Minimum

25th percentile

75th percentile

Median

 Maximum

Mean

90th percentile

10th percentile

EXPLANATION

Ca

-6

-5

-4

-3

-2

-1

100

101

102

103

104

105

10

10

10

10

10

10

CONCENTRATION, IN MILLIGRAMS PER LITER

Mg

K

Na

CaCO3

Cl

SO4

N

P

Cd

Cr

Cu

Fe

Pb

Mn

Ni

Zn

PAHs

Phthalates

Suspended 

 sediment

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2009–5269

Prepared in cooperation with the U.S. Department of Transportation Federal Highway

Administration and the Massachusetts Department of Transportation

Quality of Stormwater Runoff Discharged from 

Massachusetts Highways, 2005–07

FHWA

U.S. Department of Transportation
Cover. Distribution of event-mean concentrations for selected constituents in approximately 140 composite samples of 

highway runoff collected at 12 highway-monitoring stations on 8 highways in Massachusetts; background photograph of 

rush-hour traffic on Interstate 95 in Lexington by Kimberly W. Campo, U.S. Geological Survey.
Quality of Stormwater Runoff Discharged 

from Massachusetts Highways, 2005–07

By Kirk P. Smith and Gregory E. Granato

Prepared in cooperation with the U.S. Department of Transportation Federal 

Highway Administration and the Massachusetts Department of Transportation

Scientific Investigations Report 2009–5269

U.S. Department of the Interior

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

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2010

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod

To order this and other USGS information products, visit http://store.usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

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., and Granato, G.E., 2010, Quality of stormwater runoff discharged from Massachusetts highways, 

2005–07: U.S. Geological Survey Scientific Investigations Report 2009–5269, 198 p.
iii

PREFACE

Knowledge of the characteristics of highway runoff (concentrations of constituents and the 

physical and chemical processes which produce this runoff) is important for decision makers, 

planners, and highway engineers to assess and mitigate possible adverse impacts of highway 

runoff on the Nation’s receiving waters. In 2004, the Federal Highway Administration, the 

Massachusetts Department of Transportation, and the U.S. Geological Survey began an investigation to characterize the concentrations of selected dissolved major ions, total nitrogen and 

phosphorus, selected total-recoverable metals, suspended sediment, and semivolatile organic 

compounds measured in flow-weighted composite samples of stormwater collected from typical 

highway-drainage conveyance structures on eight highways in Massachusetts during a 2-year 

sampling period. 

Office of Natural Environment

Federal Highway Administration

55 Broadway, 10th Floor

Cambridge, MA 02142

Massachusetts Department of Transportation

10 Park Plaza

Boston, MA 02116

U.S. Geological Survey

10 Bearfoot Road

Northborough, MA 10532
iv

THIS PAGE INTENTIONALLY LEFT BLANK
v

Contents

Preface ...........................................................................................................................................................iii

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

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

Purpose and Scope ..............................................................................................................................3

Site Selection..................................................................................................................................................3

Methods...........................................................................................................................................................9

Continuous Monitoring of Highway Drainage Systems .................................................................9

Design of Highway-Drainage Monitoring Systems................................................................9

Calculation of Discharge ............................................................................................................9

Calculation of Runoff Coefficients .....................................................................................................9

Calculation of Event-Mean Values of Specific Conductance .....................................................12

Collection and Analysis of Samples ................................................................................................12

Samples of Highway Runoff.....................................................................................................12

Sample Populations..........................................................................................................18

Selection of Storms ..........................................................................................................18

Sample Collection.............................................................................................................18

Sample Processing...........................................................................................................25

Sample Analysis................................................................................................................25

Samples of Highway-Runoff Sediment ..................................................................................25

Sample Collection and Processing................................................................................25

Sample Analysis................................................................................................................26

Samples of Background Soil, Highway-Berm Soil, and Other Miscellaneous

Materials........................................................................................................................26

Sample Collection.............................................................................................................26

Sample Processing...........................................................................................................26

Sample Analysis................................................................................................................27

Estimation of Constituents Contributed to Runoff from Road Salt..............................................27

Data Quality...................................................................................................................................................30

Continuous Measurements...............................................................................................................30

Chemical Quality of Water Samples ................................................................................................31

Field Quality-Control Samples .................................................................................................31

Field-Blank Samples.........................................................................................................31

Replicate Samples............................................................................................................33

Field-Spiked and Replicate Field-Spiked Samples......................................................38

Laboratory Quality Assurance and Quality-Control Samples.............................................38

Laboratory Spiked Samples ............................................................................................43

Surrogate-Compound Recovery.....................................................................................43

Laboratory-Blind Samples...............................................................................................44

Sampling Methods, Chemical Quality, and Particle Size for Suspended Sediment and

Soil Samples...........................................................................................................................44

Effectiveness of Sampling Methods for Suspended Sediment..........................................44

Automated Collection of Samples of Suspended Sediment, Controlled

Experiment............................................................................................................44
vi

Automated Collection of Samples of Suspended Sediment, Field Experiment......45

Sample Splitting ................................................................................................................49

Chemical Quality and Particle Size of Suspended Sediment, Soil Samples, and

Other Miscellaneous Samples...................................................................................51

Reference Samples ..........................................................................................................51

Replicate Samples............................................................................................................54

Particle Size.......................................................................................................................54

Quality of Highway Runoff..........................................................................................................................54

Intrasite Evaluation of Constituents in Samples of Runoff from the Principal Highways.......56

Intersite Evaluation of Constituents in Runoff from Test Highways and Principal

Highways ................................................................................................................................59

Inter-Site Evaluation of Constituents in Samples of Runoff from the Principal Highways .....65

Relation of Constituents to Annual Average Daily Traffic............................................................69

Estimated Concentrations of Major Constituents in Road Salt...................................................70

Evaluation of Constituents in Seasonal Samples of Runoff from the Principal Highways .....76

Comparison of Historical and Concurrent Data Sets.............................................................................81

Sources of Highway-Runoff Constituents ...............................................................................................85

Common Highway Constituents .......................................................................................................85

Other Anthropogenic and Natural Organic Compounds..............................................................96

Relations of Concentrations of Selected Elements and Organic Compounds to Suspended

Sediment..........................................................................................................................................96

Highway-Runoff Database and Runoff Model Overview ....................................................................101

Summary and Conclusions.......................................................................................................................103

Methods..............................................................................................................................................103

Data Quality........................................................................................................................................105

Quality of Highway Runoff...............................................................................................................106

Evaluation of Highway Runoff................................................................................................106

Relation of Constituents to Annual Average Daily Traffic Volume...................................108

Highway Winter Maintenance Materials and Data Seasonality.....................................108

Comparison of Historical Data and Concurrent Data Sets ........................................................109

Sources of Highway-Runoff Constituents ....................................................................................109

Suspended Sediment as a Surrogate for Highway-Runoff Constituents ................................110

Highway-Runoff Database ..............................................................................................................110

Data Application................................................................................................................................111

Acknowledgments.....................................................................................................................................111

References Cited........................................................................................................................................111

Appendix 1. Highway-Runoff Database (HRDB Version 1.0.0a)............................................CD-ROM
vii

Figures

1. Map of locations of highway-monitoring stations and U.S. Environmental

Protection Agency level III ecoregions in Massachusetts ...................................................5

2. Map of locations of highway-monitoring stations and surficial geology of

Massachusetts..............................................................................................................................7

3. Photograph showing a catch basin at the highway-monitoring station on Interstate

495 being cleaned by Massachusetts Department of Transportation personnel with

a vacuum truck prior to the start of monitoring.....................................................................10

4. Photograph showing a typical highway-monitoring station used to collect

measurements of water level, water temperature, air temperature, specific

conductance, and rainfall, and composite samples of highway runoff ............................11

5. Photograph showing sand debris around a catch basin on Route 2 in Littleton,

Massachusetts, that may divert highway runoff to the next downgradient catch

basin..............................................................................................................................................13

6. Graphs showing (A) percentage of storms for which antecedent dry periods were

equaled or exceeded in relation to the antecedent dry periods for storms during

which runoff samples were collected from monitoring stations on Route 119,

Ashburnham, Massachusetts, 2005–07; (B) percentage of storms for which the

event-mean values of specific conductance were calculated from continuous

records of flow and specific conductance in relation to specific conductance

measured in runoff samples collected from the monitoring stations on Route 119,

Ashburnham, Massachusetts, 2005–07 ..................................................................................19

7. Graphs showing (A) percentage of storms for which antecedent dry periods were

equaled or exceeded in relation to the antecedent dry periods for storms during

which runoff samples were collected from monitoring stations on Route 2 in

Littleton, Massachusetts, 2005–07; (B) percentage of storms for which the

event-mean values of specific conductance were calculated from continuous

records of flow and specific conductance in relation to specific conductance

measured in runoff samples collected from the monitoring stations on Route 2 in

Littleton, Massachusetts, 2005–07...........................................................................................20

8. Graphs showing (A) percentage of storms for which antecedent dry periods were

equaled or exceeded in relation to the antecedent dry periods for storms during

which runoff samples were collected from monitoring stations on Interstate 495 in

Boxborough and Bolton, 2005–07; (B) percentage of storms for which the

event-mean values of specific conductance were calculated from continuous

records of flow and specific conductance in relation to specific conductance

measured in runoff samples collected from the monitoring stations on Interstate

495 in Boxborough and Bolton, Massachusetts, 2005–07....................................................21

9. Graphs showing (A) percentage of storms for which antecedent dry periods were

equaled or exceeded in relation to the antecedent dry periods for storms during

which runoff samples were collected from monitoring stations on Interstate 95 in

Lexington and Waltham, Massachusetts, 2005–07; (B) percentage of storms for

which the event-mean values of specific conductance were calculated from

continuous records of flow and specific conductance in relation to specific

conductance measured in runoff samples collected from the monitoring stations

on Interstate 95 in Lexington and Waltham, Massachusetts, 2005–07..............................22

10. Box plot showing distribution of precipitation totals greater than 0.10 inch recorded

by the National Climatic Data Center near Worcester, Massachusetts, and of

precipitation totals for storms during which samples were collected at each of the

primary highway sites in Massachusetts, 2005–07...............................................................23
viii

11. Graph showing results of a statistical resampling experiment indicating 

uncertainty in the median of event-mean concentrations of suspended sediment

using a set of 20 randomly selected sample subpopulations ranging from 3 to

48 samples ...................................................................................................................................23

12. Photograph showing a static mixer mounted in a cut-out section of

12-inch-diameter plastic pipe...................................................................................................24

13. Graph showing relation of (A) flow-weighted specific conductance values

estimated from continuous records of flow and specific conductance to measured 

event-mean specific conductance of composite samples of highway runoff

collected at 12 monitoring stations on 8 highways for paired events, and (B) relative 

error between event-mean specific conductance and estimated values of

event-mean specific conductance in three ranges..............................................................32

14. Photographs showing test pipe and sampling equipment (top) where the static

mixer assembly was tested; (lower left) looking upstream; and (lower right)

turbulence created by the static mixer at the sampler intake location.............................46

15. Bar chart showing sediment particles greater than 0.250 millimeters in diameter 

collected by an automatic sampler with the intake mounted to a static mixer over a 

range of artificial flows in relation to the percentage of the total mass of sediment 

particles greater than 0.250 millimeters in diameter collected at the end of the 

test pipe........................................................................................................................................47

16. Photograph showing plankton net attached to the outfall of the primary

highway-runoff monitoring site on Interstate 495, Boxborough, Massachusetts ...........48

17. Photograph showing ruts on the roadway surface running parallel with the road

that often caused small flows to bypass the catch basin at the secondary

highway-monitoring station on Route 119 in Ashburnham, Massachusetts ....................58

18. Boxplots showing distribution of concentrations of selected constituents in

samples of soil collected in the vicinity of seven highway-runoff monitoring sites in

Massachusetts, 2005–07 ...........................................................................................................60

19. Graph showing relation of the percentage of impervious area within a 1-mile radius

around each of the 12 highway-runoff monitoring sites in Massachusetts to the

median concentration of suspended sediment and annual average traffic volumes.....67

20. Boxplots showing concentrations of selected constituents in samples of highway

runoff collected at eight highway-monitoring stations in Massachusetts in relation

to the annual average daily vehicles per travel lane............................................................71

21. Graph showing percentage of event-mean concentrations of chloride estimated

from continuous records of specific conductance for 1,381 runoff events from

11 highway-monitoring stations on 7 highways in Massachusetts to measured

concentrations of chloride in composite samples of highway runoff ...............................76

22. Graph showing probability distribution for loads of chloride estimated from

continuous records of specific conductance for 1,381 runoff events from 11

highway-monitoring stations on 7 highways in Massachusetts ........................................77

23. Photograph showing a snow bank along the guard rail near the highway-monitoring

station on Route 119, in Ashburnham, Massachusetts ........................................................82

24. Bar chart showing concentrations of total-recoverable metals in three particle-size

ranges of suspended sediment in samples of highway runoff collected by

automatic samplers at the principal highways in Massachusetts, 2005–07 ....................91

25. Boxplot showing distribution of concentrations of selected constituents measured

in samples of berm material from four principal highways and in samples of

highway-maintenance sand, and estimated concentrations of berm material

derived from samples of suspended-sediment quality and particle size in

Massachusetts, 2005–07 ...........................................................................................................92
ix

26. Bar chart showing the distribution of concentrations for selected polyaromatic

hydrocarbons in two particle-size ranges for suspended sediment in samples

of highway runoff collected by automatic samplers at the principal highways in

Massachusetts, 2005–07 ...........................................................................................................97

27. Scatter plot for (A) concentrations of total-recoverable copper in samples of

highway runoff collected from eight stations on four highways in Massachusetts

in relation to concentrations of total-recoverable copper estimated on the basis of

the concentration of total-recoverable copper associated with three particle-size

ranges in sediment collected from composite samples of highway runoff and the

concentration and particle-size distribution of suspended sediment in the

respective samples of highway runoff, and (B) distribution of absolute error

between estimated concentrations of total-recoverable copper and measured

concentrations of total-recoverable copper in samples of highway runoff,

Massachusetts, 2005–07 .........................................................................................................100

28. Pie charts showing the summary of the highway-runoff data including (A) a count

of sites, storms, and event-mean concentration values in the database, and

the percentage of (B) sites, (C) storm events, and (D) event-mean concentration

values in each highway-runoff data set ...............................................................................104

29. Scatter plot showing temporal distribution of storm sampling dates for each data

set in the highway-runoff database.......................................................................................105
x

Tables

1. Names, locations, and other highway attributes for U.S. Geological Survey

monitoring stations in Massachusetts......................................................................................4

2. Land-use characteristics for a one-half mile radius around each of the 12

highway-monitoring stations in Massachusetts .....................................................................8

3. Physical characteristics of, and constituents analyzed in, samples of highway

stormwater collected in Massachusetts during 2005–07 with respective long-term

method detection limits, analytical techniques, and Chemical Abstract Service

numbers........................................................................................................................................14

4. Anthropogenic organic compounds in unfiltered samples of highway runoff

determined by solid-phase extraction and capillary-column gas

chromatography/mass spectrometry, and respective long-term method detection

limits in micrograms per liter and CAS numbers...................................................................16

5. Theoretical conductance at infinite dilution, regression equation coefficients

(equations 4 and 5), the standard error of the estimate, nonparametric coefficients

of efficiency, and the median milliequivalent ratio to chloride for major ions in

solution measured at highway sites in Massachusetts, 2005–07.......................................28

6. Regression equation coefficients and nonparametric coefficients of efficiency for

measured specific conductance to concentrations for sodium, calcium, chloride,

and sulfate measured in composite samples of highway runoff for 12 sites in

Massachusetts, 2005–07 ...........................................................................................................30

7. Summary for contamination bias expected in 10 percent of samples of highway

runoff collected in Massachusetts, 2005–07..........................................................................34

8. Replicate sample statistics for seven organic compounds determined by methylene

chloride extraction and gas chromatograph/mass spectrometry analysis and by

continuous liquid-liquid extraction and capillary-column gas chromatography/mass

spectrometry analysis for 14 samples of highway runoff collected in

Massachusetts, 2005–07 ...........................................................................................................38

9. Recovery statistics for total-recoverable metals, polyaromatic hydrocarbons, and

phthalate esters in laboratory-spiked preparation samples, field-spiked samples,

and field-replicate-spiked samples and p values for Mann-Whitney tests between

laboratory spiked preparation samples and field spiked samples for the study in

Massachusetts, 2005–07 ...........................................................................................................39

10. Recovery statistics for selected natural and anthropogenic organic compounds in

laboratory-spiked preparation samples, a single field-spiked sample, and a single

replicate field-spiked sample for the study in Massachusetts, 2005–07...........................41

11. Results of field tests of paired samples of suspended sediment greater than 0.250

millimeters in diameter in highway runoff collected by a plankton net and an

automatic sampler used in conjunction with a static mixer for the total

flow-weighted mass of sediment collected at the end of a pipe at the primary

station on Interstate 495, in Boxborough, Massachusetts, 2005–07..................................49

12. Concentrations of constituents measured in samples of solids with diameters

ranging from 0.250 millimeter to 6.0 millimeters collected from a plankton net at the

outfall of the primary station on Interstate 495 in Massachusetts, 2005–07.....................50

13. Means and relative standard deviations for 14 sequential replicate samples

analyzed for concentrations of suspended sediment in an experiment to assess

the precision of field-splitting methods used in this highway-runoff study in

Massachusetts, 2005–07 ...........................................................................................................51
xi

14. Median values and relative standard deviations for selected concentrations of

total and total-recoverable metals in quality-control samples consisting of National

Institute of Standards and Technology standard reference soil ........................................53

15. Relative percent differences between 17 replicate pairs for samples of background

soils, highway-berm soils, suspended sediment, and other miscellaneous samples

collected from and near highways in Massachusetts, 2005–07.........................................55

16. Physical properties and concentrations of dissolved major ions, total nutrients,

total-recoverable metals, polyaromatic hydrocarbons, phthalate esters, and

suspended sediment in stormwater composite samples of highway runoff collected

from 12 stations on 8 highways in Massachusetts, 2005–07.............................................119

17. Physical properties and concentrations of anthropogenic and natural organic

compounds in unfiltered composite samples of highway runoff collected during

three storms from five highways in Massachusetts, 2006–07 ..........................................167

18. Concentrations of 32 elements and total organic carbon in samples of sieved 

suspended sediment, highway maintenance sand, road salt, roadside grasses, and

dry pine needles collected from four highways in Massachusetts, 2005–07.................178

19. Distribution of particle sizes and concentrations of 32 elements measured in

samples of soil collected near seven highways in Massachusetts, 2005–07 ................185

20. Distribution of particle sizes and concentrations of 32 elements measured in

samples of berm material collected at the edge of the pavement for four highways

in Massachusetts, 2005–07 .....................................................................................................191

21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds

in samples of suspended sediment, roadside grasses, and dry pine needles

collected from four highways in Massachusetts, 2005-07 ................................................194

22. Resultant p values for Mann-Whitney tests for paired populations of constituent

concentrations for highway runoff collected from the primary and secondary

stations on four principal highways in Massachusetts, 2005–07 .......................................57

23. Resultant p values for Mann-Whitney tests for paired populations of constituent

concentrations in highway runoff collected from three stations on principal

highways and four stations on the test highways in Massachusetts, 2005–07 ...............64

24. Median and interquartile values and resultant p values for Mann-Whitney tests

at a 95-percent confidence interval for paired populations of constituent

concentrations in highway runoff collected from Interstate 93 in Massachusetts in

1999 through 2000 and 2006 through 2007...............................................................................66

25. Resultant p values for Mann-Whitney tests for paired populations of

concentrations of highway-runoff constituents collected from the primary and

secondary stations on the four principal highways in Massachusetts, 2005–07 ............68

26. Frequency of detection for selected polyaromatic hydrocarbons and

phthalate compounds in composite samples of highway runoff collected from the

four principal highways at eight sites in Massachusetts, 2005–07....................................72

27. Resultant test and p values for Kendall Tau and Spearman Rank correlation tests

performed on median values of populations of constituent concentrations in

highway runoff and annual average daily traffic volumes for the principal

highways in Massachusetts, 2005–07.....................................................................................73

28. Selected statistics for populations of concentrations of chloride, sodium, calcium,

and sulfate estimated from event-mean values of specific conductance calculated

from continuous measurements of flow and specific conductance for the period of

record for 11 highway monitoring stations in Massachusetts, 2005–07 ...........................74
xii

29. The ratio of mean concentrations of total nutrients, total-recoverable metals, and

suspended sediment in composite samples of highway runoff collected during

winter storms to mean concentrations of the respective constituents in samples

collected during non-winter storms for the primary and secondary stations on four

principal highways in Massachusetts, 2005–07 ....................................................................77

30. Resultant p values for single-tail Mann-Whitney tests between paired populations

of winter and non-winter concentrations of constituents in highway runoff

collected from the primary and secondary stations on the four principal highways

in Massachusetts, 2005–07 .......................................................................................................79

31. Concentrations of selected constituents measured in a sample of liquid calcium

chloride collected at the highway-service depot near Interstate 95, Lexington,

Massachusetts and diluted to 3.5 percent by mass and the ratio of the

concentration of each constituent to the concentration of chloride.................................80

32. Median of event-mean concentrations and 90-percent confidence interval for

selected constituents in samples of highway runoff collected during this study,

historical highway studies, and other recent studies for highways with annual

average daily traffic volumes of 30,000 to 85,000 vehicles ..................................................83

33. Pearson correlation coefficients for total nutrients, total-recoverable metals, and

polyaromatic hydrocarbons in samples of highway runoff collected from Interstate

95 in Lexington and Waltham, Massachusetts, 2005–07......................................................86

34. Median ratios between selected polyaromatic hydrocarbons in composites of

highway runoff for eight highways in Massachusetts, 2005–07, and ratios for

common sources of polyaromatic hydrocarbons found in highway runoff......................88

35. Frequency of detection, frequency of detection greater than or equal to the

long-term method detection level, and possible sources of selected anthropogenic

and natural organic compounds in 15 composite samples of highway runoff

collected at 5 sites in Massachusetts, 2006–07 ....................................................................98

36. Statistics for concentrations of selected constituents estimated on the basis of

the concentration of suspended sediment for three particle-size ranges in 105

samples of highway runoff and for concentrations of the constituents measured

in samples of suspended sediment for equivalent particle sizes collected from the

principal highways in Massachusetts, and the differences between the estimated

concentrations and the measured concentrations in composite samples of

highway runoff ..........................................................................................................................102
xiii

Conversion Factors and Abbreviations

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2

) 929.0 square centimeter (cm2)

square foot (ft2

) 0.09290 square meter (m2)

square inch (in2

) 6.452 square centimeter (cm2)

square mile (mi2

) 259.0 hectare (ha)

square mile (mi2

) 2.590 square kilometer (km2) 

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3

) 

gallon (gal) 3.785 cubic decimeter (dm3

) 

million gallons (Mgal) 3,785 cubic meter (m3

)

cubic inch (in3

) 16.39 cubic centimeter (cm3) 

cubic inch (in3

) 0.01639 cubic decimeter (dm3) 

cubic inch (in3

) 0.01639 liter (L)

cubic foot (ft3

) 28.32 cubic decimeter (dm3) 

cubic foot (ft3

) 0.02832 cubic meter (m3) 

Flow rate

foot per second (ft/s) 0.3048 meter per second (m/s)

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Mass

ounce, avoirdupois (oz) 28.35 gram (g) 

pound, avoirdupois (lb) 0.4536 kilogram (kg) 

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

°F=(1.8×°C)+32

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

°C=(°F-32)/1.8

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

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).
xiv

ABBREVIATIONS AND ACRONYMS

AADT Average annual daily traffic

An Anthracene

Ba Benzo[a]anthracene

Bghi Benzo[ghi]perylene

BMP Best management practice

Chr Chrysene

DOT Department of Transportation

EMC Event-mean concentration

Fl Fluoranthene

HRDB Highway Runoff Database

Ip Indeno[1,2,3-cd]pyrene

LTMDL Long-term method detection level

NWQL National Water Quality Laboratory

PAH Polyaromatic hydrocarbon

Phe Phenanthrene

Py Pyrene 

RPD Relative percent difference

SELDM Stochastic Empirical Loading and Dilution Model

SVOC Semivolatile organic compound

TOC Total organic carbon

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey
Abstract

The U.S. Geological Survey (USGS), in cooperation with 

U.S. Department of Transportation Federal Highway Administration and the Massachusetts Department of Transportation, 

conducted a field study from September 2005 through September 2007 to characterize the quality of highway runoff for a 

wide range of constituents. The highways studied had annual 

average daily traffic (AADT) volumes from about 3,000 to 

more than 190,000 vehicles per day. Highway-monitoring 

stations were installed at 12 locations in Massachusetts on 

8 highways. The 12 monitoring stations were subdivided into 

4 primary, 4 secondary, and 4 test stations. Each site contained 

a 100-percent impervious drainage area that included two or 

more catch basins sharing a common outflow pipe. Paired primary and secondary stations were located within a few miles 

of each other on a limited-access section of the same highway. 

Most of the data were collected at the primary and secondary stations, which were located on four principal highways 

(Route 119, Route 2, Interstate 495, and Interstate 95). The 

secondary stations were operated simultaneously with the 

primary stations for at least a year. Data from the four test stations (Route 8, Interstate 195, Interstate 190, and Interstate 93) 

were used to determine the transferability of the data collected 

from the principal highways to other highways characterized 

by different construction techniques, land use, and geography.

Automatic-monitoring techniques were used to collect 

composite samples of highway runoff and make continuous measurements of several physical characteristics. Flowweighted samples of highway runoff were collected automatically during approximately 140 rain and mixed rain, sleet, 

and snowstorms. These samples were analyzed for physical 

characteristics and concentrations of 6 dissolved major ions, 

total nutrients, 8 total-recoverable metals, suspended sediment, 

and 85 semivolatile organic compounds (SVOCs), which 

include priority polyaromatic hydrocarbons (PAHs), phthalate 

esters, and other anthropogenic or naturally occurring organic 

compounds. The distribution of particle size of suspended 

sediment also was determined for composite samples of highway runoff. Samples of highway runoff were collected year 

round and under various dry antecedent conditions throughout 

the 2-year sampling period. In addition to samples of highway 

runoff, supplemental samples also were collected of sediment 

in highway runoff, background soils, berm materials, maintenance sands, deicing compounds, and vegetation matter. These 

additional samples were collected near or on the highways to 

support data analysis.

There were few statistically significant differences 

between populations of constituent concentrations in samples 

from the primary and secondary stations on the same principal 

highways (Mann-Whitney test, 95-percent confidence level). 

Similarly, there were few statistically significant differences 

between populations of constituent concentrations for the four 

principal highways (data from the paired primary and secondary stations for each principal highway) and populations 

for test stations with similar AADT volumes. Exceptions to 

this include several total-recoverable metals for stations on 

Route 2 and Interstate 195 (highways with moderate AADT 

volumes), and for stations on Interstate 95 and Interstate 93 

(highways with high AADT volumes). Supplemental data collected during this study indicate that many of these differences 

may be explained by the quantity, as well as the quality, of the 

sediment in samples of highway runoff.

Nonparametric statistical methods also were used to test 

for differences between populations of sample constituent 

concentrations among the four principal highways that differed mainly in traffic volume. These results indicate that there 

were few statistically significant differences (Mann-Whitney 

test, 95-percent confidence level) for populations of concentrations of most total-recoverable metals and organic compounds 

among the stations on the four principal highways. There were 

significant differences between most populations of concentrations in samples from Route 119 (the highway with the lowest 

AADT volume) and those from the three principal highways 

with higher AADT volumes. Nevertheless, the median concentrations and upper interquartile ranges for populations of 

many total-recoverable metals collected from the 12 stations 

increased with increasing AADT volume, indicating a positive 

correlation between the two variables. The frequency of detection for various organic compounds also increased with traffic 

volume for the four principal highways. Furthermore, results 

for Kendall’s Tau correlation coefficient and Spearman rank 

correlation coefficient tests indicate that correlations between 

the median concentrations for total nitrogen (N), total phosphorus (P), all total-recoverable metals, benzo[a]anthracene, 

Quality of Stormwater Runoff Discharged from 

Massachusetts Highways, 2005–07

By Kirk P. Smith and Gregory E. Granato
2 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

benzo[b]fluoranthene, fluoranthene, and pyrene to the respective AADT volumes of the eight highways were significantly 

different at a 95-percent confidence level.

Concentrations of nearly all constituents measured in 

samples of highway runoff in this study increased substantially 

during January 2006 through April 2006 and March 2007 

through April 2007 compared to the concentrations in samples 

collected during months without snowfall. Average concentrations of total P, total-recoverable metals, and suspended sediment in samples of highway runoff collected during the winter 

were about 3 to 11 times the average concentrations observed 

in samples of non-winter runoff. Results for single-tail MannWhitney tests of nearly all populations of constituents between 

winter composite samples and non-winter composite samples 

collected from each principal highway indicate that the winter 

concentrations were significantly higher at a 99-percent 

confidence interval. Deicing compounds, which contain trace 

amounts of total N and many total-recoverable metals, account 

for only a small fraction of the difference between winter and 

non-winter concentrations. Furthermore, results of analyses of 

1,381 runoff events indicate that estimated event-mean concentrations (EMCs) of chloride (Cl) in excess of 10,000 mg/L, 

which would contain relatively marginal amounts of N and 

many total-recoverable metals, occurs in less than about 

2 percent of the runoff events. Many of the same constituents are associated with sand applied to the highways during the winter. Data from this study indicate that highwaymaintenance sand can account for a substantial amount of the 

difference between winter and non-winter concentrations of 

P, iron (Fe), and manganese (Mn). For the monitoring stations 

on Interstate 495, highway maintenance sand was estimated 

to account for about 94, 38, and 53 percent of the increase in 

winter EMCs for total P, Fe, and Mn, respectively.

Results of principal component analysis of all data and 

data subsets for total-recoverable metals and for PAHs from 

the principal highways were inconclusive. However, the 

proportions of most highway constituents originating from 

likely sources were estimated from the ratios of certain PAH 

compounds in samples of highway runoff to known ratios of 

the same PAHs in different matrixes and from ratios of the 

dominant particulate-associated PAHs to selected elements in 

exhaust emissions. These analyses indicate that the dominant 

sources of most PAHs are consistent with automobile emissions. The source for P and most total-recoverable metals 

other than copper (Cu) and zinc (Zn) are largely local soils, 

berm materials, vegetation matter, and maintenance sands, 

and sources of Cu, Zn, and many phthalate compounds are 

likely tire and brake wear. Conservative contributions of 

P, Fe, Mn, nickel (Ni), and lead (Pb) from soils proximate 

to the highways were estimated to account for on average 

about 37 percent of the median P concentration, 53 percent 

of the median Fe concentration, 54 percent of the median Mn 

concentration, 15 percent of the median Ni concentration, and 

44 percent of the median Pb concentration in samples of highway runoff from the principal highways. Many of the SVOCs 

that were detected in samples of highway runoff in this study 

are associated with fuels, lubricants, antifreeze, windshield 

fluids, and chemical treatments of engine compartments, 

finish-paint coats, automotive panels, and other vehicle components. However, other SVOCs in the same samples indicate 

plant materials, tobacco products, wood preservatives, fecal 

bacteria, and potential leachates from highway litter, including 

compounds associated with common beverages and personalcare products.

Concentrations of suspended sediment in composite samples of highway runoff were examined as a potential surrogate 

for concentrations of sediment-affiliated constituents measured 

in samples of highway runoff. Relations between suspended 

sediment and total P, and suspended sediment and many 

total-recoverable metals indicate that it is possible to estimate 

reasonable planning-level concentrations for many constituents on the basis of the concentration of a constituent affiliated 

with suspended sediment and from the average gradated concentrations (concentrations that include suspended sediment of 

specific size ranges) of suspended sediment from the principal 

highways in this study. For many applications, the average 

gradated concentrations of suspended sediment from this study 

may be used in the absence of site-specific data because results 

of statistical tests of concentrations of suspended sediment 

among the four principal highways, and between the principal highways and most test highways, were not significantly 

different, except for Route 119, which had the lowest AADT 

volume. Relations between gradated concentrations of suspended sediment and concentrations of total P and many totalrecoverable metals also indicate that a disproportional amount 

of the concentration for most constituents is associated with 

fine-grained sediments less than 0.063 millimeters in diameter.

Introduction

Stormwater discharges from Massachusetts highways can 

adversely affect the quality of the receiving water and may 

result in the failure of a water body to meet the Massachusetts 

surface-water-quality standards. Many studies have shown that 

stormwater runoff can be a source of suspended solids, nutrients, metals, and polyaromatic hydrocarbons (Kayhanian and 

others, 2003; Smith, 2002; Breault and Granato, 2000; Davenport, 1990). The variation of contaminants in highway runoff 

is, however, poorly understood, partly because highway runoff 

is a complex mix of contaminants from multiple sources, 

including atmospheric deposition; deposition of local soils 

and automobile residuals on pavement surfaces, highway-construction residuals, and highway maintenance materials; and 

other sources. As a result, the quantity of constituents reported 

and the quality of highway runoff reported in studies may vary 

by orders of magnitude within a storm and between storms 

(Smith, 2002; Granato and Smith, 1999; Spangberg and Niemczynowicz, 1992). The wide variation of study results are also 

caused, at least in part, by inadequate or poorly documented 

data-collection methods, variation in site characteristics, and 

limited and out-of-date field data, which can lead to differ-
Site Selection 3

ent conclusions about the magnitude of the highway-runoff 

problem (Transportation Research Board, 1997).

Because little highway-runoff data have been collected 

in the northeastern United States and because the validity of 

existing data is questionable (Breault and Granato, 2000), 

the U.S. Geological Survey (USGS), in cooperation with 

the Federal Highway Administration and the Massachusetts 

Department of Transportation, began a study in September 

2004 to document the presence of a wide range of constituents 

in runoff from highways with annual average daily traffic 

(AADT) volumes ranging from about 3,000 to about 191,000 

vehicles per day.

The data presented in this report are integrated in the 

Highway-Runoff Database (HRDB Version 1.0.0a) (Granato 

and Cazenas, 2009), which serves as a preprocessor for the 

Stochastic Empirical Loading and Dilution Model (SELDM) 

(Granato, 2007). The integration of these data with a technically sound highway-runoff model can be used to guide, 

substantiate, and support highway planning, design, and maintenance decisions. The study findings may be useful toward 

meeting total maximum daily load (TMDL) requirements 

(as outlined by the National Pollutant Discharge Elimination System (NPDES) phase II program) and can aid in the 

interpretation of local, regional, and national highway-runoff 

data including flows, concentrations, loads, potential effects 

on receiving waters, and the potential effectiveness of various 

best management practices (BMPs).

Purpose and Scope

This report documents concentrations of selected dissolved major ions, total nitrogen (N) and phosphorus (P), 

selected total-recoverable metals, suspended sediment, and 

semivolatile organic compounds (SVOCs) measured in flowweighted composite samples of stormwater collected from 

typical highway-drainage conveyance structures on eight 

highways in Massachusetts during a 2-year sampling period. 

The physiochemical characteristics of samples of highway 

sediment, highway-berm soil, and local soils adjacent to the 

highways are described, and the monitoring and sample-collection methods for all data within the report are documented.

The report presents a discussion of the relation between 

populations of constituent concentration data among the 12 

highway-monitoring stations and AADT volumes. The report 

also presents the methods used to estimate event-mean concentrations (EMCs) of elements used in deicing materials from 

continuous records of flow and specific conductance, and the 

methods used to calculate planning-level estimates for various 

constituents associated with suspended sediment. Concentrations of dissolved major ions, total nutrients, total-recoverable 

metals and other elements, natural and anthropogenic organic 

compounds, and suspended sediment in highway runoff, 

roadside materials, and highway-maintenance materials are 

presented in tables and illustrations. In addition, an overview 

is presented of HRDB and SELDM.

Site Selection

A systematic approach was used to select 12 monitoring locations on 8 highways in Massachusetts. These locations were selected on the basis of published AADT volumes; 

proximity of sites to each other; similarities in surficial 

geology, soils, vegetation, and land use as identified by the 

U.S. Environmental Protection Agency (USEPA) level III 

ecoregions (U.S. Environmental Protection Agency, 2003); 

highway and drainage construction; site accessibility and 

safety; and suitability of sites for hydrologic and meteorologic 

monitoring, and collection of stormwater samples. The 12 sites 

were subdivided into 4 primary, 4 secondary, and 4 test sites 

(table 1). Most of the stormwater samples were collected at 

the primary and secondary sites, which were located on four 

principal highways in the eastern region of the State (fig. 1). 

Paired primary and secondary sites were located within a 

few miles of each other on a section of highway with limited 

access to ensure comparable levels of traffic volume and 

density. Although both the design and operation of the primary 

and secondary monitoring stations were similar, the monitoring period and number of samples of highway runoff collected 

at the primary stations were greater than at the secondary 

stations. Stormwater samples collected at the test sites were 

used to assess the transferability of the data collected from 

the principal highways to other highways that have different 

construction methods, land use, and geography.

The primary- and secondary-monitoring stations were 

located on Route 119 in Ashburnham (424209071545201 and 

42415507154320); Route 2 in Littleton (423027071291301 

and 423027071291302); Interstate 495 in Boxborough 

(422821071332001) and Bolton (422716071343901); and 

Interstate 95 in Lexington (422620071153301) and Waltham 

(422420071153302). The monitoring locations on these 

highways represent relatively low, moderate, high, and very 

high AADT volumes, respectively (table 1). These sites were 

chosen in part by analyzing available traffic volumes compiled 

by the Massachusetts Department of Transportation (DOT) 

(2007) . Because the EMCs of constituents attributed to vehicular wear and operation are functions of traffic volume, density, and the amount of stormwater, which is directly related to 

amount of highway-surface area, the number of lanes for each 

highway also was considered along with the AADT during the 

site selection. Therefore, normalized AADT volumes (AADT 

divided by the total number of lanes) that were each incrementally different by about 30 percent or more also were used for 

site selection.

The proximity of the sampling stations on the principal 

highways was an additional factor in site selection because 

the quality of highway runoff can be affected by atmospheric 

deposition, the composition of soils adjacent to the highways, 

and land-use characteristics. To determine whether populations 

of concentrations of highway-related constituents were significantly different between highways with different AADTs, 

it was important to choose sites that were close enough to 
4 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 1. Names, locations, and other highway attributes for U.S. Geological Survey monitoring stations in Massachusetts.

[USGS, U.S. Geological Survey; latitude and longitude: in degrees and decimal minutes; ADT, average daily traffic (values in parenthesis represent year of 

measurement); MPH, miles per hour; NA, not applicable; MTC, modified top course; T1TC, type one top course; OGFC, open-grade friction course; traffic 

volume source: Massachusetts Department of Transportation, 2007]

USGS station 

number Highway Town or city Sitedesignation Annual ADT Annual ADT per lane

Number of 

the total 

lanes

monitored

Latitude Longitude

424209071545201 Route 119 Ashburnham Primary 3,000 (2004) 1,500 2 of 2 42 42.155 71 54.867

423027071291301 Route 2 Littleton Primary 39,700 (2004) 9,923 2 of 4 42 30.448 71 29.223

422821071332001 Interstate 495 Boxborough Primary 81,900 (2006) 13,650 3 of 6 42 28.351 71 33.333

422620071153301 Interstate 95 Lexington Primary 154,500 (2006) 19,313 8 of 8 42 26.337 71 15.554

424155071543201 Route 119 Ashburnham Secondary 3,000 (2004) 1,500 1 of 2 42 41.917 71 54.527

423027071291302 Route 2 Littleton Secondary 39,693 (2004) 9,923 2 of 4 42 30.448 71 29.223

422716071343901 Interstate 495 Bolton Secondary 81,900 (2006) 13,650 2 of 4 42 27.267 71 34.645

422420071153302 Interstate 95 Waltham Secondary 180,600 (2000) 22,576 2 of 8 42 24.341 71 15.553

424019073062601 Route 8 North Adams Test 15,532 (2006) 3,883 4 of 4 42 40.317 73 06.433

414339070462201 Interstate 195 Marion Test 25,700 (2006) 6,425 2 of 4 41 43.65 70 46.367

423016071431501 Interstate 190 Leominster Test 41,168 (2004) 10,292 2 of 4 42 30.275 71 43.250

421647071024703 Interstate 93 Boston Test 191,000 (2004) 23,874 8 of 8 42 16.78 71 02.78

USGS Station 

number Highway Drainage area(square feet)

Posted speed

limit

(MPH)

Paved

median

Age of pavement 

at start of study 

(years)

Pavement

type

424209071545201 Route 119 26,000 50 NA 15 MTC

423027071291301 Route 2 11,500 55 Yes 15 MTC

422821071332001 Interstate 495 16,600 65 No 21 T1TC

422620071153301 Interstate 95 31,500 55 No 5 OGFC

424155071543201 Route 119 13,800 50 NA 15 MTC

423027071291302 Route 2 13,590 55 Yes 15 MTC

422716071343901 Interstate 495 17,900 65 No 21 T1TC

422420071153302 Interstate 95 12,700 55 No 12 MTC

424019073062601 Route 8 23,500 50 No 13 T1TC

414339070462201 Interstate 195 12,400 65 No 18 T1TC

423016071431501 Interstate 190 25,100 65 No 0 OGFC

421647071024703 Interstate 93 64,500 55 No 13 OGFC
Site Selection

5Figure 1. Locations of highway-monitoring stations and U.S. Environmental Protection Agency level III ecoregions in Massachusetts.

Massachusetts Turnp ki e

90

195

91

495

190

93

95

290

495

95

93

95

202

7

20

202

20

8

9

7A

2

12

57

116

3

28

28

6

62

2

105

139

128

9 9

2 3

20

20

119

6

424019073062601

424209071545201

424155071543201

423016071431501 423027071291302

422821071332001

422716071343901

422620071153301

422420071153302

421647071024703

414339070462201

423027071291301

CONNECTICUT

NEW

YORK

VERMONT NEW HAMPSHIRE

MASSACHUSETTS

RHODE

ISLAND

ALANTIC OCEAN

BOSTON HARBOR

CAP COD

MARION

LEOMINSTER

NORTH ADAMS

ASHBURHAM

BOSTON

LITTLETON

BOLTON

BOXBOROUGH LEXINGTON

WALTHAM

70° 71° 72° 73°

43°42°

Base from U.S. Environmental Protection Agency, digital data, 1:250,000, 2003Massachusetts stateplane projection, 1983 North American datumEcoregions from U.S. Environmental Protection Agency (USEPA), 2003

EXPLANATION

Carbonate bedrockUSEPA Level III Ecoregions Northeastern Highland (58) Northeastern Coastal Zone (59) Atlantic Coastal Pine Barrens (84) Eastern Great Lakes and Hudson Lowland (83)Highways Interstate U.S. highway State routeHighway Station—with station identifier Primary and secondary stations Test stations 50 MILES 0

50 KILOMETERS 0
6 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

each other that these attributes (atmospheric deposition, soils, 

and land use) were broadly similar so that a practical level 

of experimental control could be achieved. As a result, all of 

the primary and secondary monitoring stations were located 

within a 38-mi swath in eastern Massachusetts and were 

located in or near USEPA level III Northeastern Coastal Zone 

ecoregion 59 (fig. 1) in areas consisting of sand and gravel, 

till, or bedrock (fig. 2).

