Hydrologic, Water-Quality, and 

Meteorological Data for the Cambridge, 

Massachusetts, Drinking-Water Source 

Area, Water Year 2005

By Kirk P. Smith

Prepared in cooperation with the

City of Cambridge, Massachusetts, Water Department

Open-File Report 2007–1049

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

For product and ordering information:

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U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Smith, K.P., 2007, Hydrologic, water-quality, and meteorological data for the Cambridge, Massachusetts, drinkingwater source area, water year 2005: U.S. Geological Survey Open-File Report 2007–1049, 119 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................2

Purpose and Scope ..............................................................................................................................2

Description of Monitoring Network...................................................................................................2

Continuous Data Collection and Computation ..........................................................................................5

Hydrologic Data.....................................................................................................................................5

Water-Quality Data...............................................................................................................................6

Meteorological Data.............................................................................................................................6

Sample Collection and Analysis..................................................................................................................6

Presentation of Data......................................................................................................................................8

Station History.......................................................................................................................................8

Streamflow Data ...................................................................................................................................8

Data Table of Daily Mean Values ..............................................................................................8

Annual Summary Statistics........................................................................................................8

Reservoir Data.......................................................................................................................................8

Meteorological and Water-Quality Data...........................................................................................8

Water-Quality Data...............................................................................................................................9

Data for the Cambridge Drinking-Water Source Area ............................................................................9

Surface-Water Data .............................................................................................................................9

Water-Quality Data...............................................................................................................................9

Water Samples....................................................................................................................................20

Meteorological Data...........................................................................................................................21

References Cited..........................................................................................................................................27

Glossary.......................................................................................................................................................115

Figures

1. Map showing the monitoring network for the Cambridge, Massachusetts, 

drinking-water source area for water year 2005, eastern Massachusetts ........................3

2–10. Graphs showing:

2. The percentage of water supplied from the Hobbs Brook basin relative to 

the total water entering the Stony Brook Reservoir compared to the 

percentage of water discharged from the Stony Brook Reservoir to the 

Charles River relative to the total inflow for water year 2005, eastern 

Massachusetts...................................................................................................................14

3. Monthly mean reservoir-storage capacities for water year 2005 shown as 

percent capacity for the Cambridge Reservoir, Stony Brook Reservoir, and 

Fresh Pond Reservoir, eastern Massachusetts............................................................14

4. Monthly mean specific conductance for water year 2005 for USGS station 

01104430, Hobbs Brook below Cambridge Reservoir near Kendal Green, 

Massachusetts, compared to the period-of-record maximum and minimum 

monthly mean specific conductance, and the median monthly specific 

conductance for water years 1997–2004.......................................................................15
iv

Tables

1. Names, locations, drainage areas, and periods of record for U.S. Geological 

Survey monitoring stations in the drinking-water source area for Cambridge, 

Massachusetts, for water year 2005 .........................................................................................4

2. Hydrological, water-quality, and meteorological parameters measured at each 

continuous-monitoring station during water year 2005, eastern Massachusetts.............5

3. Rating classifications for continuous records of hydrologic, water quality, and 

meteorological parameters.........................................................................................................6

4. Extreme measurements of physical parameters for U.S. Geological Survey 

stations in the drinking-water source area for Cambridge, Massachusetts....................10

5. Extreme and median constituent concentrations measured in water samples for 

U.S. Geological Survey monitoring stations in the drinking-water source area 

for Cambridge, Massachusetts, for the period of record ....................................................12

6. Characteristics of selected pesticides detected in base-flow and stormflow 

water samples collected in the Hobbs Brook and Stony Brook Reservoir basins, 

eastern Massachusetts, for water year 2005 ........................................................................22

7. Frequency of detection and maximum concentration of selected pesticides 

detected in base-flow and stormflow water samples collected in the Hobbs 

Brook and Stony Brook Reservoir basins, eastern Massachusetts, for 

water year 2005...........................................................................................................................24

8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey 

stations in the drinking-water source area for Cambridge, Massachusetts, for 

water year 2005...........................................................................................................................32

5. Monthly mean specific conductance for water year 2005 for USGS station 

01104460, Stony Brook at Route 20 at Waltham, Massachusetts, compared 

to the period-of-record maximum and minimum monthly mean specific 

conductance, and the median monthly specific conductance for water 

years 1997–1998 and 2002–2004 ......................................................................................16

6. Daily mean specific-conductance values for USGS station 422302071083801, 

Fresh Pond Reservoir at Cambridge, Massachusetts, for water year 2005.............17

7. (A) Daily total flows greater than 0.01 million gallons per day, and (B) daily 

maximum and daily minimum specific conductance values for USGS station 

01104415, Cambridge Reservoir, unnamed tributary 2, near Lexington, 

Massachusetts, for water year 2005 ..............................................................................18

8. Monthly mean specific conductance for water year 2005 for USGS station 

01104455, Stony Brook, unnamed tributary 1, near Waltham, Massachusetts, 

compared to the period-of-record maximum and minimum monthly mean 

specific conductance, and the median monthly specific conductance for 

water years 1998–2004......................................................................................................19

9. Monthly precipitation totals for the Cambridge Reservoir, Stony Brook 

Reservoir, and Fresh Pond Reservoir in the Cambridge, Massachusetts, 

drinking-water source area for water year 2005..........................................................25

10. Monthly mean air temperatures for water year 2005 for the Cambridge 

Reservoir, compared to the period-of-record maximum and minimum 

monthly mean air temperatures and the median monthly air temperatures 

for water years 2002–2004, eastern Massachusetts ...................................................26
v

9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological 

Survey station numbers 01104430, Cambridge Reservoir near Kendal Green, 

01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005...........................................45

10. Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological 

Survey stations 01104430, Hobbs Brook below Cambridge Reservoir near Kendal 

Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, 

Fresh Pond Reservoir at Cambridge, Massachusetts, for water year 2005......................51

11. Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey 

station numbers 01104430, Cambridge Reservoir near Kendal Green, 01104480, 

Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond Reservoir at 

Cambridge, water year 2005 .....................................................................................................57

12. Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey 

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook 

Reservoir in Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, 

Massachusetts, for water year 2005 .......................................................................................63

13. Daily, monthly, and annual statistics for water temperature for U.S. Geological 

Survey stations in the drinking–water source area for Cambridge, Massachusetts, 

for water year 2005.....................................................................................................................75

14. Daily, monthly, and annual statistics for specific conductance for U.S. Geological 

Survey stations in the drinking-water source area for Cambridge, Massachusetts, 

for water year 2005.....................................................................................................................87

15. Physical properties and concentrations of major inorganic constituents, nutrients, 

trace metals, suspended sediments, Escherichia coli bacteria, polyaromatic 

hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow 

water samples collected in four subbasins and the Fresh Pond intake structure 

in the Cambridge, Massachusetts, drinking-water source area for water year 2005 ....99

16. Concentrations of Escherichia coli for water samples collected during base flow 

and storms in four subbasins in the Cambridge, Massachusetts, drinking-water 

source area for water year 2005 ............................................................................................114
vi

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25,400 micron (μm)

inch (in.) 25,400,000 nanometer (nm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square mile (mi2) 2.590 square kilometer (km2) 

Volume

million gallons (Mgal) 3785.4 cubic meter (m3)

Flow rate

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

 °F=(1.8×°C)+32

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Water- and sediment-quality constituents are expressed in milligrams per liter (mg/L), 

micrograms per liter (μg/L), parts per million (ppm), and parts per billion (ppb). Milligrams per 

liter is a unit expressing the concentration of chemical constituents in solution as weight 

(milligrams) of solute per unit volume (liter) of water. One thousand milligrams per liter is 

equivalent to one gram per liter. One thousand micrograms per liter is equivalent to one 

milligram per liter. For concentrations less than 7,000 mg/L, the numerical value is the same as 

for concentrations in ppm. 

Specific conductance of water is expressed in microsiemens per centimeter at 25 degrees 

Celsius (μS/cm at 25°C).

Abbreviations

ASTM American Society for Testing and Materials

COV coefficient of variation

CWD City of Cambridge, Massachusetts, Water Department

EMC event mean concentration

ISO International Organization for Standardization

NIST National Institute of Standards and Technology

PAH polyaromatic hydrocarbons

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

WY water year

Conversion Factors, Datum, and Abbreviations
Abstract

Records of water quantity, water quality, and meteorological parameters were continuously collected from three 

reservoirs, two primary streams, and four subbasin tributaries 

in the Cambridge, Massachusetts, drinking-water source area 

during water year 2005 (October 2004 through September 

2005). Water samples were collected during base-flow conditions and storms in the subbasins of the Cambridge Reservoir 

and Stony Brook Reservoir drainage areas and analyzed for 

selected elements, organic constituents, suspended sediment, 

and Escherichia coli bacteria. These data were collected to 

assist watershed administrators in managing the drinkingwater source area and to identify potential sources of contaminants and trends in contaminant loading to the water supply.

Monthly reservoir capacities for the Cambridge Reservoir 

varied from about 59 to 98 percent during water year 2005, 

while monthly reservoir capacities for the Stony Brook 

Reservoir and the Fresh Pond Reservoir were maintained 

at capacities greater than 84 and 96 percent, respectively. 

Assuming a water demand of 15 million gallons per day by 

the city of Cambridge, the volume of water released from the 

Stony Brook Reservoir to the Charles River during the 2005 

water year is equivalent to an annual water surplus of about 

119 percent. Recorded precipitation in the source area for 

the 2005 water year was within 2 inches of the total annual 

precipitation for the previous 2 water years.

The monthly mean specific conductances for the outflow 

of the Cambridge Reservoir were similar to historical monthly 

mean values. However, monthly mean specific conductances 

for Stony Brook near Route 20, in Waltham (U.S. Geological Survey station 01104460), which is the principal tributary 

feeding the Stony Brook Reservoir, were generally higher than 

the medians of the monthly mean specific conductances for 

the period of record. Similarly, monthly mean specific conductances for a small tributary to Stony Brook (U.S. Geological Survey station 01104455) were generally higher than the 

medians of the monthly mean specific conductances for the 

period of record. The annual mean specific conductance for 

Fresh Pond Reservoir increased from 514 microsiemens per 

centimeter (μS/cm) in the 2004 water year to 553 μS/cm for 

the 2005 water year.

Water samples were collected from four tributaries during 

base-flow and stormflow conditions in December 2004, and 

July, August, and September 2005 and analyzed for suspended 

sediment, 6 major dissolved ions, total nitrogen, total phosphorus, 8 total metals, 18 polyaromatic hydrocarbons (PAHs), 

61 pesticides and metabolites, and Escherichia coli bacteria. 

Concentrations for most dissolved constituents in samples 

of stormwater were generally lower than the concentrations 

observed in samples collected during base flow; however, concentrations of total phosphorus, PAHs, suspended sediment, 

and some total recoverable metals were substantially greater in 

stormwater samples.

Concentrations of dissolved chloride and total recoverable manganese in water samples collected during base-flow 

conditions from three tributaries exceeded the U.S. Environmental Protection Agency (USEPA) secondary drinking 

water standards of 250 and 0.05 milligrams per liter (mg/L), 

respectively. Concentrations of total recoverable manganese 

exceeded the secondary drinking water standard in samples of 

stormwater from each tributary. Concentrations of total recoverable iron in water samples exceeded the USEPA secondary 

drinking water standard of 0.3 mg/L periodically in water 

samples collected at USGS stations 01104415, 01104455, and 

01104475, and consistently in all water samples collected at 

USGS station 01104433.

Concentrations of Escherichia coli bacteria in water 

samples collected during base flow ranged from 4 to 1,400 

colony-forming units per 100 milliliters (col/100mL). Concentrations of Escherichia coli bacteria in composite samples 

of stormwater ranged between 1,700 to 43,000 col/100mL 

with the highest concentrations measured at USGS station 

01104475.

Fluoranthene and pyrene were the most commonly detected PAHs in water samples collected during base flow. Concentrations of PAH compounds observed in composite samples 

of stormwater were often as much as an order of magnitude or 

more than concentrations measured in water samples collected 

during base flow. Fluoranthene, phenanthrene, and pyrene 

were the only PAH compounds found in a water sample 

collected from the Fresh Pond Reservoir intake structure. 

Concentrations of 16 pesticides and caffeine were measured in 

water samples collected in four subbasins and in Fresh Pond 

Hydrologic, Water-Quality, and Meteorological Data 

for the Cambridge, Massachusetts, Drinking-Water 

Source Area, Water Year 2005

By Kirk P. Smith
Reservoir. Caffeine, imidacloprid, and siduron were the most 

frequently detected compounds. Each of these compounds 

also was detected in water collected from the Cambridge 

water-treatment facility raw-water intake at the Fresh Pond 

Reservoir. Compounds including 3-ketocarbofuran, carbaryl, 

MCPA, propoxur, siduron, and triclopyr were only detected in 

water samples of stormwater.

Introduction

Hydrologic and water-quality monitoring is important 

for the effective management and protection of drinking-water 

supplies. Both the quantity and quality of water are monitored 

because these factors determine the physical, chemical, and 

biological state of the water supply. Without accurate information on the past and current condition of the water supply, 

effective preservation and remediation programs cannot be 

implemented or evaluated.

The U.S. Geological Survey (USGS) works closely with 

municipal water suppliers throughout the nation to address 

specific water problems by conducting hydrologic- and 

water-quality-monitoring programs and detailed investigations 

(Patterson, 1997). One such program, conducted from 1997 

through 1998 by the USGS in cooperation with the City of 

Cambridge, Massachusetts, Water Department (CWD), was 

designed to identify sources of contaminants in the drinkingwater source area for the city (Waldron and Bent, 2001). 

Subsequently the USGS, in cooperation with the CWD, 

designed and implemented a water-monitoring network in the 

drinking-water source area. Data from this network has been 

published annually in various USGS reports (Smith, 2005; 

Socolow and others, 1999, 2000, 2001, 2002, 2003, and 2004).

The CWD supplies approximately 15 millions of gallons 

per day1

 (Mgal/d) to more than 100,000 customers. Most 

of this water is obtained from three primary storage reservoirs (Cambridge Reservoir–also known as the Hobbs Brook 

Reservoir, Stony Brook Reservoir, and Fresh Pond Reservoir), 

in parts of Lexington, Lincoln, Waltham, Weston, and in 

Cambridge (fig. 1). The drainage basin for the Cambridge 

Reservoir includes Hobbs Brook and three unnamed tributaries 

that discharge directly into the reservoir. Water is discharged 

from the southern end of the Cambridge Reservoir into Hobbs 

Brook which receives additional water by an unnamed tributary about a half mile below the reservoir. Hobbs Brook joins 

with Stony Brook about 1.6 miles downstream of the reservoir 

and flows south to the Stony Brook Reservoir. Two unnamed 

tributaries flow into Stony Brook about a quarter mile north 

of the Stony Brook Reservoir. In addition to water from Stony 

Brook, an unnamed tributary flows directly into the Stony 

Brook Reservoir on the southwest side of the reservoir. Additional water enters both reservoirs from other minor tributaries 

and highway and parking-lot storm drains. Water from Stony 

1

 Terms listed in the glossary at the back of this report are in bold type 

where first used in the text.

Brook Reservoir is piped through an aqueduct by the CWD 

directly to Fresh Pond Reservoir where it is stored prior to 

treatment. Overflow and controlled discharges from the Stony 

Brook Reservoir flow into the Charles River in Waltham.

The drainage basin contributing water to these 

reservoirs has undergone rapid development in recent years 

and encompasses major transportation corridors, as well 

as large areas of industrial, commercial, and high-density 

residential land use. Because the City of Cambridge owns 

less than 5 percent of the land in the basin contributing to its 

water-supply system, the CWD relies heavily on monitoring 

to provide information for optimizing the management of 

its reservoirs for water quality and quantity. The USGS 

monitoring network provides near-real-time information 

that assists the CWD in responding rapidly to water-quality 

changes caused by accidental or intentional contamination. 

This information also benefits the CWD, other municipalities, 

and state agencies involved with water-resource development 

and management in the Charles River Basin by enhancing 

their understanding of the relation between local drinkingwater-management practices and regional issues of water 

supply and hydrologic-system response.

Purpose and Scope

This report presents records of water quantity, water quality, and meteorological parameters collected in the Cambridge, 

Massachusetts, drinking-water source area during water year

2005 (October 2004 through September 2005). It describes the 

monitoring network, data-collection methods for all types of 

data, and computation methods. It also describes the chemical 

characteristics of water samples collected during base-flow

conditions and during storms from an unnamed tributary in the 

Cambridge Reservoir basin and three unnamed tributaries in 

the Stony Brook Basin, and of water samples collected from 

the Cambridge water-treatment facility.

Description of Monitoring Network

Stations installed and operated by the USGS in the 

drinking-water source area continuously monitored various 

hydrologic, water-quality, and meteorological parameters 

including stream stage, stream water temperature, stream 

specific conductance, reservoir altitude, air temperature, 

and precipitation. Stations were selected for continuous 

monitoring on the basis of the necessity for water-supply 

regulation by the CWD and of information gained in 

previous USGS investigations that identified specific areas 

as potentially important sources of contaminants. Attributes 

of the monitoring stations are listed in table 1; locations of 

stations selected for continuous monitoring are shown in 

figure 1.

2 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Figure 1. The monitoring network for the Cambridge, Massachusetts, drinking-water source area for water year 

2005, eastern Massachusetts.

Lincoln

LEXINGTON

LINCOLN

WALTHAM

WESTON

01104415

01104410

01104405

01104420

01104430

01104433

01104455

01104460

01104475

01104480

0

0

1

1

2 MILES

2 KILOMETERS

Base from U.S. Geological Survey, 

MassGIS, Cambridge Water Department, 

Harvard Design and Mapping, and Boston Edison. 

EXPLANATION

01104460

MAJOR BASINS

 Hobbs Brook Reservoir

 Stony Brook Reservoir

FORESTED AND NONFORESTED 

 WETLANDS

TOWN BOUNDARY

BASIN BOUNDARY

SUBBASIN BOUNDARY

CONTINUOUS-MONITORING 

 STATION AND NUMBER

71°15'

42°

22'

30"

71°19'

42°

27'

Hobbs Brook

Trapelo Road

128 Cherry Brook

Stony Brook

Hobbs Brook

2A

2

95

Cambridge

Reservoir

Stony Brook

Reservoir 20

Sandy

Pond

117

42°

73° 72° 

71°

70°

MASSACHUSETTS

41°30'

42°30'

0

0

50 KILOMETERS

50 MILES

MASSACHUSETTS

CAMBRIDGE

NEWTON

WALTHAM

LINCOLN

LEXINGTON WINCHESTER

WESTON

MEDFORD

ARLINGTON

BELMONT

128

2

2A

20

117

95

90

Aqueduct to Fresh PondAqueduct to Fresh Pond

Hobbs Brook

Reservoir

Subbasin

Stony Brook

Reservoir

Subbasin

PAYSON PARK

RESERVOIR

Aqueduct to Fresh Pond

STONY BROOK

RESERVOIR

FRESH

POND

HOBBS BROOK

RESERVOIR

CHARLES RIVER

42o

26'

71o 71 08' o

19'

42o

20'

0

0

5 MILES

5 KILOMETERS

422302071083801 

Introduction 3
Stream-stage measurements were recorded at monitoring 

stations at the outlet of the Cambridge Reservoir, on Stony 

Brook, and at the outlet of Stony Brook Reservoir (USGS 

stations 01104430, 01104460 and 01104480). Water-quality 

measurements at the outlet of the Cambridge Reservoir and 

Stony Brook were recorded at USGS stations 01104430 and 

01104460. Physical parameters monitored at these sites are 

listed in table 2. These data were recorded at a frequency of 

15 minutes and were uploaded to a USGS database on an 

hourly basis by phone modem. In addition to measurements 

made on these streams, stream-stage measurements and waterquality measurements were recorded at monitoring stations 

on four of the small tributaries (USGS stations 01104415, 

01104433, 01104455, and 01104475). Because the drainage

areas of these sites are small (less than a square mile) and 

contain many roadways, parking lots, and other impervious 

surfaces (Waldron and Bent, 2001), the hydrologic responses, 

and often the water-quality responses, change rapidly. To 

document these responses effectively, the monitoring stations 

recorded stream-stage and water-quality measurements at 

variable frequencies, as often as 1 minute. These data were 

uploaded to a USGS database on an hourly basis by digital 

cellular modem.

Measurements of reservoir altitude, precipitation, and 

air temperature were recorded at the Cambridge, Stony 

Brook, and Fresh Pond Reservoirs (USGS stations 01104430, 

01104480, and 422302071083801). Water-quality measurements of reservoir water also were recorded at the Fresh Pond 

Reservoir. Physical parameters monitored at these sites are 

listed in table 2. These data were recorded at a frequency of 

15 minutes and were uploaded to a USGS database on an 

hourly basis by phone modem.

Table 1. Names, locations, drainage areas, and periods of record for U.S. Geological Survey monitoring stations in the drinkingwater source area for Cambridge, Massachusetts, for water year 2005.

[USGS, U.S. Geological Survey. °, degree; ', minute; ", second; mi2, square mile]

Station name USGS station 

number Latitude Longitude Drainage area (mi2

) Period of record

Stony Brook at Kendal Green 01104390 42°22'36" 71°16'55" 10.4 03/07/97–09/17/98

Hobbs Brook at Mill Street near Lincoln 01104405 42°26'11" 71°16'12" 2.16 03/05/97–09/16/98

Cambridge Reservoir, unnamed tributary 1, 

near Lexington

01104410 42°26'15" 71°15'53" 2.1 03/05/97–09/16/98

Cambridge Reservoir, unnamed tributary 2, 

near Lexington

01104415 42°26'09" 71°15'38" .41 10/22/97–09/22/98; 

10/01/00–current year

Cambridge Reservoir, unnamed tributary 3, 

near Lexington

01104420 42°25'11" 71°15'29" .73 04/09/97–09/16/98

Hobbs Brook below Cambridge Reservoir 

near Kendal Green

01104430 42°23'53" 71°16'26" 6.86 04/09/97–09/16/98

Hobbs Brook, unnamed tributary 1 

near Kendal Green

01104433 42°23'28" 71°16'18" .36 10/23/97–09/15/05; 

06/28/04–current year

Hobbs Brook at Kendal Green 01104440 42°22'39" 71°16'52" 8.47 03/07/97–10/28/98

Stony Brook, unnamed tributary 1 

near Waltham

01104455 42°22'21" 71°16'15" .48 10/22/97–09/22/98; 

10/01/00–current year

Stony Brook at Route 20 near Waltham 01104460 42°21'08" 71°16'16" 22 03/07/97–10/28/98; 

05/14/02–current year

Stony Brook Reservoir, unnamed tributary 1 

near Weston

01104475 42°21'16" 71°16'07" .85 12/17/97–09/17/98; 

08/26/04–current year

Stony Brook Reservoir at dam near Waltham 01104480 42°21'20" 71°15'56" 23.7 03/1997–current year

Fresh Pond in gate house at Cambridge 422302071083801 42°23'02" 71°08'38" 0 1998; 10/01/03–current year

4 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Continuous Data Collection and 

Computation

The monitoring network provides near-real-time information used to manage the quantity and quality of water in 

the CWD drinking-water source area. At each station, permanently installed analytical equipment automatically measures 

selected hydrologic, water-quality, and meteorological parameters and relays the information to water managers through 

telephone voice modems and through the USGS Massachusetts-Rhode Island Water Science Center on the World Wide 

Web (http://ma.water.usgs.gov).

Hydrologic Data

Basic data collected at the monitoring stations include 

records of stream stage and measurements of discharge of 

streams, and water altitude and capacity of reservoirs. In 

addition, observations of factors affecting the stage-discharge

relation or the altitude-capacity relation, weather records, 

and other information are used to supplement the basic data 

in determining the daily flow or capacity of water in storage. 

Measurements of discharge are made with a current meter or 

acoustic Doppler current profiler by standard USGS methods 

(Buchanan and Somers, 1968, 1969; Carter and Davidian, 

1968; Kennedy, 1983 and 1984; Oberg and others, 2005; 

Rantz and others, 1982). The methods are consistent with the 

American Society for Testing and Materials (ASTM) standards and generally follow the standards of the International 

Organization for Standards (ISO).

To determine streamflow at each USGS monitoring 

station in the CWD drinking-water source area, dischargerating tables for any stage are prepared from stage-discharge 

curves (Rantz and others, 1982). The daily mean discharge

is computed from these stage and rating tables, and then the 

monthly and yearly mean discharges are computed from 

these daily values. If the stage-discharge relation for a station 

is temporarily changed by aquatic growth or debris in the 

control section, the daily mean discharge is computed by the 

shifting-control method (Rantz and others, 1982).

For the USGS monitoring stations on reservoirs in the 

CWD drinking-water source area, capacity tables giving the 

volume for any reservoir water altitude are prepared from 

water altitude-area relation curves defined by surveys (Fugro 

East, Inc., 1996). From the tables, the daily, monthly, or yearly 

changes in volume are computed.

For some stations, recorder or sensor malfunctions can 

cause gaps in the water-stage record or inaccurate readings, 

which cannot be used to compute daily discharge. For periods 

of malfunction, the daily mean discharges are estimated on 

the basis of the recorded range in stage, prior and subsequent 

records, discharge measurements, weather records, and 

comparison with records from other stations in the same or 

nearby basins. Likewise, reservoir volumes may be estimated 

on the basis of operator’s log, prior and subsequent records, 

and other information.

The accuracy of hydrologic data depends primarily on 

(1) the stability of the stage-discharge relation or, if the control 

is unstable, the frequency of discharge measurements, and 

(2) the accuracy of observations of stage, measurements of 

discharge, and interpretations of records. The degree of accuracy of the records is defined in table 3. Different accuracies 

may be attributed to different portions of a streamflow record.

Table 2. Hydrological, water-quality, and meteorological parameters measured at each continuous-monitoring 

station during water year 2005, eastern Massachusetts.

[USGS, U.S. Geological Survey. X, indicates physical parameter was measured]

Physical 

parameter

USGS station number

01104415 01104430 01104433 01104455 01104460 01104475 01104480 422302071083801

Stream water stage X X X X X X X

Reservoir water level X X X

Precipitation X X X

Air temperature X X X

Water temperature X X X X X X X

Specific conductance X X X X X X X

Continuous Data Collection and Computation 5
Water-Quality Data

Water temperature and specific conductance data 

were collected from continuous water-quality monitors in 

each stream, tributary, or reservoir except for USGS station 

01104480. The accuracy of the water-quality records depends 

primarily on the rate of sensor drift, sensor fouling, and debris 

collection. Typically, sensors became fouled by aquatic growth 

more rapidly in the warmer months. In most cases, corrections 

for fouling and drift can be applied to the data to improve their 

accuracy (Wagner and others, 2003). For parameters other than 

water temperature, such corrections were made on the basis of 

the performance of the sensor before and after sensor maintenance and by noting the response of the clean sensor after 

placing it in several standardized solutions. The accuracy of 

water temperature data is determined by comparing measurements made by the monitoring system and by an independent 

probe calibrated against a National Institute of Standards and 

Technology (NIST) traceable thermometer. One of four 

accuracy classifications ranging from excellent to poor is 

applied to physical properties measured at each station. The 

accuracy rating is based on data values recorded before any 

shifts or corrections are made for fouling and drift. The basis 

for each rating classification is listed in table 3.

Meteorological Data

Precipitation data were collected with heated tippingbucket precipitation gages that measure the volume of rain 

or melted snow in 0.01-inch increments. The precipitation 

gages at the Cambridge Reservoir and Stony Brook Reservoir 

include wind screens that reduce bias generated by precipitation missing the instrument. Precipitation data are summed for 

each day and then for each month. In general, the accuracy of 

precipitation data is assured by proper maintenance and calibration of the device. Precipitation measurements, especially 

when the precipitation is in the form of snow are affected by 

strong winds and are subject to errors. These errors generally 

result in underestimating the total precipitation at a station.

Air temperature data were collected with thermistors 

housed in gill radiation shields. The probes are installed 

approximately 8 feet above ground surface. The maximum, 

minimum, and mean temperature values are computed for 

each day. Monthly statistics are then computed from daily 

values. The accuracy of air temperature data is determined 

by comparing measurements made by the monitoring system 

and by an independent probe calibrated against a NIST-traceable thermometer.

Under rare circumstances, when there were no records of 

precipitation or air temperature, daily values were estimated 

on the basis of records from nearby stations. These circumstances may include a recorder malfunction, the plugging of 

the precipitation gage, or a malfunction of the heating element 

in the precipitation gage.

Sample Collection and Analysis

Water samples were collected during base flow in four 

tributaries in the Cambridge Reservoir and Stony Brook 

Reservoir basins in December 2004 and August 2005. Water 

samples were collected during storms in the same four tributaries in July, August, and September 2005. A sample of raw 

and finished water also was collected in July at the Cambridge 

water treatment plant. Most samples were analyzed for physical, chemical, and biological constituents.

Water samples were collected during base-flow conditions and during rain storms from four tributaries near USGS 

monitoring stations 01104415, 01104433, 01104455, and 

01104475 and analyzed for distributions of particle size

and concentrations of suspended sediment, 6 major dissolved ions, total nitrogen, total phosphorus, 8 total metals, 

18 polyaromatic hydrocarbons (PAHs), 61 pesticides and 

metabolites, and Escherichia coli bacteria. Samples of stream 

water were collected manually (Wilde, and others, 1999) 

under base-flow conditions with an antecedent dry period of 

at least 5 days. During storms, water samples for chemical 

analysis were collected with an automatic sampler controlled 

by a datalogger. The first sample was collected when flow 

exceeded a preset flow threshold, and subsequent samples 

were collected at flow-proportional intervals. Each automatic 

Table 3. Rating classifications for continuous records of 

hydrologic, water quality, and meteorological parameters.

[Modified from Wagner and others, 2003. ≤, less than or equal to; ±, plus or 

minus value shown; °C, degrees Celsius; >, greater than; %, percent; ft, foot]

Measured 

physical 

parameter

Rating

Excellent Good Fair Poor

Discharge ≤ ±5% > ±5 to 10% > ±10 to 15% > ±15%

Reservoir 

altitude

≤ ±0.1 ft > ±0.1 to 0.2 ft > ±0.2 to 0.3 ft > ±0.3 ft

Reservoir 

capacity

≤ ±1% > ±1 to 2% > ±2 to 4% > ±4%

Water 

temperature

≤ ±0.2°C > ±0.2 to 0.5°C > ±0.5 to 0.8°C > ±0.8°C

Specific 

conductance

≤ ±3% > ±3 to 10% > ±10 to 15% > ±15%

Precipitation ≤ ±2% > ±2 to 6% > ±6 to 10% > ±10%

Air 

temperature

≤ ±0.4°C > ±0.4 to 0.8°C > ±0.8 to 2°C > ±2°C

6 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
sampler was configured to hold one 20-liter (L) Teflon-lined 

plastic bottle and fitted with a pre-cleaned 1/2-in. inner diameter Teflon intake tube.

A multi-step process was used to clean all wetted parts 

associated with the automatic sampler and the processing 

equipment before collecting trace inorganic and organic 

constituents. The initial cleaning consisted of washing the 

interior and exterior with a phosphate-free laboratory grade 

soap and tap water, scrubbing surfaces with a plastic brush, 

and rinsing with tap water. Circulating the solution through 

the tubing cleaned the interior of the sampler tubing. Lint-free 

wipes were forced hydraulically through the tubing to remove 

internal deposits or films that were difficult to remove by 

circulating solution alone. After the components dried, they 

were placed in a large stainless steel pan in a fume hood and 

immersed in a 1-to-1 hexane-to-acetone solution. A Teflon 

diaphragm pump was used to circulate the solution through 

the sampler tubing. The components were allowed to soak, 

with occasional agitation, for a period of about 6 hours. After 

appropriately dispensing the waste solution, all components 

except the tubing were rinsed with a 1-to-1 hexane-to-acetone 

solution from a Teflon squeeze bottle and air-dried in a fume 

hood over night. Because the rate of cleaning-solution volatilization was limited within the sampler tubing, the tubing was 

purged with purified air for approximately 20 minutes. The 

final steps involved immersing the components in a 5-percent 

solution of hydrochloric acid for a period of at least 6 hours. 

The same solution was slowly circulated through each sampler 

tube for six hours or more. All components were thoroughly 

rinsed with deionized water until the specific conductance of 

the waste rinse water was less that 1 microsiemens per centimeter (μS/cm).

Samples for chemical analysis were processed in the 

field, usually at the conclusion of each runoff event. Subsamples for the analysis of suspended sediment, and inorganic and 

organic constituents were split directly from the Teflon-lined 

bottle. This method eliminated sample contact with additional 

processing equipment and reduced the potential for contamination. Subsamples were dispensed under low pressure 

directly from the sample bottle with a specialized cap, which 

included a 6.35-millimeter (inner diameter) Teflon dispensing 

tube, a pressure port, and a relief valve. Compressed nitrogen gas applied to the pressure port filled the interior area 

between the bottle wall and the Teflon bag, compressing the 

bag and dispensing the sample. Homogenization of the sample 

was accomplished by fastening the bottle to a cradle assembly capable of rotating 210 degrees. The sample bottle was 

rocked the full 210 degrees several times prior to dispensing, 

and the rocking motion was continued throughout dispensing for all samples except for samples analyzed for dissolved 

constituents. Dissolved constituents were filtered through a 

600-square-centimeter capsule filter with a 0.45-micrometer 

pore size.

Flow-proportional water samples for the analysis of bacteria were collected from a second dedicated automatic sampler. Each automatic sampler was configured to hold between 

one and four 3.75-L glass bottles. Sample lines consisted of 

silicon pump-head tubing and polyethylene intake tubing. The 

sample bottles and pump-head tubing were pre-cleaned and 

sterilized in an autoclave. New polyethylene intake tubing 

was checked for sterility prior to installation, used once, and 

discarded. The sampler base was packed with bagged ice prior 

to each storm. Samples for analysis of bacteria were collected 

automatically at the same frequency as samples collected for 

chemical analysis. Samples for bacteria analysis were processed in the field within 6 hours of the time that the automatic 

sampler was triggered to collect the first sample for each 

bottle. When possible, event mean concentrations (EMCs) of 

Escherichia coli bacteria were mathematically determined by 

calculating the average values for flow-weighted concentrations of sub-composites.

In addition to the environmental samples, water samples 

also were collected for quality assurance. These quality-assurance samples include a source-solution blank, a field blank, 

several processing-equipment blanks, and replicate samples. 

A source-solution blank was prepared from deionized water 

produced by a laboratory-grade water-purification system that 

uses ion-exchange packs and reverse osmosis. The blank water 

was stored in a Teflon-lined bottle until it was subsequently 

used for a field blank. A field blank was collected during 

sample preparation for the July storm. A field blank is used to 

test for positive bias that can result from contamination from 

any stage of the sample collection and processing phase or 

analytical process. The field blank was collected by circulating source water through the automatic sampler tubing and 

bottle, and processed in a manner consistent with the collection of environmental samples of stormwater. Several processing-equipment blanks were collected for bacteria analysis. A 

processing-equipment blank is used to test for positive bias 

that can result from contamination from the ambient environment under which the samples are processed, and from 

contamination of the filters, filter plate, dilution media, agar, 

Petri dishes, and other equipment that may be used for the processing of water samples for bacteria analysis. Finally, several 

replicate-split samples were prepared from samples collected 

during base flow and storms. Replicate-split samples provide 

a measure of variability introduced during sample processing 

and analysis.

Samples were analyzed for concentrations of suspended 

sediment and distribution of particle size at the USGS Kentucky Water Science Center Sediment Lab (Guy, 1970; Sholar 

and Shreve, 1998). Samples were analyzed for chemical 

concentrations at the USGS Laboratory in Denver, Colorado 

(Patton and Kryskalla, 2003; Furlong and others, 2001; American Public Health Association, 1998; Garbarino and Struzeski, 

1998; Hoffman and others, 1996; Fishman, 1993; McLain, 

1993; Fishman and Friedman, 1989; Wershaw and others, 

1987). Samples were processed for bacteria analysis on the 

basis of the methods described by Myers and Sylvester (1997) 

and the U.S. Environmental Protection Agency (USEPA) 

method 1603 (2002b) on site and placed in portable incubators 

in a mobile field laboratory.

Sample Collection and Analysis 7
Presentation of Data

Data collected at the USGS monitoring stations during 

water year 2005 are presented in the back of the report in 

tables 8–16. Where available, each table includes a summary 

of daily values, monthly statistics, annual statistics, gage

datum, and an accuracy rating for each station. The period 

of record and the period-of-record extremes for each physical 

parameter are presented in table 4 by USGS station number. 

The maximum, median, and minimum statistics for selected 

analytical results for the period of record for each USGS 

monitoring station are presented in table 5. Analytical results 

for water samples are presented in the back of the report in 

tables 15 and 16.

Station History

The station history for each USGS station in the Cambridge drinking-water source area is presented in table 4. This 

table includes basic information about the period of record and 

the extremes for the period of record for each physical parameter for current and historical USGS stations in the Cambridge 

drinking-water source area. The “period of record” is the 

time during which each type of data has been collected at the 

station. These data may have been collected manually on an 

intermittent basis or continuously with a monitoring system. 

The “extremes for the period of record” refer to the maximum 

and minimum values measured during the period of record.

Streamflow Data

Streamflow data are presented in table 8. This table 

includes the daily mean values of discharge by USGS station 

number for the 2005 water year, monthly summary statistics, 

annual summary statistics and data pertaining to annual 

runoff and flow duration.

Data Table of Daily Mean Values

The daily table of streamflow records gives the total

discharge for each day of the water year. In the monthly 

summary for the table, the line labeled “Total” gives the sum 

of the daily streamflows for each month; the line labeled 

“Mean” gives the arithmetic average of the daily streamflows 

for the month; the lines labeled “Maximum” and “Minimum” 

give the maximum and minimum daily streamflows 

respectively, for each month; and the line labeled “Median” 

gives the median daily streamflow for each month. Discharge 

per unit area of the drainage basin for the month is expressed 

in millions of gallons per day per square mile (line labeled 

Mgal/d/mi2

); runoff is given in inches (line labeled “Inches”). 

Values for discharge per unit area and runoff in inches are not 

calculated for stations affected by reservoir regulation.

Annual Summary Statistics

Annual summary statistics are presented at the end of 

the water year following the daily mean values and monthly 

summaries. These statistics include the annual total, annual 

mean, annual runoff, and selected streamflow-duration 

percentiles. In the annual summary for the table, the line 

labeled “Annual total” gives the sum of all the daily discharges 

for the water year; the line labeled “Annual mean” gives 

the arithmetic average of the daily discharges for the water 

year. The line labeled “Annual Mgal/d/mi2

” is the average 

number of millions of gallons of water flowing per day from 

each square mile of area drained; the runoff is assumed to 

be distributed uniformly in time and area annually. The line 

labeled “Annual inches” indicates the depth to which the 

drainage area would be covered if all of the runoff for a given 

time period were uniformly distributed on it. Runoff data are 

omitted for stations affected by reservoir regulation. The line 

labeled “10 percent exceeds” indicates the discharge that has 

been exceeded 10 percent of the time for the designated period 

(the 10-percent flow-duration discharge). The lines labeled 

“50 percent exceeds” and “90 percent exceeds” are similarly 

defined. The line labeled “remarks” indicates the accuracy of 

the records (table 2).

Reservoir Data

Continuous records of reservoir altitude and capacity 

for the Cambridge Reservoir, Stony Brook Reservoir, and the 

Fresh Pond Reservoir are presented in tables 9 and 10, respectively. Data tables for each parameter consist of daily mean 

values that include monthly and annual minimum, maximum, 

and mean values, a gage description, and an accuracy rating 

description. The line labeled “Gage” indicates the value and 

source of the datum used to monitor reservoir altitudes. The 

line labeled “Remarks” indicates the accuracy of the records 

(table 2). The accuracy of reservoir capacity is determined 

on the basis of the average annual altitude for each reservoir 

and the difference in capacity associated with the error in the 

measurements of the reservoir altitude.

Meteorological and Water-Quality Data

Continuous records of meteorological and water-quality parameters are presented in tables 11 through 14. Data 

tables for precipitation consist of daily totals that also include 

monthly and annual totals and maximum values, and an accuracy rating description. Data tables for all other parameters 

consist of daily maximum, minimum, and mean values that 

also include monthly and annual minimum, maximum, and 

mean values, and an accuracy rating description.

8 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Water-Quality Data

Analytical results for water samples, including concentrations of Escherichia coli bacteria in samples of water collected 

during base-flow conditions and estimated concentrations of 

Escherichia coli bacteria for composites of stormwater are 

presented in table 15. Analytical results for concentrations of 

Escherichia coli bacteria for all samples are presented in 

table 16. Quality-control samples are listed at bottom of each 

table. The maximum, median, and minimum statistics for 

concentrations of selected constituents in water samples collected during the period of record for each USGS station in the 

Cambridge drinking-water source area are presented in table 5.

Data for the Cambridge Drinking-Water 

Source Area

The data presented in this report can be used by the 

water-resource managers in the city of Cambridge, Massachusetts, to optimize the management of the drinking-water-supply reservoirs for water quality and quantity. The data allow 

clarification of the relation between reservoir management 

practices and current conditions, and trends in water quantity 

and quality in the subbasins of the hydrologic system.

Surface-Water Data

From October 2004 through May 2005, water from 

the Hobbs Brook Basin accounted for about 8 to 40 percent 

(estimated by dividing the sum of monthly discharges 

measured at USGS stations 01104430 and 01104433 

by the sum of monthly discharges measured at USGS 

stations 01104460 and 01104475) of the water entering 

the downstream Stony Brook Reservoir (fig. 2). During 

the remainder of the water year (June through September), 

the amount of water from the Hobbs Brook Basin, most of 

which was released from the Cambridge Reservoir, steadily 

increased to about 99 percent of the total inflow of the Stony 

Brook Reservoir despite somewhat uniform rainfall during 

the summer. From December 2004 through May 2005, about 

70 percent of all water entering the Stony Brook Reservoir 

(estimated by dividing the sum of monthly reservoir outflows 

measured at USGS station 01104480 by the sum of monthly 

discharges measured at USGS stations 01104460 and 

01104475) was diverted to the Charles River (fig. 2). The 

volume of water released from the Stony Brook Reservoir to 

the Charles River during water year 2005 represents an annual 

surplus of about 119 percent of the total annual water demand 

by the city of Cambridge. During the past 5 years, this surplus 

has ranged from 29 to 155 percent assuming an average 

demand of 15 Mgal/d.

Monthly reservoir capacities for the Cambridge 

Reservoir varied from about 59 to 98 percent during water 

year 2005 (fig. 3). The reservoir was near capacity in the 

spring, but was subsequently drawn down as additional 

water was needed to supplement the city of Cambridge water 

demand when the yield from the Stony Brook basin diminished. Monthly reservoir capacities for the Stony Brook Reservoir and the Fresh Pond Reservoir were maintained at capacities greater than 84 and 96 percent, respectively, during water 

year 2005 (fig. 3). In January 2005, the CWD installed three 

stop logs in the Cambridge Reservoir spillway, consequently 

increasing the spillway altitude by an additional 1.6 feet and 

the reservoir capacity by an estimated 220 millions gallons 

(Mgal) or 8.8 percent.

Water-Quality Data

The monthly mean specific conductances for water 

discharged from the Cambridge Reservoir were equal to or 

within the interquartile range of the monthly mean specific 

conductances for the period of 1997 through 2005 (fig. 4). 

The monthly mean specific conductances for Stony Brook at 

USGS station 01104460 were generally higher than medians 

of the monthly mean specific conductances for the period of 

1997 through 1998 and 2002 through 2004, and for 5 months, 

new maximum monthly mean specific conductances were 

calculated (fig. 5). The annual mean specific conductance for 

Fresh Pond Reservoir increased from 514 μS/cm in the 2004 

water year (Smith, 2005) to 553 μS/cm during the 2005 water 

year (table 14). The running average specific conductance 

for Fresh Pond Reservoir increased by 43 μS/cm or about 

8 percent between July 1 and September 30 (fig. 6) as a result 

of the increasing influx of water from the Cambridge Reservoir, which has a greater specific conductance, compared to 

water from the principal stream in the Stony Brook Basin.

Many of the small tributaries to the reservoirs differ from 

the principal streams in that the water quantity, as well as 

the water quality of the tributaries, responds more rapidly to 

stormwater runoff. Data illustrating these effects for flow and 

specific conductance at USGS station 01104415 are shown 

in figure 7. The daily mean specific conductance values for 

USGS stations 01104415, 01104433, and 01104455 differed 

by as much as 661 percent relative to the annual mean values 

during water year 2005. Daily mean specific conductance values for USGS station 01104475 differed by about 155 μS/cm 

or about 55 percent of the mean annual value during water 

year 2005. The coefficient of variation (COV) for monthly 

mean specific conductance values ranged from about 8 percent 

to about 35 percent (01104475>01104415>01104433>01104

455). On the basis of 7 years of continuous specific conductance measurements at USGS station 01104455 (Smith, 2005; 

Socolow and others, 1999, 2000, 2001, 2002, 2003, and 2004), 

new maximum monthly mean values were established for 

7 months during water year 2005 (fig. 8).

