The Big Dig and its Big Effect on the Environment

Erica Wong

Anyone who lives near a major city knows about the pains of traffic jams and commutes that can take hours each way. Boston is no exception; it has suffered from traffic problems ever since its “Central Artery,” which ran through the downtown area, was constructed in 1959. More than 200,000 vehicles traveled on the “Central Artery” daily, which was not built to accommodate such a large number. Thus, in the early 1990s, the Massachusetts Turnpike Authority (MTA) established the Central Artery/Tunnel Project, better known by its nickname “The Big Dig.” Although the Big Dig, slated for completion in 2006, has drastically improved Boston’s transportation woes, it has also greatly affected the surrounding areas, both positively and negatively.

It’s no surprise why Boston is a victim of crowded highways – its location makes it an extremely desirable place to live and work. Not only is it located near several major bodies of water, such as Boston Harbor and the Atlantic Ocean, but it is a highly cosmopolitan city rich in culture, as well as relatively close in proximity to other East Coast hubs of business and the arts, such as New York and Philadelphia. The increase of Boston’s population naturally led to cluttered highways, which subsequently caused more accidents involving motor vehicles and traffic jams that could potentially last up to 16 hours a day. The Big Dig is an attempt to remedy these problems; plans include replacing the current 6-lane elevated highway with an 8-10 lane underground expressway. This expressway would culminate in a 14-lane, two bridge crossing over the Charles River. According to the MTA, the Big Dig is currently 98% completed, which is a substantial achievement – after all, the Big Dig consists of 7.8 miles of highways, all part of a network of current regional highways which must be integrated into those in Boston. However, although the Big Dig might be nearing completion, it would not be farfetched to say that the Dig has had long-term effects on the environment.

The Big Dig required more than 200,000 construction vehicles to carry out construction. Not surprisingly, each of those vehicles would emit toxic fumes from their exhaust pipes, causing air pollution. According to the Environmental Protection Agency, “Construction equipment such as front end loaders, backhoes, bulldozers, cranes, and excavators contributes approximately one quarter of mobile source particulate matter (PM) emissions and ten percent of all oxides of nitrogen (NOx) emissions.” In addition, particulate matter has been named a human carcinogen by the EPA, and diesel particulates have been determined to be a toxic air pollutant by the California Air Resources Board. Not only has the air been affected, the land itself has been degraded. The Big Dig required that 16 million cubic yards of dirt and a million cubic yards of sediment needed to be moved in order to start construction. This could, conceivably, destroy natural habitats for birds and various small mammals. The Big Dig, from an environmental standpoint, seems like a complete and utter disaster – the sheer scale of the project itself suggests great and adverse effects on the environment.

However, the Dig has both directly and indirectly made improvements to the environment; for example, carbon dioxide emissions have decreased. This may sound odd, but under further scrutiny, it makes sense: if traffic moves more smoothly, then cars will not idle on the roads for nearly as long – thus less carbon dioxide will be released. Perhaps one of the biggest improvements to the environment, though, is the case of Spectacle Island.

Spectacle Island, located in Boston Harbor, was a constant eyesore for South Boston residents. It was a landfill which held obscene amounts of garbage, much of which poured into the surrounding waters. The Big Dig provided an opportunity for Bostonians to kill two birds with one stone: take the aforementioned soil and sediment that was extracted in order to create the tunnels, and transport them to Spectacle Island in order to create a new park there. To prevent erosion a dike was created, and a layer of topsoil was deposited on the island so trees and shrubs could be planted on the island. Now, instead of a floating dump, Spectacle Island offers many recreational opportunities to those living in Boston, such as beaches, trails and picnic areas.

The Big Dig has been one of the largest scale improvements in transportation in recent history, if not all of history. The population increase in recent decades leads to a greater need for efficient transportation, and the Big Dig is an example of this. When I visited Boston two summers ago, I was admittedly appalled at the fact that the Dig was quite an eyesore, and it seemed obvious to me that there had to be mass environmental degradation resulting from this project. However, after investigating the Big Dig, it has had many positive effects, not just environmentally but socially, as well (for example, some areas of Boston that were difficult reach with the old highways are now more easily accessible – thus, the city is now more integrated). Throughout history, transportation has been portrayed as something that destroys the integrity of the environment, due to the clearing of forests to make room for railroads or the contribution of toxic fumes into the atmosphere. But under closer examination, transportation, even with all its flaws, is a necessity. Not only does it make the transport of people or goods more efficient, but in the case of Spectacle Island, make other parts of society better.

Works Cited

“The Big Dig.”. 23 March 2006. <>.

“EPA: Voluntary Diesel Retrofit Program - Big Dig - Clean Air Construction.” Environmental Protection Agency. 23 March 2006. <>.

“MTA - The Big Dig.” Massachusetts Transportation Authority. 23 March 2006. <>.


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last updated 3/25/06