USEPA level III ecoregions are areas that are similar in 

geology, physiography, vegetation, climate, soils, land use, 

wildlife, and hydrology (Griffith and others, 1999). Massachusetts contains three level III ecoregions. These include ecoregion 58 (Northeastern Highlands), 59 (Northeastern Coastal 

Zone), and 84 (Atlantic Coastal Pine Barrens) (fig. 1). In 

general, ecoregion 58 is more mountainous and less populated 

than ecoregions 59 and 84. The climate, surficial geology, 

soils, vegetation, and physiography of ecoregion 84 are much 

different than those of ecoregions 58 and 59.

The highway attributes for the primary and secondary 

monitoring stations are relatively similar (table 1). The impervious drainage areas for these sites range from about 13,000 

to 31,000 ft2

. Posted speed limits range from 50 to 65 mi/h. 

The age of the pavement for the principal highways ranged 

from 5 to 21 years. The wearing surface for all highways, 

including the highways where the test sites were located, was 

constructed of bituminous concrete; however, the type of 

pavement surface varied among sites. Type I-1 top course and 

modified top course are standard wearing surfaces composed 

of a mix of a specific blend and gradation of aggregates with 

bituminous cement. The primary difference between the two 

types of pavement is the gradation of the aggregates used 

in the mix. The gravel in aggregates used in a modified top 

course is slightly coarser (95–100 percent of the gravel had a 

diameter less than or equal to 0.75 in.) than the gravel used in 

a type I-1 course (a diameter of 0.5 in.). Open-grade friction 

course (OGFC), also referred to as “popcorn pavement,” is a 

more permeable surface than the other types; the macrotexture of the OGFC pavement facilitates the drainage of water 

from the tire-pavement interface to improve tire contact with 

the pavement and reduce the potential for hydroplaning (U.S. 

Department of Transportation Federal Highway Administration, 1990). In general, the dominant land uses surrounding 

the monitoring stations on the principal highways are forested 

and residential (table 2). However, the amount of surrounding 

impervious area increased with the highway AADT because 

the larger highways are in areas that contain more residential, 

commercial, industrial, and other transportation-related land 

uses than highways with lower AADTs.

The tests sites were located on Route 8 in North 

Adams (424019073062601), Interstate 195 in Marion (414339070462201), Interstate 190 in Leominster (423016071431501), and Interstate 93 in Boston 

(421647071024703; fig. 1). Some of the characteristics of the 

test sites were similar to those of the primary and secondary 

monitoring stations with similar AADTs (tables 1 and 2); however, at least one explanatory variable at each of the test sites 

differed from that of the corresponding sites on the principal 

highways. These explanatory variables for a site include one 

or more of the following categories: pavement age, surficial 

geology, land use, and climate. The site on Route 8 in western 

Massachusetts is similar to the sites on Route 119. The site on 

Route 8 was selected because the chemistry of local soils was 

often reflected in the runoff chemistry, and a distinguishing 

feature of this part of western Massachusetts is the carbonate 

bedrock, which affects the soil characteristics of this area. The 

test site on Interstate 190 had similar AADT volume, land-use 

characteristics, and surficial geology to the sites on Route 2. 

The Interstate 190 site was selected because this section of 

Interstate 190 was resurfaced at the start of the study period 

and, therefore, provided a unique opportunity to compare 

samples of highway runoff collected from new OGFC pavement to those collected from aged pavement in a similar 

setting. The third test site was located on Interstate 195 near 

the coast in southeastern Massachusetts. This site had AADT 

volume and land-use characteristics similar to those at the sites 

on Route 2 (tables 1 and 2). This site was selected because the 

surficial materials there consist largely of sand whereas those 

at the sites on Route 2 consist mostly of till or bedrock (fig. 2). 

This location also has a slightly milder climate than elsewhere in Massachusetts, and the quality of precipitation may 

be affected as a result of the proximity to the coast. A milder 

climate may affect the level and duration of winter maintenance activities, and coastal precipitation can differ in concentrations of various constituents, including N and chloride 

(Cl) (National Atmospheric Deposition Program, 2008). The 

last test site is on Interstate 93 in Boston. Although this site 

has an AADT volume similar to those at the sites on Interstate 

95, the highway site is located in a highly urbanized area near 

the Boston Harbor. Thus, the quality of highway runoff also 

may be affected by differences in precipitation, in addition to 

differences in land use.

The suitability for hydrologic and meteorologic monitoring and for the collection of water-quality samples was the 

final factor in the selection of each site. Each site contained a 

well-defined 100-percent impervious drainage area. At each 

site, the drainage area encompassed the entire cross section 

of each highway in one or both directions, with the exception 

of the secondary site on Interstate 95. The sites selected in 

this study do not contain or receive drainage from the median 

strip, emergency pull-off areas, driveways, or parking lots. 

These features ultimately reduce chemical and hydrologic bias 

associated with local soil chemistry and extraneous drainages not characteristic of stormwater runoff from highways. 

In this study, all samples of stormwater were collected from 

the outlets of catch basins because these are commonly used 

along Massachusetts highways, provide a physical means for 

metering flows during storms, and are often the final discharge 

points to receiving water bodies.
Site Selection

7Figure 2. Locations of highway-monitoring stations and surficial geology of Massachusetts.

Massachusetts Turnp ki e

90

91

495

190 93

95

290

495

95

195

95

202

7

20

202

20

8

9

7A

2

12

57

119

3

28

28

6

2

105

9 9 128

2 3

20

20

6

424019073062601

424209071545201 424155071543201

423016071431501

422821071332001

422716071343901

423027071291302

422620071153301

422420071153302

421647071024703

423027071291301

422821071332001

422716071343901

422620071153301

422420071153302

421647071024703

414339070462201

423027071291301

70° 71° 72° 73°

43°42°

EXPLANATION

Surficial geology

Till or bedrock

 Sandy till over sand Sand and gravel deposit End moraines Large sand deposit, where distinguished from sand and gravel deposit Fine-grained deposit Flood-plain alluvium

Highways

Interstate

Carbonate bedrock 

 U.S. highway State routeHighway Station—with station identifier Primary and secondary stations Test stations

Base from Executive Office of Energy and Environmental Affairs, 1:250,000, 1999Massachusetts mainland stateplane projection. 1983 North American datum

50 MILES 0

50 KILOMETERS 0

CONNECTICUT

VERMONT NEW HAMPSHIRE

MASSACHUSETTS

RHODE

ISLAND

ALANTIC OCEAN
8 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 2. Land-use characteristics for a one-half mile radius around each of the 12 highway-monitoring stations in Massachusetts.

[Land use and total impervious area are expressed as percentages of the total area; Data source: Massachusetts GIS Land Use (1951–99) - January 2002 

accessed on March 9, 2009, at http://www.mass.gov/mgis/lus.htm]

Surrounding land use

U.S. Geological Survey station number and highway

424209071545201 424155071543201 424019073062601 423027071291301 423027071291302 423016071431501

Route 119 Route 119 Route 8 Route 2 Route 2 Interstate 190

Cropland 0.0 0.0 20.2 4.0 4.0 0.0

Commercial 0.0 0.0 6.0 0.0 0.0 0.3

Forest 85.6 91.6 44.7 69.3 69.3 64.5

Industrial 0.0 0.0 0.0 0.0 0.0 0.0

Mining 0.0 0.0 1.2 0.0 0.0 1.3

Open land 2.7 2.1 9.2 1.0 1.0 4.2

Other transportation 0.0 0.0 0.3 4.5 4.5 8.6

Parks, cemeteries, vacant

undeveloped land

0.6 0.6 14.3 0.2 0.2 0.0

Participation recreation 0.0 0.0 0.0 0.0 0.0 3.2

Pasture 0.0 0.0 0.2 1.5 1.5 4.2

Residential 0.5 0.8 2.4 10.0 10.0 10.8

Salt wetland 0.0 0.0 0.0 0.0 0.0 0.0

Water (fresh and (or) salt) 4.5 0.4 1.5 0.0 0.0 1.7

Wetland 6.1 4.4 0.0 9.3 9.3 1.2

Total impervious area 1.1 1.1 11.2 6.0 6.0 13.1

Surrounding land use

U.S. Geological Survey station number and highway

414339070462201 422821071332001 422716071343901 422620071153301 422420071153302 421647071024703

Interstate 195 Interstate 495 Interstate 495 Interstate 95 Interstate 95 Interstate 93

Cropland 0.0 1.5 1.4 1.2 0.0 0.0

Commercial 0.6 0.0 0.0 10.7 0.0 5.3

Forest 42.3 49.1 68.7 34.7 13.2 0.5

Industrial 0.7 3.4 0.0 0.0 25.2 12.8

Mining 2.1 0.9 0.0 0.0 0.0 0.0

Open land 2.0 1.4 1.1 6.1 2.5 5.2

Other transportation 12.5 8.1 8.0 12.4 6.0 13.8

Parks, cemeteries, vacant

undeveloped land

0.8 0.0 2.9 0.3 0.0 6.6

Participation recreation 0.9 0.0 0.0 0.4 0.5 2.1

Pasture 0.1 0.0 2.8 0.0 0.0 0.0

Residential 25.8 17.3 14.5 25.4 11.3 21.6

Salt wetland 0.5 0.0 0.0 0.0 0.0 12.1

Water (fresh and (or) salt) 0.0 2.1 0.0 6.7 40.5 19.9

Wetland 3.7 16.2 0.6 2.1 0.7 0.0

Total impervious area 10.1 6.3 5.3 18.5 28.6 41.4
Methods 9

Methods

This section includes a description of the design of each 

highway-monitoring station and the collection and analysis 

methods used for samples of highway runoff, sediment transported in highway runoff, background soils, berm soils, and 

other miscellaneous samples.

Continuous Monitoring of Highway Drainage 

Systems

Automatic monitoring equipment was used extensively 

to make continuous measurements of several physical characteristics and to collect composite samples of highway runoff. 

The primary monitoring stations and the monitoring station on 

Interstate 190 were operated from about April 2005 through 

September 2007, and secondary monitoring stations were 

operated for a year or more during the same period. The monitoring stations on the remaining three test sites were operated 

from December 2005 through July 2007. Prior to the monitoring period, the catch basins within the drainage area of each 

site were drained and cleaned with a vacuum truck (fig. 3). 

Runoff coefficients were calculated, in part, to determine 

practical flow thresholds for triggering the automatic samplers. 

Samples of highway runoff were collected by the automatic 

samplers on a flow-weighted basis. Finally, continuous records 

of flow and specific conductance were used to calculate an 

event-mean value for specific conductance for each storm.

Design of Highway-Drainage Monitoring 

Systems

The design of the monitoring stations at the primary 

and test sites was identical. These sites contained sensors for 

the measurement of water level, water temperature, specific 

conductance, air temperature, and rainfall. The secondary 

monitoring stations were similarly equipped; however, these 

sites did not contain sensors for measuring air temperature or 

rainfall. Measurements of water levels were made in order to 

estimate flow. Water temperature was measured to correct conductivity values to 25°C. Precipitation was measured to estimate the total runoff for the drainage area of each station. Air 

temperature was measured to determine whether the precipitation was rain or snow. Prior to the installation of equipment in 

monitoring shelters, all equipment was tested under controlled 

conditions at the USGS Massachusetts Water Science Center. Water-level sensors were tested in a stand-pipe assembly 

where the water level was artificially manipulated in the 

expected operational range, temperature sensors were tested in 

a water bath, specific conductance sensors were tested against 

laboratory standards in the range of 50 to 50,000 μS/cm, and 

rain gages were volumetrically tested.

Monitoring equipment was installed in small shelters, 

most measuring 2 × 2 × 4 ft and located near the highway 

drainage outfall and along the highway shoulder. The monitoring shelter was used to house the datalogger (the measurement, control, and data-storage module), a digital modem, 

12-volt power supply, solar regulator, and the automatic 

sampler. The assembly of a typically equipped monitoring station is shown in figure 4. Conductivity and water temperature 

probes were mounted inside each discharge pipe. A submersible water-level probe was mounted below the outlet in the 

most downstream catch basin or behind a volumetric weir 

mounted in the catch basin outlet. The submersible water-level 

probe was mounted within a perforated 3-in. diameter acrylic 

tube designed to minimize water-level fluctuations resulting from water falling in the catch basin. The air temperature 

sensor and tipping-bucket rainfall gage were mounted on a 

mast attached to the shelter and about 10 to 12 ft above ground 

surface to reduce bias from vehicular spray.

Each monitoring installation was programmed to record 

measurements every minute. Baseline data (data that are 

recorded regardless of the state of runoff), including water 

level, water temperature, specific conductance, and rainfall, 

were recorded every 2 hours. Average air temperature was 

computed from 60 consecutive 1-minute measurements and 

recorded every hour. Water level, water temperature, specific 

conductance, and rainfall were recorded on a 1-minute basis 

whenever the water level exceeded a water-level threshold or 

when rainfall was measured. Recorded values were retrieved 

automatically on a daily basis by a computer at the USGS 

Massachusetts Water Science Center. The telemetry at each 

site allowed for remote activation of the sampling algorithm 

and access to measured and recorded values.

Calculation of Discharge

Discharge from the catch basins was calculated by applying a stage-discharge relation specific to the geometry of the 

outlet of each catch basin to continuous water-level measurements recorded in the sump of the catch basin. For sites where 

calibrated weirs were not used, this relation was developed by 

simultaneously measuring pump flow with in-line flowmeters 

on as many as three 9,600-gal/h centrifugal pumps and measuring catch-basin-sump level. Paired stage and discharge values were recorded after both pump flow and catch-basin-sump 

level were stable across a range of pumping rates. This process 

was repeated until all of the pumps reached their maximum 

rate of flow. The stage-discharge relations were based on 20 or 

more discrete discharge measurements and were mathematically extended above the greatest flow rate (about 0.85 ft3

/s) 

on the basis of research performed by Lager and others (1977). 

Depending on the specific site, 80 to 100 percent of the 

recorded peak discharges were less than 0.85 ft3

/s.

Calculation of Runoff Coefficients

A runoff coefficient is the ratio of the volume of runoff 

to the volume of rainfall. Runoff coefficients for each event in 
10 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 3. A catch basin at the highway-monitoring station on Interstate 495 being cleaned by Massachusetts 

Department of Transportation personnel with a vacuum truck prior to the start of monitoring.
Methods 11

Rain gage

Air temperature

sensor

Solar array

Rain gage

Air temperature

sensor

Solar array

Instrument shelter

Enclosure containing

datalogger and

digital modem

Automatic sampler

Instrument shelter

Automatic sampler

Figure 4. A typical highway-monitoring station used to collect measurements of water level, water temperature, 

air temperature, specific conductance, and rainfall, and composite samples of highway runoff.
12 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

this study were calculated by dividing the sum of all 1-minute 

flows with instantaneous discharges greater than 0.009 ft3

/s by 

the product of the measured rain total and the drainage area 

for each respective monitoring station. These runoff coefficients were helpful in selecting appropriate flow thresholds 

for triggering the automatic samplers and identifying potential errors related to measurements of rainfall or water level. 

Ideally, the ratio of the volume of runoff to the volume of 

rainfall will range from zero (no runoff) to one (100 percent of 

the precipitation is measured in the runoff); however, runoff 

coefficients can exceed a value of one as a result of errors in 

the measurement of precipitation, flow, and (or) contributing 

area (Church and others, 1999). Runoff coefficients greater 

than one also can occur when flow from an upgradient drainage area is diverted into the drainage area of interest. This 

often results when the inlet of one or more upgradient catch 

basins is partially blocked by deposits of sand, debris, or slush 

around the catch-basin grate (fig. 5). In such cases, some or all 

of the water from a neighboring drainage area can be diverted 

to a downgradient drainage system. Similarly, obstructions to 

the inlet of catch basins in the monitored drainage area result 

in low runoff coefficients. Runoff coefficients also can be 

decreased when stormwater that leaks from the drainage area 

as a result of highway curbs that are too low or damaged is not 

measured. The point in the drainage system where runoff flow 

is measured also can affect these ratios. In this study, flows 

were measured at the outlet of the catch basins. Because runoff water leaked from the sump of many catch basins between 

storms (particularly the sites of Route 2 and Interstate 495), 

the initial volume of runoff that was required to fill the catch 

basin to the level of the outlet pipe was not measured. Runoff coefficients can vary more during the winter months on 

the basis of available snowmelt water. In mixed precipitation 

events, the removal of snow or slush from plowing operations 

serves to lower the runoff coefficient.

In large drainage areas, many of these factors tend 

to average out. For example, flow that bypasses one catch 

basin often is accounted for in the next downgradient catch 

basin, resulting in a zero net loss measurement of stormwater 

volume. However, because the drainage areas in this study 

are relativity small, a large amount of variability in the runoff 

coefficients is not unreasonable. While runoff coefficients 

are an important quality-assurance tool, they are also useful 

for estimating constituent loads in the absence of flow data. 

Specifically, flows can be estimated by multiplying the amount 

of precipitation from a nearby monitoring station by the size 

of the drainage area of interest, and finally by the runoff 

coefficient.

Calculation of Event-Mean Values of Specific 

Conductance

Specific conductance is the measure of the capacity of 

water to conduct an electrical current. The measurement is 

affected by the type and quantity of dissolved solids in water. 

Because conductivity sensors are robust and measurements of 

specific conductance are often relatively accurate under most 

conditions, continuous records of discharge and specific conductance were used in this study to supplement and expand the 

number of event-mean measurements of the physical characteristics of samples of highway runoff.

Event-mean specific conductance values were calculated 

for each highway site on the basis of calculated values of discharge and corresponding measurements of specific conductance. Specifically, for each runoff event (rain, mixed precipitation, and snowmelt) with instantaneous values of discharge 

greater than 0.009 ft3

/s, the event-mean specific conductance 

was calculated by dividing the sum of flow-weighted 1-minute 

specific conductance values (that is, the specific conductance 

multiplied by the instantaneous rate of flow) by the sum of 

the 1-minute values of flow. For values of discharge less than 

or equal to 0.009 ft3

/s, measurements of specific conductance 

were often erroneous because the water level at the location of 

measurement was too low to adequately submerse the sensor. 

Furthermore, flows less than or equal to 0.009 ft3

/s accounted 

for little of the total event flow. The accuracy of measurements 

of specific conductances depend primarily on the rate of sensor drift, sensor fouling, and debris collection. In most cases, 

corrections for fouling and drift were applied to the data to 

improve the accuracy (Wagner and others, 2006). These corrections were made on the basis of the performance of the sensor before and after sensor maintenance and by the response of 

the clean sensor after it was placed in three or more standardized conductance solutions in the field.

Collection and Analysis of Samples

Samples of highways runoff were collected automatically 

during storms and analyzed for concentrations of selected 

dissolved major ions, total N and P, selected total-recoverable 

metals, suspended sediment, and SVOCs (tables 3 and 4). 

Samples of sediment in highway runoff were sieved into 

specific particle-size ranges, and analyzed for concentrations 

of 32 total-recoverable elements, total organic carbon (TOC), 

and selected SVOCs. Samples of soil adjacent to the highways, samples of highway-berm soil, and samples of highway-maintenance materials were collected and analyzed for 

concentrations of 32 elements. Finally, miscellaneous samples 

of highway-berm vegetation and catch-basin debris greater 

than 250 micrometers in diameter were collected and analyzed 

for concentrations of 32 total-recoverable elements, TOC 

(catch-basin debris only), and selected SVOCs (highway-berm 

vegetation only).

Samples of Highway Runoff

About 140 flow-weighted composite samples of highway runoff were collected automatically throughout the year 

during rain and mixed precipitation storms from September 2005 to September 2007 at the 12 monitoring stations. 
Methods 13

Figure 5. Sand debris around a catch basin on Route 2 in Littleton, Massachusetts, that may divert highway runoff to the next 

downgradient catch basin.
14 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 3. Physical characteristics of, and constituents analyzed in, samples of highway stormwater collected in Massachusetts during 2005–07 with respective long-term method detection limits, analytical techniques, and Chemical Abstract Service numbers.—Continued [CAS, Chemical Abstract Service; μS/cm, microsiemens per centimeter at 25 degrees Celsius; LTMDL, long-term method detection limit; mg/L, milligrams per liter; NTRU, nephelometric turbidity ratio units; μg/L, micrograms per liter; IC, ion chromatograph; ICP, inductively coupled plasma; ICP-MS, inductively coupled plasma-mass spectrometry; ICP-AES, inductively coupled plasma-optical emission spectrometry; cICP-MS, collision/reaction cell inductively coupled plasma-mass spectrometry; MCEGC/MS, methylene chloride extraction and gas chromatograph/mass spectrometry; USEPA, U.S. Environ- mental Protection Agency; --, not available] Characteristic or constituent LTMDL Analytical technique Reference CAS number1 Turbidity, unfiltered, NTRU 0.05 USEPA 180.1 Anderson, 2004 -- pH in standard units 0.1 Glass electrode Wilde and others, 2006 -- Specific conductance in μS/cm 8 Wheatstone Bridge Radtke and others, 2005 -- Calcium, filtered, mg/L 0.01 ICP-AES Fishman, 1993 7440-70-2 Magnesium, filtered, mg/L 0.007 ICP-AES Fishman, 1993 7439-95-4 Potassium, filtered, mg/L 0.08 ICP-AES Fishman and Friedman,1989 7440-09-7 Sodium, filtered, mg/L 0.1 ICP-AES Fishman, 1993 7440-23-5 Alkalinity, filtered, laboratory, mg/L as calcium carbonate 5 Titration Fishman and Friedman, 1989 471-34-1 Chloride, filtered, mg/L 0.1 IC Fishman and Friedman, 1989 16887-00-6 Sulfate, filtered, mg/L 0.09 IC Fishman and Friedman, 1989 14808-79-8 Total nitrogen (nitrate + nitrite + ammonia + organic-N), unfiltered, mg/L 0.03 Alkaline persulfate digestion Patton and Kryskalla, 2003 17778-88-0 Phosphorus, unfiltered, mg/L 0.01 Alkaline persulfate digestion Patton and Kryskalla, 2003 7723-14-0 Cadmium, unfiltered, μg/L 0.02 ICP-MS Garbarino and Struzeski, 1998 7440-43-9 Chromium, unfiltered, μg/L 0.3 cICP-MS Garbarino and others, 2006 7440-47-3 Copper, unfiltered, μg/L 0.6 cICP-MS Garbarino and others, 2006 7440-50-8

Iron, unfiltered, μg/L 3 ICP-AES Garbarino and Struzeski, 1998 7439-89-6

Lead, unfiltered, μg/L 0.03 ICP-MS Garbarino and Struzeski, 1998 7439-92-1

Manganese, unfiltered, μg/L 0.3 ICP-MS Garbarino and Struzeski, 1998 7439-96-5

Nickel, unfiltered, μg/L 0.08 cICP-MS Garbarino and others, 2006 7440-02-0

Zinc, unfiltered, μg/L 1 cICP-MS Garbarino and others, 2006 7440-66-6

Fluorene, unfiltered, μg/L 0.17 MCEGC/MS Fishman, 1993 86-73-7

Acenaphthene, unfiltered, μg/L 0.14 MCEGC/MS Fishman, 1993 83-32-9

Acenaphthylene, unfiltered, μg/L 0.15 MCEGC/MS Fishman, 1993 208-96-8

Anthracene, unfiltered, μg/L 0.19 MCEGC/MS Fishman, 1993 120-12-7

Benzo[a]anthracene, unfiltered, μg/L 0.13 MCEGC/MS Fishman, 1993 56-55-3
Methods

15

Table 3. Physical characteristics of, and constituents analyzed in, samples of highway stormwater collected in Massachusetts during 2005–07 with respective long-term method detection limits, analytical techniques, and Chemical Abstract Service numbers.—Continued[CAS, Chemical Abstract Service; μS/cm, microsiemens per centimeter at 25 degrees Celsius; LTMDL, long-term method detection limit; mg/L, milligrams per liter; NTRU, nephelometric turbidity ratio units; μg/L, micrograms per liter; IC, ion chromatograph; ICP, inductively coupled plasma; ICP-MS, inductively coupled plasma-mass spectrometry; ICP-AES, inductively coupled plasma-optical emission spectrometry; cICP-MS, collision/reaction cell inductively coupled plasma-mass spectrometry; MCEGC/MS, methylene chloride extraction and gas chromatograph/mass spectrometry; USEPA, U.S. Environmental Protection Agency; --, not available]

Characteristic or constituent LTMDL Analytical technique Reference CAS number1

Benzo[a]pyrene, unfiltered, μg/L 0.16 MCEGC/MS Fishman, 1993 50-32-8

Benzo[b]fluoranthene, unfiltered, μg/L 0.9 MCEGC/MS Fishman, 1993 205-99-2

Benzo[ghi]perylene, unfiltered, μg/L 0.32 MCEGC/MS Fishman, 1993 191-24-2

Benzo[k]fluoranthene, unfiltered, μg/L 0.23 MCEGC/MS Fishman, 1993 207-08-9

Benzyl n-butyl phthalate (butylbenzyl phthalate),

unfiltered, μg/L

0.63 MCEGC/MS Fishman, 1993 85-68-7

Bis(2-ethylhexyl) phthalate, unfiltered, μg/L 0.53 MCEGC/MS Fishman, 1993 117-81-7

Chrysene, unfiltered, μg/L 0.16 MCEGC/MS Fishman, 1993 218-01-9

Dibenzo[a,h]anthracene, unfiltered, μg/L 0.35 MCEGC/MS Fishman, 1993 53-70-3

Diethyl phthalate, unfiltered, μg/L 0.31 MCEGC/MS Fishman, 1993 84-66-2

Dimethyl phthalate, unfiltered, μg/L 0.3 MCEGC/MS Fishman, 1993 131-11-3

Di-n-butyl phthalate, unfiltered, μg/L 0.44 MCEGC/MS Fishman, 1993 84-74-2

Di-n-octyl phthalate, unfiltered, μg/L 0.93 MCEGC/MS Fishman, 1993 117-84-0

Fluoranthene, unfiltered, μg/L 0.15 MCEGC/MS Fishman, 1993 206-44-0

Indeno[1,2,3-cd]pyrene, unfiltered, μg/L 0.11 MCEGC/MS Fishman, 1993 193-39-5

Nitrobenzene, unfiltered, μg/L 0.11 MCEGC/MS Fishman, 1993 98-95-3

Phenanthrene, unfiltered, μg/L 0.16 MCEGC/MS Fishman, 1993 85-01-8

Pyrene, unfiltered, μg/L 0.18 MCEGC/MS Fishman, 1993 129-00-0

Naphthalene, unfiltered, μg/L 0.16 MCEGC/MS Fishman, 1993 91-20-3

Perylene, unfiltered, μg/L 0.2 MCEGC/MS Fishman, 1993 198-55-0

Suspended sediment, mg/L 1 Filtration/gravimetry Guy, 1969; Shreve and Downs, 2005 --

Suspended sediment gradation, percent 0.1 Filtration/sieving/gravimetry Guy, 1969; Shreve and Downs, 2005 --

1This table contains CAS Registry Numbers®, which collectively compose a Registered Trademark of the American Chemical Society. CAS recommends the verification of the CAS Registry Numbers 

through CAS Client Services.
16 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 4. Anthropogenic organic compounds in unfiltered samples of highway runoff determined by solid-phase extraction and 

capillary-column gas chromatography/mass spectrometry, and respective long-term method detection limits in micrograms per liter 

and CAS numbers.—Continued

[CAS, Chemical Abstract Service; LTMDL, long-term method detection limit]

Constituent LTMDL CAS number1

1-Methylnaphthalene 0.03 90-12-0

2,6-Dimethylnaphthalene 0.05 581-42-0

2-Methylnaphthalene 0.03 91-57-6

3,4-Dichlorophenyl isocyanate 0.06 102-36-3

3beta-Coprostanol 0.38 360-68-9

3-Methyl-1H-indole 0.07 83-34-1

3-tert-Butyl-4-hydroxyanisole 0.16 25013-16-5

4-Cumylphenol 0.13 599-64-4

4-n-Octylphenol 0.11 1806-26-4

4-Nonylphenol 1.2 84852-15-3

4-tert-Octylphenol 0.11 140-66-9

5-Methyl-1H-benzotriazole 0.35 136-85-6

Acetophenone 0.07 98-86-2

Acetyl hexamethyl tetrahydro naphthalene 0.11 21145-77-7

Anthracene 0.08 120-12-7

9,10-Anthraquinone 0.08 84-65-1

Atrazine 0.08 1912-24-9

2,2',4,4'-Tetrabromodiphenyl ether 0.1 5436-43-1

Benzo[a]pyrene 0.06 50-32-8

Benzophenone 0.1 119-61-9

beta-Sitosterol 0.11 83-46-5

beta-Stigmastanol 0.22 19466-47-8

Bis(2-ethylhexyl) phthalate (DEHP) 0.85 117-81-7

Bisphenol A 0.22 80-05-7

Bromacil 0.1 314-40-9

Caffeine 0.06 58-08-2

Camphor 0.09 76-22-2

Carbaryl 0.13 63-25-2

Carbazole 0.12 86-74-8

Chlorpyrifos 0.12 2921-88-2

Cholesterol 0.3 57-88-5

Cotinine 0.29 486-56-6

N,N-diethyl-meta-toluamide (DEET) 0.12 134-62-3

Diazinon 0.11 333-41-5

Dichlorvos 0.11 62-73-7
Methods 17

Table 4. Anthropogenic organic compounds in unfiltered samples of highway runoff determined by solid-phase extraction and 

capillary-column gas chromatography/mass spectrometry, and respective long-term method detection limits in micrograms per liter 

and CAS numbers.—Continued

[CAS, Chemical Abstract Service; LTMDL, long-term method detection limit]

Constituent LTMDL CAS number1

Diethoxynonylphenol (4-Nonylphenol diethoxylate; NP2EO) 1.2 26027-38-2

Diethoxyoctylphenol (4-tert-Octylphenol diethoxylate; OP2EO) 0.05 26636-32-8

Diethyl phthalate (DEP) 0.1 84-66-2

d-Limonene 0.02 5989-27-5

Fluoranthene 0.08 206-44-0

Hexahydrohexamethyl cyclopentabenzopyran (HHCB) 0.1 1222-05-5

Indole 0.08 120-72-9

Isoborneol 0.05 124-76-5

Isophorone 0.08 78-59-1

Isoquinoline 0.09 119-65-3

Menthol 0.05 89-78-1

Metalaxyl 0.13 57837-19-1

Methyl salicylate 0.07 119-36-8

Metolachlor 0.12 51218-45-2

Monoethoxynonylphenol (4-Nonylphenol monoethoxylate (sum of all isomers); NP1EO) 1.35 104-35-8

Monoethoxyoctylphenol (4-tert-Octylphenol monoethoxylate; OP1EO) 0.5 26636-32-8

p-Cresol 0.08 106-44-5

Pentachlorophenol 0.33 87-86-5

Phenanthrene 0.07 85-01-8

Phenol 0.07 108-95-2

Prometon 0.08 1610-18-0

Pyrene 0.08 129-00-0

Tributyl phosphate 0.11 126-73-8

Triclosan 0.09 3380-34-5

Triethyl citrate (ethyl citrate) 0.07 77-93-0

Triphenyl phosphate 0.1 115-86-6

Tris(2-butoxyethyl) phosphate 0.05 78-51-3

Tris(2-chloroethyl) phosphate 0.08 115-96-8

Tris(dichloroisopropyl) phosphate 0.05 13674-87-8

1,4-Dichlorobenzene 0.03 106-46-7

Isopropylbenzene (cumene) 0.02 98-82-8

Naphthalene 0.03 91-20-3

Tetrachloroethene 0.22 127-18-4

Tribromomethane (Bromoform) 0.03 75-25-2

1

This table contains CAS Registry Numbers®, which collectively compose a Registered Trademark of the American Chemical Society. CAS recommends 

the verification of the CAS Registy Numbers through CAS Client Services.
18 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Composite samples of runoff were collected during storms that 

represented the range of antecedent dry periods (0–45 days), 

event-mean specific conductances calculated for individual 

runoff events (figs. 6–9), and rain totals of 0.1 to 6 in. (fig. 10) 

throughout the sampling period. Water samples were analyzed 

for concentrations of selected dissolved major ions, total N 

and P, selected total-recoverable metals, suspended sediment, 

and SVOCs.

Sample Populations

Composite samples of highway runoff were collected 

during 16 to 18 storms at the primary monitoring stations, 10 

to 11 storms at the secondary monitoring stations, and 5 to 

6 storms at the monitoring stations at the test highways over 

the 2-year sampling period and analyzed for the constituents 

in table 3. For three storms, composites of highway runoff 

collected at the four primary sampling stations and at the test 

station on Interstate 93 also were analyzed for the selected 

anthropogenic and naturally occurring organic compounds 

listed in table 4 using the methods described by Zaugg and 

others (2006a). The size of the anticipated population of 

storms that would be sampled at sites on the principal highways was determined on the basis of research presented by 

Thomson and others (1997). Their concept was tested using 

EMCs of suspended sediment collected during 50 storms 

from a catch basin on Interstate 93 in Boston (Smith, 2002). 

Concentrations of suspended sediment from this data set were 

selected randomly to form 320 discrete populations ranging 

in size from 3 to 48 samples. This resulted in 20 populations 

each containing 3 samples, 20 populations each containing 6 

samples, 20 populations each containing 9 samples, and so on. 

Normalized median concentrations of suspended sediment (the 

median for each discrete population divided by the median of 

all 50 EMCs) for a randomly generated set of sub-populations 

are shown in figure 11. These data indicate that the risk of 

over- and under-estimating suspended-sediment concentrations at a site increases with fewer samples, but the risk of 

overestimating concentrations increases more rapidly because 

suspended sediment and constituents affiliated with suspended 

sediment in highway runoff are lognormally distributed. The 

range of samples collected from the sites on principal highways in this study should provide reasonable estimates of 

mean concentrations for many constituents, and the collection 

of additional samples at these highways may not necessarily 

provide greater precision. In contrast, the size of the sample 

population for the test highways is small and less precise, 

and therefore, analyses between data from the test sites and 

primary and secondary sites on the principal highways may be 

improved by collection of additional data.

Selection of Storms

Storms were selected to reflect seasonal and antecedent 

dry variations existing throughout the study period. Precipitation totals ranged from about 0.1 to 5.1 in. for storms that 

were sampled at the principal highways. In general, most of 

the storms that were sampled during this study were within the 

interquartile range of precipitation totals greater than 0.10 in. 

recorded from 1967 through 2007 by the National Climatic 

Data Center near Worcester, Massachusetts (Granato, 2007, 

fig. 10). In this study, storms are defined in terms of measured 

wet precipitation as one or more measurements of wet precipitation equal to or greater than 0.01 in. (the minimum resolution of the rain gages), separated by a period of 6 hours of 

antecedent dry time. Because some sites did not contain rain 

gages and because rain gages are susceptible to plugging from 

snow and other debris, storms are primarily defined in this 

study by a function of flow where sequential measurements of 

discharge greater than or equal to 0.01 ft3

/s are separated by 

6 hours or more of discharge less than 0.01 ft3

/s. A discharge 

of 0.01 ft3/s was chosen as a cutoff because it was the minimum value that was discernable between the presence of flow 

and no flow on the basis of the resolution of level sensor, the 

stage-discharge relation for most sites, and reliable concurrent 

measurements of specific conductance.

Sample Collection

Samples of highway runoff for the analysis of water 

chemistry and suspended-sediment concentration were collected in the outlet pipe of a single catch basin or the drainage pipe that received discharge from multiple catch basins, 

using an automatic sampler controlled by a datalogger. The 

first sample was collected when flow exceeded 0.009 ft3

/s, 

and subsequent samples were collected at flow-proportional 

intervals. Approximately 60 samples of stormwater were collected for equivalent runoff of 1 in. of rain. Flow-proportional 

thresholds, at which point the datalogger triggered the automatic water sampler, were fixed at each site throughout the 

study irrespective of expected storm characteristics; only the 

volume for each subsample was altered. Generally, a composite of stormwater consisted of multiple 220-mL aliquots; 

however, the aliquot volume for the subsamples was reduced 

for storms with forecasted rain amounts greater than 1.5 in. so 

that the total number of samples could be increased and the 

20-L sample bottle would be adequate in size to represent the 

entire storm. For small storms with forecasted rainfall amounts 

less than 0.5 in., the aliquot volume for each subsample was 

increased to ensure that sufficient water volume was collected 

to satisfy analytical requirements. Because the frequency 

of the collection of the subsamples was a function of a flow 

threshold derived from an equivalent runoff of 1 in. of rain 

from each site, the density of subsamples forming the composite of stormwater was comparable from site to site. Various 

factors were considered during the selection and construction 

of the sites to ensure the best possible performance of the 

automatic samplers. Vertical distances from fixed sampling 

points to the sampler-pump heads were within optimal suction 

limits (Bent and others, 2001) and for most sites were less 

than about 5 ft, but were as much as 8 ft for the monitoring 

station on Route 8, Interstate 93, and the primary station on 

Interstate 95. All sampler lines were mounted in a sloping 
Methods 19

Figure 6. (A) Percentage of storms for which antecedent dry periods were equaled 

or exceeded in relation to the antecedent dry periods for storms during which 

runoff samples were collected from monitoring stations on Route 119, Ashburnham, 

Massachusetts, 2005–07; (B) percentage of storms for which the event-mean values 

of specific conductance were calculated from continuous records of flow and 

specific conductance in relation to specific conductance measured in runoff samples 

collected from the monitoring stations on Route 119, Ashburnham, Massachusetts, 

2005–07.

0.01 0.1 0.5 1 2 5 10 20 30 50 60 70 80 90 95 98 99 99.5 99.9 40 0

5

10

15

20

25

30

35

40

45

50

ANTECEDENT PERIOD, IN DAYS

PERCENTAGE OF STORMS FOR WHICH THE ANTECEDENT PERIOD

 WAS EQUALED OR EXCEEDED

1

10

100

1,000

10,000

100,000

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

PERCENTAGE OF STORMS FOR WHICH THE EVENT-MEAN SPECIFIC CONDUCTANCE

 WAS EQUALED OR EXCEEDED 

0.01 0.1 0.5 1 2 5 10 20 30 50 60 70 80 90 95 98 99 99.5 99.9 40

 Probability plot for all runoff events

 Sampled runoff events

A

B
20 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 7. (A) Percentage of storms for which antecedent dry periods were equaled 

or exceeded in relation to the antecedent dry periods for storms during which 

runoff samples were collected from monitoring stations on Route 2 in Littleton, 

Massachusetts, 2005–07; (B) percentage of storms for which the event-mean values 

of specific conductance were calculated from continuous records of flow and 

specific conductance in relation to specific conductance measured in runoff samples 

collected from the monitoring stations on Route 2 in Littleton, Massachusetts, 

2005–07.

0

5

10

15

20

25

ANTECEDENT PERIOD, IN DAYS

PERCENTAGE OF STORMS FOR WHICH THE ANTECEDENT PERIOD

 WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 50 60 70 80 90 95 98 99 99.5 99.9 40

 Probability plot for all runoff events

 Sampled runoff events

1

10

100

1,000

10,000

100,000

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

PERCENTAGE OF STORMS FOR WHICH EVENT-MEAN SPECIFIC CONDUCTANCE

 WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 50 60 70 80 90 95 98 99 99.5 99.9 40

A

B
Methods 21

Figure 8. (A) Percentage of storms for which antecedent dry periods were equaled 

or exceeded in relation to the antecedent dry periods for storms during which runoff 

samples were collected from monitoring stations on Interstate 495 in Boxborough 

and Bolton, 2005–07; (B) percentage of storms for which the event-mean values of 

specific conductance were calculated from continuous records of flow and specific 

conductance in relation to specific conductance measured in runoff samples 

collected from the monitoring stations on Interstate 495 in Boxborough and Bolton, 

Massachusetts, 2005–07.

0

5

10

15

20

25

ANTECEDENT PERIOD, IN DAYS

PERCENTAGE OF STORMS FOR WHICH THE ANTECEDENT PERIOD 

WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99.5 99.9

 Probability plot for all runoff events

 Sampled runoff events

1

10

100

1,000

10,000

100,000

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

PERCENTAGE OF STORMS FOR WHICH EVENT-MEAN SPECIFIC CONDUCTANCE 

WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99.5 99.9

A

B
22 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 9. (A) Percentage of storms for which antecedent dry periods were equaled 

or exceeded in relation to the antecedent dry periods for storms during which runoff 

samples were collected from monitoring stations on Interstate 95 in Lexington and 

Waltham, Massachusetts, 2005–07; (B) percentage of storms for which the event-mean 

values of specific conductance were calculated from continuous records of flow and 

specific conductance in relation to specific conductance measured in runoff samples 

collected from the monitoring stations on Interstate 95 in Lexington and Waltham, 

Massachusetts, 2005–07.

0

5

10

15

20

25

30

35

40

ANTECEDENT PERIOD, IN DAYS

PERCENTAGE OF STORMS FOR WHICH THE ANTECEDENT PERIOD 

WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99.5 99.9

 Probability plot for all runoff events

 Sampled runoff events

1

10

100

1,000

10,000

100,000

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

PERCENTAGE OF STORMS FOR WHICH EVENT-MEAN SPECIFIC CONDUCTANCE 

WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99.5 99.9

A

B
Methods 23

Figure 10. Distribution of precipitation totals greater than 0.10 inch recorded by the National Climatic 

Data Center near Worcester, Massachusetts, and of precipitation totals for storms during which samples 

were collected at each of the primary highway sites in Massachusetts, 2005–07.

Figure 11. Results of a statistical resampling experiment indicating uncertainty in the median of event-mean concentrations 

of suspended sediment using a set of 20 randomly selected sample subpopulations ranging from 3 to 48 samples. Samples 

were collected along Interstate 93 during 50 storms (Smith, 2002). Subsample concentrations are normalized using the median 

concentration of suspended sediment for all 50 storms.

0.1

1

10

PRECIPITATION, IN INCHES

NCDC ROUTE 119 ROUTE 2 INTERSTATE

495

INTERSTATE

95

25 percentile

75 percentile

Median

 Maximum

 Minimum

EXPLANATION

Mean

0

3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

3.00

SUSPENDED SEDIMENT, NORMALIZED CONCENTRATION

NUMBER OF SAMPLES

1:1 line for normalized event-mean 

concentrations

Unshaded area shows the range of the 

normalized event-mean concentration for 

samples selected randomly for a given 

sample population

EXPLANATION
24 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

manner to allow for the complete purging and draining of 

sample water between samples. Sampler intakes were fixed 

to static mixers (fig. 12) designed specifically for this project 

at each sampling point for all sampling locations. The static 

mixer provides a secure and consistent mount for the sampler intake, reduces transport velocity, and provides agitation 

to produce a sample that represents the average concentration of suspended sediment (Smith, 2002). Sampler intakes 

were oriented in a horizontal and downstream direction. This 

configuration minimizes debris accumulation by forming a 

small eddy that captures sand particles at the intake and thus 

allows the sampler to collect a more representative sample 

of the coarse load (Edwards and Glysson, 1999). The static 

mixers were constructed from a 0.75-in. low-density polyethylene. The performance of the static mixers was evaluated at 

a test site prior to, and concurrent with, field sampling at the 

primary-monitoring station on Interstate 495. These tests were 

done to document the effectiveness of using the static mixers 

in conjunction with the automatic samplers for the collection 

of coarse particles representative of the distribution of particle 

sizes expected in the highway runoff.