Data for the Cambridge Drinking-Water Source Area 9
Table 4. Extreme measurements of physical parameters for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts. Unless otherwise 

footnoted, measurements of physical parameters were made both manually on an intermittent basis and automatically on a continuous basis.—Continued[POR, period of record; yr, year; Mgal/d, millions of gallons per day; ft, feet above City of Cambridge datum; Mgal, millions of gallons; in/15min, inches of precipitation within a 15-minute interval; °C, degree Celsius; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μS/cm, microsiemen per centimeter at 25° Celsius; (XX), value of parameter measured during water year 2005; —, no data]

Constituent Statistic USGS station number 01104390 01104405 01104410 01104415 01104420 01104430 01104433 01104440 01104455 01104460 01104475 01104480 422302071083801

Discharge 

(Mgal/d)

POR 03/07/97– 09/17/981 03/05/97– 09/30/98 03/05/97– 09/30/98

03/06/97–

09/30/98; 

08/26/04–

current yr

04/09/97– 

09/30/98

03/06/97– 

current yr

10/23/97–

09/17/981; 

06/28/04– 

current yr

03/07/97– 

09/30/98

10/22/97–

09/22/98; 

10/01/00–

current yr

03/07/97–

10/28/98; 

05/14/02–

current yr

11/06/97–

09/17/981; 

12/24/03–

current yr

10/01/99– 

current yr

—

Maximum 37 102 22 91 (50) 47 40 (40) 6.4 (3.4) 61 77 (55) 277 (183) 10.8 (7.1) 420 (420)

—

Minimum .51 .00 .00 .00 (.00) .05 .00 (.23) .00 (.00) 1.0 .08 (.08) 2.2 (5.62) .05 (.05) .00 (.06)

—

Reservoir 

altitude (ft)

POR

—

—

—

—

— 10/01/01 – 

current yr

—

—

—

—

— 10/01/99– 

current yr

10/01/03– 

current yr

Maximum

—

—

—

—

— 182.81 

(182.81)

—

—

—

—

— 81.73 

(81.02)

16.75 

(16.75)

Minimum

—

—

—

—

— 169.78 

(174.56)

—

—

—

—

— 62.60 

(74.56)

15.29 

(15.38)

Reservoir 

capacity (Mgal)

POR

—

—

—

—

— 10/01/01– 

current yr

—

—

—

—

— 10/01/99– 

current yr

10/01/03 – 

current yr

Maximum

—

—

—

—

— 2,711 

(2,711)

—

—

—

—

— 271 

(265)

1537 

(1537)

Minimum

—

—

—

—

— 758 (1,382)

—

—

—

—

— 29.5 (199) 1463 (1467)

Precipitation (in/

15min)

POR

—

—

—

—

— 10/01/01– 

current yr

—

—

—

—

— 11/01/01– 

current yr

06/08/04– 

current yr

Maximum

—

—

—

—

— .72 (.68)

—

—

—

—

— .57 (.49) .91 (.91)

Minimum

—

—

—

—

—

—

—

—

—

—

—

—

—

Air temperature 

(°C)

POR

—

—

—

—

— 10/01/01– 

current yr

—

—

—

—

— 11/01/01 – 

current yr

10/01/03– 

current yr

Maximum

—

—

—

—

— 35.2 (33.6)

—

—

—

—

— 36.5 (34.1) 35.4 (35.4)

Minimum

—

—

—

—

— –23.1 

(–21.0)

—

—

—

—

— –22.2 

(–20.4)

–22 

(–19.1)

Water temperature 

(°C)

POR 03/07/97 – 

09/17/981

03/05/97– 

09/30/98

03/05/97– 

09/30/98

03/06/97–

09/30/98; 

08/26/04–

current yr

04/09/97– 

09/30/98

03/06/97– 

current yr

10/23/97–

09/17/981; 

06/28/04–

current yr

03/07/97– 

10/28/98

10/22/97 –

09/22/98; 

10/01/00 –

current yr

03/07/97 –

10/28/98; 

05/14/02 –

current yr

11/06/97–

9/17/981; 

12/24/03–

current yr

11/01/01 – 

04/30/02

10/01/03– 

current yr

Maximum 30.6 22.7 25.1 25.5 (25.5) 26.3 26.5 (26.2) 27.6 (27.6) 24.1 27.1 (27.0) 26.7 (24.7) 23.5 (23.5) 19.2 28.5 (28.5)

Minimum –1.0 –.4 –.2 –.8 (–.7) –.3 .2 (.8) –.5 (–.5) .0 .1 (1.1) –0.1 (–.1) –.1 (.2) 2.5 –.4 (.4)

10 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 4. Extreme measurements of physical parameters for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts. Unless otherwise 

footnoted, measurements of physical parameters were made both manually on an intermittent basis and automatically on a continuous basis.—Continued[POR, period of record; yr, year; Mgal/d, millions of gallons per day; ft, feet above City of Cambridge datum; Mgal, millions of gallons; in/15min, inches of precipitation within a 15-minute interval; °C, degree Celsius; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μS/cm, microsiemen per centimeter at 25° Celsius; (XX), value of parameter measured during water year 2005; —, no data]

Constituent Statistic USGS station number 01104390 01104405 01104410 01104415 01104420 01104430 01104433 01104440 01104455 01104460 01104475 01104480 422302071083801

Specific 

conductance (μs/cm)

POR 03/07/97– 

09/17/981

03/05/97– 

09/30/98

03/05/97– 

09/30/98

03/06/97–

09/30/98; 

08/26/04–

current yr

04/09/97– 

09/30/98

03/06/97– 

current yr

10/23/97–

09/17/981; 

06/28/04–

current yr

04/09/97 –

10/28/98

10/22/97 –

09/22/98; 

10/01/00 –

current yr

03/07/97–

10/28/98; 

05/14/02–

current yr

11/06/97–

09/17/981; 

12/24/03–

current yr

11/01/01– 

11/05/03

10/01/03– 

current yr

Maximum 250 4,360 1,430 26,800

(16,800)

7,500 1,940 

(926)

10,300

(10,300)

1,170 72,700

(22,300)

3,420

(1,770)

3,540 

(778)

865 770 

(760)

Minimum 112 39 54 42 

(210)

18 163 

(585)

52 

(52)

128 13

(28)

45 

(218)

40 

(61)

308 452 

(464)

Dissolved oxygen (mg/L)

POR 10/22/97– 

09/17/981

10/27/97– 09/16/981

10/27/97 – 09/16/981

04/07/97–09/16/981; 08/26/04–current yr1

10/22/97 – 09/16/981

10/21/97– 09/16/981

10/23/97–09/17/981; 08/27/04–

current yr1

10/21/97– 10/28/981

10/22/97 –09/22/98; 08/27/04 –

current yr

10/22/97–

10/28/981; 

05/14/02–

current yr1

11/06/97–

09/17/981; 

08/26/04–

current yr1

11/01/01–

11/05/03

—

Maximum 13.6 15 11.6 11.6 (11.4) 13.3 14.7 11.8 (8.9) 14.0 12.8 (9.7) 13.4 14.6 (12.3) 13.7 —

Minimum 7.0 6.1 7.2 5.3 (5.3) 5.5 7.3 .9 (4.2) 7.7 7.6 (6.7) 7.4 7.4 (7.4) 2.8 —

pH POR 03/07/97–

09/17/981

03/05/97–09/16/981

10/27/97–09/16/981

03/06/97–09/16/981; 08/26/04–current yr1

04/09/97–09/16/981

03/06/97–09/16/981

10/23/97–09/17/981; 08/27/04–

current yr1

03/07/97–10/28/981

10/22/97–09/22/98; 08/27/04–

current yr

03/07/97–

10/28/98; 

05/14/02–

current yr

11/06/97–

09/17/981; 

08/26/04–

current yr1

11/01/01–

10/31/03

—

Maximum 7.8 7.9 7.2 7.2 (6.8) 8.7 7.5 7.7 (7.0) 7.6 7.7 (6.7) 7.0 7.5 (7.3) 7.5 —Minimum 6.2 5.8 5.5 6.1 (6.1) 4.1 5.8 5.9 (6.5) 6.0 6.1 (6.1) 6.0 6.3 (6.6) 6.5 —

Turbidity (NTRU)

POR — — — 08/26/04– 

current yr1

— 06/12/02 

–09/04/021

08/27/04–

current 

yr1

— 10/22/97–

09/22/981; 

08/27/04–

current yr1

06/13/02–

current yr

08/26/04–

current 

yr1

11/01/01–

11/05/03

—

Maximum — — — 79 (79) — 3.0 1.8 (1.8) — 120 (70) 2270 150 (150) 3 97 —

Minimum — — — 1.1 (1.1) — .4 45 (45) — .4 (.6) 2.6 .6 (.6) 3.3 —

1Measurements of physical parameters were made manually and on an intermittent basis.2Turbidity values are expressed in formazin nephelometric multibeam units.3Turbidity values are expressed in formazin nephelometric units.

Data for the Cambridge Drinking-Water Source Area 11
Table 5. Extreme and median constituent concentrations measured in water samples for U.S. Geological Survey monitoring stations in the drinking-water source area 

for Cambridge, Massachusetts, for the period of record.—Continued

[POR, period of record; N, number of samples; mg/L, milligram per liter; yr, year; <, less than]

Constituent Statistic

USGS station number

01104390 01104405 01104410 01104415 01104420 01104430 01104433 01104440 01104455 01104460 01104475

Calcium 

(mg/L) (filtered)

POR 03/07/97–

09/17/98

03/05/97–

 09/16/98

03/05/97–

 09/16/98

03/06/97–

09/16/98; 

08/26/04–

current yr

04/09/97–

 09/16/98

03/06/97–

 10/27/98

10/23/97–

 09/15/05

03/07/97–

 10/28/98

10/22/97–

09/22/98; 

03/05/03–

current yr

03/07/97–

 10/28/98

12/17/97–

09/17/98; 

08/26/04–

current yr

Maximum 20 35 62 340 88 21.9 85.7 21.5 70.4 21.2 21.3Medium 13 13 29.5 47.6 33 17.9 52 17.5 30.5 16.6 12.9Minimum 10 8.2 15 10.8 13 15.8 26 16 5.3 12.3 7.69N 25 28 24 40 32 26 14 26 22 28 19

Sodium 

(mg/L) (filtered)

POR 03/07/97–

09/17/98

03/05/97–

09/16/98

03/05/97–

 09/16/98

03/06/97–

09/16/98; 

08/26/04–

current yr

04/09/97–

09/16/98

03/06/97–

10/27/98

10/23/97–

09/15/05

03/07/97–

 10/28/98

10/22/97–

09/22/98; 

03/05/03–

current yr

03/07/97–

 10/28/98

12/17/97–

09/17/98; 

08/26/04–

current yr

Maximum 25 382 251 5220 936 88.9 281 76.1 3,600 67.8 33.9

Median 15 27.5 104.5 253 111 64 165 61.35 97 39.8 18.2

Minimum 12 18 71 59.6 50 56.3 67 37.9 18 23.5 14

N 25 28 24 40 32 26 14 26 22 28 19

Chloride 

(mg/L) (filtered)

POR 03/07/97– 

09/17/98

03/05/97–

 09/16/98

03/05/97–

 09/16/98

03/06/97–

09/16/98; 

08/26/04–

current yr

04/09/97–

 09/16/98

03/06/97–

 10/27/98

10/23/97–

 09/15/05

03/07/97–

 10/28/98

10/22/97–

09/22/98; 

03/05/03–

current yr

03/07/97–

 10/28/98

12/17/97–

09/17/98; 

08/26/04–

current yr

Maximum 45 680 490 9,000 1,600 162 544 136 5,800 122 66.8

Median 26 44.5 210 460 210 115 330 107.5 165 70 28

Minimum 20 37 120 110 81 105 110 69.9 20 36.7 21N 25 28 24 40 32 26 14 26 22 28 19

12 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 5. Extreme and median constituent concentrations measured in water samples for U.S. Geological Survey monitoring stations in the drinking-water source area 

for Cambridge, Massachusetts, for the period of record.—Continued

[POR, period of record; N, number of samples; mg/L, milligram per liter; yr, year; <, less than]

Constituent Statistic

USGS station number

01104390 01104405 01104410 01104415 01104420 01104430 01104433 01104440 01104455 01104460 01104475

Sulfate 

(mg/L) (filtered)

POR 04/09/97– 

09/17/98

04/07/97– 

09/16/98

04/07/97–

 09/16/98

04/07/97–

09/16/98; 

08/26/04–

current yr

04/09/97– 

09/16/98

04/09/97–

10/27/98

10/23/97– 

09/15/05

04/09/97– 

10/28/98

10/22/97–

09/22/98; 

03/05/03–

current yr

04/15/97– 

10/28/98

11/20/97–

09/17/98; 

08/26/04–

current yr

Maximum 21 39 24 180 38 18.8 34.9 18.6 85 18.7 24

Median 13 15 12 28 21 14.1 27.6 13.4 25 13.1 16

Minimum 7.4 6.8 7.5 6.2 5.2 9.5 16 9.5 4.8 10.5 8

N 13 17 12 29 21 14 14 14 20 15 21

Phosphorus 

(mg/L)(unfiltered)

POR 04/09/97–

09/17/98

04/07/97–

 09/16/98

04/07/97–

09/16/98

04/07/97–

09/16/98; 

08/26/04–

current yr

04/09/97–

09/16/98

04/09/97–

10/27/98

10/23/97–

 09/15/05

04/09/97–

10/28/98

10/22/97–

09/22/98; 

03/05/03–

current year

04/15/97–

10/28/98

11/20/97–

09/17/98; 

08/26/04–

current yr

Maximum 0.02 0.05 0.18 0.5 0.07 0.03 0.18 0.06 0.45 0.06 0.8

Median <.01 .02 <.01 <.01 <.01 <.01 .02 .01 <.01 <.01 .02Minimum <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01

N 13 19 14 27 20 16 16 15 22 17 21

Nitrogen, 

(mg/L)(total)

POR 04/09/97–

09/17/98

04/07/97–

09/16/98

04/07/97–

09/16/98

04/07/97–

09/16/98; 

08/26/04–

current yr

04/09/97–

09/16/98

04/09/97–

10/27/98

10/23/97–

09/15/05

04/09/97–

10/28/98

10/22/97–

09/22/98; 

03/05/03–

current yr

04/15/97–10/28/98

11/20/97–

09/17/98; 

08/26/04–

current yr

Maximum 1.3 1.04 .87 2.38 1.34 .53 2.64 1.27 4.23 1.03 5.13

Median .93 .64 .50 1.59 .99 .42 1.72 .57 1.79 .7 1.28

Minimum .65 .45 .33 .82 .37 .24 .59 .13 .62 .17 .84

N 14 19 14 28 20 15 16 15 22 17 21

Data for the Cambridge Drinking-Water Source Area 13
Figure 2. The percentage of water supplied from the Hobbs Brook basin relative to the total water entering the 

Stony Brook Reservoir compared to the percentage of water discharged from the Stony Brook Reservoir to the 

Charles River relative to the total inflow for water year 2005, eastern Massachusetts.

Figure 3. Monthly mean reservoir-storage capacities for water year 2005 shown as percent capacity for the 

Cambridge Reservoir, Stony Brook Reservoir, and Fresh Pond Reservoir, eastern Massachusetts.

0

10

20

30

40

50

60

70

80

90

100

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

WATER YEAR 2005

PERCENT

Discharge from Hobbs Brook Basin

Water surplus from Stony Brook Reservoir

EXPLANATION

50

60

70

80

90

100

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

WATER YEAR 2005

CAPACITY, IN PERCENT

Fresh Pond Reservoir

Stony Brook Reservoir

Cambridge Reservoir

14 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Figure 4. Monthly mean specific conductance for water year 2005 for USGS station 01104430, Hobbs Brook below Cambridge 

Reservoir near Kendal Green, Massachusetts, compared to the period-of-record maximum and minimum monthly mean specific 

conductance, and the median monthly specific conductance for water years 1997–2004.

0

400

800

1,200

1,600

SPECIFIC CONDUCTANCE, IN MICROSIEMENS

PER CENTIMETER

Monthly mean specific conductance for 2005 water year

Median monthly specific conductance for period 1997–2004

Unshaded area shows range between the 25th percentile and the

 75th percentile. Lightly shaded area shows the range between

 the 75th percentile and the highest monthly mean value and the

 25th percentile and the lowest monthly mean value for the period

 of station record

EXPLANATION

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

WATER YEAR

Data for the Cambridge Drinking-Water Source Area 15
Figure 5. Monthly mean specific conductance for water year 2005 for USGS station 01104460, Stony Brook at Route 20 at 

Waltham, Massachusetts, compared to the period-of-record maximum and minimum monthly mean specific conductance, and 

the median monthly specific conductance for water years 1997–1998 and 2002–2004.

300

400

200

500

600

800

700

SPECIFIC CONDUCTANCE, IN MICROSIEMENS

PER CENTIMETER

Monthly mean specific conductance for 2005 water year

Median monthly specific conductance for period 1997–1998

 and 2002–2004

Unshaded area shows range between the highest and lowest

 monthly mean value for period-of-station record

EXPLANATION

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

WATER YEAR

16 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Figure 6. Daily mean specific-conductance values for USGS station 422302071083801, Fresh Pond Reservoir at Cambridge, 

Massachusetts, for water year 2005.

OCT. NOV. DEC.

2004 2005

JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

400

450

500

550

600

650

700

750

800

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

Data for the Cambridge Drinking-Water Source Area 17
Figure 7. (A) Daily total flows greater than 0.01 million gallons per day, and (B) daily maximum and daily minimum specific 

conductance values for USGS station 01104415, Cambridge Reservoir, unnamed tributary 2, near Lexington, Massachusetts, for 

water year 2005.

0.01

0.04

0.1

0.4

1

4

8

OCT. NOV. DEC.

2004 2005

JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

Maximum daily specific conductance

Minimum daily specific conductance

SPECIFIC CONDUCTANCE, IN MICROSIEMENS

PER CENTIMETER

DISCHARGE, IN MILLIONS OF GALLONS

PER DAY

A

B

18 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Figure 8. Monthly mean specific conductance for water year 2005 for USGS station 01104455, Stony Brook, unnamed tributary 1, 

near Waltham, Massachusetts, compared to the period-of-record maximum and minimum monthly mean specific conductance, 

and the median monthly specific conductance for water years 1998–2004.

Monthly mean specific conductance for 2005 water year

Median monthly specific conductance for period 1998–2004

Unshaded area shows range between the 25th percentile and the

 75th percentile. Lightly shaded area shows the range between

 the 75th percentile and the highest monthly mean value and the

 25th percentile and the lowest monthly mean value for the period

 of station record

EXPLANATION

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

8,000

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

9,000

SPECIFIC CONDUCTANCE, IN MICROSIEMENS

PER CENTIMETER

WATER YEAR

Data for the Cambridge Drinking-Water Source Area 19
Water Samples

Concentrations of most dissolved constituents in water 

samples collected during storms were generally lower than 

the concentrations observed in water samples collected during 

base-flow conditions. Nutrient concentrations, including total 

nitrogen and total phosphorus were similar in samples collected during base-flow conditions for all subbasins; however, 

phosphorus concentrations were substantially greater in stormwater samples. Most total-recoverable metals were detected 

in samples of base-flow water as well as in samples of stormwater. Detections of chromium were observed only in samples 

of stormwater except for one sample collected under base-flow 

conditions at USGS station 01104415. Lead concentrations 

were consistently higher in samples of stormwater. With the 

exception of cadmium and manganese, concentrations of 

total metals and suspended sediment were generally higher in 

samples of stormwater than in samples of base-flow water for 

each of the tributaries.

Iron, manganese, nickel, and zinc were the only metals 

detected in the field-blank water. Concentrations of iron, manganese, and nickel were at least about an order of magnitude 

less than the lowest concentration found in the environmental 

samples collected at the four tributaries. Although the concentration of zinc measured in the field-blank water was low, the 

results for several environmental samples (particularly those 

samples collected at USGS station 01104475) also were low 

and should be viewed with caution. Assuming the concentration of zinc measured in the field-blank water represents 

the maximum amount of contamination present in any given 

sample, the potential bias is within the measurement error of 

the analytical technique (Garbarino and Struzeski, 1998) for 

environmental samples with concentrations of zinc greater 

than 20 micrograms per liter (μg/L).

Concentrations of dissolved chloride and total recoverable manganese in samples of base-flow water collected at 

USGS stations 01104415, 01104433, and 01104455 during 

December and August exceeded the USEPA secondary drinking water standards of 250 and 0.05 mg/L (U.S. Environmental Protection Agency, 2002a), respectively. In samples of 

stormwater collected at USGS stations 01104415, 01104433, 

01104455, and 01104475 in July, August, and September, 

concentrations of dissolved chloride were below the secondary standard. Conversely, concentrations of total recoverable 

manganese in all samples of stormwater exceeded the secondary drinking water standard. In half of the water samples collected at USGS stations 01104415, 01104455 and 01104475, 

concentrations of total recoverable iron exceeded the USEPA 

secondary drinking water standard of 0.3 mg/L (U.S. Environmental Protection Agency, 2002a). Concentrations of total 

recoverable iron in all four samples collected at USGS station 

01104433 exceeded the secondary standard. In several cases, 

the concentrations of total recoverable iron in water samples 

collected during storms exceeded the standard by more than an 

order of magnitude.

National secondary drinking water regulations are 

non-mandatory water-quality standards established by the 

USEPA. They are guidelines designed to assist public water 

suppliers in managing their drinking water for aesthetic 

considerations, such as taste, odor, color, foaming, corrosivity, staining, scaling, and sedimentation. These constituents do 

not present a risk to human health at the secondary maximum 

contaminant level (U.S. Environmental Protection Agency, 

2002a). Although these standards are typically applied to 

finished water, the presence of these constituents in concentrations that exceed the respective standards can damage water 

equipment or reduce the effectiveness of treatment for other 

contaminants. Some constituents, such as chloride, sodium, 

and nitrogen, cannot be effectively removed or reduced during 

the water treatment process (table 15).

Concentrations of Escherichia coli bacteria in water samples of base flow ranged from 4 to 1,400 colony-forming units 

per 100 mL (col/100mL). Bacterial concentrations were lower 

in water samples of base flow collected in December compared to water samples of base flow collected in July. Concentrations of Escherichia coli bacteria in composite samples 

of stormwater ranged between 1,700 to 43,000 col/100mL) 

with the highest concentrations measured at USGS station 

01104475. Bacteria concentrations in all equipment-blank 

samples were less than the detection limit. The difference 

between concentrations of bacteria in replicate split samples 

ranged from 5 to 91 percent.

Fluoranthene, 9H-fluorene, acenaphthene, anthracene, 

phenanthrene, and pyrene were the only PAHs detected in 

samples of base-flow water. Fluoranthene and pyrene were the 

most commonly detected compounds in base-flow samples. 

Concentrations of PAH compounds observed in composite 

samples of stormwater were higher, often as much as an 

order of magnitude or more, than concentrations measured in 

samples of base-flow water. With the exception of nitrobenzene, which was the only compound not detected at a concentration of 2 μg/L in any sample, all PAH compounds were 

detected at all subbasins in one or both composite samples 

of stormwater. Fluoranthene, phenanthrene, and pyrene were 

the only PAH compounds found in the water sample collected 

from the Fresh Pond Reservoir intake structure. None of these 

compounds were detected at the respective detection limits 

(table 15) in the finished drinking water.

Naphthalene was the only PAH compound detected in the 

field blank. The field blank concentration was about 2 times 

greater than the environmental sample concentrations, and 

as a result, the environmental results should be viewed with 

caution. One possible explanation for the detection of naphthalene in the field blank is that sodium naphthalene is used in 

the manufacturing of some Teflon products (Benderly, 1962). 

Because the source water was stored in a bottle lined with a 

Teflon bag for nearly 14 months, it is possible that the naphthalene leached from the bag and therefore the concentrations 

found in the environmental samples may be in fact valid.

Sixteen pesticides and caffeine were detected in water 

samples collected in four tributaries and in raw water collected 

20 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Data for the Cambridge Drinking-Water Source Area 21

from the Cambridge water-treatment facility intake from 

the Fresh Pond Reservoir in water year 2005. Most of these 

pesticides are found in over-the-counter products used for 

turf management and the treatment of ornamental shrubs 

(table 6). Caffeine, 2,4-D, imidacloprid, and siduron were 

the only compounds detected in all four subbasins. Carbaryl 

and metsulfuron were detected in three of the four subbasins. 

Caffeine, imidacloprid, and siduron were also detected 

in water from the Fresh Pond Reservoir. The compounds 

3-ketocarbofuran, carbaryl, MCPA, propoxur, siduron, and 

triclopyr were only detected in water samples collected from 

storm-water runoff. Caffeine, imidacloprid, and siduron were 

the most frequently detected compounds (table 7).

Meteorological Data

The distribution of monthly precipitation totals for the 

USGS station at the Cambridge Reservoir (fig. 9) was more 

uniform during the 2005 water year than during any other 

water year for the period of record (Smith, 2005; Socolow and 

others, 2002, 2003, and 2004). The COVs for monthly precipitation totals for the three stations that measured precipitation 

ranged from about 32 to 34 percent. Monthly precipitation 

totals for USGS stations at the Stony Brook Reservoir and the 

Fresh Pond Reservoir differed by -10 to 47 percent compared 

to the USGS station at the Cambridge Reservoir. Average 

differences compared to the station at the Cambridge Reservoir were about 19 and 26 percent, respectively. In general, 

variability between monthly precipitation totals for all stations 

is attributed to differences in storm tracks, storm intensity 

patterns, and storm wind intensity. Additionally, variability 

between monthly precipitation totals during the winter months 

is compounded by a change in precipitation type, that is, snow 

is less dense and therefore affected more by wind. The precipitation gages at the Stony Brook Reservoir and Fresh Pond 

Reservoir are more susceptible to wind bias and therefore the 

totals are generally lower (fig. 9). The annual precipitation 

total recorded at the Cambridge Reservoir during water year 

2005 was within 2 inches of the totals recorded during the 

previous two water years.

Mean monthly air temperature values were similar from 

site to site, differing by no more than about 1.5o

C. Mean 

monthly air temperature values for the USGS station at the 

Cambridge Reservoir had the greatest amount of variability in 

the months of January and February (fig. 10). During the 2005 

water year, mean monthly air temperature values were within 

1o

C of the median values for water years 2002 through 2004, 

except for the months of January, March, May, and June.
22 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005 Table 6. Characteristics of selected pesticides detected in base-flow and stormflow water samples collected in the Hobbs Brook and Stony Brook Reservoir basins, eastern Massachusetts, for water year 2005.—Continued [CAS, Chemical Abstracts Service] Pesticide target analyte Trade or common names Type of pesticide CAS registry number Use References Caffeine None Stimulant 58-08-2 Coffee, tea, cocoa, soft drinks, chocolate, prescription, and over-the-counter drugs. Seiler, R.L. and others (1999) 2,4-D “Agent White,” Bladex-B, Brush Killer 64, Dicofur, Dormon, Ipaner, Moxon, Netagrone, Pielik, Verton 38, Mota Maskros, Silvaprop 1, Agricorn D, Acme LV4, Croprider, Fern- esta, Lawn-Keep, Pennamine D, Plantgard, Tributon, Weed-B-Gon®, Weedatul, Agrox- one, Weedar®, Salvo, Green Cross Weed- No-More 80, Red Devil Dry Weed Killer, Scott’s 4XD, Weed-Rhap LV40, Weedone 100, 2,4-Dichloro-phenoxyacetic acid, and Weedon-2,4,-DP Herbicide 94-74-7 Used for the control of broad-leaf weeds in agriculture, and for control of woody plants along roadsides, railways, and utilities rights of way. U.S. Environmental Protection Agency (2006a), Wagner and others (2006) 2-Chloro- 6-ethylamino- 4-amino- s-triazine Metabolite of atrazine Herbicide metabolite 94-75-7 Parent compound is used to control broadleaf and grassy weeds in crops and non-cropped areas. Wagner and others (2006) 3-Ketocarbofuran Metabolite of carbofuran Insecticide metabolite 16709-30-1 Parent compound is used to control beetles, nematodes and rootworm. Applications include alfalfa, rice, grapes, and turf. U.S. Environmental Protection Agency (2006b) Benomyl Benlate, Tersan Fungicide 17804-35-2 Used as a fungicide on vegetables, ornament shrubs, and turf. U.S. Environmental Protection Agency (2001), Hornsby and others (1996) Carbaryl Ortho Seven, Sevin Insecticide 63-25-2 Used as a broad-spectrum insecticide in agriculture, professional turf manage- ment and ornamental production, and residential lawns and gardens. U.S. Environmental Protection Agency (2004b), Hornsby and others (1996) Diuron Aguton, DCMU, Di-on, Direx, Karmex, Topsite Herbicide 330-54-1 Used to control weeds and mosses on turf and on many crops. Wagner and others (2006), Hornsby and others (1996), Extension Toxicology Network (1993a) Imazaquin Ala-Scept, Scepter, Squadron, Tri-Scept, Partner, Skepter 1.5L, and Image 1.5LC Herbicide 81335-37-7 Selective, pre- and postemergence herbicide. Wagner and others (2006), Exten- sion Toxicology Network (1996), Hornsby and others (1996)
Table 6. Characteristics of selected pesticides detected in base-flow and stormflow water samples collected in the Hobbs Brook and Stony Brook Reservoir basins, 

eastern Massachusetts, for water year 2005.—Continued

[CAS, Chemical Abstracts Service]

Pesticide target 

analyte Trade or common names Type of pesticide CAS registry number Use References

Imidacloprid Admire, Condifor, Gaucho, Premier, 

Premise, Provado, Marathon and Merit

Insecticide 138261-41-3 Used to control sucking insects, including 

aphids, termites, and turf insects in crops and turf.

Wagner and others (2006), Extension Toxicology 

Network (2005)

MCPA Agritox, Agroxone, Border Master, 

Chiptox, Metaxon, Rhomene, Rhonox, Weed-Rhap, Weedone, Weedar

Herbicide 94-74-6 Used for selective control of broadleaf weeds 

on turf, lawns, vines, rights-of-way, and forestry applications.

Wagner and others (2006), U.S. Environmental 

Protection Agency (2004a), Hornsby and others (1996), Extension Toxicology Network (1993b) 

Metalaxyl Ridomil, Apron, Delta-Coat AD, 

Subdue 2E

Fungicide 57837-19-1 Controls plant diseases caused by watermold fungi. Used on crops, ornament 

shrubs and trees, and turf.

Wagner and others (2006), Hornsby and others 

(1996), U.S. Environmental Protection Agency (1994), Extension Toxicology Network (1993c) 

Metsulfuron Escort®, Ally®, Allie, Grooper Herbicide 74223-64-6 Used as a selective pre- and postemergence 

herbicide for broadleaf weeds and some annual grasses.

Wagner and others (2006), Hornsby and others (1996), Extension Toxicology Network 

(1993d) 

Norflurazon Zorial, Solicam, Evital Herbicide 27314-13-2 Used to control germinating annual grasses 

and broadleaf weeds in agricultural, nonagricultural, and industrial areas.

Wagner and others (2006), U.S. Environmental 

Protection Agency (1996), Hornsby and others (1996)

Propiconazole Alamo, Banner, Benit, Break, 

Bumper, Desmel, Fidis, Juno, Mantis, Maxx, Novel, Practis, Orbit, Radar, Restore, Spire, Taspa, Tilt, Wocosin

Fungicide 60207-90-1 Used on grasses grown for seed, many crops, 

conifors, hardwoods, and fruit trees.

Wagner and others (2006), Extension Toxicology 

Network (1997), Hornsby and others (1996)

Propoxur Arprocarb, Bay 9010, Bayer 39007, 

Baygon, Bifex, Blattanex, Bolfo, Invisigard, Mobay, PHC, Propogon, Propyon, Rhoden, Sendra, Sendran, Suncide, Tendex, UNDEN, Undene

Insecticide 114-26-1 Used to control insects in lawns, turf, and 

buildings.

Wagner and others (2006), Hornsby and others 

(1996), Extension Toxicology Network (1993e)

Siduron Tupersan, Trey Herbicide 1982-49-6 Preemergence treatment for turf. Wagner and others (2006), Hornsby and others 

(1996)

Triclopyr Access, Crossbow, Curtail, ET, 

Garlon, Grazon, Redeem, Turflon

Herbicide 55335-06-3 Selective systemic herbicide used for control 

of woody and broadleaf plants in turf and along rights-of-way.

Wagner and others (2006), Hornsby and others 

(1996), Extension Toxicology Network (1993f)

Data for the Cambridge Drinking-Water Source Area 23
24 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005

Table 7. Frequency of detection and maximum concentration of selected pesticides detected in base-flow and 

stormflow water samples collected in the Hobbs Brook and Stony Brook Reservoir basins, eastern Massachusetts, 

for water year 2005.

[E, the recovery or variation in recovery of the analyte was outside the acceptable range, or concentration reported is less than laboratory 

reporting level and is qualified as estimated]

Pesticide target analyte

Frequency of detection for 

water year 2005 

(percent)

Number of 

samples

Maximum concentration 

(micrograms per liter)

Caffeine 81 16 E1.69

2,4-D 31 16 E7.92

2-Chloro-6-ethylamino-4-amino-s-triazine 6 16 E.01

3-Ketocarbofuran 8 12 E.08

Benomyl 19 16 E.176

Carbaryl 25 16 .03

Diuron 25 16 E.14

Imazaquin 19 16 E.06

Imidacloprid 63 16 E1.00

MCPA 8 12 E.16

Metalaxyl 19 16 E.04

Metsulfuron 25 16 E3.90

Norflurazon 19 16 E.15

Propiconazole 19 16 E.54

Propoxur 6 16 E2.46

Siduron 44 16 E.06

Triclopyr 13 16 E1.44
Figure 9. Monthly precipitation totals for the Cambridge Reservoir, Stony Brook Reservoir, and Fresh Pond 

Reservoir in the Cambridge, Massachusetts, drinking-water source area for water year 2005.

0

1

2

3

4

5

6

7

WATER YEAR 2005

01104430 Cambridge Reservoir

01104480 Stony Brook Reservoir

422302071083801 Fresh Pond Reservoir

PRECIPITATION, IN INCHES

RESERVOIR

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

Data for the Cambridge Drinking-Water Source Area 25
26 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005

Figure 10. Monthly mean air temperatures for water year 2005 for the Cambridge Reservoir, compared to the period-ofrecord maximum and minimum monthly mean air temperatures and the median monthly air temperatures for water years 

2002–2004, eastern Massachusetts.

Monthly mean air temperature for 2005 water year

Median monthly air temperature for period 2002–2004

Unshaded area shows range between the highest and

 lowest monthly mean value for period of station record

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.

-10

-5

0

5

10

15

20

25

AIR TEMPERATURE, IN DEGREES CELSIUS

WATER YEAR

EXPLANATION
References Cited

American Public Health Association, 1998, Standard methods 

for the examination of water and wastewater (20th ed.); 

Washington, D.C., American Public Health Association, 

American Water Works Association, and Water Environment Federation, p. 3-37–3-43.

Anderson, C.W., 2004 (2d ed.), Turbidity, in Wilde, F.D., and 

Radtke, D.B., eds., Field measurements: U.S. Geological 

Survey Techniques of Water-Resources Investigations, 

book 9, chap. A6.7, 64 p., accessed April 7, 2005, at 

http://water.usgs.gov/owq/FieldManual/Chapter6/6.7_

contents.html

ASTM International, 2003, D1889–00 Standard test method 

for turbidity of water, in ASTM International, Annual Book 

of ASTM Standards, Water and Environmental Technology, 

v. 11.01: West Conshohocken, Pennsylvania, 6 p.

Benderly, A.A., 1962, Treatment of Teflon to promote bondability: Journal of Applied Polymer Science, v. 6, no. 20, 

p. 221–225.

Buchanan, T.J., and Somers, W.P., 1968, Stage measurements 

at gaging stations: Techniques of Water-Resources Investigations of the U.S. Geological Survey, book 3, chap. A7, 

28 p.

Buchanan, T.J., and Somers, W.P., 1969, Discharge measurements at gaging stations: Techniques of Water-Resources 

Investigations of the U.S. Geological Survey, book 3, 

chap. A8, 65 p.

Carter, R.W., and Davidian, Jacob, 1968, General procedure 

for gaging streams: Techniques of Water-Resources Investigations of the U.S. Geological Survey, book 3, chap. A6, 

13 p.

Extension Toxicology Network, 2005, Pesticide information 

profile for imidacloprid, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/haloxyfopmethylparathion/imidacloprid-ext.html

Extension Toxicology Network, 1997, Pesticide information 

profile for propiconazole, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/metirampropoxur/propiconazole-ext.html

Extension Toxicology Network, 1996, Pesticide information profile for imazaquin, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/haloxyfopmethylparathion/imazaquin-ext.html

Extension Toxicology Network, 1993a, Pesticide information profile for diuron, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlorglyphosate/diuron-ext.html

Extension Toxicology Network, 1993b, Pesticide information profile for MCPA, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/haloxyfopmethylparathion/mcpa-ext.html

Extension Toxicology Network, 1993c, Pesticide information profile for metalaxyl, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/haloxyfopmethylparathion/metalaxyl-ext.html

Extension Toxicology Network, 1993d, Pesticide information 

profile for metsulfuron-methyl, accessed on April 05, 2006, 

at http://pmep.cce.cornell.edu/profiles/extoxnet/metirampropoxur/metsulfuron-methyl-ext.html

Extension Toxicology Network, 1993e, Pesticide information 

profile for propoxur, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/metirampropoxur/propoxur-ext.html

Extension Toxicology Network, 1993f, Pesticide information 

profile for triclopyr, accessed on April 05, 2006, at 

http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrinsziram/triclopyr-ext.html

Fishman, M.J., ed., 1993, Methods of analysis by the U.S. 

Geological Survey National Water Quality Laboratory—

Determination of inorganic and organic constituents in 

water and fluvial sediments: U.S. Geological Survey OpenFile Report 93–125, 217 p.

Fishman, M.J., and Friedman, L.C., 1989, Methods for 

determination of inorganic substances in water and fluvial 

sediments: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. A1, 545 p.

Fugro East, Inc., 1996, Limnological investigations of the 

Cambridge Reservoir system—Impacts of watershed inputs 

and alum sludge discharge: Cambridge, Mass., Cambridge 

Water Department, 77 p., plus appendixes.

Furlong, E.T., Anderson, B.D., Werner, S.L., Soliven, P.P., 

Coffey, L.J., and Burkhardt, M.R., 2001, Methods of 

analysis by the U.S. Geological Survey National Water 

Quality Laboratory—Determination of pesticides in water 

by graphitized carbon-based solid-phase extraction and 

high-performance liquid chromatography/mass spectrometry: U.S. Geological Survey Water-Resources Investigations 

Report 01–4134, 73 p.

Furlong, E.T., Vaught, D.G., Merten, L.M., Foreman, W.T., 

and Gates, P.M., 1996, Methods of analysis by the U.S. 

Geological Survey National Water Quality Laboratory—

Determination of semivolatile organic compounds in bottom 

sediment by solvent extraction, gel permeation chromatographic fractionation, and capillary-column gas chromatography/mass spectrometry: U.S. Geological Survey OpenFile Report 95–719, 67 p.

References Cited 27
28 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005

Rantz, S.E. and others, 1982, Measurement and computation 

of streamflow—Volume 1. Measurement of stage and discharge: U.S. Geological Survey Water Supply Paper 2175, 

284 p.

Seiler, R.L., Zaugg, S.D., Thomas, J.M., and Howcroft, D.L., 

1999, Caffeine and pharmaceuticals as indicators of waste 

water contamination in wells: Ground Water, v. 37, no. 3, 

p. 405–410.

Sholar, C.J., and Shreve, E.A., 1998, Quality-assurance plan 

for the analysis of fluvial sediment by the northeastern 

region, Kentucky District Sediment Laboratory: U.S. Geological Survey Open-File Report 98–348, 20 p.

Smith, K.P., 2005, Hydrologic, water-quality, bed-sediment, 

soil-chemistry, and statistical summaries of data for the 

Cambridge, Massachusetts, drinking-water source area, 

water year 2004: U.S. Geological Survey Open-File Report 

2005–1383, 110 p.

Socolow, R.S., Comeau, L.Y., Zanca, J.L., and Ramsbey, L.R., 

1999, Water-resources data for Massachusetts and Rhode 

Island, water year 1998: U.S. Geological Survey WaterData Report MA-RI-98-1, 438 p.

Socolow, R.S., Girouard, G.G., Whitley, J.F., and Ramsbey, 

L.R., 2003, Water-resources data for Massachusetts and 

Rhode Island, water year 2002: U.S. Geological Survey 

Water-Data Report MA-RI-02-1, 339 p.

Socolow, R.S., Leighton, J.F., Whitley, J.F., and Ventetuolo, 

D.J., 2002, Water-resources data for Massachusetts and 

Rhode Island, water year 2001: U.S. Geological Survey 

Water-Data Report MA-RI-01-1, 307 p.

Socolow, R.S., Whitley, J.S., Murino, Jr. D., and Ramsbey, 

L.R., 2001, Water-resources data for Massachusetts and 

Rhode Island, water year 2000: U.S. Geological Survey 

Water-Data Report MA-RI-00-1, 459 p.

Socolow, R.S., Zanca, J.L., Driskell, T.R., and Ramsbey, L.R., 

2004, Water-resources data for Massachusetts and Rhode 

Island, water year 2003: U.S. Geological Survey WaterData Report MA-RI-03-1, 368 p.

Socolow, R.S., Zanca, J.L., Murino, Jr. D., and Ramsbey, L.R., 

2000, Water-resources data for Massachusetts and Rhode 

Island, water year 1999: U.S. Geological Survey WaterData Report MA-RI-99-1, 401 p.

U.S. Environmental Protection Agency, 2006a, Consumer 

factsheet on 2,4-D, accessed on April 05, 2006, at 

http://www.epa.gov/safewater/contaminants/dw_

contamfs/24-d.html

U.S. Environmental Protection Agency, 2006b, Consumer 

factsheet on carbofuran, accessed on April 05, 2006, at 

http://www.epa.gov/safewater/contaminants/dw_contamfs/

carbofur.html

Garbarino, J.R., and Struzeski, T.M., 1998, Methods of analysis by the U.S. Geological Survey National Water Quality 

Laboratory—Determination of elements in whole-water 

digests using inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-mass 

spectrometry: U.S. Geological Survey Open-File Report 

98–165, 101 p.

Guy, H.P., 1970, Fluvial sediment concepts: U.S. Geological 

Survey Techniques of Water-Resources Investigations, 

book 3, chap. C1, 55 p.

Hoffman, G.L., Fishman, M.J., and Garbarino, J.R., 1996, 

Methods of analysis by the U.S. Geological Survey National 

Water Quality Laboratory—In-bottle acid digestion of 

whole-water samples: U.S. Geological Survey Open-File 

Report 96–225, 28 p.

Hornsby, A.G., Wauchope, R.D., and Herner, A.E., 1996, 

Pesticide properties in the environment: New York, 

Springer-Verlag, 227 p.

Kennedy, E.J., 1983, Computation of continuous records of 

streamflow: Techniques of Water-Resources Investigations 

of the U.S. Geological Survey, book 3, chap. A13, 52 p.

Kennedy, E.J., 1984, Discharge ratings at gaging stations: 

Techniques of Water-Resources Investigations of the 

U.S. Geological Survey, book 3, chap. A10, 59 p.

McLain, Betty, 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of chromium in water by graphite furnace atomic 

absorption spectrophotometry: U.S. Geological Survey 

Open-File Report 93–449, 16 p. 

Myers, D.N., and Sylvester, M.A., 1997, National field 

manual for the collection of water-quality data—Biological 

indicators: U.S. Geological Survey Techniques of WaterResources Investigations, book 9, chap. A7, variously 

paged.

Oberg, K.A., Morlock, S.E., and Caldwell, W.S., 2005, 

Quality-assurance plan for discharge measurements using 

acoustic Doppler current profilers: U.S. Geological Survey 

Scientific Investigations Report 2005–5183, 35 p.

Patterson, Glenn, 1997, The U.S. Geological Survey drinking 

water initiative: U.S. Geological Survey Fact Sheet 047–97, 

2 p.

Patton, C.J., and Kryskalla, J.R., 2003, Methods of analysis 

by the U.S. Geological Survey National Water Quality 

Laboratory—Evaluation of alkaline persulfate digestion 

as an alternative to kjeldahl digestion for determination of 

total and dissolved nitrogen and phosphorus in water: U.S. 

Geological Survey Water-Resources Investigations Report 

03–4174, 33 p.
U.S. Environmental Protection Agency, 2004a, RED FACTS 

MCPA, accessed on April 05, 2006, at http://www.epa.

gov/oppsrrd1/REDs/factsheets/mcpa_red_fs.pdf

U.S. Environmental Protection Agency, 2004b, Carbaryl IRED 

Facts, accessed on April 05, 2006, at http://www.epa.gov/

oppsrrd1/REDs/factsheets/carbaryl_factsheet.pdf

U.S. Environmental Protection Agency, 2002a, List of 

National Secondary Drinking Water Regulations, accessed 

on March 14, 2005, at http://www.epa.gov/safewater/mcl.

html#sec

U.S. Environmental Protection Agency, 2002b, Method 

1603—Escherichia coli (E. coli) in Water by membrane 

filtration using modified membrane-thermotolerant Escherichia coli agar (Modified mTEC): Washington, D.C., 

EPA-821-R-02-023, September 2002.

U.S. Environmental Protection Agency, 2001, Benomyl RED 

Facts: Benomyl Fact Sheet, EPA-738-F-02-001.

U.S. Environmental Protection Agency, 1996, RED FACTS 

Norflurazon, accessed on April 05, 2006, at http://www.epa.

gov/oppsrrd1/REDs/factsheets/0229fact.pdf

U.S. Environmental Protection Agency, 1994, RED FACTS 

Metalaxyl, accessed on April 05, 2006, at http://www.epa.

gov/oppsrrd1/REDs/factsheets/0081fact.pdf

Wagner, R.J., Boulger, R.W., Jr., Oblinger, C.J., and Smith, 

B.A., 2006, Guidelines and standard procedures for continuous water-quality monitors—Station operation, record 

computation, and data reporting: U.S. Geological Survey 

Techniques and Methods 1–D3, 51 p., plus 8 attachments, 

accessed on April 10, 2006, at http://pubs.water.usgs.

gov/tm1d3

Wagner, R.J., Frans, L.M., and Huffman, R.L., 2006, Occurrence, distribution, and transport of pesticides in agricultural irrigation return flow from four drainage basins in 

the Columbia Basin Project, Washington, 2002–2004, and 

comparison with historical data: U.S. Geological Survey 

Scientific Investigations Report 2006–5005, 54 p.

Waldron, M.C., and Bent, G.C., 2001, Factors affecting 

reservoir and stream-water quality in the Cambridge, 

Massachusetts, drinking-water source area and implications 

for source-water protection: U.S. Geological Survey WaterResources Investigations Report 00–4262, 89 p.

Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, 

L.E., eds., 1987, Methods for the determination of organic 

substances in water and fluvial sediments: U.S. Geological 

Survey Techniques of Water-Resources Investigations, 

book 5, chap. A3, 80 p.

Wilde, F.D., Radtke, D.B., Gibs, Jacob, and Iwatsubo, R.T., 

eds., September 1999, Collection of water samples: U.S. 

Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A4, accessed on November 2, 2006, 

at http://pubs.water.usgs.gov/twri9A4/

References Cited 29

Tables 8–16
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

October

1 0.40 0.64 0.30 0.31 26 1.1 e0.13

2 .37 .66 .26 .30 17 .87 e.13

3 .33 .61 .26 .22 15 .75 e.20

4 .26 .53 .17 .19 15 .71 e.41

5 .22 .54 .15 .16 14 .58 .16

6 .19 .54 .14 .15 12 .54 .16

7 .17 .54 .13 .13 11 .51 .16

8 .15 3.1 .12 .13 11 .47 .16

9 .14 7.8 .12 .13 16 .48 .16

10 .14 7.2 .11 .13 15 .42 .16

11 .14 3.5 .10 .13 13 .34 .16

12 .16 .75 .13 .14 8.8 .33 .22

13 .12 .75 .10 .13 8.0 .33 .22

14 .12 3.6 .10 .14 8.6 .35 .22

15 .40 5.4 .37 .64 13 .41 .26

16 1.6 5.5 1.1 1.3 26 1.2 .43

17 .26 5.4 .17 .15 20 .64 .34

18 .19 2.9 .14 .13 16 .52 .26

19 .69 .88 .87 .91 16 .76 .55

20 .31 .88 .24 .18 15 .72 .55

21 .24 .84 .16 .15 13 .58 .55

22 .22 .81 .14 .13 12 .52 .55

23 .19 .80 .13 .13 11 .50 .55

24 .18 3.0 .13 .13 10 .49 .55

25 .16 4.4 .13 .13 12 .47 .55

26 .14 4.4 .12 .13 12 .45 .54

27 .13 4.5 .12 .12 11 .42 .49

28 .11 4.4 .11 .12 11 .37 .43

29 .13 4.3 .11 .13 11 .39 .43

30 .14 7.4 .14 .14 12 .41 .55

31 .13 9.2 .11 .15 16 .38 .48

Total 8.13 95.77 6.48 7.16 427.4 17.01 10.71

Mean .26 3.09 .21 .23 13.8 .55 .35

Maximum 1.6 9.2 1.1 1.3 26 1.2 .55

Minimum .11 .53 .10 .12 8.0 .33 .13

Median .18 3.0 .13 .14 13 .49 .34

Mgal/d/mi2 .64 — .58 .48 — .65 —

Inches 1.13 — 1.03 .86 — 1.15 —

32 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

November

1 0.11 9.2 0.09 0.16 15 0.31 0.55

2 .10 9.2 .08 .16 14 .37 .49

3 .12 9.4 .10 .19 15 .36 .55

4 .65 9.5 .27 1.0 16 .43 .55

5 .69 9.6 .56 .34 24 .71 .55

6 .19 9.8 .12 .21 20 .51 1.5

7 .15 9.8 .10 .19 19 .47 1.5

8 .13 9.7 .09 .16 17 .42 1.6

9 .12 9.6 .08 .16 16 .40 1.5

10 .15 9.6 .08 .15 15 .38 1.5

11 .11 9.5 .08 .16 16 .38 1.6

12 .17 9.5 .12 .33 16 .38 1.8

13 .28 9.4 .17 .35 18 .44 1.9

14 .16 9.4 .12 .17 17 .41 2.1

15 .23 9.4 .15 .26 17 .43 2.3

16 .22 9.4 .14 .23 17 .45 2.3

17 .21 8.2 .14 .24 17 .47 2.3

18 .22 6.2 .12 .18 16 .47 2.3

19 .17 3.9 .08 .16 13 e.50 2.3

20 .17 3.0 .10 .23 11 e.47 2.5

21 .26 2.9 .21 .17 12 e.47 2.5

22 .15 1.7 .10 .11 11 e.48 2.5

23 .12 .45 .09 .10 9.4 .44 2.5

24 .27 .40 .23 .32 9.5 .46 2.5

25 .66 .43 .58 .55 14 .72 2.8

26 .25 .37 .19 .14 13 .59 3.0

27 .18 .32 .09 .13 11 .53 3.0

28 1.9 .30 .60 2.3 18 1.1 3.0

29 .67 .33 .96 .42 31 1.9 .78

30 .41 .32 .21 .31 23 1.2 7.1

Total 9.22 180.82 6.05 9.58 480.9 16.65 61.37

Mean .31 6.03 .20 .32 16 .56 2.05

Maximum 1.9 9.8 .96 2.3 31 1.9 7.1

Minimum .10 .30 .08 .10 9.4 .31 .49

Median .18 9.2 .12 .19 16 .47 2.2

Mgal/d/mi2 .75 — .56 .67 — .65 —

Inches 1.3 — .97 1.15 — 1.13 —

Table 8 33
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

December

1 1.5 0.29 0.84 1.6 28 1.4 38

2 .55 .30 .33 .45 29 1.4 31

3 .45 .27 .20 .39 23 1.1 .84

4 .38 .23 .16 .36 20 .95 .90

5 .35 .23 .14 .33 18 .88 24

6 .31 .23 .12 .32 15 .80 24

7 2.3 .27 .81 2.6 23 1.4 11

8 1.1 .33 1.0 1.1 41 2.1 12

9 .61 .36 .27 .74 37 1.6 12

10 1.4 .39 .62 1.9 33 1.7 23

11 1.9 .45 .98 1.8 48 2.3 35

12 .77 .49 .32 1.0 41 1.8 36

13 .64 .52 .24 .89 33 1.5 36

14 .54 .52 .20 .78 29 1.3 20

15 .46 .52 .15 .71 24 1.2 20

16 .44 .54 .13 .70 21 1.1 20

17 .43 .54 .12 .65 20 1.1 20

18 .38 .52 .10 .56 19 .98 9.7

19 .39 .54 .11 .57 18 .95 .22

20 .42 .56 .19 .60 19 1.1 .26

21 .33 .56 .11 e.41 17 .92 .22

22 .34 .56 .16 .46 16 .89 .26

23 2.6 .61 .40 2.7 22 1.4 13

24 1.2 .75 1.1 1.0 49 2.4 28

25 .58 .77 .23 .70 42 1.8 19

26 .51 .78 e.15 e.56 31 1.5 19

27 .49 .85 e.15 e.56 25 1.4 25

28 .45 4.1 e.15 e.56 23 e1.2 48

29 .44 9.9 e.15 e.56 29 e1.2 48

30 .41 14 e.15 e.55 33 e.89 26

31 .51 15 e.27 e.71 35 e1.0 21

Total 23.18 55.98 e10.05 e26.82 861 e41.26 621.4

Mean .75 1.81 e.32 e.87 27.8 e1.33 20

Maximum 2.6 15 1.1 2.7 49 2.4 48

Minimum .31 .23 .10 .32 15 e.80 .22

Median .49 .52 e.19 e.65 25 e1.2 20

Mgal/d/mi2 1.82 — e.90 e1.8 — e1.57 —

Inches 3.24 — e1.6 e3.2 — e2.79 —

34 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

January

1 0.73 15 e0.34 e0.97 38 e1.3 e23

2 .54 15 e.28 e.78 38 e1.4 e26

3 .71 15 e.32 e.90 39 e1.3 e29

4 1.5 15 .83 1.7 52 2.0 37

5 .73 15 .29 .98 51 1.7 43

6 .88 15 .40 1.4 48 1.7 43

7 .87 15 .62 1.2 49 1.7 43

8 .69 15 .29 1.1 48 1.7 43

9 .61 15 .25 .92 45 1.6 43

10 .63 15 .23 .92 43 1.5 34

11 .55 15 .18 .83 41 1.4 28

12 1.0 15 .56 1.5 43 1.6 36

13 1.0 15 .64 1.4 48 1.8 42

14 5.3 15 1.5 3.9 81 4.1 43

15 1.5 15 .94 2.1 106 3.4 52

16 1.1 15 .36 1.8 84 2.8 69

17 .92 15 .28 1.6 70 2.3 60

18 .72 15 .19 e1.3 58 1.9 51

19 .65 15 .17 e1.2 50 1.7 44

20 .65 15 .15 1.2 49 1.7 44

21 .55 15 .14 e1.0 46 1.5 43

22 .50 15 .18 e.91 43 1.4 43

23 .53 15 .10 e.86 42 1.5 42

24 .48 15 .12 e.83 43 1.3 42

25 .46 15 .12 .77 42 1.2 30

26 .44 15 .12 .73 41 1.2 23

27 .40 14 .11 e.65 40 1.1 23

28 .38 14 .09 e.64 38 .99 23

29 .38 14 .09 e.64 37 .96 23

30 .37 14 .09 .58 36 .95 33

31 .34 14 .07 .53 35 .91 32

Total 26.11 460 e10.05 e35.84 1,524 e51.61 e1,190

Mean .84 14.8 e.32 e1.2 49 e1.7 e38.4

Maximum 5.3 15 1.5 3.9 106 4.1 69

Minimum .34 14 e.07 e.53 35 e.91 e23

Median .65 15 .23 e.97 43 e1.5 e42

Mgal/d/mi2 2.05 — e.90 e2.41 — e1.96 —

Inches 3.67 — e1.62 e4.29 — e3.49 —

Table 8 35
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

February

1 0.34 14 0.07 e0.54 34 0.85 28

2 .33 14 .07 e.54 33 .82 23

3 .38 14 .13 .73 33 .83 20

4 .47 14 .31 .80 35 .94 15

5 .42 14 .21 .69 34 .87 12

6 .41 14 .18 .64 34 .84 12

7 .41 11 .15 .59 31 .83 16

8 .42 8.7 .14 .59 26 .83 20

9 .50 8.7 .22 .71 26 .88 20

10 2.2 8.9 1.5 2.6 42 1.9 20

11 .94 8.9 .63 1.3 47 1.8 20

12 .70 8.9 .32 1.1 41 1.4 31

13 .58 8.8 .23 1.0 37 1.2 34

14 .54 8.7 .18 .93 33 1.1 31

15 2.5 9.0 1.4 2.6 49 2.2 32

16 2.1 8.9 .82 2.0 56 2.5 39

17 1.3 9.0 .77 1.7 66 2.6 45

18 .93 9.1 .34 1.4 57 2.0 45

19 .74 9.1 .24 1.3 48 1.7 45

20 .65 9.0 .20 1.2 42 1.6 44

21 .66 9.0 .23 1.1 40 1.6 44

22 .61 9.1 .26 .98 39 1.5 34

23 .57 9.0 .23 .88 38 1.4 26

24 .52 9.0 .17 .77 36 1.3 26

25 .54 9.0 .19 .79 35 1.3 26

26 .48 9.0 .16 .70 33 1.1 26

27 .44 9.0 .13 .64 32 1.1 22

28 .44 9.0 .13 .65 30 1.0 20

Total 21.12 282.8 9.61 29.47 1,087 37.99 776

Mean .75 10.1 .34 1.05 38.8 1.36 27.7

Maximum 2.5 14 1.5 2.6 66 2.6 45

Minimum .33 8.7 .07 .54 26 .82 12

Median .54 9.0 .22 .84 35 1.2 26

Mgal/d/mi2 1.84 — .95 2.19 — 1.6 —

Inches 2.97 — 1.54 3.52 — 2.57 —

36 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

March

1 0.50 5.1 0.20 0.68 30 1.1 20

2 .44 1.5 .18 .62 24 0.99 12

3 .39 1.6 .14 .52 22 .92 10

4 .37 1.5 .11 .49 20 .86 13

5 .38 1.5 .12 .42 20 .84 7.5

6 .39 1.5 .12 .44 19 .81 9.1

7 .49 1.5 .32 .60 20 .87 12

8 1.1 1.6 .84 1.2 28 1.5 12

9 .63 1.7 .34 .70 31 1.5 12

10 .52 1.7 .22 .59 28 1.1 16

11 .48 1.8 .19 .58 24 .96 21

12 .62 1.8 .36 1.0 25 1.1 21

13 .67 1.9 .55 .90 27 1.0 21

14 .62 1.9 .42 .78 26 .98 21

15 .68 1.9 .48 .64 26 .96 21

16 .71 2.0 .43 .56 26 1.0 21

17 .69 2.0 .36 .52 26 1.0 21

18 .69 2.0 .34 .55 26 1.1 20

19 .70 2.2 .32 .56 26 1.1 20

20 .73 2.5 .29 .60 28 1.2 20

21 .75 3.0 .30 .62 29 1.3 20

22 .78 3.6 .29 .63 31 1.4 20

23 .70 4.5 .24 .57 33 1.5 20

24 1.0 6.1 .73 1.0 37 1.5 21

25 .81 7.1 .38 .61 39 1.5 21

26 .74 7.9 .28 .56 40 1.6 21

27 .74 8.5 .26 .53 40 1.6 21

28 5.3 11 1.3 3.7 65 3.1 31

29 4.1 24 2.8 3.3 162 5.5 79

30 1.6 30 1.8 2.0 159 4.1 140

31 1.3 29 .49 1.7 136 3.5 149

Total 29.62 173.9 15.2 28.17 1273 47.49 873.6

Mean .96 5.61 .49 .91 41.1 1.53 28.2

Maximum 5.3 30 2.8 3.7 162 5.5 149

Minimum .37 1.5 .11 .42 19 .81 7.5

Median .69 2.0 .32 .61 28 1.1 20

Mgal/d/mi2 2.33 — 1.36 1.89 — 1.8 —

Inches 4.17 — 2.41 3.39 — 3.2 —

Table 8 37
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

April

1 1.1 26 0.39 1.5 114 3.1 194

2 3.1 28 1.3 3.2 127 4.0 168

3 3.8 37 2.0 4.2 175 5.2 164

4 1.4 37 1.2 1.9 160 3.9 144

5 1.1 29 .44 1.7 130 3.2 100

6 .95 24 .36 1.5 100 2.6 82

7 .88 22 .31 1.4 86 2.2 67

8 1.2 23 .78 1.9 87 2.4 59

9 .82 23 .28 1.2 81 2.0 60

10 .77 21 .24 1.1 69 1.8 53

11 .61 19 .20 1.0 60 1.6 39

12 .55 17 .19 .98 53 1.5 30

13 .54 16 .19 .96 50 1.4 30

14 .50 15 .16 .93 46 1.3 30

15 .45 13 .14 .89 42 1.2 30

16 .44 12 .13 .88 39 1.1 19

17 .43 11 .11 .88 36 1.0 12

18 .39 11 .11 .88 34 .95 12

19 .37 9.3 .10 .87 31 .90 12

20 .36 8.9 .10 .91 29 .81 12

21 .50 9.3 .40 .97 30 .85 12

22 .33 8.7 .13 .73 27 .84 12

23 .89 9.2 .72 1.4 30 1.2 13

24 1.4 12 1.4 1.7 46 1.8 30

25 .77 12 .65 .94 48 1.5 40

26 .47 12 .26 .66 41 1.1 40

27 .91 12 .87 1.4 40 1.2 40

28 .67 13 .59 .82 45 1.5 39

29 .49 12 .28 .71 40 1.2 39

30 .88 12 .62 1.4 37 1.2 39

Total 27.07 514.4 14.65 39.51 1,933 54.55 1,621

Mean .90 17.1 .49 1.32 64.4 1.82 54

Maximum 3.8 37 2.0 4.2 175 5.2 194

Minimum .33 8.7 .10 .66 27 .81 12

Median .72 13 .29 1.0 46 1.4 39

Mgal/d/mi2 2.2 — 1.36 2.74 — 2.14 —

Inches 3.81 — 2.34 4.74 — 3.69 —

38 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

May

1 0.84 13 1.2 1.1 45 1.5 39

2 .53 13 .36 .81 42 1.3 31

3 .50 12 .33 .82 38 1.1 21

4 .41 12 .27 .73 34 .99 21

5 .37 11 .22 .71 32 .92 21

6 .36 9.9 .20 .69 29 .87 21

7 1.4 11 1.6 2.2 37 1.5 21

8 .65 13 .59 .89 44 1.5 21

9 .51 13 .27 .81 39 1.2 22

10 .46 12 .21 .77 36 1.0 22

11 .42 11 .18 .76 33 .94 22

12 .37 11 .15 .74 29 .85 12

13 .34 9.5 .12 .73 26 .79 .32

14 .34 8.9 .12 .72 25 .77 .34

15 .33 8.5 .11 .72 23 .73 2.6

16 .47 8.6 .62 1.1 28 .89 11

17 .32 8.1 .14 .58 24 .80 13

18 .36 8.0 .11 .56 21 .60 10

19 .31 7.8 .10 .56 21 .68 7.3

20 .28 7.4 .08 .53 19 .68 19

21 .28 7.2 .09 .55 18 .64 30

22 .65 7.7 .52 .95 23 .75 30

23 .47 7.9 .21 .69 21 .70 30

24 1.8 9.6 1.6 2.0 34 1.0 30

25 2.9 14 2.0 2.9 59 2.1 72

26 3.5 21 1.8 3.1 101 3.3 94

27 1.2 22 .62 1.4 87 2.1 71

28 .89 21 .31 1.3 64 1.7 53

29 .79 19 .38 1.5 53 1.5 39

30 .68 17 .24 1.1 48 1.4 39

31 .61 16 .22 1.0 43 1.3 39

Total 23.34 371.1 14.97 33.02 1,176 36.1 864.56

Mean .75 12 .48 1.07 37.9 1.16 27.9

Maximum 3.5 22 2.0 3.1 101 3.3 94

Minimum .28 7.2 .08 .53 18 .60 .32

Median .47 11 .24 .81 34 .99 22

Mgal/d/mi2 1.84 — 1.34 2.22 — 1.37 —

Inches 3.27 — 2.42 3.96 — 2.44 —

Table 8 39
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

June

1 0.55 15 0.24 0.93 39 1.2 39

2 .51 14 .14 .86 36 1.0 22

3 .47 13 .12 .81 33 0.94 13

4 .43 12 .09 .75 29 .84 5.1

5 .39 11 .07 .70 26 .79 .24

6 .38 10 .05 .66 23 .72 .25

7 .35 9.3 .06 .63 22 .66 .28

8 1.4 8.8 .19 1.7 22 .62 .35

9 1.5 12 1.0 1.1 42 1.6 3.4

10 .47 11 .17 .60 38 1.0 19

11 .39 11 .12 .53 30 .83 44

12 .36 9.9 .11 .49 26 .72 34

13 .34 9.1 .10 .47 22 .65 13

14 .39 8.9 .41 .51 21 .64 13

15 .56 8.9 .27 .61 20 .66 6.3

16 .48 8.5 .18 .72 19 .70 .21

17 .51 8.6 .32 .54 21 .85 .23

18 .34 8.2 .12 .39 19 .70 .21

19 .30 7.8 .11 .36 19 .66 .22

20 .27 7.4 .10 .33 17 .63 .24

21 .25 7.1 .08 .33 14 .53 .31

22 .26 7.0 .10 .33 13 .37 .35

23 .21 6.7 .08 .28 13 .33 .36

24 .18 6.5 .07 .27 12 .28 .39

25 .16 6.4 .08 .26 11 e.25 .45

26 .11 6.3 .13 .26 12 e.26 .44

27 .10 6.3 .08 .25 12 e.26 .43

28 .11 6.2 .10 .25 11 e.26 .39

29 .11 7.8 .07 .24 11 e.26 .44

30 .10 10 .07 .23 13 e.26 .49

Total 11.98 274.7 4.83 16.39 646 e19.47 218.08

Mean .40 9.16 .16 .55 21.5 e.65 7.27

Maximum 1.5 15 1.0 1.7 42 1.6 44

Minimum .10 6.2 .05 .23 11 e.25 .21

Median .35 8.9 .11 .50 21 e.66 .43

Mgal/d/mi2 .97 — .45 1.14 — e.76 —

Inches 1.67 — .78 1.97 — e1.32 —

40 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

July

1 0.10 13 0.08 0.23 15 e0.26 0.49

2 .08 15 .07 .23 19 e.26 .48

3 .07 15 .06 .23 19 e.26 .51

4 .06 15 .06 .22 19 e.26 .43

5 .06 15 .06 .22 17 e.26 .42

6 .82 15 1.4 3.2 37 e2.8 .60

7 .15 7.2 .39 .16 34 e1.9 23

8 2.3 1.4 .56 2.5 24 1.6 37

9 1.2 1.5 1.3 .85 45 2.3 36

10 .34 1.5 .34 .27 35 1.3 36

11 .17 1.4 .15 .21 21 .79 16

12 .12 12 .12 .19 19 .62 .20

13 .10 15 .10 .18 26 .53 .19

14 .08 14 .10 .17 22 .46 .22

15 .06 13 .08 .16 20 .41 .24

16 .05 13 .08 .16 19 .35 .23

17 .04 13 .08 .16 18 .30 .24

18 .04 13 .08 .15 18 .30 .27

19 .03 13 .08 .14 18 .28 .30

20 .02 13 .07 .14 17 .23 .35

21 .01 13 .06 .13 16 .21 .37

22 .01 13 .17 .42 16 .20 .39

23 .01 13 .29 .15 17 .18 .38

24 .01 12 .08 .13 15 .16 .38

25 .01 12 .07 .13 15 .15 .43

26 .01 13 .07 .12 15 .14 .49

27 .01 15 .07 .11 16 .13 .49

28 .01 17 .08 .11 19 .12 .51

29 .00 17 .06 .11 19 .11 .50

30 .00 16 .07 .11 18 .10 .55

31 .01 16 .06 .11 18 .11 .55

Total 5.98 377 6.34 11.4 646 e17.08 158.21

Mean .19 12.2 .20 .37 20.8 e.55 5.1

Maximum 2.3 17 1.4 3.2 45 e2.8 37

Minimum .00 1.4 .06 .11 15 e.10 .19

Median .05 13 .08 .16 19 e.26 .43

Mgal/d/mi2 .47 — .57 .77 — e.65 —

Inches .84 — 1.01 1.36 — e1.15 —

Table 8 41
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

August

1 0.02 16 0.15 0.13 18 0.10 0.58

2 2.0 17 1.2 2.1 32 .53 .44

3 .04 16 .12 .12 22 .27 .30

4 .02 16 .09 .11 20 .23 .30

5 .02 16 .08 .11 19 .23 .32

6 .01 17 .06 .11 19 .21 .30

7 .01 16 .06 .11 19 .19 .29

8 .01 16 .07 .10 18 .18 .28

9 .01 16 .06 .11 18 .18 .29

10 .01 16 .05 .11 17 .16 .28

11 .01 16 .05 .11 17 .14 .34

12 .01 16 .05 .12 17 .14 .31

13 .01 16 .05 .12 17 .13 .32

14 1.4 16 .64 1.9 23 .39 .43

15 .23 16 .91 .57 31 .31 .36

16 .03 16 .13 .12 23 .18 .29

17 .01 16 .09 .11 20 .13 .26

18 .01 15 .07 .11 18 .11 .26

19 .01 15 .06 .11 17 .11 .26

20 .01 15 .06 .11 17 .10 .26

21 .04 15 .08 .14 17 .11 .25

22 .01 15 .06 .11 17 .10 .19

23 .01 15 .05 e.16 17 .09 .23

24 .01 15 .04 e.15 16 .08 .30

25 .01 15 .04 e.16 16 .08 .31

26 .01 15 .04 e.17 16 .08 .30

27 .01 15 .04 e.15 15 .07 .30

28 .01 15 .04 e.16 16 .07 .32

29 .01 7.3 .07 e.16 13 .08 14

30 .07 2.7 .14 e.23 7.3 .10 22

31 .01 2.8 .08 e.17 5.8 .08 21

Total 4.08 451.8 4.73 e8.25 558.1 4.96 65.67

Mean .13 14.6 .15 e.27 18 .16 2.12

Maximum 2.0 17 1.2 2.1 32 .53 22

Minimum .01 2.7 .04 .10 5.8 .07 .19

Median .01 16 .06 e.12 17 .13 .30

Mgal/d/mi2 .32 — .42 e.55 — .19 —

Inches .56 — .75 e.98 — .34 —

42 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

September

1 0.06 11 0.10 e0.20 8.6 0.08 7.90

2 .01 16 .04 e.16 16 .07 .11

3 .01 16 .03 e.15 17 .07 .08

4 .01 16 .04 e.15 16 .07 .10

5 .01 16 .03 e.18 17 .06 .13

6 .00 16 .03 e.16 16 .06 .10

7 .00 16 .03 e.12 16 .06 .08

8 .00 16 .03 e.12 16 .06 .09

9 .00 16 .03 e.15 16 .06 .10

10 .00 16 .02 e.13 16 .06 .10

11 .00 16 .02 e.12 15 .06 .10

12 .00 16 .02 e.10 16 .05 .12

13 .00 16 .02 e.11 16 .05 .17

14 .00 16 .02 e.15 15 .05 .20

15 .63 16 .63 e.79 18 .17 .24

16 .01 16 .15 e.11 17 .08 .16

17 .03 16 .11 e.13 17 .07 .16

18 .03 19 .06 e.16 18 .07 .17

19 .00 20 .05 e.13 21 .06 .20

20 .00 20 .05 e.12 21 .07 .21

21 .00 20 .05 e.12 21 .06 .22

22 .00 20 .04 e.12 20 .05 .24

23 .00 20 .04 e.12 20 .05 .25

24 .00 20 .03 e.13 20 .05 .24

25 .00 20 .03 e.14 20 .05 .20

26 .00 15 .07 e.13 18 .05 .22

27 .00 16 .16 e.13 13 .06 .29

28 .00 21 .05 e.18 22 .05 .32

29 .17 21 .47 e.29 24 .11 .37

30 .01 20 .14 e.12 22 .06 .33

Total .98 519 2.59 e4.92 528.6 1.97 13.2

Mean .03 17.3 .09 e.16 17.6 .07 .44

Maximum .63 21 .63 e.79 24 .17 7.9

Minimum .00 11 .02 e.10 8.6 .05 .08

Median .00 16 .04 e.13 17 .06 .18

Mgal/d/mi2 .08 — .24 e.34 — .08 —

Inches .14 — .42 e.58 — .13 —

Table 8 43
44 Hydrol

Table 8. Daily, monthly, and annual statistics for discharge for U.S. Geological Survey stations in the drinking-water source area for 

Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated; —, no data; Mgal/d/mi2, million gallons per day per square mile; %, percent]

Month and 

date

Cambridge 

Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, 

unnamed 

tributary 1, near 

Kendal Green 

(01104433)

Stony Brook, 

unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook 

at Route 20 

at Waltham 

(01104460)

Stony Brook 

Reservoir, 

unnamed 

tributary 1, 

near Weston 

(01104475)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Annual total 190.70 3,755.90 105.60 250.40 11,145.80 345.70 6,483.30

Annual 

mean

.52 10.28 .29 .69 30.51 .95 17.78

Annual 

mgal/d/mi2 1.27 — .81 1.43 — 1.12 —

Annual 

inches

26.77 — 16.89 30 — 23.4 —

10 percent 

exceeds 1.10 16.16 .71 1.49 48.48 1.81 43.31

50 percent 

exceeds .38 9.70 .15 .56 22.63 .84 10.99

90 percent 

exceeds

.01 0.63 .06 .12 13.58 .10 0.22

Remarks Good Good Good1 Good2 Good1 Good1 Good1

1

Records that are estimated are rated as poor.

2

Records that are estimated are rated as fair.

ogic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

October

1 178.40 78.50 16.68

2 178.42 77.99 16.68

3 178.47 77.50 16.68

4 178.50 77.49 16.66

5 178.55 77.56 16.63

6 178.59 77.49 16.59

7 178.64 77.35 16.53

8 178.64 77.57 16.3

9 178.62 77.81 16.12

10 178.58 77.94 16.09

11 178.55 77.96 16.09

12 178.60 77.75 16.09

13 178.63 77.40 16.05

14 178.65 77.05 16.03

15 178.64 76.84 16.06

16 178.75 77.19 16.18

17 178.78 77.53 16.22

18 178.79 77.65 16.23

19 178.87 77.66 16.31

20 178.95 77.74 16.35

21 179.00 77.68 16.4

22 179.04 77.52 16.42

23 179.08 77.30 16.44

24 179.10 77.05 16.52

25 179.08 76.86 16.52

26 179.06 76.69 16.53

27 179.06 76.52 16.56

28 179.05 76.33 16.59

29 179.04 76.15 16.61

30 179.04 76.04 16.62

31 179.01 76.11 16.62

Mean 178.78 77.30 16.4

Maximum 179.10 78.50 16.68

Minimum 178.40 76.04 16.03

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

November

1 178.94 76.24 16.59

2 178.90 76.31 16.57

3 178.86 76.40 16.58

4 178.83 76.46 16.58

5 178.88 76.88 16.59

6 178.86 77.21 16.58

7 178.84 77.44 16.59

8 178.81 77.63 16.59

9 178.78 77.74 16.58

10 178.75 77.81 16.59

11 178.70 77.87 16.58

12 178.69 77.94 16.58

13 178.73 78.09 16.64

14 178.70 78.21 16.66

15 178.67 78.31 16.68

16 178.63 78.44 16.72

17 178.61 78.58 16.74

18 178.59 78.79 16.71

19 178.58 78.93 16.66

20 178.58 78.96 16.61

21 178.59 78.97 16.58

22 178.59 78.98 16.55

23 178.59 78.91 16.51

24 178.60 78.77 16.48

25 178.67 78.82 16.48

26 178.72 78.98 16.48

27 178.73 78.99 16.55

28 178.79 79.04 16.55

29 178.95 79.88 16.63

30 179.01 80.29 16.62

Mean 178.74 78.20 16.59

Maximum 179.01 80.29 16.74

Minimum 178.58 76.24 16.48

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

Table 9 45
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

December

1 179.09 79.59 16.45

2 179.19 79.21 16.29

3 179.24 79.56 16.24

4 179.28 79.85 16.22

5 179.30 79.32 16.20

6 179.34 78.61 16.18

7 179.42 78.32 16.21

8 179.61 78.94 16.28

9 179.69 79.48 16.27

10 179.77 79.04 16.29

11 179.94 78.92 16.35

12 180.03 78.87 16.34

13 180.09 78.52 16.36

14 180.13 78.43 16.35

15 180.18 78.22 16.28

16 180.20 77.86 16.24

17 180.24 77.54 16.20

18 180.27 77.48 16.21

19 180.30 77.70 16.25

20 180.36 77.98 16.30

21 180.39 78.13 16.33

22 180.41 78.14 16.37

23 180.46 77.95 16.34

24 180.68 78.87 16.33

25 180.77 79.94 16.25

26 180.83 80.38 16.19

27 180.91 80.19 16.19

28 180.95 79.63 16.14

29 180.94 78.46 16.13

30 180.92 78.13 16.12

31 180.87 78.15 16.15

Mean 180.12 78.76 16.26

Maximum 180.95 80.38 16.45

Minimum 179.09 77.48 16.12

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

January

1 180.85 78.31 16.18

2 180.82 78.51 16.19

3 180.80 78.63 16.20

4 180.85 78.86 16.28

5 180.86 78.82 16.30

6 180.89 78.62 16.33

7 180.93 78.58 16.31

8 180.94 78.47 16.27

9 180.94 78.31 16.23

10 180.91 78.10 16.17

11 180.88 78.34 16.10

12 180.88 78.47 16.07

13 180.89 78.28 16.07

14 180.99 78.63 16.13

15 181.17 80.28 16.31

16 181.23 80.77 16.38

17 181.24 80.65 16.34

18 181.23 80.49 16.26

19 181.21 80.25 16.16

20 181.18 80.01 16.17

21 181.15 79.70 16.17

22 181.12 79.24 16.16

23 181.17 78.83 16.31

24 181.14 78.33 16.29

25 181.09 77.99 16.22

26 181.06 78.24 16.19

27 181.03 78.50 16.20

28 180.99 78.63 16.17

29 180.94 78.68 16.15

30 180.89 78.59 16.14

31 180.85 78.09 16.13

Mean 181.00 78.91 16.21

Maximum 181.24 80.77 16.38

Minimum 180.80 77.99 16.07

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

46 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

February

1 180.80 77.85 16.07

2 180.76 77.68 16.02

3 180.71 77.74 15.99

4 180.70 77.92 15.93

5 180.66 78.16 15.92

6 180.62 78.38 15.97

7 180.58 78.50 16.02

8 180.56 78.20 16.08

9 180.55 77.82 16.13

10 180.64 77.86 16.24

11 180.73 78.67 16.24

12 180.76 79.07 16.22

13 180.77 78.75 16.23

14 180.76 78.38 16.18

15 180.84 78.35 16.19

16 180.94 78.83 16.20

17 181.04 79.27 16.19

18 181.10 79.56 16.18

19 181.11 79.42 16.16

20 181.12 78.99 16.16

21 181.15 78.42 16.17

22 181.17 77.95 16.21

23 181.16 77.98 16.20

24 181.16 78.01 16.16

25 181.18 77.97 16.12

26 181.17 77.87 16.09

27 181.15 77.76 16.07

28 181.14 77.74 16.04

Mean 180.89 78.33 16.12

Maximum 181.18 79.56 16.24

Minimum 180.55 77.68 15.92

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

March

1 181.19 77.79 16.08

2 181.22 77.75 16.08

3 181.23 77.94 16.05

4 181.25 77.86 16.02

5 181.27 77.81 15.98

6 181.29 77.94 15.94

7 181.30 77.80 15.92

8 181.37 77.85 15.97

9 181.48 78.20 16.07

10 181.52 78.38 16.07

11 181.54 78.11 16.07

12 181.61 77.78 16.15

13 181.69 77.53 16.22

14 181.72 77.26 16.23

15 181.75 76.97 16.23

16 181.77 76.71 16.23

17 181.80 76.47 16.24

18 181.84 76.23 16.23

19 181.86 76.02 16.23

20 181.89 75.84 16.21

21 181.93 75.74 16.21

22 181.96 75.71 16.21

23 182.00 75.77 16.20

24 182.06 75.96 16.24

25 182.10 76.28 16.26

26 182.12 76.61 16.25

27 182.14 76.93 16.24

28 182.24 77.48 16.28

29 182.56 79.99 16.27

30 182.66 80.98 16.13

31 182.64 80.50 15.97

Mean 181.77 77.43 16.14

Maximum 182.66 80.98 16.28

Minimum 181.19 75.71 15.92

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

Table 9 47
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

April

1 182.61 78.79 15.87

2 182.66 75.63 15.82

3 182.78 74.85 15.82

4 182.78 74.78 15.73

5 182.71 74.82 15.68

6 182.66 75.30 15.64

7 182.61 75.40 15.59

8 182.59 75.93 15.65

9 182.53 76.35 15.69

10 182.48 76.49 15.75

11 182.36 76.76 15.84

12 182.31 77.33 15.90

13 182.27 77.74 15.92

14 182.22 77.96 15.97

15 182.18 77.97 16.02

16 182.16 77.94 16.07

17 182.14 78.32 16.12

18 182.11 78.65 16.19

19 182.09 78.82 16.24

20 182.09 78.89 16.27

21 182.03 78.99 16.32

22 182.01 79.18 16.26

23 182.01 79.34 16.24

24 182.12 79.83 16.32

25 182.18 79.92 16.33

26 182.17 79.70 16.29

27 182.16 79.25 16.25

28 182.18 79.08 16.26

29 182.17 78.80 16.24

30 182.15 78.32 16.22

Mean 182.32 77.70 16.02

Maximum 182.78 79.92 16.33

Minimum 182.01 74.78 15.59

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

May

1 182.18 78.11 16.26

2 182.19 78.04 16.23

3 182.18 78.32 16.21

4 182.15 78.51 16.19

5 182.10 78.54 16.16

6 182.06 78.50 16.08

7 182.12 78.55 16.06

8 182.22 79.11 16.10

9 182.21 79.42 16.18

10 182.17 79.50 16.22

11 182.16 79.44 16.24

12 182.11 79.36 16.29

13 182.05 79.70 16.30

14 182.02 80.09 16.31

15 181.99 80.40 16.38

16 181.99 80.58 16.46

17 181.98 80.60 16.43

18 181.96 80.55 16.40

19 181.96 80.50 16.42

20 181.94 80.41 16.41

21 181.93 79.80 16.27

22 181.95 79.23 16.16

23 181.97 78.71 16.04

24 182.07 78.44 15.98

25 182.28 78.57 15.92

26 182.50 77.82 15.91

27 182.54 77.91 15.85

28 182.52 77.93 15.84

29 182.47 78.20 15.86

30 182.43 78.31 15.86

31 182.41 78.16 15.88

Mean 182.16 79.07 16.16

Maximum 182.54 80.60 16.46

Minimum 181.93 77.82 15.84

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

48 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

June

1 182.39 77.84 15.88

2 182.34 77.60 15.87

3 182.29 77.97 15.83

4 182.24 78.32 15.78

5 182.22 78.81 15.84

6 182.16 79.18 15.86

7 182.13 79.44 15.84

8 182.11 79.62 15.84

9 182.20 80.28 15.91

10 182.21 80.70 15.96

11 182.18 80.26 16.01

12 182.14 78.55 16.07

13 182.12 78.12 16.12

14 182.10 77.74 16.15

15 182.07 77.49 16.16

16 182.03 77.64 16.20

17 182.05 78.05 16.18

18 182.02 78.43 16.13

19 181.98 78.70 16.10

20 181.98 78.96 16.05

21 181.96 79.09 15.98

22 181.91 79.13 15.92

23 181.89 78.96 15.93

24 181.89 78.72 15.94

25 181.84 78.46 15.95

26 181.83 78.18 15.98

27 181.81 77.97 15.98

28 181.75 77.72 15.96

29 181.72 77.46 15.93

30 181.68 77.30 15.87

Mean 182.04 78.56 15.97

Maximum 182.39 80.70 16.20

Minimum 181.68 77.30 15.78

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

July

1 181.64 77.20 15.81

2 181.57 77.23 15.81

3 181.50 77.24 15.87

4 181.37 77.26 15.96

5 181.25 77.23 16.02

6 181.17 77.69 16.12

7 180.75 78.67 16.25

8 180.83 77.82 16.26

9 181.24 77.76 16.29

10 181.40 77.71 16.15

11 181.45 77.23 16.02

12 181.45 77.17 16.02

13 181.35 77.43 16.07

14 181.26 77.62 16.11

15 181.16 77.74 16.12

16 181.08 77.77 16.13

17 181.01 77.75 16.17

18 180.95 77.73 16.23

19 180.86 77.76 16.20

20 180.78 77.77 16.11

21 180.64 77.76 16.05

22 180.57 77.73 16.03

23 180.43 77.73 16.03

24 180.28 77.68 16.01

25 180.30 77.59 16.01

26 180.06 77.52 15.99

27 179.98 77.47 15.95

28 179.54 77.53 15.92

29 179.55 77.62 15.84

30 179.41 77.64 15.91

31 179.28 77.59 15.95

Mean 180.78 77.60 16.05

Maximum 181.64 78.67 16.29

Minimum 179.28 77.17 15.81

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

Table 9 49
Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

August

1 179.31 77.50 15.97

2 179.38 77.85 16.16

3 179.27 78.03 16.22

4 179.18 77.99 16.28

5 179.11 77.89 16.33

6 178.85 77.77 16.36

7 178.84 77.66 16.47

8 178.73 77.52 16.55

9 178.65 77.40 16.60

10 178.57 77.33 16.57

11 178.42 77.31 16.52

12 178.30 77.40 16.42

13 178.22 77.44 16.32

14 178.16 77.54 16.30

15 178.10 78.17 16.39

16 178.25 78.53 16.43

17 178.25 78.62 16.48

18 178.16 78.62 16.49

19 178.16 78.55 16.52

20 178.12 78.46 16.56

21 178.11 78.39 16.61

22 178.06 78.37 16.60

23 177.95 78.33 16.57

24 177.86 78.29 16.58

25 177.85 78.23 16.58

26 177.84 78.17 16.55

27 177.78 78.12 16.54

28 177.76 78.05 16.55

29 177.71 77.94 16.53

30 177.70 77.33 16.34

31 e177.71 76.58 16.05

Mean e178.33 77.92 16.43

Maximum 179.38 78.62 16.61

Minimum e177.70 76.58 15.97

Table 9. Daily, monthly, and annual statistics for reservoir altitude for U.S. Geological Survey station numbers 01104430, 

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond 

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in feet relative to the City of Cambridge datum. Add 10.34 feet to altitude to adjust to National Geodetic Vertical Datum of 1929. e, estimated]

Month and 

date

Cambridge 

Reservoir 

near Kendal Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

September

1 177.66 75.94 15.79

2 177.51 76.02 15.65

3 177.36 76.19 15.59

4 177.21 76.30 15.57

5 177.11 76.39 15.56

6 177.01 76.47 15.55

7 176.95 76.53 15.52

8 176.86 76.59 15.48

9 176.73 76.60 15.44

10 176.63 76.57 15.46

11 176.57 76.46 15.54

12 176.51 76.33 15.56

13 176.31 76.16 15.57

14 176.22 76.05 15.64

15 176.10 e75.79 15.72

16 175.98 e75.54 15.78

17 175.90 75.42 15.88

18 175.80 75.29 16.01

19 175.71 75.24 16.09

20 175.60 75.22 16.16

21 175.49 75.28 16.21

22 175.36 75.32 16.25

23 175.22 75.46 16.26

24 175.12 75.59 16.25

25 175.03 75.74 16.26

26 174.94 75.87 16.27

27 174.88 75.83 16.27

28 174.78 75.92 16.24

29 174.71 76.24 16.25

30 174.66 76.62 16.25

Mean 176.06 e75.97 15.87

Maximum 177.66 76.62 16.27

Minimum 174.66 e75.22 15.44

Annual mean 180.25 77.98 16.19

Annual 

maximum

182.78 80.98 16.74

Annual 

minimum

174.66 74.78 15.44

Gage 1181.34 280.30 317.0

Remarks Good4 Excellent4 Excellent 1

Reservoir spillway altitude prior to January 2005, 182.94 otherwise.

2

Reservoir spillway altitude.

3

Maximum reservoir elevation without causing localized flooding.

4

Records that are estimated are rated as fair.

50 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

October

1 1,970 241 1,533

2 1,974 236 1,533

3 1,982 231 1,533

4 1,987 231 1,532

5 1,995 232 1,531

6 2,003 231 1,529

7 2,011 230 1,526

8 2,012 232 1,514

9 2,009 234 1,505

10 2,002 236 1,503

11 1,996 236 1,504

12 2,004 234 1,503

13 2,010 231 1,501

14 2,013 227 1,500

15 2,012 225 1,502

16 2,031 229 1,508

17 2,037 232 1,510

18 2,039 233 1,511

19 2,053 233 1,514

20 2,068 234 1,517

21 2,076 233 1,519

22 2,084 232 1,520

23 2,091 230 1,521

24 2,095 227 1,525

25 2,091 225 1,525

26 2,088 224 1,526

27 2,087 222 1,527

28 2,085 221 1,529

29 2,084 219 1,530

30 2,084 218 1,530

31 2,078 219 1,530

Mean 2,037 230 1,519

Maximum 2,095 241 1,533

Minimum 1,970 218 1,500

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.

