Manchester – New Hampshire – Water Quality Report 2025: PFAS Testing, Infrastructure Concerns & Safety across your city
Manchester Water Works provides essential water services to approximately 180,000 residents across Manchester, New Hampshire and portions of Auburn, Bedford, Derry, Goffstown, Hooksett, and Londonderry. Established in 1874, the system maintains over 500 miles of water distribution lines, multiple treatment facilities, and advanced infrastructure that delivers an average of 17 million gallons of drinking water daily to New Hampshire’s largest city and surrounding communities.
Manchester sources its drinking water primarily from Lake Massabesic, a 2,560-acre reservoir covering parts of Manchester and Auburn that has served as the region’s water supply for over 150 years. The lake water is treated at Manchester’s Water Treatment Plant, completed in 1974 and significantly upgraded in 2006, with a maximum capacity of 50 million gallons per day. In 2023, Manchester added a new water source with the completion of the $40 million Merrimack River Treatment Facility, featuring advanced radial collector well technology and providing up to 7.2 million gallons per day of additional capacity. Manchester’s water consistently meets all federal and state quality standards, though the utility faces ongoing challenges with infrastructure modernization, emerging contaminants like PFAS, and meeting growing regional demand.
Manchester Water Quality: Current Status (2024-2025)
Latest Testing Results
- Federal Compliance: For the most recent quarter assessed by the U.S. EPA (April 2024 – June 2024), Manchester Water Works was in full compliance with all federal health-based drinking water standards.
- Testing Scope: Manchester conducts comprehensive water quality monitoring throughout the system, including routine testing at treatment facilities and throughout the 500+ mile distribution network.
- Compliance Status: Manchester’s water consistently meets all federal and state drinking water standards, maintaining compliance with EPA and New Hampshire Department of Environmental Services regulations.
Water Sources
- Lake Massabesic: Primary source since 1874, covering 2,560 acres in Manchester and Auburn with a name meaning “place of much water” in Native American language, providing safe yield capacity of 20.2 million gallons per day.
- Merrimack River Source: New radial collector well system completed in 2023, using innovative riverbank filtration technology to provide up to 7.2 million gallons per day of additional supply.
- Watershed Protection: Comprehensive protection of Lake Massabesic watershed with restrictions on swimming and water skiing to maintain water quality for drinking water purposes.
Advanced Treatment Technology
- Lake Massabesic Treatment Plant: Main facility completed in 1974 and significantly upgraded in 2006, utilizing multi-barrier treatment including coagulation, flocculation, sedimentation, filtration, and disinfection with a maximum capacity of 50 million gallons per day.
- Merrimack River Treatment Facility: State-of-the-art facility opened in 2023 featuring granular activated carbon and ultraviolet light treatment for advanced water purification and disinfection.
- Disinfection Management: Annual temporary switch from chloramine to free chlorine disinfection (typically August through October) to maintain system cleanliness and prevent biofilm formation in distribution lines.
Infrastructure Modernization
- Regional Water Project: Manchester serves as the hub for the Southern New Hampshire Regional Water Project, providing 3.13 million gallons per day to six additional towns including Salem, Windham, Hampstead, and Plaistow.
- Distribution System Improvements: Ongoing modernization of the 500+ mile distribution network, including water main replacements and smart monitoring systems to improve reliability and reduce water loss.
- Emergency Preparedness: Dual-source capability provides enhanced system resilience and security of supply during maintenance, emergencies, or seasonal demand fluctuations.
Customer Protection Initiatives
Manchester Water Works provides comprehensive customer support through various programs, including the Service Line Protection Plan that covers water service lines from the property line into homes. The utility maintains transparent communication through annual water quality reports and proactive public notifications about system changes such as disinfection conversions. Manchester’s significant investments in treatment technology upgrades and the new Merrimack River facility demonstrate the utility’s commitment to providing safe, reliable drinking water while addressing future challenges including population growth, emerging contaminants, and the need to serve additional regional communities. The utility’s 24/7 customer service ensures rapid response to emergencies and water quality concerns.
Recommendations for Manchester Residents
Monitor Water Quality
Stay informed about Manchester’s water quality through annual water quality reports available at manchesternh.gov. Contact Manchester Water Works at 603-624-6494 for any water quality concerns or to request testing information.
Conserve Water
Help protect Lake Massabesic and the Merrimack River sources by practicing water conservation. Report leaks promptly to Manchester Water Works and consider drought-resistant landscaping during peak summer demand periods.