Pre-cleaned wetted components for the sampling system 

were installed prior to each sampled storm. Each automatic 

sampler was configured to hold one 20-L Teflon-lined plastic 

bottle. The Teflon lining consisted of a double wall Teflon 

pouch constructed in a clean room without the use of glue or 

adhesives. The sampler’s intake lines consisted of 0.5-in. Teflon tubing attached to silicon pump-head tubing with a custom 

made Teflon discharge tube. A multi-step process was used to 

clean all wetted parts associated with the automatic sampler 

and the processing equipment before collecting trace-level 

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 overnight. 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 

Figure 12. Static mixer mounted in a cut-out section of 12-inch-diameter plastic pipe.
Methods 25

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 6 hours or more. All components were thoroughly 

rinsed with deionized water until the specific conductance of 

the waste rinse water was less that 1 μS/cm.

Sample Processing

Most samples for chemical analysis were processed 

within 12 to 24 hours of the completion of each storm in a 

mobile field unit. Subsamples for the analysis of suspended 

sediment, nutrients, metals, and SVOCs were split directly 

from the Teflon-lined bottle into laboratory designated bottles 

in a positive-pressure hood. 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-mm (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 pouch, compressing the pouch 

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 those analyzed for dissolved constituents. 

Dissolved constituents were filtered through a 600-cm capsule 

filter with a 0.45-μm pore size.

Sample Analysis

Samples to be analyzed for dissolved cations and totalrecoverable metals were preserved with Optima-grade nitric 

acid. Samples to be analyzed for total N and P were preserved 

with sulfuric acid. Other samples required no special preservation other than refrigeration. Samples collected for the 

analysis of major ions, nutrients, total-recoverable metals, and 

SVOCs were double bagged after processing and stored on ice 

for overnight delivery to the USGS National Water Quality 

Laboratory (NWQL) in Denver, Colorado, where they were 

analyzed. Samples were analyzed for concentrations of suspended sediment and distribution of particle size at the USGS 

Kentucky Water Science Center Sediment Laboratory.

Samples of Highway-Runoff Sediment

Suspended sediment, especially fine-grained suspended 

sediment, is an important transport mechanism for many elements and SVOCs in highway runoff. Several recent studies 

in Massachusetts have documented the affiliation of various 

elements and SVOCs with sediment, and the corresponding 

effect of concentrations with specific particle sizes, in samples 

of sediment collected from oil-grit separators (Smith 2002), 

streambeds (Smith 2005), and street sweepings (Breault and 

others, 2005). In general, sediment surface area and element 

concentrations tend to increase with a decrease in sediment 

grain size. To understand these relations, which are important 

to the selection and implementation of both structural and 

nonstructural BMPs to improve the quality of water discharged from highways, the relation of sediment quality to 

particle size is measured.

Samples of suspended sediment for analysis of sediment 

quality were collected as separate aliquots from the highwayrunoff composite samples that were collected during storms at 

the sites on the principal highways during the 2-year sampling 

period. These subsamples, which were separate from samples 

for the analysis of suspended-sediment concentrations, were 

wet sieved into specific particle-size ranges, and each size 

range was analyzed for concentrations of 32 inorganic elements, TOC, and selected SVOCs.

Sample Collection and Processing

Samples of sediment in highway runoff for analysis 

of sediment quality were collected during storms from the 

sites on the principal highways using automatic samplers 

and methods described earlier. Samples for highway-runoff 

sediment quality were composited from the flow-weighted 

composites of highway runoff during two separate 8 and 

9 month periods. Thus, the sediment samples represent the 

quality of suspended sediment in highway runoff during 

multiple storms. Samples were composited because of the 

relatively large amounts of sediment required by analytical 

methods; individual flow-weighted composite samples of 

highway runoff from individual storms did not contain enough 

suspended sediment for analysis. Samples of sediment were 

temporarily frozen until sufficient material was available for 

analysis. Recent tests indicate that samples of sediment can 

be stored frozen for up to a year with little degradation of the 

sample (U.S. Environmental Protection Agency, 2005), thus it 

is unlikely that the integrity of the samples was affected during 

the compositing stage.

For analysis of inorganic constituents, water containing 

sediment and obtained from composite samples of highway 

stormwater was wet-sieved through pre-cleaned 0.250-mm 

and 0.062-mm nylon-mesh sieves. The sieves were cleaned 

by immersing them in a 5-percent solution of hydrochloric 

acid for a period of about 6 hours and thoroughly rinsing them 

with deionized water. Sediment from 0.063 mm to 0.250 mm 

in diameter and sediment greater than 0.250 mm in diameter 

for each principal highway were set aside in separate clean 

polyethylene bags. Sediment particles less than 0.063 mm in 

diameter were collected in Teflon bags with native water and 

allowed to settle undisturbed in a laboratory refrigerator in the 

USGS Massachusetts Water Science Center for several days. 

After the sediment settled, the supernatant was decanted and 

discarded, and the sediment was retained for chemical analysis. Composite samples of suspended sediment to be analyzed 

for elements were collected over an 8-month period during 

2006 and 2007.
26 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

The amount of sediment required for the analysis of 

SVOCs was large, relative to the amount of available sediment in the samples, even after compositing; thus, samples of 

suspended sediment for analysis of SVOCs were sieved only 

through a pre-cleaned 0.063-mm stainless-steel sieve. The 

sieve was cleaned by immersing it in optima-grade methanol 

and thoroughly rinsing it with deionized water. Sediment 

greater than or equal to 0.063 mm in diameter from each 

principal highway was set aside in a separate pre-cleaned 

baked glass jar. Sediment particles less than 0.063 mm in 

diameter were collected in Teflon bags with native water and 

allowed to settle undisturbed in a laboratory refrigerator in 

the USGS Massachusetts Water Science Center for several 

days. After the sediment settled, the supernatant was decanted 

and discarded, and the sediment was retained for chemical 

analysis. Samples of suspended sediment for the analysis 

of SVOCs were composited over a 9-month period during 

2005 and 2006.

Sample Analysis

Samples of sediment containing particles less than 

0.063 mm in diameter, from 0.063 mm to 0.250 mm in 

diameter, and greater than or equal to 0.250 mm in diameter 

were submitted to XRAL Laboratory of Ontario, Canada, for 

analysis of 32 inorganic elements and TOC. Samples were not 

milled prior to analysis. Total-recoverable concentrations of 

inorganic constituents were determined with the use of USEPA 

method 3050B (U.S. Environmental Protection Agency, 1996) 

and ICP emission spectroscopy. Concentrations of TOC were 

determined by infrared spectroscopy. A separate set of sediment samples containing particles less than 0.063 mm in diameter and particles greater than or equal 0.063 mm, in diameter 

was submitted to the USGS NWQL in Denver, Colorado, for 

analysis of organic compounds by accelerated solvent extraction and gas chromatography (Zaugg and others, 2006b).

Samples of Background Soil, Highway-Berm 

Soil, and Other Miscellaneous Materials

Samples of background soil, highway-berm soil, 

and highway-maintenance materials were collected and 

analyzed for concentrations of 32 inorganic elements. 

Samples of highway-berm vegetation and catch-basin debris 

greater than 250 micrometers also were collected and analyzed for concentrations of 32 elements and TOC (except for 

highway-berm vegetation), and selected SVOCs (except for 

catch-basin debris).

Sample Collection

Five samples of background soil were collected at a 

distance of about 100 ft from each of the principal and test 

highways in the vicinity of the monitoring stations, except 

for Interstate 190 where no samples were collected. Samples 

were collected at a distance of about 30 ft from Interstate 93 

in Boston because of the lack of available undeveloped land. 

Where possible, samples of soil were collected near trees 

with diameters greater than 1 ft because those trees were 

presumed to be in areas that were undisturbed for the last 

several decades. Samples were collected through successive 

soil horizons to a maximum depth of 1 ft with a stainless-steel 

soil-recovery probe equipped with a precleaned plastic liner. 

The plastic liners were cleaned by immersing the tubes in a 

5-percent solution of hydrochloric acid for a period of about 

6 hours and thoroughly rinsing them with deionized water 

until the specific conductance of the waste rinse water was less 

that 1 μS/cm.

Samples of surficial highway-berm soil were collected 

within 1 ft of the highway shoulder and at a depth of about 

0.1 ft at five locations along each principal highway in the 

vicinity of the monitoring stations. Samples were collected 

with an acid-washed polyethylene scoop and stored in clean 

polyethylene bags prior to shipment to the laboratory. Two 

samples of highway maintenance sand also were collected at 

each of the Massachusetts DOT maintenance depots servicing the principal highways because the materials are procured 

from different local sources at each depot. In contrast, because 

the salt used on all Massachusetts highways is from the same 

source, a single sample of maintenance salt (sodium chloride) 

and a single sample of liquid calcium chloride were collected 

from the Massachusetts DOT maintenance depot in Lexington, 

Massachusetts. The solid-matrix samples were collected with a 

stainless-steel soil-recovery probe equipped with a precleaned 

plastic liner. The sample of liquid calcium chloride was dispensed into an acid-cleaned bottle.

Two samples of highway-berm vegetation were collected along Interstate 495 after mowing operations. These 

samples mainly consisted of roadside grass and weeds. While 

berm vegetation was available near all the highways sites, it 

was most plentiful along Interstate 495 in the vicinity of the 

primary monitoring station. A sample of dry pine needles also 

was collected along Route 119 because the needles commonly 

accumulated on the road shoulder and were often found in 

composite samples of stormwater. Nine samples of catch-basin 

debris, consisting of particles greater than 250 micrometers, 

also were collected from a plankton net installed at the outfall 

of the primary station on Interstate 495.

Sample Processing

Samples of soil, highway-berm soil, and highway-maintenance materials were processed similarly. For soil samples, 

the soil from each core was separated from the organic-litter 

layer and homogenized. The organic litter composed of 

leaves and twigs was discarded. For highway-berm soils, the 

soil was homogenized, and the contents were inspected for 

nonhomologous materials (for example, plastic and foil wrappers) that could bias chemical analysis. Such materials were 

subsequently removed. Each homogenized sample of soil, 

highway-berm soil, or highway-maintenance sand was split 

into a minimum of two subsamples. One subsample was used 
Methods 27

to determine the particle-size distribution of the sample and 

the other subsample was analyzed for 32 inorganic elements. 

Samples of roadside vegetation, pine needles, and catch-basin 

debris were homogenized and reduced to fine particles with 

an electric chopper consisting of a stainless steel blade and an 

acrylic housing.

Sample Analysis

A particle-size gradation and an analysis for inorganic 

elements were performed for each sample of background soil, 

highway-berm soil, and highway-maintenance sand. Only 

an analysis for inorganic elements was performed on the 

samples of salt. Subsamples of soil, highway-berm soil, and 

highway-maintenance sand were evaluated for the percentage 

of particles less than 0.063 mm in diameter, from 0.063 mm to 

0.250 mm in diameter, and greater than or equal to 0.250 mm 

in diameter at the USGS Kentucky Water Science Center 

Sediment Laboratory. Samples of soil, highway-berm soil, 

highway-maintenance sand and salt, roadside vegetation and 

pine needles, and catch-basin debris were submitted to XRAL 

Laboratory for analysis of 32 inorganic elements. Samples 

were not milled prior to analysis. Concentrations of inorganic 

constituents in solid-matrix samples were determined with the 

use of USEPA method 3050B (U.S. Environmental Protection 

Agency, 1996) and ICP emission spectroscopy. The sample of 

liquid calcium chloride was submitted to the USGS NWQL in 

Denver, Colorado, for analysis of major ions, total nutrients, 

and selected total-recoverable metals. Samples of roadside 

vegetation and pine needles also were submitted to the USGS 

NWQL for analysis of PAHs. These compounds were determined by accelerated solvent extraction and gas chromatography (Zaugg and others, 2006b).

Estimation of Constituents Contributed to Runoff 

from Road Salt

The primary constituents of road salt, sodium (Na), 

calcium (Ca), and Cl, were measured directly in the composite 

samples of highway runoff but also were estimated from the 

more frequent in-situ measurements of specific conductance. 

The data set includes 129 EMCs for these dissolved ions, specific conductances of the composite samples ranging from 7 to 

62,500 μS/cm, and Cl concentrations ranging from less than 1 

to 22,600 mg/L. Specific conductance was measured instantaneously for 1,555 runoff events (rain, mixed precipitation, and 

snowmelt), and estimated event-mean in-situ measurements of 

specific conductance ranged from about 6 to 105,600 μS/cm. 

(Only four storms had specific conductance values greater than 

62,500 μS/cm.) Specific conductance measurements, which 

commonly are used to determine concentrations of dissolved 

major ions (Hem, 1982, 1992; Miller and others, 1988; Church 

and others, 1996; Granato and Smith, 1999), were used to estimate concentrations of dissolved Na, Ca, Cl, and sulfate (SO4

) 

in highway runoff to improve estimates of the populations of 

concentrations and loads of these constituents in runoff from 

Massachusetts highways.

Concentrations of dissolved Na, Ca, Cl, and SO4

 in highway runoff were estimated using the adjusted superposition 

technique (Granato and Smith, 1999) over the full range of 

flow-weighted in-situ measurements of specific conductance. 

The theoretical conductance for each major ionic species in 

solution is summed to calculate the superposition estimate. 

Specifically, the theoretical conductance of a solution is the 

product of each ion in milliequivalents per liter multiplied by 

the equivalent ionic conductance at infinite dilution (table 5). 

However, as the concentrations of dissolved constituents 

increase, superposition will increasingly overestimate the 

specific conductance measured in a water sample because 

of interactions among ions in high-ionic strength solutions 

(Harned and Owen, 1958; Smedley, 1980; Hem, 1982; Miller 

and others, 1988). The adjusted superposition technique is a 

semi-empirical method that improves the quantitative relations among estimated and measured specific conductance 

to account for the attenuating effects of the interactions in 

high-ionic strength solutions that cannot be adequately quantified using purely theoretical approaches (Granato and Smith, 

1999). In this study, nonparametric regression techniques 

(Granato, 2006) were used to develop an equation using the 

logarithms of the measured event-mean specific conductance 

(CM) and the logarithms of the specific conductance estimated 

by superposition (CC) for the 129 EMCs in the highway 

runoff data set to account for interionic effects on measured 

concentrations. This equation, retransformed from log space is

CC = 0.829 × CM 1.033757, (1)

where CC is the specific conductance (in microsiemens per 

centimeter) that would be calculated by superposition, and 

CM is the measured specific conductance (in microsiemens 

per centimeter). Equation 1 indicates that CM is slightly 

greater than CC at low concentrations (potentially because the 

contributions of some ions were not included in the calculation of the superposition values), and CM can be substantially 

less than CC for measured specific conductance values greater 

than about 5,000 μS/cm. The standard error of this estimate is 

0.126 percent, as calculated for all the regression models using 

the equation

  2

1

5.302 2

100 -1 MSE SE e

     ×  

 ×    , (2)

where SE is the standard error of estimate, in percent, 

and MSE is the mean square error in log (base 10) units 

(Driver and Tasker, 1990). The nonparametric coefficient of 

efficiency E (Legates and McCabe, 1999) also indicates the 

predictive power of a regression equation. The nonparametric 

coefficient of efficiency is
28 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 5. Theoretical conductance at infinite dilution, regression equation coefficients (equations 4 and 5), the standard error of the estimate, nonparametric coefficients of efficiency, and the median milliequivalent ratio to chloride for major ions in solution measured at highway sites in Massachusetts, 2005–07. [Cl, Choride; cm, centimeter; MEQ, milliequivalent; L, liter; μS microsiemens; mg/L, milligrams per liter; CC, calculated specific conductance (equation 1)] Major ion Theoretical conductance at infinite dilution (μS L/cm MEQ) Median milliequivalent ratio to chloride (MEQ/MEQ) Intercept of the regression equation, unitless (retransformed) Slope of the regression equation Standard error of the estimate (percent) Nonparametric coefficient of efficiency for ion ratios, unitless Nonparametric coefficient of efficiency for constituent concentrations, unitless Predicting Cl, in MEQ Predicting Cl, in mg/L Chloride 76.31 1 0.0038 1.081 1.26 0.943 0.967 Ratio of each ion to Cl, predicted from CC Ion (mg/L) Sodium1 50.08 1.07 1.394 -0.055 0.35 0.448 0.94 Sodium2 0.954 -0.007 Calcium 59.47 0.23 1.962 -0.449 23 0.305 0.300 Potassium 73.48 0.03 0.270 -0.487 18 0.274 0.556 Magnesium 53.00 0.06 0.198 -0.240 14 0.301 0.409 Sulfate 80.00 0.12 0.661 -0.350 18 0.253 0.529 Bicarbonate 44.5 0.22 14.02 -0.870 10 0.359 0.449

1Sodium-ratio estimates for specific conductance values less than 3,056 μS/cm.2Sodium-ratio estimates for specific conductance values greater than or equal to 3,056 μS/cm.
Methods 29

1

1

1

N

i i

i

N

i median

i

X Y

E

X Y





−

 −

−

∑

∑

, (3)

where Xi is the i

th measured value, Yi

 is the predicted value, N

is the number of measured values, and Xmedian is the median 

of the measured values. The nonparametric coefficient of 

efficiency E (Legates and McCabe, 1999) for the CM to CC

regression equation is 0.95, indicating that differences between 

regression estimates and estimates calculated from measured 

values are about 5 percent of the variability in CC estimates 

from measured values.

The specific conductance estimated by superposition 

(CC) from equation 1 may be used with estimates of the predominant ratios among major ions in solution and the theoretical conductance at equivalent dilution to estimate the concentration of Cl and other ions in solution. The concentrations of 

constituents in highway runoff should asymptotically converge toward the ratio of constituents in deicing materials as 

conductance increases because the deicing materials become 

the dominant source of these ions in solution (Granato, 1996). 

In eastern Massachusetts, ratios among major ions in highway runoff at low conductances also may approximate ratios 

of ions present in deicing materials because precipitation in 

the region is affected by coastal storms that are affected by 

entrainment of salt spray from the ocean by the storm system (Gay and Melching, 1995). For example for Na and Cl, 

maps with isopleths from the National Atmospheric Deposition Program (2008) indicate a substantial effect from coastal 

storms on precipitation quality for most of Massachusetts 

(excluding northwestern Massachusetts). Therefore, nonparametric regression techniques were used to develop equations 

to predict the ratio of each major ion to Cl (X/Cl) as a function 

of the specific conductance estimated by superposition (CC). 

These equations are in the form

log log   X b m CC

Cl

    ×     , (4)

where b is the intercept and m is the slope in logarithmic 

space, and

10 X b m CC

Cl  × , (5)

when retransformed. Regression coefficients for the equations 

used to calculate the ratio of Ca, magnesium (Mg), potassium 

(K), Na, bicarbonate (HCO3

), and SO4 to Cl from the specific 

conductance estimated by superposition (CC) are listed in 

table 5 with the standard error of the estimate calculated for 

all the ratios using equation 2 and the coefficients of efficiency 

calculated using equation 3.

The concentrations of Na, Ca, SO4

, and Cl are of particular interest for analysis of highway-runoff quality because they 

are the predominant constituents in highway deicing compounds. The regression equations developed to estimate the 

milliequivalent ratio of each constituent to Cl can be used to 

estimate the concentration of these major ions in solution. The 

equations used to derive EMC values for Na, Ca, SO4

, and Cl 

are as follows:

Na = Rna × Cl, (6)

Ca = Rca × Cl, (7)

SO4=Rso × Cl, (8)

and

Cl = CC ÷ ((Rna × Cna) + (Rca × Cca) +

(Rso × Cso) + (Rk × Ck) + (Rmg × Cmg) +

(Ralk × Calk) + (1 × Ccl)), (9)

where

	 CC	 is specific conductance calculated by 

superposition, in microsiemens per 

centimeter;

	 Ca is the milliequivalent concentration of 

calcium;

	 Na is the milliequivalent concentration of 

sodium;

	 Cl is the milliequivalent concentration of 

chloride;

	 SO4 is the milliequivalent concentration of sulfate;

	 Rna is the milliequivalent ratio of sodium to 

chloride;

	 Rca is the milliequivalent ratio of calcium to 

chloride;

	 Rso is the milliequivalent ratio of sulfate to 

chloride;

	 Rk is the milliequivalent ratio of potassium to 

chloride;

	 Rmg is the milliequivalent ratio of magnesium to 

chloride;

	 Ralk is the milliequivalent ratio of carbonate to 

chloride;

	 Cna is the equivalent theoretical conductance at 

infinite dilution of sodium (table 5);

	 Cca is the equivalent theoretical conductance at 

infinite dilution of calcium (table 5);

	 Cso is the equivalent theoretical conductance at 

infinite dilution of sulfate (table 5);

	 Ck is the equivalent theoretical conductance at 

infinite dilution of potassium (table 5);

	 Cmg is the equivalent theoretical conductance at 

infinite dilution of magnesium (table 5);

	 Calk is the equivalent theoretical conductance at 

infinite dilution for carbonate (table 5); and

	 Ccl is the equivalent theoretical conductance at 

infinite dilution of chloride (table 5).
30 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

These equations provide reasonable estimates of the 

concentration of Na, Ca, SO4

, and Cl from flow-weighted 

event-mean conductance measurements. The coefficient of 

efficiency of the modified superposition estimates for Na, Ca, 

SO4

, and Cl are about 0.94, 0.30, 0.53, and 0.97, respectively. 

These results indicate that the concentrations predicted using 

adjusted superposition are slightly better than the results of 

regression equations between measured conductance and constituent concentrations (table 6).

Data Quality

The accuracy and precision of the data collected in this 

study were ensured by making quality-control measurements 

at each of the monitoring stations, operating redundant sensors, collecting various types of quality-control samples, and 

conducting quality-assurance experiments. Quality-control 

samples include source-solution blanks, field blanks, replicate 

samples, field-matrix spike samples, and replicate field-matrix 

spike samples. Quality-control experiments were performed to 

assess the collection and processing of water samples containing coarse particles greater than 0.250 mm in diameter. 

The identification of random error and systematic bias can be 

achieved through the collection and analysis of quality-control 

data. These analyses provided the basis for the interpretation 

of continuous measurements of specific conductance and rainfall, and sediment and chemical data collected in this study.

Continuous Measurements

Comparative measurements of water level, water 

temperature, air temperature, and specific conductance were 

routinely made manually during sampling preparation, sample 

collection, and routine site visits to ensure the accuracy of the 

measurements and collection of highway-runoff composite 

samples. Rain gages also were checked periodically for debris 

buildup that could plug the device. Manual measurements of 

water levels were made by measuring the distance between 

the water surface near the site’s sensor and some common 

reference point. Differences resulting from sensor drift were 

immediately corrected. The accuracy of water-temperature and 

air-temperature data was determined by comparing measurements made by the monitoring system with those made by an 

independent probe calibrated against a National Institute of 

Standards and Technology traceable thermometer. The accuracy of specific conductance data was obtained by ensuring 

that the sensor was clean and free from debris, by documenting the performance of the sensor before and after sensor 

maintenance, and by noting the response of the clean sensor 

after placing it in several standard solutions. In addition, a 

redundant rain gage and a redundant specific conductance 

sensor were installed at the test station on Interstate 190 to 

determine the potential variability in measurements of rainfall 

totals and calculated event-mean specific conductance values, 

respectively.

A comparison of measurements made during site visits 

at each of the highway-monitoring stations indicated that the 

continuous measurements were generally accurate and precise. 

The difference between comparative measurements of water 

level was often less than about 0.02 ft, which was within the 

combined uncertainty of the measurements of the sensor and 

the manual comparative measurements. The median errors for 

raw measurements of specific conductance, which were the 

combined errors of fouling and drift measurements, ranged 

from about 5 to 21 percent prior to any improvements made on 

the basis of field calibration values. Non-winter rainfall totals 

measured concurrently by the primary and redundant tippingbucket gages at the monitoring station on Interstate 190 also 

were precise. About 80 percent of the redundant rainfall totals 

were within 0.01 in. of the primary measurements, and about 

95 percent of the redundant rainfall totals were with 0.04 in. of 

the primary measurements. The maximum difference between 

measurements from the two rain gages was 0.10 in. Larger differences between the amounts of rain measured by each gage 

could be the result of the physical mounting location of each 

gage and the direction and speed of wind during the storms.

Event-mean values of specific conductance for each runoff event were calculated on the basis of available continuous 

records of flow greater than 0.009 ft3

/s and records of in situ 

specific conductance; results were compared to the respective 

event-mean specific conductance of flow-weighted composite 

samples. These comparisons were done, in part, to determine 

whether the frequency of sample collection within storms was 

sufficient to accurately characterize the variability of dissolved 

Table 6. Regression equation coefficients and nonparametric coefficients of efficiency for measured specific conductance 

to concentrations for sodium, calcium, chloride, and sulfate measured in composite samples of highway runoff for 12 sites in 

Massachusetts, 2005–07.

Major ion

Intercept of the

regression equation,

unitless (retransformed)

Slope of the

regression equation

Nonparametric coefficient of

efficiency for constituent

concentrations, unitless

Chloride 0.111 1.117 0.939

Sodium 0.100 1.071 0.959

Calcium 0.144 0.677 0.263

Sulfate 0.138 0.772 0.509
Data Quality 31

solids and other constituents in runoff. This also was done to 

determine whether flows calculated from the stage-discharge 

relation for each monitoring station were reasonable.

Event-mean values for specific conductance also were 

calculated using data from the redundant sensor at the 

monitoring station on Interstate 190. The median difference 

between estimated event-mean values of specific conductance 

calculated independently from primary and redundant sensor 

data at the monitoring station on Interstate 190 is about 6 percent. The interquartile range for the respective differences is 

about 18 percent; differences vary from 2 to 20 percent. Larger 

differences between data from the primary and redundant sensors generally are the result of the redundant sensor not being 

adequately submersed because it was mounted slightly higher 

than the primary sensor.

The agreement between event-mean specific conductance, which was estimated from continuous records of flow 

and in situ measurements of specific conductance, and specific 

conductance measured in composite samples tended to have 

a low bias but generally was reasonable (fig. 13A) despite the 

sometimes large dissimilarity in runoff coefficients for storms 

during which the samples of highway runoff were collected. 

The median difference between estimated event-mean values 

of specific conductance and respective manual measurements 

of specific conductance in the same flow-weighted composite 

samples of highway runoff was about 10 percent for values 

less than 1,000 μS/cm (fig. 13B). For values of specific conductance greater than 1,000 μS/cm (fig. 13B), the respective 

difference was about 24 percent. The accuracy of most values 

of estimated event-mean specific conductance was within the 

precision of the comparative field measurements (5 to 21 percent) and the precision of the estimates made by the redundant 

sensor at the monitoring station on Interstate 190 (median 

difference of 6 percent). However, the accuracy of estimated 

values of event-mean specific conductance greater than 

1,000 μS/cm was often less, in part, because the sensors were 

typically calibrated to a 1,000 μS/cm standard, and as a result, 

the sensor generally was less accurate at values substantially 

greater than this value.

Chemical Quality of Water Samples

Quality-control samples of spiked sample water and 

blank water were collected to identify potential bias in sampling and processing methods and to identify contamination 

resulting from the sampling equipment and from the samplecollection, sample-processing, and sample-analysis methods. 

Other quality-control samples were collected in the field and 

laboratory to estimate analyte degradation, evaluate method 

recovery and performance, and determine the presence of 

interfering agents.

Field Quality-Control Samples

Quality-control samples collected in the Massachusetts 

Water Science Center laboratory and in the field include 

source-solution blanks, field blanks, replicate samples, fieldmatrix spike samples, and replicate field-matrix spike samples.

Field-Blank Samples

A field blank is used to test for positive bias that can 

result from contamination at any stage of sample collection, 

processing, or analysis, as well as from the sampling equipment itself. Source-solution blanks were prepared from deionized water produced by a laboratory-grade water-purification 

system that uses ion-exchange packs and reverse osmosis. The 

source-solution water was stored in Teflon-lined bottles until it 

was used as blank water for the collection of field blanks. The 

source-solution water was submitted for analysis of all constituents measured in this study at the time of bottling. Field 

blanks were collected throughout the study period and at every 

monitoring station. Field blanks were collected by the automatic sampler during preparation for storm sampling. These 

samples were collected by pumping blank water through the 

automatic sampler tubing and into the collection bottle, then 

processing it in a manner consistent with the collection of 

environmental samples of stormwater. The number of field 

blanks collected at each site was proportionate with the total 

number of samples collected at the site.

Over the course of the study period, 18 field blanks were 

collected and submitted for chemical and sediment analysis. A 

single bottle to be analyzed for PAHs and phthalates unfortunately was destroyed during shipment to the NWQL, and 

therefore, only 17 samples were analyzed for most of these 

analytes. Three field blanks also were collected and analyzed 

for concentrations of other less frequently measured anthropogenic and natural organic compounds. These samples provided 

replicate measurements for concentrations of several PAH and 

phthalate compounds. Measurable concentrations of each constituent in field-blank samples were compared to the long-term 

method detection limit (LTMDL). The LTMDL is the lowest 

detectable concentration of an analyte that can be measured 

and reported with 99 percent confidence that the concentration 

is greater than zero. The chance of falsely reporting a concentration at or greater than the LTMDL for a sample that does 

not contain the analyte is predicted to be less than or equal to 1 

percent (Childress and others, 1999). For analytes not detected 

in samples, a concentration equal to twice the LTMDL value 

(laboratory reporting limit) is reported with a “less than” (<) 

remark code in all data tables in this report.

A nonparametric statistical method, which focuses on 

the ranks of concentrations as opposed to the concentrations 

themselves, was used to determine whether the potential 

contamination observed in field-blank samples affected the 

utility of the data. This statistical technique is described in 

detail by Mueller (1998). In this study, the confidence level 

for the one-sided upper contamination limit was estimated 
32 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 13. Relation of (A) flow-weighted specific conductance values estimated from continuous records of flow and 

specific conductance to measured event-mean specific conductance of composite samples of highway runoff collected at 

12 monitoring stations on 8 highways for paired events, and (B) relative error between event-mean specific conductance 

and estimated values of event-mean specific conductance in three ranges.

1

10 100 less than 100 100 to 1,000 greater than 1,000

10

100

1,000

10,000

100,000

ESTIMATED EVENT-MEAN SPECIFIC CONDUCTANCE OF SAMPLES 

OF HIGHWAY RUNOFF, IN MICROSIEMENS PER CENTIMETER

MEASURED EVENT-MEAN SPECIFIC CONDUCTANCE OF COMPOSITE SAMPLES 

OF HIGHWAY RUNOFF, IN MICROSIEMENS PER CENTIMETER

1 1,000 10,000 100,000

-100

-50

0

50

100

RELATIVE ERROR, IN PERCENT 

 RANGE OF ESTIMATED EVENT-MEAN SPECIFIC 

 CONDUCTANCE IN MICROSIEMENS PER CENTIMETER 

 1:1 LINE

Maximum

90th percentile

75th percentile

Median

25th percentile

10th percentile

Minumum

EXPLANATION

A B
Data Quality 33

for the 90th percentile of highway-runoff concentration data 

on the basis of the number of field-blank samples and the 

measured concentration of each constituent in field blank 

samples in the highest rank. The maximum potential contamination bias for at least 90 percent of all samples was estimated 

(at various levels of confidence; table 7) to be less than the 

LTMDL for most of the constituents, except for Ca, total N, P, 

total-recoverable iron (Fe) and manganese (Mn), anthracene, 

benzo[a]pyrene, bis(2-ethylhexyl) phthalate, diethyl phthalate, 

di-n-butyl phthalate, indeno[1,2,3-cd]pyrene, naphthalene, 

and suspended sediment. The detection of a constituent at a 

concentration greater than or equal to the LTMDL was rare, 

limited to three or fewer observations, and the concentrations 

were often small in comparison to those measured in composite samples of highway runoff.

Low levels of contamination may be acceptable if the 

level of contamination is within the measurement error of 

the analytical method or is well below the concentrations of 

the constituent in the environmental samples. For example, 

the maximum concentration for Ca in the field blanks was an 

order of magnitude lower than the minimum concentration 

measured in composite samples of highway runoff. However, for other constituents, such as N, P, Fe, Mn, anthracene, 

benzo[a]pyrene, bis(2-ethylhexyl) phthalate, diethyl phthalate, 

di-n-butyl phthalate, indeno[1,2,3-cd]pyrene, naphthalene, 

and suspended sediment, concentrations in several samples 

of highway runoff were at or near the LTMDL and similar 

to the maximum observed concentrations in the field blanks. 

These cases were generally rare and 90 percent or more of 

the concentrations of N, Fe, Mn, and suspended sediment in 

samples of highway runoff were at least one order of magnitude greater than the maximum concentration measured in 

field blanks. Concentrations of Mn and suspended sediment 

also were detected in the source water in comparable concentrations, indicating that the water source, analytical containers, or laboratory processes during analysis could have been 

the source of contaminants. Concentrations of P, anthracene, 

benzo[a]pyrene, bis(2-ethylhexyl) phthalate, diethyl phthalate, 

di-n-butyl phthalate, indeno[1,2,3-cd]pyrene, and naphthalene 

in samples of highway runoff, on the other hand, were generally low, and therefore, the contamination bias is potentially 

greater. The median P concentration for all samples of highway runoff in this study was 0.10 mg/L. The precision of the 

analytical method is about ±0.004 mg/L at this concentration, 

and the method precision decreases to ±0.03 mg/L for higher 

concentrations (Patton and Kryskalla, 2003). Anthracene and 

naphthalene were detected in a single blank and exceeded 

only the lower LTMDL for the secondary analytical method. 

Benzo[a]pyrene, bis(2-ethylhexyl) phthalate, diethyl phthalate, 

di-n-butyl phthalate, and indeno[1,2,3-cd]pyrene also were 

infrequently detected in field blanks (table 7); however, the 

maximum potential contamination estimated for 90 percent of 

the field data is similar in magnitude to the median concentrations of individual constituents in all composite samples of 

highway runoff (0.14 to 5.02 μg/L). Furthermore, most of the 

higher concentrations of these constituents, defined by the 95th

percentile (0.9 to 18 μg/L), is less than one order of magnitude greater than the respective median concentration in the 

highway samples. Thus, the maximum contamination level for 

90 percent of these data can potentially account for a substantial amount of the concentration in most samples. Therefore, 

data for benzo[a]pyrene, bis(2-ethylhexyl) phthalate, diethyl 

phthalate, di-n-butyl phthalate, and indeno[1,2,3-cd]pyrene are 

to be viewed with caution because the magnitude of potential 

contamination measured in field blank samples, although rare, 

is similar to the concentration of each constituent measured in 

samples of highway runoff.

Contamination bias appeared to be random for all constituents except for naphthalene. Concentrations of naphthalene in field blanks often were equivalent to the concentrations measured in samples of highway runoff. Naphthalene 

was not detected in the four samples of source water used for 

field-blank samples; however, these analyses were performed 

at the time the water was bottled. Analysis of the field-blank 

concentrations with respect to the holding time of the source 

water indicates an increasing exponential trend with increased 

age of the source water. Naphthalene was detected in field 

blanks where the source water was at least 5 months old, and 

the concentrations of naphthalene increased with the age of 

the source water. 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, it is possible that the naphthalene leached 

from the bag over time. Considering this, it is unlikely that 

there is any measurable contamination bias for naphthalene in 

samples of highway runoff.

Replicate Samples

Replicate samples are samples that are thought to be 

identical in composition to the environmental samples. Replicate samples provide a measure of bias and variability in the 

method of sample collection, sample processing (splitting, 

filtering, and preservation), and laboratory analysis, and in 

sample changes, such as analyte degradation, that can occur 

prior to laboratory analysis.

In this study, replicate samples generally were not collected, but analyses were conducted for seven SVOCs using 

different analytical methods on sample splits of flow-weighted 

composite samples of highway runoff that provide the same 

kind of information provided by replicate quality-control 

samples. Replicate samples were split sequentially from 14 

composite samples of highway runoff and analyzed for concentrations of anthracene, benzo[a]pyrene, bis(2-ethylhexyl) 

phthalate, fluoranthene, phenanthrene, pyrene, and naphthalene by two different analytical methods. Most of the data 

on constituents were determined by an analytical method 

using methylene chloride extraction and gas chromatograph/

mass spectrometry analysis (Fishman, 1993). The secondary method, which provided measurements for 69 anthropogenic and natural organic compounds, including the seven 
34 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 7. Summary for contamination bias expected in 10 percent of samples of highway runoff collected in Massachusetts, 2005–07.—Continued [mg/L, milligrams per liter; μg/L, micrograms per liter; <, concentration is less than value shown; ND, not detected; E, the recovery or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; LTMDL, long-term method detection level; values in parentheses were determined by solid-phase extraction and capillary-column gas chromatography/mass spectrometry] Constituent Number of field blanks LTMDL Maximum concentration detected in field blanks Number of detects greater than or equal to the LTMDL reporting limit Maximum concentration measured in blank water Confidence that the maximum concentration is the upper limit for the 90 percentile of contamination Calcium, filtered, mg/L 18 0.01 E0.02 3 E0.005 85 Magnesium, filtered, mg/L 18 0.007 ND 0 ND 85 Potassium, filtered, mg/L 18 0.08 ND 0 ND 85 Sodium, filtered, mg/L 18 0.1 ND 0 ND 85 Alkalinity, filtered, laboratory, mg/L as calcium carbonate 18 5 ND 0 ND 85 Chloride, filtered, mg/L 18 0.1 ND 0 ND 85 Sulfate, filtered, mg/L 18 0.09 ND 0 ND 85 Total nitrogen (nitrate + nitrite + ammonia + organic-N), unfiltered, mg/L 18 0.03 E0.04 3 ND 85 Phosphorus, unfiltered, mg/L 18 0.01 E0.01 1 ND 85 Cadmium, unfiltered, μg/L 18 0.02 ND 0 ND 85 Chromium, unfiltered, μg/L 18 0.3 0.2 0 ND 85 Copper, unfiltered, μg/L 18 0.6 E0.38 0 ND 85 Iron, unfiltered, μg/L 18 3 E4 1 ND 85 Lead, unfiltered, μg/L 18 0.03 ND 0 E0.04 85 Manganese, unfiltered, μg/L 18 0.3 E0.2 0 E0.2 85

Nickel, unfiltered, μg/L 18 0.08 ND 0 E0.09 85

Zinc, unfiltered, μg/L 18 1 ND 0 ND 85

1-Methylnaphthalene, unfiltered, μg/L 3 0.03 E0.0066 0 ND 27

2,6-Dimethylnaphthalene, unfiltered, μg/L 3 0.05 ND 0 ND 27

2-Methylnaphthalene, unfiltered, μg/L 3 0.03 E0.0103 0 ND 27

3,4-Dichlorophenyl isocyanate, unfiltered, μg/L 3 0.06 ND 0 ND 27

3beta-Coprostanol, unfiltered, μg/L 2 0.38 ND 0 ND 19

3-Methyl-1H-indole, unfiltered, μg/L 3 0.07 ND 0 ND 27

3-tert-Butyl-4-hydroxyanisole, unfiltered, μg/L 3 0.16 ND 0 ND 27

4-Cumylphenol, unfiltered, μg/L 3 0.13 ND 0 ND 27
Data Quality

35

Table 7. Summary for contamination bias expected in 10 percent of samples of highway runoff collected in Massachusetts, 2005–07.—Continued[mg/L, milligrams per liter; μg/L, micrograms per liter; <, concentration is less than value shown; ND, not detected; E, the recovery or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; LTMDL, long-term method detection level; values in parentheses were determined by solid-phase extraction and capillary-column gas chromatography/mass spectrometry]

Constituent Number of field blanks LTMDL

Maximum

concentration 

detected in

field blanks

Number of 

detects greater 

than or equal 

to the LTMDL 

reporting limit

Maximum 

concentration 

measured in 

blank water

Confidence that 

the maximum

concentration is 

the upper limit 

for the

90 percentile

of contamination

4-n-Octylphenol, unfiltered, μg/L 3 0.11 ND 0 ND 27

4-Nonylphenol, unfiltered, μg/L 3 1.2 ND 0 ND 27

4-tert-Octylphenol, unfiltered, μg/L 3 0.11 ND 0 ND 27

5-Methyl-1H-benzotriazole, unfiltered, μg/L 3 0.35 ND 0 ND 27

9H-Fluorene, unfiltered, μg/L 17 0.17 ND 0 ND 83

Acenaphthene, unfiltered, μg/L 17 0.14 ND 0 ND 83

Acenaphthylene, unfiltered, μg/L 17 0.15 ND 0 ND 83

Acetophenone, unfiltered, μg/L 3 0.07 ND 0 ND 27

Acetyl hexamethyl tetrahydro naphthalene, unfiltered, μg/L 3 0.11 ND 0 ND 27

Anthracene, unfiltered, μg/L 20 0.19 (0.08) E0.009 (1) ND 88

9,10-Anthraquinone, unfiltered, μg/L 3 0.08 ND 0 ND 27

Atrazine, unfiltered, μg/L 3 0.08 ND 0 ND 27

BDE congener 47, unfiltered, μg/L 1 0.1 ND 0 ND 10

Benzo[a]anthracene, unfiltered, μg/L 17 0.13 E0.02 0 ND 83

Benzo[a]pyrene, unfiltered, μg/L 20 0.16 (0.06) E0.196 1 ND 88

Benzo[b]fluoranthene, unfiltered, μg/L 17 0.9 ND 0 ND 83

Benzo[ghi]perylene, unfiltered, μg/L 17 0.32 E0.127 0 ND 83

Benzo[k]fluoranthene, unfiltered, μg/L 17 0.23 E0.117 0 ND 83

Benzophenone, unfiltered, μg/L 3 0.1 E0.0544 0 ND 27

Benzyl n-butyl phthalate, unfiltered, μg/L (butylbenzyl phthalate) 17 0.63 ND 0 ND 83

beta-Sitosterol, unfiltered, μg/L 2 0.11 ND 0 ND 19

beta-Stigmastanol, unfiltered, μg/L 2 0.22 ND 0 ND 19

Bis(2-ethylhexyl) phthalate, unfiltered, μg/L 20 0.53 (0.85) E4.12 3 ND 88

Bisphenol A, unfiltered, μg/L 3 0.22 ND 0 ND 27

Bromacil, unfiltered, μg/L 3 0.1 ND 0 ND 27
36 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 7. Summary for contamination bias expected in 10 percent of samples of highway runoff collected in Massachusetts, 2005–07.—Continued [mg/L, milligrams per liter; μg/L, micrograms per liter; <, concentration is less than value shown; ND, not detected; E, the recovery or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; LTMDL, long-term method detection level; values in parentheses were determined by solid-phase extraction and capillary-column gas chromatography/mass spectrometry] Constituent Number of field blanks LTMDL Maximum concentration detected in field blanks Number of detects greater than or equal to the LTMDL reporting limit Maximum concentration measured in blank water Confidence that the maximum concentration is the upper limit for the 90 percentile of contamination Caffeine, unfiltered, μg/L 3 0.06 E0.0438 0 ND 27 Camphor, unfiltered, μg/L 3 0.09 ND 0 ND 27 Carbaryl, unfiltered, μg/L 3 0.13 ND 0 ND 27 Carbazole, unfiltered, μg/L 3 0.12 ND 0 ND 27 Chlorpyrifos, unfiltered, μg/L 3 0.12 ND 0 ND 27 Cholesterol, unfiltered, μg/L 2 0.3 ND 0 ND 19 Chrysene, unfiltered, μg/L 17 0.16 E0.03 0 ND 83 Cotinine, unfiltered, μg/L 3 0.29 ND 0 ND 27 N,N-diethyl-meta-toluamide (DEET), unfiltered, μg/L 3 0.12 ND 0 ND 27 Diazinon, unfiltered, μg/L 3 0.11 ND 0 ND 27 Dibenzo[a,h]anthracene, unfiltered, μg/L 17 0.35 E0.214 0 ND 83 Dichlorvos, unfiltered, μg/L 3 0.11 ND 0 ND 27 Diethoxynonylphenol (all isomers), unfiltered, μg/L (4-Nonylphenol diethoxylates) 3 1.2 ND 0 ND 27 Diethoxyoctylphenol, filtered, μg/L (4-tert-Octylphenol diethoxylate, aka OP2EO) 3 0.05 ND 0 ND 27 Diethyl phthalate, unfiltered, μg/L 20 0.31 (0.1) E0.453 1 ND 88

Dimethyl phthalate, unfiltered, μg/L 17 0.3 ND 0 ND 83

Di-n-butyl phthalate, unfiltered, μg/L 17 0.44 ND 2 ND 83

Di-n-octyl phthalate, unfiltered, μg/L 17 0.93 ND 0 ND 83

d-Limonene, unfiltered, μg/L 3 0.02 ND 0 ND 27

Fluoranthene, unfiltered, μg/L 20 0.15 (0.08) E0.05 0 ND 88

Hexahydrohexamethyl cyclopentabenzopyran (HHCB), unfiltered, μg/L 3 <.2 ND 0 ND 27

Indeno[1,2,3-cd]pyrene, unfiltered, μg/L 17 0.11 E0.164 1 ND 83

Indole, unfiltered, μg/L 3 0.08 ND 0 ND 27

Isoborneol, unfiltered, μg/L 2 0.05 ND 0 ND 19

Isophorone, unfiltered, μg/L 3 0.08 ND 0 ND 27
Data Quality

37

Table 7. Summary for contamination bias expected in 10 percent of samples of highway runoff collected in Massachusetts, 2005–07.—Continued[mg/L, milligrams per liter; μg/L, micrograms per liter; <, concentration is less than value shown; ND, not detected; E, the recovery or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; LTMDL, long-term method detection level; values in parentheses were determined by solid-phase extraction and capillary-column gas chromatography/mass spectrometry]

Constituent Number of field blanks LTMDL

Maximum

concentration 

detected in

field blanks

Number of 

detects greater 

than or equal 

to the LTMDL 

reporting limit

Maximum 

concentration 

measured in 

blank water

Confidence that 

the maximum

concentration is 

the upper limit 

for the

90 percentile

of contamination

Isoquinoline, unfiltered, μg/L 3 0.09 ND 0 ND 27

Menthol, unfiltered, μg/L 2 0.05 ND 0 ND 19

Metalaxyl, unfiltered, μg/L 3 0.13 ND 0 ND 27

Methyl salicylate, unfiltered, μg/L 3 0.07 ND 0 ND 27

Metolachlor, unfiltered, μg/L 3 0.12 ND 0 ND 27

Monoethoxynonylphenol (all isomers), unfiltered, μg/L 3 1.35 ND 0 ND 27

Monoethoxyoctylphenol, filtered, μg/L (4-tert-Octylphenol monoethoxylate, aka OP1EO) 3 0.5 ND 0 ND 27

Nitrobenzene, unfiltered, μg/L 17 0.11 ND 0 ND 83

p-Cresol, unfiltered, μg/L 3 0.08 ND 0 ND 27

Pentachlorophenol, unfiltered, μg/L 3 0.33 ND 0 ND 27

Phenanthrene, unfiltered, μg/L 20 0.16 (0.07) E0.02 0 ND 88

Phenol, unfiltered, μg/L 3 0.07 ND 0 ND 27

Prometon, unfiltered, μg/L 3 0.08 ND 0 ND 27

Pyrene, unfiltered, μg/L 20 0.18 (0.08) E0.04 0 ND 88

Tributyl phosphate, unfiltered, μg/L 3 0.11 ND 0 ND 27

Triclosan, unfiltered, μg/L 3 0.09 ND 0 ND 27

Triethyl citrate, unfiltered, μg/L 3 0.07 ND 0 ND 27

Triphenyl phosphate, unfiltered, μg/L 3 0.1 ND 0 ND 27

Tris(2-butoxyethyl) phosphate, unfiltered, μg/L 3 0.05 ND 0 ND 27

Tris(2-chloroethyl) phosphate, unfiltered, μg/L 3 0.08 E0.0411 0 ND 27

Tris(dichloroisopropyl) phosphate, unfiltered, μg/L 3 0.05 ND 0 ND 27

1,4-Dichlorobenzene, unfiltered, μg/L 3 0.03 ND 0 ND 27

Isopropylbenzene, unfiltered, μg/L 3 0.02 ND 0 ND 27

Naphthalene, unfiltered, μg/L 20 0.16 (0.03) E0.06 (1) ND 88

Tetrachloroethene, unfiltered, μg/L 3 0.22 ND 0 ND 27

Tribromomethane, unfiltered, μg/L (Bromoform) 3 0.03 ND 0 ND 27

Perylene, unfiltered, μg/L 17 0.2 ND 0 ND 83

Suspended sediment concentration, mg/L 18 1 1 1 1 85
38 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 8. Replicate sample statistics for seven organic compounds determined by methylene chloride extraction and gas 

chromatograph/mass spectrometry analysis and by continuous liquid-liquid extraction and capillary-column gas chromatography/

mass spectrometry analysis for 14 samples of highway runoff collected in Massachusetts, 2005–07.

