"Hazel" Arrives in Alexandria

Hazel, a 380-ton, 14’ 8” tunnel boring machine, will play a key role in Alexandria’s largest infrastructure project to date. RiverRenew is a $665-million program to remediate longstanding combined sewer overflow issues and improve the quality of city waterways. The tunnel boring machine is named Hazel in recognition of environmental justice pioneer Hazel Johnson, who died in 2011. Alexandrians chose her for the naming in an online poll that included five others who made outstanding contributions to the city, the environment, engineering, or construction fields. Making its way from Schwanau, Germany, to Alexandria, a welcome reception was held on July 14 to celebrate Hazel’s arrival, with over 100 attendees.

Hazel’s arrival and dedication is a major milestone for RiverRenew and a critical part of meeting a state-mandated deadline to remediate combined sewer overflows by 2025. Once lowered more than 100 feet below ground, Hazel will build the new two-mile, 12-ft wide tunnel with little service interruption on a journey estimated to take just over a year to complete. After completion, the RiverRenew tunnel system will be designed to prevent over 120 million gallons of combined sewage from polluting the Potomac River, Hunting Creek, and Hooffs Run each year during heavy rain events. Sewage stored in the tunnel will gradually be released to the city’s Water Resource Recovery Facility for treatment and subsequent discharge to the Potomac River.

For additional information regarding the project as well as Hazel, visit the RiverRenew website.