Guest Column | January 25, 2022

New Hampshire Puts $350 Million To Work From A Successful Lawsuit Over MTBE Contamination

By Ashley Campbell


From cleaner water to infrastructure upgrades, good stories are easy to find after the state of New Hampshire set out to hold polluters accountable for contaminating groundwater with methyl tertiary-butyl ether (MTBE), a gasoline additive now banned or limited in several states. Through private well testing, watershed protection and new water facilities, the people of the Granite State are turning the tide on water contamination and restoring the safety and reliability of their drinking water supplies thanks to bold action to make sure polluters pay for damage.

In all, the state’s legal strategy has delivered more than $350 million in funds to improve water infrastructure and clean up groundwater contamination. Of that total, more than $275 million has come from New Hampshire’s landmark verdict from its case against ExxonMobil and another $81 million from settlements with other refiners and suppliers. Over the years, the two funds together have been used to conserve undeveloped land and shoreline, upgrade centuries-old water infrastructure, test hundreds of private wells for contaminants — including MTBE, per- and polyfluoroalkyl substances (PFAS), and volatile organic compounds — and build water treatment facilities.

A Landmark Case Against Polluters

The original lawsuit brought by the state of New Hampshire goes back to 2003, when the state sued several gasoline suppliers, refiners and chemical manufacturers seeking damages for groundwater contamination from MTBE. All defendants except ExxonMobil settled with the state but ExxonMobil was held liable after a three-month trial. Made from methanol, MTBE was originally added to unleaded gasoline back in the 1980s to make it burn cleaner. Its use was widespread in the 1990s. Because it was made using a byproduct of the gasoline refining process, it was inexpensive to make.

But over time, people found out that MTBE was contaminating groundwater, often through leaking underground gasoline storage tanks. The chemical spreads quickly — and over great distances — through the soil and groundwater, and even in small amounts it poses a risk to human health. A small amount can pollute a large amount of groundwater. MTBE today has been largely replaced by other additives such as ethanol.

The state’s former Attorney General Joe Foster has remarked to news media that this was the state’s most significant environmental victory. SL Environmental attorneys worked on this groundbreaking lawsuit against 22 major oil companies for contaminating water with MTBE. Their deep experience in environmental litigation helps municipalities, water purveyors, and others interested in ensuring polluters pay to clean up the contamination they left behind.

Spending The Funds To Improve Water Supplies

Today, states and communities are looking at how New Hampshire is using the funds from its settlements and verdict to make community drinking water system improvements and address the statewide problem of MTBE contamination. This work is done through the state’s MTBE Remediation Bureau, established by the New Hampshire Department of Environmental Services in 2014.

In general, the funds fall into two separate pots of money with distinct rules. One pot of money came from the settlement agreements with refineries and suppliers. These MTBE settlement funds can only be used to address MTBE contamination in New Hampshire. This can mean anything from finding and cleaning up existing MTBE contamination to providing safe, clean drinking water to impacted residents, and preventing future contamination.

The other pot of money holds funds from the jury verdict won in the ExxonMobil case which went to trial. These funds were placed in New Hampshire’s Drinking Water and Groundwater Trust Fund (DWGTF), which in 2017 was purpose-built for this function. The same law that created the fund also established an advisory commission dedicated to developing a comprehensive strategy to ensure safe drinking water for all residents. That commission develops and leads the process for providing both grants and low-interest loans to municipalities and water systems for protection, preservation, and improve the state’s drinking water and groundwater resources. The MTBE Remediation Bureau administers the trust fund.

Cleaning Up MTBE

According to the most recent annual report published by the state, there are at least 550 MTBE-contaminated sites in New Hampshire and possibly many more. A 2008 study by the U.S. Geological Survey found MTBE present at detectable levels in approximately 10 percent of southeast New Hampshire wells, confirming that the chemical continues to be a statewide issue. The report notes that the state estimates that 10 percent of all private drinking water wells in New Hampshire are contaminated with MTBE.

Nearly all of the settlement funds spent since program inception have funded clean-up work, water supply testing, water supply infrastructure improvement or replacement projects, and MTBE Remediation Bureau labor costs associated with project management.

As of the end of FY19, the state has completed remedial projects in 43 municipalities throughout the state. These projects typically involved the removal of underground gasoline storage tanks and contaminated soil that was inaccessible prior to tank system removal. Approximately 20,200 tons of contaminated soil have been removed and properly disposed. The State has tested more than 7,000 water quality samples and acted to identify and remove underground storage tanks that may leak MTBE via old gasoline.

Other Water Quality Improvements

Acknowledging that ensuring safe and clean water supplies for its residents stretches beyond addressing the MTBE contamination problem, especially as emerging contaminations such as PFAS gain more attention and concern, the DWGTF has provided about $124 million to over 90 projects benefiting many of its residents since its creation in 2017. The highest priority for funding goes to projects addressing drinking water contamination, according to its website. Funds are also directed toward projects that improve drinking water infrastructure or protect water sources.

The first community to receive money from the DWGTF for infrastructure upgrades was the town of Colebrook. It received $1.15 million to replace aging, leaky water mains and the service lines that connect them to users. They also spent money on new, “smart” meters that let customers track water use in real time. The upgrades freed up local money for sewer upgrades. Dozens of similar projects have been funded throughout the state, from Stewartstown in the north to Nashua in the south and all points in between. (See the map of infrastructure and source water protection projects.)

Another DWGTF grant went to the Forest Society and Manchester Water Works to conserve the majority of the last available undeveloped land and shoreline on Lake Massabesic. The lake provides drinking water to 160,000 residents of Manchester and nearby towns and will be protected as open space for generations to come. The Forest Society also used DWGTF grant funds to purchase and protect land in the Stillhouse Forest and make it available to the public for hiking and other recreation. According to DWGTF records, more than 5,000 acres of land have been protected with its funds from 2017 to 2020. These land purchases are all part of a broad vision that prioritizes the protection, preservation and enhancement of the drinking water and groundwater resources of New Hampshire.


Cleaning MTBE contamination out of New Hampshire’s water supplies will take time, and there remains much more work to do. As this continues, it is important to acknowledge and applaud the progress and investments made possible by a state that boldly turned to the courts to hold companies responsible for environmental harms related to their products. It’s a model that many states, municipalities, and water agencies can emulate to make polluters pay for harm done to their communities.

Ashley Campbell, Attorney at SL Environmental Law Group, exclusively represents drinking water suppliers, including cities, water districts, mutual water companies, and other utilities in identifying and holding groundwater polluters accountable. She can be reached at