Consider Home Filtration
While Manchester’s water meets all standards, residents concerned about emerging contaminants like PFAS or disinfection byproducts may benefit from NSF-certified home filtration systems for drinking and cooking water.
Protect Service Lines
Consider enrolling in Manchester Water Works’ Service Line Protection Plan, which covers the water service line from your property line into your home. This optional program helps protect against unexpected repair costs.
Report Issues
Contact Manchester Water Works Customer Service at 603-624-6494 (available 24/7) for water emergencies, pressure problems, or quality concerns. Report any water main breaks or leaks immediately to help maintain system integrity.
Frequently Asked Questions
Is Manchester’s tap water safe to drink?
Yes, Manchester’s tap water meets all federal and state drinking water standards. The water comes from two sources: Lake Massabesic (primary) and the Merrimack River (secondary), both of which undergo comprehensive multi-barrier treatment.
Manchester Water Works conducts extensive testing to ensure water quality throughout the system. The Lake Massabesic treatment plant has been serving the region since 1974 with continuous upgrades, while the new Merrimack River facility incorporates cutting-edge treatment technology. The utility’s commitment to safety is demonstrated through transparent reporting and proactive communication about any system changes.
Why does my water taste different in summer?
Taste changes in summer can occur due to several factors:
1. Annual disinfection switch: Each summer (typically August through October), Manchester Water Works temporarily switches from chloramine to free chlorine disinfection, which may cause a more noticeable chlorine smell
2. Increased demand: Summer water consumption can double to 20 million gallons per day, which may affect Lake Massabesic water levels and characteristics
3. Seasonal water quality changes: Natural variations in source water temperature and conditions can affect taste
If taste or odor issues persist beyond the normal disinfection period, contact Manchester Water Works at 603-624-6494 for assistance.
What about PFAS in Manchester’s water?
PFAS (per- and polyfluoroalkyl substances) have been detected at low levels in Manchester’s water sources, consistent with widespread environmental contamination throughout New Hampshire:
• Monitoring: Manchester Water Works monitors PFAS levels in accordance with state and federal regulations, with the EPA finalizing new PFAS regulations in 2024
• Treatment capability: The new Merrimack River Treatment Facility includes granular activated carbon treatment, which is effective at removing PFAS compounds
• Regional issue: PFAS contamination affects many New Hampshire communities due to historical use of firefighting foams and industrial processes
• Health guidelines: Current levels are being evaluated against evolving health guidelines as research continues
Manchester is actively working to address emerging contaminants while maintaining compliance with all current regulations.
How does the new Merrimack River source work?
Manchester’s new water source uses innovative radial collector well technology:
Radial Collector Well:
• First of its kind in New Hampshire, featuring horizontal wells extending into the riverbed
• Uses natural riverbank filtration as the first treatment barrier
• Provides up to 7.2 million gallons per day of additional capacity
Treatment Process:
• Raw water travels through a 20-inch pipeline to the new treatment facility
• Advanced treatment includes granular activated carbon and ultraviolet disinfection
• Meets or exceeds the quality standards of the Lake Massabesic plant
This dual-source approach provides enhanced reliability and helps Manchester serve additional communities through the Southern New Hampshire Regional Water Project.
Contaminants of Concern
PFAS Compounds
Source: Per- and polyfluoroalkyl substances from historical use of firefighting foams and industrial processes that have contaminated groundwater and surface water sources throughout New Hampshire
Health Effects: Research indicates potential health concerns including impacts on immune system, thyroid function, cholesterol levels, and possible links to certain cancers
Current Status: Detected at low levels in source waters; Manchester is monitoring regulatory developments and has incorporated PFAS-removal technology in the new Merrimack River facility EPA Limits: New EPA regulations for specific PFAS compounds were finalized in 2024
Disinfection Byproducts
Source: Formed when disinfectants such as chlorine or chloramine react with naturally occurring organic matter in Lake Massabesic and Merrimack River source waters
Health Effects: Long-term exposure to elevated levels may increase risk of certain cancers and potentially affect liver, kidney, and central nervous system
Current Levels: Monitored regularly throughout the distribution system with levels maintained below EPA maximum contaminant levels EPA Limits: 80 ppb for total trihalomethanes (TTHMs) and 60 ppb for haloacetic acids (HAA5)
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