[Units are in millions of gallons. e, estimated]

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

November

1 2,066 220 1,529

2 2,058 220 1,528

3 2,052 221 1,528

4 2,046 222 1,528

5 2,055 226 1,529

6 2,051 229 1,528

7 2,047 231 1,529

8 2,042 233 1,529

9 2,036 234 1,528

10 2,030 234 1,529

11 2,023 235 1,528

12 2,021 236 1,528

13 2,027 237 1,531

14 2,023 238 1,532

15 2,016 239 1,533

16 2,011 240 1,535

17 2,006 242 1,536

18 2,002 244 1,535

19 2,001 245 1,532

20 2,001 245 1,530

21 2,004 245 1,528

22 2,002 246 1,527

23 2,002 245 1,525

24 2,005 243 1,523

25 2,018 244 1,523

26 2,025 245 1,523

27 2,028 246 1,527

28 2,038 246 1,526

29 2,068 254 1,531

30 2,078 258 1,530

Mean 2,029 238 1,529

Maximum 2,078 258 1,536

Minimum 2,001 220 1,523

Table 10 51
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

December

1 2,092 251 1,521

2 2,112 248 1,513

3 2,120 251 1,511

4 2,127 254 1,510

5 2,131 249 1,509

6 2,138 242 1,508

7 2,155 239 1,509

8 2,189 245 1,513

9 2,205 250 1,513

10 2,221 246 1,513

11 2,255 245 1,517

12 2,270 244 1,516

13 2,280 241 1,517

14 2,288 240 1,517

15 2,296 238 1,513

16 2,300 235 1,511

17 2,306 232 1,509

18 2,312 231 1,510

19 2,317 233 1,512

20 2,327 236 1,514

21 2,333 237 1,516

22 2,337 237 1,518

23 2,346 236 1,516

24 2,383 244 1,516

25 2,399 255 1,512

26 2,410 259 1,509

27 2,426 257 1,508

28 2,432 252 1,506

29 2,431 240 1,505

30 2,427 237 1,505

31 2,419 238 1,506

Mean 2,283 243 1,512

Maximum 2,432 259 1,521

Minimum 2,092 231 1,505

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

January

1 2,414 239 1,508

2 2,409 241 1,509

3 2,405 242 1,509

4 2,414 244 1,513

5 2,416 244 1,514

6 2,423 242 1,516

7 2,429 242 1,515

8 2,430 241 1,513

9 2,430 239 1,511

10 2,425 237 1,507

11 2,419 239 1,504

12 2,419 241 1,502

13 2,422 239 1,502

14 2,440 242 1,505

15 2,472 258 1,515

16 2,484 262 1,518

17 2,487 261 1,516

18 2,485 260 1,512

19 2,480 258 1,507

20 2,475 256 1,508

21 2,469 253 1,507

22 2,463 248 1,507

23 2,473 244 1,514

24 2,466 239 1,514

25 2,458 236 1,510

26 2,453 238 1,509

27 2,448 241 1,509

28 2,440 242 1,508

29 2,431 243 1,507

30 2,422 242 1,506

31 2,414 237 1,505

Mean 2,442 245 1,510

Maximum 2,487 262 1,518

Minimum 2,405 236 1,502

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated]

52 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

February

1 2,406 235 1,503

2 2,398 233 1,500

3 2,390 234 1,498

4 2,387 235 1,495

5 2,381 238 1,495

6 2,373 240 1,497

7 2,366 241 1,500

8 2,363 238 1,503

9 2,362 234 1,505

10 2,376 235 1,511

11 2,393 243 1,511

12 2,398 246 1,510

13 2,400 243 1,510

14 2,399 240 1,508

15 2,413 239 1,509

16 2,430 244 1,509

17 2,449 248 1,508

18 2,460 251 1,508

19 2,462 250 1,507

20 2,463 246 1,507

21 2,469 240 1,508

22 2,472 236 1,509

23 2,471 236 1,509

24 2,472 236 1,507

25 2,474 236 1,505

26 2,474 235 1,504

27 2,470 234 1,502

28 2,468 234 1,501

Mean 2,423 239 1,505

Maximum 2,474 251 1,511

Minimum 2,362 233 1,495

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

March

1 2,476 234 1,503

2 2,481 234 1,503

3 2,485 236 1,501

4 2,488 235 1,500

5 2,491 234 1,498

6 2,495 236 1,496

7 2,497 234 1,495

8 2,510 235 1,497

9 2,531 238 1,503

10 2,538 240 1,502

11 2,542 237 1,503

12 2,556 234 1,507

13 2,571 232 1,510

14 2,577 229 1,510

15 2,581 227 1,510

16 2,586 224 1,511

17 2,592 222 1,511

18 2,598 220 1,511

19 2,604 218 1,511

20 2,610 216 1,509

21 2,617 215 1,510

22 2,623 215 1,509

23 2,630 216 1,509

24 2,636 217 1,511

25 2,640 220 1,512

26 2,643 223 1,511

27 2,644 226 1,511

28 2,654 231 1,513

29 2,686 255 1,513

30 2,696 264 1,506

31 2,695 260 1,497

Mean 2,580 231 1,506

Maximum 2,696 264 1,513

Minimum 2,476 215 1,495

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated]

Table 10 53
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

April

1 2,691 244 1,492

2 2,696 214 1,490

3 2,708 205 1,490

4 2,708 204 1,485

5 2,701 205 1,483

6 2,696 212 1,481

7 2,691 212 1,478

8 2,689 217 1,481

9 2,683 221 1,483

10 2,678 222 1,486

11 2,666 225 1,491

12 2,661 230 1,494

13 2,657 234 1,495

14 2,652 236 1,497

15 2,648 236 1,500

16 2,646 236 1,502

17 2,644 239 1,505

18 2,641 242 1,509

19 2,639 244 1,511

20 2,639 245 1,513

21 2,632 246 1,515

22 2,631 247 1,512

23 2,632 249 1,511

24 2,643 254 1,515

25 2,648 255 1,515

26 2,647 253 1,514

27 2,647 248 1,511

28 2,648 246 1,512

29 2,647 244 1,511

30 2,645 239 1,510

Mean 2,662 233 1,500

Maximum 2,708 255 1,515

Minimum 2,631 204 1,478

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

May

1 2,648 237 1,512

2 2,649 236 1,511

3 2,648 239 1,509

4 2,645 241 1,508

5 2,640 241 1,507

6 2,636 241 1,503

7 2,642 241 1,502

8 2,652 247 1,504

9 2,651 250 1,508

10 2,647 251 1,510

11 2,647 250 1,511

12 2,641 249 1,513

13 2,635 253 1,514

14 2,632 256 1,515

15 2,628 259 1,518

16 2,628 261 1,522

17 2,626 261 1,521

18 2,622 260 1,519

19 2,623 260 1,520

20 2,618 259 1,520

21 2,617 254 1,513

22 2,622 248 1,507

23 2,624 243 1,501

24 2,637 240 1,498

25 2,658 242 1,495

26 2,680 234 1,494

27 2,684 235 1,491

28 2,682 235 1,491

29 2,677 238 1,492

30 2,673 239 1,492

31 2,671 238 1,493

Mean 2,645 246 1,507

Maximum 2,684 261 1,522

Minimum 2,617 234 1,491

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated]

54 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

June

1 2,669 235 1,493

2 2,664 232 1,492

3 2,659 236 1,490

4 2,654 239 1,488

5 2,652 244 1,491

6 2,647 247 1,491

7 2,644 250 1,491

8 2,641 252 1,491

9 2,651 258 1,494

10 2,651 262 1,497

11 2,648 258 1,499

12 2,644 241 1,502

13 2,642 237 1,505

14 2,640 234 1,506

15 2,637 231 1,507

16 2,633 233 1,509

17 2,635 237 1,508

18 2,632 240 1,506

19 2,626 243 1,504

20 2,626 245 1,502

21 2,623 247 1,498

22 2,614 247 1,495

23 2,610 245 1,495

24 2,610 243 1,496

25 2,600 240 1,497

26 2,598 238 1,498

27 2,593 236 1,498

28 2,583 233 1,497

29 2,575 231 1,495

30 2,569 230 1,492

Mean 2,629 241 1,498

Maximum 2,669 262 1,509

Minimum 2,569 230 1,488

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

July

1 2,560 229 1,489

2 2,547 229 1,489

3 2,535 229 1,492

4 2,510 229 1,497

5 2,488 229 1,500

6 2,472 233 1,505

7 2,396 243 1,512

8 2,410 234 1,512

9 2,485 234 1,514

10 2,516 233 1,507

11 2,524 229 1,500

12 2,525 228 1,500

13 2,507 231 1,502

14 2,489 233 1,504

15 2,471 234 1,505

16 2,457 234 1,505

17 2,443 234 1,507

18 2,433 234 1,511

19 2,416 234 1,509

20 2,402 234 1,505

21 2,377 234 1,501

22 2,364 234 1,500

23 2,339 234 1,500

24 2,314 233 1,499

25 2,317 232 1,499

26 2,277 232 1,498

27 2,261 231 1,496

28 2,177 232 1,495

29 2,178 233 1,491

30 2,153 233 1,494

31 2,129 232 1,496

Mean 2,402 232 1,501

Maximum 2,560 243 1,514

Minimum 2,129 228 1,489

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated]

Table 10 55
Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

August

1 2,133 231 1,497

2 2,146 235 1,507

3 2,127 236 1,510

4 2,110 236 1,513

5 2,096 235 1,515

6 2,049 234 1,517

7 2,047 233 1,523

8 2,027 232 1,527

9 2,013 230 1,529

10 1,999 230 1,527

11 1,974 230 1,525

12 1,952 231 1,520

13 1,940 231 1,515

14 1,929 232 1,514

15 1,919 238 1,518

16 1,944 241 1,521

17 1,944 242 1,523

18 1,928 242 1,524

19 1,929 241 1,525

20 1,921 241 1,527

21 1,921 240 1,530

22 1,912 240 1,529

23 1,894 239 1,528

24 1,878 239 1,528

25 1,877 238 1,528

26 1,875 238 1,527

27 1,866 237 1,526

28 1,862 237 1,527

29 1,855 236 1,526

30 1,852 230 1,516

31 e1,853 223 1,502

Mean 1,960 235 1,521

Maximum 2,146 242 1,530

Minimum 1,852 223 1,497

Month 

and date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

September

1 1,846 217 1,488

2 1,822 218 1,481

3 1,797 219 1,478

4 1,774 220 1,477

5 1,758 221 1,477

6 1,742 222 1,476

7 1,733 223 1,474

8 1,720 223 1,472

9 1,700 223 1,470

10 1,686 223 1,471

11 1,676 222 1,475

12 1,668 221 1,477

13 1,638 219 1,477

14 1,625 e217 1,480

15 1,607 e213 1,484

16 1,591 e212 1,488

17 1,580 e212 1,493

18 1,565 212 1,499

19 1,552 211 1,503

20 1,537 211 1,507

21 1,522 211 1,510

22 1,505 212 1,512

23 1,487 213 1,512

24 1,473 214 1,511

25 1,460 215 1,512

26 1,447 217 1,512

27 1,437 216 1,513

28 1,419 217 1,511

29 1,406 220 1,511

30 1,398 223 1,512

Mean 1,606 217 1,492

Maximum 1,846 223 1,513

Minimum 1,398 211 1,470

Annual mean 2,308 236 1,508

Annual 

maximum

2,708 264 1,536

Annual 

minimum

1,398 204 1,470

Remarks Excellent1 Excellent2 Excellent3

1

Reservoir storage capacity at spillway altitude is 2,503 million gallons prior to January 2005, otherwise storage capacity is 2,723 million gallons.

2

Reservoir storage capacity at spillway altitude is 258 million gallons.

3

Maximum reservoir storage capacity without causing localized flooding is 1,549 million gallons.

Table 10.  Daily, monthly, and annual statistics for reservoir capacity for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh Pond

Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in millions of gallons. e, estimated]

56 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey station numbers 01104430,

Cambridge Reservoir near Kendal Green, 01104480, Stony Brook Reservoir in Waltham, and 422302071083801, Fresh Pond

Reservoir at Cambridge, water year 2005.

[Units are in inches. e, estimated]

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

October

1 0.00 0.00 0.00

2 .17 .05 .05

3 .00 .00 .00

4 .00 .00 .00

5 .00 .00 .00

6 .00 .00 .00

7 .00 .00 .00

8 .00 .00 .00

9 .00 .00 .00

10 .00 .00 .00

11 .00 .00 .00

12 .07 .04 .08

13 .00 .00 .00

14 .04 .03 .02

15 .57 .50 .43

16 .53 .54 .54

17 .00 .00 .00

18 .00 .00 .00

19 .64 .59 .52

20 .00 .00 .00

21 .00 .00 .00

22 .02 .01 .01

23 .00 .00 .00

24 .00 .00 .00

25 .00 .00 .00

26 .00 .00 .00

27 .00 .00 .00

28 .00 .00 .00

29 .00 .00 .00

30 .45 .08 .04

31 .00 .00 .00

Total 2.49 1.84 1.69

Maximum .64 .59 .54

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

November

1 0.00 0.00 0.00

2 .01 .00 .01

3 .05 .03 .03

4 .68 .73 .76

5 .02 .01 .00

6 .00 .00 .00

7 .00 .00 .00

8 .00 .00 .00

9 .00 .00 .00

10 .00 .00 .00

11 .00 .00 .00

12 .02 .20 .10

13 .03 .13 .16

14 .20 .00 .05

15 .59 .00 .00

16 .10 .00 .00

17 .08 .00 .00

18 .00 .00 .00

19 .00 .00 .00

20 .15 .15 .08

21 .03 .03 .02

22 .00 .00 .00

23 .00 .00 .00

24 .26 .27 .26

25 .34 .29 .27

26 .00 .00 .00

27 .00 .00 .00

28 1.19 1.21 1.14

29 .00 .00 .00

30 .00 .00 .00

Total 3.75 3.05 2.88

Maximum 1.19 1.21 1.14

Table 11 57
Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

December

1 1.02 0.71 0.63

2 .00 .00 .00

3 .00 .00 .00

4 .00 .00 .00

5 .00 .00 .00

6 .00 .01 .00

7 1.31 1.02 1.20

8 .06 .03 .05

9 .00 .00 .00

10 .84 .76 .68

11 .10 .09 .09

12 .00 .00 .00

13 .01 .00 .00

14 .00 .00 .00

15 .00 .00 .00

16 .00 .00 .00

17 .00 .00 .00

18 .00 .00 .00

19 .06 .04 .02

20 .03 .06 .07

21 .00 .00 .00

22 .51 .00 .00

23 1.14 1.12 1.10

24 .00 .00 .00

25 .00 .00 .00

26 e.66 .27 .18

27 .00 .00 .01

28 .00 .00 .00

29 .00 .00 .00

30 .00 .00 .00

31 .00 .00 .00

Total e5.74 4.11 4.03

Maximum 1.31 1.12 1.20

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

January

1 0.00 0.00 0.00

2 .04 .03 .03

3 .22 .22 .19

4 .31 .30 .30

5 .02 .12 .10

6 e.90 .92 .84

7 .00 .00 .00

8 e.60 .60 .50

9 .00 .00 .03

10 .00 .00 .00

11 .01 .02 .00

12 e.50 .48 .34

13 .00 .00 .00

14 .63 .57 .51

15 .00 .00 .00

16 .00 .00 .00

17 .00 .00 .00

18 .01 .00 .00

19 .07 .08 .06

20 .00 .03 .02

21 .00 .00 .00

22 .49 .55 .08

23 .88 .20 .00

24 .12 .00 .00

25 .00 .00 .03

26 .34 .25 .17

27 .00 .00 .00

28 .00 .00 .00

29 .00 .00 .00

30 .00 .00 .00

31 .00 .00 .00

Total e5.14 4.37 3.20

Maximum e.90 .92 .84

Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh

Pond Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in inches; e, estimated]

58 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

February

1 0.00 0.00 0.00

2 .00 .00 .00

3 .65 .22 .22

4 .43 .03 .04

5 .00 .00 .00

6 .00 .00 .00

7 .00 .00 .00

8 .00 .00 .00

9 .02 .02 .00

10 1.01 .71 .76

11 .04 .00 .01

12 .00 .00 .00

13 .00 .00 .00

14 .07 .04 .02

15 .52 .50 .38

16 .28 .24 .18

17 .00 .00 .00

18 .00 .00 .00

19 .00 .00 .00

20 .00 .00 .00

21 .39 .34 .34

22 .00 .00 .00

23 .02 .01 .00

24 .03 .03 .01

25 .12 .02 .01

26 .00 .00 .00

27 .00 .00 .00

28 .24 .30 .06

Mean 3.82 2.46 2.03

Maximum 1.01 .71 .76

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

March

1 0.36 0.16 0.21

2 .00 .00 .00

3 .00 .00 .00

4 .00 .00 .00

5 .00 .00 .00

6 .00 .00 .00

7 .00 .00 .00

8 .85 .37 .44

9 .04 .00 .00

10 .00 .00 .00

11 .08 .05 .05

12 .99 .86 .89

13 .00 .00 .00

14 .00 .00 .00

15 .00 .00 .00

16 .00 .00 .00

17 .00 .00 .00

18 .00 .00 .00

19 .00 .00 .00

20 .00 .00 .00

21 .00 .00 .00

22 .34 .00 .00

23 .07 .06 .03

24 .30 .27 .18

25 .00 .00 .00

26 .00 .00 .00

27 .00 .00 .00

28 1.80 1.60 1.33

29 .40 .42 .43

30 .00 .00 .00

31 .00 .00 .00

Total 5.23 3.79 3.56

Maximum 1.80 1.60 1.33

Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh

Pond Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in inches; e, estimated]

Table 11 59
Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

April

1 0.01 0.02 0.02

2 .95 .98 .94

3 .62 .64 .62

4 .01 .00 .00

5 .00 .00 .00

6 .00 .00 .00

7 .00 .00 .00

8 .34 .37 .39

9 .00 .00 .00

10 .00 .00 .00

11 .00 .00 .00

12 .03 .01 .01

13 .00 .00 .00

14 .00 .00 .00

15 .00 .00 .00

16 .00 .00 .00

17 .00 .00 .00

18 .23 .00 .00

19 .00 .00 .00

20 .11 .06 .05

21 .17 .13 .15

22 .05 .03 .04

23 .47 .45 .42

24 .57 .61 .50

25 .18 .14 .17

26 .00 .00 .00

27 .52 .55 .62

28 .08 .06 .02

29 .00 .00 .00

30 .49 .45 .48

Total 4.83 4.50 4.43

Maximum .95 .98 .94

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

May

1 0.16 0.16 0.13

2 .07 .04 .03

3 .00 .01 .02

4 .00 .00 .00

5 .00 .00 .00

6 .00 .00 .00

7 .94 .72 .60

8 .04 .02 .02

9 .00 .00 .00

10 .00 .00 .00

11 .00 .00 .00

12 .20 .00 .00

13 .00 .00 .00

14 .00 .00 .00

15 .00 .00 .00

16 .62 .23 .27

17 .27 .00 .00

18 .01 .00 .17

19 .32 .03 .02

20 .00 .00 .00

21 .15 .11 .22

22 .22 .16 .07

23 .22 .18 .16

24 .90 .75 .97

25 1.14 1.23 .85

26 .61 .60 .59

27 .01 .00 .01

28 .06 .11 .17

29 .08 .05 .04

30 .01 .00 .00

31 .00 .00 .00

Total 6.03 4.40 4.34

Maximum 1.14 1.23 .97

Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh

Pond Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in inches; e, estimated]

60 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

June

1 0.00 0.00 0.00

2 .00 .00 .00

3 .00 .00 .00

4 .00 .00 .02

5 .00 .00 .00

6 .00 .00 .00

7 .00 .00 .01

8 .81 .79 .60

9 .21 .26 .21

10 .00 .00 .00

11 .00 .00 .00

12 .33 .00 .00

13 .00 .00 .00

14 .06 .01 .25

15 .02 .10 .18

16 .18 .26 .40

17 .04 .12 .06

18 .00 .00 .00

19 .00 .00 .00

20 .00 .00 .00

21 .00 .00 .00

22 .08 .06 .19

23 .00 .00 .00

24 .00 .00 .01

25 .00 .00 .00

26 .00 .00 .01

27 .00 .00 .00

28 .04 .03 .00

29 .02 .16 .03

30 .00 .00 .00

Total 1.79 1.79 1.97

Maximum .81 .79 .60

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

July

1 0.04 0.05 0.01

2 .00 .00 .01

3 .00 .00 .00

4 .00 .00 .00

5 .00 .00 .00

6 2.16 3.15 1.99

7 .01 .00 .00

8 1.54 1.42 1.06

9 .31 .21 .12

10 .01 .00 .00

11 .00 .00 .00

12 .00 .00 .00

13 .00 .00 .00

14 .00 .00 .00

15 .36 .00 .01

16 .00 .00 .00

17 .00 .00 .00

18 .00 .01 .16

19 .01 .01 .00

20 .00 .00 .04

21 .00 .00 .00

22 .40 .04 .58

23 .00 .00 .01

24 .00 .00 .00

25 .00 .00 .00

26 .00 .00 .01

27 .06 .03 .01

28 .00 .00 .01

29 .00 .00 .00

30 .00 .00 .00

31 .00 .00 .00

Total 4.90 4.92 4.02

Maximum 2.16 3.15 1.99

Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh

Pond Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in inches; e, estimated]

Table 11 61
Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

August

1 0.19 0.04 0.07

2 1.16 .90 1.34

3 .00 .00 .00

4 .00 .00 .00

5 .00 .12 .11

6 .00 .00 .00

7 .00 .00 .00

8 .00 .00 .00

9 .02 .01 .02

10 .00 .00 .00

11 .00 .00 .08

12 .02 .00 .00

13 .00 .00 .02

14 1.88 1.26 .64

15 .18 .33 .33

16 .00 .01 .00

17 .00 .00 .00

18 .00 .00 .00

19 .00 .00 .00

20 .00 .00 .00

21 .32 .13 .10

22 .00 .00 .00

23 .00 .00 .03

24 .01 .00 .00

25 .36 .00 .02

26 .00 .00 .00

27 .00 .00 .00

28 .00 .00 .00

29 .08 .19 .53

30 .15 .27 .19

31 .04 .09 .05

Total 4.41 3.35 3.53

Maximum 1.88 1.26 1.34

Month and 

date

Cambridge 

Reservoir 

near Kendal 

Green 

(01104430)

Stony Brook 

Reservoir 

at dam near 

Waltham 

(01104480)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

September

1 0.10 0.07 0.02

2 .00 .00 .00

3 .00 .00 .00

4 .02 .00 .00

5 .28 .00 .00

6 .00 .00 .00

7 .00 .00 .00

8 .30 .00 .00

9 .00 .00 .00

10 .00 .00 .01

11 .00 .00 .00

12 .00 .00 .01

13 .00 .00 .01

14 .00 .00 .00

15 .62 .91 .77

16 .10 .12 .10

17 .04 .02 .00

18 .01 .00 .01

19 .00 .00 .01

20 .03 .12 .02

21 .00 .00 .00

22 .00 .00 .00

23 .35 .00 .01

24 .00 .00 .00

25 .00 .00 .00

26 .15 .18 .16

27 .03 .05 .03

28 .00 .00 .00

29 .50 .53 .35

30 .12 .00 .00

Total 2.65 2.00 1.51

Maximum .62 .91 .77

Annual total 50.78 40.58 37.19

Annual 

maximum

2.16 3.15 1.99

Remarks Excellent1 Fair Excellent

1

Records that are estimated are rated as poor.

Table 11.  Daily, monthly, and annual statistics for precipitation for U.S. Geological Survey stations 01104430, Hobbs Brook

below Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in Waltham; and 422302071083801, Fresh

Pond Reservoir at Cambridge, Massachusetts, for water year 2005.—Continued

[Units are in inches; e, estimated]

62 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

October

1 20.8 11.5 15.2 21.6 11.4 15.3 22.6 12.6 16.2

2 19.2 11.9 15.0 19.6 11.6 14.8 20.1 12.4 15.7

3 16.6 6.9 12.7 17.1 7.4 12.8 17.0 8.6 13.6

4 19.3 5.0 11.9 19.8 4.9 12.5 20.4 6.8 13.9

5 13.9 2.9 9.8 14.3 2.9 9.9 15.4 5.5 11.0

6 16.1 .3 7.7 16.8 1.6 8.8 17.3 2.6 10.1

7 20.4 4.7 12.0 23.0 5.1 12.9 23.2 7.3 14.1

8 23.4 7.3 14.8 24.1 8.0 15.6 24.9 9.8 16.9

9 21.6 12.5 16.3 21.3 11.9 16.2 22.4 13.1 17.3

10 17.9 10.6 15.1 18.2 11.0 15.1 18.5 11.6 15.8

11 16.6 9.6 12.5 16.3 9.8 12.4 17.1 10.7 13.3

12 16.1 8.3 11.6 16.4 9.5 11.8 16.4 10.0 12.2

13 19.8 3.8 10.8 22.0 5.3 12.2 21.5 7.4 13.4

14 15.8 5.5 11.3 15.4 6.7 11.4 16.1 7.9 12.4

15 14.9 12.9 13.7 14.5 12.7 13.4 15.3 13.1 13.9

16 17.0 9.9 13.7 16.9 9.9 13.7 17.6 11.3 14.7

17 13.6 5.6 9.5 13.1 6.6 9.8 13.6 7.7 10.8

18 13.9 3.8 8.4 13.4 4.7 9.2 13.9 6.1 10.1

19 9.4 7.0 8.4 9.2 7.2 8.2 10.3 7.8 8.9

20 10.1 5.6 7.9 10.3 5.9 7.9 10.9 6.6 8.6

21 10.0 5.0 7.6 10.1 5.4 7.7 10.6 5.7 8.2

22 10.0 7.2 8.4 10.0 7.1 8.3 10.6 7.4 8.9

23 9.8 6.2 8.2 9.6 6.3 8.0 10.5 6.7 8.6

24 9.4 7.8 8.3 9.2 7.2 8.0 10.4 7.6 8.7

25 11.1 6.6 8.7 10.8 6.9 8.6 11.6 7.4 9.2

26 13.0 3.3 7.3 13.0 3.4 7.7 13.5 5.2 8.8

27 14.7 2.8 9.5 14.2 5.1 9.6 14.7 5.5 10.6

28 11.6 .0 6.0 12.1 1.4 6.5 11.9 2.8 7.5

29 14.5 .0 7.0 16.0 .9 7.5 14.9 2.8 8.8

30 15.6 4.2 10.1 15.5 4.7 9.9 16.0 5.8 10.9

31 21.1 12.2 16.5 19.7 13.1 16.6 20.2 13.3 70.0

Month 23.4 .0 10.8 24.1 .9 11.0 24.9 2.6 11.9

Table 12 63
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

November

1 14.8 3.5 11.0 14.0 5.4 11.2 14.6 5.8 11.4

2 11.3 1.0 7.3 11.6 2.2 7.8 12.5 3.4 8.8

3 12.4 2.1 9.1 12.6 2.0 9.2 13.1 3.1 9.2

4 9.2 –2.3 4.6 8.9 –1.4 4.7 10.0 .2 6.2

5 10.8 5.6 8.1 10.4 6.2 8.2 11.0 5.6 8.7

6 12.9 3.1 9.0 12.9 3.5 9.2 13.4 5.2 9.9

7 19.1 4.2 12.6 18.8 6.5 13.5 19.0 7.8 14.2

8 14.4 1.6 7.2 14.8 2.0 7.3 15.0 1.6 7.3

9 3.5 –3.9 –.1 3.4 –2.8 .2 3.9 –2.2 .8

10 4.4 –5.9 –.7 4.5 –5.5 –.3 4.6 –4.3 .8

11 14.2 1.1 7.4 14.0 1.0 8.1 14.3 3.1 9.0

12 5.8 –1.1 1.7 6.1 –1.1 1.8 5.9 –.9 2.2

13 4.6 –2.2 .0 5.1 –2.0 .2 5.2 –1.9 .7

14 8.2 –8.3 .1 8.7 –5.0 1.4 8.9 –4.1 2.5

15 12.9 –3.2 3.9 13.5 –3.1 4.5 13.4 .7 7.4

16 7.7 –1.5 2.8 8.0 .5 3.7 8.5 1.9 5.6

17 10.0 –1.6 3.7 10.6 –.6 4.5 10.6 .3 6.2

18 15.2 4.3 8.9 14.9 4.9 9.7 15.0 7.0 10.9

19 16.1 1.3 9.6 15.4 3.5 10.1 15.8 6.4 11.6

20 8.6 –1.1 4.4 9.0 .4 4.8 9.1 2.7 6.1

21 6.9 4.6 6.0 6.9 4.6 5.9 7.6 5.2 6.6

22 10.3 –.8 5.3 9.7 .8 6.3 10.4 2.6 7.6

23 11.4 –3.1 2.5 11.5 –1.4 4.3 12.2 .0 5.4

24 15.2 1.5 8.2 15.1 2.8 8.3 16.1 5.5 9.7

25 18.5 2.8 13.7 18.4 3.0 13.7 18.4 4.0 14.4

26 4.4 –4.0 .3 4.1 –2.0 1.0 4.7 –.3 2.1

27 9.7 –5.0 2.2 9.5 –3.7 3.1 10.3 –1.7 4.6

28 13.8 3.9 9.1 14.0 1.9 8.7 13.9 6.8 10.0

29 9.8 –.4 5.5 9.6 .5 5.8 10.1 2.8 6.7

30 8.7 .6 4.3 8.4 .5 4.7 9.1 2.6 5.8

Month 19.1 –8.3 5.6 18.8 –5.5 6.1 19.0 –4.3 7.1

64 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

December

1 13.9 3.7 8.8 13.9 4.7 8.9 14.7 6.6 9.7

2 8.4 –1.6 3.5 7.7 .2 4.7 8.2 2.4 5.6

3 7.9 –1.5 2.9 7.3 –.8 3.1 7.7 1.5 4.3

4 4.0 –3.5 .6 3.7 –2.2 1.1 4.5 –.7 1.9

5 10.2 –2.3 5.0 9.8 –1.8 5.2 10.0 –1.5 5.5

6 –1.2 –5.1 –3.0 –1.2 –4.8 –2.7 –.6 –4.2 –2.2

7 7.6 –2.7 2.6 7.6 –2.5 3.1 8.4 –1.6 4.8

8 11.3 1.2 5.6 10.9 1.2 6.0 11.3 2.0 6.5

9 5.6 –1.1 2.8 5.5 .4 3.6 6.6 2.3 4.8

10 7.0 3.9 5.6 6.9 4.0 5.5 7.5 5.5 6.2

11 7.0 3.0 5.1 7.0 3.5 5.3 7.7 4.0 6.1

12 5.9 1.3 3.5 6.2 1.6 3.9 7.1 2.8 4.6

13 8.7 1.6 4.3 8.2 1.7 4.5 8.5 2.8 5.4

14 1.8 –6.8 –2.3 2.4 –5.9 –1.9 2.8 –5.8 –1.4

15 –2.7 –9.3 –6.3 –2.6 –8.2 –5.9 –2.3 –7.7 –5.2

16 5.5 –10.1 –2.6 5.7 –9.7 –1.9 6.1 –7.4 –.7

17 5.8 –6.1 1.5 5.1 –4.4 1.8 5.5 –2.6 2.5

18 2.9 –9.3 –3.0 2.7 –8.3 –2.7 2.9 –6.0 –1.3

19 5.1 –3.1 .6 5.0 –3.5 .8 5.8 –2.0 2.0

20 1.5 –15.2 –8.4 1.2 –14.7 –8.1 3.0 –13.8 –7.3

21 –1.5 –16.4 –9.4 –.9 –15.6 –8.3 –.4 –14.8 –7.3

22 8.0 –9.8 –1.1 8.8 –8.0 1.1 9.8 –4.9 2.9

23 16.7 1.0 9.9 16.6 1.8 9.9 17.1 3.3 11.4

24 10.6 –2.9 .7 10.7 –2.4 .9 11.4 –2.0 1.4

25 –.6 –8.1 –3.8 –.8 –7.3 –3.6 .0 –5.5 –2.6

26 –4.3 –6.4 –5.2 –4.1 –6.0 –4.9 –3.0 –5.9 –4.4

27 –4.4 –12.8 –7.5 –4.0 –11.1 –6.8 –3.4 –10.4 –6.4

28 –2.3 –16.5 –7.3 –2.3 –13.0 –6.6 –2.1 –12.4 –6.1

29 5.1 –2.7 .5 4.8 –2.5 .9 5.1 –2.1 1.5

30 3.4 –6.3 –.7 3.6 –4.7 .0 4.5 –2.2 1.1

31 8.2 –6.4 2.6 8.3 –5.0 2.9 8.8 –3.0 4.5

Month 16.7 –16.5 .2 16.6 –15.6 .6 17.1 –14.8 1.5

Table 12 65
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

January

1 11.0 –0.3 5.8 11.1 0.9 6.5 11.4 1.5 7.2

2 3.0 –2.9 .0 3.3 –2.3 .3 4.5 –2.3 .7

3 11.8 3.0 7.9 11.4 3.3 8.3 11.6 4.5 8.9

4 7.0 1.0 4.7 6.9 2.6 5.2 7.6 3.6 5.5

5 1.7 –3.0 –.6 2.7 –2.7 –.3 3.7 –2.3 .3

6 2.0 –4.8 –1.6 2.0 –4.7 –1.5 3.1 –4.3 –.6

7 3.7 –4.8 .1 3.4 –3.4 .6 3.8 –1.5 1.3

8 –.2 –4.8 –1.7 –.3 –3.1 –1.5 1.1 –1.8 –.6

9 .0 –7.0 –2.4 –.2 –5.1 –2.2 .3 –4.1 –1.4

10 4.2 –1.2 1.4 3.9 –1.2 1.5 4.4 –.5 2.1

11 1.2 –3.6 –.6 2.0 –2.5 –.4 1.9 –1.2 .4

12 2.8 –1.7 .9 2.8 –1.9 .9 3.4 –.8 1.7

13 13.4 –.6 3.3 14.0 –.8 3.3 14.8 –.6 3.9

14 16.7 –.2 8.1 16.9 .0 8.3 18.1 .3 9.0

15 –.2 –5.7 –3.0 .0 –5.3 –2.8 .3 –4.1 –2.1

16 –2.4 –7.3 –4.7 –2.3 –6.6 –4.6 –1.5 –5.8 –3.9

17 –4.4 –11.5 –7.0 –4.6 –11.0 –6.7 –3.9 –10.8 –6.4

18 –11.0 –16.8 –13.8 –10.4 –16.2 –13.2 –10.4 –15.0 –12.7

19 –4.4 –18.2 –10.7 –4.6 –17.6 –10.5 –3.5 –16.2 –9.6

20 –2.1 –10.0 –6.3 –2.9 –9.6 –6.3 –2.3 –9.9 –5.8

21 –10.0 –18.1 –14.8 –9.6 –17.5 –14.5 –9.9 –16.6 –13.9

22 –4.3 –21.0 –14.0 –3.9 –20.1 –13.5 –3.3 –19.1 –12.5

23 –4.4 –15.9 –11.7 –4.2 –15.4 –11.1 –3.7 –15.0 –10.7

24 –4.5 –20.3 –11.9 –5.0 –17.0 –11.0 –4.4 –15.2 –10.1

25 –3.2 –13.3 –6.9 –3.5 –9.3 –6.4 –3.0 –8.8 –6.1

26 –5.9 –9.5 –7.6 –5.5 –9.3 –7.4 –4.8 –9.3 –6.9

27 –9.2 –15.6 –12.0 –9.1 –15.3 –11.8 –8.6 –14.9 –11.5

28 –6.1 –17.8 –12.9 –5.8 –18.0 –13.0 –5.8 –16.8 –11.4

29 3.0 –19.8 –8.4 2.9 –20.4 –8.0 2.7 –16.4 –6.1

30 3.2 –9.6 –2.5 4.5 –5.7 –1.8 4.2 –5.4 –.9

31 –1.5 –13.5 –6.0 –1.1 –13.1 –5.3 –1.2 –11.2 –5.0

Month 16.7 –21.0 –4.2 16.9 –20.4 –3.8 18.1 –19.1 –3.1

66 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

February

1 3.0 –16.0 –7.6 4.4 –16.4 –6.7 3.8 –13.7 –5.9

2 2.7 –14.5 –5.5 3.8 –13.8 –4.8 3.4 –12.1 –3.9

3 3.4 –9.4 –2.1 4.0 –7.8 –1.7 3.7 –5.8 –.9

4 2.1 –3.1 .5 2.0 –2.5 .6 2.6 –2.2 1.0

5 11.5 –5.0 1.8 12.0 –4.8 2.2 12.7 –1.9 3.5

6 6.6 –4.6 .7 8.2 –3.6 1.5 7.1 –3.5 2.3

7 11.2 –6.5 .4 11.6 –5.6 1.5 12.1 –5.0 2.0

8 10.0 –3.7 2.0 11.2 –3.2 3.3 11.5 –1.4 5.2

9 10.2 –1.4 4.3 11.1 –.8 5.0 11.0 1.1 6.5

10 4.0 .0 2.5 4.2 –.3 2.3 5.7 .6 3.0

11 .0 –4.7 –2.6 –.1 –4.7 –2.4 .8 –3.5 –1.6

12 4.1 –7.2 –1.6 3.1 –4.5 –1.0 3.9 –3.1 .1

13 2.7 –5.3 –1.4 2.4 –5.1 –1.5 2.7 –4.5 –.6

14 4.2 –9.3 –1.6 3.9 –8.7 –1.6 4.8 –7.0 –.5

15 10.4 –.3 5.8 10.2 .9 6.2 10.5 2.5 7.3

16 12.7 –1.1 5.1 12.4 –1.0 5.1 13.0 .9 6.6

17 3.9 –2.4 .9 3.7 –2.4 .9 4.3 –1.0 1.6

18 1.1 –8.3 –3.2 –.4 –8.3 –3.4 .2 –7.1 –2.7

19 –2.5 –11.4 –7.4 –2.8 –11.4 –7.5 –2.5 –10.8 –6.6

20 –.9 –7.8 –4.5 –1.2 –8.0 –4.7 –1.0 –6.4 –4.0

21 –.4 –6.2 –2.8 –.5 –5.3 –2.8 .5 –4.9 –2.0

22 –.1 –5.6 –3.0 .0 –5.4 –3.0 .1 –5.2 –2.6

23 2.3 –5.4 –1.4 2.0 –5.9 –1.3 2.2 –4.6 –.5

24 –2.8 –10.9 –6.5 –3.2 –11.2 –6.5 –3.5 –9.8 –5.9

25 –1.9 –11.4 –5.7 –2.4 –9.1 –5.5 –1.3 –7.5 –4.8

26 1.1 –17.1 –6.3 .5 –16.0 –5.8 1.3 –10.5 –3.7

27 1.0 –9.8 –4.6 .6 –8.4 –4.2 .9 –7.2 –3.0

28 1.1 –11.4 –3.8 1.2 –10.4 –3.7 1.6 –6.8 –2.0

Month 12.7 –17.1 –1.7 12.4 –16.4 –1.4 13.0 –13.7 –.4

Table 12 67
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

March

1 –1.0 –4.3 –2.4 –0.9 –4.3 –2.4 –0.5 –3.7 –1.7

2 1.2 –5.7 –2.7 .8 –5.0 –2.4 1.1 –4.4 –1.9

3 –1.6 –8.8 –5.0 –2.0 –7.5 –4.9 –1.6 –6.6 –4.2

4 1.2 –14.4 –5.9 .0 –14.9 –5.4 .6 –8.8 –3.8

5 5.4 –11.0 –2.5 5.2 –7.0 –.8 5.3 –5.9 –.3

6 6.1 –7.7 .5 5.8 –5.5 1.3 5.9 –2.7 2.0

7 9.8 –.7 5.5 9.7 1.8 6.0 10.2 2.5 6.5

8 7.1 –9.8 .6 7.2 –9.6 .9 8.1 –8.5 1.8

9 –5.1 –12.8 –8.7 –5.6 –12.6 –8.6 –4.9 –11.6 –7.8

10 –.7 –16.4 –8.4 –1.2 –14.1 –7.3 –.8 –10.3 –5.6

11 1.1 –12.7 –4.0 .5 –11.2 –3.9 1.4 –7.9 –2.1

12 .7 –1.2 .3 .7 –1.3 .1 1.5 –.6 .7

13 4.2 –5.3 –.3 4.2 –5.2 –.1 4.3 –2.5 .6

14 5.1 –4.7 .3 4.3 –4.5 .1 4.8 –3.5 .9

15 7.3 –2.3 2.1 7.1 –2.2 2.0 7.4 –1.1 2.7

16 6.5 –2.8 1.8 6.0 –2.2 1.9 6.5 –.5 2.8

17 7.5 –6.5 .4 7.3 –6.4 .6 7.4 –2.6 2.0

18 6.5 –4.6 1.2 6.1 –4.2 1.0 6.6 –2.5 2.2

19 8.6 –4.2 1.6 8.0 –2.6 1.9 8.7 –1.4 3.3

20 10.6 –5.5 2.9 9.2 –5.3 2.7 9.9 –1.9 4.6

21 6.2 –2.9 2.6 6.9 –2.1 2.9 6.3 –.6 3.7

22 12.4 –3.3 4.0 11.8 –2.8 4.9 12.3 –1.2 6.4

23 6.0 –1.4 2.7 6.3 –1.0 2.8 7.1 .8 4.0

24 4.6 –2.4 1.0 4.6 –2.1 1.3 5.5 –1.1 2.0

25 9.5 –2.4 4.3 8.4 –2.2 3.7 8.8 –.2 4.7

26 5.6 –2.9 1.3 5.6 –2.1 1.3 4.9 –1.6 1.8

27 11.6 –4.1 3.8 11.2 –4.5 3.5 11.5 –2.0 4.7

28 5.4 .9 3.5 5.6 1.1 3.6 6.3 2.3 4.3

29 10.3 3.6 6.7 10.7 3.4 6.3 11.0 4.2 7.5

30 13.2 .7 6.5 12.6 1.0 6.1 11.4 2.1 7.0

31 10.0 –.3 5.0 9.6 –.6 5.0 9.4 1.2 5.7

Month 13.2 –16.4 .60 12.6 –14.9 .8 12.3 –11.6 1.8

68 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

April

1 13.7 3.2 7.2 13.0 3.4 7.3 11.2 4.0 7.4

2 10.2 3.0 5.9 10.7 3.1 6.0 10.5 3.4 6.3

3 12.5 5.4 9.2 12.2 5.4 9.2 12.7 6.5 10.0

4 11.6 3.5 6.8 10.6 3.6 6.7 11.0 4.5 7.3

5 17.1 .2 9.0 16.4 1.1 9.0 16.9 3.2 9.7

6 19.8 2.8 11.1 19.7 4.4 11.5 17.6 6.0 11.7

7 20.0 6.3 13.2 21.3 7.3 13.4 19.1 8.0 12.6

8 15.2 6.6 10.7 16.2 6.1 10.8 14.2 7.4 11.2

9 14.9 2.7 9.0 14.5 3.5 8.7 12.8 5.3 9.1

10 21.1 .1 11.6 20.7 1.0 11.6 21.2 3.1 12.6

11 11.8 3.7 6.9 11.9 4.2 6.6 13.4 4.8 7.0

12 10.3 –.8 3.6 9.7 –.3 3.2 9.4 .3 3.8

13 10.9 –1.6 4.3 11.7 –.3 4.6 10.7 .5 5.0

14 13.0 .4 7.2 11.8 1.5 7.0 11.8 4.1 7.8

15 11.2 –.6 5.7 9.5 .8 5.8 10.4 1.9 6.2

16 14.2 –2.3 6.3 13.4 –1.2 6.6 13.0 .9 7.4

17 23.9 –.9 11.7 23.9 .2 12.1 24.5 2.9 12.7

18 21.4 6.2 14.1 21.0 8.1 14.4 21.4 11.2 16.1

19 25.3 2.0 14.7 25.4 4.0 15.5 25.4 6.6 16.6

20 30.3 10.4 20.9 29.0 11.0 21.7 29.9 11.5 22.0

21 14.4 3.9 10.1 14.2 5.2 9.7 14.4 5.9 10.4

22 17.0 –.7 8.7 16.5 .9 8.9 16.3 3.3 9.9

23 14.9 5.8 10.6 15.8 6.4 11.0 16.8 6.9 11.8

24 17.0 5.1 13.2 16.2 6.0 13.1 16.8 7.7 13.7

25 10.9 3.5 7.4 11.2 4.9 7.8 10.9 5.3 8.5

26 20.9 1.4 11.7 20.3 2.8 12.2 21.1 5.3 13.2

27 12.5 9.6 11.3 12.5 9.8 11.3 13.6 9.6 11.5

28 15.9 7.9 11.1 15.1 8.0 11.0 15.7 8.4 11.4

29 17.6 3.6 11.3 17.6 5.3 11.2 18.1 5.9 11.8

30 13.6 8.1 11.6 13.4 8.5 11.5 14.3 9.5 12.2

Month 30.3 –2.3 9.9 29.0 –1.2 10.0 29.9 .3 10.6

Table 12 69
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

May

1 14.2 6.6 12.3 14.1 8.8 12.6 14.7 9.5 13.4

2 17.4 3.1 10.5 16.6 5.8 11.1 17.2 6.2 11.8

3 15.1 3.8 9.4 13.8 4.6 9.5 14.3 5.6 10.3

4 14.7 2.6 9.8 13.3 4.5 10.0 13.7 6.0 10.9

5 15.7 .6 9.3 14.5 3.0 9.6 14.7 3.8 10.5

6 13.2 2.6 8.8 12.8 3.3 8.8 13.1 5.3 9.6

7 9.8 5.6 7.0 9.3 5.5 6.6 9.7 5.9 7.1

8 10.4 6.0 8.3 10.1 5.8 8.0 10.5 5.9 8.3

9 14.1 8.3 10.4 13.6 7.9 10.0 13.6 8.3 10.2

10 19.6 9.6 13.5 18.7 9.7 13.3 19.5 10.5 13.8

11 26.5 8.0 16.7 25.0 7.9 16.1 26.6 9.7 17.2

12 16.7 7.0 13.1 16.0 7.9 12.8 17.6 8.8 13.6

13 17.9 –.1 10.1 17.7 2.2 9.9 17.8 3.8 11.1

14 19.3 6.9 13.4 18.8 7.6 13.2 18.4 9.6 13.9

15 16.3 7.1 12.0 15.6 7.1 11.8 15.9 7.3 11.5

16 15.4 6.4 9.7 15.6 6.3 9.5 14.5 6.6 9.6

17 18.6 9.5 13.1 17.9 9.6 12.8 18.2 10.3 13.0

18 15.5 8.6 10.8 14.7 9.0 10.8 15.5 9.0 10.5

19 17.3 6.3 11.9 17.7 7.3 11.9 17.6 7.9 12.6

20 20.1 6.3 13.3 19.4 7.1 13.1 19.7 8.7 14.2

21 12.9 7.5 9.9 12.8 7.5 9.6 12.5 8.5 10.1

22 12.8 7.4 9.9 12.6 7.6 9.8 13.2 8.0 10.2

23 11.1 7.5 9.1 10.8 7.6 8.8 11.4 7.8 9.2

24 8.8 6.9 7.8 8.3 6.5 7.3 8.7 6.9 7.8

25 10.2 6.6 8.1 9.5 6.0 7.4 9.9 6.6 7.9

26 11.6 8.8 10.0 11.3 8.0 9.5 12.1 8.2 9.9

27 18.7 10.7 13.9 18.1 10.6 13.6 18.1 11.0 14.0

28 25.4 10.9 17.7 24.9 10.4 17.6 25.9 12.1 18.7

29 22.8 12.9 15.9 21.7 12.4 15.4 22.0 13.4 15.9

30 22.9 11.7 16.1 21.8 11.6 15.8 22.5 12.6 16.6

31 14.2 11.1 12.8 14.1 10.8 12.4 14.5 11.1 12.7

Month 26.5 –.1 11.4 25.0 2.2 11.2 26.6 3.8 11.8

70 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

June

1 18.8 9.2 13.7 18.5 9.2 13.6 17.8 10.3 13.9

2 25.2 10.5 16.9 24.4 10.3 16.4 25.6 10.9 17.2

3 25.4 10.6 18.1 24.9 10.6 18.0 26.1 11.2 18.7

4 29.1 14.2 21.6 29.5 14.4 21.7 29.7 15.8 22.5

5 31.2 15.6 23.7 30.7 15.9 23.5 31.0 16.9 24.5

6 22.6 12.4 16.2 22.6 11.9 15.9 21.2 12.3 15.7

7 29.8 17.3 23.4 30.3 18.0 24.1 31.1 19.4 25.0

8 30.4 14.8 23.2 31.9 15.7 23.7 32.3 18.7 25.2

9 26.1 17.5 21.8 25.7 17.8 21.7 25.3 18.9 21.8

10 28.3 17.1 23.2 27.6 17.2 23.3 28.6 18.0 24.4

11 30.8 20.8 25.4 31.4 20.7 25.6 32.5 21.3 26.5

12 29.9 21.1 25.3 30.3 21.0 25.5 31.8 22.0 26.5

13 31.4 22.5 26.3 31.9 22.7 26.7 31.8 23.8 27.6

14 26.0 12.6 19.6 25.7 12.7 20.0 26.5 12.5 20.1

15 12.9 9.9 10.9 12.8 9.4 10.4 13.4 9.9 10.9

16 16.7 9.7 12.6 16.4 9.7 12.2 15.9 10.0 12.4

17 22.4 10.9 15.0 22.1 10.8 14.5 22.8 11.0 14.5

18 19.9 13.1 15.3 19.9 12.5 14.8 19.0 12.5 14.9

19 17.2 10.0 14.3 18.4 10.1 14.1 17.8 11.9 14.6

20 25.0 8.2 17.3 26.0 9.1 17.1 25.5 9.8 17.9

21 27.8 12.1 20.3 27.8 11.5 20.7 28.7 13.2 21.7

22 22.0 16.4 19.0 22.4 15.9 19.2 23.3 17.4 20.0

23 23.6 9.6 18.1 24.4 11.1 18.0 24.7 12.5 19.0

24 28.7 12.5 21.7 29.0 13.3 22.1 29.9 15.5 23.1

25 32.9 17.9 25.2 32.6 18.6 26.0 34.0 19.5 27.0

26 33.6 20.2 26.6 34.1 20.3 26.7 35.4 22.3 27.9

27 31.3 19.6 25.2 30.8 20.5 25.3 29.5 22.4 25.4

28 26.4 22.5 23.9 26.4 22.5 23.9 28.4 23.8 25.1

29 29.0 21.2 23.9 29.0 21.0 23.9 29.6 22.5 25.0

30 27.6 18.5 23.0 26.1 18.5 22.5 26.9 18.4 23.4

Month 33.6 8.2 20.4 34.1 9.1 20.4 35.4 9.8 21.1

Table 12 71
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

July

1 24.9 16.9 20.3 24.8 16.6 20.0 24.6 16.9 20.2

2 26.6 17.7 22.9 25.4 17.8 22.6 26.2 20.7 23.8

3 25.7 12.4 20.1 25.6 13.0 20.1 25.9 14.8 21.2

4 27.5 12.3 19.7 27.0 13.0 20.4 26.3 15.0 21.1

5 29.4 13.1 22.2 29.1 13.8 22.5 30.6 16.0 23.7

6 22.8 16.2 19.8 22.7 15.6 19.5 23.3 16.0 20.2

7 18.5 15.4 16.9 18.6 15.0 16.4 18.4 15.9 17.0

8 16.7 13.5 15.5 16.4 12.9 14.9 17.0 13.4 15.4

9 24.4 13.0 17.6 24.3 12.9 17.3 25.7 13.4 18.1

10 30.5 16.4 23.0 30.0 17.0 23.2 31.2 17.8 24.3

11 31.7 20.1 26.4 30.4 21.2 26.1 31.7 21.6 27.5

12 24.9 17.2 21.2 24.0 17.1 20.8 23.6 18.0 21.1

13 25.5 16.0 21.0 25.3 15.9 20.7 26.5 17.1 21.9

14 28.2 18.6 23.4 28.4 18.6 23.4 29.8 19.8 24.6

15 28.6 19.6 24.0 28.0 19.9 23.8 28.6 22.1 24.7

16 28.5 18.4 23.3 29.0 18.7 23.4 31.4 20.3 25.3

17 27.5 20.2 23.3 27.3 20.7 23.7 30.2 21.7 25.1

18 29.0 21.9 24.6 29.5 23.1 25.2 30.7 24.2 26.3

19 31.6 21.7 25.8 32.2 23.2 26.6 33.3 24.5 28.0

20 30.9 20.1 25.6 30.2 21.5 25.9 31.2 23.0 27.5

21 29.1 18.3 23.8 29.2 19.1 24.3 30.5 22.0 26.0

22 31.3 18.3 25.0 31.9 18.8 25.4 32.5 20.9 26.9

23 27.1 17.7 22.8 26.5 19.0 22.6 27.2 20.4 23.7

24 26.8 14.9 20.9 28.0 16.1 21.5 28.1 18.3 22.7

25 27.2 17.4 22.9 28.8 19.2 23.9 29.3 21.0 25.1

26 31.4 18.4 25.0 33.0 19.1 26.5 34.0 21.3 27.9

27 33.3 20.6 27.0 33.4 20.8 27.6 35.2 21.8 28.9

28 23.9 14.5 20.4 23.6 15.6 20.6 23.6 18.0 21.2

29 26.6 12.7 20.2 27.7 13.5 21.3 28.1 15.7 22.5

30 26.6 17.5 21.4 26.4 18.5 21.8 26.2 19.7 22.4

31 21.5 16.6 19.4 21.6 17.3 19.5 21.7 19.1 20.3

Month 33.3 12.3 22.1 33.4 12.9 22.3 35.2 13.4 23.4

72 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

August

1 27.2 18.0 21.5 27.7 18.2 22.2 29.1 18.9 23.1

2 29.5 18.7 23.7 29.8 18.2 23.9 30.3 19.0 25.0

3 30.1 18.7 24.3 29.6 20.6 24.8 29.2 21.9 25.4

4 28.9 18.9 24.0 28.9 19.0 23.9 28.1 20.7 24.4

5 32.3 21.1 25.3 32.7 21.0 25.1 34.5 22.2 26.2

6 27.6 17.3 23.0 28.5 18.3 22.8 27.6 20.5 24.0

7 28.4 16.1 22.3 29.0 16.2 23.0 30.2 18.1 24.2

8 31.6 18.1 24.7 32.0 18.5 24.7 32.8 19.9 26.0

9 29.0 21.1 24.4 29.1 21.3 24.7 30.7 22.8 25.9

10 30.6 20.1 24.8 30.6 20.5 25.2 32.3 22.0 26.4

11 31.0 20.6 25.5 30.7 20.5 25.3 31.7 22.1 26.0

12 29.2 21.4 24.7 28.7 21.4 24.9 28.2 22.1 25.2

13 32.6 22.8 27.3 32.8 23.7 27.8 33.7 25.2 28.9

14 32.0 19.1 24.5 31.2 19.3 24.3 31.9 19.9 25.3

15 20.4 16.0 19.1 20.2 16.3 18.7 20.9 17.7 19.4

16 24.5 14.2 19.7 24.7 14.0 19.5 24.2 15.4 20.0

17 28.4 17.7 22.7 27.0 17.2 22.3 27.8 19.0 23.6

18 24.2 15.1 19.8 24.7 15.2 19.8 25.9 16.4 21.1

19 25.3 14.3 19.8 24.9 14.6 19.9 24.4 16.5 20.7

20 26.1 18.9 22.2 25.9 18.6 22.1 25.8 19.3 22.1

21 29.7 20.2 23.9 29.7 20.9 24.5 31.7 21.8 25.7

22 28.2 18.0 22.5 27.7 18.0 23.1 28.2 20.6 24.4

23 25.6 14.9 19.7 24.7 15.6 19.9 25.4 17.2 21.2

24 24.0 15.6 19.3 22.8 16.0 19.1 24.1 17.3 20.3

25 25.3 14.4 19.3 25.3 14.2 19.2 25.9 15.7 20.1

26 27.3 13.1 19.8 28.9 13.9 20.7 29.9 16.0 22.1

27 27.5 14.0 20.9 27.8 14.4 21.4 29.2 17.0 23.0

28 28.1 17.5 22.2 28.0 17.1 22.8 29.9 19.5 24.5

29 28.9 21.9 24.0 29.3 21.4 23.9 30.8 21.9 25.0

30 23.1 21.6 22.2 22.9 21.1 21.8 23.5 21.9 22.7

31 27.3 22.2 24.6 26.9 21.9 24.3 28.2 23.0 25.6

Month 32.6 13.1 22.6 32.8 13.9 22.8 34.5 15.4 23.8

Table 12 73
Table 12.  Daily, monthly, and annual statistics for air temperature for U.S. Geological Survey

stations 01104430, Cambridge Reservoir near Kendal Green; 01104480, Stony Brook Reservoir in