Analyte Relative percent difference

Mean Standard deviation Minimum Maximum

Anthracene 30 29 3 94

Benzo[a]pyrene 12 5 5 22

Bis(2-ethylhexyl) phthalate 35 25 3 75

Fluoranthene 16 11 1 41

Phenanthrene 15 14 1 53

Pyrene 15 13 1 38

Naphthalene 14 14 1 34

compounds listed immediately above, used continuous 

liquid-liquid extraction and capillary-column gas chromatography/mass spectrometry analysis (Zaugg and others, 2006a). 

Replicate sample sets were evaluated by comparing the relative percent differences (RPDs) of the results for each pair of 

samples where the same analyte was detected in both samples. 

The average absolute RPD ranged from 12 to 16 percent for 

five of the seven compounds (table 8). The average RPDs 

for anthracene and bis(2-ethylhexyl) phthalate were 30 and 

35 percent (table 8), respectively. The standard deviation for 

the RPDs indicates the most precise values were determined 

for benzo[a]pyrene (standard deviation of about 5 percent) 

and the standard deviation for the other compounds (table 8) 

ranged from about 11 to 29 percent. The relative concentrations of the target analytes in the water samples did not seem 

to affect the variability of analyte recovery between samples 

processed using the different analytical methods.

Field-Spiked and Replicate Field-Spiked Samples

Field-spiked samples are quality-control samples in 

which known amounts of target compounds are added to 

environmental replicate-split samples, which are then measured. The degree of recovery for each target analyte added 

to the environmental sample is used to determine the bias and 

variability attributed to the amount of degradation of target 

analytes during holding and shipment to the laboratory, the 

analytical method, and interferences contained in the environmental sample that mask or enhance determinations of 

the target analytes, or matrix effects. Replicate field-spiked 

samples also were submitted to the NWQL for analysis. 

Similarly, known amounts of target compounds were added to 

replicate field-spiked samples. These samples were processed 

in the same manner as the field-spiked samples, such that the 

samples were expected to be essentially identical in composition. Comparing the recovery for an analyte in a replicate 

field-spiked sample to the recovery for an analyte in the paired 

field-spiked sample provides a measure of the variability 

attributed to the aforementioned processes that can affect the 

concentration of each analyte.

Field-spiked samples and replicate field-spiked samples 

were split sequentially from composites of water collected 

at most monitoring stations throughout the study period, so 

comparisons of different matrices and concentrations reveal 

storm-to-storm and seasonal variations in water chemistry. 

For two samples, the analytical detection level was raised for 

bis(2-ethylhexyl) phthalate by the NWQL to a value greater 

than the fortification amount, and as a result, recoveries for 

field-spiked samples could not be calculated. The analytical 

detection level also was raised for benzyl n-butyl phthalate, 

and a recovery for the field-spiked sample could not be 

calculated. The average recovery of each compound and the 

precision of the recoveries, determined on the basis of spiked 

replicate data, are presented table 9.

A single field-spiked sample and a single replicate fieldspiked sample also were collected and analyzed for the other 

anthropogenic and natural compounds that were sampled for 

less frequently. These data are presented in table 10. The average RPD between analyte recoveries in the field-spiked sample 

and analyte recoveries in the replicate field-spiked sample for 

all analytes was about 27 percent. Because only a single fieldspiked sample was collected, broad generalizations for the 

recovery of concentrations of organic compounds measured in 

the other 14 samples of highway runoff cannot be made with 

reasonable certainty.

Laboratory Quality Assurance and QualityControl Samples

In addition to the quality-control samples collected 

during this project, the NWQL routinely analyzes various quality-control samples, including laboratory reagent 

blanks, interference check solutions, laboratory-control 

samples, standard-reference materials, laboratory-reagent 

spiked samples, laboratory-preparation spiked samples, and 
Data Quality

39

Table 9. Recovery statistics for total-recoverable metals, polyaromatic hydrocarbons, and phthalate esters in laboratory-spiked preparation samples, field-spiked samples, and field-replicate-spiked samples and p values for Mann-Whitney tests between laboratory spiked preparation samples and field spiked samples for the study in Massachusetts, 2005–07.—Continued[NWQL, National Water Quality Laboratory; N, number of samples; CI, confidence interval; RPD, relative percent difference; %, percent; --, no data; NWQL preparation spike recoveries for organic compounds were provided in a written communication by the NWQL in 2007; NWQL preparation spike recoveries for inorganic constituents were obtained from the NWQL quality control data system in 2008 (http://nwqlqc.cr.usgs.gov/)]

Analyte

NWQL preparation

spike recoveries

(percent)

Field spike recoveries

(percent)

MannWhitney 

test

(95% CI)

Spike replicate recovery

(percent)

Average

Standard 

deviation N Average

Standard 

deviation Maxi- mum Mini- mum N p-value Average RPD Standard deviation for RPD N

Cadmium 98 2 152 -- -- -- -- -- -- -- -- --

Chromium 94 5 127 -- -- -- -- -- -- -- -- --

Copper 93 4 74 -- -- -- -- -- -- -- -- --

Iron 91 6 143 -- -- -- -- -- -- -- -- --

Lead 97 2 154 -- -- -- -- -- -- -- -- --

Manganese 96 3 153 -- -- -- -- -- -- -- -- --

Nickel 94 3 72 -- -- -- -- -- -- -- -- --

Zinc 93 4 79 -- -- -- -- -- -- -- -- --

Acenaphthene 77 15 64 80 16 101 52 8 0.661 12 14 7

Acenaphthylene 76 15 64 75 17 98 53 8 0.740 11 13 7

Anthracene 74 15 64 70 14 91 53 8 0.395 9 10 7

Benz[a]anthracene 78 14 64 73 11 85 58 8 0.490 9 8 7

Benzo[a]pyrene 70 15 64 65 13 83 48 8 0.375 8 8 7

Benzo[b]fluoranthene 77 15 64 80 26 122 43 8 0.661 12 10 7

Benzo[ghi]perylene 59 17 64 41 10 56 31 8 0.005 10 5 7

Benzo[k]fluoranthene 76 16 64 80 15 103 62 8 0.635 9 9 7

bis(2-Ethylhexyl) phthalate (DEHP) 100 89 61 38 55 111 0 6 0.064 36 30 5

Benzyl n-butyl phthalate (butylbenzyl phthalate) 102 23 64 118 28 163 93 7 0.140 16 17 6

Chrysene 78 14 64 74 18 103 48 8 0.525 10 7 7

Dibenz[a,h]anthracene 56 16 64 51 14 68 33 8 0.356 8 4 7
40 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 9. Recovery statistics for total-recoverable metals, polyaromatic hydrocarbons, and phthalate esters in laboratory-spiked preparation samples, field-spiked samples, and field-replicate-spiked samples and 

p values for Mann-Whitney tests between laboratory spiked preparation samples and field spiked samples for the study in Massachusetts, 

2005–07.—Continued[NWQL, National Water Quality Laboratory; N, number of samples; CI, confidence interval; RPD, relative percent difference; %, percent; --, no data; NWQL preparation spike recoveries for organic compounds were provided in a written communication by the NWQL in 2007; NWQL preparation spike recoveries for inorganic constituents were obtained from the NWQL quality control data system in 2008 (http://nwqlqc.cr.usgs.gov/)]

Analyte

NWQL preparation

spike recoveries

(percent)

Field spike recoveries

(percent)

MannWhitney 

test

(95% CI)

Spike replicate recovery

(percent)

Average

Standard 

deviation

N Average

Standard 

deviation Maxi- mum Mini- mum

N

p-value Average RPD Standard deviation for RPD

N

Diethyl phthalate (DEP) 99 21 64 90 31 126 30 8 0.687 17 13 7

Dimethyl phthalate 90 18 64 94 22 114 46 8 0.375 19 18 7

Di-n-butyl phthalate 98 19 64 75 26 108 38 8 0.015 9 10 7

Di-n-octyl phthalate 64 28 64 58 36 109 0 8 0.622 25 18 7

Fluoranthene 86 15 64 80 32 143 44 8 0.200 11 7 7

Fluorene 85 15 64 81 16 103 58 8 0.436 12 15 7

Indeno[1,2,3-cd]pyrene 61 15 64 47 13 64 35 8 0.031 9 5 7

Naphthalene 79 14 64 82 17 102 51 8 0.573 12 16 7

Nitrobenzene 87 15 64 92 18 110 55 8 0.200 15 16 7

Phenanthrene 79 14 64 82 26 136 50 8 0.837 10 11 7

Pyrene 85 16 64 77 28 132 44 8 0.160 9 7

Perylene 69 19 64 71 23 124 53 8 0.837 13 13 7
Data Quality 41

Table 10. Recovery statistics for selected natural and anthropogenic organic compounds in laboratory-spiked preparation samples, a 

single field-spiked sample, and a single replicate field-spiked sample for the study in Massachusetts, 2005–07.—Continued

[NWQL, National Water Quality Laboratory; RPD, relative percent difference; NWQL preparation spike recoveries for inorganic compounds were obtained 

from the NWQL QC Data system in 2008]

Analyte

NWQL preparation

spike recoveries

(percent)

Field spike

recovery

(percent)

Spike

replicate

RPD

Average (percent) Standard

deviation

1-Methylnaphthalene 66 17 72 24

2,6-Dimethylnaphthalene 63 17 68 19

2-Methylnaphthalene 64 17 71 22

3,4-Dichlorophenyl isocyanate 124 119 105 10

3beta-Coprostanol 74 24 208 6

3-Methyl-1(H)-indole (Skatole) 77 18 44 19

3-tert-Butyl-4-hydroxy anisole (BHA) 45 30 8 44

4-Cumylphenol 78 18 80 26

4-n-Octylphenol 74 18 69 14

4-Nonylphenol diethoxylate, (sum of all isomers) aka NP2EO 80 18 579 12

4-tert-Octylphenol 88 20 87 30

5-Methyl-1H-benzotriazole 74 21 464 13

Acetophenone 84 19 108 22

Acetyl hexamethyl tetrahydronaphthalene (AHTN) 79 17 64 13

Anthracene 73 16 63 16

Anthraquinone 79 17 82 26

Atrazine 81 20 45 36

Benzo[a]pyrene 69 17 47 24

Benzophenone 84 20 96 22

beta-Sitosterol 64 27 102 11

beta-Stigmastanol 61 27 156 11

bis(2-Ethylhexyl) phthalate 161 331 1 206

Bisphenol A 83 19 70 39

Bromacil 79 17 331 18

Caffeine 76 16 75 37

Camphor 77 17 86 34

Carbaryl 73 20 98 28

Carbazole 77 17 78 28

Chlorpyrifos 74 17 61 13

Cholesterol 69 22 163 16

Cotinine 48 17 185 42

N,N-diethyl-meta-toluamide (DEET) 88 20 108 26

Diazinon 77 20 48 30

Dichlorvos 77 19 101 26

para-Nonylphenol (total) (branched) 83 20 1,020 7
42 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 10. Recovery statistics for selected natural and anthropogenic organic compounds in laboratory-spiked preparation samples, a 

single field-spiked sample, and a single replicate field-spiked sample for the study in Massachusetts, 2005–07.—Continued

[NWQL, National Water Quality Laboratory; RPD, relative percent difference; NWQL preparation spike recoveries for inorganic compounds were obtained 

from the NWQL QC Data system in 2008]

Analyte

NWQL preparation

spike recoveries

(percent)

Field spike

recovery

(percent)

Spike

replicate

RPD

Average (percent) Standard

deviation

4-tert-Octylphenol diethoxylate, aka OP2EO 117 117 76 14

Diethyl phthalate 90 21 102 26

d-Limonene 29 15 61 22

Fluoranthene 78 17 60 22

Hexahydrohexamethyl cyclopentabenzopyran (HHCB) 80 17 58 11

Indole 78 18 26 16

Isoborneol 77 22 87 25

Isophorone 78 18 97 27

Isoquinoline 76 18 88 48

Menthol 85 29 84 34

Metalaxyl 83 18 89 35

Methyl salicylate 83 19 69 24

Metolachlor 80 16 80 21

4-Nonylphenol monoethoxylate, (sum of all isomers) aka NP1EO 83 18 557 18

4-tert-Octylphenol monoethoxylate, aka OP1EO 85 19 143 17

p-Cresol 78 18 77 45

Pentachlorophenol 65 25 330 38

Phenanthrene 74 16 65 23

Phenol 77 19 63 61

Prometon 79 18 86 33

Pyrene 74 19 61 24

Tributyl phosphate 89 23 84 7

Triclosan 83 18 102 25

Triethyl citrate (ethyl citrate) 82 20 97 30

Triphenyl phosphate 76 16 64 13

Tris(2-butoxyethyl)phosphate 82 23 95 18

Tris(2-chloroethyl)phosphate 79 17 80 26

Tris(dichlorisopropyl)phosphate 78 17 71 20

1,4-Dichlorobenzene 51 20 73 24

Isopropylbenzene 36 18 66 25

Naphthalene 69 18 81 23

Tetrachloroethylene 24 12 49 28

Bromoform 62 15 74 23
Data Quality 43

laboratory-duplicate samples to test and track method performance (Garbarino and others, 2006). The NWQL also adds 

surrogate compounds to all samples for determinations of 

SVOCs. Surrogate compounds, such as 2-fluorobiphenyl and 

p-terphenyl-d14, are expected to perform similarly to the compounds being analyzed for in the laboratory. Because these 

compounds are not normally found in the environment, the 

recovery of the surrogate compounds can be used to qualify 

the performance of the analysis.

Laboratory Spiked Samples

Laboratory-preparation spiked samples provide a 

measure of method performance because they are processed 

and analyzed in the same manner as environmental samples. 

Laboratory-preparation spiked samples are prepared by adding 

known concentrations of target analytes to blank water. Average field spike recoveries for PAH compounds were similar to 

the average laboratory-preparation spike recoveries (table 9), 

except for benzo[ghi]perylene and indeno[1,2,3-cd]pyrene, 

which were lower for field-spiked samples. Average spike 

recoveries for the study period for phthalate compounds 

also were similar to the average laboratory-preparation 

spike recoveries for the respective compounds, except for 

bis(2-ethylhexyl) phthalate and di-n-butyl phthalate (table 9), 

which were notably lower.

The Mann-Whitney test, also referred to as the rank-sum 

test, was used to determine whether the independent populations of field-spike values were statistically different than 

laboratory-preparation spike values to comprehend whether 

or not the sample collection and field processing potentially 

affected the concentration of the PAH and phthalates in the 

composite samples of highway runoff. The Mann-Whitney 

test is a nonparametric method that makes no assumptions 

about the distribution of data and is used to determine whether 

groups of data come from the same population or, alternatively, whether the median values are different (Helsel and 

Hirsch, 2002). Resultant p values are listed in table 9. These 

data indicate the populations of field-spike recoveries for 

benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and di-n-butyl 

phthalate are significantly different (p value less than 0.05) 

than the populations of laboratory-preparation spike recoveries 

for the respective compounds. The result for bis(2-ethylhexyl) 

phthalate is significant at a slightly higher confidence interval (table 9). Because the variability of field-spike recoveries for these compounds was similar to the variability of 

laboratory-preparation spike recoveries, and because the 

replicate field-spike recoveries for these compounds indicate 

that the measurements are relatively precise, such differences 

are likely attributable to the degradation of the compounds 

prior to laboratory processing or potential matrix effects that 

masked the compounds. As a result, these data indicate that 

concentrations of benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, 

and di-n-butyl phthalate are likely underestimated in samples 

of highway runoff collected in this study. The recoveries for 

other analytes that were fortified in samples of highway runoff 

were similar to the recoveries of the same analytes in laboratory-preparation spike samples, which were prepared from 

organic-free blank water.

For the less frequently measured natural and anthropogenic compounds (table 4), about 57 and about 84 percent 

of the spike recoveries in the single composite sample of 

highway runoff were within one and three standard deviations, 

respectively, of the average recoveries for the same analytes 

in laboratory-preparation spiked samples analyzed during the 

sampling period. Field-spike recoveries of 3beta-coprostanol, 

4-nonylphenol diethoxylate, beta-stigmastanol, bromacil, 

cholesterol, cotinine, para-nonylphenol, 4-nonylphenol 

monoethoxylate, 4-tert-octylphenol monoethoxylate, and 

pentachlorophenol, which were greater than three standard 

deviations from the average recoveries for the same analytes 

in laboratory-preparation spiked samples, ranged from 142 

to 1,020 percent. Except for the aforementioned compounds, 

the field and laboratory spike recoveries are similar for this 

sample of highway runoff (table 10).

Field-spiked samples for major ions and total-recoverable 

metals were not collected during this study because these 

constituents do not readily degrade during the short holding 

periods prior to shipment to the laboratory. However, laboratory-preparation spike recoveries were routinely performed 

for total-recoverable metals to monitor potential losses 

during sample digestion. These data indicate that the average recovery for fortified concentrations of total-recoverable 

metals in laboratory-preparation spiked samples was relatively 

accurate and precise. Average recoveries for total-recoverable 

metals processed by the in-bottle digestion method (Garbarino and Hoffman, 1999) ranged from 91 to 98 percent during 

this study (table 9).

Surrogate-Compound Recovery

Surrogate-compound recoveries provide a measure of 

method performance for each individual sample. The recoveries of all surrogate compounds are used to evaluate process 

control of the analytical method. Thus, if the recovery of 

only one surrogate is outside of acceptable control limits, the 

sample measurements typically are considered valid. When 

surrogate recoveries are outside acceptable control limits 

(usually low) as a result of an identified process failure, the 

results for the associated analytes are usually flagged by the 

NWQL as estimated values; if the recovery of the surrogate 

compounds is poor, the results are deleted. Reporting levels 

are adjusted upward under some circumstances.

The surrogate compounds 2-fluorobiphenyl and 

p-terphenyl-d14 were routinely added to samples during the 

sample preparation at the NWQL for the analysis PAHs and 

phthalates. The median recovery of these surrogate compounds for all composite samples of highway runoff was 

about 71 and 52 percent, respectively. Surrogate recoveries of 

2-fluorobiphenyl and p-terphenyl-d14 for about 19 percent and 

about 12 percent of the samples, respectively, were outside 

of laboratory control limits of 38 to 90 percent and 27 to 
44 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

102 percent, respectively (Duane Wydoski, written commun. 

2008). For nine composite samples of highway runoff (about 

7 percent of all composite samples analyzed using the primary 

method), the recovery of both surrogate compounds was outside of control limits. The surrogate compounds caffeine-13C, 

fluoranthene-d10, bisphenol A-d3, and decafluorobiphenyl 

were added to samples during the sample preparation at the 

NWQL for the analysis of other natural and anthropogenic 

organic compounds. With the exception of a recovery for 

bisphenol A-d3 in a single sample of highway runoff, recoveries for all surrogate compounds in samples of highway runoff 

were within acceptable laboratory control limits.

Laboratory-Blind Samples

The USGS Office of Water Quality Branch of Quality Systems also submits various quality-control samples to 

ensure that data produced by USGS laboratories, including 

sediment laboratories, are of a known quality and are sufficient to provide long-term comparability and consistency 

on a national basis (U.S. Geological Survey, 2008a). Two 

single-blind sediment-laboratory quality assurance tests were 

conducted during each year of this study. Single-blind samples 

were samples of known concentrations and particle-size distribution values that were submitted to the sediment laboratory 

for analysis and identified as quality-control samples. Laboratory results were compared to the known values to measure the 

bias and variance of suspended-sediment data.

Analyses of laboratory blind samples indicate that the 

measurements of concentrations of suspended sediment in 

water samples collected during this study are accurate and 

precise. The median absolute difference between known 

concentrations of sediment in laboratory blind samples and 

concentrations of suspended sediment reported by the Kentucky Water-Science Center Sediment Laboratory was less 

than 1 percent for the study period (U.S. Geological Survey, 

2008b). Concentrations of suspended sediment in laboratory blind samples ranged from 134 to 10,333 mg/L in these 

samples. The absolute median differences for concentrations 

of suspended sediment less than 0.063 mm in diameter and 

greater than or equal to 0.063 mm in diameter were within 

about 2.8 and 7.7 percent, respectively (U.S. Geological Survey, 2008c, 2008d). Concentrations of sediment greater than 

or equal to 0.063 mm in diameter had higher variability than 

the concentrations of the total sediment mass and the fine sediment fraction. This is likely because finer material (composed 

of silts and clays) has a tendency to conglomerate. As a result, 

the determination of fines is generally biased low, whereas 

determinations of sands are biased high as a result of the conglomeration of fines. The percent error decreases for samples 

with high concentrations because the percent errors are exaggerated for analyses of samples with low-concentrations. Loss 

or reduction in diameter of a few grains of sand-size material 

during sample processing also can cause errors. About 5 to 

15 percent of the sample sediment mass in the laboratory-blind 

samples was composed of sand-size material, and error may, 

to some degree, be exaggerated for determinations of these 

low quantities.

Sampling Methods, Chemical Quality, and 

Particle Size for Suspended Sediment and Soil 

Samples

Effectiveness of Sampling Methods for 

Suspended Sediment

Three quality-control experiments were performed to 

assess the accuracy and bias of automatic-sample collection 

and manual-processing methods that could affect the distribution of sediment particle size in water samples. The concentration and size distribution of sediment can vary widely 

in samples of highway runoff. Most of the coarse-grained 

material in samples of bottom material collected from oilgrit separators on Interstate 93 that receive flow from catch 

basins (Smith, 2002) ranged from fine sand to gravel less than 

about 6 mm in diameter. Quality-assurance data from recent 

studies indicate that samples of water containing clay- and 

silt-size particles can be collected with automatic samplers and 

processed with standard splitting techniques with reasonable 

precision (Breault and others, 2005; Smith, 2002); however, 

it is more difficult to collect and split representative samples 

of water containing large concentrations of sand-size particles 

(Selbig and others, 2007).

Automated Collection of Samples of Suspended 

Sediment, Controlled Experiment

Automatic sampling is a convenient, cost-effective, 

and systematic method for collecting samples of water that 

represent the mean quality of stormwater, which would be 

impractical if performed manually. Nevertheless, all sampling, 

as well as sample-processing techniques, are subject to bias. 

The automatic samplers used in this study were basically 

heavy-duty battery-powered peristaltic pumps under the control of the datalogger. Like most modern automatic samplers, 

these devices are capable of purging and rinsing the sample 

lines and dispensing relatively precise amounts of water to 

the sample-collection bottle (generally within about 5 percent 

of the programmed volume during calibration tests in the 

field). The sampler pumps operate at a fixed speed producing 

a constant intake velocity of about 2 ft/s and, therefore, are 

not capable of collecting isokinetic samples (a sample collected with the velocity of water at the intake of the collection 

device being the same as the velocity of water flowing past the 

device) under all circumstances. As a result, the distribution 

of the particle size in sediment in water samples collected by 

such devices can be affected by the hydraulic characteristics 

at the point within the pipe where the intake is located. For 

small diameter pipes, the sampler intakes are often mounted 

near the floor of the pipe to maximize the allowable range for 
Data Quality 45

the collection of samples. Consequently, this increases the risk 

of oversampling coarse particles because vertical gradients of 

sediment can form with the largest particles concentrating near 

the floor of the pipe (Bent and others, 2001). In contrast, under 

environmental conditions where the water velocity is greater 

than that of the intake velocity of the sampler, the momentum 

of coarse particles may preclude them from being entrapped 

by the currents at the sample intake (Edwards and Glysson, 

1999). To overcome such shortcomings, a static mixer was 

developed prior to the field study to reduce the bias associated 

with the collection of water samples by a pump with a fixed 

intake velocity over the expected range of field conditions. 

The static mixer (fig. 12) is a carefully designed baffle, which 

was mounted in a pipe, produced a hydraulic environment 

with reduced sediment-transport velocities and provided turbulence that enabled the collection of coarse-grained sediments 

over a wide range of flows. The design of the static mixer 

and the relative placement of the sampler intake were modified on a trial and error basis as a result of observations of the 

behavior of coarse-grain sediments over a range of flows in 

the test pipe (fig. 14) where the static mixer was mounted and 

by collection of samples of sediment-laden water. During this 

time, other tests were conducted with the automatic sampler, 

but without the static mixer. With the sampler intake oriented 

downstream and without a static mixer installed, the successful collection of samples of water by the automatic sampler 

decreased as velocity increased, and visual inspections of the 

contents of sample collected under high water-velocity conditions indicated that few coarse-grain particles were collected at 

higher velocities. Mixed results also were noted in tests where 

the static mixer was not used and the sampler intake was oriented upstream. Occasionally during these tests, the sampler 

intake was plugged by coarse sand- and small gravel-size 

particles, and the sampler could not successfully purge and 

dislodge the particles under high water-velocity conditions.

Previous studies indicate that fine-grained particles are 

evenly distributed throughout the water column (Smith, 2002; 

Butler and others, 1996). Therefore, the focus of the experiments in this study was to define the potential limitations of 

collecting representative samples of water containing a distribution of sediment particles ranging from about 0.250 mm 

to about 6 mm in diameter. During the first experiment, a test 

structure was designed to simulate flow and sampling conditions in a typical highway drainage pipe (fig. 14). Artificial 

flows containing low concentrations of suspended sediment 

(about 3–6 mg/L) were metered into one end of a test pipe, 

which was 12 in. in diameter by 20 ft in length. Flow in 

the test pipe was generated by as many as three 9,600-gal/h 

centrifugal pumps. Flow from each pump was measured by 

an industrial flow sensor. A dry mixture of sand and gravel 

with particle diameters as large as about 6 mm was metered 

by gravity into the flow stream about 4 ft downstream from 

the point where the flow entered the pipe. The sampler intake, 

which was fixed 0.1 ft upstream from the static mixer, was 

mounted about 4 ft from the outlet of the test pipe. Two sets 

of paired samples were collected at five different flow rates 

ranging from about 0.10 to 0.85 ft3

/s. One 850-mL sample 

of water was collected by the automatic sampler while a 

paired sample of sediment was collected concurrently during 

the forward-pumping cycle of the automatic sampler with a 

plankton net at the end of the pipe (fig. 14). The plankton net 

captured the entire mass of sediment greater than 0.250 mm in 

diameter during the sampling period of the automatic sampler. 

The distribution of particle sizes in samples of suspended 

sediment collected by the automatic sampler and samples of 

sediment collected from the plankton net were determined by 

wet-sieving methods.

Particle-size analysis of samples of water collected by an 

automatic sampler in conjunction with a static mixer indicate 

that samples of suspended sediment with particle sizes ranging from 0.250 mm to more than 4.0 mm can be consistently 

collected using this method over a range of flows (fig. 15). 

Results of the experiment indicate that fine-grain sands (0.250 

to 0.500 mm) were consistently undersampled by the automatic sampler. This systemic bias could have resulted from 

water-surface tension that prevented the powdered sediment, 

which was metered by gravity through the top of the pipe, 

from thoroughly mixing with the flowing water in the pipe. As 

a result, the difference in distributions of the coarser particles 

also appeared to be systemic. Because these data are expressed 

as a percentage of the total distribution, the bias in the larger 

size particles is likely the result of the forward propagation of 

the systemic bias observed in the 0.250- to 0.500-mm diameter range. Furthermore, although the samples of suspended 

sediment were collected concurrently with samples from the 

autosampler and with the plankton net, the physical segments 

of water that were sampled were not necessarily identical in 

concentration because the sampling locations were different; 

therefore, the concentrations of sediment for each particle-size 

fraction cannot be compared without error.

Automated Collection of Samples of Suspended 

Sediment, Field Experiment

The second experiment was conducted in the field at the 

primary station on Interstate 495. For this experiment, samples 

of stormwater for the evaluation of concentrations of suspended sediment were collected by an automatic sampler and 

static-mixer assembly concurrently with samples of total sediment greater than 0.250 mm in diameter collected by a plankton net fastened to the outlet of the drainage pipe (fig. 16). The 

automatic sampler was triggered to collect samples of highway 

runoff on a flow proportional basis consistent with the protocols used throughout the study; therefore, only a small fraction 

of water was collected compared to the amount that flowed 

through the plankton net. The concentration of suspended 

sediment greater than 0.250 mm in diameter in the water 

samples was determined by dividing the dry mass of sediment 

by the mass of the water (ASTM, 2002). In most cases, the 

water samples were not split for other analyses, and the entire 

sample was processed. Similarly, the concentration of suspended sediment greater than 0.250 mm in diameter collected 
46 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 14. Test pipe and sampling equipment (top) where the static mixer assembly was tested; (lower left) looking upstream; and 

(lower right) turbulence created by the static mixer at the sampler intake location. The plankton net, which was used to collect the 

total mass of sediment at the end of the test pipe during the experiment, is draped over the end of the pipe in the photograph.

Automatic 

sampler

Automatic 

sampler

Plankton net Plankton net Flow direction

Sampling

tube

Static

mixer
Data Quality 47

Figure 15. Sediment particles greater than 0.250 millimeters in diameter collected by an 

automatic sampler with the intake mounted to a static mixer over a range of artificial flows in 

relation to the percentage of the total mass of sediment particles greater than 0.250 millimeters in 

diameter collected at the end of the test pipe.

 PARTICLES BETWEEN 0.500 AND 1.00 MILLIMETER IN DIAMETER

0

5

10

15

20

25

30

35

 PARTICLES BETWEEN 0.250 AND 0.500 MILLIMETER IN DIAMETER

PERCENTAGE OF THE TOTAL MASS

0

5

10

15

20

25

30

35

PERCENTAGE OF THE TOTAL MASS

0

5

10

15

20

25 PARTICLES BETWEEN 1.00 AND 2.00 MILLIMETERS IN DIAMETER

PERCENTAGE OF THE TOTAL MASS

0

5

10

15

20

25 PARTICLES BETWEEN 2.00 AND 4.00 MILLIMETERS IN DIAMETER

PERCENTAGE OF THE TOTAL MASS

0

5

10

15

20 PARTICLES GREATER THAN 4.00 MILLIMETERS IN DIAMETER

PERCENTAGE OF THE TOTAL MASS

0.11 0.11 0.20 0.33 0.34 0.50 0.50 0.84 0.84

RATE OF FLOW, IN CUBIC FEET PER SECOND

0.19

EXPLANATION

Autosampler

Plankton net
48 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 16. Plankton net attached to the outfall of the primary highway-runoff monitoring site on Interstate 495, Boxborough, 

Massachusetts.
Data Quality 49

by the plankton net was determined by dividing the dry mass 

of sediment less than 6.0 mm by the volume of the water 

calculated for the entire storm. This experiment was conducted 

for 10 storms from January 2007 through October 2007.

Information from this test indicates that the concentrations of suspended sediment greater than 0.250 mm in 

diameter in flow-proportional composite samples of highway 

runoff were higher than the concentrations estimated for 

samples collected by a plankton net fixed to the end of the pipe 

(table 11). The average and relative standard deviation for the 

differences between paired samples were 187 and 56 percent, 

respectively. Considering that the amount of water collected 

by the automatic sampler for each storm was about 0.03 percent of the entire storm volume, the variability in the differences between the concentrations in the paired samples is not 

unreasonable. However, for samples of highway runoff collected by the automatic sampler, these data potentially indicate 

that there is a positive bias for the concentration of sediment 

particles greater than 0.250 mm in diameter. In contrast, the 

average TOC content in nine samples of material retained by 

the plankton net was about 20 percent and ranged as high as 

43 percent (table 12). The high TOC content in these samples 

is attributed to large amounts of natural organic material (grass 

and leave particles). Because these materials are less dense 

than mineral sediments, it also is possible that the automatic 

samplers collected these materials disproportionally. The lack 

of precision in sampling coarse sediments has only marginal 

effects on the concentrations of many constituents affiliated 

with suspended sediment because most metals and hydrophobic organic compounds tend to be concentrated on the particles less than 0.063 mm in diameter (Smith, 2005; Breault and 

others, 2005). Similarly, if the positive bias for the concentration of coarse sediment particles is explained by the disproportionate collection of natural organic particles, the effect on the 

concentrations of many constituents in the water samples may 

not be large; P is the exception because it is generally present 

in high concentrations in vegetation matter compared to the 

concentrations in soil and sediments. The difference between 

concentrations of suspended sediment greater than 0.250 mm 

in diameter collected by the automatic sampler and that collected by the plankton net can be explained by the previously 

stated reasons. Nevertheless, the quality-assurance data indicate that potentially there is a positive bias for concentrations 

of sediment particles greater than 0.250 mm in diameter, and 

there could be a bias for concentrations of P in some samples 

of highway runoff. Because water samples were collected in 

a nearly identical manner at all monitoring stations, it also 

is likely that this same bias may affect the concentrations of 

coarse sediments and P in water samples collected from other 

monitoring stations in this study as well.

Sample Splitting

One of the most often overlooked sources of bias in 

concentrations of sediment particles, as well as in concentrations of constituents affiliated with such sediments, results 

from splitting the water sample in the field or in the laboratory prior to analysis (Selbig and others, 2007). The analysis 

for concentrations of suspended sediment used in this study 

(ASTM, 2002) did not require that the water sample be split 

in the laboratory, in contrast to the total suspended solid 

method (American Public Health Association, American Water 

Table 11. Results of field tests of paired samples of suspended sediment greater than 0.250 millimeters in diameter in highway runoff 

collected by a plankton net and an automatic sampler used in conjunction with a static mixer for the total flow-weighted mass of

sediment collected at the end of a pipe at the primary station on Interstate 495, in Boxborough, Massachusetts, 2005–07.

[mm/dd/yyyy, month/day/year; in., inches; mm, millimeter; mg/L, milligrams per liter]

Storm Date

(mm/dd/yyyy)

Storm total

(in.)

Concentration of suspended sediment

greater than 0.250 mm in diameter Water sample

difference

(percent)

Estimated plankton

net sample

(mg/L)

Flow-weighted

composite sample 

(mg/L)

1 01/08/2008 0.88 0.9 2.8 301

2 05/02/2007 0.14 3.8 12 313

3 05/18/2007 1.56 5.3 1.4 26

4 07/11/2007 0.19 8.2 14 169

5 07/18/2007 0.23 1.9 2.1 113

6 08/06/2007 0.23 15 22 144

7 08/08/2007 0.51 18 19 105

8 09/10/2007 0.37 31 40 129

9 10/12/2007 0.74 5.6 20 351

10 10/20/2007 1.19 40 88 222
50 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 12. Concentrations of constituents measured in samples of solids with diameters ranging from 0.250 millimeter to 6.0 millimeters collected from a plankton net at the outfall of the primary station on Interstate 495 in Massachusetts, 2005–07. [mm/dd/yyyy, month/day/year; <, less than value shown; ppm, parts per million; %, parts per hundred; TOC, total organic carbon] Storm date (mm/dd/yyyy) Silver (ppm) Aluminum

%

Arsenic

(ppm)

Barium

(ppm)

Beryllium

(ppm)

Bismuth

(ppm)

Calcium

%

Cadmium

(ppm)

Cobalt

(ppm)

Chromium

(ppm)

Copper

(ppm)

Iron

%

1/8/2007 <0.2 0.62 7 320 <0.5 <5 0.71 1 6 361 184 2.9

3/2/2007 <0.2 0.37 8 155 <0.5 <5 0.68 <1 4 123 78.9 1.74

4/27/2007 <0.2 0.64 12 183 <0.5 <5 0.91 <1 5 136 69.2 2.49

5/2/2007 <0.2 0.64 7 212 <0.5 <5 0.98 <1 6 1,110 106 2.88

5/18/2007 <0.2 0.54 7 288 <0.5 <5 0.72 <1 6 214 111 1.79

7/11/2007 <0.2 0.43 7 291 <0.5 <5 0.94 <1 6 171 156 2.03

7/18/2007 0.4 0.36 3 291 <0.5 <5 0.87 2 5 439 179 1.53

8/6/2007 <0.2 0.55 6 313 <0.5 <5 1.02 4 9 120 182 2.37

8/8/2007 <0.2 0.52 6 340 <0.5 <5 0.9 <1 15 123 142 2.84

Storm date 

(mm/dd/yyyy)

Potassium

%

Lanthanum

(ppm)

Lithium

(ppm)

Magnesium

%

Manganese

(ppm)

Molybdenum

(ppm)

Sodium

%

Nickel

(ppm)

Phosphorus

%

Lead

(ppm)

Antimony

(ppm)

Scandium

(ppm)

1/8/2007 0.12 8.2 12 0.3 290 12 0.07 33 0.06 53 7 0.9

3/2/2007 0.09 6.5 9 0.24 188 6 0.05 17 0.02 32 <5 0.7

4/27/2007 0.13 8.6 13 0.41 260 6 0.05 22 0.04 24 <5 1.2

5/2/2007 0.16 11.5 11 0.36 318 12 0.09 32 0.06 24 <5 1.2

5/18/2007 0.13 6.5 10 0.3 211 10 0.05 23 0.04 44 <5 1

7/11/2007 0.11 8.6 15 0.25 255 30 0.07 31 0.11 75 <5 0.6

7/18/2007 0.09 4.3 27 0.19 236 16 0.08 34 0.25 42 <5 <0.5

8/6/2007 0.13 7.4 14 0.31 291 17 0.08 46 0.1 53 <5 1

8/8/2007 0.12 7.9 11 0.28 279 15 0.06 92 0.07 54 <5 0.9

Storm date 

(mm/dd/yyyy)

Tin

(ppm)

Strontium

(ppm)

Thallium

%

Vanadium

(ppm)

Tungsten

(ppm)

Yttrium

(ppm)

Zinc

(ppm)

Zirconium

(ppm)

TOC

%

1/8/2007 10 45.4 0.03 42 <10 3.9 1,310 3.2 19

3/2/2007 <10 38.9 0.03 23 <10 2.8 365 2.8 8.74

4/27/2007 <10 32.3 0.04 27 <10 4.2 386 4.7 9.53

5/2/2007 10 40.1 0.04 32 <10 4.2 488 3.4 13.2

5/18/2007 <10 33.2 0.03 25 <10 3.4 568 4.5 15.6

7/11/2007 10 48.8 0.02 23 <10 3 1370 2.4 32.8

7/18/2007 10 47.4 <0.01 20 <10 2.5 1370 1.7 43.2

8/6/2007 <10 45.7 0.03 24 <10 3.5 1700 3.5 20.7

8/8/2007 <10 41.3 0.03 22 <10 3.2 1520 5.8 19.9
Data Quality 51

Table 13. Means and relative standard deviations for 14 sequential replicate samples analyzed for concentrations of suspended 

sediment in an experiment to assess the precision of field-splitting methods used in this highway-runoff study in Massachusetts, 

2005–07.

