MassDEP Emergency Responders, FAST Vehicle Key to Cleanup of Massive Gasoline Spill in Newburyport

On July 6, 2009, the Massachusetts Department of Environmental Protection (MassDEP) joined local, state and federal emergency response personnel and equipment at a mid-morning rollover accident involving a fully-loaded gasoline tanker on Interstate 95 North in Newburyport.

A leaking overturned 10,000 gallon gasoline tanker lies on its side on Route 95 in Newburyport as MassDEP's emergency response and FAST (Field Assessment & Support Team) arrive to assist in cleanup.

MassDEP's emergency response unit, along with the agency's FAST vehicle (Field Assessment & Support Team), arrived to find the tanker, which lay on its side just south of the Ferry Road overpass, leaking its 10,200 gallons of gasoline onto the roadway. 

Gasoline was running off the highway, into catch basins and storm drains with a visible sheen of gasoline emerging from a stormwater outfall pipe on the nearby Merrimack River (See Figure 1).

Aerial map of gasoline spill impact in Newburyport on Route 95 near the Merrimack River following a tanker accident on July 6, 2009.
 

MassDEP determined that approximately 8,200 gallons of gasoline had impacted the environment. Another 400 gallons of gasoline was recovered by vacuum trucks from the highway area, the catch basins and the surface of the river, while approximately 1,600 gallons of fuel was off-loaded from the tanker during recovery operations.


Containment boom put in place as a visible sheen of gasoline emerges on the Merrimack River after gasoline made its way from the leaking tanker to the road into nearby storm drains and out to the river.

Public water supply officials in Newburyport, which has two wells nearby (Figure 1) were immediately notified and as a precaution those wells were taken off line.  The water supplier had adequate supply already in storage sufficient to continue to provide its customers. 

A potentially significant amount of gasoline had leached into the ground, so MassDEP determined that contaminated soil would need to be removed to prevent groundwater contamination and possible impacts on nearby water supplies. The installation of monitoring wells was undertaken to determine where spreading contamination existed below ground.

As of July 15, testing of water supply wells has consistently shown no evidence of any contamination from the spill having impacted these wells, but both fields would remain off line as a precaution.

The spill site is located approximately 150 feet west of a residential development that includes Laurel Road (Figure 1), which runs parallel to Route 95.  Homes in this area were evacuated shortly after the accident, and power to Laurel Road was cut off.

A decision was made at the scene by MassDEP that FAST vehicle resources were best utilized by monitoring potential impacts to the Laurel Road neighborhood.  Four air monitoring units were deployed at strategic points by FAST personnel based on wind speed and direction.  

While a significant gasoline odor was present in the spill area on the highway, the residential neighborhood remained largely free of odors.

Several ambient air samples were also taken in the neighborhood for analysis on the FAST vehicle's on-board diagnostic equipment. The results of these analyses indicated essentially minimal concentrations of gasoline contaminants.

While one home on Laurel Road was found to have a discernable odor of gasoline in the basement, a decision was made jointly by the response team and utility crews that power could be restored later that day to the rest of the neighborhood.

The air in this one home had a discernable odor of gasoline as analyzed on board the FAST vehicle. The basement of the home was ventilated for several hours, the odors diminished and another sample was analyzed. This time, levels had returned to normal.

However, in order to evaluate whether contamination below ground might pose a long-term threat, a soil-gas probe was installed. A sample was obtained and analyzed, revealing low but discernible levels of gasoline vapors.  Because of the uncertainty of a possible vapor intrusion pathway, the resident elected to spend the night elsewhere, and power was not restored to this structure.

By the end of the first day, MassDEP and the U.S. Environmental Protection Agency (EPA) issued a joint press release updating the public on the response.

As the cleanup continued into the second day, WBZ-TV Channel 4 came by to interview MassDEP crew members aboard the FAST vehicle.  Follow the link to catch that clip:
http://wbztv.com/video/?id=78652@wbz.dayport.com.

MassDEP's Field Assesment and Support Team (FAST) Vehicle

• close to 600 yards of soil had been removed, with more expected;
• a total of 12 catch basins had been cleaned out, with approximately five drums of debris/material collected from each basin;
• water around the outfall on the Merrimack River continued to show improvement with the need to replace containment boom surrounding the spill becoming less frequent;
• air quality testing consistently coming back clean, but with a residual gasoline odor noticeable on occasion, due to soil removal activities, but not presenting a health problem;
• additional assessment below surface continues and will continue with three monitoring wells so far having been installed (another 10 or 12 monitoring wells will likely be installed moving forward); and, 
• additional indoor air testing of some homes may be necessary to ensure that vapor intrusion does not pose a problem.   

While MassDEP was one part of a multi-agency response team, the rapid and impressive deployment of people and equipment helped to minimize the impact of what could have been a tragic and devastating accident.

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