Civil Engineering storm water projects benefit base, environment

  • Published
  • By Meredith March
  • 66th Air Base Wing Public Affairs
HANSCOM AFB, Mass. --  Hanscom's civil engineers have proven masterful over the years in keeping the base puddle-free during rain storms by implementing an efficient drainage system which carries excess water away from the streets and into the Shawsheen River.

Downstream flooding and water quality concerns, however, have motivated them to instigate storm water management projects which benefit the aquatic ecosystem and communities along the river in addition to the Hanscom community. Civil Engineering recently completed a project directly addressing concerns about the quantity and quality of Hanscom's storm water drainage.

The headwaters of the Shawsheen River are located in Hanscom's wetlands, and the majority of the base's water drainage goes into the river, said Don Morris, Civil Engineering Environmental director.

Civil Engineering's Clean Water Act compliance studies revealed that the base's storm water system was too effective and the water quality was impaired. "We realized that the system here was so efficient that it got water off base quickly, but also flooded the river quickly. Flooding affects the river's aquatic life and the people downstream," he said.

To reduce the amount of water flowing into the river during the winter and spring months while recharging the ground water flow for the summer months and improve the water's quality, Civil Engineering began utilizing Best Management Practices to manage storm water, Mr. Morris said.

Their most recently completed project is a water quality swale near the entrance to the Motor Pool. A water quality swale is a broad, shallow channel with vegetation covering the side slopes and bottom. The swale collects storm water and prevents it from draining directly into the river, while the vegetation filters pollutants carried into the water from the pavement, Mr. Morris said.

After constructing the swale, David Little, Civil Engineering Heavy Equipment operator, planted cattails along its slopes. "The cattails absorb the petroleum by-products and other pollutants that come off the Motor Pool's concrete," Mr. Morris said.

The water collected in the swale eventually dissipates and goes into the river or infiltrates the soil, Mr. Morris said. "This water still ends up in the river, but that could take months. That is beneficial in the summer when the river potentially could dry up, especially during long dry spells. If we put water in the ground in winter and spring, we will have water in the river in the summer," he said.

Additional storm water controls have been implemented base-wide. "This will be a long-term enhancement to the river ecosystem and we're happy to be doing it. It's the right thing for the environment," Mr. Morris said.