The City of Lebanon, NH is responsible for maintaining extensive infrastructure including streets, storm drainage facilities, and subsurface utilities. In 2000, the City was faced with an Administrative Order from EPA to reduce combined sewer overflows (CSO) followed by a Consent Decree in 2009 which drove what has been two decades worth of extensive infrastructure improvements and over 13 miles of stormwater infrastructure.

Throughout the past two decades, the City has worked hand-in-hand with Wright-Pierce and the New Hampshire Department of Environmental Services (NHDES) to resolve inflow/infiltration (I/I) and CSO issues and make the surrounding waterways cleaner and safer. The CSO program consists of 13 separate contracts totaling over $60M in construction costs. The scope and scale of the project includes ~14.5 miles of roadway improvements, ~18 miles of sidewalks, ~12.5 miles of sewer infrastructure, ~13.5 miles of stormwater infrastructure, and ~12.6 miles of water infrastructure and has removed an estimated 250 catch basins from the collection system. This CSO program is coming to completion as the last contract, number 13, kicks off construction in Fall of 2021.

The journey of the Lebanon CSO Program has included significant fieldwork (flow monitoring, CCTV, manhole inspections, smoke testing, dye testing, and house-to-house inspections) and many innovative stormwater treatment initiatives (porous pavement as shown in the featured photo, rain gardens, curb inlet filters, and proprietary stormwater treatment units). Several of the recent contracts included major public education initiatives including resident public meetings, resident “walkabouts”, and spots on the local public access television station.

Watch this video to hear perspectives from the City of Lebanon, NHDES, and Wright-Pierce as this program comes to a close. If you want to learn more about implementing a CSO program like this in your community, please contact us.