Lawrence, Massachusetts, was built on the Merrimack River. Literally. The city was founded in 1845 as a planned industrial city, centered on a dam and canal system designed to power textile mills. For over a century, those mills — and the river — defined the city.
Today, Lawrence is home to about 89,000 people and still draws its drinking water from the same Merrimack River that received industrial waste for generations. The river is cleaner than it was in the mid-20th century, but it carries new contamination challenges that residents should understand.
The Industrial River
The Merrimack River flows 117 miles from central New Hampshire to the Atlantic Ocean at Newburyport, Massachusetts. Along its path, it passes through mill cities including Concord and Manchester in New Hampshire, and Lowell, Lawrence, and Haverhill in Massachusetts.
For most of the 19th and 20th centuries, the Merrimack received direct discharges from:
- Textile mills — Dyes, bleaching agents, sizing chemicals, and fiber waste.
- Tanneries — Chromium compounds, sulfides, and organic waste.
- Paper mills — Chlorine compounds, dioxins, and organic solvents.
- Metal finishing operations — Heavy metals, acids, and solvents.
- Municipal sewage — Often untreated or minimally treated.
By the mid-20th century, the Merrimack was one of the most polluted rivers in the country. The Clean Water Act of 1972 began the slow process of recovery. Wastewater treatment plants were built, industrial discharges were regulated, and the river gradually improved.
But legacy contamination persists in sediments, and new contaminants — particularly PFAS — have emerged as significant concerns.
PFAS in the Merrimack
The Merrimack River has become one of the most prominent PFAS contamination stories in New England. Multiple sources contribute PFAS to the river:
- Saint-Gobain Performance Plastics in Merrimack, New Hampshire — This facility, which uses PTFE (Teflon-like) coatings, has been identified as a major source of PFAS air emissions that have contaminated groundwater and private wells in the area. While it’s an air deposition source, PFAS from contaminated groundwater eventually reaches the river.
- Wastewater treatment plants — Municipal treatment plants along the river receive PFAS from household products, industrial discharges, and landfill leachate. Conventional wastewater treatment doesn’t remove PFAS, so these facilities effectively pass PFAS through to the river.
- Military facilities — Pease Air Force Base (now Pease International Tradeport) in Portsmouth and other defense installations used AFFF firefighting foam containing PFAS.
New Hampshire set some of the strictest PFAS standards in the nation — 12 ppt for PFOA, 15 ppt for PFOS, 18 ppt for PFHxS, and 11 ppt for PFNA. Massachusetts has set a combined MCL of 20 ppt for six PFAS compounds. The federal standards finalized in 2024 set 4 ppt for PFOA and PFOS individually.
For Lawrence, which drinks from the Merrimack downstream of these sources, PFAS is not an abstract concern.
Current Drinking Water Quality
The City of Lawrence Water Treatment Plant draws water from the Merrimack River and treats it using a multi-step process including coagulation, flocculation, sedimentation, ozonation, biologically active filtration, and chloramination.
The plant has been upgraded over the years to handle the challenges of treating a river that flows through an industrialized watershed. Recent water quality highlights:
- PFAS — The city has been monitoring and reporting PFAS levels. Given the upstream sources, some PFAS compounds have been detected. Treatment upgrades — including granular activated carbon (GAC) — have been evaluated or implemented to address PFAS. Residents should check the latest Consumer Confidence Report for current levels.
- Disinfection byproducts — The use of ozone and chloramine (rather than free chlorine) helps reduce trihalomethane and haloacetic acid formation, keeping levels well within EPA limits.
- Lead and copper — Lawrence has significant lead service line exposure. The city’s housing stock is old — many homes date to the late 1800s and early 1900s. Lead service lines and lead plumbing are common. The city has been working on a lead service line inventory and replacement program.
- Turbidity — As a surface water system, turbidity varies with weather and seasonal conditions. The treatment plant manages this effectively, but heavy rain events can challenge the system.
Environmental Justice Considerations
Lawrence is one of the poorest cities in Massachusetts, with a median household income well below the state average. The city is predominantly Latino (over 80% Hispanic/Latino population) and has been identified as an environmental justice community under state law.
Environmental justice matters for water quality because:
- Lower-income residents are less likely to afford point-of-use filtration systems.
- Older, less expensive housing is more likely to have lead plumbing.
- Language barriers can limit access to water quality information published primarily in English.
- Community advocacy for infrastructure investment can be hampered by limited political capital.
Massachusetts’s environmental justice policies require enhanced public participation and analysis when environmental decisions affect communities like Lawrence. But policy requirements don’t automatically translate to cleaner water at the tap.
The Gas Explosions: Infrastructure Under Pressure
In September 2018, a series of gas explosions and fires struck Lawrence, Andover, and North Andover, caused by overpressurization of a natural gas delivery system. While primarily a gas infrastructure disaster, the event highlighted the broader infrastructure challenges facing Lawrence.
The city’s water infrastructure — pipes, mains, service connections — faces similar age-related vulnerabilities. Older water mains can be sources of contamination if they crack or leak, and old service connections are the primary pathway for lead exposure.
What Residents Can Do
- Test for lead at the tap. This is critical in Lawrence given the age of the housing stock. Contact the Lawrence Water Department or the Greater Lawrence Community Action Council for testing programs.
- Run cold water before drinking if the tap hasn’t been used for several hours. This flushes water that’s been sitting in contact with lead plumbing.
- Request PFAS data from the water department. As treatment upgrades proceed, residents should know what levels of PFAS are reaching their taps.
- Consider a certified water filter. Pitcher filters certified to NSF/ANSI 53 for lead reduction are the most affordable option. For broader protection including PFAS, reverse osmosis systems certified to NSF/ANSI 58 are more effective.
- Use cold water for cooking and baby formula. Hot water dissolves lead from plumbing more readily than cold water.
- Stay informed in your language. The Lawrence Water Department should provide water quality information in Spanish. If they don’t, request it.
The Bottom Line
Lawrence’s water treatment plant is modern and capable, but it’s fighting an uphill battle against a contaminated source river and an aging distribution system. PFAS from upstream sources is the newest challenge, added to a long list that includes legacy industrial contamination and lead service lines.
For a city where many residents can’t easily afford supplemental filtration, the quality of what comes out of the tap carries outsized importance. The treatment upgrades being pursued are essential, and residents should hold their water utility to the highest standard of transparency.
If you’re concerned about your water quality, a certified water treatment professional can test your water and advise on solutions tailored to your specific situation.
Sources: Massachusetts DEP PFAS regulations, EPA Lead and Copper Rule, Lawrence Water Department Consumer Confidence Reports, Merrimack River Watershed Council, New Hampshire DES PFAS investigation reports, Massachusetts Executive Office of Energy and Environmental Affairs environmental justice policy.