Waltham; and 422302071083801, Fresh Pond Reservoir at Cambridge, Massachusetts, for water year

2005.—Continued

[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated]

Month 

and 

date

Cambridge Reservoir 

near Kendal Green 

(01104430)

Stony Brook Reservoir at

 dam near Waltham 

(01104480)

Fresh Pond gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean

September

1 27.8 18.3 22.7 27.1 19.2 23.0 27.9 20.4 24.0

2 28.0 15.9 21.7 28.4 15.9 22.3 28.9 17.7 23.7

3 26.2 15.9 21.0 25.7 17.2 21.3 26.5 19.1 22.6

4 25.9 15.0 19.4 24.6 14.8 19.3 24.7 17.4 20.6

5 23.1 12.1 17.7 23.0 12.5 17.7 23.2 15.2 18.9

6 25.0 11.0 17.8 24.6 12.0 18.0 25.2 12.6 19.0

7 27.4 12.3 19.7 28.8 12.5 20.2 29.7 14.6 21.4

8 28.0 13.8 21.1 28.9 14.1 21.5 30.1 15.9 22.8

9 23.7 15.0 19.6 23.4 16.1 19.8 23.5 17.9 20.7

10 21.4 11.0 16.3 21.6 11.4 16.4 22.0 13.5 17.6

11 22.5 8.4 16.1 23.8 9.2 16.2 24.8 11.3 17.8

12 30.7 16.0 22.8 30.7 16.1 23.4 31.4 17.3 24.2

13 29.0 18.4 22.9 27.8 18.6 22.9 26.9 19.8 23.2

14 29.4 19.3 23.7 30.4 19.2 23.8 31.2 20.0 24.7

15 23.6 21.0 22.1 23.7 20.0 21.9 24.6 20.7 22.8

16 21.4 18.0 19.9 21.0 17.6 19.3 22.0 18.1 20.0

17 21.3 17.2 18.8 20.8 16.8 18.3 21.0 17.4 18.9

18 23.6 15.2 19.7 23.3 15.6 19.5 23.6 17.2 20.5

19 26.1 13.7 19.0 26.8 13.4 19.5 28.0 14.9 21.1

20 24.1 15.2 20.0 24.0 15.3 20.0 24.8 17.6 21.5

21 24.9 13.3 19.2 25.4 15.6 19.9 26.5 17.2 21.2

22 27.8 13.3 20.8 28.2 13.5 21.3 29.4 15.3 22.5

23 25.9 15.4 20.6 24.9 15.8 20.6 26.3 16.7 21.5

24 19.0 8.2 13.4 19.2 8.4 13.9 19.1 10.7 15.2

25 18.3 6.4 13.4 19.0 6.0 13.8 19.5 7.6 15.1

26 22.5 16.5 19.9 22.6 16.4 20.0 23.6 17.5 20.8

27 20.8 9.3 17.8 20.6 11.3 17.9 21.6 13.2 19.0

28 20.9 6.9 14.0 22.2 7.8 14.7 22.2 9.2 15.8

29 23.2 8.7 15.2 23.2 9.7 15.2 24.7 11.2 17.0

30 15.9 6.2 10.3 17.0 7.1 10.9 18.0 8.6 12.5

Month 30.7 6.2 18.9 30.7 6.0 19.1 31.4 7.6 20.2

Year 33.6 –21.0 9.8 34.1 –20.4 10.0 35.4 –19.1 10.8

Remarks Good Good Good

74 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

October

1 15.8 13.7 14.7 19.5 18.6 19.1 17.2 15.0 16.0 16.2 15.1 15.4 16.1 14.2 15.1 17.7 14.7 16.0 20.8 20.3 20.52 15.5 13.9 14.6 19.2 18.7 18.9 16.5 15.0 15.6 17.1 14.9 15.2 15.5 14.6 15.1 16.2 15.0 15.6 20.5 20.2 20.43 15.4 12.4 14.2 19.2 18.2 18.7 16.4 13.3 15.4 16.0 14.2 14.8 15.9 13.8 15.1 16.2 14.2 15.2 20.5 19.9 20.24 14.4 11.4 12.9 18.8 18.1 18.4 16.2 12.2 14.1 14.6 13.8 14.2 14.9 12.3 13.7 15.9 12.7 14.3 20.4 19.8 20.15 13.6 10.6 12.4 18.2 17.2 17.8 14.6 11.5 13.5 14.4 13.4 13.9 14.3 12.4 13.6 14.9 12.3 13.5 20.1 19.3 19.66 12.3 9.2 10.7 17.8 16.9 17.3 14.2 9.8 11.9 13.8 13.0 13.4 12.7 10.5 11.7 13.4 10.6 12.1 19.6 19.1 19.37 13.6 10.3 11.8 17.7 16.6 17.1 16.0 11.1 13.3 14.1 13.2 13.6 13.3 10.6 11.9 14.4 11.2 12.8 19.5 19.0 19.28 14.6 11.4 13.0 17.6 16.8 17.2 17.0 12.3 14.5 14.2 13.4 13.8 14.5 11.6 12.9 15.2 12.5 13.8 19.6 18.8 19.29 15.1 13.0 14.0 17.4 17.1 17.2 17.0 14.2 15.4 14.2 13.8 14.0 15.8 13.6 14.6 15.5 14.0 14.7 19.4 19.0 19.2

10 14.3 12.9 13.9 17.6 17.0 17.3 15.9 13.9 15.2 14.1 13.7 14.0 15.8 14.7 15.2 15.0 13.7 14.6 19.3 18.6 19.011 13.5 12.1 12.7 17.5 16.7 17.1 15.0 12.9 13.8 13.7 13.4 13.6 15.3 13.6 14.4 14.0 12.8 13.4 18.9 18.3 18.612 12.4 11.3 11.8 16.7 16.1 16.4 14.3 12.0 12.9 13.5 13.1 13.4 13.6 12.0 12.6 13.1 12.1 12.6 18.3 17.8 18.113 12.7 10.2 11.5 16.4 15.6 16.0 15.1 10.3 12.6 13.6 12.9 13.2 13.4 10.6 12.0 13.4 11.1 12.3 18.6 17.5 18.014 12.5 10.3 11.5 16.3 15.5 15.9 14.0 10.7 12.5 13.6 13.0 13.3 12.6 10.5 11.6 13.1 11.4 12.4 17.9 17.6 17.815 14.1 12.3 12.8 16.2 15.8 15.9 15.1 13.5 14.4 15.2 13.5 14.0 13.9 12.6 13.2 13.7 13.0 13.3 17.6 17.5 17.616 14.1 12.5 13.6 15.9 15.6 15.8 15.0 13.2 14.3 15.4 13.8 14.5 14.4 13.3 13.8 14.4 13.3 13.8 17.7 17.3 17.517 12.5 11.0 11.9 15.7 15.3 15.5 13.8 11.5 12.6 13.8 13.3 13.5 13.3 11.9 12.6 13.3 11.9 12.6 17.4 16.8 17.218 11.7 9.9 10.7 15.4 14.7 15.0 13.5 10.1 11.6 13.3 13.0 13.2 12.1 10.7 11.4 12.2 10.8 11.6 16.8 16.5 16.619 11.2 10.4 10.9 14.8 14.2 14.5 13.0 11.0 11.9 13.1 11.4 12.5 11.0 10.6 10.7 11.6 10.9 11.3 16.6 16.1 16.420 11.1 9.4 10.4 14.3 13.5 13.9 12.4 10.2 11.3 13.3 12.9 13.1 10.8 9.9 10.4 11.2 10.3 10.7 16.2 15.7 16.021 10.4 9.3 9.8 13.6 13.1 13.4 11.7 9.9 10.6 13.2 12.8 13.0 10.0 9.2 9.7 10.6 9.8 10.2 15.8 15.4 15.622 10.4 9.7 10.0 13.2 12.5 12.9 11.4 10.2 10.7 13.2 12.8 13.0 10.0 9.3 9.6 10.5 9.9 10.2 15.4 15.0 15.223 10.1 9.3 9.6 12.6 11.9 12.3 11.0 9.7 10.3 13.0 12.7 12.8 9.5 8.9 9.2 10.1 9.4 9.8 15.0 14.6 14.824 10.2 9.6 9.9 12.0 11.7 11.9 11.1 10.0 10.5 13.0 12.8 12.9 9.6 8.9 9.2 10.1 9.6 9.8 14.6 14.3 14.425 10.9 9.7 10.2 12.0 11.7 11.8 12.1 10.1 10.9 13.3 12.8 12.9 10.2 9.1 9.6 10.5 9.6 10.1 14.5 14.2 14.326 10.8 8.9 9.8 12.3 11.5 11.8 12.3 9.0 10.6 12.9 12.4 12.7 10.4 8.7 9.6 10.8 8.9 9.9 14.4 13.9 14.127 10.8 8.1 9.5 12.1 11.6 11.8 12.7 8.3 10.3 13.0 12.2 12.6 10.2 8.0 9.1 11.1 9.2 10.1 14.3 13.8 14.028 9.8 7.9 8.9 11.9 11.3 11.6 11.3 8.0 9.6 12.8 12.1 12.5 9.8 8.0 8.9 10.3 8.7 9.4 14.0 13.6 13.829 10.2 7.6 8.9 11.5 11.2 11.4 11.8 7.3 9.3 12.9 12.1 12.5 9.7 7.4 8.4 10.3 8.5 9.4 13.8 13.4 13.630 11.4 8.5 9.6 11.4 11.1 11.2 12.8 8.8 10.4 13.1 12.4 12.7 10.3 8.3 9.0 11.2 9.2 9.9 13.6 13.4 13.531 13.4 11.4 12.3 11.5 11.2 11.3 15.6 12.0 13.8 13.3 13.1 13.2 12.6 10.3 11.4 12.7 11.2 11.9 14.1 13.5 13.7

Month 15.8 7.6 11.6 19.5 11.1 15.0 17.2 7.3 12.6 17.1 11.4 13.5 16.1 7.4 11.8 17.7 8.5 12.2 20.8 13.4 17.0

Table 13 75
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

November

1 12.0 9.7 11.1 11.9 11.2 11.5 13.1 9.0 11.4 13.1 12.5 12.8 12.0 10.1 11.1 11.6 10.1 11.0 13.7 13.2 13.42 10.2 8.2 9.3 11.6 11.2 11.4 10.6 7.1 9.2 12.7 12.1 12.4 10.1 8.8 9.6 10.6 9.0 10.0 13.4 13.2 13.33 10.9 8.3 10.1 11.8 11.1 11.4 12.1 7.3 10.5 12.9 12.1 12.6 11.1 9.0 10.2 10.8 8.8 10.2 13.2 12.8 13.04 9.4 6.8 8.0 11.2 10.7 10.9 11.3 5.3 7.7 12.5 9.4 11.6 9.0 7.5 8.5 9.4 7.5 8.7 13.0 12.6 12.85 9.4 7.4 8.6 10.9 10.4 10.7 10.6 6.9 8.9 12.1 9.7 11.6 9.4 7.9 8.8 9.5 8.0 8.9 12.7 12.0 12.46 9.3 7.0 8.2 10.5 10.1 10.2 9.8 6.6 8.2 12.3 11.6 11.9 8.4 7.2 7.9 9.0 7.4 8.2 12.2 11.9 12.07 10.9 7.9 9.5 10.2 9.9 10.0 12.0 7.5 9.8 12.7 12.1 12.4 9.7 7.5 8.6 10.3 7.9 9.2 12.2 11.7 12.08 10.5 7.5 9.1 10.3 9.7 10.0 10.8 6.6 8.9 12.7 11.9 12.3 9.6 7.7 8.9 10.3 7.8 9.0 12.1 11.5 11.89 7.5 5.0 6.3 9.8 9.1 9.5 7.0 3.5 5.4 12.1 11.3 11.6 7.7 5.3 6.6 7.8 5.6 6.7 11.5 10.9 11.2

10 6.6 3.6 5.1 9.1 8.6 8.8 5.9 2.0 4.0 11.5 10.9 11.2 6.0 4.2 5.1 6.4 4.3 5.4 11.2 10.6 10.911 8.2 5.4 6.8 8.7 8.4 8.5 8.4 4.1 6.3 12.1 11.4 11.7 7.2 5.0 6.0 8.0 5.4 6.7 10.7 10.4 10.612 7.1 4.3 5.9 8.4 7.6 8.0 6.8 3.7 5.4 12.1 8.4 10.7 6.5 4.7 5.9 6.9 4.6 6.0 10.4 9.9 10.213 4.4 2.7 3.6 7.6 6.6 7.1 6.3 2.6 4.2 10.4 7.2 9.1 4.7 3.1 3.8 4.7 3.0 3.9 9.9 9.2 9.614 5.0 2.4 3.8 6.8 6.3 6.6 6.2 1.7 4.0 11.0 10.1 10.6 4.3 2.2 3.3 5.3 2.9 4.2 9.4 9.0 9.215 6.6 3.4 4.8 7.0 6.3 6.6 8.2 3.2 5.4 11.3 10.6 10.9 5.4 3.0 4.0 6.3 4.0 5.1 9.4 9.0 9.216 6.4 4.3 5.3 6.6 6.4 6.5 7.6 4.8 6.1 11.3 10.6 10.9 5.2 3.9 4.5 6.2 4.6 5.4 9.3 9.0 9.117 7.2 4.7 6.0 6.6 6.3 6.4 8.8 4.5 6.5 11.3 10.7 11.0 5.8 4.0 4.8 6.6 4.6 5.7 9.3 8.8 9.118 8.9 6.6 7.7 6.5 6.3 6.4 10.3 7.0 8.5 12.1 11.3 11.7 6.8 5.2 6.0 8.0 6.3 7.2 9.2 9.0 9.119 10.1 6.9 8.7 7.0 6.3 6.6 11.2 4.3 9.1 12.4 11.6 12.0 8.0 6.2 6.9

—

—

— 9.4 9.1 9.3

20 8.0 5.8 7.0 6.8 6.5 6.6 8.5 5.0 6.9 12.0 9.3 11.5 6.5 5.0 5.8

—

—

— 9.2 9.0 9.1

21 8.2 7.4 7.8 6.8 6.6 6.6 8.9 7.8 8.7 11.9 9.8 11.3 6.7 6.1 6.4

—

—

— 9.1 8.9 9.0

22 8.7 6.4 7.9 7.8 6.5 6.7 9.2 5.9 7.8 13.4 11.5 11.8 7.2 5.8 6.6

—

—

— 9.0 8.8 8.9

23 7.5 5.0 6.2 6.8 6.3 6.5 8.3 4.0 6.0 11.8 11.1 11.5 6.0 4.4 5.2 7.6 5.6 6.5 8.9 8.6 8.824 9.6 6.0 7.8 7.1 6.4 6.7 11.0 5.3 7.7 12.1 11.2 11.7 8.0 4.6 5.7 9.0 6.4 7.6 8.9 8.6 8.825 12.4 8.8 11.2 7.3 6.9 7.1 13.2 10.2 12.0 14.0 11.6 12.8 10.3 7.3 9.2 11.3 8.4 10.1 9.4 8.7 9.026 8.8 4.6 6.2 7.0 6.5 6.7 10.2 4.6 7.2 11.6 10.7 11.0 8.4 4.2 6.0 8.4 5.5 6.6 9.0 8.4 8.727 6.8 3.9 5.4 6.8 6.2 6.5 7.8 3.6 5.6 11.5 10.5 11.0 4.8 3.1 4.1 6.6 4.5 5.6 8.6 8.3 8.428 10.3 6.0 7.8 7.1 6.4 6.7 10.8 5.8 8.1 12.3 10.5 11.2 8.9 4.3 5.8 9.0 5.4 6.9 8.4 8.3 8.329 9.1 6.2 7.4 7.0 6.4 6.7 10.3 7.1 8.5 10.8 9.8 10.3 7.6 5.1 6.0 8.1 5.8 6.9 8.4 8.1 8.330 8.0 6.1 7.0 6.9 6.4 6.6 9.4 7.0 7.9 11.1 10.2 10.7 5.9 4.6 5.3 7.3 5.5 6.3 8.4 8.0 8.2

Month 12.4 2.4 7.3 11.9 6.2 8.0 13.2 1.7 7.5 14.0 7.2 11.5 12.0 2.2 6.6 e11.6 e2.9 e7.2 13.7 8.0 10.1

76 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

December

1 10.0 7.2 8.2 7.2 6.5 6.8 10.7 7.8 9.1 11.6 9.6 10.8 7.6 5.5 6.4 8.8 6.6 7.5 8.3 8.0 8.22 7.7 6.1 6.8 6.8 6.2 6.4 9.2 6.8 7.9 10.6 9.8 10.2 6.1 4.8 5.3 7.0 5.6 6.2 8.0 7.8 7.93 7.6 5.8 6.6 6.6 6.0 6.3 8.8 6.3 7.3 10.7 10.0 10.4 5.2 4.1 4.7 6.8 5.0 5.8 8.0 7.7 7.84 6.3 4.9 5.5 6.2 5.6 5.9 7.3 5.2 6.0 10.3 9.8 10.0 4.6 3.4 3.8 5.7 4.2 5.0 7.8 7.5 7.65 7.2 4.7 6.0 6.2 5.2 5.8 8.4 4.6 6.5 10.6 9.9 10.3 4.8 3.4 4.0 6.2 4.5 5.3 7.5 7.0 7.36 4.7 3.5 4.0 5.2 4.7 5.0 4.9 3.3 4.0 9.9 9.3 9.5 3.6 2.2 2.5 4.5 3.5 4.0 7.0 6.7 6.97 4.8 3.7 4.2 5.3 4.7 4.9 7.4 3.9 5.5 9.6 5.7 7.2 4.1 2.3 3.1 5.3 3.9 4.6 6.8 6.7 6.78 7.3 4.6 6.0 5.5 5.0 5.2 7.5 5.4 6.3 9.7 7.1 8.7 4.4 3.3 3.9 6.9 5.0 5.7 6.9 6.7 6.89 6.9 5.3 6.2 5.3 4.9 5.1 7.8 5.6 6.6 9.9 9.0 9.5 4.0 2.9 3.6 6.3 4.6 5.6 7.0 6.6 6.8

10 7.2 6.3 6.8 5.4 5.1 5.3 8.3 6.9 7.8 9.9 7.3 9.0 5.4 4.0 4.5 6.6 5.9 6.3 6.9 6.7 6.711 7.5 6.1 6.9 5.4 5.2 5.3 7.7 6.7 7.1 9.9 7.3 9.1 5.4 5.1 5.3 7.1 6.6 6.8 6.8 6.7 6.812 7.4 6.4 7.0 5.4 5.0 5.2 7.9 6.7 7.3 9.9 9.5 9.8 5.2 4.5 4.9 6.8 6.0 6.5 6.8 6.5 6.613 7.9 6.4 7.0 5.3 5.0 5.2 8.7 6.7 7.5 10.3 9.6 9.9 5.3 4.4 4.8 7.2 5.9 6.5 6.7 6.4 6.514 6.4 3.2 5.0 5.0 3.9 4.5 6.7 3.5 5.4 9.8 8.6 9.2 4.6 1.7 3.4 6.1 3.5 4.9 6.4 5.8 6.115 3.7 2.2 2.8 3.9 3.2 3.5 4.5 2.4 3.1 8.9 8.3 8.5 1.7 .6 1.0 4.2 3.0 3.5 5.8 5.3 5.516 4.7 1.7 3.2 4.0 3.3 3.6 5.5 1.8 3.5 9.5 8.4 8.9 1.8 .3 1.1 5.0 2.8 3.8 5.5 5.2 5.317 5.4 3.0 4.3 4.0 3.2 3.6 6.3 3.3 4.7 9.5 8.9 9.2 2.8 1.6 2.0 5.0 3.8 4.5 5.2 4.8 5.018 4.2 1.7 3.0 3.6 2.4 3.0 5.2 1.9 3.5 9.6 8.6 9.0 2.0 .6 1.4 5.1 3.1 4.1 5.2 4.6 4.919 5.4 2.9 4.3 3.2 2.6 2.9 6.4 3.4 4.9 9.9 9.0 9.4 3.1 1.5 2.3 5.6 4.0 4.8 5.2 4.6 4.920 5.1 .0 2.2 3.2 1.7 2.3 5.9 –.3 3.0 9.4 6.9 7.9 3.0 .2 1.4 5.0 1.9 3.3 5.0 3.8 4.421 1.7 .0 .8 2.4 1.7 2.0 1.5 –.4 .3 9.1 7.7 8.4 .8 .2 .5 3.7 1.7 2.6 3.9 3.5 3.722 4.0 1.0 2.5 2.4 1.8 2.1 5.2 .5 2.8 9.5 8.6 9.1 2.0 .5 1.2 4.8 2.8 3.8 4.1 3.7 3.923 10.4 3.7 6.1 3.2 2.2 2.6 10.8 4.9 7.3 12.9 8.3 9.8 8.2 1.9 3.5 8.4 4.4 5.6 4.2 3.7 3.924 7.4 3.7 4.8 2.8 1.9 2.4 10.2 4.6 6.6 8.3 7.3 7.7 5.0 1.4 2.4 5.8 3.8 4.5 4.2 3.7 4.025 4.0 2.3 3.2 2.4 1.7 2.1 5.3 3.1 4.1 8.3 7.6 7.9 1.5 .5 1.1 4.4 3.1 3.6 3.9 3.5 3.726 2.7 .0 1.8 2.1 1.2 1.8 — — — — — e7.9 1.0 .3 .7 3.4 1.7 2.8 3.5 2.5 3.227 2.2 .5 1.2 1.3 .9 1.1 — — — — — e7.6 .6 .3 .4 3.0 1.9 2.4 2.6 2.3 2.528 2.2 .0 1.2 1.7 .8 1.2 — — — — — e7.5 .7 .3 .5 — — — 2.5 2.1 2.329 4.4 2.2 3.4 1.6 1.4 1.5 — — — — — e8.5 1.6 .6 1.1 — — — 2.4 1.8 2.230 5.3 2.5 4.0 1.6 1.4 1.5 — — — — — e8.3 2.1 .8 1.5 — — — 2.6 2.1 2.431 5.1 2.3 3.9 1.7 1.5 1.6 — — — — — e8.2 2.2 .7 1.4 — — — 2.8 2.5 2.6

Month 10.4 .0 4.5 7.2 .8 3.7 e10.8 e–.4 e5.5 e12.9 e5.7 8.9 8.2 .2 2.7 e8.8 e1.7 e4.8 8.3 1.8 5.3

Table 13 77
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

January

1 5.7 3.4 4.5 2.0 1.6 1.8

—

—

—

—

— e8.2 2.7 1.6 2.0

—

—

— 2.7 2.5 2.6

2 4.5 2.6 3.6 2.0 1.4 1.7

—

—

—

—

— e8.4 2.0 1.0 1.6

—

—

— 2.6 2.3 2.5

3 6.9 4.5 5.8 1.9 1.4 1.7

—

—

—

—

— e9.5 3.4 2.0 2.8

—

—

— 3.1 2.5 2.8

4 6.1 4.4 5.3 1.8 1.6 1.7 7.1 5.5 6.2 8.8 6.6 7.9 3.4 2.6 3.0 6.0 4.9 5.3 3.3 2.9 3.15 5.2 3.8 4.5 2.1 1.8 2.0 5.5 4.2 5.1 8.5 6.2 8.0 2.6 1.7 2.1 5.0 4.0 4.4 3.1 2.7 2.96 3.8 .2 2.2 1.9 1.5 1.7 4.5 .2 2.6 8.0 1.1 6.0 1.7 .2 .9 4.0 1.8 3.2 2.7 2.4 2.67 4.4 2.8 3.5 1.9 1.4 1.6 5.1 2.9 3.9 7.7 6.2 7.1 2.0 1.1 1.5 4.7 3.5 3.9 2.7 2.3 2.58 3.9 1.1 2.8 1.9 1.7 1.8 4.3 .4 3.1 8.2 2.9 6.9 1.4 .4 .9 4.0 2.4 3.4 2.8 2.3 2.69 4.0 1.9 3.2 1.9 1.7 1.8 4.8 2.4 3.7 8.3 7.3 7.9 1.7 .6 1.2 4.3 2.9 3.7 2.5 2.1 2.3

10 5.1 3.6 4.2 2.2 1.9 2.1 5.8 4.1 4.6 8.6 8.2 8.3 2.3 1.5 1.7 4.8 3.9 4.2 2.5 2.2 2.411 4.4 3.1 3.7 2.2 2.0 2.1 5.3 3.5 4.2 8.7 8.1 8.4 2.1 1.2 1.6 4.6 3.6 4.1 2.4 1.9 2.212 3.8 2.9 3.3 2.4 2.2 2.3 5.0 2.8 3.7 8.4 4.2 6.5 2.0 1.3 1.7 4.2 3.6 3.9 2.5 2.3 2.413 5.2 3.2 4.2 2.4 2.1 2.3 5.7 3.3 4.4 8.3 5.7 7.5 2.9 1.8 2.1 5.4 4.1 4.5 2.6 2.3 2.414 6.7 3.8 4.7 2.9 2.4 2.6 8.7 3.3 5.8 11.9 6.0 7.4 5.0 2.5 3.6 6.9 4.6 5.6 3.1 2.4 2.715 4.6 3.2 3.9 2.6 2.2 2.4 5.2 3.3 4.2 7.5 6.7 7.0 2.5 1.1 1.8 4.6 3.5 4.0 2.7 2.3 2.616 4.2 2.7 3.4 2.5 2.2 2.4 4.6 2.8 3.7 7.6 7.0 7.3 1.4 .7 1.0 4.1 3.3 3.6 2.6 2.3 2.517 3.8 1.6 2.8 2.4 2.1 2.2 4.0 1.3 2.7 7.7 7.0 7.3 1.3 .3 .8 4.0 2.8 3.3 2.4 1.7 2.018 1.6 .0 .5 2.2 1.8 2.0 1.3 –.4 .2 7.2 6.8 7.0 .5 .2 .3 2.9 2.0 2.4 1.7 1.0 1.319 2.0 –.1 .9 2.1 1.7 1.9 .9 –.4 .0 7.9 7.0 7.4 .6 .1 .4 3.3 1.8 2.6 1.7 .9 1.420 3.0 1.1 1.9 2.1 1.8 2.0 3.1 .6 1.4 7.9 7.3 7.6 1.1 .4 .7 3.5 2.6 3.0 1.7 1.3 1.521 1.1 –.3 .1 2.3 2.1 2.2 .6 –.5 –.3 7.3 6.7 7.0 .5 .1 .2 2.6 1.4 1.9 1.3 1.0 1.222 .3 –.6 –.1 2.3 2.2 2.2 –.3 –.4 –.4 7.6 6.2 7.0 .4 .0 .1 2.3 .9 1.6 1.6 1.2 1.423 –.2 –.6 –.4 2.4 2.1 2.2 –.4 –.4 –.4 7.1 6.0 6.6 .1 –.1 .0 2.0 .9 1.4 1.3 1.0 1.124 .8 –.2 .4 2.4 2.2 2.3 –.4 –.4 –.4 7.6 6.7 7.2 .3 .0 .1 2.3 1.3 1.8 1.3 1.1 1.225 1.6 .6 1.1 2.5 2.3 2.4 –.4 –.4 –.4 7.8 7.3 7.6 .5 .1 .3 2.8 2.0 2.4 1.3 1.0 1.226 1.4 .7 1.0 2.5 2.3 2.4 –.3 –.4 –.3 7.7 7.2 7.5 .4 .2 .3 2.5 1.9 2.2 1.3 1.2 1.327 1.3 –.1 .6 2.5 2.4 2.5 –.2 –.4 –.3 7.7 7.0 7.3 .7 .0 .2 2.1 1.1 1.7 1.2 1.1 1.228 1.0 –.3 .2 2.6 2.4 2.5 –.2 –.4 –.3 7.7 6.7 7.1 .6 –.1 .2 2.0 .8 1.3 1.2 1.1 1.229 1.4 –.3 .5 2.6 2.4 2.5 .1 –.4 –.3 8.1 6.7 7.4 .8 –.1 .3 2.4 .8 1.6 1.2 1.2 1.230 2.7 .7 1.6 2.6 2.4 2.5 1.5 .1 .7 8.3 7.6 8.0 1.7 .5 .9 3.3 2.1 2.5 1.3 1.2 1.231 2.4 .1 1.1 2.6 2.4 2.5 2.0 –.4 .6 8.3 7.5 7.8 1.6 .3 .8 3.0 1.3 2.1 1.3 1.2 1.2

Month 6.9 –.6 2.4 2.9 1.4 2.1 e8.7 e–.5 e2.1 e11.9 e1.1 e7.5 5.0 –.1 1.1 e6.9 e.8 e3.1 3.3 .9 2.0

78 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

February

1 2.0 –0.3 0.7 2.6 2.5 2.5 1.0 –0.4 0.0 8.4 7.0 7.6 1.6 0.0 0.6 2.9 0.8 1.7 1.3 1.2 1.22 2.3 –.2 .9 2.7 2.5 2.6 1.8 –.4 .3 8.4 7.2 7.8 1.8 .1 .8 3.1 .9 2.0 1.3 1.2 1.33 3.0 .0 1.4 2.7 2.5 2.6 3.1 –.3 1.0 8.5 4.7 7.1 2.0 .3 1.1 3.5 1.4 2.4 1.3 1.2 1.34 2.7 1.1 2.0 2.7 2.5 2.6 3.5 2.1 2.8 7.6 5.0 6.7 1.9 1.1 1.5 3.4 2.2 2.9 1.3 1.2 1.35 4.5 .8 2.4 2.7 2.5 2.6 6.0 .8 2.9 8.0 7.5 7.6 2.9 .7 1.6 4.2 2.2 3.0 1.3 1.2 1.36 4.6 1.0 2.5 2.7 2.5 2.6 6.3 1.3 3.2 8.2 7.6 7.8 3.0 .8 1.7 4.4 2.4 3.1 1.4 1.3 1.37 4.7 .8 2.5 2.9 2.6 2.7 6.6 .9 3.2 8.6 7.5 8.0 3.0 .8 1.7 4.4 2.0 3.1 1.4 1.3 1.48 4.7 1.9 3.1 2.9 2.7 2.8 6.1 2.0 3.8 8.8 7.8 8.2 2.9 1.1 1.9 4.5 2.6 3.4 1.4 1.4 1.49 5.2 2.4 3.7 3.0 2.8 2.9 7.2 2.8 4.6 8.6 7.8 8.1 3.6 1.4 2.3 5.1 3.0 3.9 1.5 1.4 1.5

10 3.7 1.4 2.0 3.0 2.8 2.9 4.7 1.7 2.7 7.8 3.2 4.6 2.5 .7 1.8 3.8 2.3 3.1 1.5 1.1 1.311 3.4 1.4 2.1 3.0 2.8 2.9 4.1 1.9 2.6 6.5 4.3 5.8 1.9 .6 1.0 3.2 2.1 2.5 1.2 1.0 1.112 4.4 1.1 2.5 3.0 2.8 2.9 5.4 1.4 3.0 7.5 6.2 6.8 2.3 .5 1.2 3.7 1.9 2.6 1.4 1.2 1.313 4.8 1.6 2.7 3.1 2.9 3.0 6.2 1.8 3.3 7.8 6.8 7.1 2.8 .7 1.4 3.9 2.1 2.8 1.4 1.2 1.314 4.2 .6 2.4 3.2 3.0 3.1 5.6 .6 2.9 7.8 6.5 7.1 2.4 .4 1.3 3.8 1.5 2.7 1.5 1.3 1.415 4.1 1.8 2.8 3.3 3.1 3.2 5.0 2.2 3.5 7.0 3.8 5.6 3.3 1.5 2.2 4.5 3.0 3.5 1.5 1.3 1.416 5.7 2.4 3.7 3.4 3.1 3.2 6.8 3.2 5.0 7.5 5.6 6.5 3.3 1.1 2.1 5.1 3.0 3.9 1.5 1.3 1.417 4.7 2.4 3.3 3.4 3.1 3.2 5.6 3.1 4.2 7.0 5.5 6.2 2.6 1.0 1.7 4.4 2.9 3.6 1.8 1.3 1.518 5.0 1.2 2.9 3.4 3.1 3.2 6.1 1.6 3.6 7.3 6.1 6.5 2.6 .7 1.5 4.4 2.4 3.3 1.6 1.2 1.419 3.5 .3 1.5 3.4 3.2 3.3 4.6 .6 1.9 7.1 5.9 6.3 2.1 .4 1.0 3.7 1.8 2.6 1.5 1.0 1.220 4.0 .8 1.9 3.4 3.2 3.3 5.3 .6 2.2 7.4 6.4 6.8 2.6 .6 1.4 4.2 2.2 3.0 1.4 1.0 1.221 2.2 .6 1.6 3.4 3.2 3.3 2.7 .3 1.7 6.8 5.7 6.5 1.5 .6 1.1 3.2 2.1 2.8 1.5 1.2 1.422 3.8 1.7 2.6 3.5 3.3 3.4 4.1 1.8 2.8 7.6 6.6 7.1 2.3 1.1 1.6 3.8 2.8 3.2 1.4 1.1 1.323 4.8 1.4 3.0 3.5 3.3 3.3 5.3 1.5 3.2 7.8 7.0 7.3 3.1 1.1 1.8 4.4 2.5 3.3 1.4 1.2 1.324 3.9 .0 1.6 3.5 3.3 3.4 5.0 –.2 1.8 7.7 6.6 7.0 2.3 .3 1.2 3.9 1.8 2.7 1.5 1.1 1.325 3.9 .2 1.6 3.5 3.3 3.4 5.0 –.2 1.6 7.6 6.3 6.9 2.6 .4 1.3 3.6 1.9 2.6 1.4 1.1 1.326 3.4 –.3 1.4 3.5 3.3 3.4 5.1 –.5 1.6 8.0 6.4 7.2 2.4 .2 1.2 3.8 1.3 2.5 1.5 1.3 1.427 3.9 .1 1.5 3.5 3.3 3.4 5.6 –.4 1.7 7.8 6.8 7.2 2.9 .4 1.3 3.9 1.7 2.6 1.5 1.2 1.328 3.1 –.1 1.5 3.6 3.3 3.5 4.2 –.4 1.5 7.9 6.0 7.2 2.2 .4 1.3 3.6 .6 2.6 1.6 1.3 1.5

Month 5.7 –.3 2.2 3.6 2.5 3.0 7.2 –.5 2.6 8.8 3.2 7.0 3.6 .0 1.4 5.1 .6 2.9 1.8 1.0 1.3

Table 13 79
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

March

1 2.5 –0.2 1.3 3.6 3.2 3.4 2.4 –0.4 1.0 7.3 5.6 6.7 2.0 0.3 1.1 3.3 0.6 2.5 1.6 1.2 1.42 3.1 1.2 2.0 3.4 3.2 3.3 4.4 .9 2.3 7.6 6.6 7.2 2.2 .6 1.3 3.5 2.2 2.8 1.6 1.2 1.33 3.0 .1 1.2 3.4 3.1 3.3 5.0 –.4 1.4 7.6 6.8 7.1 2.3 .1 .9 3.4 1.4 2.2 1.3 1.0 1.14 3.0 –.3 1.0 3.5 3.1 3.3 4.8 –.5 .9 7.8 6.5 7.1 1.9 .0 .8 3.7 .8 2.1 1.2 .9 1.15 4.5 –.1 1.7 3.5 3.2 3.3 6.9 –.5 1.9 8.2 6.8 7.4 3.1 .1 1.3 4.4 1.4 2.7 1.4 1.0 1.26 4.8 .5 2.6 3.6 3.2 3.4 6.8 .1 3.1 8.2 7.2 7.7 3.1 .3 1.8 4.5 2.0 3.2 1.6 1.2 1.47 5.8 2.3 3.8 3.6 3.3 3.5 7.2 2.8 4.4 8.2 6.7 7.6 4.0 1.5 2.6 5.2 3.0 4.0 1.7 1.4 1.58 3.7 –.7 2.2 3.6 3.1 3.4 4.7 –.2 3.3 7.4 3.6 5.8 2.9 –.1 1.9 3.9 .2 2.8 1.6 .4 1.39 1.7 –.5 .4 3.5 3.1 3.3 3.8 –.5 .8 6.2 4.7 5.4 .8 .0 .3 2.5 .5 1.3 .9 .5 .7

10 3.2 –.3 1.0 3.6 3.2 3.4 4.9 –.5 1.2 7.3 5.7 6.4 1.6 .1 .6 3.2 .4 1.6 1.2 .7 .911 3.0 –.1 1.4 3.5 3.2 3.3 4.5 –.5 1.8 7.6 6.1 6.7 1.5 .1 .8 3.2 .8 2.0 1.3 .9 1.112 2.6 .5 1.6 3.5 3.3 3.4 3.3 .9 2.4 7.4 2.5 5.3 1.4 .3 .8 2.8 1.3 2.2 1.2 1.0 1.213 4.0 1.2 2.4 3.5 3.2 3.4 3.9 2.2 2.8 6.9 4.9 6.4 3.2 .6 1.5 4.0 2.2 2.7 1.5 1.0 1.314 6.1 1.0 2.9 3.6 3.2 3.4 7.4 1.6 3.9 7.9 6.7 7.1 4.1 .4 1.8 5.1 1.7 3.0 1.5 1.0 1.215 6.9 1.5 3.4 3.6 3.2 3.4 8.1 2.3 4.4 8.4 6.9 7.3 4.5 .6 2.2 5.4 2.0 3.3 1.4 .9 1.116 7.2 1.9 3.7 3.6 3.2 3.4 8.3 3.0 4.8 8.5 7.0 7.5 4.7 .9 2.4 5.6 2.3 3.6 1.7 1.0 1.317 7.2 1.1 3.5 3.6 3.2 3.4 8.8 2.4 4.8 8.7 6.9 7.6 4.7 .6 2.4 5.8 2.0 3.6 2.2 1.2 1.618 7.0 1.6 3.7 3.6 3.2 3.4 9.2 3.0 5.1 9.0 7.1 7.7 4.8 1.1 2.6 5.9 2.5 3.8 2.3 1.4 1.819 7.6 1.5 3.8 3.6 3.2 3.3 9.4 2.7 5.1 9.0 7.0 7.7 5.3 1.0 2.9 6.4 2.4 4.0 2.2 1.2 1.720 7.1 1.3 3.9 3.5 3.1 3.3 9.2 2.7 5.3 8.9 6.9 7.7 4.7 1.2 3.0 6.3 2.4 4.2 2.4 1.7 2.021 6.3 2.8 4.3 3.4 3.1 3.2 7.9 4.0 5.7 8.6 7.2 7.9 4.6 2.6 3.4 5.9 3.5 4.5 2.5 1.9 2.222 8.5 2.0 4.6 3.6 3.0 3.3 10.7 3.2 5.9 9.5 7.0 7.9 6.3 1.7 3.8 7.8 3.0 5.0 2.9 2.1 2.523 5.5 2.9 4.1 3.5 3.2 3.4 6.8 3.6 5.2 8.3 7.2 7.7 4.2 2.6 3.4 5.6 3.5 4.5 2.7 2.0 2.424 4.7 2.0 3.2 3.8 3.2 3.5 5.1 2.9 4.2 7.3 3.7 6.1 3.8 2.1 2.9 5.3 3.1 4.0 2.6 2.2 2.325 7.3 2.3 4.3 3.8 3.3 3.5 8.4 3.0 5.2 9.0 7.0 7.7 5.3 1.9 3.6 7.3 3.2 5.0 2.7 2.1 2.426 8.3 1.8 4.4 4.0 3.4 3.7 10.1 3.1 5.7 9.3 6.8 7.8 6.3 2.2 4.1 8.1 3.1 5.2 3.6 2.1 2.727 9.3 2.3 5.2 4.4 3.8 4.0 11.2 3.2 6.3 9.9 7.1 8.2 7.2 2.8 4.9 9.0 3.5 6.1 3.8 2.6 3.128 4.7 3.4 4.2 4.3 4.1 4.1 6.3 4.8 5.5 8.1 5.3 6.8 5.0 3.5 4.4 5.8 4.3 5.0 3.1 2.9 3.029 5.7 3.4 4.7 4.3 4.0 4.1 5.0 3.6 4.4 7.5 5.1 6.6 4.3 3.2 3.7 5.6 4.2 4.9 3.3 2.9 3.130 9.5 3.9 6.1 4.5 4.1 4.3 10.3 3.3 6.3 10.1 6.7 8.0 7.5 2.9 5.0 9.3 4.3 6.4 4.2 2.7 3.531 9.7 4.1 6.4 5.1 4.3 4.7 11.0 5.1 7.4 10.1 7.4 8.5 8.2 3.9 6.0 9.5 5.1 7.1 4.3 3.4 3.8

Month 9.7 –.7 3.2 5.1 3.0 3.5 11.2 –.5 4.0 10.1 2.5 7.2 8.2 –.1 2.5 9.5 .2 3.7 4.3 .4 1.8