[mm, millimeter; mg/L, milligrams per liter; <, less than]

Sediment-size

description

Range of

particle diameters

(mm)

True concentration of 

sediment-water mixture

(mg/L)

Mean concentration

of sediment in

subsamples

(mg/L)

Relative standard

deviation for

concentrations of

sediment in

subsamples

(percent)

Clay and silt < 0.063 mm 158 158 2.4

Very fine to fine sand 0.063 < 0.250 mm 308 316 32.9

Median to coarse sand 0.250 < 1.0 mm 503 523 61.6

Very coarse sand 1.0 < 2.0 mm 456 475 77.6

Very-fine sand to coarse sand 0.063 < 2.0 mm 1,267 1,314 58.8

Works Association, and Water Pollution Control Federation, 

1995). Furthermore, an in-bottle digestion method (Garbarino 

and Hoffman, 1999) was used to partially digest unfiltered 

samples of water prior to analysis for total-recoverable metals 

at the NWQL. These methods eliminate any potential bias 

associated with splitting samples containing large amounts of 

coarse materials in the laboratory. However, when samples 

of stormwater are analyzed for a wide range of constituents, 

it is often necessary to split samples of water in the field into 

representative aliquots to satisfy different analytical methods. 

In this study, samples of highway runoff were split directly 

from the Teflon-lined bottle as described earlier. This method 

eliminated contact of the sample with additional processing 

equipment and reduced the potential for contamination. To 

determine the limitations of this method, a mixture of sediment containing five particle-size ranges of known mass was 

added to 12 L of deionized water and poured into a typical 

20-L Teflon-lined bottle. Samples of the sediment/water mixture of near equal volume were dispensed into 1-L bottles, and 

the concentration of each particle-size range was determined.

The method used in this study for splitting samples of 

water containing different size fractions of solids from the 

automatic sampler bottle into representative aliquots was 

evaluated under controlled conditions. Using the methods 

described earlier, 14 sequential replicate samples were collected from a 20-L bottle with an inner Teflon bag containing 

12 L of water and a sediment concentration of 1,424 mg/L. 

The total concentration of suspended sediment and the concentrations for five particle-size ranges were determined for each 

sample. The mean and relative standard deviation for each 

particle-size range calculated from these data are presented in 

table 13. Concentrations of suspended-sediment particles less 

than 0.063 mm in diameter in samples split from the sediment/

water mixture were both accurate and precise. However, the 

variability in suspended-sediment concentrations in samples 

of the sediment/water mixture increased for each size class as 

the diameter of the sediment particles increased. In part, this 

decrease in precision is a function of fewer particles being 

split into a limited number of bottles. These results are not 

uncommon among splitting devices. Results of experimental 

tests conducted by the USGS (Capel and Larson, 1996; Capel 

and nacionales, 1995; Selbig and others, 2007) indicate that 

concentrations of coarse sediments collected from a churn 

splitter can deviate from the true concentration by as much 

as 65 percent, and the relative standard deviation for samples 

split by a cone splitter range from about 21 to 45 percent. 

Although the reported results indicate that samples containing 

coarse sediment may be more precisely collected with a cone 

splitter, the large and sometimes unpredictable volumes of 

water collected during storms would require multiple passes 

through the cone splitter and, because the error is additive, the 

device may be less effective than the sample splitting method 

used in this study. Fortunately, the lack of precision in splitting 

coarse sediments has only marginal effects on the concentrations of many constituents affiliated with suspended sediment 

because most metals and SVOCs tend to be more concentrated 

on the particles less than 0.063 mm in diameter.

Chemical Quality and Particle Size of 

Suspended Sediment, Soil Samples, and Other 

Miscellaneous Samples

Standard reference samples were submitted to laboratories to identify potential contamination bias and to assess 

analytical method performance. Replicate samples of background soils, highway-berm soils, suspended sediment, and 

other miscellaneous samples were collected to determine the 

precision of the data.

Reference Samples

Five blind samples of standard reference soil (National 

Institute of Standards and Technology, 2003) from the 

National Institute of Standards and Technology (NIST) 
52 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

containing high levels of trace elements were submitted 

simultaneously with samples of background soils, highwayberm soils, highway runoff sediment, and other miscellaneous samples for analysis of elements. Standard reference 

soil was analyzed to determine both total concentrations and 

total-recoverable concentrations of 32 elements. Concentrations that are certified by the NIST are based on measurements 

obtained by two or more independent analytical techniques 

used by multiple laboratories. Concentrations of total metals, which are measured in samples completely digested by 

hydrofluoric acid, are certified by the NIST and provide the 

best estimate of the true concentration. For some elements, 

noncertified concentration data are provided by the NIST for 

informational purposes only. Leachable concentrations of the 

elements also are available for reference material. Concentrations of total-recoverable metals determined under mild 

leaching conditions that only partially digest the solids are not 

certified by the NIST but do provide quality-control data for 

the USEPA digestion method 3050B used predominantly in 

this study. Results of total-recoverable digestion procedures 

are generally considered by the USEPA to be an indication 

of bioavailability of trace elements (U.S. Environmental 

Protection Agency, 1986).

For about 40 percent of the measured elements for which 

there were certified concentration values in the standard 

reference soil, median total concentrations in blind samples 

were within the certified concentration ranges (table 14). For 

those elements that were outside the certified concentration 

ranges, the median total concentrations (except for antimony 

(Sb)) were within 15 percent of the lower certified concentration ranges. Median concentrations of total aluminum (Al), 

copper (Cu), K, Mn, nickel (Ni), and vanadium (V) fall within 

about 4 percent of the certified concentrations ranges; median 

concentrations for lead (Pb), Sb, titanium (Ti), and zinc (Zn) 

fall within about 6 to 15 percent from the certified concentration ranges. The relative standard deviations for concentrations 

in the blind samples range from 1 to 7 percent, indicating 

that the measurements are relatively precise (table 14). The 

median concentrations in blind samples with the measured 

elements for which there are noncertified values generally 

were less than, but within 20 percent of, the noncertified 

values. Median concentrations of total cobalt (Co), chromium 

(Cr), lanthanum (La), tungsten (W), and yttrium (Y) in blind 

samples were about 14 to 20 percent less than the noncertified 

total values for the NIST reference material (table 14). The 

median concentrations of total molybdenum (Mo), scandium 

(Sc), and strontium (Sr) in blind samples are within 5 percent 

of the noncertified total values for the NIST reference material (table 14). The relatively close agreement between known 

values and analytical results from blind samples demonstrates 

that the analytical methods generally were accurate.

Concentrations for total-recoverable elements in NIST 

reference material also are presented in table 14 with the 

associated NIST recovery (or leach) range for each element. 

Because total-recoverable concentrations are determined using 

partial digestion methods, the total-recoverable concentration 

generally is lower than the total concentration; however, the 

entire concentration can sometimes be recovered even using 

the weaker digestion method if the element is completely 

labile. As a result, many of the concentrations of elements that 

were determined using different digestion methods are similar. 

The median total-recoverable concentrations for all elements 

with available reference criteria were within the NIST reported 

recovery ranges, except for the median total-recoverable 

concentrations of arsenic (As), K, and P. The median totalrecoverable concentrations for As and K were about 3 and 8 

percent higher than the upper recovery range for the reference 

material, respectively. However, the variability in recovery of 

these elements was within the respective recovery range. The 

median total-recoverable concentration for P was about 15 

percent lower than the lower recovery range for the reference 

material. These data indicate that the total-recoverable concentrations for this element may exhibit a negative bias.

Inorganic blank water was spiked with known amounts 

of the NIST reference material to test for differences among 

total-recoverable concentrations digested using the USEPA 

method 3050B, the whole-water-in-bottle digestion method 

(Garbarino and Hoffman, 1999), and the alkaline persulfate 

digestion method (Patton and Kryskalla, 2003). The latter two 

methods were used predominantly to determine total-recoverable concentrations for metals and total P, respectively, in 

samples of highway runoff. Concentrations in parts per million 

of total-recoverable elements in samples of the sediment/water 

mixture were calculated on the basis of the mass of blank 

water and reference material, and the reported concentration 

for each element in milligrams per liter. Total-recoverable 

concentrations of Cu and Pb in the samples of the sediment/

water mixture were similar to the respective measurements 

made using USEPA method 3050B; however, the total-recoverable concentrations of the other elements in the samples of 

the sediment/water mixture were lower than the respective 

measurements made using USEPA method 3050B (table 14). 

Total-recoverable concentrations of Cr, Fe, Ni, P, and Zn in 

the samples of the sediment/water mixture were lower than the 

lower recovery range for the reference material. These data do 

not indicate a process failure in the analytical method because 

partial digestion methods often provide dissimilar results. 

The in-bottle digestion method described by Garbarino and 

Hoffman (1999) partially digests whole-water samples with 

nitric acid, whereas USEPA method 3050B digests samples 

with repeated additions of nitric acid and hydrogen peroxide, 

followed by additions of hydrochloric acid and sample refluxing. Coincidently, USEPA method 3050B is the method by 

which the ranges of leachable concentrations are determined 

for the reference material (National Institute of Standards and 

Technology, 2003). Although the results obtained by nitricacid digestion often are slightly lower than results obtained 

by the USEPA method, the precision of the in-bottle digestion 

method is greater because hydrochloric acid can cause spectral 

inference in the latter method (Garbarino and Hoffman, 1999). 

The difference between concentrations of P for each method 

also can be explained by the different digestion procedures 
Data Quality

53

Table 14. Median values and relative standard deviations for selected concentrations of total and total-recoverable metals in quality-control samples consisting of National Institute of Standards and Technology standard reference soil.[NIST, National Institute of Standards and Technology; RSD, relative standard deviation; ppm, parts per million; --, no data available; >, greater than; ±, plus or minus; total-recoverable concentrations are comparable to NIST-reported leachable concentrations. Blind sample analytical results are for five samples of the standard reference soil and two artificial water samples consisting of a mixture of inorganic blank water and the standard reference soil submitted separately to laboratories during this study]

Element

NIST standard reference soil

reported concentrations Standard reference soil blind sample analytical results

Certified total value 

(ppm)

Leach range

concentrations

(ppm)

Total concentration Total-recoverable concentration Total-recoverable concentration for reference soil in deionized water

Median

concentration

(ppm)

RSD

Median

concentration 

(ppm)

RSD

Average

concentration 

(ppm)

RSD

Aluminum 64,400 ± 800 12,000–26000 63,100 4 20,800 8 -- --

Arsenic 626 ± 38 490–600 635 5 616 2 -- --

Barium 707 ± 51 300–400 701 1 328 7 -- --

Calcium 12,500 ± 300 3,800–4,800 12,200 2 4,000 9 -- --

Cadmium 21.8 ± 0.2 13–26 22 4 21 1 16.4 1

Cobalt 101 6.3–12 8 7 8 6 -- --

Chromium 381 15–23 31 1 23 15 9 2

Copper 2,950 ± 130 2,400–3,400 2,700 2 2,820 3 2,774 1

Iron 33,800 ± 1,000 22,000–32,000 33,400 2 26,600 9 19,176 1

Lanthanum 341 -- 27.9 3 19.5 6 -- --

Potassium 21,100 ± 1,100 3,700–5,000 19,300 2 5,400 11 -- --

Magnesium 8,530 ± 420 4,300–6,000 8,300 2 5,400 7 -- --

Manganese 10,100 ± 400 6,200–9,000 9,320 4 8,160 6 7,499 1

Molybdenum 191 13–27 18 5 17 5 -- --

Sodium 11,400 ± 600 490–620 11,000 5 600 23 -- --

Nickel 14.3 ± 1.0 8.8–15 13 7 13 8 6.91 1

Phosphorus 1,060 ± 150 1,060–1,100 1,000 0 900 6 860 2

Lead 5,532 ± 80 4,300–7,000 5,000 3 5,140 4 5,127 2

Antimony 38.4 ± 3 -- 44 5 -- --

Scandium 8.71 -- 8.5 3 4.4 23 -- --

Silver 35.3 ± 1.5 24–30 >10 -- >10 -- -- --

Strontium 3301 94–110 321 3 102 6 -- --

Titanium 2,830 ± 100 920–1,100 2,400 3 1,100 8 -- --

Tungsten 931 -- 80 0 60 8 -- --

Vanadium 76.6 ± 2.3 37–50 73 3 49 7 -- --

Yttrium 231 -- 19 3 13.3 6 -- --

Zinc 6,952 ± 91 5,200–6,900 5,820 4 5,870 5 4,919 2

1Noncertified value.
54 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

used in the various methods. The alkaline persulfate digestion 

method (Patton and Kryskalla, 2003), which provides results 

statistically similar to those for samples digested by Kjeldahl 

method, is a weaker digestion method. These data indicate 

that whole-water concentrations of Cr, Fe, Ni, P, and Zn that 

are estimated from sediment data will exhibit a positive bias 

when compared to the whole-water concentrations determined 

by the in-bottle digestion method, assuming that dissolved 

concentrations of the elements are ignored.

Replicate Samples

Replicate samples of background soils, highway-berm 

soils, suspended sediment, and other miscellaneous materials, 

including samples of highway-maintenance sand, roadside 

grass, and solids discharged from the outlet pipe at the primary 

monitoring station on Interstate 495 were collected to determine the precision of the data. General statistics for the RPDs 

for 17 pairs of samples are presented in table 15. The average 

RPD was less than 10 percent for all elements except As, Na, 

Pb, Sc, and Ti. For these elements, the average RPD between 

replicate pairs ranged from about 11 to 16 percent. The maximum RPDs between replicate pairs for all elements, except 

for As, Co, Mo, Pb, Sc, and Ti, were less than 20 percent. 

The precision of the measurements of environmental samples 

(table 15) was less than the precision of the measurements 

of the reference materials (table 14). However, the environmental samples of soil and sediments were not milled prior 

to laboratory analysis, unlike the NIST reference material, so 

that comparisons could be made later between concentrations 

of metals in soils and sediment and concentrations in whole 

water samples. Because the environmental samples were not 

milled, greater variability between replicate pairs of samples 

was expected.

Particle Size

The variability in the distribution of particles sizes 

associated with replicate split samples of berm material and 

some soil samples also was assessed because small changes 

in the overall content of silt- and clay-size particles that 

contain disproportional amounts of many elements can affect 

the elemental concentration in the aggregate. The median 

RPDs for the amounts of material in particle-size classes less 

than 0.063 mm in diameter, from 0.063 mm to 0.250 mm in 

diameter, and greater than 0.250 mm in diameter for 16 replicate pairs were 7, 8, and 4 percent, respectively. The RPDs 

between the amounts of material in the particle-size class less 

than 0.063 mm in diameter were less than 20 percent for about 

90 percent of the replicate pairs. The maximum RPDs between 

the amounts of material in particle-size classes less than 

0.063 mm in diameter, from 0.063 mm to 0.250 mm in diameter, and greater than 0.250 mm in diameter were 36, 19, and 

26 percent. Although these data indicate that the distribution 

of particle sizes in split samples was generally precise, some 

of the variability observed in the concentrations of elements 

in replicate pairs could, in part, result from differences in the 

distribution of particle sizes in the samples.

Quality of Highway Runoff

Physical characteristics and concentrations of 6 dissolved 

major ions, total N, total P, 8 total-recoverable metals, 24 

SVOCs (including priority PAHs and phthalate compounds), 

and suspended sediment in highway runoff samples are 

presented in table 16 (in the back of the report). Concentrations of 73 organic compounds, including an additional 62 

organic compounds, which were measured in fewer samples 

and include selected organic compounds generally found in 

urban and industrial wastewater discharges, are presented in 

table 17 (in the back of the report). These data document the 

chemistry of runoff from Massachusetts highways during 

2005–07, as sampled at the four primary monitoring stations, 

four secondary monitoring stations, and the four monitoring 

stations on the test highways. The data also are provided in 

digital form in the HRBD (appendix A) that was developed by 

USGS, in cooperation with the Federal Highway Administration (Granato and Cazenas, 2009). Various summary statistics 

for the highway-runoff data presented in tables 16 and 17 can 

be generated by use of the database, as described by Granato 

and Cazenas (2009).

Several types of analyses were conducted with the data to 

evaluate their suitability for the development of planning-level 

estimates and other applications. Concentrations of highwayrunoff constituents from primary, secondary, and test stations 

were compared to determine whether significant differences 

exist among the stations, or whether data from the multiple 

stations can be aggregated. Relations of constituent concentrations to traffic volume were investigated. The effects of seasonality on concentrations also were examined. The frequent 

measurements of specific conductance during storms and 

relations developed between specific conductance and element 

concentrations allowed for a detailed characterization of the 

components of road salt in the highway runoff at the monitoring stations. A probability distribution for concentrations and 

loads of Cl in highway runoff and descriptive statistics for the 

major constituents in road salt were computed on the basis of 

available continuous records of flow and specific conductance 

for the entire monitoring period. Potential contributions of 

highway constituents were estimated on the basis of the chemistry of available soil, berm materials, and highway-maintenance material data, and published source reference data. 

Finally, the relation of concentrations of selected constituents 

to suspended sediment was evaluated. In some of the analyses, 

concentrations of constituents in suspended sediment, constituents in soil samples collected near highways, and other solidphase matrices were used in the interpretation of the highway 

runoff data. Constituent concentrations in samples of sieved 

suspended sediments, soils, and highway berms are presented 

in tables 18 through 21.
Quality of Highway Runoff 55

Table 15. Relative percent differences between 17 replicate pairs for samples of background soils, highway-berm soils, suspended 

sediment, and other miscellaneous samples collected from and near highways in Massachusetts, 2005–07.

Element

Relative percent difference between replicate pairs

Minimum

(percent)

Average

(percent)

Median

(percent)

Maximum

(percent)

Relative standard 

deviation

(percent)

Aluminum 0.0 5.6 8.2 9.9 66

Arsenic 0.0 14.7 22.2 22.2 67

Barium 1.6 7.1 9.5 9.5 43

Beryllium 0.0 7.7 7.7 15.4 141

Calcium 0.0 1.5 0.0 10.5 216

Cobalt 0.0 2.9 0.0 30.8 293

Chromium 0.8 3.9 3.3 12.2 73

Copper 0.6 5.2 6.0 10.0 46

Iron 0.6 4.6 6.2 8.0 53

Potassium 0.0 5.6 8.0 9.5 63

Lanthanum 1.3 4.8 5.6 5.9 32

Lithium 0.0 6.8 9.5 9.5 60

Magnesium 0.0 1.3 0.0 10.5 217

Manganese 0.0 6.9 10.1 10.1 56

Molybdenum 0.0 2.9 0.0 22.2 217

Sodium 0.0 11.0 18.2 18.2 80

Nickel 0.0 0.7 0.0 11.5 412

Phosphorus 0.0 0.6 0.0 9.5 412

Lead 0.0 16.1 28.6 28.6 85

Scandium 0.0 12.2 12.8 46.2 82

Strontium 0.8 3.9 3.8 8.5 42

Titanium 0.0 13.3 15.4 40.0 75

Vanadium 0.0 4.7 6.1 6.1 43

Yttrium 0.0 7.8 11.1 11.4 56

Zinc 0.7 3.8 3.0 15.6 94

Zirconium 3.5 9.9 10.1 14.6 28
56 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Intrasite Evaluation of Constituents in Samples 

of Runoff from the Principal Highways

The primary and secondary monitoring stations were 

located along principal highways (table 1). Paired primary 

and secondary sites were located within a few miles of each 

other on a section of highway with limited access to ensure 

comparable levels of traffic volume and density. Although the 

design and operation of the primary and secondary monitoring stations were similar, the monitoring period and number 

of samples of highway runoff collected at the primary stations were greater than at the secondary stations. Populations 

of concentration data for constituents in samples routinely 

collected at the secondary monitoring stations on each of 

the principal highways were compared to the populations of 

concentration data for associated primary monitoring stations 

to determine whether the variability between the data was 

significantly different or whether the data could be aggregated. 

The nonparametric Mann-Whitney test was used to determine 

whether the independent populations were statistically different (p value less than 0.05). For constituents whose concentrations either were not detected or were estimated to be less than 

the LTMDL (censored data), concentrations were set equal 

to a value less than the respective LTMDL. This approach is 

appropriate for rank-based nonparametric methods for singly 

censored data (Helsel, 2005). Analyses for many PAH and 

phthalate compounds were not performed because they either 

were not detected in the samples or all of the concentrations 

were estimated to be less than the LTMDL.

With a few exceptions, results of tests of paired populations of individual constituent concentrations, where sufficient 

data were available, generally indicate that the populations 

were not significantly different at a 95-percent confidence 

interval for each pair of sites on the principal highways. The 

resultant p values for each of the principal highways are listed 

in table 22. Results of tests between paired populations of 

concentrations of all constituents in samples collected at the 

monitoring stations on Route 119, except suspended sediment 

less than 0.063 mm in diameter, indicate no significant difference (table 22). The difference between the median concentrations of suspended sediment less than 0.063 mm in diameter 

for each site is about 19 mg/L or about 22 percent. The lack of 

significance observed in the test between paired populations 

of concentrations of suspended sediment with particles less 

than 0.063 mm in diameter may be the result of runoff patterns 

associated with the secondary monitoring station that differed 

from those at the primary monitoring station. For example, a 

pair of parallel ruts in each travel lane on the road surface in 

the drainage area of the secondary monitoring station (fig. 17) 

often caused smaller flows to bypass the catch basin; furthermore, frost heaves in the roadway within the drainage area 

of the secondary monitoring station also diverted water away 

from the catch basin during the winter when runoff concentrations of suspended sediment are generally high as a result of 

winter sanding. It is plausible that these factors affected the 

flow patterns sufficiently to introduce bias into the sample 

population of sediment concentrations less than 0.063 mm in 

diameter at the secondary monitoring station on Route 119. 

Tests between paired populations of concentrations for all 

constituents in runoff collected at the monitoring station on 

Route 2, except for concentrations of total-recoverable Zn, 

also determined no significant difference (table 22). For this 

highway, the median concentration of total-recoverable Zn in 

composite samples of highway runoff at the primary station 

(308 mg/L) was about twice as high as the median concentration measured in composite samples at the adjacent secondary 

station (152 mg/L). The significant difference resulting from 

the test between paired populations of total-recoverable Zn is 

not fully explainable with available data. Tests between paired 

populations of constituent concentrations from the monitoring stations on Interstate 495, except for concentrations of 

suspended sediment less than 0.063 mm in diameter, also 

determined no significant difference (table 22). The difference 

between the median concentrations of suspended sediment 

less than 0.063 mm in diameter for each set of paired sites was 

about 34 mg/L or about 41 percent. The significant difference 

between the paired populations of concentrations of suspended 

sediment is likely attributable to berm material that eroded 

onto the roadway surface in the drainage area of the primary 

monitoring station because the height of the berm along the 

highway at the secondary monitoring station was lower than 

the berm at the primary monitoring station and showed little 

evidence of erosion. Results for all tests between paired 

populations of constituent concentrations in samples from the 

monitoring site on Interstate 95 (table 22) indicate that the 

populations are not significantly different from each other. A 

greater number of constituents were tested for this highway 

than for other highways because the frequency of detection for 

most PAH and phthalate compounds was greater here than at 

other highways.

In summary, there were few significant differences 

between constituent concentrations in samples collected 

at primary and secondary sites on the principal highways. 

Consequently, in subsequent analyses, data from the primary 

and secondary monitoring stations were combined to characterize the quality of runoff from the principal highways. For 

those tests between populations of suspended sediment less 

than 0.063 mm in diameter, it was unusual that the concentrations of fine sediment were significantly different between 

the paired stations on Route 119 and Interstate 495. Yet, 

concentrations of no other constituents were significantly 

different between the paired sites for each highway because 

the concentrations of many elements generally are greater on 

the fine sediment fraction than on the coarser sand fractions 

(table 18 in the back of the report). Alternatively, the effects of 

the distributions of sediment particle size, concentration, and 

associated sediment chemistry may be small if the dissolved 

fraction of the total-recoverable metals was high in samples of 

runoff. Other studies that included analyses for concentrations 

of filtered composite samples have shown that the concentrations of some dissolved trace elements can account for about 

10 to 65 percent of the total concentration (Smith, 2002; 
Quality of Highway Runoff 57

Table 22. Resultant p values for Mann-Whitney tests for paired populations of constituent concentrations for highway runoff 

collected from the primary and secondary stations on four principal highways in Massachusetts, 2005–07.

[<, Less than value shown; --, insufficient detections to perform test; mm, millimeters in diameter; shaded areas indicate values that are significant at a 95-percent confidence interval]

Constituent Route 119 Route 2 Interstate 495 Interstate 95

Chloride 0.467 0.429 0.672 0.710

Sodium 0.445 0.401 0.672 0.204

Calcium 0.813 0.303 0.410 1.000

Magnesium 0.580 0.565 0.963 0.108

Potassium 0.772 0.848 1.000 0.108

Sulfate 0.564 0.905 0.869 0.281

Nitrogen, total 0.407 0.867 0.742 0.632

Phosphorus, total 0.920 0.737 0.258 0.701

Cadmium 0.520 0.061 0.888 0.314

Chromium 0.340 0.810 0.796 0.886

Copper 0.514 0.867 0.347 0.517

Iron 0.564 0.867 0.204 1.000

Lead 0.900 0.774 0.397 0.270

Manganese 0.900 0.829 0.452 0.649

Nickel 0.633 0.829 0.605 0.581

Zinc 0.861 0.010 0.452 0.719

Fluorene -- -- -- --

Acenaphthene -- -- -- 1.000

Acenaphthylene -- -- -- --

Anthracene -- -- -- 0.423

Benzo[a]anthracene 1.000 0.744 0.234 0.734

Benzo[a]pyrene 0.568 0.293 0.125 0.827

Benzo[b]fluoranthene 0.949 0.623 0.165 0.905

Benzo[ghi]perylene 0.775 0.971 0.223 0.595

Benzo[k]fluoranthene -- 0.437 0.570 0.829

Benzyl n-butyl phthalate -- -- 0.970 0.282

Bis(2-ethylhexyl) phthalate 0.153 0.848 0.772 0.290

Chrysene 0.736 0.585 0.126 0.848

Dibenzo[a,h]anthracene -- -- -- --

Diethyl phthalate -- -- -- 0.598

Dimethyl phthalate -- -- -- --

Di-n-butyl phthalate -- 0.163 0.107 0.975

Di-n-octyl phthalate 0.784 0.692 0.484 0.103

Fluoranthene 0.687 0.449 0.126 0.649

Indeno[1,2,3-cd]pyrene -- 0.423 0.532 0.632

Nitrobenzene -- -- -- --

Phenanthrene 0.840 0.482 0.100 0.360

Pyrene 0.949 0.566 0.066 0.684

Naphthalene -- -- -- --

Perylene -- -- 0.324 0.294

Suspended sediment 0.230 0.821 0.034 0.737

Suspended sediment < 0.063 mm 0.003 0.688 0.001 0.157
58 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 17. Ruts on the roadway surface running parallel with the road that often caused small flows to bypass the catch basin at 

the secondary highway-monitoring station on Route 119 in Ashburnham, Massachusetts.
Quality of Highway Runoff 59

Breault and Granato, 2000). The partitioning of metals from 

the dissolved, colloidal, and solid states is poorly understood. 

Various factors, including pH, ionic strength, temperature, 

hardness, concentration of anions and suspended sediment, 

oxidation reduction potential, and in some cases, the presence 

of other trace elements (Bricker, 1999) can affect the partitioning process in runoff. The duration that the sample remains 

in the sample bottle prior to processing also can affect the 

partitioning process as well. Unfortunately, characterization of 

the dissolved phase of constituents was outside of the scope of 

this study.

Inter-Site Evaluation of Constituents in Runoff 

from Test Highways and Principal Highways

Populations of all concentration data for runoff collected from the test highways were compared to populations 

of concentration data from the principal highways of similar 

AADT volumes to determine whether the data were transferable from highway to highway on the basis of AADT volume. 

Statistically similar sample populations for the primary and 

secondary stations on the principal highways were combined 

into one data set. Results of Mann-Whitney tests were used 

to determine whether the independent populations from the 

paired highways were statistically different (p value less than 

0.05). As previously indicated, censored concentrations of any 

constituent were set equal to a value less than the LTMDL.

Mann-Whitney tests were performed between populations of constituent concentrations in samples from the 

monitoring stations on three principal highways and four test 

highways—Route 119 and Route 8 (low ADDT volume), 

Route 2 and Interstate 190 (moderate AADT volume), Route 

2 and Interstate 195 (moderate AADT volume), and Interstate 

95 and Interstate 93 (very high AADT volume). The resulting p values for each of the tests are listed in table 23. Where 

sufficient concentration data were available for testing, the 

results showed no significant difference between populations 

of constituent concentrations collected from the sites on Route 

119 and Route 8, and only populations of total-recoverable 

Zn were significantly different in test results for Route 2 and 

Interstate 190. Consequently, the significant difference may 

be attributable to the high total-recoverable Zn concentrations 

observed at the primary monitoring station on Route 2. The 

test results for populations of total-recoverable Zn concentrations in samples only from the secondary station on Route 2 

and the test station on Interstate 190 indicate that populations 

were not significantly different (p value = 0.213). Results 

for most tests between populations of constituent concentrations in samples collected from the stations on Route 2 and 

Interstate 195, and for stations on Interstate 95 and Interstate 

93, indicate that the populations of several constituents were 

significantly different. Results of tests between populations of 

concentrations of dissolved Ca and K, total P, and total-recoverable Cd, Cr, Cu, Mn, and Zn in samples from the stations on 

Route 2 and on Interstate 195 indicate that populations were 

significantly different. Test results between populations of concentrations of total N; dissolved Mg, Na, Cl, SO4

; total-recoverable Cu, Fe, Pb, and Ni; suspended sediment; and PAH and 

phthalate compounds, where sufficient data were available, 

indicate populations or concentrations were not significantly 

different. Because the concentrations of total-recoverable Zn 

at the primary monitoring station on Route 2 were significantly higher than at the test monitoring stations, another test 

was performed between the populations of total-recoverable 

Zn concentrations collected from the secondary station on 

Route 2 and the station on Interstate 195. However, results 

from this test also indicated that the two populations were 

significantly different (p value = 0.017). Because winter-maintenance sanding generally is not practiced on Interstate 195 

in the vicinity of the monitoring location (Roy Fierra, Massachusetts Department of Transportation, written commun., 

2006), Mann-Whitney tests also were performed on a subset 

of concentrations of total P and total-recoverable Cd, Cr, Cu, 

Mn, and Zn that excluded concentrations in samples collected 

during winter storms at the Route 2 monitoring locations. 

These test results indicate that populations of total-recoverable 

Cr, Mn, and Zn collected from the stations on Route 2 and on 

Interstate 195 remain significantly different at a 95-percent 

confidence interval.

The monitoring station on Interstate 195 is located near 

Cape Cod and USEPA level III ecoregion 84 where the soil 

and vegetation are different than at the monitoring station 

on Route 2. Background soils can be deposited on the highway by hydraulic erosion of the roadway berm, or directly 

deposited on the road by automobiles. As a result of these 

processes, local soils can be a large part of the suspended 

sediment in highway runoff (Gupta and others, 1981) and 

may provide a base concentration for total P and many metals. 

Analysis of samples of soil collected along both highways 

indicate that concentrations of elements were lower near the 

Interstate 195 station than concentrations near the stations on 

Route 2 (fig. 18). In fact, concentrations of total P and totalrecoverable Cr, Cu, Fe, Ni, Mn, Pb, and Zn in samples of soil 

collected along Interstate 195 were consistently lower than the 

concentrations of the same constituents collected along six of 

the other highways (fig. 18) located in Massachusetts. Because 

concentrations of suspended sediment were not significantly 

different between the two highways, it is reasonable to conclude that highways with similar anthropogenic-enrichment 

rates may produce runoff of dissimilar quality, depending on 

the base quality of the local soils.

These findings indicate that it may be unwise to use 

descriptive statistics generated by data sets of similar AADT 

volumes to estimate constituent loads for highways located in 

the southeastern coastal areas of Massachusetts and USEPA 

level III ecoregion 84 because the use of the descriptive statistics may result in grossly overestimated loads.

Concentrations of most total-recoverable metals in composite samples of highway runoff collected on Interstate 93 

were considerably higher than the concentrations in composite 

samples from Interstate 95. Results for Mann-Whitney tests 
60 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 18. Distribution of concentrations of selected constituents in samples of soil collected in the vicinity of seven 

highway-runoff monitoring sites in Massachusetts, 2005–07.

10

100

1,000

10,000

 MANGANESE

CONCENTRATION, IN PARTS PER MILLION

Route 119

Interstate 195

Route 2

 Interstate 495

Route 8

 Interstate 95

 Interstate 93

 CHROMIUM

100

1,000

10,000

CONCENTRATION, IN PARTS PER MILLION

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION
Quality of Highway Runoff 61

Figure 18. Distribution of concentrations of selected constituents in samples of soil collected in the vicinity of seven 

highway-runoff monitoring sites in Massachusetts, 2005–07.—Continued

1

10

100

1,000

 COPPER

CONCENTRATION, IN PARTS PER MILLION

Route 119

Interstate 195

Route 2

 Interstate 495

Route 8

 Interstate 95

 Interstate 93

1

10

100

1,000

 LEAD

CONCENTRATION, IN PARTS PER MILLION

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION
62 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 18. Distribution of concentrations of selected constituents in samples of soil collected in the vicinity of seven 

highway-runoff monitoring sites in Massachusetts, 2005–07.—Continued

1

10

100

1,000

ZINC

CONCENTRATION, IN PARTS PER MILLION

Route 119

Interstate 195

Route 2

 Interstate 495

Route 8

 Interstate 95

 Interstate 93

1

10

100

 NICKEL

CONCENTRATION, IN PARTS PER MILLION

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION
Quality of Highway Runoff 63

Figure 18. Distribution of concentrations of selected constituents in samples of soil collected in the vicinity of seven 

highway-runoff monitoring sites in Massachusetts, 2005–07.—Continued

0.1

1

10

 IRON

CONCENTRATION, IN PERCENT

Route 119

Interstate 195

Route 2

 Interstate 495

Route 8

 Interstate 95

 Interstate 93

0.001

0.01

0.1

1

 PHOSPHORUS

CONCENTRATION, IN PERCENT

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION
64 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 23. Resultant p values for Mann-Whitney tests for paired populations of constituent concentrations in highway runoff collected 

from three stations on principal highways and four stations on the test highways in Massachusetts, 2005–07.

[<, Less than value shown; --, insufficient detections to perform test; mm, millimeters in diameter; shaded areas indicate values that are significant at a 95-percent confidence interval]

Constituent

Route 119

and

Route 8

Route 2

and

Interstate 190

Route 2

and

Interstate 195

Interstate 95

and

Interstate 93

Chloride 0.177 0.067 0.598 0.298

Sodium 0.248 0.082 0.633 0.407

Calcium 0.091 0.542 0.045 0.951

Magnesium 0.271 0.429 0.103 0.821

Potassium 0.554 0.288 0.008 0.744

Sulfate 0.959 0.946 0.303 0.821

Nitrogen, total 0.119 0.701 0.167 0.451

Phosphorus, total 0.362 0.560 0.039 0.092

Cadmium 0.096 0.342 0.044 0.108

Chromium 0.194 0.603 0.013 0.040

Copper 0.119 0.378 0.280 0.011

Iron 0.917 0.821 0.126 0.026

Lead 0.119 0.343 0.498 0.021

Manganese 0.568 0.769 0.014 0.033

Nickel 0.568 0.946 0.259 0.060

Zinc 0.697 0.040 0.001 0.022

Fluorene -- -- -- 0.412

Acenaphthene -- -- -- --

Acenaphthylene -- -- -- 0.690

Anthracene -- -- -- 0.084

Benzo[a]anthracene 0.810 0.431 0.255 0.090

Benzo[a]pyrene 0.701 -- 0.168 0.403

Benzo[b]fluoranthene 0.872 -- 0.266 0.114

Benzo[ghi]perylene -- -- -- 0.522

Benzo[k]fluoranthene -- -- -- 0.114

Benzyl n-butyl phthalate -- -- 0.527 0.360

Bis(2-ethylhexyl) phthalate 0.162 -- 0.711 0.019

Chrysene 0.789 -- 0.184 0.145

Dibenzo[a,h]anthracene -- -- -- --

Diethyl phthalate -- -- 0.174 0.159

Dimethyl phthalate -- -- -- --

Di-n-butyl phthalate -- -- 0.681 0.806

Di-n-octyl phthalate 0.091 -- 0.820 0.031

Fluoranthene 0.900 0.752 0.496 0.139

Indeno[1,2,3-cd]pyrene -- -- -- 0.472

Nitrobenzene -- -- -- --

Phenanthrene 0.091 -- 0.583 0.175

Pyrene 0.900 0.846 0.451 0.103

Naphthalene -- -- -- 0.174

Perylene -- -- -- 0.679

Suspended sediment 0.258 0.363 0.065 0.020

Suspended sediment < 0.063 mm 0.615 0.073 0.194 0.238
Quality of Highway Runoff 65

between populations of concentrations of total-recoverable 

metals, except for Cd and Ni, and suspended sediment collected from the stations on Interstate 95 and Interstate 93 were 

significantly different at a 95-percent confidence interval. 

No significant differences were found between populations 

of concentrations of total nutrients, major ions, and SVOCs. 

Concentrations of total-recoverable Cu, Pb, and Zn in local 

soils near the monitoring station on Interstate 93 were greater 

than the concentrations present in soil samples collected near 

the monitoring stations on Interstate 95, as well as the other 

six highways (table 19 in the back of the report and fig. 18). 

Albeit these soil samples were collected at a distance of about 

30 ft from the edge of the highways and samples from other 

highways were collected at a distance of about 100 ft from the 

edge of the highways, the concentrations of many metals in 

soils adjacent to highways have been shown to decay exponentially (Jaradat and Momanі, 1999); thus even at about 30 ft 

from the highway edge, for many metals, concentrations in 

the soil may approach background concentrations. In part, the 

higher concentrations of Cu, Pb, and Zn in local soils near the 

monitoring station on Interstate 93 may explain some of the 

differences between the two populations for these constituents; 

however, concentrations of the other metals in samples of soil 

collected near the monitoring station on Interstate 93 were 

similar to concentrations present in soil samples collected near 

the monitoring stations on other highways. The concentrations 

of suspended sediment present in composite samples of highway runoff from the station on Interstate 93 were higher than 

in composite samples of highway runoff collected at stations 

on Interstate 95. This is likely the main factor in the significant difference between populations of metals. The median 

concentration of suspended sediment for the station on Interstate 93 (714 mg/L) is nearly an order of magnitude higher 

than the median concentration for the station on Interstate 95 

(87 mg/L).

Although the median concentration of suspended sediment for the monitoring station on Interstate 93 is based on 

only five measurements, data collected with nearly identical 

methods at three locations on Interstate 93 in 1999 and 2000 

(Smith, 2002) support the high concentrations of suspended 

sediment observed in this study. In fact, the median concentrations of most constituents in composite samples from the 

station on Interstate 93 in this study are within the interquartile range of the previous study (table 24); the exceptions are 

dissolved Ca, Cl, and Na; total-recoverable Cd, Cu, and Fe; 

and a few PAHs. Concentrations of dissolved Ca, Cl, and Na 

were lower than in the previous study likely because, in this 

study, fewer samples were collected during the winter when 

deicing compounds are applied than during the prior study 

when 50 percent of the samples were collected in the months 

of January and March. Concentrations of PAHs also tend to be 

higher during the colder months, so a similar bias is applicable. Concentrations of total-recoverable Cu and Fe were 

within about 3 percent of the upper quartile range. Results for 

Mann-Whitney tests for the respective data sets indicate the 

populations from the two studies are not statistically different 

at a 95-percent confidence interval, except for populations 

of acenaphthylene concentrations (table 24). Acenapthene 

concentrations were significantly different between the two 

populations at a slightly higher confidence interval.

The higher concentrations of suspended sediment in 

samples collected from Interstate 93 may be an artifact of the 

urban environment. Higher concentrations of airborne sediment build up near highway curbing, guardrails, and other 

barriers in highly urbanized areas that lack natural vegetation 

barriers that trap dust fall. Dry-deposition rates are reported to 

increase substantially from rural areas, which generally have 

low deposition rates, to urban areas, which have high deposition rates (Colman and others, 2001). In this study, impervious 

surface area (roofs, paved areas, concrete surfaces) is used in 

place of generalized land-use indexes to quantify urbanization. Concentration data for stations on highways in this study 

indicate that the amount of suspended sediment in samples of 

highway runoff increases with the amount of impervious area 

surrounding the sampling station on the highway (fig. 19). The 

amount of impervious area surrounding the Interstate 93 station is about twice that of the areas surrounding the Interstate 

95 stations, despite the fact that a substantial amount of land 

to the east of Interstate 93 consists of park land, river, and 

embayment. These data indicate that the quantity, as well as 

the quality, of sediment in highway runoff can be affected by 

the proximately to highly urbanized areas containing large 

amounts of impervious area. Thus, information on loads for 

Interstate 93 within the urbanized area may more accurately 

be determined from descriptive statistics generated by data 

collected specifically from Interstate 93 during this study and 

the previous study (Smith, 2002) than from data sets for other 

highways with similar AADT volumes.

Intersite Evaluation of Constituents in Samples 

of Runoff from the Principal Highways

Populations of all concentration data (table 16) collected 

from each principal highway (primary and secondary sites) 

were compared to populations from each of the other principal highways to determine whether the populations were 

significantly different from highway to highway. Results of 

the Mann-Whitney tests were used to determine whether the 

independent populations from each of the principal highways 

were statistically different (p value less than 0.05). As previously indicated, censored data values were set equal to a value 

less than the LTMDL for each constituent. For several PAH 

and phthalate compounds, analysis was limited by the lack 

of detections in samples of highway runoff. The resultant p

values for each of the constituents are listed in table 25.

