returned to compliance, per EPA records.
Green Hills Ests
618 served · groundwater · PWSID NH1973030
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Birch Hill East
560 served · groundwater · PWSID NH0512010
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2004. All have since returned to compliance, per EPA records.
W And E
528 served · groundwater · PWSID NH2542030
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. All have since returned to compliance, per EPA records.
Maple Hill Acres
500 served · surface water · PWSID NH0612020
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Whispering Winds
488 served · surface water · PWSID NH1851020
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2008. All have since returned to compliance, per EPA records.
Badger Hill
455 served · groundwater · PWSID NH1562030
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Avery Estates
383 served · surface water · PWSID NH1392250
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Twin Ridge Condos
348 served · surface water · PWSID NH1932050
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Golden Brook
328 served · groundwater · PWSID NH2542010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Oakwood Terrace
310 served · surface water · PWSID NH0612010
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Ministerial/Parrish Hills
305 served · groundwater · PWSID NH1392310
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Villages At Stow
300 served · groundwater · PWSID MA2286024
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Souhegan Woods
298 served · groundwater · PWSID NH0072070
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Glen Ridge Dev
263 served · groundwater · PWSID NH0612070
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Maple Haven
258 served · groundwater · PWSID NH0612170
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Sunrise Estates
235 served · groundwater · PWSID NH1542030
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2003. All have since returned to compliance, per EPA records.
Springwood Hills
228 served · surface water · PWSID NH1392260
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Great Bay Water System
228 served · groundwater · PWSID NH1732030
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Hudson Mobile Home Ests
220 served · groundwater · PWSID NH1203010
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between July 2015 and October 2015. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2017. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between June 2006 and January 2011. All have since returned to compliance, per EPA records.
Wesco Utilities
210 served · groundwater · PWSID NH1182050
Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 1994. The EPA record lists a level of 0 ; the limit (MCL) is 0 . All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2010. All have since returned to compliance, per EPA records.
Woodlands
203 served · groundwater · PWSID NH0762120
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Valley Field Apts Northland
200 served · groundwater · PWSID NH1932070
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Autumn Woods
193 served · groundwater · PWSID NH2052070
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2003. All have since returned to compliance, per EPA records.
Liberty Tree Acres
190 served · groundwater · PWSID NH1972010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Harvest Village
185 served · groundwater · PWSID NH1392290
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Mountainside At Crotched Mtn
180 served · groundwater · PWSID NH0212020
Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in March 2013. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between July 2008 and July 2014. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 2008 and February 2014. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2004 and October 2010. All have since returned to compliance, per EPA records.
Clearwater Estates
173 served · groundwater · PWSID NH1972070
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Lamplighter Village
173 served · groundwater · PWSID NH2542170
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Smythe Woods
168 served · surface water · PWSID NH1182040
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Sky View Estates
168 served · groundwater · PWSID NH1852120
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2015. All have since returned to compliance, per EPA records.
Belmont Water Dept/North
150 served · surface water · PWSID NH0201020
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2012. All have since returned to compliance, per EPA records.
Hi And Lo Estates
150 served · surface water · PWSID NH0612140
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2018. All have since returned to compliance, per EPA records.
Forest Ridge
140 served · groundwater · PWSID NH0802040
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in August 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Fletcher Corner Estates
140 served · groundwater · PWSID NH2542150
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Meadowbrook Acres Mobile Home Park
137 served · groundwater · PWSID MA1043001
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Winnisquam Village Condos
133 served · groundwater · PWSID NH2352040
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Spruce Pond Ests
133 served · groundwater · PWSID NH2542180
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
White Rock Senior Living
120 served · groundwater · PWSID NH0262050
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2003. All have since returned to compliance, per EPA records.
Hardwood Hts Birch Hill
120 served · groundwater · PWSID NH2542060
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Stone Sled Farm
113 served · groundwater · PWSID NH0262060
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Wood Meadow Estates
113 served · groundwater · PWSID NH2542200
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2019. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2020. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2019. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2019. All have since returned to compliance, per EPA records.
Castle Reach
110 served · groundwater · PWSID NH2542140
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in September 2021. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2018. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Pinehaven Water Trust
95 served · groundwater · PWSID NH1392040
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Farmstead Acres
93 served · groundwater · PWSID NH0612110
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Northern Shores
93 served · groundwater · PWSID NH2352020
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between April 2002 and September 2003. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2003. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2003. All have since returned to compliance, per EPA records.
Thurston Woods
90 served · groundwater · PWSID NH1332050
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Shaker Heights
88 served · groundwater · PWSID NH0432040
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Farley Rd Estates
85 served · groundwater · PWSID NH1622010
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Sweet Hill Estates
85 served · surface water · PWSID NH1932200
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2018. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Daniels Lake
78 served · groundwater · PWSID NH2452010
Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2007. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Ashley Commons
75 served · groundwater · PWSID NH1562020
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Gage Hill
73 served · groundwater · PWSID NH1852020
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Cross Ridge Estates
73 served · groundwater · PWSID NH1932120
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2006 and July 2011. All have since returned to compliance, per EPA records.
Hillcrest Manor Apts
65 served · groundwater · PWSID NH0362010
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2020. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2016 and October 2017. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between October 2004 and July 2012. All have since returned to compliance, per EPA records.
English Woods
58 served · groundwater · PWSID NH0192060
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
The Dox Condos
55 served · groundwater · PWSID NH2087010
Health-based Combined Uranium: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between July 2023 and July 2024. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2012. All have since returned to compliance, per EPA records.
Castleton Meadows
50 served · groundwater · PWSID VT0005515
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Briarwood Townhomes
40 served · groundwater · PWSID MA2140013
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Hollis Village Marketplace
36 served · groundwater · PWSID NH1176010
Health-based Antimony, Total: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between July 2023 and January 2024. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between October 2014 and April 2023. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between September 2016 and January 2020. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between November 2014 and August 2023. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between September 2016 and January 2020. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2012 and April 2015. All have since returned to compliance, per EPA records.
Beaver Hollow
30 served · groundwater · PWSID NH2082010
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.