80 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

April

1 9.7 5.5 6.9 5.7 5.0 5.3 11.8 6.4 8.1 10.3 8.3 9.0 8.9 5.5 7.0 10.1 6.6 8.0 4.6 3.6 4.02 6.4 5.0 5.7 5.6 4.7 5.0 6.9 5.3 6.3 8.9 6.0 7.8 7.1 5.7 6.1 7.7 6.3 6.9 4.1 3.9 4.03 8.7 6.2 7.3 5.3 4.3 4.8 10.3 6.9 8.6 9.7 8.4 8.9 8.4 6.1 7.1 9.6 7.2 8.1 4.6 4.1 4.44 8.6 5.8 6.8 5.4 4.7 5.0 10.5 6.9 8.0 9.7 8.2 8.8 8.2 6.1 7.0 9.4 7.2 8.1 5.6 4.5 5.05 11.0 4.8 7.3 6.8 4.9 5.7 12.6 5.9 8.5 10.8 8.1 9.2 10.3 5.5 7.7 11.4 6.5 8.8 5.7 4.7 5.26 11.0 5.8 8.1 7.8 6.0 6.7 12.6 6.7 9.1 11.0 8.9 9.8 11.2 7.3 9.1 11.8 7.8 9.7 6.1 5.3 5.77 11.0 6.8 8.7 9.1 6.4 7.5 13.1 7.8 9.9 11.1 9.5 10.2 11.6 8.7 10.2 12.1 8.9 10.6 6.6 5.3 6.18 11.6 7.4 9.4 8.8 6.4 7.6 13.2 9.3 11.0 12.9 10.0 11.0 12.4 10.1 11.1 12.6 10.1 11.2 7.9 6.0 7.39 12.2 5.5 8.3 9.8 7.9 8.8 15.0 7.5 10.4 11.6 9.3 10.2 13.0 8.6 10.7 13.4 8.3 10.7 8.1 6.3 7.3

10 12.6 5.3 8.6 11.1 7.9 9.3 15.5 6.7 10.4 11.8 9.3 10.4 13.6 8.6 11.0 13.9 8.2 11.1 10.8 7.8 9.111 11.4 5.8 8.1 10.6 9.7 10.2 14.0 6.8 9.7 11.2 9.4 10.1 12.7 9.4 11.1 12.6 8.8 10.7 10.3 6.4 8.612 9.5 4.4 6.7 10.1 9.3 9.6 12.1 5.5 8.3 10.6 9.0 9.7 10.8 8.1 9.6 11.0 7.4 9.1 9.7 6.3 8.813 10.7 4.5 7.3 10.1 8.4 9.3 13.0 5.4 8.7 11.0 9.0 9.8 11.3 7.5 9.3 11.7 7.1 9.3 9.8 8.3 8.914 12.2 5.2 8.0 10.2 9.0 9.6 14.6 6.1 9.5 11.4 9.3 10.1 12.2 8.0 10.0 12.7 7.8 10.0 9.5 7.5 8.915 11.4 4.6 7.4 10.6 9.4 9.9 14.2 5.5 9.2 11.1 9.1 9.9 12.1 7.9 9.9 12.4 7.6 9.8 9.3 8.3 8.916 11.9 4.2 7.6 11.2 9.4 10.2 15.0 5.1 9.4 11.3 9.0 10.0 12.3 7.7 10.0 12.6 7.2 9.9 9.8 8.7 9.217 13.7 5.1 9.0 11.7 9.2 10.5 16.8 5.9 10.8 11.8 9.3 10.4 14.1 8.4 11.2 14.3 8.0 11.1 12.9 9.4 9.918 14.1 7.0 10.1 12.8 10.8 11.8 16.8 8.3 12.0 11.9 10.1 10.8 15.5 10.5 13.0 15.4 10.3 12.7 13.8 10.1 11.919 14.7 6.6 10.4 12.9 10.8 11.4 17.7 7.7 12.3 12.2 10.0 10.9 16.3 10.7 13.6 15.9 10.1 13.1 13.6 10.2 12.020 16.8 9.4 12.7 12.2 10.6 11.1 18.9 10.5 14.2 13.9 10.8 11.6 17.8 13.0 15.4 17.7 12.2 14.8 14.4 13.0 13.621 14.4 8.5 11.3 13.6 11.9 12.8 16.3 10.2 12.7 13.1 10.7 11.7 16.7 13.4 15.0 15.9 12.1 13.9 14.5 12.0 13.722 13.4 6.1 9.4 13.1 10.9 12.3 16.8 7.0 11.2 11.9 9.9 10.8 15.5 10.9 13.2 15.1 9.7 12.4 13.8 12.9 13.423 10.8 8.2 9.5 12.4 11.3 12.0 12.4 9.5 10.9 14.0 10.4 11.7 13.2 12.0 12.4 12.7 11.3 12.0 13.6 12.5 13.124 13.2 9.3 11.2 12.4 12.0 12.2 14.9 11.4 12.9 14.1 11.3 12.7 14.4 12.3 13.0 14.6 11.8 12.9 13.7 13.1 13.425 11.0 7.8 9.2 12.3 11.7 12.0 12.4 9.0 10.9 11.6 9.9 10.9 13.0 11.3 12.1 13.0 10.4 11.5 13.7 13.2 13.426 13.7 6.6 9.9 12.0 11.6 11.8 16.2 7.5 11.3 12.2 10.1 11.1 14.3 9.7 12.0 14.4 8.9 11.7 13.9 12.9 13.427 11.0 9.3 10.0 12.5 11.9 12.2 12.2 10.2 11.1 12.9 10.9 11.7 13.0 12.1 12.3 12.0 11.6 11.7 13.7 13.1 13.328 12.4 9.0 10.2 12.9 12.2 12.5 14.3 10.4 11.8 12.1 11.0 11.4 13.6 11.4 12.4 13.2 10.9 12.0 13.6 12.9 13.229 14.5 7.3 10.5 12.4 11.9 12.2 17.7 8.4 12.3 12.5 10.2 11.2 15.1 10.5 12.7 15.0 9.4 12.2 13.7 12.6 13.230 11.6 9.0 10.1 12.7 12.3 12.5 12.6 10.1 11.2 13.7 10.9 11.7 13.7 12.3 12.6 12.8 11.4 11.9 13.4 13.1 13.2

Month 16.8 4.2 8.9 13.6 4.3 9.7 18.9 5.1 10.4 14.1 6.0 10.4 17.8 5.5 10.9 17.7 6.3 10.9 14.5 3.6 9.7

Table 13 81
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

May

1 11.9 9.2 10.9 12.9 12.5 12.7 13.3 11.2 12.5 13.9 11.2 12.2 13.3 12.1 12.6 12.8 11.2 12.2 13.5 13.1 13.32 13.8 7.5 10.2 12.7 12.3 12.5 16.3 9.1 12.1 12.3 10.4 11.2 14.1 10.4 12.4 14.1 9.6 11.8 13.6 12.7 13.33 13.1 7.8 10.2 13.1 12.3 12.6 16.4 9.3 12.0 12.0 10.5 11.2 14.1 11.0 12.7 13.9 10.1 12.0 13.9 12.9 13.44 12.4 7.5 9.7 13.7 12.6 13.1 14.7 8.6 11.4 11.9 10.4 11.1 14.2 11.0 12.6 13.2 10.1 11.7 14.1 12.9 13.45 14.5 6.7 10.2 15.2 12.9 14.0 17.8 7.7 12.0 12.4 10.2 11.1 15.4 10.4 12.9 15.0 9.5 12.2 14.0 12.9 13.36 11.3 7.4 9.4 14.1 13.3 13.7 13.3 8.4 10.8 11.5 10.5 11.0 13.6 11.4 12.6 12.6 10.4 11.7 13.8 13.0 13.57 9.0 7.6 8.5 13.7 12.5 13.2 10.4 8.8 9.6 10.9 9.3 10.2 12.4 9.9 11.0 11.2 9.3 10.2 13.5 12.1 12.88 9.6 7.2 8.4 12.6 12.1 12.3 10.3 7.9 9.0 10.9 10.0 10.4 10.7 9.3 10.0 10.3 8.7 9.5 12.2 11.9 12.19 11.8 8.5 9.8 12.8 12.0 12.3 12.9 9.2 10.5 11.6 10.6 11.0 12.2 10.0 10.9 11.9 9.5 10.5 12.4 11.9 12.1

10 15.6 9.4 11.7 15.1 12.4 13.6 17.9 10.2 12.8 12.9 11.0 11.7 15.8 11.2 13.2 15.7 10.5 12.7 13.4 12.1 12.511 17.3 9.5 13.0 14.1 12.3 12.8 19.6 10.1 14.2 13.3 11.1 12.0 18.3 12.6 15.3 17.6 11.8 14.6 15.8 13.1 14.212 15.3 9.5 12.4 14.8 12.4 13.9 17.3 10.4 13.5 12.3 11.1 11.8 17.9 14.6 16.0 16.1 13.2 14.7 16.3 13.4 15.513 14.2 7.1 10.4 15.1 13.7 14.3 16.7 8.0 11.9 12.1 10.4 11.1 16.7 11.8 14.3 14.9 10.5 12.8 15.2 14.2 14.714 13.1 9.1 10.8 14.5 13.9 14.2 14.5 10.0 11.9 12.1 11.0 11.4 15.5 13.0 14.2 14.2 11.8 12.9 14.6 14.0 14.415 12.6 10.1 11.3 15.1 14.0 14.5 13.6 10.9 12.3 11.8 11.3 11.6 15.0 13.7 14.4 13.8 12.3 13.1 14.7 14.3 14.516 11.5 9.1 10.2 15.1 14.2 14.6 12.0 10.1 10.8 12.0 10.3 11.3 14.2 12.3 13.1 13.2 11.4 12.1 14.8 14.1 14.417 15.0 9.7 11.7 15.9 14.2 14.9 16.4 10.4 12.4 12.0 11.3 11.6 15.9 12.7 14.2 15.0 11.6 13.2 15.6 14.2 14.618 13.6 10.1 11.2 16.2 14.8 15.3 14.6 10.8 11.9 11.8 11.3 11.5 15.4 13.3 14.3 14.4 10.9 12.5 15.3 14.5 14.919 13.7 9.2 11.5 16.2 14.6 15.4 15.4 9.8 12.4 11.9 11.1 11.4 16.0 12.6 14.3 14.2 11.0 12.8 15.7 14.5 15.020 14.0 9.1 11.4 15.8 14.3 15.0 15.5 9.9 12.5 11.9 11.0 11.5 16.0 12.7 14.3 14.5 11.9 13.1 15.8 15.2 15.421 11.8 9.6 10.6 15.1 14.2 14.7 12.8 10.5 11.4 11.6 11.2 11.3 14.6 12.9 13.7 12.9 11.8 12.4 15.6 14.6 15.222 11.2 9.4 10.3 15.0 14.4 14.7 11.6 10.3 10.9 11.5 10.7 11.2 13.5 11.9 12.7 12.6 11.2 11.9 15.1 14.5 14.823 10.3 9.4 9.9 14.7 14.2 14.6 11.1 10.1 10.6 11.7 10.9 11.2 12.8 11.7 12.3 12.0 11.1 11.5 14.8 14.2 14.524 9.6 8.7 9.1 14.3 13.6 13.9 10.9 9.5 10.0 11.0 9.3 10.6 11.7 10.3 11.0 11.1 9.8 10.5 14.3 13.3 13.925 9.0 7.9 8.4 13.7 12.6 13.1 10.0 8.4 8.8 10.4 8.6 9.7 10.3 9.6 9.8 9.8 9.2 9.4 13.3 12.6 12.926 10.1 8.5 9.4 12.8 12.3 12.5 10.6 8.7 9.6 11.3 9.0 10.5 10.5 9.5 10.0 10.3 9.2 9.8 12.7 12.3 12.427 12.1 9.7 10.8 13.6 12.4 12.9 13.2 10.6 11.8 12.2 11.0 11.5 13.1 10.4 11.6 13.3 10.1 11.5 13.5 12.4 12.928 14.6 9.9 12.2 13.9 12.8 13.3 17.2 11.2 13.7 14.1 11.4 12.3 16.9 12.2 14.5 17.0 11.6 14.1 15.4 13.0 14.329 15.2 11.1 12.5 18.1 13.5 15.4 16.9 12.3 13.8 18.4 12.2 13.3 17.7 14.7 16.1 17.2 13.7 15.2 16.5 14.2 15.230 14.1 10.7 12.3 17.8 14.9 16.3 16.5 12.3 13.8 13.2 12.1 12.6 17.6 15.1 16.4 16.5 13.5 15.0 17.3 15.2 16.031 12.2 11.0 11.4 16.7 16.2 16.4 13.7 12.5 12.9 12.4 12.0 12.2 16.4 14.9 15.4 14.6 13.2 13.7 17.0 15.2 16.3

Month 17.3 6.7 10.6 18.1 12.0 14.0 19.6 7.7 11.7 18.4 8.6 11.4 18.3 9.3 13.2 17.6 8.7 12.3 17.3 11.9 14.1

82 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

June

1 13.3 10.2 11.6 17.8 15.8 16.5 15.7 11.5 13.1 12.8 11.8 12.2 16.5 13.9 15.1 15.8 12.2 13.8 17.0 15.6 16.22 16.2 10.8 13.1 16.6 14.2 15.3 17.8 11.9 14.3 13.4 11.9 12.5 18.6 14.7 16.5 17.5 12.9 15.0 18.2 16.8 17.33 16.4 11.6 13.8 16.0 14.8 15.1 17.7 12.3 14.8 13.4 12.1 12.6 18.9 15.6 17.4 17.4 13.9 15.6 20.0 17.8 18.94 17.4 12.5 14.8 21.4 15.8 18.2 18.9 13.4 15.9 13.5 12.4 12.9 21.0 16.7 18.8 — — — 20.0 18.1 19.15 17.4 13.0 15.2 21.4 17.7 19.6 18.9 14.1 16.4 13.4 12.6 12.9 21.7 18.3 20.1 19.7 16.4 18.0 22.4 18.2 19.66 15.7 12.8 14.1 21.1 18.2 19.6 16.9 13.4 15.0 13.0 12.3 12.6 20.8 18.2 19.3 18.2 15.6 16.7 21.3 19.1 20.57 18.1 13.8 15.8 18.4 16.4 17.1 20.0 14.5 17.0 13.5 12.5 12.9 22.3 18.3 20.1 19.1 16.0 17.4 23.0 20.9 21.88 21.2 13.8 16.5 19.8 18.0 18.8 22.7 14.6 17.5 23.9 12.4 13.8 23.0 18.5 20.8 19.3 15.0 17.0 25.1 20.2 22.19 20.8 15.9 18.0 22.2 19.4 20.8 20.8 17.2 19.4 21.5 14.0 16.2 22.2 20.2 21.3 20.8 17.7 19.9 23.7 21.3 22.1

10 19.2 15.2 17.0 21.7 18.3 19.9 20.6 16.4 18.3 14.4 13.7 14.0 23.3 20.3 21.7 20.7 18.4 19.4 24.7 22.5 23.711 19.2 16.0 17.6 21.4 19.9 20.6 20.9 17.0 18.7 14.0 13.5 13.7 24.4 21.2 22.8 21.4 18.7 20.0 26.3 23.3 24.212 19.2 16.4 17.7 21.4 20.5 21.0 20.4 17.0 18.5 13.7 13.2 13.4 24.2 22.2 23.3 21.2 19.4 20.3 28.0 23.5 25.613 19.3 16.6 17.9 23.2 21.0 21.8 20.4 17.0 18.4 13.7 13.2 13.4 24.7 22.4 23.5 21.4 19.4 20.4 27.4 24.2 25.514 18.6 14.6 16.9 23.5 21.2 22.3 22.6 16.5 17.7 20.0 13.0 13.9 24.1 20.6 22.8 20.8 17.6 19.8 26.7 24.4 25.315 14.6 12.3 13.3 21.4 18.6 19.8 16.5 13.0 14.6 15.2 12.5 13.1 20.6 16.2 18.0 17.6 14.4 15.8 25.3 22.5 23.716 14.1 12.1 12.8 18.7 17.5 18.1 14.5 12.5 13.3 15.3 12.3 12.7 16.7 15.3 16.0 15.2 13.9 14.5 22.5 21.7 22.217 16.0 12.9 14.1 17.8 17.1 17.4 16.6 13.0 14.4 14.4 12.7 13.2 18.0 15.2 16.4 16.8 14.2 15.3 23.0 21.3 21.718 15.0 13.3 14.0 17.9 16.9 17.3 15.6 13.1 14.0 12.7 12.4 12.6 18.2 16.1 17.0 16.9 15.0 15.7 21.9 21.3 21.519 13.8 12.6 13.3 17.3 16.2 16.8 14.0 12.4 13.3 12.4 12.2 12.3 17.1 15.6 16.4 15.8 14.5 15.2 21.5 21.0 21.320 16.1 11.4 13.7 17.1 15.9 16.4 17.4 11.2 14.1 12.5 11.9 12.2 19.2 14.3 16.7 17.5 13.5 15.4 22.0 20.7 21.221 17.1 13.4 15.2 16.2 15.7 16.0 18.2 12.8 15.4 12.6 12.0 12.3 20.5 16.4 18.3 18.1 14.9 16.6 23.8 21.7 22.622 15.9 14.4 15.2 16.4 15.8 16.0 15.9 14.2 15.0 13.5 12.2 12.5 19.2 17.7 18.4 17.4 16.0 16.7 23.3 22.2 22.623 16.1 12.6 14.4 16.2 15.5 15.9 17.1 12.2 14.6 12.3 11.9 12.1 20.0 15.8 17.9 16.9 14.4 15.8 23.7 21.6 22.624 17.2 13.9 15.6 15.9 15.2 15.6 18.5 13.2 15.8 12.5 12.0 12.2 21.0 16.9 18.9 17.6 14.8 16.4 23.6 22.2 22.925 19.4 15.4 17.2 16.2 15.5 15.8 20.7 15.1 17.8 12.6 12.2 12.4 — — — — — — 24.8 22.8 23.726 19.8 16.7 18.1 16.8 15.9 16.4 22.1 17.1 19.3 12.6 12.2 12.4 — — — — — — 25.6 23.9 24.227 19.9 17.0 18.3 17.0 16.1 16.5 22.8 17.9 20.1 12.6 12.3 12.4 — — — — — — 26.8 23.8 24.728 19.3 17.6 18.3 16.9 16.1 16.5 21.2 19.4 20.1 13.7 12.3 12.6 — — — — — — 26.5 24.4 25.629 19.3 17.6 18.4 16.9 15.2 16.3 21.7 19.0 20.1 13.2 12.4 12.5 — — — — — — 26.2 25.5 25.830 19.0 17.4 18.0 16.2 15.4 15.8 22.1 19.0 20.0 12.5 12.4 12.4 — — — — — — 25.6 23.8 24.9

Month 21.2 10.2 15.7 23.5 14.2 17.8 22.8 11.2 16.6 23.9 11.8 12.9 e24.7 e13.9 e19.1 e21.4 e12.2 e17.0 28.0 15.6 22.4

Table 13 83
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

July

1 17.9 16.3 17.2 16.1 15.1 15.6 20.0 17.8 19.0 12.5 12.3 12.4

—

—

—

—

—

— 24.9 23.9 24.2

2 18.6 16.6 17.7 15.9 15.1 15.5 22.2 18.4 20.0 12.6 12.3 12.4

—

—

—

—

—

— 25.7 24.1 24.8

3 17.6 15.0 16.4 16.0 15.3 15.6 21.8 16.3 18.9 12.5 12.2 12.3

—

—

—

—

—

— 24.7 23.6 24.2

4 17.5 14.8 16.2 16.1 15.2 15.6 21.9 16.0 18.8 12.3 12.0 12.2

—

—

—

—

—

— 24.3 23.7 24.0

5 18.9 15.2 17.1 16.0 15.2 15.7 23.3 16.4 19.7 12.4 12.0 12.2

—

—

—

—

—

— 25.4 23.6 24.4

6 21.4 16.9 19.3 16.6 15.5 15.7 22.4 18.9 21.0 23.1 12.2 17.9

—

—

—

—

—

— 25.1 23.3 24.2

7 18.4 15.9 16.8 24.2 15.4 20.2 20.7 17.2 18.3 18.4 13.0 13.9

—

—

—

—

—

— 23.3 21.9 22.6

8 16.8 15.5 15.8 23.9 22.4 23.3 17.5 15.2 16.8 17.1 12.8 14.3

—

—

— 18.2 16.0 17.3 22.0 20.8 21.6

9 19.9 15.2 16.6 22.6 21.7 22.1 20.4 15.2 16.6 20.8 14.8 15.9

—

—

— 19.4 16.0 17.4 21.5 20.5 21.0

10 19.5 16.6 18.0 24.0 21.7 22.9 21.5 17.5 19.3 16.6 14.0 14.8

—

—

— 22.0 17.1 19.3 23.0 20.9 21.8

11 20.1 17.3 18.6 25.9 23.0 24.3 22.3 18.3 20.0 14.1 13.6 13.9

—

—

— 22.6 19.1 20.7 23.6 22.0 22.8

12 19.1 16.9 17.9 25.5 16.4 19.7 21.6 17.8 19.4 13.6 13.2 13.4

—

—

— 21.5 19.1 20.2 23.5 22.1 22.9

13 18.6 16.5 17.5 16.9 16.1 16.4 21.4 17.6 19.3 13.4 13.0 13.2

—

—

— 20.5 18.4 19.4 24.5 23.0 23.6

14 19.4 17.1 18.1 17.1 16.1 16.5 22.4 18.5 20.3 13.4 13.0 13.2

—

—

— 20.9 18.7 19.7 25.3 23.6 24.4

15 19.9 17.7 18.7 17.3 16.2 16.7 23.3 19.6 21.0 13.4 13.0 13.2

—

—

— 21.0 19.3 20.1 25.5 23.8 24.7

16 19.6 17.1 18.3 17.1 16.4 16.8 23.5 19.1 21.1 13.3 13.0 13.1

—

—

— 20.7 18.9 19.8 26.9 25.1 25.6

17 19.3 17.8 18.5 17.2 16.5 16.9 22.9 20.1 21.3 13.2 13.0 13.1

—

—

— 20.0 18.9 19.5 26.6 25.3 25.9

18 19.9 18.3 18.9 17.2 16.6 17.0 23.6 21.0 21.9 13.2 13.0 13.1

—

—

— 20.3 19.1 19.6 26.7 25.3 26.0

19 20.9 18.4 19.6 17.5 16.5 17.1 25.7 21.1 22.9 13.4 13.0 13.1

—

—

— 21.2 19.5 20.2 28.2 25.4 26.8

20 20.2 18.2 19.2 17.8 16.7 17.4 25.4 20.6 22.6 13.4 12.9 13.1

—

—

— 20.4 19.1 19.8 28.5 26.1 27.3

21 19.4 17.1 18.3 18.1 17.1 17.5 24.4 19.9 22.0 13.1 12.9 13.0

—

—

— 19.5 18.1 18.8 28.3 26.5 27.2

22 19.6 16.9 18.3 18.1 17.3 17.7 27.6 19.9 22.4 25.5 12.9 13.9

—

—

— 19.4 17.5 18.5 28.3 26.5 27.4

23 19.5 17.1 18.2 18.5 17.1 17.9 23.9 19.9 22.4 21.2 13.2 14.4

—

—

— 18.5 16.7 17.7 28.2 26.4 27.3

24 18.4 15.6 17.1 18.3 17.6 17.9 22.6 17.5 19.9 13.2 12.9 13.0

—

—

— 17.5 15.5 16.5 26.5 25.5 26.0

25 19.2 16.6 18.0 18.5 17.6 18.0 22.2 19.0 20.5 13.1 13.0 13.0

—

—

— 17.8 16.2 17.0 25.7 25.3 25.5

26 19.6 17.0 18.5 18.6 17.8 18.1 24.4 19.3 21.7 13.1 12.9 13.0

—

—

— 18.6 16.5 17.4 26.5 25.0 25.7

27 21.8 18.8 20.1 20.0 17.8 18.7 26.0 21.0 23.0 13.3 13.0 13.1

—

—

— 19.6 17.1 18.1 27.0 25.7 26.3

28 20.3 17.1 19.0 21.0 19.2 20.0 21.7 18.3 20.3 13.3 12.9 13.0

—

—

— 17.5 15.2 16.6 26.7 25.2 25.7

29 18.8 16.1 17.6 20.2 19.1 19.6 22.1 16.6 19.4 12.9 12.8 12.9

—

—

— 16.9 14.2 15.6 25.6 24.8 25.2

30 18.8 16.9 17.7 20.8 19.6 20.2 22.7 18.9 20.5 13.0 12.8 12.9

—

—

— 16.9 15.2 15.9 25.1 24.7 24.9

17.3 16.6 16.9 20.8 20.1 20.5 20.0 18.6 19.4 12.9 12.8 12.8

—

—

— 15.4 14.8 15.1 24.8 23.8 24.4

Month 21.8 14.8 17.9 25.9 15.1 18.3 27.6 15.2 20.3 25.5 12.0 13.4

—

—

— e22.6 e14.2 e18.3 28.5 20.5 24.8

84 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

August

1 19.8 16.2 17.9 21.1 20.1 20.6 22.6 19.0 20.5 16.6 12.8 13.5 — — — 17.0 14.7 15.6 24.8 23.7 24.12 21.9 18.9 20.8 21.8 20.4 21.0 23.4 21.2 22.3 22.4 13.0 16.5 — — — 20.1 15.8 18.6 26.0 24.0 24.83 20.9 19.1 20.0 21.8 20.7 21.2 23.8 20.5 22.0 14.2 13.6 13.8 — — — 18.9 17.6 18.3 25.5 24.4 24.94 20.6 18.5 19.6 21.5 20.7 21.2 24.3 20.4 22.1 13.6 13.4 13.5 — — — 18.6 16.9 17.7 25.7 24.6 24.95 21.7 19.0 20.3 22.4 20.8 21.4 25.7 21.2 22.9 13.7 13.3 13.4 — — — 20.2 17.0 18.1 26.6 25.2 25.76 20.2 18.6 19.3 22.2 21.4 21.8 23.7 20.2 21.7 13.5 13.2 13.3 — — — 18.0 16.3 17.1 25.9 25.2 25.47 19.9 17.7 19.0 22.1 21.6 21.8 23.6 18.9 21.2 13.2 13.0 13.1 — — — 17.7 15.4 16.5 26.1 24.9 25.48 20.7 18.3 19.6 22.4 21.5 22.0 24.5 19.9 22.1 13.2 13.0 13.1 — — — 18.0 15.7 16.8 26.7 25.1 25.79 20.5 19.2 19.8 22.6 21.6 22.2 23.9 21.2 22.4 13.3 13.0 13.1 — — — 18.0 16.3 17.0 26.4 25.2 25.8

10 21.3 18.9 20.1 22.7 22.0 22.4 24.8 20.5 22.5 13.2 13.0 13.0 — — — 18.3 16.0 17.0 26.2 25.2 25.611 21.8 19.4 20.5 23.2 22.0 22.6 24.8 21.0 22.8 13.2 12.9 13.0 — — — 18.4 16.2 17.1 26.8 25.4 25.812 22.3 19.2 20.9 23.0 22.0 22.6 24.6 21.0 22.5 13.2 13.0 13.0 — — — 18.0 16.2 16.9 26.4 25.5 25.913 23.4 20.3 21.8 23.7 22.6 22.9 26.1 21.6 23.6 13.2 13.0 13.1 — — — 19.3 16.6 17.7 27.3 26.0 26.514 25.5 20.7 22.3 23.6 22.4 23.1 25.6 21.9 23.1 27.0 13.0 16.5 — — — 23.5 16.7 18.4 27.0 26.3 26.615 23.7 20.1 22.0 24.4 23.2 23.8 22.7 18.8 20.7 22.0 14.7 18.0 — — — 19.1 17.5 18.2 26.3 25.0 25.616 20.6 18.7 19.8 23.8 23.0 23.4 20.8 17.6 19.2 14.7 13.8 14.1 — — — 17.7 16.2 17.0 25.1 24.5 24.817 21.1 19.2 20.1 23.9 23.1 23.5 21.9 18.5 20.0 13.9 13.7 13.8 — — — 17.9 16.3 17.0 25.9 24.5 25.218 19.6 17.8 18.8 24.1 23.1 23.7 20.4 17.1 18.8 13.7 13.4 13.5 — — — 16.9 15.1 16.0 25.7 24.5 25.119 19.3 17.6 18.6 24.2 23.6 23.9 20.4 17.0 18.6 13.5 13.3 13.4 — — — 16.8 14.8 15.8 24.9 24.4 24.620 20.5 18.1 19.2 24.3 23.6 24.0 21.7 18.2 19.7 13.5 13.3 13.4 — — — 17.3 15.5 16.3 24.8 24.2 24.421 22.7 18.7 20.8 24.5 23.6 24.1 22.4 19.6 20.6 19.8 13.3 14.6 — — — 18.5 16.2 17.2 25.6 24.6 25.022 21.5 19.3 20.4 24.9 24.1 24.4 22.0 18.3 20.0 13.7 13.4 13.5 — — — 17.9 16.1 16.9 25.7 24.8 25.223 20.0 17.8 19.0 24.9 24.2 24.5 20.5 16.7 18.5 — — — — — — 16.9 15.0 15.9 25.3 24.4 24.824 19.2 17.6 18.3 25.4 24.6 24.9 19.2 16.9 17.9 — — — — — — 16.1 14.9 15.5 25.0 24.2 24.625 19.0 16.6 18.0 25.2 24.5 24.8 19.8 15.9 17.7 — — — — — — 16.3 14.1 15.2 24.7 23.8 24.226 19.2 16.4 18.0 25.3 24.6 24.9 20.5 15.8 17.9 — — — — — — 16.7 14.1 15.3 25.1 23.9 24.427 19.6 16.9 18.4 25.1 24.8 24.9 20.8 16.1 18.3 — — — — — — 16.8 14.4 15.6 25.2 24.2 24.728 20.9 18.1 19.4 25.3 24.8 25.0 20.8 17.4 19.1 — — — — — — 17.1 14.9 16.0 24.9 24.3 24.629 21.3 19.2 20.2 25.3 22.2 23.7 21.8 19.2 20.2 — — — — — — 17.8 16.0 16.8 25.3 24.6 24.930 21.8 18.6 20.6 23.3 22.4 22.7 19.8 19.1 19.4 — — — — — — 18.3 16.3 16.9 25.3 25.0 25.131 22.1 20.2 21.2 23.1 22.2 22.6 21.3 19.1 20.2 — — — — — — 18.6 16.5 17.5 25.5 25.0 25.2

Month 25.5 16.2 19.8 25.4 20.1 23.1 26.1 15.8 20.6 e27 e12.8 e13.9 — — — 23.5 14.1 16.8 27.3 23.7 25.1

Table 13 85
Table 13.  Daily, monthly, and annual statistics for water temperature for U.S. Geological Survey stations in the drinking–water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in degrees Celsius. Max, maximum; Min, minimum; e, estimated; —, no data]

Month 

and 

date

Cambridge Reservoir, 

unnamed 

tributary 2, 

near Lexington 

(01104415)

Cambridge 

Reservoir near 

Kendal Green 

(01104430)

Hobbs Brook, unnamed tributary 1, 

near Kendal Green 

(01104433)

Stony Brook, unnamed 

tributary 1, 

near Waltham 

(01104455)

Stony Brook at 

Route 20 

at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, 

near Weston 

(01104475)

Fresh Pond 

gate house 

at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

September

1 22.8 20.1 21.7 25.6 22.4 24.3 21.3 18.5 19.9

—

—

—

—

—

— 18.2 16.4 17.4 26.1 25.0 25.5

2 21.0 18.7 19.9 25.7 25.1 25.4 21.0 16.6 18.7

—

—

—

—

—

— 17.9 15.4 16.6 26.4 24.9 25.6

3 20.4 18.2 19.3 25.9 25.4 25.6 19.6 16.3 17.9

—

—

—

—

—

— 17.3 15.3 16.2 26.2 24.9 25.5

4 19.9 17.3 18.6 26.2 25.4 25.8 19.3 15.5 17.0

—

—

—

—

—

— 16.8 14.8 15.7 25.8 24.8 25.2

5 19.0 16.1 17.6 26.0 25.5 25.7 17.7 14.5 16.0

—

—

—

—

—

— 16.1 13.8 14.9 25.3 24.3 24.8

6 18.8 15.0 16.9 25.7 25.2 25.5 17.7 13.3 15.4

—

—

—

—

—

— 15.9 13.1 14.4 25.4 24.4 24.9

7 19.3 15.8 17.6 25.5 25.0 25.3 18.8 13.9 16.2

—

—

—

—

—

— 16.5 13.5 14.9 26.0 24.5 25.1

8 20.1 16.5 18.3 25.5 24.9 25.2 19.5 14.8 17.1

—

—

—

—

—

— 17.0 14.2 15.5 27.0 24.7 25.5

9 18.7 16.9 18.0 25.6 25.1 25.3 17.6 15.8 16.8

—

—

—

—

—

— 16.0 14.8 15.4 25.8 24.3 25.0

10 17.4 14.5 16.2 25.7 25.0 25.3 16.1 13.7 15.0

—

—

—

—

—

— 15.1 13.0 14.3 25.2 23.8 24.4

11 16.9 12.5 15.0 25.3 24.4 24.8 16.4 12.6 14.4

—

—

—

—

—

— 14.9 11.8 13.4 25.1 23.5 24.3

12 20.0 15.1 17.6 24.9 24.2 24.5 19.7 14.6 16.8

—

—

—

—

—

— 17.4 13.8 15.4 25.5 23.9 24.7

13 20.8 17.0 18.9 25.1 24.6 24.8 20.1 16.6 18.3

—

—

—

—

—

— 17.4 15.2 16.1 25.4 24.7 25.0

14 21.4 18.1 19.8 24.9 24.4 24.7 21.0 17.5 19.1

—

—

—

—

—

— 18.0 15.5 16.6 26.1 24.7 25.3

15 23.0 18.9 20.8 25.1 24.6 24.8 20.5 18.2 19.7

—

—

—

—

—

— 20.7 16.3 17.6 26.0 25.2 25.6

16 21.1 18.2 19.6 25.4 24.8 25.1 19.6 17.7 18.6

—

—

—

—

—

— 17.4 16.2 16.7 25.4 24.6 25.1

17 19.1 17.7 18.0 25.2 24.5 24.8 18.1 17.1 17.7

—

—

—

—

—

— 16.4 15.7 16.0 24.7 24.2 24.4

18 18.8 17.2 18.4 24.8 24.3 24.6 18.4 16.5 17.4

—

—

—

—

—

— 16.6 15.4 15.9 25.9 24.2 25.0

19 18.1 15.9 17.2 24.8 24.1 24.4 19.0 14.7 16.7

—

—

—

—

—

— 16.7 14.3 15.5 26.5 24.4 25.3

20 18.0 16.5 17.2 24.5 24.1 24.3 18.2 15.4 16.8

—

—

—

—

—

— 16.7 14.9 15.8 25.8 25.0 25.2

21 18.3 16.1 17.3 24.3 23.8 24.1 18.2 15.0 16.6

—

—

—

—

—

— 16.7 14.7 15.7 25.2 24.2 24.8

22 18.8 15.7 17.3 24.2 23.6 23.9 18.5 14.4 16.4

—

—

—

—

—

— 17.0 14.3 15.6 25.5 24.2 24.8

23 18.4 16.0 17.4 24.4 23.6 23.9 18.2 15.7 16.9

—

—

—

—

—

— 16.7 14.8 15.8 25.1 24.3 24.8

24 16.2 13.2 14.9 23.9 23.0 23.5 15.7 12.9 14.1

—

—

—

—

—

— 14.8 11.9 13.5 24.6 23.8 24.1

25 14.8 11.8 13.8 23.5 22.7 23.0 14.8 11.7 13.3

—

—

—

—

—

— 13.5 10.5 12.2 24.2 23.4 23.8

26 17.2 14.6 16.1 22.9 22.3 22.6 17.1 14.8 16.0

—

—

—

—

—

— 15.7 13.4 14.7 24.0 23.4 23.8

27 17.9 14.0 16.5 23.2 22.2 22.6 17.4 13.8 16.4

—

—

—

—

—

— 16.0 13.1 15.2 24.8 23.4 24.1

28 16.0 12.2 14.2 22.6 21.7 22.1 15.6 12.3 13.9

—

—

—

—

—

— 14.2 11.4 13.0 24.6 23.7 24.1

29 18.4 13.7 15.7 21.8 21.3 21.6 18.0 13.5 15.0

—

—

—

—

—

— 17.5 12.6 14.0 24.3 23.7 24.1

30 15.3 12.3 13.4 21.7 20.6 21.1 14.5 12.4 13.5

—

—

—

—

—

— 12.7 10.7 11.7 24.4 23.1 23.7

Month 23.0 11.8 17.4 26.2 20.6 24.3 21.3 11.7 16.6

—

—

—

—

—

— 20.7 10.5 15.2 27.0 23.1 24.8

Year 25.5 –.7 10.2 26.2 .8 11.9 27.6 e–.5 e11.1

—

—

— e24.7 –.1 e7.5 e23.5 e.2 e10.3 28.5 .4 13.3

Results Good Good Good1 Good Good2 Excellent2 Good 1Records between 06/01/05 and 09/30/05 are rated as poor.

2Records that are estimated are rated as poor.

86 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

October

1 1,340 1,170 1,260 730 724 727 1,310 1,120 1,170 966 485 781 333 296 314 231 223 227 580 576 5782 1,570 1,080 1,370 730 721 726 1,490 1,170 1,280 992 607 957 398 332 339 238 227 230 579 553 5753 1,570 1,160 1,330 731 719 726 1,540 1,120 1,250 1,050 631 962 357 333 347 247 235 240 556 549 5534 1,590 1,450 1,530 728 722 725 1,480 1,130 1,290 1,080 1,040 1,060 412 355 384 736 237 312 561 555 5585 1,720 1,500 1,640 726 720 723 1,640 1,480 1,540 1,120 1,080 1,100 404 396 400 278 230 239 560 556 5586 1,770 1,700 1,730 725 716 721 1,780 1,640 1,710 1,130 1,120 1,120 406 397 403 235 226 229 563 557 5607 1,920 1,760 1,830 724 717 720 1,820 1,780 1,790 1,140 1,120 1,130 399 393 396 248 221 228 566 560 5638 1,890 1,780 1,820 723 715 719 1,870 1,820 1,840 1,140 1,140 1,140 435 396 402 264 248 257 576 565 5709 1,940 1,810 1,870 722 716 718 1,910 1,870 1,890 1,140 1,130 1,140 535 435 511 267 259 263 583 576 580

10 2,000 1,900 1,950 720 716 718 1,930 1,890 1,910 1,130 1,100 1,110 558 535 546 276 267 272 589 583 58611 2,050 1,840 1,980 722 711 719 1,960 1,930 1,950 1,140 1,130 1,130 566 527 557 282 275 279 593 587 59012 2,150 1,810 2,040 724 714 718 1,980 1,960 1,960 1,140 999 1,100 527 451 473 282 278 279 592 590 59113 2,150 1,960 2,050 720 711 717 1,970 1,940 1,960 1,150 1,130 1,130 456 451 454 285 271 278 598 590 59314 2,110 2,050 2,080 718 708 716 1,940 1,860 1,900 1,150 1,140 1,140 519 441 456 278 272 275 603 593 59815 2,200 791 1,970 718 709 715 1,870 700 1,760 1,150 124 800 603 432 537 279 195 267 610 600 60616 1,220 218 751 714 703 711 700 120 290 970 43 586 486 333 443 239 141 222 611 608 61017 1,590 1,220 1,410 713 700 710 1,050 519 792 1,070 970 1,030 435 425 432 244 238 241 611 609 61018 1,770 1,590 1,670 713 704 711 1,440 1,050 1,260 1,110 1,070 1,090 450 424 439 248 239 245 609 604 60719 1,770 589 1,090 712 701 709 1,520 289 810 1,110 120 424 471 333 383 249 206 227 605 601 60320 1,490 922 1,260 710 699 706 864 312 563 995 777 916 384 372 379 242 228 236 601 596 59921 1,660 1,490 1,580 706 702 704 1,330 864 1,110 1,060 995 1,030 378 373 376 248 240 244 597 591 59422 1,750 1,660 1,690 704 698 702 1,570 1,330 1,450 1,080 1,060 1,070 386 377 382 252 247 250 592 586 58923 1,830 1,740 1,770 701 689 699 1,740 1,570 1,660 1,100 1,060 1,090 395 385 392 255 250 253 586 583 58524 1,910 1,800 1,850 699 695 697 1,820 1,740 1,780 1,110 1,100 1,100 440 395 403 257 253 255 583 578 58025 1,960 1,900 1,930 697 686 695 1,860 1,820 1,840 1,110 986 1,090 491 440 471 259 257 258 578 572 57526 1,980 1,910 1,950 704 692 697 1,940 1,860 1,900 1,140 1,090 1,120 499 486 490 262 258 259 572 558 56227 2,030 1,980 2,000 704 687 697 1,990 1,940 1,950 1,130 1,130 1,130 503 499 501 263 261 262 559 556 55828 2,050 2,010 2,020 698 686 695 2,030 1,990 2,010 1,140 1,130 1,130 509 503 507 268 263 267 557 554 55629 2,090 2,050 2,080 697 686 694 2,040 2,000 2,020 1,130 1,130 1,130 521 509 515 268 264 266 556 554 55530 2,100 2,070 2,090 695 686 692 2,060 2,040 2,050 1,130 1,000 1,080 570 516 531 269 263 265 554 552 55331 2,070 2,010 2,030 696 679 692 2,050 2,020 2,040 1,120 1,050 1,100 575 559 570 277 266 270 552 548 551

Month 2,200 218 1,730 731 679 710 2,060 120 1,570 1,150 43 1,030 603 296 443 736 141 255 611 548 579

Table 14 87
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

November

1 2,110 2,030 2,080 697 677 694 2,020 1,990 2,010 1,130 1,120 1,120 586 560 575 278 268 275 548 543 5462 2,190 2,110 2,150 696 685 693 1,990 1,930 1,950 1,130 1,120 1,120 590 586 589 275 266 269 544 540 5423 2,190 2,170 2,180 697 684 693 2,010 1,930 1,960 1,120 1,090 1,110 588 572 580 273 267 270 541 536 5384 2,210 414 2,040 696 681 689 2,040 834 1,930 1,120 52 932 611 415 570 275 169 262 537 535 5365 1,320 301 885 691 678 687 834 224 372 971 70 700 518 415 506 251 179 240 535 530 5336 1,620 1,320 1,500 688 676 685 832 497 622 1,050 971 1,020 511 506 509 254 251 252 531 529 5307 1,730 1,620 1,670 688 676 685 1,130 832 961 1,070 1,050 1,060 527 508 519 258 253 255 532 528 5308 1,870 1,730 1,810 690 673 685 1,590 1,130 1,420 1,100 1,070 1,080 548 527 538 265 256 259 536 532 5349 1,940 1,870 1,900 687 675 683 1,780 1,590 1,680 1,110 1,100 1,110 560 548 554 263 259 261 539 535 537

10 2,000 1,470 1,830 684 673 681 1,890 1,780 1,840 1,110 1,110 1,110 571 560 568 265 262 263 541 538 54011 2,000 1,880 1,920 683 670 680 1,950 1,880 1,910 1,110 1,100 1,110 574 570 572 266 264 265 541 537 53912 4,820 1,760 2,270 682 669 678 2,020 1,940 1,980 11,000 879 2,660 755 573 600 266 251 262 537 533 53513 10,800 4,820 7,420 675 662 670 3,820 2,020 3,030 22,300 2,450 11,000 1,150 615 813 266 251 256 535 532 53314 6,880 4,960 6,200 670 661 667 5,980 3,650 5,020 2,450 1,250 1,580 616 571 591 265 258 262 534 531 53315 4,960 2,810 3,850 672 659 667 6,080 4,240 5,650 1,250 799 1,070 578 560 568 266 261 263 534 532 53316 2,810 2,230 2,360 669 662 665 4,240 2,190 2,890 1,030 789 929 567 558 563 262 259 261 534 531 53317 2,260 2,140 2,200 668 663 665 2,190 1,920 2,000 1,040 630 907 567 538 556 262 259 260 535 531 53318 2,190 1,990 2,060 668 663 666 1,920 1,660 1,780 1,030 923 977 538 508 528 262 256 259 534 532 53319 2,020 1,950 1,970 674 661 668 1,680 1,570 1,610 1,070 1,030 1,060 508 472 494

—

— e261 534 531 532

20 2,230 1,720 2,060 671 660 668 2,400 1,590 1,740 4,690 1,070 1,260 840 461 484

—

— e262 533 531 532

21 2,910 2,000 2,360 673 662 668 2,060 1,700 1,960 2,300 1,030 1,230 579 461 475

—

— e261 533 531 532

22 2,000 1,950 1,970 696 666 680 1,890 1,770 1,820 1,290 745 1,190 463 452 460

—

— e261 532 531 532

23 2,270 1,950 2,160 694 690 692 1,980 1,830 1,910 1,310 1,280 1,300 452 408 422 279 274 e261 532 531 53124 3,590 1,570 2,260 694 689 692 2,110 1,510 1,970 1,670 312 1,130 560 386 413 283 233 e260 533 530 53225 2,060 1,000 1,360 695 686 693 1,570 569 900 1,020 162 673 490 354 391 272 229 258 533 530 53226 1,750 1,310 1,540 693 688 691 936 735 793 1,160 755 1,070 379 372 375 264 261 263 531 529 53027 1,890 1,750 1,840 690 685 688 1,410 936 1,170 1,200 1,160 1,180 383 375 380 267 264 265 531 529 53028 1,880 297 1,360 691 669 686 1,560 137 1,060 1,210 41 792 478 218 353 268 141 239 531 527 52929 1,220 378 955 686 679 683 972 222 555 786 292 612 346 316 333 238 207 223 528 526 52730 1,360 1,140 1,300 685 681 683 1,490 972 1,250 855 786 830 325 317 321 249 238 243 527 524 526

Month 10,800 297 2,250 697 659 681 6,080 137 1,860 22,300 41 1,430 1,150 218 507 e283 e141 e258 548 524 533

88 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

December

1 1,410 308 871 686 677 682 1,550 221 931 950 81 528 349 249 307 252 179 230 527 524 5252 1,180 785 1,050 681 677 679 1,160 425 729 772 600 711 319 303 312 243 230 237 527 525 5263 1,290 1,170 1,230 680 676 678 1,630 1,160 1,410 812 761 787 309 302 305 252 243 247 526 524 5254 1,390 1,290 1,340 678 673 675 1,840 1,630 1,730 838 812 827 314 285 306 258 252 255 525 523 5245 1,500 1,380 1,430 734 673 686 1,950 1,840 1,890 856 831 844 319 287 308 261 258 259 526 523 5246 1,550 1,500 1,530 733 726 730 2,080 1,930 2,010 1,970 838 954 352 308 323 265 260 263 525 522 5247 6,180 497 3,040 730 716 724 4,910 332 2,230 18,500 157 3,840 1,370 307 534 277 180 239 522 521 5228 1,150 496 917 722 716 719 1,080 336 714 646 295 528 328 306 318 231 204 218 521 519 5219 1,230 1,140 1,190 724 717 721 1,710 1,080 1,460 705 646 680 307 287 292 239 231 235 520 518 519