Results indicate that, in general, concentrations of most 

constituents in composite samples collected at the monitoring 

stations on Route 119, were significantly different from those 

from the other three principal highways (table 25). Results of 

paired tests between populations of concentration data from 

Route 119 and each of the other principal highways show that 
66 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 24. Median and interquartile values and resultant p values for Mann-Whitney tests at a 95-percent confidence interval for 

paired populations of constituent concentrations in highway runoff collected from Interstate 93 in Massachusetts in 1999 through 2000 

and 2006 through 2007.

[mg/L, milligrams per liter; μg/L, micrograms per liter; mm, millimeters in diameter; shaded area indicates values that are significant at a 95-percent confidence 

interval]

Constituent

Interstate 93 

(1999–2000) 

25th percentile

Interstate 93 

(1999–2000) 

median

Interstate 93 

(1999–2000) 

75th percentile

Interstate 93

(2006–07) 

median

p-value

Calcium, filtered, mg/L 7.65 11 11 7.2 0.33

Magnesium, filtered, mg/L 0.60 0.70 0.80 0.75 0.86

Potassium, filtered, mg/L 1.3 1.5 1.8 1.38 0.79

Sodium, filtered, mg/L 31 54 155 25 0.79

Chloride, filtered, mg/L 46.5 76 245 31.2 0.93

Sulfate, filtered, mg/L 9.6 13 76 10.2 0.73

Total nitrogen, unfiltered, mg/L 1.87 2.54 3.12 2.09 0.28

Phosphorus, unfiltered, mg/L 0.29 0.44 0.62 0.34 0.59

Cadmium, unfiltered, μg/L 2 2 3 0.78 0.12

Chromium, unfiltered, μg/L 24.75 36 42 40 0.54

Copper, unfiltered, μg/L 107.5 140 172.5 178 0.71

Iron, unfiltered, μg/L 9,300 11,000 12,000 12,100 0.84

Lead, unfiltered, μg/L 74 95 112.5 75.6 0.62

Manganese, unfiltered, μg/L 210 230 280 220 0.71

Nickel, unfiltered, μg/L 15 17.5 20.5 18.2 0.97

Zinc, unfiltered, μg/L 477.5 575 935 613 0.90

Fluorene, unfiltered, μg/L 0.10 0.10 0.20 0.12 0.51

Acenaphthene, unfiltered, μg/L 0.10 0.10 0.10 0.07 0.05

Acenaphthylene, unfiltered, μg/L 0.10 0.10 0.20 0.06 0.00

Anthracene, unfiltered, μg/L 0.10 0.20 0.30 0.21 0.76

Benzo[a]pyrene, unfiltered, μg/L 0.50 0.60 0.90 0.73 0.69

Benzo[b]fluoranthene, unfiltered, μg/L 0.70 1.0 1.3 1.6 0.11

Benzo[ghi]perylene, unfiltered, μg/L 0.30 0.80 1.0 0.49 0.59

Benzo[k]fluoranthene, unfiltered, μg/L 0.40 0.50 0.90 0.63 1.00

Chrysene, unfiltered, μg/L 0.60 1.2 1.6 1.2 0.92

Fluoranthene, unfiltered, μg/L 1.1 1.6 2.3 2.0 0.69

Indeno[1,2,3-cd]pyrene, unfiltered, μg/L 0.30 0.60 0.90 0.43 0.62

Phenanthrene, unfiltered, μg/L 0.50 0.80 1.3 0.91 0.69

Pyrene, unfiltered, μg/L 1.0 1.4 2.2 1.6 0.84

Naphthalene, unfiltered, μg/L 0.14 0.20 0.20 0.07 0.31

Suspended sediment, mg/L 276 426 665 714 0.74

Suspended sediment < 0.063 mm, percent 43 71.6 86 21 0.27
Quality of Highway Runoff 67

Figure 19. Relation of the percentage of impervious area within a 1-mile radius 

around each of the 12 highway-runoff monitoring sites in Massachusetts to the median 

concentration of suspended sediment and annual average traffic volumes.

10

100

1,000

 MEDIAN CONCENTRATION OF SUSPENDED SEDIMENT, 

IN MILLIGRAMS PER LITER

PERCENTAGE OF IMPERVIOUS AREA WITHIN A 1-MILE RADIUS

0 10 20 30 40 50

10,000

200,000

100,000

1,000

EXPLANATION

Annual average daily 

traffic volume per day
68 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 25. Resultant p values for Mann-Whitney tests for paired populations of concentrations of highway-runoff constituents 

collected from the primary and secondary stations on the four principal highways in Massachusetts, 2005–07.

[<, Less than value shown; --, insufficient detections to perform test; mm, millimeters in diameter; shaded areas indicate values that are significant at a 95-percent confidence interval]

Constituent

Route 119

and

Route 2

Route 119

and

Interstate 495

Route 119

and

Interstate 95

Route 2

and

Interstate 495

Route 2

and

Interstate 95

Interstate 495 

and

Interstate 95

Chloride 0.705 0.847 0.424 0.838 0.825 0.676

Sodium 0.829 0.986 0.411 0.812 0.572 0.466

Calcium 0.382 0.236 0.003 0.974 <0.001 0.001

Magnesium 0.610 0.749 0.345 0.330 0.291 0.110

Potassium 0.068 0.544 0.007 0.138 0.143 0.003

Sulfate 0.263 0.285 0.023 0.863 0.008 0.019

Nitrogen, total 0.000 0.001 <0.001 0.896 0.015 0.013

Phosphorus, total 0.051 0.082 0.006 0.844 0.844 0.408

Cadmium <0.001 <0.001 <0.001 0.600 0.658 0.980

Chromium <0.001 <0.001 <0.001 0.670 0.436 0.325

Copper <0.001 <0.001 <0.001 0.363 0.041 0.310

Iron 0.091 0.009 0.061 0.577 0.737 0.572

Lead 0.004 0.001 <0.001 0.617 0.064 0.310

Manganese 0.065 0.024 0.010 0.774 0.306 0.476

Nickel 0.040 0.007 0.003 0.572 0.210 0.346

Zinc <0.001 <0.001 <0.001 0.053 0.075 0.774

Fluorene -- -- -- -- -- 0.954

Acenaphthene -- -- -- -- -- 0.975

Acenaphthylene -- -- -- -- -- --

Anthracene -- -- -- -- -- 0.626

Benzo[a]anthracene 0.003 0.002 0.030 0.612 0.395 0.766

Benzo[a]pyrene <0.001 <0.001 <0.001 0.808 0.162 0.295

Benzo[b]fluoranthene 0.005 0.006 <0.001 0.878 0.185 0.121

Benzo[ghi]perylene 0.283 0.097 0.002 0.385 0.017 0.149

Benzo[k]fluoranthene 0.011 0.007 <0.001 0.658 0.064 0.157

Benzyl n-butyl phthalate 0.841 0.834 0.144 0.920 0.193 0.280

Bis(2-ethylhexyl) phthalate 0.003 <0.001 <0.001 0.468 0.231 0.550

Chrysene 0.008 0.018 0.000 0.786 0.144 0.131

Dibenzo[a,h]anthracene -- -- -- -- -- --

Diethyl phthalate <0.001 <0.001 0.228 0.556 <0.001 <0.001

Dimethyl phthalate -- -- -- -- -- --

Di-n-butyl phthalate 0.893 0.876 0.316 0.911 0.239 0.340

Di-n-octyl phthalate 0.001 0.003 0.001 0.365 0.532 0.142

Fluoranthene 0.002 0.002 <0.001 0.967 0.148 0.244

Indeno[1,2,3-cd]pyrene 0.044 0.007 0.001 0.362 0.029 0.210

Nitrobenzene -- -- -- -- -- --

Phenanthrene 0.095 0.060 0.005 0.685 0.159 0.367

Pyrene 0.008 0.004 <0.001 0.771 0.066 0.184

Naphthalene -- -- -- -- -- 0.520

Perylene -- -- -- 0.093 <0.001 0.172

Suspended sediment 0.031 0.034 0.020 0.749 0.820 0.629

Suspended sediment < 0.063 mm 0.002 0.550 0.079 0.049 0.183 0.403
Quality of Highway Runoff 69

total N; total-recoverable Cd, Cr, Cu, Pb, Ni, and Zn; most 

PAH and phthalates compounds; and suspended sediment were 

significantly different at a 95-percent confidence interval.

Paired tests between populations of concentration 

data from Route 119 and Interstate 95 show that populations of concentrations of dissolved Ca, K, and SO4

; total P; 

benzo[ghi]perylene; and phenanthrene also were significantly 

different at a 95-percent confidence interval. Results of paired 

tests between populations of concentration data from Route 

2 and Interstate 495 indicate that these constituents were not 

significantly different at the respective confidence intervals. 

Results of paired tests between populations of Fe concentrations indicate that concentrations were significantly different 

only for Route 119 and Interstate 495, and results of paired 

tests between populations of Mn concentrations indicate 

concentrations were significantly different for Route 119 and 

Interstate 495, and for Route 119 and Interstate 95. Results of 

paired tests between populations of concentration data from 

Route 119 and each of the other principal highways indicate 

that dissolved Cl, Na, and Mg; benzyl n-butyl phthalate; and 

di-n-butyl phthalate were not significantly different at the 

respective confidence intervals. Although results of paired 

tests of concentrations of suspended sediment indicate a significant difference only for Route 119 (highway with the lowest 

AADT volume), results of tests were significant for concentrations of suspended sediment less than 0.063 mm in diameter in 

samples from Route 119 and Route 2. The significant difference between populations of concentrations of suspended sediment from Route 119 and the other principal highways may, 

in part, explain the significant difference between the populations of concentrations of sediment-associated constituents 

from the other principal highways. No significant difference 

was found for tests between populations of concentration data 

for Route 2 and Interstate 495, except for concentrations of 

sediment less than 0.063 mm in diameter. However, results of 

paired tests for populations of dissolved Ca and SO4

, total N, 

total-recoverable Cu, benzo[ghi]perylene, diethyl phthalate, 

indeno[1,2,3-cd]pyrene, and perylene concentrations between 

Route 2 and Interstate 95 indicate concentrations were significantly different a 95-percent confidence interval. Results of 

paired tests between populations of concentration data from 

Interstate 495 and Interstate 95 indicate concentrations were 

significantly different at a 95-percent confidence interval only 

for dissolved Ca, K, and SO4

; total N; and diethyl phthalate. 

Concentrations of dissolved Ca were significantly different 

for all paired tests on data from Interstate 95. The highwaymonitoring stations on Interstate 95 are located in a section of 

highway designated as a low-salt area because of the proximity to a major drinking-water source area; thus, the significant 

difference in concentrations of Ca for Interstate 95 are likely 

a function of more wide-spread use of liquid calcium chloride 

on that highway during the winter than on the other highways.

Relation of Constituents to Annual Average 

Daily Traffic

Because the principal highways share many similarities 

in construction, surrounding land use, and local soil composition, and because the samples of highway runoff were collected during similar storm and antecedent conditions, traffic 

volume was the most prominent factor distinguishing each 

highway and likely explains much of the observed difference 

in the data. The significant differences determined between 

populations of concentrations of data from Route 119, the 

highway with the lowest traffic volume, and populations of 

concentrations of data from the other principal highways are 

similar to findings from previous studies (Driscoll and others, 1990b) where an AADT volume of 30,000 vehicles was 

a noted breaking point for low and high concentrations of 

several constituents. Despite the similarities in highway design 

and land use among the four principal highways, few results of 

the Mann-Whitney tests between data sets for highways with 

AADT volumes greater than 30,000 vehicles per day (Route 2, 

Interstate 495, and Interstate 95) were significantly different at 

the 95-percent confidence interval.

The lack of test significance between populations of data 

for the principal highways with moderate or higher volumes 

of traffic (Route 2 and Interstates 495 and 95) could be a 

function of the finite capacity of a highway surface to entrain 

fine particulates as a result of roadway dispersion by vehicle 

turbulence. In controlled highway turbulence tests, more 

than 70 percent of marked particles 12 μm in diameter were 

removed from the highway surface within four passes of a 

passenger vehicle at 40 mi/h (Nicholson and Branson, 1990), 

and the percentage of particles removed from the highway 

surface increased with vehicle speed. The actual distance 

from the highway where resuspended particles deposit is 

largely a function of particle size; Gupta and others (1981) 

report that particles from 5 to 50 μm in diameter rapidly 

deposit near the highway right of way, and smaller particles 

deposit in places remote from the highway system. Most of 

the mass of particulate matter emitted in gasoline and diesel 

exhausts, and created from brake and tire wear, are reported to 

be less than 20 μm in diameter. For example, in two different 

standardized automotive tests, Cadle and others (2001) found 

that about 97 and 95 percent of the mass of particles emitted 

in exhaust from gasoline engines were less than 12.2 μm in 

diameter, and about 92 and 84 percent of the mass of particles were less than 1.2 μm in diameter. Councell and others 

(2004) report that mean tire-wear particles were between 10 

and 20 μm in diameter, and Garg and others (2000) report 

that from 63 to 86 percent of airborne particles from brake 

wear were less than 10 μm in diameter. These distributions 

of source-particle size indicate that a large quantity of the 

particles potentially are lost entirely from the highway system 

as a result of vehicle disturbance.

These factors may explain why populations of suspended-sediment concentrations were not significantly different (table 25) among the larger highways. In part, these factors 
70 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

also may explain some subtle similarities between concentration data from the principal highways. For example, the 

median and interquartile concentrations of several constituents 

(fig. 20) measured in composite samples of stormwater collected at the monitoring stations on Route 2 and Interstate 495 

were similar. Although the traffic density at the monitoring stations on Route 2 (about 9,920 vehicles per day per travel lane) 

was less than the traffic density at the monitoring stations on 

Interstate 495 (about 13,650 vehicles per day per travel lane), 

the posted speed limits were similar (55 and 65 mi/h, respectively), and traffic at both sites generally was free flowing. 

Consequently, the constant vehicle turbulence on the highways 

at these stations may have prevented a significantly dissimilar 

buildup of anthropogenic particles. In contrast, the differences between concentrations of the same constituents for 

Route 2 and Interstate 95, and Interstate 495 and Interstate 95, 

were greater than those between Route 2 and Interstate 495. 

Although the posted speed limit for Interstate 95 (55 mi/h) 

was similar to the posted speed limits for the Route 2 and 

Interstate 495, the traffic density per lane mile was about 94 

and 41 percent higher than the traffic density for Route 2 and 

Interstate 495, respectively. Consequently, Interstate 95 was 

generally more congested, and traffic movement often was 

slower, particularly during poor weather.

Although the populations of concentrations of most 

constituents were not significantly different among the three 

highways with higher AADT volumes, the median concentrations and upper interquartile ranges for many metals increased 

with increasing AADT volume (fig. 20), indicating a positive correlation between the two variables. The frequency of 

detection for various organic compounds also increased with 

the traffic volume on the principal highways (table 26). To 

further investigate the relation between concentration data 

and traffic volume, Kendall’s tau correlation coefficient and 

Spearman rank correlation coefficient tests (SAS Institute, 

1998) were performed to evaluate monotonic correlations 

between the median concentrations of selected constituents 

that were routinely detected at greater than the LTMDL and 

the AADT volume for each of the eight highways. Both tests 

are based on the ranks of the data and, therefore, are resistant 

to effects caused by outliers and are appropriate for use with 

censored values (Helsel and Hirsch, 2002). Each method 

provides results ranging from -1 (negative relation) through 

0 (no relation) to +1 (positive relation) (SAS Institute, 1998). 

Although the results for each test are similar, the test methods 

differ from each other. For example, differences between data 

values ranked farther apart are treated the same for Kendall tau 

test but receive more weight for the Spearman rank correlation 

coefficient test (Helsel and Hirsch, 2002).

The resultant test statistics and the respective p values 

for the Kendall’s Tau correlation coefficient and Spearman 

rank correlation coefficient tests are presented in table 27. Test 

results for one or both methods indicate that correlations of 

the median concentrations of total N, total P; all total-recoverable metals; benzo[a]anthracene, benzo[b]fluoranthene, 

fluoranthene, and pyrene with AADT volumes are significantly 

different at a 95-percent confidence interval. Spearman rank 

correlation coefficient test results for benzo[a]anthracene 

and benzo[b]fluoranthene were not significantly different at a 

95-percent confidence interval; however, correlations between 

the median concentrations of these constituents and the respective AADT volumes were significantly different at slightly 

lower confidence intervals. Test results for concentrations 

of dissolved Cl, Na, Ca, Mg, K, and SO4

; benzo[a]pyrene; 

bis(2-ethylhexyl) phthalate; chrysene; di-n-octyl phthalate; 

and suspended sediment were not significantly different at 

confidence intervals greater than 89 percent for either test; 

therefore, AADT volumes may be a poor predictor of concentrations of these constituents in the absence of additional data.

Estimated Concentrations of Major Constituents 

in Road Salt

Concentrations of Ca, Cl, Na, and SO4, which constitute 

the major constituents of road salt, were estimated on the basis 

of the superpositioning method and the event-mean values 

for specific conductance for all available data collected at 

11 highway-monitoring stations. Unfortunately, population 

statistics for the estimated concentrations of these major ions 

were not computed for runoff events at Route 8 because available data for non-winter storms were insufficient to model the 

transition from low-ionic strength runoff to runoff dominated 

by deicing compounds. Although the general statistics for the 

population of flow-weighted specific-conductance values were 

similar to that of the other highways sites, estimates for major 

ions could not accurately be made for 60 to 70 percent of the 

available data because of the disparity between ratios of Cl to 

the other major ions at the Route 8 station. Runoff quality in 

this area of the state may be different because the chemistry 

of precipitation in this area is different (National Atmospheric 

Deposition Program, 2008), and the composition of soils in 

this area is affected by weathering of limestone bedrock. Data 

for the other 11 monitoring stations were estimated for 1,381 

runoff events that include periods of measurable snowmelt 

(periods of runoff during the winter months with air temperatures greater than the freezing point and no records of measurable precipitation). These estimated concentration data provide 

an order of magnitude increase in data density over available 

water-sample data. Statistics for populations of estimated 

event-mean concentrations of selected constituents at all 

highways are listed in table 28. The median estimated concentrations of Cl ranged from about 10 to 40 mg/L for all highway 

sites, except for the site on Interstate 93 where the median 

estimated concentration was 79 mg/L. The median estimated 

concentrations of Cl were lowest for the monitoring stations 

on Route 119. Estimated concentrations of Ca, Na, and SO4

, 

which were derived from estimated concentrations of Cl, followed the same pattern. Estimated average concentrations for 

each constituent were substantially greater than the median 

estimated concentrations for each highway (table 28). This is a 

function of high right skew in the data populations caused by a 
Quality of Highway Runoff 71

Figure 20. Concentrations of selected constituents in samples of highway runoff collected at eight highway-monitoring 

stations in Massachusetts in relation to the annual average daily vehicles per travel lane.

LEAD

0.01

0.1

1

10

100

1,000

0.001

0.01

0.1

1

10

CADMIUM

0.01

0.1

1

10

NICKEL

0.1

1

10

100

1,000

CONCENTRATION, IN MICROGRAMS PER LITER

COPPER

(26) (5) (5) (28) (6) (28) (28) (5) (26) (5) (5) (28) (6) (28) (28) (5)

(26) (5) (5) (28) (6) (28) (28) (5) (26) (5) (5) (28) (6) (28) (28) (5) 1,500 (Route 119) 3,880 (Route 8) 6,400 (Interstate 195) 9,920 (Route 2) 10,290 (Interstate 190) 13,650 (Interstate 495) 19,310 (Interstate 95) 23,870 (Interstate 93) 1,500 (Route 119) 3,880 (Route 8) 6,400 (Interstate 195) 9,920 (Route 2) 10,290 (Interstate 190) 13,650 (Interstate 495) 19,310 (Interstate 95) 23,870 (Interstate 93)

 ANNUAL AVERAGE VEHICLES PER DAY PER TRAVEL LANE

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION

Mean

(26) Number of observations
72 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 26. Frequency of detection for selected polyaromatic hydrocarbons and phthalate compounds in composite samples of 

highway runoff collected from the four principal highways at eight sites in Massachusetts, 2005–07.

[LTMDL, long-term method detection level; ≥, greater than or equal to LTMDL]

Compound

Frequency of detection (percent) Frequency of detection (percent ≥ LTMDL)

Route 119 Route 2 Interstate 

495

Interstate 

95 Route 119 Route 2 Interstate 495

Interstate 

95

Fluorene 38 67 68 46 0 0 7 7

Acenaphthene 27 44 50 43 0 0 11 11

Acenaphthylene 31 48 50 46 0 0 4 0

Anthracene 35 59 86 86 0 0 11 21

Benzo[a]anthracene 38 85 96 96 12 52 54 71

Benzo[a]pyrene 62 89 93 100 23 56 50 68

Benzo[b]fluoranthene 69 96 100 100 31 70 68 82

Benzo[ghi]perylene 77 85 89 93 8 19 29 43

Benzo[k]fluoranthene 50 89 96 100 4 30 32 46

Benzyl n-butyl phthalate 8 19 18 32 8 11 14 25

Bis(2-ethylhexyl) phthalate (DEHP) 50 85 79 82 50 85 79 82

Chrysene 62 85 100 100 27 59 61 75

Dibenzo[a,h]anthracene 4 22 32 36 0 0 0 4

Diethyl phthalate (DEP) 19 19 7 21 4 4 4 14

Dimethyl phthalate 12 22 18 25 0 0 0 0

Di-n-butyl phthalate 27 41 39 36 15 15 21 29

Di-n-octyl phthalate 54 93 75 86 19 74 61 75

Fluoranthene 88 100 100 100 38 81 82 86

Indeno[1,2,3-cd]pyrene 69 93 89 93 4 22 32 43

Nitrobenzene 4 7 14 0 0 0 0 0

Phenanthrene 85 96 100 96 23 52 46 61

Pyrene 88 100 100 100 31 70 71 82

Naphthalene 19 44 39 54 0 0 7 4

Perylene 12 67 64 68 0 0 18 35
Quality of Highway Runoff 73

Table 27. Resultant test and p values for Kendall Tau and Spearman Rank correlation tests performed on median values of populations 

of constituent concentrations in highway runoff and annual average daily traffic volumes for the principal highways in Massachusetts, 

2005–07.

[Shaded areas indicate values that are significant at a 95-percent confidence interval]

Constituent Kendall Tau value Kendall Tau p value Spearman Rho value Spearman Rho p value

Chloride 0.357 0.216 0.405 0.284

Sodium 0.429 0.138 0.429 0.257

Calcium 0.286 0.322 0.238 0.529

Magnesium 0.429 0.138 0.310 0.413

Potassium 0.429 0.138 0.595 0.115

Sulfate 0.500 0.083 0.595 0.115

Nitrogen, total 0.857 0.003 0.952 0.012

Phosphorus, total 0.714 0.013 0.857 0.023

Cadmium 0.929 0.001 0.976 0.010

Chromium 0.714 0.013 0.881 0.020

Copper 0.929 0.001 0.976 0.010

Iron 0.786 0.007 0.857 0.023

Lead 0.786 0.007 0.881 0.020

Manganese 0.679 0.019 0.804 0.034

Nickel 0.786 0.007 0.905 0.017

Zinc 0.786 0.007 0.857 0.023

Benzo[a]anthracene 1.000 0.042 1.000 0.083

Benzo[a]pyrene 0.667 0.174 0.800 0.166

Benzo[b]fluoranthene 0.800 0.050 0.900 0.072

Bis(2-ethylhexyl) phthalate 0.333 0.348 0.486 0.277

Chrysene 0.667 0.174 0.800 0.166

Di-n-octyl phthalate 0.429 0.177 0.643 0.115

Fluoranthene 0.867 0.015 0.943 0.035

Pyrene 0.867 0.015 0.943 0.035

Suspended sediment 0.357 0.216 0.476 0.208
74 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 28. Selected statistics for populations of concentrations of chloride, sodium, calcium, and sulfate estimated from event-mean 

values of specific conductance calculated from continuous measurements of flow and specific conductance for the period of record 

for 11 highway monitoring stations in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey]

USGS station 

number Highway Number of events Statistic Chloride Sodium Calcium Sulfate

424209071545201 Route 119 149 Maximum 4,500 2,600 65 140

Median 18 13 2.7 3.4

Average 285 168 7.8 14

Standard deviation 818 473 13 28

Skew 3.76 3.76 2.86 3.10

Minimum 1.1 0.87 0.44 0.45

424155071543201 Route 119 105 Maximum 3,100 1,800 53 110

Median 10 7.6 1.9 2.3

Average 96 58 4.2 6.6

Standard deviation 359 208 7.3 14

Skew 6.72 6.72 4.29 4.99

Minimum 1.1 0.91 0.45 0.46

423027071291301 Route 2 148 Maximum 11,000 6,100 100 240

Median 36 25 4.0 5.4

Average 542 315 11 21

Standard deviation 1,510 860 19 41

Skew 3.98 3.87 2.67 2.96

Minimum 1.8 1.4 0.62 0.65

423027071291302 Route 2 72 Maximum 25,000 14,000 170 420

Median 32 22 3.8 5.0

Average 1,070 612 14 28

Standard deviation 4,040 2,276 31 74

Skew 4.69 4.65 3.80 4.05

Minimum 3.2 2.5 0.90 0.99

422821071332001 Interstate 495 178 Maximum 20,000 11,000 150 360

Median 29 20 3.6 4.7

Average 543 315 11 20

Standard deviation 2,000 1,130 20 44

Skew 7.08 6.86 3.91 4.56

Minimum 1.6 1.3 0.57 0.59

422716071343901 Interstate 495 115 Maximum 14,000 7,800 120 280

Median 37 25 4.1 5.5

Average 834 478 14 27

Standard deviation 2,400 1,350 25 56

Skew 3.83 3.76 2.73 2.98

Minimum 0.58 0.48 0.29 0.28
Quality of Highway Runoff 75

Table 28. Selected statistics for populations of concentrations of chloride, sodium, calcium, and sulfate estimated from event-mean 

values of specific conductance calculated from continuous measurements of flow and specific conductance for the period of record 

for 11 highway monitoring stations in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey]

USGS station 

number Highway Number of events Statistic Chloride Sodium Calcium Sulfate

422620071153301 Interstate 95 126 Maximum 10,000 5,800 100 230

Median 40 27 4.3 5.9

Average 441 258 11 19

Standard deviation 1,320 761 17 36

Skew 5.07 5.09 3.14 3.62

Minimum 0.48 0.40 0.25 0.24

422420071153302 Interstate 95 103 Maximum 12,000 6,900 110 260

Median 26 18 3.3 4.3

Average 526 306 11 20

Standard deviation 1,630 935 19 42

Skew 4.69 4.69 3.03 3.40

Minimum 0.58 0.48 0.29 0.28

423016071431501 Interstate 190 138 Maximum 22,000 13,000 160 390

Median 24 17 3.1 4.1

Average 1,340 778 18 37

Standard deviation 3,710 2,150 32 76

Skew 3.57 3.60 2.59 2.85

Minimum 1.2 0.99 0.48 0.49

414339070462201 Interstate 195 125 Maximum 8,500 4,900 92 210

Median 22 15 3.0 3.8

Average 478 278 11 20

Standard deviation 1,280 732 18 37

Skew 3.85 3.87 2.55 2.86

Minimum 1.6 1.2 0.57 0.59

421647071024703 Interstate 93 122 Maximum 21,000 12,000 150 380

Median 79 52 6.4 9.3

Average 897 521 16 31

Standard deviation 2,510 1,430 24 55

Skew 5.43 5.40 2.86 3.46

Minimum 7.4 5.5 1.5 1.8

All sites -- 1381 Maximum 25,000 14,000 170 420

Median 29 20 3.5 4.7

Average 627 364 12 22

Standard deviation 2,160 1,240 21 49

Skew 6.06 6.02 3.50 4.05

Minimum 0.5 0.4 0.3 0.2
76 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

relatively small number of high estimated concentrations. For 

example, the percentage for all estimated concentrations of Cl 

greater than 10,000 mg/L was less than 2 percent (fig. 21), and 

the percentage for all estimated concentrations of Cl greater 

than 230 mg/L (the USEPA national recommended freshwaterquality criteria; U.S. Environmental Protection Agency, 2009) 

was about 20 percent (fig. 21). The highest EMCs of deicing 

compounds were typically measured for mixed precipitation 

storms, which usually generate only small flows, for small 

rain storms that occur subsequent to applications of deicing 

compounds, and for relatively small amounts of snowmelt 

water. Thus, Cl yields per lane mile may be more useful for 

estimating the potential effects on receiving water quality. 

The frequency at which a given yield of Cl per lane mile was 

equaled or exceeded is illustrated in figure 22. If the average 

background in-storm concentration of Cl and volume of flow 

corresponding to the runoff event for the receiving water body 

are known, and the area of highway draining directly to the 

water body can be calculated, the data illustrated in figure 22 

can be used to determine the potential risk for exceeding some 

threshold concentration of Cl in the receiving water body during the runoff event.

Evaluation of Constituents in Seasonal Samples 

of Runoff from the Principal Highways

The concentrations of constituents in samples of highway 

runoff varied considerably from storm to storm, as well as 

from station to station. However, concentrations of nearly all 

constituents measured in composite samples of highway runoff 

collected after the first snowfall in January 2006 through April 

2006, and March 2007 through April 2007, increased substantially during the winter months. The average concentrations 

of total P, total-recoverable metals, and suspended sediment in 

samples of highway runoff collected during the winter were 

about 3 to 11 times the average concentrations observed in 

samples of non-winter runoff (table 29). Concentrations of 

suspended sediment and majors ions are expected to increase 

during the winter season in Massachusetts as a result of the 

application of deicing compounds and maintenance sands to 

the highway surface; however, virtually all populations of winter and non-winter concentrations of metals, PAH compounds, 

and phthalates also increased substantially. Changes in ambient temperature, differences in driving methods, snow-removal 

operations, and the presence of snow embankments along the 

highways also affect the winter concentrations of metals and 

Figure 21. Percentage of event-mean concentrations of chloride estimated from continuous 

records of specific conductance for 1,381 runoff events from 11 highway-monitoring stations on 

7 highways in Massachusetts to measured concentrations of chloride in composite samples of 

highway runoff.

0.1

1

10

100

1,000

10,000

100,000

CHLORIDE CONCENTRATION, IN MILLIGRAMS PER LITER

PERCENTAGE OF ESTIMATED EVENT-MEAN CONCENTRATIONS OF CHLORIDE IN 

WHICH EVENT-MEAN SPECIFIC CONDUCTANCE WAS EQUALED OR EXCEEDED 

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.5 99.9 99.99
Quality of Highway Runoff 77

10 -5

10 -4

10 -3

10 -2

10 -1

10 0

10 1

10 2

10 3

10 4

10 5

ESTIMATED CHLORIDE YIELD, IN POUNDS PER LANE MILE

PERCENTAGE OF ESTIMATED CHLORIDE YIELD IN WHICH THE YIELD WAS EQUALED OR EXCEEDED

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.5 99.9 99.99

Figure 22. Probability distribution for loads of chloride estimated from continuous records of specific 

conductance for 1,381 runoff events from 11 highway-monitoring stations on 7 highways in Massachusetts.

Table 29. The ratio of mean concentrations of total nutrients, total-recoverable metals, and suspended sediment in composite 

samples of highway runoff collected during winter storms to mean concentrations of the respective constituents in samples collected 

during non-winter storms for the primary and secondary stations on four principal highways in Massachusetts, 2005–07.

Highway Nitrogen Phosphorus Cadmium Chromium Copper Iron

Route 119 1.5 3.9 5.0 5.8 4.4 14.4

Route 2 1.1 2.4 6.6 2.9 3.1 6.8

Interstate 495 1.4 3.7 6.3 4.0 4.0 8.2

Interstate 95 1.6 2.4 11.4 3.5 3.3 6.9

Highway Lead Manganese Nickel Zinc Suspended

sediment

Route 119 11.4 6.6 6.9 6.0 11.6

Route 2 5.5 4.9 7.1 3.8 3.1

Interstate 495 7.9 6.4 6.1 4.3 9.1

Interstate 95 4.2 6.0 5.4 4.3 5.8
78 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

organic compounds measured in this study. Results of singletail Mann-Whitney tests indicate that the concentrations of 

nearly all constituents measured in samples of highway runoff 

collected during the winter and after the first snowfall from 

each principal highway were significantly greater at a 99-percent confidence interval (p value less than 0.01; table 30).

Deicing compounds are not entirely pure and thus contain 

trace amounts of elements typically associated with highway 

runoff; however, the trace amounts of total N and total-recoverable metals in highway deicing compounds do not fully 

explain the significant differences in concentrations observed 

during winter. Ratios for concentrations of nitrate and totalrecoverable Cr, Cu, Fe, Pb, and Ni to concentrations of Cl 

in samples of Massachusetts road salt reported by Granato 

(1996) and in a sample of liquid calcium chloride (table 31) 

collected at the Lexington, Massachusetts, DOT maintenance 

depot ranged from 10-5 to 10-6. At a ratio of 10-5 for nitrate and 

Fe to Cl, the estimated increase in the EMC for these constituents, resulting from the addition of deicing compounds 

at a Cl concentration of 10,000 mg/L (which occurred in less 

than 2 percent of all of the runoff events during the 2.5-year 

monitoring period; fig. 21), is about 0.1 mg/L. In contrast, 

the difference between the mean non-winter and mean winter 

concentrations of nitrate and Fe in composite samples of 

runoff was many times larger. For example, the differences 

between the mean non-winter and winter concentrations for 

total N and total-recoverable Fe in composites of highway 

runoff collected at the monitoring stations on Interstate 495 

are about 0.45 and 14.4 mg/L, respectively. For the same 

EMC of Cl and using a ratio of 10-6 for total-recoverable Cr, 

Cu, and Pb to Cl, the estimated increase in the EMC, resulting from the addition of deicing compounds, is about 10 μg/L. 

In contrast, the differences between the mean non-winter and 

winter concentrations for these same constituents in composite 

samples of runoff collected at the monitoring stations on Interstate 495 are about 27.8, 85.4, and 49.4 μg/L, respectively. At 

more typical Cl concentrations of about 1,000 mg/L (which 

occurred in less than 12 percent of all of the storms during 

the 2.5-year monitoring period; fig. 21), the concentrations of 

nitrate and the total-recoverable metals would decrease by an 

order of magnitude. These levels represent less than 4 percent 

of the mean increase in EMCs for the respective constituents 

measured in composite samples of highway runoff collected 

during the winter at the monitoring stations on Interstate 

495. Although the ratios of winter to non-winter concentrations of total-recoverable Cr, Cu, and Pb are somewhat 

similar from highway to highway (table 29), road salt could 

account, in part, for the larger increases in concentrations of 

the respective elements during winter for smaller highways, 

such as Route 119, because the non-winter concentrations of 

the metals are lower than the non-winter concentrations for 

the other principal highways. For example, the differences 

between the mean non-winter and winter concentrations of 

total-recoverable Cr, Cu, and Pb at the monitoring stations on 

Route 119 are about 11.9, 18, and 17 μg/L, respectively. At 

Cl concentrations of about 1,000 mg/L, the concentration of 

the three total-recoverable metals associated with the deicing 

compounds represent about 8 to 6 percent, respectively, of 

the mean increase in the EMC for the respective constituents 

measured in composite samples of highway runoff collected at 

the Route 119 monitoring stations.

The increase in concentrations of total P and total-recoverable metals during winter also are associated with the application of maintenance sand. Highway maintenance sand is a 

hard material, free of organic material, with no melting capabilities. Winter maintenance sands are applied to the highway 

to increase tire traction on the pavement. Maintenance sand, 

like soils, contains trace amounts of total P and total-recoverable metals. Although the concentrations of these constituents in the sand are small, the amount of sand applied to the 

highways during the winter can increase the concentration of 

suspended sediment by as much as an order of magnitude. For 

example, the ratios of mean non-winter EMCs of suspended 

sediment to mean winter EMCs in samples collected at the 

monitoring stations on the principal highways ranged from 3.1 

to 11.6 (table 29). An approximate contribution of total P and 

total-recoverable metals from the application of maintenance 

sand was estimated on the basis of the average change in the 

concentration of suspended sediment during winter storms 

and on the basis of the mean concentrations of the associated 

constituents in samples of highway maintenance sand (table 18 

in the back of the report). For example, the average increase 

in the EMC of suspended sediment in composite samples 

of runoff collected during winter storms at the monitoring 

stations on Interstate 495 was about 637 mg/L. Assuming 

that the increase in the concentration of suspended sediment 

is exclusively accounted for by the addition of maintenance 

sand, the estimated concentrations for total P, and total-recoverable Cu, Fe, Mn, Ni, Pb, and Zn associated with the sand are 

about 0.24 mg/L and 5.7, 7, 640, 134, 5.3, 4.3, and 10.1 μg/L, 

respectively. After further adjusting the estimated concentrations of P, Fe, Ni, and Zn on the basis of the performance of 

the different analytical digestion methods discussed earlier, 

highway maintenance sand would account for about 94, 7, 38, 

53, 15, 9, and 2 percent of the increase in winter EMCs for 

P, Cu, Fe, Mn, Ni, Pb, and Zn, respectively. As noted earlier, 

the differences between winter and non-winter EMCs for P, 

Cu, Fe, Mn, Ni, Pb, and Zn are greater for smaller highways 

because those highways have lower non-winter EMCs for 

these constituents (table 29).

The Mass DOT typically uses salt alone, but also applies 

maintenance sand to the highway as a 1-to-1 sand-to-salt 

premix at low temperatures and on roadway sections with 

steep grades, ramp sections, sharp curves, and at intersections (Massachusetts Department of Transportation, 2006). 

Routine application of maintenance sand is limited to reduced 

salt zones, such as Interstate 95 in this study (Massachusetts Department of Transportation, 2008). However, Mass 

DOT records indicate that maintenance sand was applied 

to a greater extent on Massachusetts highways during this 

study (Paul Brown, Massachusetts Department of Transportation, written commun., 2010). As a result, concentrations for 
Quality of Highway Runoff 79

Table 30. Resultant p values for single-tail Mann-Whitney tests between paired populations of winter and non-winter concentrations 

of constituents in highway runoff collected from the primary and secondary stations on the four principal highways in Massachusetts, 

2005–07.

[<, Less than value shown; --, insufficient detections to perform test; mm, millimeters in diameter; shaded areas indicate values that are significant at a 99-percent confidence interval]

Constituent Route 119 Route 2 Interstate 495 Interstate 95

Chloride <0.001 <0.001 <0.001 <0.001

Sodium <0.001 <0.001 <0.001 <0.001

Calcium <0.001 <0.001 <0.001 <0.001

Magnesium <0.001 <0.001 <0.001 <0.001

Potassium <0.001 <0.001 <0.001 <0.001

Sulfate <0.001 <0.001 <0.001 <0.001

Nitrogen, total 0.011 0.084 0.017 0.013

Phosphorus, total <0.001 0.001 <0.001 0.001

Cadmium <0.001 <0.001 0.014 <0.001

Chromium <0.001 <0.001 <0.001 <0.001

Copper <0.001 <0.001 <0.001 <0.001

Iron <0.001 <0.001 <0.001 <0.001

Lead <0.001 <0.001 <0.001 <0.001

Manganese <0.001 <0.001 <0.001 <0.001

Nickel <0.001 <0.001 <0.001 <0.001

Zinc <0.001 <0.001 <0.001 <0.001

Fluorene -- -- -- --

Acenaphthene -- -- -- --

Acenaphthylene -- -- -- --

Anthracene -- -- -- --

Benzo[a]anthracene -- <0.001 <0.001 <0.001

Benzo[a]pyrene -- <0.001 <0.001 <0.001

Benzo[b]fluoranthene <0.001 <0.001 <0.001 <0.001

Benzo[ghi]perylene -- 0.002 0.001 <0.001

Benzo[k]fluoranthene -- <0.001 <0.001 <0.001

Benzyl n-butyl phthalate -- -- 0.003 0.003

Bis(2-ethylhexyl) phthalate 0.002 <0.001 <0.001 <0.001

Chrysene <0.001 <0.001 <0.001 <0.001

Dibenzo[a,h]anthracene -- -- -- --

Diethyl phthalate -- -- -- 0.162

Dimethyl phthalate -- -- -- --

Di-n-butyl phthalate 0.203 -- -- 0.008

Di-n-octyl phthalate <0.001 <0.001 <0.001 0.005

Fluoranthene -- <0.001 <0.001 <0.001

Indeno[1,2,3-cd]pyrene -- <0.001 <0.001 <0.001

Nitrobenzene -- <0.001 -- --

Phenanthrene <0.001 <0.001 <0.001 <0.001

Pyrene <0.001 <0.001 <0.001 <0.001

Naphthalene -- -- -- --

Perylene -- -- <0.001 <0.001

Suspended sediment <0.001 0.001 <0.001 <0.001

Suspended sediment < 0.063 mm 0.384 <0.001 0.017 0.003
80 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 31. Concentrations of selected constituents measured in a sample of liquid calcium chloride collected at the highwayservice depot near Interstate 95, Lexington, Massachusetts and diluted to 3.5 percent by mass and the ratio of the concentration of 

each constituent to the concentration of chloride.

[μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; <, concentration is less than value 

shown; E, the concentration reported is less than laboratory reporting level and is qualified as estimated; --, no information]

Constituent Concentration or

measurement

Ratio of

constituent concentration to 

chloride concentration

pH in standard units 10.0 --

Specific conductance in μS/cm 19,600 --

Calcium, filtered, mg/L 3,640 4.98 × 10-1

Magnesium, filtered, mg/L 0.26 3.56 × 10-5

Potassium, filtered, mg/L 150 2.05 × 10-2

Sodium, filtered, mg/L 85.9 1.18 × 10-2

Alkalinity, filtered, laboratory, mg/L as calcium carbonate 28 --

Chloride, filtered, mg/L 7,310 1.00

Sulfate, filtered, mg/L <4.5 <6.16 × 10-4

Total nitrogen (nitrate + nitrite + ammonia + organic-N), unfiltered, mg/L 0.17 2.33 × 10-5

Phosphorus, unfiltered, mg/L <.02 <2.74 × 10-6

Arsenic, unfiltered, mg/L E2.5 3.42 × 10-4

Barium, unfiltered, μg/L 210 2.78 × 10-2

Cadmium, unfiltered, μg/L E0.11 1.50 × 10-5

Chromium, unfiltered, μg/L <3.2 <4.38 × 10-4

Copper, unfiltered, μg/L <9.6 <1.31 × 10-3

Iron, unfiltered, μg/L E84 1.15 × 10-2

Lead, unfiltered, μg/L 0.3 4.10 × 10-5

Manganese, unfiltered, μg/L <6.4 <8.76 × 10-4

Nickel, unfiltered, μg/L 0.96 1.31 × 10-4

Selenium, unfiltered, μg/L <0.6 <8.21 × 10-5

Zinc, unfiltered, μg/L 16 2.19 × 10-3

Total organic carbon, mg/L <0.4 <5.47 × 10-5
Comparison of Historical and Concurrent Data Sets 81

suspended sediment and other constituents associated with 

highway maintenance sands in composite samples collected 

during winter storms in this study (except for samples collected at the primary and secondary stations of Interstate 95 

and the test station on Interstate 195) may represent higher 

values in regard to the 2008 sanding policy.

