BASF technology cleans up Boston's big dig project

The Big Dig construction project in Boston consists of a total of 160 lane miles of new highway in a 7.5-mile long corridor, half of which are tunnels. Construction included about 13 million cubic yards of excavated earth material and 4 million cubic yards of concrete hauled by over half a million truckload trips. During mainline construction, hundreds of pieces of heavy equipment were used 24 hours a day, including large excavators, front-end loaders, bulldozers, cranes, cement trucks, and both 10-wheel and 18-wheel dump trucks.

The roughly 200,000 pieces of construction equipment operating in the northeast account for close to 25% of the PM10 (particulate matter 10 micrometers in size) emissions from all sources. The reduction of these emissions has the potential to both improve ambient air quality for the region and to especially to the people living near the construction zone.  So the Massachusetts Turnpike Authority and the Northeast States Coordinated Air Use Management (NESCAUM) association undertook the Big Dig Diesel Emissions Reduction Project.

The goal of the Big Dig Diesel Emissions Reduction Project was to reduce emissions near homes, hospitals, underground construction areas and fresh air intakes. The project included retrofitting construction equipment with diesel oxidation catalysts (DOCs) and diesel particulate filters (DPFs). BASF supplied diesel oxidation catalysts and BASF DPX™ diesel particulate filters for this project. According to contractor experience, the equipment retrofitted with catalysts did not suffer any loss of power or require any additional fuel or maintenance.

The Big Dig Diesel Construction Retrofit Program has proven that retrofitting construction equipment with catalysts is very feasible, and can also significantly lower emissions, odors, and visible smoke.  Moreover, considering that the cost of oxidation catalysts is a small fraction of the total equipment-retrofitting costs, the program is also very cost effective. Best of all, the retrofitted equipment showed an approximate reduction of 36 tons/year for carbon monoxide, 12 tons per year of hydrocarbons, and 3 tons per year of particulate matter.