The City of Boston was formed by filling lowlands to connect the “Trimountaine,” the three hills, used by early settlers to describe the land. In the centuries since, many of the area’s island formations became mainland. The City of Boston, as we know it today, still includes several islands in Boston Harbor—the largest of which is Long Island. Long Island is positioned adjacent to Moon Island and is often obscured from view by the South Boston skyline and by Spectacle Island and Thompson Island. Long Island has been used by the City of Boston for numerous governmental and institutional purposes over the decades, but without any residences on the island, it is often overlooked as a part of the City. Since 1951, a two-lane viaduct has connected the 225-acre island to the mainland via Moon Island and a causeway connected to the City of Quincy. However, in October of 2014, the 3,450-foot, steel-truss Long Island Bridge was closed and deemed unsafe for travel, once again separating Long Island from the mainland.
The bridge and the utility infrastructure it supported, which included the island’s water supply, were soon scheduled for removal beginning in February 2015. Installation of new subaqueous utility connections for the island would not be completed until late fall 2015, and given the sudden closure of the bridge there were no provisions for temporary water or electric service. Water stored in the one-million-gallon tank at the center of the island would supply the island temporarily, but the City needed a plan to refill the tank as water was used. The island’s water system provided potable water and fire protection to a Boston Public Health Commission (BPHC) campus, a summer camp for kids from the City of Boston, and a visitor center, marina, and café operated by the state on nearby Spectacle Island.
The water challenge suddenly becomes immediate
The water supply situation on the island became precarious when, on January 15, 2015, the water main on the Long Island Bridge froze and ruptured due to lack of flow, rendering the island without a water supply several weeks ahead of the planned schedule. The water level in the island’s water tank began to drop, limiting fire protection capabilities.
The City of Boston engaged Woodard & Curran to determine how to provide the island with emergency water supply for domestic use and fire protection until a new water supply line could be installed under Boston Harbor from the mainland. We evaluated the City’s limited alternatives, including a temporary HDPE water supply main on the harbor floor, a desalination system, and using a barge to deliver water. The option to supply non-potable water for fire protection and separately supply bottled water was also considered. Given the permitting, schedule, and regulatory requirements, the City agreed with Woodard & Curran’s findings that delivering potable water by barge in a tank and pumping into the island’s system was the only viable option. We also worked with the Massachusetts Department of Environmental Protection throughout the alternatives evaluation to ensure a rapid permitting process for the selected alternative.
Implementing the emergency plan
Woodard & Curran was then hired to design, permit, and coordinate construction of the necessary temporary infrastructure. We administered the water delivery and construction similar to a turnkey approach for the City of Boston. In the seven days following the Notice-to-Proceed, Todd Prokop—a Project Engineer at Woodard & Curran with significant experience in drinking water distribution system and treatment process design for clients in the municipal and private sectors—led the effort to design the system and coordinate with five major contractors to install the permanent and temporary infrastructure required to accommodate water deliveries to the island. Our work also included obtaining permit approval for the barging operations, arranging for the filling, transport, and offloading of the water, and providing ongoing water quality sampling on the island required by MassDEP.
To begin water deliveries to the island, temporary water lines had to be installed on both the mainland and the island. An existing hydrant was used to fill a 21,000-gallon potable water tank positioned on a barge, and a diesel-powered pump on the barge was used to transfer water from the tank to an identical tank located on the island. A second diesel pump was used to move water from the shore-based tank through more than 3,000 feet of temporary HDPE water main to the existing water storage standpipe.
A number of obstacles increased the difficulty of the project once work began. For example, the existing water tank on the island needed repair, and 18 inches of ice was discovered in the tank, in May, thus reminding us all that the winter of 2014/15 was a very difficult one for Boston. With no bridge access to the island, all personnel, materials, and equipment necessary to perform the work were brought to the island via beach-access barge or chartered skiff. Installation and repair work, including repair of the steel standpipe floor plates and installation of additional gate valves to allow water feed to nearby Spectacle Island, required numerous site visits—many 12-16 hours in length—in order to minimize transportation costs and meet the client’s schedule.
Water shipments begin
With fast-tracked regulatory approvals and infrastructure in place, full-time, regular shipments of water began on May 11th and continued from sun-up to sun-down for 12 consecutive days. Todd coordinated the activities of the barge, tug boat, and support skiff, as well as engineering support staff, Massachusetts-certified operations staff, laboratory runners for sample delivery, BPHC staff on Long Island, and Department of Conservation and Recreation staff on Spectacle Island. Each day’s work was scheduled around available daylight, Coast Guard captain’s license shift limits, low-tide periods when tank fill up was not possible, last-minute cancellations of the support skiffs, and ever-changing marine forecasts. Over 900,000 gallons of water was delivered to the island during the initial filling phase, establishing the required 80-foot water level in the island’s previously empty standpipe.
Over the remainder of the spring and summer, Woodard & Curran coordinated 22 additional days of water deliveries, including deliveries three days per week during the peak summer demand to maintain the tank’s water level. Working with City of Boston, MassDEP, and BPHC staff, we met all regulatory requirements, experienced no safety incidents, and delivered over 2.5 million gallons of water in 122 individual loads to the island, each under the supervision of a state-certified Drinking Water Treatment Operator.
The permanent subaqueous water main reestablishing a land-based water supply to Long Island and Spectacle Island was completed in November, 2015. Since that time, all temporary infrastructure has been removed, and all facilities on both islands have returned to normal operation.
The project’s success resulted from the collaborative approach embraced by the City of Boston and BPHC teams, the regulatory community, and Woodard & Curran. Each played a major role in ensuring that summer activities across the Boston Harbor Islands could proceed as planned, with no inconvenience or safety risk to the public.
