Hydrologic Technician taking a streamgage measurement at USGS 01104415 in the Cambridge Reservoir Watershed, Massachusetts.
Water Quality Monitoring in the Cambridge Drinking-Water Source Area, Massachusetts
The Cambridge Water Department supplies approximately 13 million gallons per day of drinking water to more than 100,000 customers. Raw water is obtained from a serial system of three primary storage reservoirs—Cambridge Reservoir (also known as the Hobbs Brook Reservoir), Stony Brook Reservoir, and Fresh Pond Reservoir—in parts of Cambridge, Lexington, Lincoln, Waltham, and Weston, Massachusetts. These reservoirs receive inflow from more than 13 subbasins within a source area of 23.7 square miles. The Cambridge drinking-water source area contains major transportation corridors including Interstate 95, State Routes 2, 2A, 20, and 117, and commuter railways as well as large impervious areas of industrial, commercial, and residential land use.
The U.S. Geological Survey (USGS) and the Cambridge Water Department have been working together since 1997 on studies and programs designed to ensure that the city’s drinking-water supply is as free of contamination as possible. In 1997–98, the USGS provided an assessment of limnological conditions in the three serial storage reservoirs and described the water-quality conditions in the drinking-water source area. Subsequently, the USGS and Cambridge Water Department designed and implemented a monitoring network for the tributaries flowing into the drinking-water supply reservoirs. Streamflow, water-quality, and meteorological data collected by the USGS from this network are available to the public through the USGS National Water Information System website and in published reports.
From 2004 through 2008, the USGS and Cambridge Water Department characterized water quality during base-flow (conditions generally representing only groundwater discharge) and storm-runoff conditions in four tributaries to the Cambridge and Stony Brook Reservoirs and in the main stem of Stony Brook, the primary source of inflow to the Stony Brook Reservoir. Water-quality conditions were similarly characterized for the period of 2009 through 2015. Currently, the USGS, in cooperation with the Cambridge Water Department, operates water-quality monitoring stations on every major tributary and on the three reservoirs in the drinking-water source area.

Hydrologic Technician taking a streamgage measurement at USGS 01104415 in the Cambridge Reservoir Watershed, Massachusetts.
Loads and yields of deicing compounds and total phosphorus in the Cambridge drinking-water source area, Massachusetts, water years 2009–15
Water quality in the Cambridge, Massachusetts, drinking-water source area, 2005-8
Water-quality conditions, and constituent loads and yields in the Cambridge drinking-water source area, Massachusetts, water years 2005–07
Storms, streams, and reservoirs - Assessing water quality in the Cambridge, Massachusetts, drinking-water source area
Factors affecting reservoir and stream-water quality in the Cambridge, Massachusetts, drinking-water source area and implications for source-water protection
The Cambridge Water Department supplies approximately 13 million gallons per day of drinking water to more than 100,000 customers. Raw water is obtained from a serial system of three primary storage reservoirs—Cambridge Reservoir (also known as the Hobbs Brook Reservoir), Stony Brook Reservoir, and Fresh Pond Reservoir—in parts of Cambridge, Lexington, Lincoln, Waltham, and Weston, Massachusetts. These reservoirs receive inflow from more than 13 subbasins within a source area of 23.7 square miles. The Cambridge drinking-water source area contains major transportation corridors including Interstate 95, State Routes 2, 2A, 20, and 117, and commuter railways as well as large impervious areas of industrial, commercial, and residential land use.
The U.S. Geological Survey (USGS) and the Cambridge Water Department have been working together since 1997 on studies and programs designed to ensure that the city’s drinking-water supply is as free of contamination as possible. In 1997–98, the USGS provided an assessment of limnological conditions in the three serial storage reservoirs and described the water-quality conditions in the drinking-water source area. Subsequently, the USGS and Cambridge Water Department designed and implemented a monitoring network for the tributaries flowing into the drinking-water supply reservoirs. Streamflow, water-quality, and meteorological data collected by the USGS from this network are available to the public through the USGS National Water Information System website and in published reports.
From 2004 through 2008, the USGS and Cambridge Water Department characterized water quality during base-flow (conditions generally representing only groundwater discharge) and storm-runoff conditions in four tributaries to the Cambridge and Stony Brook Reservoirs and in the main stem of Stony Brook, the primary source of inflow to the Stony Brook Reservoir. Water-quality conditions were similarly characterized for the period of 2009 through 2015. Currently, the USGS, in cooperation with the Cambridge Water Department, operates water-quality monitoring stations on every major tributary and on the three reservoirs in the drinking-water source area.

Hydrologic Technician taking a streamgage measurement at USGS 01104415 in the Cambridge Reservoir Watershed, Massachusetts.
Hydrologic Technician taking a streamgage measurement at USGS 01104415 in the Cambridge Reservoir Watershed, Massachusetts.