Moon Island

Situated in the middle of Quincy Bay is the 54-acre peninsula Moon Island. One of the five peninsulas in the harbor, Moon Island has been connected to Squantum via a causeway since the 1870s. It boasts a single drumlin that has one of the highest elevations in the harbor at 98 feet above sea level. Sumac groves and meadow grasses can be found throughout the peninsula. Owned and managed by City of Boston, Moon Island serves as a training site for the Boston Fire Department and hosts a shooting range for the Boston Police Department. For these reasons, visitation to Moon Island is prohibited.

Similar to many of the other islands in the harbor, local Indigenous peoples likely accessed Moon Island seasonally. After European colonization, settlers used the island as farmland. Colonial troops mustered in on the island during the Siege of Boston in the early years of the American Revolution.

In 1878, the City of Boston acquired the island and began work on a massive sewerage project that drastically changed the topography of the island. By its completion in 1884, the project cost 6 million dollars, over 180 million in today’s dollars. The project focused on putting a drainage system at south end of the Charles River with an outlet that led to Moon Island. Moon Island had been selected after preliminary tests showed that the area had a “favorable ebb current.” Some sewers went directly to Moon Island, while other main sewers stopped first at pumping stations and then diverted to Moon Island.

One of these pumping stations, called the Calf Pasture Pumping Station, began operating in 1884. It worked by screening wastewater and then pumping the sewage through a mile long tunnel under the Neponset River to Moon Island. On the island, a reservoir that stretched five acres held waste in four granite tanks until the tide got high enough for the waste to be released further out into the harbor. These efforts pushed the sewage far enough out into the harbor that the water quality in the inner harbor improved and made popular activities like swimming and yachting more enjoyable.

Construction of a garbage reclamation plant took place in 1892, but the plant relocated to Spectacle Island in 1912. In 1951, the City of Boston completed the construction of a bridge that connected nearby Long Island to Moon Island. In the following years the Boston Fire Department installed their training facility on the island. The sewerage plant did not close until the 1970s. Since its closure, the main use of the island became the training facility that is still present on the island today.

https://www.nps.gov/places/moon-island.htm