Changes in ambient temperature affect the rate of emissions for both gasoline and diesel engines. In controlled tests, 

Westerholm and Egebäck (1994) reported that the mean 

emission rates for particulate matter and oxides of nitrogen 

for five gasoline-powered vehicles increased by a factor of 

two between tests conducted at 22 and -10o

C, and total PAHs 

increased by about a factor of five. In a larger scale test, Cadle 

and others (2001) noted that particulate matter increased by a 

factor of 2.5 between tests conducted at mean temperatures of 

15.5 and 3.3o

C. Increases in the rate of emissions from diesel 

vehicles during winter operation also have been reported 

(Kuusimaki, 2003). The rate of vehicle emission, as well as 

brake and tire wear, can increase during poor winter driving 

conditions when vehicle speeds are slower and less constant. 

Inconsistent regulation of the engine speed results in temporary fuel enrichment that potentially increases emission rates. 

Colder winter temperatures also affect the rate of volatilization 

and bacterial degradation for PAHs and phthalates (Lopes and 

Dionne, 1998). These factors also contribute to the increase 

in concentrations of total N, total-recoverable metals (except 

for Mn, which may have a greater association with sanding 

or road wear), PAHs, and phthalates observed in samples collected during winter.

One final factor that could explain, in part, the increase 

in concentrations of total P, total-recoverable metals, PAH, 

and phthalates between winter and non-winter samples is the 

effect of snow removal from the roadway. Snow is generally 

removed from the highway with heavy trucks equipped with 

plows, and in some cases, tire chains. This results in contact 

wear of both the equipment and the roadway surface. Snowplows and tire chains are constructed predominantly from Fe 

or Fe alloys. In contrast, Mn and Zn are the dominant metals found in asphalt with lesser amounts of Cr, Fe, Pb, and 

Ni (Breault and others, 2005). Asphalt also contains several 

PAH compounds, such as benzo[b]fluoranthene, chrysene, and 

phenanthrene. Increases in concentrations of Fe, Mn, Zn, and 

the above PAHs during winter could result, in part, from the 

wear of these contact surfaces. Another effect of snow plowing 

is the tendency for snow to pack into the openings of highway guardrails. Such snow packs effectively form large curbs 

that can be as high as or higher than the guardrails (fig. 23). 

In such cases, not only do solids build up near the base of 

the pack, but the snow pack itself absorbs large amounts of 

particulates that subsequently are deposited on or near the 

highway shoulder after the snow melts. Glenn and Sansalone 

(2002) found that various highway-related constituents accumulated in fresh snow banks quickly during the first 12 hours 

after plowing, and Reinosdotter and others (2006) report that 

in snow surveys done perpendicular to highways, most of the 

highway-related metals were present in the first few horizontal 

feet of highway snow banks. Because most of the monitoring 

stations in the study have guardrails within the highway-drainage areas, deposition of particulates near or on the highway 

shoulder from melting snow packs also is an important factor 

that may explain some of the significant differences in concentrations of the constituents measured in this study between 

non-winter and winter storms.

Comparison of Historical and 

Concurrent Data Sets

Highway managers and other data analysts need current 

data to accurately estimate loads of various constituents discharged from highways and to determine the effects of these 

loads on receiving water bodies. The accuracy of information 

on constituent loads is ensured, in part, by periodically collecting new data. Comparisons of the data collected in this study 

with other subsequent data can provide useful information for 

identifying compositional differences and trends in highway 

runoff. Such differences can result over time from changes 

in anthropogenic sources, sampling methods, and laboratory 

analytical methods. Differences in the composition of highway 

runoff also are affected by local materials that are deposited 

on the highways in different geographic areas. Populations of 

constituent concentrations, separated by either time or space, 

that are similar can be combined to form a robust data set. In 

contrast, it is inappropriate to combine populations of constituents that exhibit large but potentially explainable differences, 

and at best, the data sets are periodically updated to monitor 

trends in the concentrations so that future analyses will be 

accurate.

From 1985 to 2009, automobile technology, tire and 

brake-pad formulations, fuel additives, construction materials, 

and highway maintenance practices have changed. Methods 

used for sample collection, handling, and analysis of environmental samples have improved since the early 1980s. As 

a result, the laboratory analytical techniques have improved 

the accuracy and precision of analysis and the detection of 

contaminants in stormwater runoff (Van Loon, 1985; Thompson and Walsh, 1989; Garbarino and Struzeski, 1998). To 

determine the potential effect of these changes, the median 

concentrations of dissolved Cl, total N and P, and total-recoverable Cd, Cr, Cu, Fe, Pb, and Zn in all data sets collected for 

Interstate 190, Interstate 195, Interstate 495, and Route 2 were 

compared to the median concentrations recorded in historical highway-runoff data sets (Driscoll and others, 1990a) 

collected by eight other states from 1976 to 1984 at highway 

sites with similar AADT volumes of 30,000 to 85,000 vehicles 

per day (table 32). The 90-percent confidence interval was 

computed for the median value of each constituent using the 

methods described by McGill and others (1978). With the 

exception of dissolved Cl, the median concentrations of the 

nutrients and metals in this study were less than the median 

concentrations in the historical data. Furthermore, the median 
82 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 23. A snow bank along the guard rail near the highway-monitoring station on Route 119, in Ashburnham, Massachusetts.
Comparison of Historical and Concurrent Data Sets 83

Table 32. Median of event-mean concentrations and 90-percent confidence interval for selected constituents in samples of highway 

runoff collected during this study, historical highway studies, and other recent studies for highways with annual average daily traffic 

volumes of 30,000 to 85,000 vehicles.

[CI, 90-percent confidence interval for median; mg/L, milligrams per liter; μg/L, micrograms per liter; AR, Arizona; CA, California; MA; Massachusetts; MN, 

Minnesota; NC, North Carolina; PA, Pennsylvania; TN, Tennessee; TX, Texas; WA, Washington; WI, Wisconsin; --, no data]

State where data 

were

collected

Data

collection 

period

(years)

Statistic

Constituent

Chloride

(mg/L)

Total

nitrogen

(mg/L)

Total

Phosphorus

(mg/L)

Total

recoverable 

cadmium

(μg/L)

Total

recoverable 

chromium

(μg/L)

MA 2005–07 Median 17.6 1.09 0.11 0.175 11

CI 10.8 0.21 0.03 0.07 2.4

Samples 67 67 67 67 67

Sites 4 4 4 4 4

AR, CA, MN,

NC, PA, TN,

WA, WI

1976–84 Median 17.5 2.64 0.37 20 20

CI 8.37 0.63 0.06 5.06 6.8

Samples 270 56 262 116 115

Sites 10 4 10 6 5

CA 1999–2003 Median 490 -- 0.22 0.45 5.5

CI 55 -- 0.03 0.07 0.74

Samples 17 -- 242 225 225

Sites 1 -- 14 13 14

WA 1994–97 Median -- -- 0.11 0.46 --

CI -- -- 0.03 0.23 --

Samples -- -- 57 31 --

Sites -- -- 4 4 --

TX 1994–97 Median -- -- 0.22 -- --

CI -- -- 0.03 -- --

Samples -- -- 102 -- --

Sites -- -- 3 -- --
84 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 32. Median of event-mean concentrations and 90-percent confidence interval for selected constituents in samples of highway 

runoff collected during this study, historical highway studies, and other recent studies for highways with annual average daily traffic 

volumes of 30,000 to 85,000 vehicles.—Continued

[CI, 90-percent confidence interval for median; mg/L, milligrams per liter; μg/L, micrograms per liter; AR, Arizona; CA, California; MA; Massachusetts; MN, 

Minnesota; NC, North Carolina; PA, Pennsylvania; TN, Tennessee; TX, Texas; WA, Washington; WI, Wisconsin; --, no data]

State where 

data were collectedStatistic

Constituent

Data source

Total

recoverable 

copper

(μg/L)

Total

recoverable

iron

(μg/L)

Total

recoverable

lead

(μg/L)

Total

recoverable

Zinc

(μg/L)

MA Median 25.5 1,690 8 166 This study

CI 8.5 677 2.4 53.5

Samples 67 67 67 67

Sites 4 4 4 4

AR, CA, MN, 

NC, PA, TN, 

WA, WI

Median 55 5,800 400 300 Driscoll and others, 1990a

CI 8.3 848 67.1 32.25

Samples 289 154 319 210

Sites 10 6 11 9

CA Median 22 2,930 6.05 105.5 Californa Department of Transportation 

Office of Environmental Engineering, 2000, 2002, 2003a, 2003b, 2003c, 

2003d, 2004

CI 2.57 2,525 1.72 15.0

Samples 242 39 242 242

Sites 14 3 14 14

WA Median 20 -- 10 120 Taylor Associates, Inc., 2002a, 2002b; 

Tetra Tech, Inc. and Envirovision Corporation, 2002; Tetra Tech, Inc. 2003, 

2004; Washington State Department of 

Transportation, Environmental Services 

Office, 2001, 2002, 2003, 2004

CI 5.53 -- 2.93 30.05

Samples 57 -- 31 57

Sites 4 -- 4 30.05

TX Median 11 1,500 49 101 Barrett and others, 1995, 1996; Walsh and 

others, 1997 CI 4.81 448 18.24 31.17

Samples 84 87 82 94

Sites 3 3 3 3
Sources of Highway-Runoff Constituents 85

historical concentrations for these constituents were outside 

the 90-percent confidence interval determined for this study, 

indicating there is a significant difference between data sets. 

Although the median concentrations for dissolved Cl were 

quite similar between the study and historical data sets, the 

differences for other constituents were often substantial. For 

example, the median concentrations for total-recoverable Cd 

and Pb for this study were 114 and 50 times lower, respectively, than the historical median concentrations. These data 

indicate that concentrations of nutrients and metals in highway runoff, particularly Cd and Pb, are substantially lower in 

this study than in the 1970s and 1980s, despite the fact that 

total vehicle miles have increased (Colman and others, 2001; 

Breault and Granato, 2000). These differences are likely attributable, at least in part, to improvements in fuel formulations, 

emission control systems, and tire life.

As discussed earlier, large differences in the composition of wash-on materials (adjacent soils and berm materials) 

and differences in the amount of impervious area surrounding the highway can potentially cause significant differences 

between the data populations. However, it is not logistically 

or economically feasible to collect data for every storm and 

on every highway. As a result, population statistics are limited 

by the number of samples, and data are often extrapolated to 

highways that do not necessarily share all of the characteristics 

of the highway where the data were originally collected. With 

this in mind, it is often beneficial to systematically combine 

smaller data sets to form more robust data populations. The 

median concentrations of dissolved Cl, total P, and total-recoverable Cd, Cr, Cu, Fe, Pb, and Zn from all data collected from 

Interstate 190, Interstate 195, Interstate 495, and Route 2 were 

compared to available median concentrations of the respective constituents for highway with AADT volumes of 30,000 

to 85,000 vehicles per day to determine whether data collected in other recent studies are similar to the data presented 

in this study (table 32). The previous studies were conducted 

between 1994 and 2003 in California, Texas, and Washington. 

Concentration data for Cl was available for only one station 

near Lake Tahoe in California, and most of the samples were 

collected during the winter months (California Department 

of Transportation, Office of Environmental Engineering, 

2003a-d), thus explaining the larger median concentration of 

Cl compared to the median concentration in this study. The 

median concentration of 0.11 mg/L for total P in this study 

is identical to the median concentration reported for the state 

of Washington but is about half of the median concentration 

for the California and Texas studies (table 32). The median 

concentration of Cr for this study is higher than the median 

concentration for the California data set, and the 90-percent 

confidence intervals do not overlap. Median concentrations 

for Cu and Pb for this study are similar to the median concentrations in the California and Washington studies, but the 

90-percent confidence intervals for this study and the Texas 

data set do not overlap. The 90-percent confidence intervals 

for the median concentrations of Fe and Zn overlap for all four 

studies. The similarities in many of these populations selected 

on the basis of AADT volumes indicate that some recent data 

collected in states other than Massachusetts could supplement 

the data collected in this study.

Sources of Highway-Runoff 

Constituents

Highway runoff is a complex mix of contaminants from 

multiple sources that include automobile and highway residuals, atmospheric deposition, local soils, highway-berm soil, 

highway-maintenance materials, and other sources. Antecedent conditions, traffic volume, climate, storm characteristics, 

and other factors also can affect the quality of highway runoff. 

Identification of individual sources of specific constituents 

is difficult because many highway-related constituents are 

found in a wide variety of natural and anthropogenic materials deposited on highways. For example, Zn is found in soil 

(table 19 in the back of the report), berm materials (table 20 

in the back of the report), highway guardrails, automobile 

components, automobile emissions, tire particles, brake dust, 

automobile lubricants, and atmospheric deposition. Accurate 

assessments of yields of specific constituents are further complicated by differences in exhaust emissions rates, and brake 

and tire wear rates, which are a function of road conditions 

and traffic density.

Common Highway Constituents

Principal component analysis was used for dimensional 

reduction of the data. In general, principal component techniques are used to identify underlying data structures by 

establishing linear combinations of the p original variables, 

which form new sets of variables or axes that are uncorrelated with one another (Helsel and Hirsch, 2002). Results of 

principal component analysis of all data and data subsets for 

total-recoverable metals and for SVOCs from the principal 

highways indicate that 80 to 95 percent of the variance is 

explained by a single variable. This likely stems from the high 

degree of correlation between most of the constituents. For 

example, the average Pearson correlation coefficient for totalrecoverable metals and SVOCs in samples of runoff collected 

from the principal highway, Interstate 95, was about 0.83 

(table 33). The Pearson product moment correlation coefficient 

measures the degree of linear relation between two variables. 

The correlation coefficient ranges from -1 to +1. A negative 

coefficient indicates that one variable tends to increase as the 

other decreases, and a positive coefficient indicates that the 

two variables tend to increase together. Unfortunately, the high 

degree of correlation between most of the constituents makes 

it difficult to identify individual source patterns.

Further research indicates that the use of ratios between 

certain PAH compounds, and ratios of the dominant particulate-associated PAHs to P and to selected metals, may provide 
86 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 33. Pearson correlation coefficients for total nutrients, total-recoverable metals, and polyaromatic hydrocarbons in samples of highway runoff collected from Interstate 95 in Lexington and Waltham, Massachusetts, 2005–07. [<, less than value shown; mm, millimeters] Constituent

Nitrogen

Phosphorus

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Anthracene

]anthracene a Benzo[

]pyrene a Benzo[

]fluoranthene b Benzo[

]perylene ghi Benzo[

]fluoranthene k Benzo[

Chrysene

Fluoranthene

]pyrene cd Indeno[1,2,3-

Phenanthrene

Pyrene

Perylene

Phosphorus 0.762Cadmium 0.742 0.726Chromium 0.676 0.751 0.738Copper 0.776 0.804 0.866 0.925Iron 0.645 0.854 0.872 0.904 0.925Lead 0.646 0.760 0.827 0.870 0.924 0.929Manganese 0.754 0.777 0.925 0.895 0.949 0.938 0.909Nickel 0.673 0.825 0.877 0.886 0.916 0.955 0.851 0.930Zinc 0.749 0.799 0.870 0.951 0.960 0.960 0.925 0.958 0.943Anthracene 0.428 0.743 0.742 0.561 0.658 0.799 0.642 0.649 0.786 0.696Benzo[a]anthracene 0.565 0.809 0.822 0.707 0.799 0.898 0.814 0.771 0.826 0.825 0.928Benzo[a]pyrene 0.647 0.828 0.848 0.751 0.864 0.912 0.873 0.833 0.842 0.850 0.807 0.941Benzo[b]fluoranthene 0.603 0.803 0.827 0.743 0.861 0.910 0.871 0.825 0.840 0.848 0.821 0.948 0.993Benzo[ghi]perylene 0.718 0.765 0.886 0.684 0.846 0.846 0.831 0.819 0.782 0.803 0.696 0.859 0.960 0.932Benzo[k]fluoranthene 0.543 0.808 0.740 0.743 0.819 0.895 0.839 0.788 0.835 0.835 0.840 0.936 0.939 0.963 0.813Chrysene 0.611 0.827 0.879 0.761 0.849 0.934 0.841 0.833 0.881 0.869 0.914 0.988 0.943 0.942 0.884 0.915Fluoranthene 0.540 0.777 0.838 0.662 0.758 0.869 0.754 0.742 0.819 0.789 0.949 0.983 0.898 0.897 0.834 0.873 0.984Indeno[1,2,3-cd] pyrene 0.698 0.801 0.895 0.718 0.874 0.889 0.857 0.841 0.830 0.836 0.766 0.910 0.983 0.965 0.991 0.871 0.931 0.885Phenanthrene 0.445 0.738 0.762 0.596 0.656 0.809 0.642 0.655 0.789 0.712 0.973 0.927 0.791 0.792 0.703 0.793 0.929 0.970 0.767Pyrene 0.613 0.816 0.887 0.721 0.820 0.911 0.814 0.807 0.857 0.838 0.912 0.978 0.941 0.930 0.905 0.879 0.992 0.987 0.942 0.935Perylene 0.702 0.871 0.827 0.697 0.832 0.886 0.790 0.800 0.857 0.815 0.853 0.935 0.970 0.972 0.886 0.962 0.928 0.889 0.929 0.806 0.917Suspended sediment 0.318 0.552 0.497 0.599 0.643 0.702 0.731 0.610 0.606 0.678 0.626 0.761 0.745 0.802 0.573 0.887 0.698 0.648 0.636 0.547 0.632 0.728Suspended sediment 

<0.063 mm in diameter 0.661 0.862 0.882 0.903 0.925 0.994 0.907 0.937 0.963 0.952 0.798 0.893 0.905 0.899 0.845 0.880 0.937 0.875 0.888 0.821 0.916 0.880
Sources of Highway-Runoff Constituents 87

qualitative estimates of the proportion of most highway-runoff 

constituents attributable to likely sources. Comparisons of 

ratios of PAH compounds in environmental samples to PAH 

ratios from known sources are commonly used to determine 

potential sources (Breault and other, 2005; Lima and others, 

2005; Yunker and others, 2002; Dickhut and others, 2000). 

Ratios are derived for PAH compounds of the same molecular 

mass to avoid differences in volatility, water solubility, and 

absorption (Yunker and others, 2002).

For this study, ratios for anthracene to anthracene 

plus phenanthrene (An/(An+Phe)), fluoranthene to fluoranthene plus pyrene (Fl/(Fl+Py)), benzo[a]anthracene to 

benzo[a]anthracene plus chrysene (Ba/(Ba+Chr)), and 

indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus 

benzo[ghi]perylene (Ip/(Ip+Bghi)) were computed from 

sample pairs for each highway. The median ratios for these 

PAH compounds in composite samples of highway runoff 

for each highway in this study are listed with ratios related to 

potential sources of highway PAHs reported in the literature 

in table 34. Ratios for An/(An+Phe) greater than 0.1 generally 

indicate combustion sources, and ratios less than 0.1 indicate 

petroleum sources (Yunker and others 2002). The median 

ratios for An/(An+Phe) in this study ranged from about 0.13 

to 0.24, and most of these ratios are within the range of ratios 

for gasoline-engine exhaust emissions (table 34). The median 

ratios for An/(An+Phe) in composite samples of highway 

runoff during, or shortly after, winter plowing operations 

(runoff events in January, February, March, and April 2006, 

and March and April 2007) on the principal highways were 

closer to 0.08. This lower ratio indicates that the dominant 

source of individual PAHs could shift from gasoline-engine 

exhaust emissions to asphalt wear during the winter, possibly 

as the result of contact wear of the asphalt surface during snow 

plowing. Transition breaks between sources of combustion and 

petroleum are less certain for ratios for Fl/(Fl+Py) (Yunker and 

others, 2002). The median ratios for Fl/(Fl+Py) in this study 

ranged from about 0.53 to 0.57 (table 34), which were slightly 

higher than ratios for Fl/(Fl+Py) in automobile exhaust generated from gasoline engines (Cadle and others, 2001) but within 

the rather large range of ratios for diesel-exhaust emissions 

(Westerholm and Egebäck, 1994; Strandell and others, 1994; 

Rogge and others, 1993). However, it is unlikely that these 

ratios result from diesel-exhaust emissions because of the low 

inter-highway variability and the dissimilar heavy truck traffic 

on the different highways. Furthermore, the range of ratios 

for Fl/(Fl+Py) calculated by Miguel and others (1998) is more 

precise for diesel-exhaust emissions than for gasoline-exhaust 

emissions, and the ratios are lower than those calculated for 

exhaust from gasoline engines. The median environmental 

PAH ratios for the highways in this study also might be higher 

than those in the literature as a result of further improvements 

in engine technology and fuel formulations since the test 

data were reported. Differences in the age of engines, emission controls, vehicle speed, fuel formulations, and engine 

operational procedures affect the assemblage of PAHs, thus, 

potentially affecting the final ratios (Lima and others, 2005). 

For example, ratios for Fl/(Fl+Py) derived from emission 

samples from older catalyst-equipped automobiles (Rogge and 

others, 1993) are lower than ratios from tests conducted with 

newer model vehicles (Cadle and others, 2001), and although 

the research by Marr and others (1999) indicated that fuel was 

not the only source of the PAHs in exhaust, they reported that 

particle-phase emission factors correlated well for most PAH 

compounds in gasoline. The median ratios for Ba/(Ba+Chr) in 

composites of highway runoff in this study ranged from about 

0.30 to 0.46 (table 34), which are within the range of ratios 

for automobile exhaust generated by gasoline engines (Cadle 

and others, 2001). The higher ratios for Ba/(Ba+Chr) for some 

of the highways may have been affected by larger amounts 

of diesel-exhaust emissions from heavy trucks. The presence 

of benzo[a]athracene and the absence of chrysene in diesel 

exhaust results in an increased Ba/(Ba+Chr) ratio. The median 

ratios for Ip/(Ip+Bghi) in composite samples of highway 

runoff in this study ranged from about 0.44 to 0.48 (table 34); 

this range is greater than the range of ratios for gasoline 

and diesel exhaust emissions. These ratios likely reflect a 

blend of different potential sources that include gasoline and 

diesel exhaust emissions, and asphalt and tire wear. Ratios 

for Fl/(Fl+Py), Ba/(Ba+Chr), and (Ip/(Ip+Bghi), calculated 

on the basis of available concentration data for samples of 

suspended sediment (table 21 in the back of the report), are 

similar to the median ratios calculated from the concentration 

data for the composite samples of highway runoff. Ratios for 

An/(An+Phe), Fl/(Fl+Py), and (Ip/(Ip+Bghi) also are similar 

to ratios for precipitation calculated on the basis of the mean 

concentration of the above PAHs reported for precipitation in 

Narragansett Bay, Rhode Island (Latimer, 1997). However, 

these similarities more likely indicate that automobile emissions are the source of the PAHs in the atmosphere rather than 

wet deposition is the source of PAHs in highway runoff.

In this study, the median concentrations of total P and 

most metals measured in samples of highway runoff from 

each principal highway were compared to the concentrations 

expected from automobile emissions. Average emission rates 

for Cr, Cu, Ni, and Pb in oxygenated fuel, using different standardized-test procedures and different automobiles, are similar 

to the emission rates for major particulate-associated PAHs 

(chrysene and indeno[1,2,3-cd]pyrene), but the emission rates 

for P, Fe, and Zn are reported to be about 6 to 38 times greater 

than the emission rates for the respective PAHs (Cadle and 

others, 2001). Concentrations of each element in automobile 

exhaust were estimated on the basis of the average ratio for the 

emission rate of the individual element to the emission rates 

for chrysene and indeno[1,2,3-cd]pyrene in exhaust, which 

were obtained from the literature (Cadle and others, 2001). 

Assuming the dispersion for both metals and PAHs associated 

with exhaust particles is similar, exhaust emissions account 

for only a small fraction of metals measured in samples of 

highway runoff. For example, ratios for median concentrations 

of total P and total-recoverable Cu and Fe to the concentration 

of the respective elements estimated from the median concentrations of chrysene and indeno[1,2,3-cd]pyrene in samples of 
88 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 34. Median ratios between selected polyaromatic hydrocarbons in composites of highway runoff for eight highways in Massachusetts, 2005–07, and ratios for common sources of polyaromatic hydrocarbons found in highway runoff. [PAHs, polyaromatic hydrocarbons; An, anthracene; Phe, phenanthrene; Fl, fluoranthene; Py, pyrene; Ba, benz[a]anthracene; Chr, chrysene; Ip, indeno[1,2,3-cd]pyrene; Bghi, benzo[ghi]perylene; *, median value based on three samples or less; --, insufficient data to compute ratio; PAH ratios estimated from the average of the range values] Highway-runoff monitoring station or potential source of PAHs Median ratio for selected PAHs in composite samples of highway runoff or range of ratios for selected PAHs as sources reported in literature An/(An+Phe) Fl/(Fl+Py) Ba/(Ba+Chr) Ip/(Ip+Bghi) Highway-runoff monitoring station Route 119 0.14 0.56 0.34 0.47 Route 8 0.24 0.53* 0.46* 0.47* Interstate 195 0.23* 0.55 0.39 0.45 Route 2 0.13 0.57 0.35 0.44 Interstate 190 0.23 0.54 0.33 0.47 Interstate 495 0.17 0.54 0.39 0.45 Interstate 95 0.15 0.55 0.30 0.48 Interstate 93 0.16 0.56 0.32 0.47 Potential sources of PAHs Asphalt 0.081,2 0.331 and 0.442 0.161 and 0.503 0.52 to 0.543 Brake dust -- 0.304 0.474 -- Gasoline exhaust emissions 0.13 to 0.175 0.47 to 0.525 0.29 to 0.485 -- Diesel exhaust emissions 0.124, 0.106, and 0.087 0.374, 0.616, and 0.557 0.357 -- Highway tunnel, diesel exhaust emissions -- 0.41 to 0.438 0.56 to 0.688 -- Highway tunnel, gasoline exhaust emissions -- 0.43 to 0.478 0.41 to 0.518 0.27 to 0.338

Precipitation 0.149 0.499 0.189 0.439Road dust 0.183 .423 0.133 0.513Road-side vegetation -- 0.56 0.54 to 0.61 --

Tire particles 0.041 0.111, 0.174, 0.17-.2910, and 0.2011 -- 0.911

Used oil (gasoline engine) 0.223 0.511, 0.303,11 0.503 0.331 and 0.183

1Breault and others, 2005; 2Brandt and De Groot (2001); 3Mean values from Yunker and others (2002); 4Rogge and others (1993); 5Cadle and others (2001); 6Westerholm and Egebäck (1994); 7Strandell 

(1994); 8Miguel and others (1998); 9Latimer (1997); 10Gadd and Kennedy (2003); 11King County and SPU (2004).
Sources of Highway-Runoff Constituents 89

highway runoff collected at the principal highways indicate 

that less than 3 percent of the constituents are accounted for 

by exhaust emissions from gasoline engines, whereas ratios 

for median concentrations for total-recoverable Cr, Mn, Ni, 

Pb, and Zn to the concentration of the respective elements 

estimated from the median concentrations of chrysene and 

indeno[1,2,3-cd]pyrene indicate that from about 4 to 13 

percent of the of the constituents are accounted for by exhaust 

emissions from gasoline engines.

Atmospheric deposition also can affect the quality of 

highway runoff. Atmospheric deposition of constituents 

measured in samples of highway runoff occurs in the form 

of dry and wet deposition. Dry deposition includes settleable particulates, aerosols, gases, and vapors. The deposition 

of these particles is dependent on the size, surface area, and 

mass of the particle (Legge, 1990). Larger airborne particles, 

greater than a few micrometers in diameter, result from natural 

sources of mechanical abrasion and wind erosion, and are 

subject to gravitational settling, whereas smaller particles are 

removed from the atmosphere by precipitation scavenging 

(Colman and others, 2001). Available data for dry deposition 

rates are sparse, and particle chemistry and deposition rates 

are subject to local conditions. However, concentration data 

on ammonia, nitrate, and most major ions, which are available 

from the National Atmospheric Deposition Program/National 

Trends Network (NADP/NTN), are more common. Concentrations of total P were unavailable; however, concentrations 

of P in precipitation generally are too low to be measured 

accurately (Colman and others, 2001). Concentrations of 

major ions in precipitation do not constitute a large fraction of 

the major ions in samples of highway runoff, except for Mg 

and SO4

. Comparisons of annual precipitation weighted-mean 

concentrations (concentration for each storm is weighted by 

the respective volume) of major ions other than Mg and SO4 

in 2005 and 2006 for NADP/NTN site MA13 in Lexington, 

Massachusetts (NADP/NTN, 2008), to mean concentrations 

for the same constituents in composite samples of highway 

runoff from non-winter storms (where the effect of addition of 

deicing compounds is eliminated) for the principal highway 

Interstate 95 in parts of Lexington and Waltham, Massachusetts, indicate that less than about 4 percent of the concentrations of the respective major ions is explained by atmospheric 

deposition in the non-winter months. In contrast, weightedmean concentrations of Mg and SO4

 in precipitation may 

account for about 10 and 21 percent, respectively, of the mean 

concentrations in non-winter highway runoff. Weighted-mean 

concentrations of NH4

 and NO3 in precipitation may account 

for about 55 percent of the mean concentrations of total N in 

all samples (winter and non-winter) collected at Interstate 95 

in this study. Concentrations of total N in precipitation likely 

constitute a greater percentage of total N in highway runoff 

at the other principal highways because the concentrations 

of total N in samples of highway runoff at those sites were 

significantly different (table 22). Data on concentrations of 

metals in precipitation in the Massachusetts area could not be 

located; however, concentrations of metals measured in wet 

precipitation in Michigan, Illinois, and Indiana (Coleman and 

others, 2001) are low and likely represent only a small fraction 

of the metal content measured in samples of highway runoff in 

Massachusetts.

Local soils and highway-berm soil can represent much of 

the suspended sediment entrained in highway runoff (Gupta 

and others, 1981). As a result, background soil adjacent to 

each highway can affect the composition and concentrations of 

many constituents in highway runoff. Soils often are washed 

onto the roadway surface during stormflows or are directly 

deposited on the road by automobiles (for example, vehicles 

that have come into contact with adjacent unpaved shoulders).

Soil is natural material occupying the portion of the 

earth mainly composed of mineral and organic materials and 

develops from surficial material that unless otherwise specified can include any unconsolidated deposits down to bedrock. 

Geologic processes, such as weathering and erosion, break 

bedrock down into small particles of sediment. Sediments 

such as clay, silt, sand, gravel, and other loose deposits that lie 

on top of bedrock are grouped together in the general category 

of surficial materials. These materials are not soils, but are 

the deeper earth materials that lie between the soil zone and 

the underlying bedrock. Soils commonly develop by weathering of the uppermost part of these materials. Differences 

in weathering as a function of climate, presence of salt, and 

topography also can affect the development of soils (Ritter and 

others, 1995). This may explain in part the difference between 

the composition of soil in samples collected in southeastern 

Massachusetts, USEPA level III ecoregion 84 on and near 

Cape Cod, and samples collected elsewhere in Massachusetts 

in areas with similar surficial materials (table 19 in the back of 

the report).

The extent to which background soils contribute to 

the concentrations of P, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in 

highway runoff was estimated on the basis of the median 

concentrations of suspended sediment in composite samples 

of highway runoff (table 16 in the back of the report) and the 

median concentrations of each of these constituents in background samples of soils from each of the principal highways 

(table 19 in the back of the report). The median concentrations 

for P, Cr, Fe, Mn, Ni, and Zn in soil were adjusted on the basis 

of quality-control data to account for differences between 

the digestion techniques used in the analytical methods for 

the soil and whole-water samples. These initial estimates 

indicate that background soils account for on average about 

37 percent of the median P concentration, 100 percent of the 

median Cr concentration, 4 percent of the median Cu concentration, 53 percent of the median Fe concentration, 54 percent 

of the median Mn concentration, 15 percent of the median 

Ni concentration, 44 percent of the median Pb concentration, 

and 2 percent of the median Zn concentration in samples of 

highway runoff from the principal highways. Except for Cr, 

these values are likely conservative because the values were 

estimated without regard to the distribution of the particle 

sizes for the two media—soil and sediment. The distribution 

of particle sizes in samples of soil or sediment can have great 
90 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

effects on the concentrations of many constituents. The disproportionate differences in concentrations of inorganic constituents relative to grain size are well documented (table 18 in the 

back of the report; fig. 24; Breault and others, 2005; Smith, 

2002, 2005; Horowitz, 1991; Horowitz and Elrick, 1987; 

Forstner and Wittmann, 1981; Salomons and Forstner, 1984). 

In general, surface area and trace-element concentrations tend 

to increase with a decrease in particle-grain size. Furthermore, 

the silt- and clay-sized particle group contains more clay 

minerals, which typically have higher sorptive capacities, than 

other groups. In contrast, concentrations of Cr typically are 

greater in the coarse fractions of sediment (table 18 in the back 

of the report; fig. 24; Breault and others, 2005; Smith, 2002, 

2005); therefore, the contribution of Cr from local soils, which 

contain a higher proportion of coarse particles than highway 

sediments, results in an overestimation of Cr in highway 

sediments.

 Highway-berm soils often are composed of soil excavated from nearby locations during highway construction. The 

concentrations of many metals in berm soils become enriched 

over time through the deposition of small particulates emitted 

from automobiles and pavement wear. Winter sanding of pavement surfaces also contributes to the buildup of berm soils 

near the highway shoulder. As a result, the median concentrations and upper ranges of concentrations of most constituents, 

except P, in samples of highway-berm soils increase with 

the AADT volume of the highways (fig. 25). Moreover, the 

chemical composition of these berm soils often is comparable 

to the chemical composition of samples of suspended sediment 

in highway runoff. This is further illustrated by normalizing 

data collected in this study on the basis of the particle-size 

distribution to reduce the disproportionate differences between 

concentrations of constituents that are affiliated with sediment relative to grain size. Specifically, concentrations of Cu, 

Cr, Fe, Mn, Ni, P, Pb, and Zn in suspended sediment for each 

principal highway (fig. 25) were estimated on the basis of the 

concentrations of the respective constituents affiliated with the 

three particle-size fractions in sieved samples of suspended 

sediment to reflect the particle-size distribution of the five 

respective berm samples (table 20 in the back of the report) for 

each principal highway. The distributions of concentrations of 

the selected elements in highway berm and the distributions 

of normalized concentrations measured in suspended sediment were most similar for P and Zn, with few exceptions. In 

several cases, the ranges of concentrations of Cu, Fe, Pb, Mn, 

and Ni in samples of highway berm soil overlapped the ranges 

of the estimated concentrations in suspended sediment. These 

data indicate that erosion or mechanical transport of highwayberm soils onto the paved surface is potentially a large source 

for P and other metals. Furthermore, although the concentrations of most constituents (except for Cr and P) in wintermaintenance sand were relatively low compared to concentrations measured in samples of highway berm (fig. 25), high 

concentrations of maintenance sand, which contain Cu, Cr, Fe, 

Pb, Mn, and Ni, and Zn in samples of winter runoff can cause 

large increases in concentrations of these constituents and, as 

discussed earlier, may account for most of the P concentration.

Thus far, much of the concentrations of PAHs, major 

ions, and metals can be accounted for by exhaust emissions, 

road wear, atmospheric deposition, local and berm soils, and 

highway maintenance materials. However, these potential 

sources do not fully account for concentrations of Cu, Zn, and 

phthalates measured in samples of highway runoff. Sources 

reported to contribute substantial amounts of Cu and Zn in 

highway and urban runoff are brake and tire wear (Hjortenkrans and others, 2007; Hulskotte and others, 2006; Councell 

and others, 2004; Gadd and Kennedy, 2000). The composition 

of individual brake pads can vary widely from manufacturer 

to manufacturer, and the composition also can vary between 

front and rear brakes (Hjortenkrans and others, 2007). Garg 

and others (2000) report that 19 different elements were found 

in the analysis of 7 different brake pads, and the analysis of 

most brakes indicated that Fe, Cu, Ba, and S were the major 

elements associated with particle matter emitted during brake 

wear. As discussed earlier, the size of the emission particle 

can have a large effect on where the particles are deposited. 

Laboratory brake-wear tests indicated that 3 to 30 percent of 

the break debris falls on the road surface, 16 to 22 percent is 

retained on the wheel, and 8 to 25 percent is retained on the 

vehicle steering and suspension equipment (Sanders and others, 2003). The latter two depositional areas are likely subject 

to wash-off during rainstorms. Emission rates for break wear 

depend strongly on traffic conditions and brake temperature, 

but Garg and others (2000) report that emission rates for Fe 

and Cu in brake wear are 2.21 and 0.70 mg/mi, respectively, 

which are more than an order of magnitude greater than 

emission rates reported for exhaust emissions from gasoline 

engines. Given these emission rates, brake wear as a source of 

Cu can easily account for the mass closure in concentrations 

measured in samples of highway runoff. Similarly, phthalate esters, including bis(2-ethylhexyl) phthalate, di-n-butyl 

phthalate, di-n-octyl phthalate, and diethyl phthalate, are 

reported to be used in brake-pad construction (King County 

and SPU, 2004); this may explain much of the observed concentrations in composite samples of highway runoff.

In contrast, anthropogenic sources of Zn have largely 

been linked to tire emissions. Zn is used to facilitate vulcanization of the rubber in the manufacturing process for tires 

(Councell and others, 2004), and as a result, Zn can account 

for about 1 percent of the mass of the tread particles (Hjortenkrans and others, 2007; Breault and others, 2005; Councell 

and others, 2004). To determine the relative magnitude of 

Zn loading to the highway surface as a function of tire wear, 

the load of Zn for a single day was estimated for each of the 

principal highways on the basis of an average tire-tread wear 

rate of about 0.08 g/mi/tire (Councell and others, 2004), a 

tread-wear composition consisting of 1-percent Zn, the AADT 

volumes (assuming four wheels per vehicle) for each principal highway (table 1), and an average linear distance of about 

300 ft for the sites on the principal highways. These simple 

estimates indicate that for a 0.5-in. rainstorm, the estimated 
Sources of Highway-Runoff Constituents 91 Figure 24. Concentrations of total-recoverable metals in three particle-size ranges of suspended sediment in samples of highway runoff collected by automatic samplers at the principal highways in Massachusetts, 2005–07.

0.005

0.05

0.5

5 Total-recoverable phosphorus

CONCENTRATION, IN PARTS PER HUNDRED

INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119 INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119 INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119

Total-recoverable iron

40

400

4,000 Total-recoverable manganese

CONCENTRATION, IN PARTS PER MILLION

Total-recoverable zinc Total-recoverable chromium

4

40

400

Total-recoverable nickel

CONCENTRATION, IN PARTS PER MILLION

Total-recoverable lead Total-recoverable copper

EXPLANATION

 Particles of 0.250 to 2.0 millimeters

 Particles of 0.063 to less than 0.250 millimeter 

 Particles less than 0.063 millimeter
92 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 25. Distribution of concentrations of selected constituents measured in samples of berm material 

from four principal highways and in samples of highway-maintenance sand, and estimated concentrations 

of berm material derived from samples of suspended-sediment quality and particle size in Massachusetts, 

2005–07. Five samples of highway-berm material were collected within 1 foot of the edge of the pavement in 

the vicinity of each of eight highway-monitoring stations. Eight samples of highway-maintenance sand were 

collected.

0

5

10

15

20

25

30

35

40

45

50

55

60

LEAD

CONCENTRATION, IN PARTS PER MILLION

0

1

2

3

4

IRON

CONCENTRATION, IN PARTS PER HUNDRED

 ROUTE 119 INTERSTATE 495

 HIGHWAY 

 SAND

 ROUTE 2 INTERSTATE 95

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION

 Measured in berm

 material

Estimated in berm

material

Measured in 

highway sand
Sources of Highway-Runoff Constituents 93

0

20

40

60

80

100

120

140

160

180

200

 COPPER

CONCENTRATION, IN PARTS PER MILLION

0

200

400

600

800

1,000

1,200

1,400

2,000

2,200

2,400

2,600

2,800

CHROMIUM

CONCENTRATION, IN PARTS PER MILLION

 ROUTE 119 INTERSTATE 495

 HIGHWAY 

 SAND

 ROUTE 2 INTERSTATE 95

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION

 Measured in berm

 material

Estimated in berm

material

Measured in 

highway sand

Figure 25. Distribution of concentrations of selected constituents measured in samples of berm material 

from four principal highways and in samples of highway-maintenance sand, and estimated concentrations 

of berm material derived from samples of suspended-sediment quality and particle size in Massachusetts, 

2005–07. Five samples of highway-berm material were collected within 1 foot of the edge of the pavement in 

the vicinity of each of eight highway-monitoring stations. Eight samples of highway-maintenance sand were 

collected.—Continued
94 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 25. Distribution of concentrations of selected constituents measured in samples of berm material 

from four principal highways and in samples of highway-maintenance sand, and estimated concentrations 

of berm material derived from samples of suspended-sediment quality and particle size in Massachusetts, 

2005–07. Five samples of highway-berm material were collected within 1 foot of the edge of the pavement in 

the vicinity of each of eight highway-monitoring stations. Eight samples of highway-maintenance sand were 

collected.—Continued

0

100

200

300

400

500

600

MANGANESE

CONCENTRATION, IN PARTS PER MILLION

0

20

40

60

 NICKEL

CONCENTRATION, IN PARTS PER MILLION

 ROUTE 119 INTERSTATE 495

 HIGHWAY 

 SAND

 ROUTE 2 INTERSTATE 95

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION

 Measured in berm

 material

Estimated in berm

material

Measured in 

highway sand
Sources of Highway-Runoff Constituents 95

Figure 25. Distribution of concentrations of selected constituents measured in samples of berm material 

from four principal highways and in samples of highway-maintenance sand, and estimated concentrations 

of berm material derived from samples of suspended-sediment quality and particle size in Massachusetts, 

2005–07. Five samples of highway-berm material were collected within 1 foot of the edge of the pavement in 

the vicinity of each of eight highway-monitoring stations. Eight samples of highway-maintenance sand were 

collected.—Continued

0

0.01

0.02

0.03

0.04

0.05

0.06

PHOSPHORUS

CONCENTRATION, IN PARTS PER HUNDRED

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

ZINC

CONCENTRATION, IN PARTS PER MILLION

 ROUTE 119 HIGHWAY 

SAND

 ROUTE 2 INTERSTATE 95

INTERSTATE 495

25th percentile

75th percentile

Median

 Maximum

 Minimum

EXPLANATION

 Measured in berm

 material

Estimated in berm

material

Measured in 

highway sand
96 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

concentration of Zn emitted from tire wear was about 1.5 to 6 

times greater than the median non-winter concentrations of Zn 

for the principal highways. For the estimates, it was assumed 

that all of the tire particles are retained on the highway, which 

is highly unlikely given the small diameter of the tire particles. 