10 1,240 403 1,030 724 713 721 1,860 388 1,450 775 96 497 309 267 298 239 169 229 520 519 51911 917 327 669 720 714 716 996 197 516 607 90 468 293 245 284 221 153 206 519 517 51812 1,100 917 1,020 718 714 716 1,620 996 1,380 686 607 650 284 276 280 233 221 227 518 516 51713 1,200 1,100 1,140 717 713 716 1,870 1,620 1,740 724 686 701 306 283 294 238 233 235 518 516 51714 1,260 1,150 1,230 717 713 715 2,050 1,870 1,960 777 724 753 309 299 305 244 238 241 518 515 51715 1,340 1,260 1,300 717 710 714 2,140 2,050 2,090 808 777 790 328 307 317 250 244 246 516 514 51516 1,370 1,210 1,330 714 710 712 2,180 2,130 2,160 828 806 817 341 327 337 254 250 252 515 513 51417 1,410 1,330 1,360 714 709 712 2,210 2,140 2,170 844 807 824 344 339 341 257 253 254 514 512 51318 1,460 1,400 1,430 715 710 713 2,300 2,210 2,260 871 843 859 348 340 345 259 254 257 513 510 51219 1,450 1,380 1,430 714 709 712 2,390 2,270 2,300 2,530 857 1,000 423 346 354 285 256 259 512 510 51120 6,080 1,450 4,730 713 707 711 4,060 2,310 2,960 21,600 1,530 7,750 1,050 377 606 286 252 257 511 508 51021 3,930 2,040 2,520 714 708 711 5,460 4,060 4,890 1,530 1,140 1,280 378 364 370 264 260 262 510 507 50822 2,580 1,930 2,110 717 710 713 4,430 3,830 4,120 2,020 992 1,310 410 367 377 275 261 265 508 505 50723 3,890 663 2,320 715 694 711 4,580 428 3,650 4,800 168 1,810 728 306 400 319 145 258 508 505 50724 1,150 617 952 709 697 703 1,530 422 976 676 323 e530 356 289 312 229 209 222 507 503 50525 1,220 1,140 1,190 710 700 703 2,100 1,530 1,860 719 676 e655 289 279 284 233 229 231 504 501 50326 2,380 1,220 1,610 711 703 708 — — e1,930 — — e2,720 579 280 346 238 232 236 503 499 50127 2,310 1,500 1,900 706 698 702 — — e1,970 — — e939 419 322 343 244 234 239 503 500 50128 2,070 1,440 1,630 703 692 699 — — e1,870 — — e708 359 321 329 — — e240 500 496 49829 1,640 1,410 1,490 694 668 683 — — e1,810 — — e1,050 454 359 416 — — e240 497 495 49630 1,620 1,440 1,510 676 661 669 — — e1,750 — — e1,010 465 438 450 — — e241 495 492 49431 2,360 1,430 1,670 673 657 667 — — e1,730 — — e957 519 458 475 — — e240 494 492 493

Month 6,180 308 1,550 734 657 704 e5,460 e197 e1,960 e21,600 e81 e1,220 1,370 245 351 e319 e145 e243 527 492 512

Table 14 89
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

January

1 2,250 1,230 1,510 679 661 671

—

— e1,570

—

— e1,010 473 447 455

—

— e241 493 490 492

2 1,580 1,230 1,310 677 662 670

—

— e1,470

—

— e1,130 473 443 447

—

— e241 492 490 491

3 1,630 1,100 1,320 676 661 670

—

— e1,390

—

— e815 486 429 441

—

— e242 491 489 490

4 1,820 847 1,030 675 663 670 2,640 767 1,270 787 278 e957 473 398 416 251 228 242 489 486 4885 2,370 1,020 1,590 673 661 668 3,090 1,320 2,010 6,090 787 1,860 591 416 443 336 251 268 488 485 4876 8,850 1,540 3,960 675 660 668 7,560 2,760 3,600 17,300 1,040 5,890 1,720 428 648 358 250 277 488 486 4877 6,050 1,930 3,070 671 656 664 7,550 2,950 4,740 3,870 1,210 1,860 524 463 477 358 282 308 488 485 4878 5,610 1,500 2,340 669 654 663 3,490 2,610 2,850 11,800 1,110 4,680 1,170 467 575 283 263 271 487 483 4869 5,830 2,220 3,410 671 654 663 6,380 3,490 5,480 7,950 1,800 3,340 572 476 496 292 270 279 485 483 485

10 2,730 1,780 2,170 673 659 667 6,560 4,130 5,610 1,800 1,440 1,550 500 476 484 281 275 279 484 482 48311 2,280 1,630 1,780 674 660 668 4,130 3,520 3,880 1,440 1,220 1,310 518 483 485 280 276 278 484 481 48312 11,800 1,630 5,370 668 650 661 7,180 3,490 4,350 16,200 1,150 5,750 1,240 510 696 778 273 360 483 482 48313 2,980 1,720 2,000 659 645 652 3,790 2,100 2,840 1,150 526 917 519 491 503 328 280 296 482 481 48214 1,760 615 915 674 653 664 2,100 745 1,040 781 296 572 501 375 445 286 231 258 483 480 48115 1,040 818 961 672 655 663 2,470 985 1,860 831 781 820 375 339 345 259 249 255 481 479 48016 1,190 1,040 1,100 668 655 663 2,600 2,470 2,550 5,080 831 989 388 339 344 265 258 263 481 479 48017 2,080 1,190 1,800 675 659 667 3,990 2,600 2,850 5,460 909 1,870 443 353 374 277 263 269 481 478 47918 1,550 1,420 1,450 681 670 676 4,190 3,380 3,740 968 915 948 395 359 378 282 274 277 480 477 47919 3,050 1,420 1,520 686 675 680 3,380 2,950 3,170 7,540 917 1,930 544 395 420 285 266 279 478 475 47620 5,770 2,360 3,900 687 678 682 4,300 2,970 3,260 7,850 3,110 4,420 561 410 462 292 264 277 475 473 47421 2,360 1,760 1,910 689 679 683 5,530 4,300 4,900 3,110 981 1,790 421 410 415 284 277 280 477 473 47422 1,770 1,600 1,710 699 685 693 4,310 3,370 3,810 1,040 974 995 437 421 430 282 269 279 475 474 47523 1,810 1,520 1,690 707 695 702 3,400 3,290 3,340 1,040 933 965 452 429 442 271 262 268 475 474 47524 1,650 1,550 1,580 718 704 711 3,290 3,020 3,150 1,620 944 1,060 443 429 433 283 270 273 475 474 47425 1,700 1,560 1,620 726 714 720 3,020 2,430 2,810 1,480 934 1,050 441 432 434 281 273 275 476 473 47526 2,050 1,600 1,700 729 719 725 2,810 2,470 2,630 1,150 934 997 441 432 435 274 270 272 477 476 47627 2,420 2,050 2,320 737 723 729 2,890 2,750 2,820 2,280 960 1,370 459 437 445 274 272 273 477 476 47728 2,230 1,790 1,970 742 730 736 3,130 2,850 2,980 1,080 951 987 454 444 449 301 273 276 479 476 47729 1,790 1,690 1,730 749 739 744 3,190 3,030 3,120 1,530 951 1,110 464 453 458 341 273 283 479 477 47830 1,800 1,620 1,710 755 745 750 3,050 2,960 2,990 1,930 984 1,300 472 456 461 321 272 280 479 478 47831 1,800 1,660 1,720 760 748 754 3,060 2,840 2,960 1,280 971 1,070 469 459 463 285 273 275 479 478 479

Month 11,800 615 2,010 760 645 687 e7,560 e745 e3,070 e17,300 e278 e1,780 1,720 339 458 e778 e228 e274 493 473 481

90 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

February

1 1,680 1,610 1,650 768 756 762 3,050 2,800 2,940 1,280 977 1,060 477 466 471 284 274 276 481 478 4802 1,650 1,600 1,620 770 761 766 2,870 2,690 2,800 1,410 985 1,120 483 472 476 293 275 279 481 480 4803 3,500 1,570 1,860 772 765 769 3,220 2,660 2,780 8,940 943 2,870 708 476 519 723 275 311 481 480 4804 10,400 3,500 7,390 778 765 773 7,100 3,220 5,540 15,600 2,170 7,950 835 505 638 545 280 355 482 480 4815 5,370 2,720 3,580 785 773 779 7,100 3,500 5,150 2,170 1,240 1,720 532 497 509 358 293 314 483 481 4826 2,820 2,190 2,440 787 722 781 3,500 2,800 3,020 1,320 1,170 1,210 516 505 508 307 294 299 483 482 4827 2,320 2,080 2,190 785 724 733 2,900 2,740 2,800 1,220 1,150 1,190 585 500 529 303 291 295 483 482 4838 2,160 2,000 2,070 743 733 738 2,920 2,780 2,850 1,210 1,140 1,190 534 526 529 301 289 292 484 482 4849 2,200 1,910 2,060 744 737 740 2,930 2,610 2,770 1,240 1,070 1,150 535 526 530 308 288 295 485 484 484

10 3,010 1,090 1,750 745 737 741 2,620 951 1,590 8,880 442 2,580 899 509 605 370 273 293 487 484 48511 4,450 2,200 3,320 752 741 747 6,530 1,660 4,280 10,300 3,340 6,070 872 494 576 506 275 315 487 485 48612 2,200 1,650 1,810 760 749 755 5,690 3,370 4,030 3,340 1,140 2,370 504 495 498 291 286 288 486 485 48513 1,750 1,690 1,710 761 756 758 3,370 2,780 2,960 1,140 1,070 1,120 514 503 509 288 286 287 486 484 48514 1,760 1,700 1,720 763 756 759 2,880 2,810 2,840 2,930 1,070 1,160 634 513 522 305 286 287 486 485 48515 3,800 935 1,510 767 759 763 2,850 1,080 1,560 3,300 452 955 781 464 517 331 247 266 488 485 48716 1,230 741 1,090 774 764 769 2,300 1,310 1,870 1,140 483 836 582 415 448 265 229 258 489 487 48817 1,160 761 1,020 781 772 776 2,120 1,070 1,560 876 629 813 437 407 419 261 247 257 489 486 48818 1,310 1,160 1,240 787 778 783 2,400 2,120 2,280 921 876 898 424 407 414 268 260 264 489 487 48819 1,420 1,310 1,380 791 781 786 2,430 2,370 2,410 958 921 937 454 424 440 277 263 271 489 484 48720 1,500 1,420 1,470 801 790 795 2,530 2,420 2,470 960 937 948 476 454 467 269 255 262 484 476 48021 5,690 1,490 3,140 805 797 801 3,080 2,520 2,570 9,460 950 4,720 869 475 601 257 246 252 476 470 47322 5,600 2,640 3,760 809 801 806 6,610 3,080 5,840 8,530 2,820 4,620 626 497 537 405 248 273 470 467 46823 2,640 2,090 2,270 813 808 810 6,430 4,950 5,810 3,090 1,410 2,430 541 497 508 402 259 276 467 465 46624 2,170 1,880 2,000 816 811 813 4,950 3,480 3,830 2,350 1,010 1,110 599 507 519 277 268 273 465 464 46525 8,060 1,890 5,390 819 812 814 3,640 3,280 3,430 9,640 2,350 5,230 881 533 628 438 276 309 465 464 46526 4,320 2,200 2,910 822 815 818 5,760 3,550 4,770 2,480 1,990 2,190 564 516 541 290 286 288 465 464 46427 2,210 1,980 2,070 826 817 821 5,180 3,920 4,410 2,210 1,930 2,060 558 543 550 292 287 288 466 465 46628 1,980 1,930 1,960 828 823 825 3,920 3,480 3,650 11,800 1,360 2,300 976 556 582 289 275 286 466 465 466

Month 10,400 741 2,370 828 722 778 7,100 951 3,310 15,600 442 2,240 976 407 521 723 229 286 489 464 479

Table 14 91
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

March

1 7,950 1,950 4,670 830 757 794 5,720 3,320 3,770 13,000 2,950 6,340 1,090 526 673 589 274 330 468 465 4662 6,990 3,580 5,470 763 756 759 6,970 5,660 6,430 3,400 1,960 2,670 551 449 479 463 294 323 469 466 4683 3,580 2,550 2,900 764 757 760 6,030 4,490 5,130 1,960 1,710 1,780 458 444 451 297 292 294 470 468 4694 2,550 2,260 2,370 762 756 759 4,490 3,620 3,970 1,760 1,650 1,710 487 429 457 294 290 292 470 468 4695 2,330 2,150 2,220 761 754 757 3,700 3,310 3,520 1,650 1,550 1,610 480 441 463 309 289 293 472 469 4716 2,340 2,160 2,250 761 754 758 3,470 3,300 3,400 1,560 1,460 1,520 464 459 461 297 287 290 472 470 4717 2,570 2,160 2,280 760 754 757 3,370 2,160 3,130 1,460 949 1,280 481 460 467 315 286 296 472 471 4718 3,920 1,950 2,910 759 751 755 3,640 2,040 2,360 4,900 925 2,480 1,250 468 583 566 289 326 478 470 4729 4,340 2,430 3,100 760 752 756 4,360 2,900 3,540 8,160 2,890 4,540 797 413 548 339 283 298 475 472 473

10 3,310 2,230 2,620 763 756 759 5,450 4,360 5,060 3,070 2,150 2,400 489 444 471 348 295 303 474 471 47211 3,440 2,100 2,550 765 752 757 4,870 4,320 4,510 7,320 2,180 3,280 884 460 522 334 294 300 473 472 47312 16,100 2,540 7,080 754 746 750 7,720 4,270 5,710 12,200 2,490 8,340 1,770 480 805 363 281 292 475 473 47313 16,800 4,960 10,400 752 741 748 9,700 6,580 8,560 11,400 6,070 9,050 997 528 636 454 288 341 475 473 47414 4,960 3,260 3,780 749 740 744 6,580 3,660 4,820 6,070 4,210 4,630 535 491 511 328 314 319 475 474 47415 3,570 2,910 3,210 755 744 749 3,700 2,440 3,340 4,310 3,580 4,020 525 498 514 319 314 317 475 474 47516 2,950 2,480 2,730 757 749 753 3,260 2,420 2,720 3,580 2,790 3,170 530 492 511 317 313 315 477 474 47617 2,490 2,240 2,400 760 751 755 3,240 2,680 2,850 2,790 1,970 2,420 513 488 500 316 312 314 478 474 47618 2,280 2,060 2,210 758 743 752 3,190 2,830 3,060 1,970 1,380 1,640 506 487 497 316 311 313 477 474 47619 2,060 1,810 2,000 749 731 740 3,090 2,790 2,970 1,380 1,230 1,280 500 446 486 314 307 311 478 475 47720 1,880 1,660 1,820 733 720 727 3,060 2,840 2,980 1,230 1,180 1,190 501 487 494 313 305 309 479 475 47821 1,740 1,620 1,690 772 709 721 3,060 2,830 2,970 1,180 1,130 1,140 497 461 485 309 304 307 480 477 47822 1,690 1,410 1,590 770 703 746 3,030 2,910 2,980 1,130 1,070 1,110 490 457 476 308 298 305 479 477 47823 1,630 1,410 1,550 759 747 754 3,000 2,770 2,870 1,100 1,050 1,070 472 461 468 302 296 300 481 478 48024 10,700 1,620 5,220 756 739 747 10,300 2,710 5,170 12,300 1,100 10,600 1,600 466 737 328 295 311 481 480 48125 2,510 1,760 2,030 746 729 738 3,330 2,510 2,900 8,240 3,800 5,160 541 518 531 314 301 309 482 479 48126 1,850 1,760 1,820 739 714 729 3,260 2,940 3,050 3,800 3,140 3,380 536 514 527 305 298 301 483 479 48127 1,880 1,730 1,820 727 712 721 3,270 3,050 3,180 3,180 2,930 3,080 533 518 527 298 291 296 483 481 48228 2,770 914 1,630 721 695 710 3,170 705 2,010 2,930 374 1,530 599 475 521 293 218 266 483 482 48329 1,400 929 1,160 702 684 692 806 715 738 1,070 412 837 508 358 401 284 209 258 484 482 48330 1,610 1,400 1,530 721 693 708 2,050 806 1,320 1,190 1,070 1,130 411 356 385 297 253 291 485 480 48231 1,780 1,610 1,680 715 655 690 2,420 2,040 2,260 1,280 1,190 1,230 430 409 421 302 271 295 485 480 482

Month 16,800 914 2,930 830 655 743 10,300 705 3,590 13,000 374 3,080 1,770 356 516 589 209 304 485 465 476

92 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

April

1 1,840 1,710 1,760 699 613 676 2,440 2,310 2,390 1,320 1,280 1,290 437 422 429 297 289 292 484 480 4822 1,980 675 1,320 668 585 636 2,380 409 1,300 1,670 219 874 459 405 424 298 244 278 484 482 4833 1,530 502 1,090 926 658 776 1,230 340 710 1,090 165 787 448 372 406 288 210 268 485 479 4814 1,690 1,400 1,550 823 791 807 1,970 966 1,410 1,200 1,090 1,140 488 448 474 290 284 287 481 478 4805 1,830 1,660 1,740 791 737 760 2,260 1,970 2,150 1,250 1,200 1,220 496 473 489 292 274 288 481 478 4796 2,080 1,800 1,870 750 729 740 2,850 2,260 2,400 1,280 1,240 1,260 483 473 478 298 286 293 481 477 4797 1,950 1,860 1,910 747 735 739 2,950 2,430 2,610 1,310 1,280 1,290 497 483 493 299 293 297 482 476 4788 2,120 1,020 1,570 776 734 750 2,450 762 1,400 1,540 433 1,070 544 479 499 296 271 287 479 470 4759 1,990 1,840 1,910 784 745 766 2,190 1,630 1,960 1,330 1,280 1,310 525 512 519 300 294 297 478 474 476

10 2,080 1,950 2,010 778 749 764 2,390 2,190 2,310 1,360 1,330 1,340 533 524 529 306 300 303 476 470 47311 2,140 2,050 2,100 791 761 770 2,500 2,040 2,430 1,380 1,360 1,370 541 533 535 312 305 308 480 469 47512 2,200 2,050 2,130 785 758 769 2,600 2,090 2,520 1,390 1,360 1,380 548 539 544 313 309 311 482 474 47613 2,210 2,110 2,160 788 762 772 2,620 2,530 2,570 1,380 1,350 1,370 552 545 548 314 311 313 478 475 47714 2,290 2,180 2,220 784 760 770 2,660 2,130 2,580 1,420 1,360 1,380 562 551 556 314 311 313 480 476 47715 2,390 2,250 2,300 778 761 769 2,740 2,630 2,680 1,440 1,400 1,420 563 554 559 314 312 313 479 477 47816 2,420 2,310 2,360 780 763 772 2,770 2,680 2,730 1,460 1,420 1,440 566 559 562 316 313 314 481 477 47917 2,450 2,350 2,400 790 768 778 2,800 2,720 2,760 1,460 1,420 1,440 571 552 564 316 313 315 480 470 47918 2,520 2,400 2,460 793 781 786 2,810 2,750 2,790 1,490 1,450 1,460 571 553 565 319 315 317 482 471 47919 2,570 2,470 2,530 789 775 781 2,830 2,790 2,820 1,500 1,470 1,480 573 564 569 319 315 317 484 474 48120 2,580 2,060 2,530 786 773 779 2,850 2,380 2,810 1,930 1,490 1,520 636 564 571 323 317 319 483 481 48221 3,020 1,690 2,130 789 776 783 2,810 1,420 1,850 1,820 661 1,280 605 558 572 321 309 316 484 478 48222 2,530 2,330 2,440 788 776 782 2,220 1,490 1,860 1,530 1,480 1,500 613 571 582 318 313 316 486 483 48423 2,990 858 1,940 781 775 778 2,320 611 1,670 1,510 353 1,060 646 488 568 313 282 302 488 484 48524 1,820 738 1,340 777 771 774 1,020 459 754 1,240 303 859 575 463 510 300 252 279 485 481 48325 2,080 1,050 1,670 775 769 772 1,450 846 1,100 1,280 570 1,110 520 486 494 289 269 282 483 480 48126 2,390 2,010 2,160 773 767 770 1,990 1,200 1,600 1,350 1,280 1,320 522 501 514 297 289 293 483 480 48127 2,410 829 1,830 772 766 769 2,110 568 1,660 1,360 365 1,000 540 474 519 300 256 287 484 481 48328 2,040 1,490 1,790 770 764 767 1,380 666 1,140 1,270 921 1,130 519 510 514 288 278 283 484 481 48329 2,270 2,040 2,150 769 764 766 2,050 1,380 1,700 1,350 1,270 1,310 531 519 525 296 287 292 485 483 48430 2,710 760 2,050 769 763 767 2,230 938 2,050 1,360 333 1,090 559 458 528 297 248 290 487 484 485

Month 3,020 502 1,980 926 585 763 2,950 340 2,020 1,930 165 1,250 646 372 521 323 210 299 488 469 480

Table 14 93
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

May

1 1,800 764 1,370 767 761 764 1,100 645 840 1,220 552 998 530 501 513 283 264 278 487 483 4852 2,080 1,750 1,940 764 759 762 1,710 926 1,280 1,310 1,220 1,280 520 510 515 292 283 288 488 485 4863 2,230 1,940 2,060 767 759 762 1,960 1,650 1,840 1,350 997 1,260 535 516 526 296 286 293 488 487 4884 2,340 2,180 2,250 768 754 764 2,080 1,830 1,920 1,380 1,350 1,360 548 533 542 298 296 297 490 488 4895 2,440 2,310 2,370 774 762 768 2,360 2,070 2,200 1,420 1,380 1,390 562 546 554 301 297 299 491 489 4906 2,490 2,410 2,450 768 762 765 2,590 2,300 2,440 1,430 1,420 1,420 561 555 558 303 299 301 493 491 4927 2,480 917 1,520 767 754 760 2,610 608 1,480 1,430 459 747 584 497 530 303 265 279 493 490 4918 2,030 1,140 1,730 756 752 754 1,310 670 957 1,290 900 1,190 518 499 506 285 275 282 492 491 4929 2,280 2,030 2,120 756 750 753 1,940 1,310 1,630 1,350 1,260 1,320 527 505 517 290 285 287 493 491 492

10 2,430 2,260 2,340 767 751 758 2,230 1,930 2,050 1,400 1,350 1,370 543 527 534 295 289 291 494 492 49311 2,550 2,390 2,470 763 749 753 2,310 2,200 2,250 1,440 1,400 1,420 559 542 552 299 292 296 496 492 49312 2,680 2,530 2,590 762 748 756 2,470 2,290 2,350 1,500 1,440 1,460 564 556 560 302 296 299 498 495 49613 2,740 2,590 2,680 765 755 759 2,570 2,460 2,520 1,520 1,490 1,500 573 562 566 308 300 302 499 497 49814 2,770 2,660 2,720 769 752 759 2,590 2,530 2,570 1,530 1,510 1,520 577 570 573 304 302 303 500 498 49915 2,770 2,710 2,740 762 754 758 2,620 2,520 2,590 1,560 1,530 1,540 574 566 569 310 304 305 501 499 50016 3,650 1,470 2,240 758 753 755 2,620 758 1,250 1,560 615 1,170 676 521 568 306 284 295 503 498 50017 2,700 2,410 2,560 757 721 739 1,950 1,200 1,640 1,520 1,440 1,480 574 562 567 303 298 300 503 501 50218 3,780 1,790 2,600 723 713 719 2,270 1,950 2,110 1,560 1,520 1,550 576 565 569 337 301 310 504 502 50319 2,610 1,990 2,370 721 710 715 2,390 2,080 2,290 1,590 1,440 1,540 596 571 576 338 301 306 506 503 50420 2,770 2,610 2,680 715 707 712 2,440 1,960 2,320 1,630 1,590 1,600 580 575 577 314 303 306 508 505 50621 2,940 2,090 2,780 712 705 709 2,530 2,220 2,480 1,640 1,430 1,610 579 564 574 306 303 305 508 505 50722 2,690 802 1,760 710 699 705 2,330 673 1,180 1,540 655 1,210 611 502 553 303 279 295 509 505 50823 2,840 1,040 2,340 705 697 702 1,970 1,220 1,560 1,830 704 1,500 626 538 556 300 279 297 509 506 50824 1,220 506 868 700 684 693 1,800 436 710 1,200 502 847 559 464 518 291 246 277 508 502 50625 1,110 427 731 689 678 683 813 315 514 1,030 491 743 475 407 455 256 214 243 503 499 50226 1,050 341 746 681 654 668 1,310 279 675 1,100 472 896 424 371 415 228 171 216 501 497 49927 1,460 839 1,200 673 652 664 1,530 849 1,160 1,310 1,040 1,220 465 420 444 233 218 227 502 497 49928 1,740 1,460 1,580 671 659 665 1,930 1,530 1,770 1,480 1,090 1,350 506 465 481 249 233 241 502 500 50129 1,930 1,610 1,760 685 659 673 2,020 1,540 1,740 1,420 759 1,250 526 482 508 252 239 247 504 499 50130 1,980 1,800 1,880 696 677 686

—

— e1,880 1,470 1,390 1,440 529 516 521 255 249 252 503 499 501

31 2,080 1,970 2,020 690 683 686

—

— e2,020 1,510 1,470 1,480 543 529 538 258 254 256 503 499 501

Month 3,780 341 2,050 774 652 728 e2,620 e279 e1,750 1,830 459 1,310 676 371 533 338 171 283 509 483 498

94 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

June

1 2,190 2,070 2,120 697 679 689 — — e2,120 1,550 1,510 1,520 549 542 545 316 258 263 503 500 5022 2,270 2,180 2,210 691 668 681 — — e2,210 1,600 1,540 1,560 553 545 547 269 261 265 507 502 5043 2,340 2,270 2,310 695 675 687 — — e2,310 1,650 1,590 1,610 553 546 549 273 267 270 514 505 5094 2,430 2,300 2,390 707 687 696 — — e2,390 1,710 1,640 1,660 561 552 556 280 272 276 516 509 5125 2,550 2,430 2,490 708 691 701 — — e2,490 1,770 1,700 1,720 566 555 560 285 276 280 528 510 5146 2,700 2,520 2,580 704 690 698 — — e2,580 1,790 1,750 1,770 577 562 572 285 280 282 528 515 5217 2,660 2,390 2,550 693 679 686 — — e2,550 1,850 1,770 1,800 588 573 581 290 282 286 541 528 5338 2,810 503 2,520 697 685 691 — — e2,520 1,900 627 1,740 624 371 571 309 165 284 566 528 5399 1,930 536 1,330 690 679 685 — — e2,020 1,550 732 1,250 500 455 489 272 188 256 547 533 538

10 2,290 1,920 2,120 688 674 683 — — e1,770 1,650 1,550 1,590 504 487 494 277 268 272 555 540 54711 2,510 2,290 2,410 690 677 684 — — e2,040 1,730 1,650 1,670 540 504 522 286 276 281 572 544 55112 2,680 2,500 2,600 686 677 682 — — e2,100 1,780 1,730 1,740 552 529 542 287 281 284 596 546 56613 2,790 2,640 2,710 686 676 680 — — e2,230 1,820 1,760 1,790 560 537 552 309 285 291 588 552 56414 2,810 1,710 2,610 685 669 677 — — e2,180 1,840 1,260 1,700 654 539 564 291 283 288 581 556 56515 3,000 1,320 1,980 683 672 678 1,250 942 1,120 1,780 1,070 1,540 688 556 584 284 267 280 563 541 55016 2,400 1,500 2,200 675 667 671 1,680 1,250 1,450 1,800 929 1,680 603 471 583 295 225 278 541 533 53917 2,040 1,150 1,620 765 665 730 1,720 959 1,200 1,880 957 1,310 563 549 556 278 256 272 545 534 53718 2,570 2,040 2,330 767 758 762 1,750 1,100 1,420 1,590 1,520 1,550 563 546 559 281 277 279 540 536 53719 2,770 2,570 2,670 763 756 760 2,050 1,750 1,890 1,620 1,580 1,600 571 528 557 282 280 281 540 537 53820 2,950 2,770 2,840 764 754 759 2,210 2,050 2,150 1,670 1,610 1,630 579 536 564 291 281 285 545 537 54021 3,080 2,930 2,990 761 754 757 2,410 2,200 2,330 1,670 1,630 1,650 597 579 587 308 285 291 558 543 55022 3,090 2,890 2,990 762 756 759 2,440 2,360 2,410 1,740 1,280 1,580 624 593 601 295 292 294 556 549 55223 3,160 2,990 3,090 762 756 759 2,420 2,360 2,390 1,660 1,640 1,650 614 600 605 300 291 296 563 547 55424 3,340 3,050 3,180 760 751 757 2,520 2,330 2,420 1,660 1,650 1,660 632 611 e606 314 298 303 572 554 56025 3,580 3,130 3,340 762 756 758 2,550 2,400 2,460 1,660 1,640 1,650 — — e629 — — e295 583 558 56826 3,670 3,350 3,530 763 757 760 2,600 2,410 2,500 1,650 1,640 1,640 — — e609 — — e295 592 568 57727 3,710 3,390 3,580 764 757 760 2,580 2,420 2,490 1,640 1,630 1,640 — — e608 — — e295 611 577 58528 3,730 3,310 3,580 762 755 759 2,500 2,420 2,460 1,850 1,470 1,610 — — e617 — — e294 607 583 59729 3,600 3,400 3,490 763 751 756 2,470 2,350 2,410 1,700 1,560 1,620 — — e669 — — e294 606 598 60130 3,510 3,320 3,430 759 747 753 2,410 2,300 2,350 1,620 1,560 1,610 — — e678 — — e294 600 586 595

Month 3,730 503 2,660 767 665 719 e2,600 e942 e2,170 1,900 627 1,620 e688 e371 e575 e316 e165 e283 611 500 548

Table 14 95
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

July

1 3,500 3,310 3,430 757 744 752 2,340 2,230 2,300 1,630 1,590 1,610

—

— e719

—

— e294 596 587 591

2 3,460 3,330 3,390 755 746 751 2,420 2,290 2,350 1,620 1,610 1,610

—

— e684

—

— e294 610 592 599

3 3,490 3,340 3,410 754 746 750 2,520 2,280 2,400 1,610 1,610 1,610

—

— e682

—

— e294 610 590 597

4 3,460 3,360 3,420 754 737 746 2,600 2,320 2,480 1,610 1,600 1,610

—

— e678

—

— e294 603 592 598

5 3,530 3,440 3,490 750 733 742 2,840 2,380 2,640 1,610 1,600 1,610

—

— e696

—

— e294 617 597 607

6 3,550 659 1,800 744 732 738 2,710 675 1,890 1,600 43 730

—

— e536

—

— e220 616 591 604

7 2,660 1,280 2,080 752 724 736 5,130 115 894 1,910 872 1,320

—

— e457

—

— e292 592 580 586

8 2,960 210 2,090 739 722 732 1,550 120 1,090 1,620 30 1,050

—

— e464 232 112 210 586 566 578

9 1,700 359 1,040 748 730 739 1,030 139 481 1,180 82 714

—

— e388 215 178 205 581 566 573

10 2,120 1,030 1,740 752 740 746 1,070 556 770 1,490 815 1,260

—

— e402 239 214 227 588 572 579

11 2,650 2,120 2,400 762 742 751 1,470 1,060 1,300 1,590 1,490 1,520

—

— e421 257 238 249 592 581 586

12 2,960 2,550 2,750 764 747 759 1,720 1,450 1,590 1,610 1,590 1,590

—

— e629 267 255 260 596 583 588

13 3,170 2,760 2,980 763 756 760 1,850 1,700 1,770 1,610 1,600 1,610

—

— e612 306 265 270 606 592 598

14 3,350 3,050 3,180 762 756 759 1,910 1,820 1,870 1,610 1,610 1,610

—

— e619 299 270 277 616 598 607

15 3,400 3,240 3,330 763 757 760 1,980 1,860 1,920 1,610 1,600 1,610

—

— e641 289 275 282 620 600 611

16 3,520 3,340 3,470 761 756 759 2,030 1,910 1,980 1,610 1,600 1,600

—

— e644 291 282 287 641 618 624

17 3,610 3,400 3,560 762 756 758 2,030 1,920 1,980 1,600 1,590 1,600

—

— e653 300 291 295 637 622 629

18 3,660 3,530 3,620 762 755 759 2,030 1,820 2,000 1,600 1,590 1,600

—

— e662 344 300 305 640 623 631

19 3,680 3,560 3,630 763 755 759 2,170 1,960 2,040 1,590 1,520 1,580

—

— e661 319 304 307 666 625 644

20 3,660 3,530 3,610 765 757 761 2,160 1,940 2,050 1,590 1,570 1,580

—

— e673 350 308 320 674 636 655

21 3,670 3,520 3,600 767 760 763 2,180 1,840 2,070 1,580 1,570 1,580

—

— e685 321 315 318 674 642 655

22 3,740 3,550 3,630 770 762 766 2,240 158 2,030 1,580 160 1,470

—

— e701 344 316 322 678 646 661

23 3,880 3,550 3,710 769 762 766 886 567 698 1,530 391 1,360

—

— e642 324 318 321 673 647 657

24 3,560 3,230 3,480 772 764 768 1,390 850 1,090 1,580 1,500 1,550

—

— e683 325 318 322 650 636 642

25 3,610 3,340 3,510 772 764 768 1,620 1,390 1,500 1,600 1,510 1,590

—

— e696 350 322 329 643 635 638

26 3,770 3,430 3,620 771 764 767 1,910 1,610 1,750 1,590 1,550 1,590

—

— e707 335 324 328 657 637 646

27 4,270 3,400 3,530 793 759 779 2,030 1,800 1,900 1,590 1,480 1,570

—

— e748 352 326 332 669 646 655

28 4,590 3,560 3,910 788 781 785 2,020 1,750 1,920 1,620 1,560 1,570

—

— e727 375 327 337 663 648 653

29 3,570 2,980 3,430 789 782 786 2,020 1,680 1,940 1,570 1,560 1,570

—

— e727 361 327 333 654 643 650

30 3,520 3,120 3,410 788 781 784 2,070 1,710 1,970 1,560 1,540 1,550

—

— e712 331 329 330 652 645 648

31 3,480 3,320 3,410 787 781 784 2,040 1,780 2,010 1,550 1,540 1,550

—

— e722 329 328 329 651 643 647

Month 4,590 210 3,150 793 722 759 5,130 115 1,760 1,910 30 1,480

—

— e635 375 112 293 678 566 621

96 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

August

1 4,540 3,270 3,860 787 780 783 2,210 1,410 2,040 1,720 868 1,430 — — e708 331 326 329 651 640 6442 4,110 651 1,680 786 773 781 2,030 52 580 1,530 28 1,070 — — e609 357 72 280 662 618 6423 2,540 2,210 2,400 785 778 781 2,280 1,050 1,350 1,560 1,520 1,550 — — e658 365 315 331 658 648 6534 2,750 2,540 2,670 785 778 782 1,520 1,220 1,340 1,570 1,540 1,550 — — e685 335 319 327 687 654 6615 2,900 2,740 2,840 788 778 783 1,570 1,370 1,460 1,560 1,540 1,550 — — e706 327 209 310 694 677 6826 2,920 2,710 2,860 791 782 786 1,740 1,520 1,620 1,560 1,540 1,550 — — e720 323 314 320 682 672 6767 2,920 2,630 2,840 788 781 785 1,850 1,680 1,760 1,550 1,530 1,540 — — e706 327 321 324 695 677 6858 2,900 2,720 2,860 790 782 787 1,950 1,790 1,860 1,550 1,520 1,540 — — e730 339 323 332 704 682 6899 2,930 2,850 2,880 790 782 787 1,940 1,830 1,890 1,560 1,510 1,530 — — e730 379 335 341 701 685 693

10 2,940 2,790 2,860 790 782 786 2,060 1,850 1,950 1,530 1,510 1,520 — — e728 357 334 345 702 686 69211 3,010 2,630 2,840 790 780 785 2,010 1,840 1,930 1,530 1,510 1,520 — — e727 357 331 347 713 691 69812 3,310 2,780 3,030 788 774 782 2,070 1,860 1,950 1,520 1,500 1,510 — — e723 349 328 333 718 696 70413 2,940 2,820 2,910 781 769 775 2,190 1,910 2,030 1,520 1,490 1,510 — — e716 333 328 331 730 711 71814 3,180 633 2,460 777 762 772 2,400 135 1,480 1,500 40 1,080 — — e669 330 61 279 727 715 72015 1,820 980 1,400 776 766 771 698 264 525 1,390 58 801 — — e558 291 150 255 715 692 70516 2,300 1,820 2,080 790 771 783 1,090 698 869 1,520 1,390 1,480 — — e635 312 291 304 700 686 69317 2,520 2,300 2,440 791 782 786 1,410 1,070 1,180 1,530 1,510 1,520 — — e666 343 310 318 714 697 70618 2,670 2,390 2,570 791 783 787 1,570 1,410 1,470 1,550 1,520 1,530 — — e686 336 316 320 713 695 70319 2,750 2,470 2,630 790 782 786 1,760 1,570 1,680 1,540 1,520 1,530 — — e707 322 315 319 712 698 70320 2,770 2,590 2,700 788 779 784 1,890 1,750 1,820 1,530 1,520 1,520 — — e703 323 319 321 713 707 71021 3,290 2,690 2,910 788 781 784 1,960 1,810 1,880 1,530 700 1,360 — — e705 320 258 312 718 705 70922 2,690 2,450 2,560 786 778 783 2,040 1,860 1,950 1,520 1,480 1,500 — — e714 324 314 320 719 708 71323 2,760 2,450 2,590 786 780 783 1,970 1,840 1,910 — — e1,430 — — e711 323 318 320 714 704 71024 2,720 2,500 2,620 786 775 779 1,980 1,880 1,930 — — e1,440 — — e719 323 318 321 712 704 70725 2,790 2,440 2,650 781 773 777 2,060 1,940 2,000 — — e1,460 — — e717 325 320 322 711 699 70426 2,820 2,370 2,630 781 775 777 2,160 2,020 2,080 — — e1,450 — — e703 324 320 321 715 701 70727 2,780 2,430 2,630 780 772 776 2,220 2,060 2,130 — — e1,450 — — e728 327 319 322 717 705 71028 2,820 2,480 2,660 778 771 775 2,250 2,130 2,190 — — e1,470 — — e726 324 319 323 718 706 71129 2,820 2,640 2,720 778 767 772 2,290 2,190 2,220 — — e1,500 — — e575 327 275 318 724 717 72030 3,000 1,520 2,300 776 768 772 2,200 2,140 2,170 — — e1,280 — — e528 317 147 294 724 718 72131 2,490 1,590 2,160 779 770 774 2,160 2,070 2,130 — — e1,210 — — e556 322 309 316 720 717 718

Month 4,540 633 2,620 791 762 781 2,400 52 1,720 e1,720 e28 e1,430 — — e682 379 61 318 730 618 697

Table 14 97
Table 14.  Daily, monthly, and annual statistics for specific conductance for U.S. Geological Survey stations in the drinking-water source area for Cambridge, Massachusetts,

for water year 2005.—Continued[Units are in microsiemens per centimeter. e, estimated; —, no data; Max, maximum; Min, minimum]

Month 

and date

Cambridge Reservoir, 

unnamed tributary 2, near 

Lexington (01104415)

Cambridge Reservoir near Kendal 

Green (01104430)

Hobbs Brook, unnamed 

tributary 1, near Kendal 

Green (01104433)

Stony Brook, unnamed tributary 1, near 

Waltham (01104455)

Stony Brook at 

Route 20 at Waltham 

(01104460)

Stony Brook Reservoir, unnamed 

tributary 1, near 

Weston (01104475)

Fresh Pond gate 

house at Cambridge 

(422302071083801)

Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean

September

1 2,650 1,830 2,030 780 771 776 2,080 1,770 1,880

—

— e1,140

—

— e734 322 288 314 729 714 721

2 2,750 2,090 2,410 783 774 779 1,790 1,670 1,730

—

— e1,340

—

— e728 323 316 320 733 713 722

3 2,760 2,430 2,640 783 775 780 1,730 1,650 1,690

—

— e1,450

—

— e728 325 318 321 731 715 723

4 2,790 2,440 2,630 786 778 783 1,770 1,630 1,690

—

— e1,450

—

— e731 322 316 319 726 714 719

5 2,820 2,540 2,680 788 781 785 1,990 1,740 1,870

—

— e1,470

—

— e717 320 315 318 723 713 718

6 2,830 2,240 2,620 791 782 786 2,100 1,960 2,030

—

— e1,450

—

— e733 319 316 318 724 714 719

7 2,790 2,440 2,610 789 783 787 2,170 2,030 2,090

—

— e1,440

—

— e729 321 315 318 736 713 722

8 2,790 2,390 2,600 794 785 789 2,240 2,080 2,160

—

— e1,430

—

— e730 320 317 319 748 718 729

9 2,770 2,600 2,680 795 787 791 2,240 2,140 2,190

—

— e1,480

—

— e735 320 317 319 735 724 728

10 2,860 2,400 2,670 798 789 793 2,330 2,220 2,270

—

— e1,470

—

— e735 318 316 317 734 719 725

11 2,830 2,340 2,630 798 792 795 2,400 2,260 2,330

—

— e1,450

—

— e733 318 311 316 732 717 724

12 2,710 2,310 2,490 799 792 795 2,580 2,370 2,460

—

— e1,380

—

— e730 322 316 318 731 718 724

13 2,740 2,400 2,560 802 794 798 2,600 2,480 2,540

—

— e1,410

—

— e733 322 318 319 740 722 727

14 2,720 2,510 2,600 803 795 799 2,630 2,500 2,560

—

— e1,430

—

— e738 325 318 320 748 734 739

15 2,660 698 1,820 804 796 800 2,590 1,600 2,350

—

— e1,040

—

— e690 325 127 256 752 739 746

16 2,100 1,000 1,520 804 794 799 1,600 702 1,070

—

— e877

—

— e710 303 263 294 745 736 739

17 2,470 1,230 2,070 806 797 801 953 702 854

—

— e1,170

—

— e713 307 272 299 738 734 736

18 2,310 1,290 1,880 805 797 801 1,020 952 984

—

— e1,070

—

— e731 312 307 310 751 736 741

19 2,760 2,310 2,550 809 797 801 1,290 1,020 1,150

—

— e1,410

—

— e717 316 309 312 760 734 743

20 2,860 2,520 2,720 805 798 801 1,510 1,290 1,440

—

— e1,490

—

— e716 314 288 309 747 738 742

21 2,890 2,520 2,770 807 799 803 1,790 1,500 1,670

—

— e1,520

—

— e716 311 288 303 750 736 743

22 2,910 2,450 2,770 809 801 805 1,980 1,790 1,900

—

— e1,520

—

— e717 314 309 311 751 740 745

23 2,830 2,700 2,780 811 804 807 2,160 1,980 2,080

—

— e1,520

—

— e719 315 310 312 750 742 746

24 2,900 2,580 2,800 811 797 804 2,150 2,010 2,090

—

— e1,530

—

— e716 311 308 310 745 738 742

25 2,880 2,570 2,760 808 799 803 2,250 2,100 2,160

—

— e1,510

—

— e714 310 308 309 745 737 741

26 2,810 2,610 2,690 810 799 805 2,390 2,250 2,320

—

— e1,480

—

— e667 312 281 310 739 736 738

27 2,860 2,460 2,590 813 800 807 2,410 2,270 2,380

—

— e1,430

—

— e732 368 269 304 745 734 739

28 2,890 2,440 2,720 812 797 807 2,270 2,110 2,170

—

— e1,490

—

— e717 313 307 308 742 731 736

29 2,870 904 2,220 806 795 802 2,180 587 1,860

—

— e1,240

—

— e680 315 139 272 737 729 733

30 2,060 969 1,390 810 796 804 661 561 602

—

— e810

—

— e685 304 256 293 739 723 730

Month 2,910 698 2,460 813 771 796 2,630 561 1,890

—

— 1,360

—

— 719 368 127 309 760 713 733

Year 16,800 210 2,310 926 585 737 e10,300 e52 e2,220 e22,300 e28 e1,600 e1,770 e218 e538 e778 e61 e284 760 464 553Remarks Good Good Fair1 Good1 Good1 Excellent1 Good1

1Records that are estimated are rated as poor.

