5. Stormwater Management

The EPA Storm Water Phase II Final Rule requires a regulated storm sewer system to obtain National Pollutant Discharge Elimination System (NPDES) permit coverage because the storm water discharges are considered "point sources" of pollution. These storm sewers are considered point sources because they discharge storm water into discrete conveyances, including roads with drainage systems and municipal streets. Most storm sewers are publicly owned or operated and are designed or used for collecting or conveying storm water. Once a municipality submits a permit application and permit coverage is obtained, it must satisfy the conditions of the permit and submit periodic reports on the status and effectiveness of the program at reducing pollutants to the maximum extent practicable.

There are three municipalities in the watershed that fall under this EPA Phase II requirement: they are Waltham, Lexington, and Weston.  The CWD is working closely with these municipalities to insure that measures are taken to reduce pollutant loads from storm water discharges in the municipality that are close to or directly tributary to the Cambridge water supply.