98 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Sample 

type Begin date Begin time End date End time

Discharge, 

instantaneous 

(million gallons per day)

P50051

Turbidity, 

water, unfiltered (NTRU)

P63676

Dissolved 

oxygen, water, unfiltered 

(milligrams 

per liter)

P00300

01104415 Base flow 20041215 1025 — — 0.47 1.7 11.4

01104415 Stormflow 20050708 1037 20050709 759 — 40 —

01104415 Base flow 20050726 1210 — — .01 1.1 5.3

01104415 Stormflow 20050814 1751 20050815 1157 — 79 —

01104433 Base flow 20041215 1205 — — .13 1.8 8.9

01104433 Stormflow 20050708 1126 20050709 900 — 20 —

01104433 Base flow 20050726 1245 — — 3.2 4.2

01104433 Stormflow 20050915 1008 20050916 215 — 45 —

01104455 Base flow 20041215 1355 — — .63 .6 9.7

01104455 Stormflow 20050708 1005 20050709 816 — 20 —

01104455 Base flow 20050726 1500 — — .19 .6 6.9

01104455 Stormflow 20050814 1555 20050814 1848 — 70 —

01104475 Base flow 20041215 1455 — — 1.2 1.3 12.3

01104475 Stormflow 20050708 1027 20050709 851 — 10 —

01104475 Base flow 20050726 1530 — — .13 .6 7.4

01104475 Stormflow 20050915 1012 20050915 1607 — 150 —

422302071083802 Untreated intake water20050720 1300 — — — 1.5 —

422302071083803 Finished production water20050720 1330 — — — .2 —

Blanks

01104455 Field blank 20050726 1501 — — — — —

USGS-MA-LAB Source water 20040601 1200 — — — — —

Table 15 99
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

pH, water, 

unfiltered, 

field

(standard 

units)

P00400

pH, water, 

unfiltered, 

laboratory 

(standard 

units)

P00403

Specific 

conductance, 

water, 

unfiltered, 

laboratory 

(microsiemens 

per centimeter 

at 25°C)

P90095

Specific 

conductance, 

water, 

unfiltered 

(microsiemens per 

centimeter 

at 25°C)

P00095

Temperature, water 

(°C)

P00010

Calcium, water, filtered 

(milligrams 

per liter)

P00915

Magnesium, 

water, 

filtered (milligrams 

per liter)

P00925

Potassium, 

water, filtered 

(milligrams 

per liter)

P00935

01104415 6.1 7.2 1,530 1500 3.0 47.2 6.74 4.16

01104415 6.8 6.7 e439 450 — 10.8 1.42 1.72

01104415 6.5 7.3 3160 3310 18.5 88.0 12.0 7.11

01104415 6.3 6.9 601 614 — 16.9 1.87 3.44

01104433 6.5 7.2 1,980 1,960 4.1 85.0 14.0 7.32

01104433 6.5 — — 511 — — — —

01104433 6.8 7.0 1,870 1,920 22.6 78.4 13.5 7.16

01104433 7.0 7.0 686 827 — 30.2 4.69 4.04

01104455 6.6 7.2 852 843 8.4 34.4 6.28 2.43

01104455 6.7 6.7 e218 241 — 8.20 1.47 0.88

01104455 6.3 7.1 1,610 1660 12.7 70.4 13.5 3.35

01104455 6.1 6.9 155 170 — 6.69 1.03 2.23

01104475 7.1 7.2 233 229 4.0 17.1 3.48 2.27

01104475 6.6 7.2 — 221 — 12.9 2.39 2.44

01104475 7.3 7.7 332 326 18.6 21.3 3.32 1.94

01104475 7.0 7.3 144 150 — 7.69 1.35 3.63

422302071083802 6.8 7.3 526 540 — 24.0 4.39 2.26

422302071083803 8.6 9.2 596 612 — 23.9 4.46 19.4

Blanks

01104455 — 7.9 <3 3 — <.02 <.008 <.16

USGS-MA-LAB 5.8 6.0 <3 0 — <.01 <.008 <.16

100 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Sodium, 

water, 

filtered 

(milligrams 

per liter)

P00930

Alkalinity, 

water, filtered, 

fixed endpoint 

(pH 4.5) titration, laboratory (milligrams 

per liter as 

calcium 

carbonate)

P29801

Chloride, 

water, 

filtered 

(milligrams 

per liter)

P00940

Sulfate, 

water, 

filtered 

(milligrams 

per liter)

P00945

Total nitrogen (nitrate 

+ nitrite + 

ammonia 

+ organicN), water, 

unfiltered, 

analytically 

determined 

(milligrams 

per liter)

P62855

Phosphorus, 

water, unfiltered 

(milligrams 

per liter)

P00665

Escherichia 

coli, m-TEC 

MF 

method, 

water 

(colonies per 

100 milliliters)

P31663

Cadmium, 

water, 

unfiltered 

(micrograms 

per liter)

P01027

01104415 254 47 449 25.9 2.02 e0.02 30 0.14

01104415 59.6 13 110 6.2 1.5 .31 id .06

01104415 538 47 970 28.5 1.57 <.02 190 .35

01104415 92.7 13 160 13.4 2.38 .5 18,000 .89

01104433 281 64 553 31.8 2.08 e.02 21 .29

01104433 — — — — 1.22 .12 id .16

01104433 254 58 542 27.6 1.58 .03 89 .09

01104433 88.9 28 176 18.2 2.21 .18 id .31

01104455 121 44 216 24.8 1.76 e.01 53 .10

01104455 27.2 11 51.7 5.8 0.93 .10 id .17

01104455 212 47 469 26.8 2.37 <.02 1,400 .18

01104455 20.3 9 33.7 9.2 2.96 .45 9,000 .69

01104475 24.3 31 37.7 20.0 1.96 e.01 4 <.04

01104475 18.2 24 31.3 11.4 1.28 .08 id .05

01104475 33.9 30 66.8 18.0 1.97 e.02 310 <.04

01104475 14.9 15 22.8 8.0 5.13 .80 43,000 .44

422302071083802 66.4 32 134 12.9 .74 <.02 — <.04

422302071083803 69.7 38 138 25.9 .94 <.02 — <.04

Blanks

01104455 <.20 <5 <.20 <.2 e.04 <.02 <1 <.04

USGS-MA-LAB <.10 <2 <.20 <.2 <.03 <.01 — <.04

Table 15 101
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Chromium, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P01034

Copper, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P01042

Iron, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P01045

Lead, 

water, 

unfiltered, 

recoverable (micrograms 

per liter)

P01051

Manganese, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P01055

Nickel, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P01067

Zinc, water, 

unfiltered,

 recoverable 

(micrograms 

per liter)

P01092

2,4,5-T, surrogate, Schedule 9060/2060, 

water, filtered 

(percent 

recovery)

P99958

01104415 2.9 3.4 300 0.45 216 2.05 18 99.4

01104415 1.3 2.9 170 1.12 96 .85 12 84

01104415 <.8 1.6 130 .33 332 .97 23 e87.7

01104415 12.5 28.0 11,500 86.2 1,260 9.99 151 e168

01104433 <.8 6.2 430 .50 283 4.05 58 95.6

01104433 3.3 8.0 1,340 9.14 146 2.08 50 e153

01104433 <.8 4.2 530 .70 406 4.24 34 e87.1

01104433 7.5 18.4 2,740 15.0 176 4.65 120 —

01104455 <.8 3.0 100 .27 153 2.45 19 89.1

01104455 13.6 32.5 1,640 17.5 148 3.21 70 e118

01104455 <.8 2.2 170 .64 487 4.51 16 e93.0

01104455 28.8 82.8 6,060 95.3 343 9.82 284 e172

01104475 <.8 1.9 160 .44 21 .87 4 94.5

01104475 .9 3.0 940 4.19 93 1.46 8 108

01104475 <.8 .8 80 .29 11 .91 e1 e79.9

01104475 6.7 22.8 7,350 42.6 1,120 7.87 71 e175

422302071083802 <.8 2.8 90 .28 44 .68 3 e123

422302071083803 <.8 <.6 e6 <.06 2 .58 <2 e127

Blanks

01104455 <.8 <.6 e3 <.06 1 e.09 e2 e80.1

USGS-MA-LAB <.8 <.6 <9.0 <.06 <.2 <.16 <2 67.7

102 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

2,4-D methyl 

ester, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50470

2,4-D, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P39732

2,4-DB, water, 

filtered 

(0.7-micron 

glassfiber filter), 

recoverable 

(micrograms 

per liter)

P38746

2-Chloro-4-

isopropylamino-6-aminos-triazine, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P04040

2-Chloro-6-

ethyl­amino-4-

aminos-triazine, water, filtered, 

recoverable 

(micrograms 

per liter)

P04038

2-Hydroxy-4-

isopropylamino-6-ethylamino-s-triazine, 

water, filtered, 

recoverable 

(micrograms 

per liter)

P50355

3-Hydroxy 

carbofuran, water, 

filtered 

(0.7-micron 

glass- fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49308

Ketocarbofuran, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50295

01104415 <0.016 e0.02 <0.02 <0.03 <0.08 <0.032 <0.008 <0.02

01104415 <.016 <.04 <.02 <.03 <.08 <.032 <.008 —

01104415 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104415 <.214 e7.92 <.02 <.03 <.08 <.032 <.008 <.02

01104433 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104433 <.016 <.04 <.02 <.03 <.08 <.032 <.008 —

01104433 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104433 <.016 e.22 <.02 <.03 <.08 <.032 <.008 <.02

01104455 <.016 <.04 <.02 <.03 e.01 <.032 <.008 <.02

01104455 <.016 <.04 <.02 <.03 <.08 <.032 <.008 —

01104455 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104455 <.016 e.04 <.02 <.03 <.08 <.032 <.008 e.08

01104475 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104475 <.016 <.04 <.02 <.03 <.08 <.032 <.008 —

01104475 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

01104475 <.139 e3.41 <.02 <.03 <.08 <.032 <.008 <.02

422302071083802 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.25

422302071083803 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.25

Blanks

01104455 <.016 <.04 <.02 <.03 <.08 <.032 <.008 <.02

USGS-MA-LAB <.009 <.02 <.02 <.03 <.04 <.008 <.006 <1.50

Table 15 103
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

9H-Fluorene, 

water, unfiltered, recoverable (micrograms per liter)

P34381

Acenaphthene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34205

Acenaphthylene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34200

Acifluorfen, 

water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49315

Aldicarb 

sulfone, 

water, 

filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms per 

liter)

P49313

Aldicarb sulfoxide, water, 

filtered (0.7-micron 

glass-fiber filter), 

recoverable 

(micrograms per 

liter)

P49314

Aldicarb, 

water, 

filtered 

(0.7-micron 

glassfiber filter), 

recoverable 

(micrograms 

per liter)

P49312

Anthracene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34220

01104415 e0.005 <2.0 <2.0 <0.028 <0.02 <0.022 <0.04 e0.007

01104415 e.03 e.02 <2 <.028 <.02 <.022 <.04 e.05

01104415 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104415 <2 <2 e.2 <.028 <.02 <.022 <.04 e.2

01104433 <2 e.004 <2 <.028 <.02 <.022 <.04 e.01

01104433 e.02 <2 <2 <.028 <.02 <.022 <.04 <2

01104433 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104433 e.02 e.02 e.02 <.028 <.02 <.022 <.04 e.05

01104455 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104455 e.2 e.1 e.03 <.028 <.02 <.022 <.04 e.4

01104455 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104455 e.3 e.2 <2 <.028 <.02 <.022 <.04 e.6

01104475 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104475 e.03 e.02 <2 <.028 <.02 <.022 <.04 e.05

01104475 <2 <2 <2 <.028 <.02 <.022 <.04 <2

01104475 e.1 e.07 e.09 <.028 <.02 <.022 <.04 e.3

422302071083802 <2 <2 <2 <.028 <.02 <.022 <.04 <2

422302071083803 <2 <2 <2 <.028 <.02 <.022 <.04 <2

Blanks

01104455 <2 <2 <2 <.028 <.02 <.022 <.04 <2

USGS-MA-LAB <2 <2 <2 <.007 <.02 <.008 <.04 <2

104 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Atrazine, 

water, 

filtered, 

recoverable 

(micrograms 

per liter)

P39632

Barban, 

surrogate, 

Schedules 

2060/9060, 

water, 

filtered 

(percent 

recovery)

P90640

Bendiocarb, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50299

Benomyl, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P50300

Bensulfuron, water, 

filtered, 

recoverable 

(micrograms

per liter)

P61693

 Bentazon, 

water, filtered 

(0.7-micron 

glassfiber filter), 

recoverable 

(micrograms 

per liter)

P38711

Benzo[a]

anthracene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34526

Benzo[a]

pyrene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34247

01104415 <0.008 e92.0 <0.02 <0.022 <0.02 <0.01 <2.0 <1.0

01104415 <.008 e33.9 <.02 <.022 <.02 <.01 e.4 e.6

01104415 <.008 e44.4 <.02 <.022 <.02 <.01 <2 <1

01104415 <.008 e42.6 <.02 <.022 <.02 <.01 e.8 e1

01104433 <.008 e76 <.02 <.022 <.02 <.01 <2 <1

01104433 <.008 e18 <.02 <.022 <.02 <.01 e.1 e.2

01104433 <.008 e15.6 <.02 <.022 <.02 <.01 <2 <1

01104433 <.008 66.2 <.02 <.022 <.02 <.01 e.3 e.4

01104455 <.008 e83.8 <.02 <.022 <.02 <.01 <2 <1

01104455 <.008 e16.6 <.02 <.022 <.02 <.01 e2 e2

01104455 <.008 90.7 <.02 <.022 <.02 <.01 <2 <1

01104455 <.008 e389 <.02 <.022 <.02 <.01 e2 3

01104475 <.008 e108 <.02 .03 <.02 <.01 <2 <1

01104475 <.008 e23.5 <.02 e.176 <.02 <.01 e.2 e.3

01104475 <.008 81.9 <.02 e.159 <.02 <.01 <2 <1

01104475 <.008 89.7 <.02 <.022 <.02 <.01 e1 2

422302071083802 <.008 e39 <.02 <.022 <.02 <.01 <2 <1

422302071083803 <.008 118 <.02 <.022 <.02 <.01 <2 <1

Blanks

01104455 <.008 92.2 <.02 <.022 <.02 <.01 <2 <1

USGS-MA-LAB <.009 84.9 <.03 <.004 <.02 <.01 <2 <1

Table 15 105
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Benzo[b] fluoranthene, water, 

unfiltered, 

recoverable 

(micrograms per 

liter)

P34230

 Benzo[ghi] 

perylene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34521

 Benzo[k]

fluoranthene, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34242

Bromacil, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P04029

Bromoxynil, 

water, 

filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms per 

liter)

P49311

Caffeine, 

water, filtered, 

recoverable 

(micrograms 

per liter)

P50305

Caffeine-13C, 

surrogate, 

schedule 

9060/2060, 

water, 

filtered 

(percent 

recovery)

P99959

Carbaryl, water, 

filtered 

(0.7-micron 

glass- fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49310

01104415 <2.0 <3.0 <2.0 <0.02 <0.03 0.02 112.0 <0.02

01104415 e1 e.6 e.3 <.02 <.03 .77 83.9 .03

01104415 <2 <3 <2 <.02 <.03 <.018 e118 <.02

01104415 e2 e.5 e.6 <.02 <.03 e.773 e124 e.03

01104433 <2 <3 <2 <.02 <.03 .48 91.6 <.02

01104433 e.4 e.2 e.1 <.02 <.03 .26 98.9 <.02

01104433 <2 <3 <2 <.02 <.03 e.678 e117 <.02

01104433 e.7 e.3 e.3 <.02 <.03 e1.69 97.5 e.01

01104455 <2 <3 <2 <.02 <.03 .18 104 <.02

01104455 e1 e2 e1 <.02 <.03 .23 97.7 <.02

01104455 <2 <3 <2 <.02 <.03 <.018 e117 <.02

01104455 5 e1 e2 <.02 <.03 e.583 e360 <.02

01104475 <2 <3 <2 <.02 <.03 e.009 102 <.02

01104475 e.4 e.3 e.1 <.02 <.03 .04 88.2 <.02

01104475 <2 <3 <2 <.02 <.03 <.018 e105 <.02

01104475 3 e2 e1 <.02 <.03 .23 100 e.01

422302071083802 <2 <3 <2 <.02 <.03 .02 98.6 <.02

422302071083803 <2 <3 <2 <.02 <.03 <.018 116 <.02

Blanks

01104455 <2 <3 <2 <.02 <.03 <.018 e154 <.02

USGS-MA-LAB <2 <3 <2 <.03 <.02 <.010 127 <.03

106 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Carbofuran, 

water, filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms per 

liter)

P49309

Chloramben 

methylester, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P61188

Chlorimuron, 

water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50306

Chlorodiamino-striazine, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P04039

Chlorothalonil, water, 

filtered 

(0.7-micron 

glass- fiber filter), 

recoverable 

(micrograms per 

liter)

P49306

Chrysene, water, unfiltered, 

recoverable 

(micrograms 

per liter)

P34320

Clopyralid, water, 

filtered 

(0.7-micron 

glass-fiber filter), 

recoverable 

(micrograms 

per liter)

P49305

Cycloate, water, filtered, 

recoverable 

(micrograms 

per liter)

P04031

01104415 <0.016 <0.02 <0.032 <0.04 <0.04 <3.0 <0.02 <0.01

01104415 <.016 <.02 <.032 <.04 <.04 e.7 <.02 <.01

01104415 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104415 <.016 <.02 <.032 <.04 <.04 e.9 <.02 <.01

01104433 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104433 <.016 <.02 <.032 <.04 <.04 e.3 <.02 <.01

01104433 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104433 <.016 <.02 <.032 <.04 <.04 e.5 <.02 <.01

01104455 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104455 <.016 <.02 <.032 <.04 <.04 e2 <.02 <.01

01104455 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104455 <.016 <.02 <.032 <.04 <.04 4 <.02 <.01

01104475 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104475 <.016 <.02 <.032 <.04 <5.54 e.3 <.02 <.01

01104475 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

01104475 <.016 <.02 <.032 <.04 <.04 e2 <.02 <.01

422302071083802 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

422302071083803 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

Blanks

01104455 <.016 <.02 <.032 <.04 <.04 <3 <.02 <.01

USGS-MA-LAB <.006 <.02 <.010 <.01 <.04 <3 <.01 <.01

Table 15 107
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Dacthal monoacid, water, 

filtered (0.7-micron glass- fiber 

filter), recoverable (micrograms per liter)

P49304

Dibenzo[a,h] 

anthracene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34556

Dicamba, 

water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P38442

Dichlorprop, water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable (micrograms 

per liter)

P49302

Dinoseb, 

water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms 

per liter)

P49301

Diphenamid, 

water, filtered, 

recoverable 

(micrograms 

per liter)

P04033

Diuron, water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49300

Fenuron, water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49297

01104415 <0.03 <3.0 <0.04 <0.03 <0.04 <0.01 <0.01 <0.02

01104415 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104415 <.03 <3 <.04 <.03 <.04 <.01 .02 <.02

01104415 <.03 <3 <.09 <.03 <.04 <.01 <.01 <.02

01104433 <.03 <3 <.04 <.03 <.04 <.01 .08 <.02

01104433 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104433 <.03 <3 <.04 <.03 <.04 <.01 e.03 <.02

01104433 <.03 e.09 <.04 <.03 <.04 <.01 e.14 <.02

01104455 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104455 <.03 e.5 <.04 <.03 <.04 <.01 <.01 <.02

01104455 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104455 <.03 e.4 <.04 <.03 <.04 <.01 <.01 <.02

01104475 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104475 <.03 e.08 <.04 <.03 <.04 <.01 <.01 <.02

01104475 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

01104475 <.03 e.4 <.04 <.03 <.04 <.01 <.01 <.02

422302071083802 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

422302071083803 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

Blanks

01104455 <.03 <3 <.04 <.03 <.04 <.01 <.01 <.02

USGS-MA-LAB <.01 <3 <.01 <.01 <.01 <.03 <.01 <.03

108 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Flumetsulam, 

water, 

filtered, 

recoverable 

(micrograms 

per liter)

P61694

Fluometuron, 

water, filtered 

(0.7-micron 

glass-fiber 

filter) recoverable (micrograms 

per liter)

P38811

Fluoranthene, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34376

Imazaquin, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P50356

Imazethapyr, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50407

Imidacloprid, 

water, filtered, 

recoverable 

(micrograms 

per liter)

P61695

Indeno[1,2,3-

cd] pyrene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34403

Linuron, 

water, filtered 

(0.7-micron 

glass-fiber filter), 

recoverable 

(micrograms 

per liter)

P38478

01104415 <0.04 <0.02 e0.01 <0.04 <0.04 e0.011 <3.0 <0.01

01104415 <.04 <.02 e1 <.04 <.04 .18 e.6 <.01

01104415 <.04 <.02 <2 <.04 <.04 <.020 <3 <.01

01104415 <.04 <.02 e2 <.04 <.04 e.375 e.5 <.01

01104433 <.04 <.02 e.05 <.04 <.04 <.020 <3 <.01

01104433 <.04 <.02 e.5 <.04 <.04 .23 e.2 <.01

01104433 <.04 <.02 e.1 e.01 <.04 e.067 <3 <.01

01104433 <.04 <.02 e.9 e.06 <.04 <.020 e.3 <.01

01104455 <.04 <.02 <2 <.04 <.04 <.020 <3 <.01

01104455 <.04 <.02 5 <.04 <.04 <.020 e1 <.01

01104455 <.04 <.02 e.04 e.01 <.04 <.020 <3 <.01

01104455 <.04 <.02 9 <.04 <.04 e.113 e1 <.01

01104475 <.04 <.02 e.02 <.04 <.04 .52 <3 <.01

01104475 <.04 <.02 e.7 <.04 <.04 e1.00 e.2 <.01

01104475 <.04 <.02 <2 <.04 <.04 .36 <3 <.01

01104475 <.04 <.02 4 <.19 <.04 .34 e1 <.01

422302071083802 <.04 <.02 e.01 <.04 <.04 .02 <3 <.01

422302071083803 <.04 <.02 <2 <.04 <.04 <.020 <3 <.01

Blanks

01104455 <.04 <.02 <2 <.04 <.04 <.020 <3 <.01

USGS-MA-LAB <.01 <.03 <2 <.02 <.02 <.007 <3 <.01

Table 15 109
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

MCPA, 

water, filtered 

(0.7-micron 

glass-fiber 

filter), recoverable (micrograms per liter)

P38482

MCPB, water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P38487

Metalaxyl, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50359

Methiocarb, water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable (micrograms 

per liter)

P38501

Methomyl, 

water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms per 

liter)

P49296

Metsulfuron, 

water, filtered, 

recoverable 

(micrograms 

per liter)

P61697

N-(4-Chlorophenyl)-

N’-methylurea, water, 

filtered, recoverable 

(micrograms 

per liter)

P61692

Neburon, 

water, filtered 

(0.7-micron 

glass-fiber filter), 

recoverable 

(micrograms 

per liter)

P49294

01104415 — <0.01 <0.01 <0.010 <0.020 <0.03 <0.04 <0.01

01104415 <0.03 <.01 <.01 <.010 <.020 <.30 <.04 <.01

01104415 <.03 <.01 <.01 <.010 — <.03 <.04 <.01

01104415 <.05 <.01 <.01 <.010 <.020 e1.40 <.04 <.01

01104433 — <.01 <.01 <.010 <.020 <.03 <.04 <.01

01104433 <.06 <.01 <.01 <.010 <.020 e1.26 <.04 <.01

01104433 <.03 <.01 <.01 <.010 — e3.90 <.04 <.01

01104433 <.03 <.01 <.01 <.010 <.020 <.03 <.04 <.01

01104455 — <.01 <.01 <.010 <.020 <.03 <.04 <.01

01104455 <.03 <.01 <.01 <.010 <.020 <.41 <.04 <.01

01104455 <.03 <.01 <.01 <.010 — <.03 <.04 <.01

01104455 <.09 <.01 <.01 <.010 <.020 e2.52 <.04 <.01

01104475 — <.01 .04 <.010 <.020 <.03 <.04 <.01

01104475 <.03 <.01 .02 <.010 <.020 <.03 <.04 <.01

01104475 <.03 <.01 e.01 <.010 — <.03 <.04 <.01

01104475 e.16 <.01 <.01 <.010 <.020 <.03 <.04 <.01

422302071083802 <.03 <.01 <.01 <.010 <.020 <.03 <.04 <.01

422302071083803 <.03 <.01 <.01 <.010 <.020 <.03 <.04 <.01

Blanks

01104455 <.03 <.01 <.01 <.010 — <.03 <.04 <.01

USGS-MA-LAB <.02 <.01 <.02 <.008 <.004 <.03 <.02 <.01

110 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Nicosulfuron, 

water, filtered, 

recoverable 

(micrograms per 

liter)

P50364

Nitrobenzene, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34447

Norflurazon, water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms 

per liter)

P49293

Oryzalin, 

water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable (micrograms 

per liter)

P49292

Oxamyl, 

water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms 

per liter)

P38866

Phenanthrene, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34461

Picloram, 

water, 

filtered (0.7-

micron 

glassfiber filter), 

recoverable 

(micrograms 

per liter)

P49291

Propham, 

water, filtered 

(0.7-micron 

glass- fiber filter), 

recoverable 

(micrograms 

per liter)

P49236

01104415 <0.04 <2 <0.02 <0.01 <0.03 <2.0 <0.03 <0.030

01104415 <.04 <2 <.02 <.01 <.03 e.6 <.03 <.030

01104415 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

01104415 <.04 <2 <.02 <.01 <.03 e.6 <.03 <.030

01104433 <.04 <2 <.02 <.01 <.03 e.02 <.03 <.030

01104433 <.04 <2 <.02 <.01 <.03 e.2 <.03 <.030

01104433 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

01104433 <.04 <2 <.02 <.01 <.03 e.3 <.03 <.030

01104455 <.04 <2 .15 <.01 <.03 <2 <.03 <.030

01104455 <.04 <2 .12 <.01 <.03 2 <.03 <.030

01104455 <.04 <2 .08 <.01 <.03 <2 <.03 <.030

01104455 <.04 <2 <.02 <.01 <.03 4 <.03 <.030

01104475 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

01104475 <.04 <2 <.02 <.01 <.03 e.3 <.03 <.030

01104475 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

01104475 <.04 <2 <.03 <.01 <.03 e2 <.03 <.030

422302071083802 <.04 <2 <.02 <.01 <.03 e.01 <.03 <.030

422302071083803 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

Blanks

01104455 <.04 <2 <.02 <.01 <.03 <2 <.03 <.030

USGS-MA-LAB <.01 <2 <.02 — <.01 <2 <.02 <.010

Table 15 111
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Propiconazole, water, 

filtered, 

recoverable 

(micrograms 

per liter)

P50471

Propoxur, 

water, 

filtered 

(0.7-micron 

glass-

 fiber filter), 

recoverable 

(micrograms 

per liter)

P38538

Pyrene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34469

Siduron, 

water, 

filtered, recoverable 

(micrograms per 

liter)

P38548

Sulfometuron, water, filtered, 

recoverable 

(micrograms 

per liter)

P50337

Tebuthiuron, 

water, filtered 

(0.7-micron 

glass-fiber 

filter), recoverable (micrograms per 

liter)

P82670

Terbacil, water, filtered, 

recoverable 

(micrograms 

per liter)

P04032

Triclopyr, water, filtered 

(0.7-micron 

glass-fiber 

filter), 

recoverable 

(micrograms 

per liter)

P49235

01104415 <0.01 <0.008 e0.009 <0.02 <0.038 <0.026 <0.016 <0.03

01104415 <.01 <.008 e1 e.01 <.038 <.026 <.016 <.03

01104415 <.01 <.008 <2 <.02 <.038 <.026 <.016 <.03

01104415 <.01 <.008 e2 e.06 <.038 <.026 <.016 e1.44

01104433 <.01 <.008 e.03 <.02 <.038 <.026 <.016 <.03

01104433 <.01 e.246 e.4 e.01 <.038 <.026 <.016 <.03

01104433 <.01 <.008 e.09 <.02 <.038 <.026 <.016 <.03

01104433 <.01 <.008 e.6 e.04 <.038 <.026 <.016 <.03

01104455 <.01 <.008 <2 <.02 <.038 <.026 <.016 <.03

01104455 <.01 <.008 3 e.01 <.038 <.026 <.016 <.03

01104455 <.01 <.008 <2 <.02 <.038 <.026 <.016 <.03

01104455 <.01 <.008 7 e.03 <.038 <.026 <.016 <.03

01104475 .18 <.008 e.01 <.02 <.038 <.026 <.016 <.03

01104475 .54 <.008 e.5 e.01 <.038 <.026 <.016 .25

01104475 .12 <.008 <2 <.02 <.038 <.026 <.016 <.03

01104475 <.01 <.008 3 <.02 <.038 <.026 <.016 <.03

422302071083802 <.01 <.008 e.005 e.004 <.038 <.026 <.016 <.03

422302071083803 <.01 <.008 <2 <.02 <.038 <.026 <.016 <.03

Blanks

01104455 <.01 <.008 <2 <.02 <.038 <.026 <.016 <.03

USGS-MA-LAB <.02 <.008 <2 <.02 <.009 <.006 <.010 <.02

112 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
Table 15.  Physical properties and concentrations of major inorganic constituents, nutrients, trace metals, suspended sediments,

Escherichia coli bacteria, polyaromatic hydrocarbons, and polar pesticides and metabolites for base-flow and stormflow water

samples collected in four subbasins and the Fresh Pond intake structure in the Cambridge, Massachusetts, drinking-water source area for

water year 2005.—Continued

[Escherichia coli concentrations were mathematically estimated from subcomposites. PXXXXX, National Water Quality Laboratory parameter code; °C, 

degree Celsius; e, estimated; NTRU, nephelometric turbidity ratio units; USGS-MA-LAB, U.S. Geological Survey-Massachusetts Water Science Center 

laboratory; <, concentration is less than value shown; id, insufficient data to estimate composite value; —, no data]

USGS station 

number

Naphthalene, water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P34696

2-Fluorobiphenyl, 

surrogate 

(percent 

recovery)

P49279

Terphenyld14, surrogate (percent 

recovery)

P49278

 Suspended 

sediment, 

sieve 

diameter 

(percent 

smaller 

than 0.063 

millimeters)

P70331

Suspended 

sediment, 

sieve 

diameter 

(percent 

smaller 

than 0.25 

millimeters)

P70333

Suspended 

sediment 

concentration 

(milligrams 

per liter)

P80154

Perylene, 

water, 

unfiltered, 

recoverable 

(micrograms 

per liter)

P77801

01104415 <2.0 97 98 64 91 3 —

01104415 e.03 93 60 46 73 144 e0.1

01104415 <2 87 69 56 78 2 <1

01104415 <2 100 55 11 19 1040 e.2

01104433 <2 95 77 67 87 2 —

01104433 e.03 95 60 82 93 29 e.05

01104433 <2 91 76 68 99 17 <1

01104433 <2 100 54 85 99 59 e.08

01104455 <2 95 97 50 79 2 —

01104455 e.04 91.2 54.6 67 93 54 e.4

01104455 <2 93 89 55 82 2 <1

01104455 <2 92 47 59 89 248 e.6

01104475 <2 50 61 61 87 4 —

01104475 e.01 99 72 50 80 29 e.06

01104475 <2 100 93 71 86 1 <1

01104475 e.04 83 42 70 95 348 e.4

422302071083802 <2 100 95 — — 1 —

422302071083803 <2 98 32 — — 1 —

Blanks

01104455 e.07 90 87 0 0 <1 <1

USGS-MA-LAB <2 95 59 0 0 <1 —

Table 15 113
Table 16.  Concentrations of Escherichia coli for water samples collected during base flow and storms in

four subbasins in the Cambridge, Massachusetts, drinking-water source area for water year 2005.

[B, water sample collected during base flow; S, composite water sample collected during stormflow; PB, processing equipment 

blank; FB, field blank; R, replicate sample; col/100 mL, colony per 100 milliliters; —, no data; <, less than; K, nonideal 

colony count]

USGS station

identifier

Sample 

type

Begin 

date

Begin 

time

End 

date

End 

time

Escherichia coli

(col/100 mL)

01104415 B 20041215 1025 — — 30

01104415 S 20050708 1038 20050708 1935 36,000

01104415 S 20050708 1941 20050708 2338 11,000

01104415 B 20050726 1210 — — 190

01104415 S 20050814 1751 20050815 1157 18,000

01104433 B 20041215 1205 — — 21

01104433 S 20050708 1127 20050708 2119 3,600

01104433 S 20050709 19 20050709 900 4,300

01104433 B 20050726 1245 — — 89

01104433 S 20050915 1008 20050915 1443 6,500

01104433 S 20050915 1457 20050915 1919 5,300

01104455 B 20041215 1355 — — 53

01104455 S 20050708 1006 20050708 2018 9,200

01104455 S 20050708 2030 20050709 816 3,700

01104455 B 20050726 1500 — — 1,400

01104455 S 20050814 1555 20050814 1848 9,000

01104475 B 20041215 1455 — — K4

01104475 S 20050708 1028 20050708 2031 5,700

01104475 S 20050708 2043 20050709 632 1,700

01104475 B 20050726 1530 — — 310

01104475 S 20050915 1012 20050915 1607 43,000

Blanks

01104415 PB 20050726 1211 — — <1

01104433 PB 20040827 915 — — <1

01104455 FB 20050726 1501 — — <1

01104455 PB 20050814 1749 — — <1

01104433 PB 20050915 1530 — — <1

Replicate samples

01104433 B 20041215 1205 — — 21

01104433 R 20041215 1205 — — K11

01104455 B 20041215 1355 — — 53

01104455 R 20041215 1355 — — 84

01104475 B 20041215 1455 — — K4

01104475 R 20041215 1455 — — K11

01104415 S 20050814 1751 20050815 1157 18,000

01104415 R 20050814 1752 — — 12,000

01104433 S 20050915 1008 20050915 1443 6,500

01104433 R 20050915 1009 — — 7,500

114 Hydrologic, Water-Quality, and Meteorological Data for the Cambridge, Mass., Drinking-Water Source Area, WY 2005
A

alkalinity  The capacity of solutes in an aqueous system to neutralize acid. Alkalinity is 

determined by titration of a filtered sample.

annual runoff  The total quantity of water that 

is discharged (runs off) from a drainage basin 

in a year. This report presents annual runoff 

data as volumes in millions of gallons per day 

per square mile and as depths of water on the 

drainage basin in inches.

B

base flow  Sustained flow of a stream in the 

absence of direct runoff. It includes natural and 

human-induced stream flows. Natural base flow 

is sustained largely by ground-water discharge.

C

capacity  The volume of water in a reservoir 

or lake. Unless otherwise indicated, volume is 

computed on the basis of a level pool and does 

not include bank storage.

control  A feature in the channel that physically affects the water-surface elevation and 

thereby determines the stage-discharge relation 

at the station. This feature may be a constriction of the channel, a bedrock outcrop, a gravel 

bar, an artificial structure, or a uniform cross 

section over a long reach of the channel.

D

datalogger  A microprocessor-based dataacquisition system designed specifically to 

acquire, process, and store data. Most dataloggers are capable of transmitting data by phone 

modem, cellular modem, radio, or satellitecommunication systems.

datum  A surface or point relative to which 

measurements of height and horizontal position 

are reported. A vertical datum is a horizontal 

surface used as the zero point for measurements 

of stream stage or altitude; a horizontal datum 

is a reference for positions given in terms of 

latitude-longitude, state plane coordinates, or 

Univeral Transverse Mercado coordinates.

discharge or flow  The rate at which matter 

passes through a cross section of a stream 

channel or other water body per unit of time. 

The term commonly refers to the volume of 

water (including, unless otherwise stated, any 

sediment or other constituents suspended or 

dissolved in the water) that passes a cross 

section in a stream channel, canal, or pipeline 

within a given period of time.

dissolved  The material in a representative 

water sample that passes through a 

0.45-micrometer membrane filter. This is a 

convenient operational definition used by 

Federal and State agencies that collect waterquality data. Determinations of dissolved 

constituent concentrations are made on sample 

water that has been filtered.

dissolved oxygen  Molecular oxygen 

(O2, oxygen gas) dissolved in water. The 

concentration in water is a function of 

atmospheric pressure, temperature, and 

dissolved-solids concentration of the water. 

The ability of water to retain oxygen decreases 

with increasing temperature or dissolved-solids 

concentration. Photosynthesis and respiration 

by plants commonly cause diurnal variations in 

dissolved-oxygen concentration in water from 

some streams.

drainage area  The area measured in a 

horizontal plane upstream from the location 

from which surface runoff from precipitation 

normally drains by gravity to the stream at that 

location. Drainage areas given herein include 

all closed basins, or noncontributing areas, 

within the area unless otherwise specified.

drainage basin  A part of the Earth’s surface 

that contains a drainage system with a common 

outlet for its surface runoff.

Glossary

Definitions in this glossary are adapted from the U.S. Geological Survey Annual Water Data 

Report for Massachusetts and Rhode Island (Socolow and others, 2004).
E

Escherichia coli (E. coli)  Bacteria present in 

the intestine and feces of warm-blooded animals. E. coli are a member species of the fecal 

coliform group of indicator bacteria. In the 

laboratory, they are defined as those bacteria 

that produce yellow or yellow-brown colonies 

on a filter pad saturated with urea substrate 

broth after primary culturing for 22 to 24 hours 

at 44.5°C on mTEC medium (nutrient medium 

for bacterial growth). Their concentrations are 

expressed as number of colonies per 100 mL of 

sample.

estimated (E) concentration value  Reported 

when an analyte is detected and all criteria for 

a positive result are met. If the concentration 

is less than the method detection limit (MDL), 

an “E” code will be reported with the value. 

Also, if the analyte is qualitatively identified 

as present, but the quantitative determination 

is substantially more uncertain, the USGS 

National Water Quality Laboratory will identify 

the result with an “E” code even though the 

measured value is greater than the MDL. A 

value reported with an “E” code should be used 

with caution. When no analyte is detected in a 

sample, the default reporting value is the MDL 

preceded by a less than sign (<).

G

gill radiation shield  A louvered structure 

which allows air to pass freely through the 

shield thereby serving to keep a temperature 

sensor at or near ambient temperature. The 

shield’s white color reflects solar radiation.

I

inch  In this report, this unit is used for the 

depth to which a drainage area would be covered with water if all of the runoff for a given 

time period were uniformly distributed over it. 

See also annual runoff

instantaneous discharge  The discharge at a 

particular instant of time. See also discharge

L

laboratory reporting level (LRL)  The 

concentration generally equal to twice 

the yearly determined long-term method 

detection level (LT-MDL). The LRL controls 

false negative error. The probability of 

falsely reporting a nondetection for a sample 

containing an analyte at a concentration equal 

to or greater than the LRL is predicted to be 

less than or equal to 1 percent. The value of 

the LRL will be reported with a “less than” (<) 

remark code for samples in which the analyte 

was not detected. The USGS National Water 

Quality Laboratory collects quality-control 

data from selected analytical methods on a 

continuing basis to determine LT-MDLs and to 

establish LRLs. These values are reevaluated 

annually on the basis of the most current 

quality-control data and, therefore, may change.

long-term method detection level (LT-MDL) 

A concentration derived by determining the 

standard deviation of a minimum of 24 methoddetection-limit spike-sample measurements 

over an extended period of time. LT-MDL data 

are collected on a continuous basis to assess 

year-to-year variations in the LT-MDL. The LTMDL controls false positive error. The chance 

of falsely reporting a concentration at or greater 

than the LT-MDL for a sample not containing 

the analyte is predicted to be less than or equal 

to 1 percent.

M

mean discharge  The arithmetic mean of individual daily mean discharges during a specific 

period. See also discharge

metabolite  Any substance produced, used, or 

remaining during or after metabolism (that is, 

digestion).

method detection limit  The minimum 

concentration of a substance that can be measured and reported with 99-percent confidence 

that the analyte concentration is greater than 

zero. It is determined from the analysis of a 

sample in a given matrix containing the analyte. 

At the MDL concentration, the risk of a false 

positive is predicted to be less than or equal to 

1 percent.

micrograms per liter  A unit expressing the 

concentration of chemical constituents in water 

as mass (micrograms) of constituent per unit 

volume (liter) of water. One thousand micrograms per liter is equivalent to 1 milligram per 

liter. One microgram per liter is equivalent to 

1 part per billion.

microsiemens per centimeter  A unit expressing the amount of electrical conductivity of a 

solution as measured between opposite faces 

of a centimeter cube of solution at a specified 

temperature. Siemens is the International 

System of Units nomenclature. It is synonymous with mhos and is the reciprocal of resistance in ohms.
milligrams per liter  A unit for expressing the 

concentration of chemical constituents in water 

as the mass (milligrams) of constituent per unit 

volume (liter) of water. The concentration of 

suspended sediment also is expressed in milligrams per liter and is based on the mass of dry 

sediment per liter of water-sediment mixture.

million gallons per day  The total volume 

of water represented by flow over a 24-hour 

period of time. Expressed as a rate, it is the 

volume of water per unit time (that is, seconds, 

minutes, or hours) that if held constant, would 

represent a flow for a 24-hour period. One 

Mgal/d is equivalent to 1.547 cubic feet per 

second or 0.04381 cubic meters per second.

million gallons per day per square mile  The 

average volume of water in millions of gallons 

from each square mile of area drained. The 

runoff is assumed to be distributed uniformly in 

time and area. See also annual runoff

minimum reporting level (MRL)  The smallest measured concentration of a constituent 

that may be reliably reported by using a given 

analytical method.

N

National Geodetic Vertical Datum of 1929

(NGVD 29)  A fixed reference adopted as 

a standard geodetic datum for elevations 

determined by leveling. It formerly was 

called “Sea Level Datum of 1929” or “mean 

sea level.” Although the datum was derived 

from the mean sea level at 26 tide stations, it 

does not necessarily represent local mean sea 

level at any particular place. See also NOAA 

Web site: http://www.ngs.noaa.gov/faq.

shtml#WhatVD29VD88, and North American 

Vertical Datum of 1988

North American Datum of 1983 (NAD 83)  The 

horizontal control datum for the United States, 

Canada, Mexico, and Central America that 

is based on the adjustment of 250,000 points 

including 600 satellite Doppler stations that 

constrain the system to a geocentric origin. 

NAD 83 has been officially adopted as the legal 

horizontal datum for the United States by the 

Federal government.

P

parameter code  A five-digit number used in 

the USGS computerized data system, National 

Water Information System, to uniquely identify 

a specific constituent or property.

particle size  The diameter, in millimeters, of 

a particle determined by sieve methods.

pesticides  Chemical compounds used to control undesirable organisms. Major categories 

of pesticides include insecticides, miticides, 

fungicides, herbicides, and rodenticides.

pH of water  The negative logarithm of the 

hydrogen-ion activity. Solutions with pH less 

than 7.0 standard units are termed “acidic,” and 

solutions with a pH greater than 7.0 are termed 

“basic.” Solutions with a pH of 7.0 are neutral. The presence and concentration of many 

chemical constituents commonly dissolved in 

water are affected, in part, by the hydrogen-ion 

activity of water. Biological processes including growth, distribution of organisms, and toxicity of the water to organisms also are affected, 

in part, by the hydrogen-ion activity of water.

polar pesticides  Pesticides that are very 

water soluble and tend not to be adsorbed onto 

soil. These pesticides are also not very soluble 

in tissues and tend not to bioconcentrate in 

biota because of their low solubility.

precipitation  Falling products of water-vapor 

condensation in the atmosphere, such as rain, 

snow, sleet, and hail.

S

sea level  As used in this report, refers to one 

of the two commonly used national vertical 

datums (NGVD 1929 or NAVD 1988). See 

separate entries for definitions of these datums. 

See data-statement conversion in the table page 

for identification of the datum used in this 

report.

sediment  Solid material that originates 

mostly from disintegrated rocks; when transported by, suspended in, or deposited from 

water, it is referred to as “fluvial sediment.” 

Sediment includes chemical and biochemical 

precipitates and decomposed organic material, 

such as humus. The quantity, characteristics, 

and origin of sediment in streams are affected 

by environmental and land-use factors. Some 

major factors are topography, soil characteristics, land cover, and depth and intensity of 

precipitation.

specific conductance (conductivity)  A 

measure of the capacity of water (or other 

media) to conduct an electrical current. It is 

expressed in microsiemens per centimeter 

at 25°C. Specific electrical conductance is a 

function of the types and quantity of dissolved 

substances in water and can be used for 
approximating the dissolved solids content 

of the water. Commonly, the concentration of 

dissolved solids (in milligrams per liter) is from 

55 to 75 percent of the specific conductance 

(in microsiemens). This relation is not constant 

from stream to stream and may vary in the 

same source with changes in the composition 

of the water.

stage  The water-surface altitude in feet above 

the datum. If the water surface is below the 

datum, the stage is negative.

stage-discharge relation  The relation 

between the water-surface altitude, called stage 

(gage height), and the volume of water flowing 

in a channel per unit time.

streamflow  The discharge that occurs in 

a natural channel. Although the term “discharge” can be applied to the flow of a canal, 

the word “streamflow” uniquely describes the 

discharge in a naturally flowing stream. The 

term “streamflow” includes sources of water in 

addition to “runoff,” and applies to discharge 

affected by diversion or regulation.

streamflow-duration percentiles  Values 

on a scale of 100 indicating the percentage 

of time during which a flow is not exceeded. 

For example, the 90th percentile of river flow 

is greater than or equal to 90 percent of all 

recorded flow rates.

suspended  As used in tables of chemical 

analyses, undissolved material in a water-sediment mixture. It is defined operationally as the 

material retained when environmental water 

samples are processed through a 0.45-micrometer filter.

suspended sediment  The sediment that is 

maintained in suspension by the turbulent 

upward components of currents or that exists in 

suspension as a colloid. See also sediment

suspended-sediment concentration  The 

velocity-weighted concentration of suspended 

sediment in the sampled zone (from the water 

surface to a point approximately 0.3 foot 

above the bed) expressed as milligrams of dry 

sediment per liter of water-sediment mixture. 

The analytical technique uses the mass of all 

the sediment and the net weight of the watersediment mixture in a sample to compute the 

suspended-sediment concentration. See also

sediment and suspended sediment

T

total discharge  The quantity of a given constituent, measured as dry mass or volume, that 

passes a stream cross section per unit of time. 

When referring to constituents other than water, 

this term needs to be qualified, such as “total 

sediment discharge,” “total chloride discharge,” 

and so on.

total recoverable  The amount of a given constituent in a whole-water sample after a sample 

has been digested (usually using a dilute acid 

solution) that results in dissolution of only 

readily soluble substances. Complete dissolution of all particulate matter is not achieved by 

the digestion treatment, and thus the determination represents something less than the 

total amount (that is, less than 95 percent) of 

the constituent present in the dissolved and 

suspended phases of the sample. To achieve 

comparability of analytical data for wholewater samples, equivalent digestion procedures 

are required of all laboratories performing such 

analyses because different digestion procedures 

may produce different analytical results.

traceable thermometer  A thermometer that 

has been found to conform to specific requirements of construction and accuracy.

turbidity  An optical property of a liquid that 

causes light rays to be scattered and absorbed 

rather than transmitted in straight lines through 

water. Turbidity, which can make water appear 

cloudy or muddy, is caused by the presence of 

suspended and dissolved matter, such as clay, 

silt, finely divided organic matter, plankton and 

other microscopic organisms, organic acids, 

and dyes (ASTM International, 2003). The 

color of water, whether resulting from dissolved 

compounds or suspended particles, can affect 

a turbidity measurement. To ensure that USGS 

turbidity data can be understood and interpreted 

properly within the context of the instrument 

used and site conditions encountered, data from 

each instrument type are stored and reported in 

the USGS National Water Information System 

by using parameter codes and measurement 

reporting units that are specific to the instrument type, with specific instruments designated 

by the method code. Specific reporting units 

used in this report are as follows:

NTUR (Nephelometric Turbidity

Units)  White or broad band [400–680 nm] 

light source, 90 degree detection angle, multiple detectors with ratio compensation.
FNU (Formazin Nephelometric Units)  Near 

infrared [780–900 nm] or monochrome light 

source, 90 degree detection angle, one detector.

FNMU (Formazin Nephelometric Multibeam

Units)  Near infrared [780–900 nm] or 

monochrome light source, multiple light 

sources, detectors at 90 degrees and possibly 

other angles to each beam. For more information please see Anderson (2004).

W

water year  In USGS reports dealing with 

surface-water supply, the 12-month period 

October 1 through September 30. The water 

year is designated by the calendar year in which 

it ends and which includes 9 of the 12 months. 

Thus, the year ending September 30, 2005, is 

called the “2005 water year.”