In one study (Rogge and others, 1993), 30 percent of the mass 

of tire-wear particles measured near the street surface was 

found in air-quality samples at more than 200 ft above the 

street. Accurate load estimates for Zn as a function of tire wear 

are difficult to make because tire-emission rates vary widely 

depending on tire construction, vehicle weight, and pavement and driving conditions. Although Councell and others 

(2004) suggest that about 0.08 g/mi/tire is a reasonable rate 

for average driving conditions, they also report emission rates 

ranging from about 0.002 to about 40 g/mi/tire. Nevertheless, 

the evidence indicates that tire-wear is a substantial source for 

Zn in highway runoff, and other material testing indicates that 

some tires also may be a source of bis(2-ethylhexyl)phthalate 

(King County and SPU, 2004).

Other Anthropogenic and Natural Organic 

Compounds

The vast majority of highway-runoff data documents the 

concentrations of major ions, nutrients, metals, PAHs, and suspended sediments; however, few data sets document the concentration or detection for some of the lesser-known anthropogenic and natural organic compounds that have recently been 

detected in surface water and groundwater throughout the 

Nation (Zaugg, and others, 2006a). In this study, a subset of 

samples of highway runoff were collected at the primary sites 

on the principal highways and on Interstate 93 and analyzed 

for an additional 62 organic compounds (table 17 in the back 

of the report). These analyses include many compounds that 

typically are associated with industrial and household wastewater (Paxéus and others, 1992), such as nonionic surfactants, 

caffeine, indicators of plant sterols, indicators of fecal bacteria, flame retardants, wood preservatives, gasoline and diesel 

compounds, antioxidants, and personal care products.

In 15 samples of highway runoff, 45 of the 62 compounds were detected at least once, and 23 compounds were 

detected at concentrations greater than the LTMDL (table 35). 

Anthraquinone, bisphenol A, camphor, and cholesterol were 

the most frequently detected compounds. Although some compounds were detected less frequently in samples of highway 

runoff collected on Route 119, the frequency of detection for 

most compounds generally was similar among the other highways. About one-third of the compounds that were detected 

are likely attributable to vehicle fuels, lubricants, antifreeze, 

windshield fluids, chemical treatments of the engine compartments, finish-paint coats, automotive panels, and other vehicle 

components. Beta-sitosterol and cholesterol can originate 

from plant sources; 3beta-coprostanol and beta-stimastanol 

are indicators of fecal bacteria (Zaugg, and others, 2006a). 

The sources for many of the remaining compounds may be 

leachates from highway litter. These compounds consist of 

caffeine, cotinine, and various flavor enhancers used in beverages, cigarettes, and ointments commonly found in food wrappers, containers, and other litter along the edge of the highway.

Relations of Concentrations of 

Selected Elements and Organic 

Compounds to Suspended Sediment

Suspended sediment in runoff often can cause degradation in the receiving waters by affecting the clarity of the 

water and through large-scale depositions. Many trace elements and hydrophobic-organic compounds are associated 

with sediments (Breault and others, 2005; Smith, 2002, 2005; 

Lopes and Dionne, 1998; Horowitz, 1991; Gupta and others, 

1981). Suspended sediment can represent a major transport 

mechanism for many constituents in highway runoff. Results 

of laboratory analysis for sieved samples of suspended sediment collected in highway runoff for this study indicate that 

highway suspended sediment contains high concentrations of 

P, trace elements, PAHs, and phthalates (tables 18 and 21). 

Results also indicate that in many cases, the fine fraction of 

sediment less than 0.063 mm in diameter was more enriched 

compared to the coarser sediment fractions (figs. 24 and 26).

Concentrations of suspended sediment measured in samples of highway runoff were examined as a potential surrogate 

for concentrations of sediment-affiliated constituents. Results 

of statistical tests between concentrations of suspended sediment and concentrations of total P, total-recoverable metals, 

and PAH compounds in samples collected at Interstate 95 

indicate a positive relation between the test pairs (table 33). 

Furthermore, correlations are stronger between concentrations of suspended sediment less than 0.063 mm in diameter 

and concentrations of total P, total-recoverable metals, and 

PAH compounds (table 33) than for concentrations of total 

suspended sediment. Pearson correlation coefficients for total 

P, total-recoverable metals, and PAH compounds are 0.86, 

0.88 to 0.99, and 0.80 to 0.94, respectively (calculated from 

data presented in table 33). These data further demonstrate 

that the distribution of grain size in suspended sediment may 

have an effect on the concentration of the various constituents 

in samples of highway runoff. Regression techniques may 

provide reasonable estimates for many of these constituents 

on the basis of concentrations of suspended sediment; however, such methods may not be transferable to other locations 

without additional measurements of highway runoff, which 

often require substantial capital and time. Instead, planninglevel estimates of concentrations of many total-recoverable 

elements can be made directly from the respective constituent concentrations in samples of sieved suspended sediment 

and from the concentrations of specific particle classes of 

suspended sediment in samples of highway runoff. To demonstrate the applicability of this method, EMCs of Cu were 
Relations of Concentrations of Selected Elements and Organic Compounds to Suspended Sediment 97 Figure 26. Distribution of concentrations for selected polyaromatic hydrocarbons in two particle-size ranges for suspended sediment in samples of highway runoff collected by automatic samplers at the principal highways in Massachusetts, 2005–07.

0

8,0006,0004,0002,000

10,000

 9,10-Anthraquinone

CONCENTRATION, IN MICROGRAMS PER KILOGRAM

INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119 INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119 INTERSTATE

95

INTERSTATE

495

ROUTE 2 ROUTE 119

Benzo[a]pyrene Perylene

0

5,000

25,00020,00015,00010,000

Benzo[e]pyrene

CONCENTRATION, IN MICROGRAMS PER KILOGRAM

Phenanthrene Benzo[b]fluoranthene

0

80,00060,00040,00020,000

120,000100,000

Pyrene

CONCENTRATION, IN MICROGRAMS PER KILOGRAM

Fluoranthene Bis (2-ethylhexyl) phthalate

EXPLANATION

 Particles greater than or  equal to 0.063 millimeter in  diameter

 Particles less than 0.063  millimeter in diameter
98 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 35. Frequency of detection, frequency of detection greater than or equal to the long-term method detection level, and possible sources of selected anthropogenic and natural organic compounds in 15 composite samples of highway runoff collected at 5 sites in Massachusetts, 2006–07.—Continued [LTMDL, long-term method detection level; %, percent; possible compound sources from Zaugg and others, 2006a; U.S. Environmental Protection Agency, 2002; Agency for Toxic Substances and Disease Registry, 2005] Compound name Frequency of detection Frequency of detection above LTMDL Concentration at LTMDL Possible compound uses or sources 1-Methylnaphthalene 60 20 0.03 2–5% of gasoline, diesel fuel, or crude oil 2,6-Dimethylnaphthalene 27 7 0.05 Diesel/kerosene (trace in gasoline) 2-Methylnaphthalene 73 33 0.03 2–5% of gasoline, diesel fuel, or crude oil 3,4-Dichlorophenyl isocyanate 14 0 0.06 Degradate of diuron, a noncrop herbicide

3beta-Coprostanol 33 33 0.38 Carnivore fecal indicator

3-Methyl-1H-indole (skatol) 7 0 0.07 Fragrance, stench in feces, indicator of decaying animal 

tissue, and coal tar

4-Cumylphenol 7 0 0.13 Nonionic detergent or metabolite

4-Nonylphenol (total, NP) 40 13 1.2 Nonionic detergent or metabolite

4-tert-Octylphenol 60 53 0.11 Nonionic detergent or metabolite

5-Methyl-1H-benzotriazole 40 40 0.35 Antioxidant in antifreeze and deicers

Acetophenone 60 60 0.07 Fragrance in detergent and tobacco, flavor in beverages

Anthraquinone 93 86 0.08 Manufacture dye/textiles, seed treatment, bird repellent

Benzophenone 13 13 0.1 Fixative for perfumes and soaps

beta-Sitosterol 87 87 0.11 Plant sterol

beta-Stigmastanol 7 7 0.22 Herbivore fecal indicator (digestion of sitosterol)

Bisphenol A 93 73 0.22 Manufacture polycarbonate resins, antioxidant

Caffeine 80 80 0.06 Beverages

Camphor 93 53 0.09 Flavor, odorant, ointments

Carbazole 80 30 0.12 Manufacture dyes, explosives, and lubricants

Cholesterol 93 93 0.3 Often a fecal indicator, also a plant sterol

Cotinine 20 13 0.29 Primary nicotine metabolite

N,N-diethyl-meta-toluamide (DEET) 53 27 0.12 Urban uses, mosquito repellent

Dichlorvos 7 0 0.11 Insecticide in pet collars; naled or trichlofon degradate

Diethoxynonylphenol (4-Nonylphenol diethoxylate; NP2EO) 33 20 1.2 Nonionic detergent

Diethoxyoctylphenol (4-tert-Octylphenol diethoxylate; OP2EO) 20 20 0.05 Nonionic detergent
Relations of Concentrations of Selected Elements and Organic Compounds to Suspended Sediment 99

Table 35. Frequency of detection, frequency of detection greater than or equal to the long-term method detection level, and possible sources of selected anthropogenic and natural organic compounds in 15 composite samples of highway runoff collected at 5 sites in Massachusetts, 2006–07.—Continued[LTMDL, long-term method detection level; %, percent; possible compound sources from Zaugg and others, 2006a; U.S. Environmental Protection Agency, 2002; Agency for Toxic Substances and Disease Registry, 2005]

 Compound name Frequency of detection Frequency of detection above LTMDL Concentration at LTMDL Possible compound uses or sources

d-Limonene 33 33 0.02 Antimicrobial, antiviral, fragrance in aerosols, major 

constituent in several citrus oils

Indole 7 0 0.08 Pesticide inert ingredient, fragrance in coffee

Isophorone 67 13 0.08 Solvent for lacquer, plastic, oil, silicon, resin

Menthol 50 50 0.05 Cigarettes, cough drops, liniment, mouthwash

Methyl salicylate 40 7 0.07 Liniment, food, beverage, wintergreen scent, ultraviolet 

absorbing lotion

Monoethoxynonylphenol (4-Nonylphenol monoethoxylate; 

NP1EO)

27 0 1.35 Nonionic detergent

p-Cresol 73 47 0.08 Wood preservative

Pentachlorophenol 53 20 0.33 Wood preservative, termite control

Phenol 73 73 0.07 Disinfectant, Manufacture several products, leachate

Tributyl phosphate 20 7 0.11 Antifoaming agent, flame retardant

Triphenyl phosphate 60 13 0.1 Plasticizer, resin, wax, finish, roofing paper

Tri(2-butoxyethyl) phosphate 53 53 0.05 Flame retardant

Tri(2-chloroethyl) phosphate 67 27 0.08 Plasticizer, flame retardant

Tri(dichloroisopropyl) phosphate 73 73 0.05 Flame retardant

1,4-Dichlorobenzene 7 0 0.03 Moth repellent, fumigant, deodorant

Tribromomethane (Bromoform) 13 0 0.03 Previously used in fire-extinguisher fluids, spray can 

propellants, and refrigerator fluid
100 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 27. (A) Concentrations of total-recoverable copper in samples of highway runoff collected from eight stations on 

four highways in Massachusetts in relation to concentrations of total-recoverable copper estimated on the basis of the 

concentration of total-recoverable copper associated with three particle-size ranges in sediment collected from composite 

samples of highway runoff and the concentration and particle-size distribution of suspended sediment in the respective samples 

of highway runoff, and (B) distribution of absolute error between estimated concentrations of total-recoverable copper and 

measured concentrations of total-recoverable copper in samples of highway runoff, Massachusetts, 2005–07.

MEASURED CONCENTRATION OF TOTAL-RECOVERABLE COPPER IN HIGHWAY RUNOFF, 

IN MICROGRAMS PER LITER

ESTIMATED CONCENTRATION OF TOTAL-RECOVERABLE 

COPPER IN HIGHWAY RUNOFF, IN MICROGRAMS PER LITER

1,000

100

10

1

0.1

1 10 100 1,000

25th percentile

75th percentile

Median

 95th percentile

 5th percentile

Mean

1:1 line

EXPLANATION

ABSOLUTE ERROR, IN PERCENT

0

25

50

75

100

ROUTE 2

ROUTE 119

INTERSTATE 95

INTERSTATE 495

A B

ABSOLUTE ERROR
Highway-Runoff Database and Runoff Model Overview 101

estimated for each principal highway (fig. 27) on the basis 

of the EMCs for the three respective particle-size classes of 

suspended sediment in the composite samples (table 16) and 

the concentration of Cu for the respective particle-size classes 

in samples of sieved suspended sediment for each highway 

(table 18 in the back of the report). The absolute difference between measured concentrations of Cu and estimated 

concentrations of Cu for about 95 percent of the samples 

were within 87 percent of the measured total-recoverable Cu 

values (fig. 27). In general, estimated concentrations of Cu 

less than about 90 μg/L tended to be underestimated, particularly for highways other than Route 119. This bias is predictable because the whole-water concentrations of Cu estimated 

from the concentrations of Cu in samples of sieved suspended 

sediment do not account for the dissolved fraction of Cu in the 

whole-water samples. In contrast, the difference between the 

estimated concentration of Cu and the measured concentration 

of Cu in composite samples decreases as the concentration of 

suspended sediment increases. This indicates that most of the 

Cu is partitioned to the solid phase in composite samples with 

high concentrations of suspended sediment. Similar results 

were found for P and most of the total-recoverable metals, 

except for Cr (table 36). These data also indicate that the vast 

majority of sediment-associated concentrations of P and metals are associated with sediment particles less than 0.063 mm 

in diameter. Such information is important for choosing 

appropriate BMPs.

Reasonable planning-level estimates for many constituents can be derived from known concentrations of specific 

constituents affiliated with sediments and from the average 

gradated concentrations of suspended sediment in the composite samples collected in this study. For many applications, the 

average gradated concentrations of suspended sediment measured in composite samples of highway runoff in this study 

can be used in the absence of site-specific concentration data 

for suspended sediment because most results of statistical tests 

between populations of concentrations of suspended sediment 

among the highways and results for median concentrations of 

suspended sediment with AADT volume were not significantly 

different (p value > 0.05). If the concentrations of sedimentaffiliated constituents presented in this study (tables 18 and 

21) are used to estimate planning-level EMCs or loads of 

constituents, the appropriate step is to select data with regard 

to the AADT volume of the principal highways and degree of 

urbanization. Ideally, site-specific samples of suspended sediment would be collected and analyzed for the constituents of 

interest. In theory, gradated samples of road dust, street sweepings, catch-basin-sump sediments, and highway sediments 

from other structural features could be practical substitutes 

for highway suspended sediment, although such testing was 

outside the scope of this study. Use of this method may have 

broad application and provide useful information for stormwater-monitoring applications.

Highway-Runoff Database and Runoff 

Model Overview

The data from this study were entered into the HRBD 

(appendix A) that was developed by the USGS, in cooperation 

with the Federal Highway Administration (FHWA) (Granato 

and Cazenas, 2009). The HRDB was designed to serve as a 

data warehouse for current and future highway-runoff data 

sets. The HRDB application also was developed to serve as a 

data preprocessor for the SELDM (Granato, 2007). SELDM is 

a water-quality model designed to facilitate the estimation of 

runoff flows, and constituent concentrations and loads in highway runoff and in receiving waters at unmonitored sites, using 

site characteristics as a basis for the estimates. Runoff coefficients and EMC statistics are used with SELDM to generate 

random populations of runoff volumes, and constituent concentrations and loads, from regional precipitation statistics and 

site characteristics by use of Monte Carlo simulation methods. 

This information can be used to estimate runoff quantity and 

quality based on site characteristics, and to predict potential 

effects of highway runoff on receiving waters. Proper application of such a model, however, requires technically sound 

statistical estimates of the quality and quantity of runoff and 

receiving waters upstream from the highway outfall. Such 

statistical estimates require technically sound and well-documented data and statistically valid estimation methods appropriate for the data. As SELDM was developed, it was realized 

that use of the model, as well as other analyses and applications of highway-runoff data, would be greatly facilitated by 

a database for complete and comprehensive storage, retrieval, 

and analysis of these data in a consistent format. Thus, the 

HRDB warehouse was created to document data and information from available highway-runoff monitoring studies. The 

HRDB application, which is the graphical user interface and 

associated computer code, can be used to facilitate estimation 

of statistical properties of runoff coefficients, runoff-quality 

statistics, and relations between water-quality variables in 

highway runoff from the available data.

Entering data into version 1.0.0a of the HRDB database 

is an important step in meeting the State and national data 

needs. The need for available, consistent, and technically 

sound runoff-monitoring data was highlighted by the findings 

of the FHWA National Highway Runoff Data and Methodology Synthesis (NDAMS) (Granato and others, 1998; Granato, 

2009). Results of the NDAMS study indicate that knowledge 

of the details of highway-runoff studies is not persistent or 

pervasive and that detailed data and documentation for studies more than 5 years old often are unobtainable because of 

changes in personnel and computer systems (Granato, 2009). 

Similarly, a recent study by the National Cooperative Highway Research Program (NCHRP) concluded that a national 

highway-runoff database, available in the public domain, was 

needed to document the results of monitoring efforts to characterize the quality of runoff from operating highways (Venner 

and others, 2004). Data from the current study, an earlier 
102 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 36. Statistics for concentrations of selected constituents estimated on the basis of the concentration of suspended sediment 

for three particle-size ranges in 105 samples of highway runoff and for concentrations of the constituents measured in samples 

of suspended sediment for equivalent particle sizes collected from the principal highways in Massachusetts, and the differences

between the estimated concentrations and the measured concentrations in composite samples of highway runoff.

[<, less than the value shown; >, greater than the value shown; mm, millimeters in diameter]

Constituent Statistic

Percent associated 

with particles

of diameter

< 0.063 mm

Percent associated

with particles

of diameter

between 0.063

and 0.250 mm

Percent associated 

with particles

of diameter

> 0.250 mm

Difference between 

estimated

constituent

concentrations

and measured

concentrations in 

composite samples 

of highway runoff 

(percent)

Phosphorus 25th percentile 77.6 1.3 1.8 -66

Median 89.3 4.4 5.4 -43

75th percentile 94.7 10.0 9.3 -2

Average 83.7 7.0 9.3 -28

Chromium 25th percentile 20.0 5.0 10.3 -51

Median 52.6 10.5 22.3 -2

75th percentile 82.9 24.9 48.2 104

Average 50.8 18.5 30.7 104

Copper 25th percentile 78.4 1.0 1.6 -76

Median 91.1 4.0 4.0 -57

75th percentile 95.8 10.6 9.1 -20

Average 84.8 7.3 7.9 -45

Iron 25th percentile 65.8 3.1 3.9 -30

Median 81.2 6.1 11.2 -15

75th percentile 91.1 12.9 20.5 4

Average 75.0 9.0 15.9 -8

Lead 25th percentile 82.5 0.8 1.2 -44

Median 92.4 2.5 3.4 -21

75th percentile 96.6 7.7 6.6 -6

Average 87.6 5.7 6.8 -20

Manganese 25th percentile 68.0 2.4 3.0 -60

Median 83.8 6.6 8.6 -32

75th percentile 92.0 12.0 18.0 3

Average 77.6 8.8 13.6 -23

Nickel 25th percentile 63.6 2.9 3.6 -77

Median 80.6 6.3 10.5 -58

75th percentile 90.7 13.2 21.0 -41

Average 75.3 9.3 15.4 -53

Zinc 25th percentile 86.6 1.0 0.9 -81

Median 94.3 2.8 2.1 -69

75th percentile 97.5 6.7 5.4 -46

Average 89.5 5.4 5.1 -60
Summary and Conclusions 103

Massachusetts highway-runoff study (Smith, 2002), and other 

highway-runoff studies (for example, Hardee and others, 

1978; Harned, 1988; Waschbusch, 2003) are available from 

the USGS National Water Information System Web (NWIS 

Web). The NWIS Web format, however, does not facilitate 

use of the data with the SELDM model, and the NWIS Web 

database does not include data collected by organizations other 

than the USGS. As such, Version 1.0.0a of the HRDB database 

will be archived with this report at the USGS Publications 

Warehouse (available on the web at: http://pubs.usgs.gov) to 

document currently available highway-runoff data in a format 

that facilitates use of the data with SELDM. A copy of the 

HRDB documentation, the data dictionary, and the database 

design plate (Granato and Cazenas, 2009) are on the CD-ROM 

accompanying this report to facilitate use of the HRDB.

The summary in figure 28 provides an overview of the 

complete HRDB version 1.0.0a data set that is currently available for analysis of highway-runoff quality. Currently, the 

database includes data from 9 highway-runoff data sets with 

117 stations, 4,186 storms, and 54,383 individual stormwaterquality measurements. Data from the 1990 FHWA runoff-quality model “working database,” which represents a compilation of previous studies (Driscoll and others, 1990a; b), are 

included to supplement and to provide a basis for comparison 

with newer data sets. The California data set (CA 2003) currently is one of the largest highway-runoff data sets collected, 

processed, analyzed, and recorded in a robust and consistent 

data-quality system (California Department of Transportation, 

Office of Environmental Engineering, 2000, 2002, 2003a, 

2003b, 2003c, 2003d, 2004). Highway-runoff data from Massachusetts represent results from this investigation (MA 2009) 

and the BMP characterization study (MA 2002). The Michigan 

Department of Transportation data (MI 1998) are results from 

a highway stormwater-runoff characterization study (CH2MHill, Inc., 1998). The Ohio data (OH 1997) are results from 

a small highway stormwater-runoff characterization study in 

Cincinnati, Ohio (Sansalone and Buchberger, 1997; Sansalone 

and others, 1997). The Texas data set represents results from 

a characterization study (Barrett and others, 1995, 1996) and 

a BMP study (Walsh and others, 1997). The Washington State 

data sets include highway runoff characterization data for 

NPDES permits (Tetra Tech, Inc., 2002, 2003, 2004; Washington State Department of Transportation, Environmental 

Services Office, 2001, 2002, 2003, 2004) and BMP monitoring 

data (Taylor Associates, Inc., 2002a, 2002b). The Wisconsin 

study (Waschbusch, 2003) documents highway-runoff quality with and without street sweeping. The current data set 

(MA 2009) represents about 11 percent of the sites, 36 percent 

of the storm events, and about 27 percent of the EMC values 

in version 1.0.0a of the HRDB (fig 28). Combined, the two 

Massachusetts studies (MA 2002 and MA 2009) represent 

about 14 percent of the sites, 43 percent of the storm events, 

and 29 percent of the EMC values in the database. The storm 

events in the highway-runoff database span a period of more 

than three decades from 1975 to 2007 (fig. 29). The two Massachusetts studies (MA 2002 and MA 2009) represent current 

conditions in Massachusetts.

Summary and Conclusions

The USGS, in cooperation with FHWA and the Massachusetts DOT, began a study in September 2004 to characterize the quality of highway runoff for a wide range of constituents for selected highways in Massachusetts with AADT 

volumes ranging from about 3,000 to more than 190,000 

vehicles per day. Highway-monitoring stations were installed 

at 12 locations on 8 highways throughout the State of Massachusetts. The highway-monitoring stations were selected 

on the basis of published AADT volumes; proximity to each 

other; similarities in surficial geology, soils, vegetation, and 

land use as a function of USEPA level III ecoregions; highway and drainage construction; site accessibility and safety; 

and suitability for hydrologic and meteorologic monitoring 

and collection of stormwater samples. The 12 stations were 

subdivided into four primary, four secondary, and four test 

stations. Paired primary and secondary stations were located 

within a few miles of each other on a limited-access section 

of the same highway to ensure comparable levels of traffic 

volume and density. Although both the design and operation 

of the primary and secondary monitoring stations were similar, 

the monitoring period and number of samples of highway 

runoff collected at the primary station were greater than at 

the secondary stations. Most of the stormwater samples were 

collected at the primary and secondary stations, which were 

located on four principal highways in the eastern region of the 

State. Samples of stormwater collected at the test stations were 

used to assess the transferability of the data collected from 

the principal highways to other highways with characteristics 

that differ in construction, land use, and geography from the 

principal highways.

Methods

Automatic-monitoring techniques were used extensively 

to collect continuous measurements of water level, water temperature, specific conductance, air temperature, and rainfall, 

and to collect composite samples of highway runoff. Runoff 

coefficients were computed on the basis of the drainage areas, 

and flow and rainfall records for each storm for which data 

were available. Event-mean specific conductance values were 

calculated for each highway site on the basis of calculated 

values of discharge greater than 0.009 ft3

/s and corresponding measurements of specific conductance to supplement and 

expand the number of event-mean values of specific conductance. Additionally, EMCs for dissolved Ca, Cl, Na, and SO4

were estimated on the basis of the event-mean specific conductance values with the adjusted superpositioning technique 

for most monitoring stations.
104 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Figure 28. Summary of the highway-runoff data including (A) a count of sites, storms, and event-mean concentration 

values in the database, and the percentage of (B) sites, (C) storm events, and (D) event-mean concentration values in each 

highway-runoff data set. (FHWA, Federal Highway Administration)

A Count of sites, storm events, and 

 event-mean concentration values

B Percentage of sites in each data set

C Percentage of storm events in 

 each data set

D Percentage of event-mean 

 concentration values in each data set

Federal:

FHWA 1990

State: 

CA 2003

MA 2002

MA 2009

MI 1998

OH 1997

TX 1997

WA 2005

WI 2000

Sum

24

52

4

13

3

1

6

12

2

117

937

981

285

1,523

9

13

187

155

96

4,186

8,428

26,104

1,236

14,563

198

169

1,925

1,486

725

54,384

Storms EMC Highway-Runoff

Data Set Sites

Count of

CA 2003

44.4%

MA 2002

3.4%

MA 2009

11.1% MI 1998

2.6%

OH 1997

0.9%

TX 1997

5.1%

WI 2000

1.7%

WA 2005

10.3%

FHWA 1990

20.5%

CA 2003

23.4%

MA 2002

6.8%

MA 2009

36.4%

MI 1998

0.2%

OH 1997

0.3%

TX 1997

4.5%

WI 2000

2.3%

WA 2005

3.7%

FHWA 1990

22.4%

CA 2003

47.6%

MA 2002

2.3% MA 2009

26.6%

MI 1998

0.3%

OH 1997

0.3%

TX 1997

3.5%

WI 2000

1.3%

WA 2005

2.7%

FHWA 1990

15.4%
Summary and Conclusions 105

Figure 29. Temporal distribution of storm sampling dates for each data set in the highway-runoff database.

WI 2000

WA 2005

TX 1997

OH 1997

MI 1998

MA 2009

MA 2002

FHWA 1990

CA 2003

N = 1,523 

N = 13 

N = 96 

N = 155 

N = 187 

N = 9 

N = 285 

N = 937 

HIGHWAY-RUNOFF DATA SET

STORM SAMPLING DATE

N = 981 

1/1/1975 1/1/1980 1/1/1985 1/1/1990 1/1/1995 1/1/2000 1/1/2005

EXPLANATION

N Number of observations 

Storm event

Approximately 140 flow-weighted samples were collected automatically during rain and mixed precipitation 

storms at the 12 monitoring stations from September 2005 

through September 2007 and analyzed for concentrations 

of selected dissolved major ions, total N and P, selected 

total-recoverable metals, suspended sediment, and SVOCs. 

Samples of highway runoff were collected year-round during 

storms with various antecedent dry periods throughout the 

2-year sampling period. The distribution of the duration of dry 

antecedent periods, as well as the distribution of event-mean 

specific conductance values, for storms during which samples 

were collected at each of the principal highways was similar to 

the distribution of both of these conditions during the monitoring period. Precipitation totals ranged from about 0.1 to 5.1 in. 

for storms that were sampled at the principal highways and 

most precipitation totals for sampled storms were within the 

interquartile range of precipitation totals greater than 0.10 in. 

recorded from 1967 through 2007 by the National Climatic 

Data Center near Worcester, Massachusetts.

In addition to the collection of samples of highway 

runoff, samples of other media were collected to supplement 

the data set and support data analysis. These media include 

sieved highway-runoff sediment from the principal highways, and background soils, berm materials, maintenance 

sands, deicing compounds, and vegetation matter collected 

near or on the highway. Most of these samples were analyzed 

for 32 elements. Samples of sieved highway-runoff sediment and vegetation matter also were analyzed for selected 

PAHs and TOC.

Data Quality

The accuracy and precision of the data collected in this 

study were ensured by making quality-control measurements 

at each of the monitoring stations, operating redundant sensors, conducting quality-assurance experiments, and collecting various types of quality-control samples. Quality-control 

samples of artificial and blank water were collected to identify 

potential bias in sampling and processing methods and contamination resulting from the sampling equipment and from 

the sample collection, processing, and analysis. Other qualitycontrol samples were collected in the field and laboratory to 

estimate analyte degradation, analytical-method recovery and 

performance, and presence of interfering agents.

Comparative measurements made during site visits at 

each of the highway-monitoring stations indicate that the 

continuous measurements of water level, water temperature, 

and specific conductance recorded by the monitoring stations 

were generally accurate and precise. Despite the sometimes 

large variability in runoff coefficients, the agreement between 

values of event-mean specific conductance estimated from 

continuous records of flow and specific conductance, and 

the measured specific conductance of flow-weighted water 

samples indicate that flows calculated from a stage-discharge 

relation for each monitoring station were reasonable. This also 

indicates that the frequency of sample collection within storms 

was sufficient to accurately characterize the variability of the 

quality of runoff during the storms. Experimental results indicate that concentrations of suspended sediment with diameters 

ranging from 0.250 mm to about 6.0 mm in water samples 
106 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

collected by an automatic sampler in conjunction with the 

static-mixer assembly reasonably represent the distribution of 

particle sizes in an artificial flow stream over a range of flows. 

However, a comparison of measurements of suspended sediment greater than 0.250 mm in diameter collected at the end 

of the highway discharge pipe and in flow-weighted composite 

samples of runoff from one of the primary monitoring stations 

indicates that there is a potential positive bias associated with 

concentrations of coarse particles in samples of water collected using automatic-sampling methods in this study. The 

bias observed for the environmental samples could, in part, 

result from the automatic sampler disproportionally collecting 

natural organic materials, which are less dense than mineral 

sediments and relatively abundant. Considering that the concentration of P in natural organic matter is high compared to 

the concentration of metals, the concentrations for P also may 

be elevated in samples of highway runoff, particularly during 

the growing season.

Results of analyses of sample volumes reduced through 

splitting indicate that concentrations of suspended-sediment 

particles less than 0.063 mm in diameter in the subsamples of 

the sediment/water mixture were both accurate and precise. 

Analysis of field-blank data indicates that the cleaning and 

preparation of sampling equipment, sample processing, and 

respective analytical methods were not a source of contamination bias for most constituents. With the exception of naphthalene, contamination bias appeared to be random for all 

constituents. Low-level measurements for naphthalene in field 

blanks are believed to be from contaminated source water.

Analysis of replicate samples for selected PAH and 

phthalate compounds and spike recoveries in fortified 

environmental samples analyzed for PAH, phthalate, and 

other anthropogenic organic and natural organic compounds 

indicate that the measured concentrations for most of these 

constituents are reasonably precise and that field and laboratory processing, analytical method performance, and sample 

matrix effects for the constituents are not a large source 

of bias for most constituents. The average spike recoveries for both PAH and phthalate compounds were similar 

to the average laboratory-preparation spike recoveries for 

the respective compounds for the study period, except for 

benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, bis(2-ethylhexyl) 

phthalate, and di-n-butyl phthalate, which were notably lower. 

Because the variability of field-spike recoveries for these compounds was similar to the variability of the respective laboratory preparation-spike recoveries and because the replicate 

field-spike recoveries for these compounds were relatively 

precise, such differences are likely attributable to degradation 

of the compounds prior to laboratory processing or matrix 

effects that mask the respective compounds. As a result, these 

data indicate that concentrations of these four compounds are 

likely underestimated for samples of highway runoff collected 

in this study.

Standard-reference samples were submitted to laboratories to identify potential contamination bias and to assess 

analytical method performance. Samples were analyzed 

for both total and total-recoverable concentrations, in part, 

because reference materials are certified only for total concentrations. Concentrations of P and selected metals also were 

determined in reference-material water mixtures. Median 

total concentrations in blind samples for about 40 percent of 

the measured elements, for which there were certified concentration values for standard reference soil, were within the 

certified concentration ranges. The median concentrations for 

blind samples of the measured elements, for which there were 

noncertified values, were generally less than, but within 20 

percent of, the noncertified values. The median total-recoverable concentrations of elements in NIST reference material 

samples were within the reported range of recovery, except 

those for As, La, and P. Total-recoverable concentrations of 

selected elements, except Cu and Pb, measured in artificial 

samples of water were lower than the respective measurements 

made by the USEPA method 3050B in samples of solid media. 

Concentrations of total-recoverable Cr, Fe, Ni, P, and Zn in the 

artificial water samples were lower than the lower recovery 

limit of the reference material. These quality-control data were 

used as a basis to adjust the concentrations of constituents in 

solid media when comparisons were made with whole-water 

concentration data.

Replicate samples of background soils, highway-berm 

soils, suspended sediment, and other miscellaneous samples 

were collected to determine the precision of the data. The 

average absolute RPD was less than 10 percent for all 

elements, except for As, Na, Pb, Sc, and Ti. For these elements, the average absolute RPD between replicate pairs 

ranged from about 11 to 16 percent. The variability observed 

in the concentrations of elements in replicate pairs could be, in 

part, a result of differences in the distribution of particle sizes 

in the samples. The median RPD between the amount of material in particle-size classes less than 0.063 mm in diameter, 

between 0.063 mm and 0.250 mm in diameter, and greater 

than 0.250 mm in diameter for 16 replicate pairs was 7, 8, and 

4 percent, respectively.

Quality of Highway Runoff

The data presented in this report represents the quality of 

stormwater runoff from highways with AADT volumes ranging from about 3,000 to more than 190,000 vehicles per day at 

12 locations on 8 highways throughout the State of Massachusetts. These data were analyzed to determine the appropriate 

aggregation for individual data sets to estimate planning-level 

highway contributions for the constituents presented in this 

study for other highways in Massachusetts.

 Evaluation of Highway Runoff

Highway-runoff data, including populations of concentrations of selected dissolved major ions, total nutrients, 

total-recoverable metals, PAHs, phthalates, and suspended 

sediments (including particle size) were evaluated using the 
Summary and Conclusions 107

nonparametric Mann-Whitney test. Mann-Whitney tests were 

used to determine significant differences between sample 

populations collected from the same highways, but at different locations, and to determine significant differences between 

sample populations collected from different highways, but 

with similar AADT volumes. Similar statistical methods also 

were used to test for differences between the populations of 

sample concentrations among the four principal highways that 

differed mainly by traffic volume. Sample concentrations that 

were not detected or were estimated to be below the LTMDL 

were set equal to a value less than the LTMDL for each 

constituent evaluated. Analyses for many PAH and phthalate 

compounds were not performed because these compounds 

were consistently undetected in samples or because all of the 

concentrations were estimated to be below the LTMDL.

With a few exceptions, test results between paired populations (that is, data from the primary and secondary stations 

on each principal highway) show that concentration data generally are not statistically different at a 95-percent confidence 

interval, indicating similarities between populations. Results 

of tests between populations of concentrations of suspended 

sediment and (or) concentrations of suspended sediment less 

than 0.063 mm in diameter show that populations of concentrations are significantly different for the stations on Route 

119 and Interstate 495. These differences are believed to be 

the result of runoff patterns and berm conditions associated 

with the secondary monitoring station that differed from the 

primary monitoring station for each highway. Also, results of 

tests between populations of concentrations of total-recoverable Zn for the stations on Route 2 show that populations of 

concentrations are significantly different (p value less than 

0.05). Unfortunately, this difference is not fully explainable 

with available data.

Concentration data collected from the test highways were 

compared to concentration data collected from the principal 

highways of similar AADT volumes to determine whether the 

data were transferable from highway to highway on the basis 

of AADT volume. Where sufficient concentration data were 

available for testing, no significant differences were found 

between populations of concentrations of selected dissolved 

major ions, total nutrients, total-recoverable metals, PAHs, 

phthalates, and suspended sediments (including particle size) 

in composite samples of highway runoff collected from the 

stations on Route 119 and Route 8 (highways with the lowest 

AADT volumes), and the only significant difference observed 

in test results between populations of constituent concentrations for the stations on Route 2 and Interstate 190 (highways 

with moderate AADT volumes) was for total-recoverable Zn. 

As previously discussed, the significant difference between 

the populations of total-recoverable Zn concentrations may 

be attributable to the high concentrations (median value of 

308 μg/L) determined for the primary monitoring station on 

Route 2. In contrast, results of many tests between populations of constituent concentrations collected from the sites on 

Route 2 and Interstate 195 (highways with moderate AADT 

volumes) were significant at a 95-percent confidence interval. 

Test results between populations of dissolved concentrations 

of Ca and K; concentrations of total P; and total-recoverable 

concentrations of Cd, Cr, Cu, Mn, and Zn from Route 2 and 

Interstate 195 were significant at a 95-percent confidence 

interval. Test results between populations of concentrations of 

total N; dissolved Mg, Na, Cl, and SO4

; total-recoverable Cu, 

Fe, Pb, and Ni; suspended sediment; and PAH and phthalate compounds, where sufficient data were available, were 

not significant at a 95-percent confidence interval. Results 

of many tests between populations of constituent concentrations in composite samples of highway runoff collected from 

stations on Interstate 95 and Interstate 93 (highways with very 

high AADT volumes) also were significant. Concentrations of 

most total-recoverable metals in samples of highway runoff 

collected from Interstate 93 were considerably higher than the 

respective concentrations measured in samples from Interstate 

95. Results for Mann-Whitney tests between populations 

of concentrations of total-recoverable metals, except for Cd 

and Ni, and suspended sediment collected from the stations 

on Interstate 95 and on Interstate 93 were significant at the 

95-percent confidence interval. No significant differences were 

found between populations of concentrations of total nutrients, 

major ions, and PAH and phthalate compounds.

The significant differences between many of the populations of metal concentrations for Route 2 and Interstate 195, 

and for Interstate 95 and Interstate 93, in part, could be due 

to the effect of local soil deposition on the highway surfaces. 

The concentrations of many metals in samples of soil collected near Interstate 195 were substantially lower than the 

concentrations of those metals in samples of soil collected 

near Route 2. Likewise, the concentrations of many metals in 

samples of soil collected near Interstate 93 were substantially 

higher than the concentrations of the same constituents collected in samples of soil near Interstate 95. The differences in 

the test results are, in part, a function of the local soil chemistry near each of the highways, given the dissimilar enrichment 

of metal concentrations measured in the samples of soil. However, though this may help to explain the higher concentrations 

of Cu, Pb, and Zn in samples of highway runoff collected from 

Interstate 93, concentrations of other metals in soil samples 

collected near Interstate 93 were similar to the concentrations in soil samples collected near the other highways. The 

nearly order-of-magnitude higher concentration of suspended 

sediment measured in samples of highway runoff collected at 

Interstate 93 is likely the main factor in the difference between 

the populations of concentration data for many of the totalrecoverable metals for the two highways. High rates of dry 

deposition, which are commonly reported for urbanized areas 

containing large impervious areas, also could explain the significant difference between concentrations of suspended sediment measured for Interstate 93. These data indicate that the 

quantity, as well as the quality, of sediment in highway runoff 

can be affected by the proximity of the site to highly urbanized 

areas containing large amounts of impervious area.

Populations of concentration data collected for each 

principal highway were compared to the populations of 
108 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

concentration data collected for each of the other principal 

highways to determine whether the populations are significantly different from highway to highway. Most of the MannWhitney test results indicate that the data collected for the 

principal highway on Route 119, which had the lowest AADT 

volume, are significantly different at a 95-percent confidence 

interval from data collected for the other three principal highways. Results for paired tests between populations of concentrations of dissolved Cl, Na, and Mg; benzyl n-butyl phthalate; and di-n-butyl phthalate for Route 119 and each of the 

other principal highways are not significant at the respective 

confidence interval. Results for paired tests for concentrations 

of suspended sediment were not significant for any of the principal highways other than Route 119. Only a handful of test 

results indicate a significant difference between populations of 

constituent concentrations among the three larger highways. 

Concentrations of dissolved Ca were significantly different for 

all paired tests of data from Interstate 95. The highway-monitoring stations on Interstate 95 were located in a section of 

highway designated as a low-salt area because of its proximity 

to a major drinking-water-source area; thus, the significant 

difference between concentrations of Ca for Interstate 95 and 

the other highways is likely a function of the more widespread 

use of liquid calcium chloride for winter highway maintenance 

on Interstate 95.

Relation of Constituents to Annual Average Daily 

Traffic Volume

Although the populations of concentrations of most 

constituents were not significantly different among the three 

larger highways, the median concentrations and upper interquartile ranges for many total-recoverable metals collected 

from the 12 monitoring stations increased with increasing 

AADT volumes, indicating a positive correlation between 

the two variables. The frequency of detection for various 

organic compounds also increased with traffic volume for the 

four principal highways. Results for Kendal’s Tau correlation 

coefficient and Spearman rank correlation coefficient tests for 

all highways indicate that correlations between the median 

concentrations of total N, total P, all total-recoverable metals, benzo[a]anthracene, benzo[b]fluoranthene, fluoranthene, 

and pyrene and AADT volumes are significantly different 

at a 95-percent confidence interval. Spearman rank correlation coefficient test results for benzo[a]anthracene and 

benzo[b]fluoranthene are not significant at a 95-percent 

confidence interval; however, correlations between the median 

concentrations of these constituents and the AADT volumes 

are significantly different at slightly lower confidence intervals. Test results for concentrations of dissolved Cl, Na, Ca, 

Mg, K, and SO4

; benzo[a]pyrene; Bis(2-ethylhexyl) phthalate; 

chrysene; di-n-octyl phthalate; and suspended sediment are 

not significant at confidence intervals greater than 89 percent 

for either test; therefore, AADT volumes may be a poor predictor for concentrations of these constituents in the absence 

of additional data.

Highway Winter Maintenance Materials and 

Data Seasonality

Concentrations of Ca, Cl, Na, and SO4, which are the 

major constituents of road salt, were estimated using the 

adjusted superposition technique over the full range of 

flow-weighted measurements of specific conductance for all 

available data, including snowmelt events, collected at 11 

highway-monitoring stations. These 1,381 estimated concentrations provide a nearly order of magnitude increase in 

data density over water-sample data collected during this 

study. The estimated data from this study indicate that less 

than about 2 percent of the event-mean concentrations of Cl 

exceed 10,000 mg/L, and about 20 percent of the event-mean 

concentrations exceed 230 mg/L (the USEPA freshwater 

aquatic life criteria).

Concentrations of nearly all constituents measured in 

samples of highway runoff in this study increased substantially in composite samples collected during the winter months 

compared to the concentrations in non-winter composite 

samples. Average concentrations of total P, total-recoverable 

metals, and suspended sediment in samples of highway runoff 

collected from the principal highways during the winter were 

about 3 to 11 times greater than the average concentrations in 

samples of non-winter runoff. Changes in ambient temperature, differences in driving methods, snow removal operations, 

and the presence of snow embankments along the highways 

potentially affect winter concentrations of metals and organic 

compounds measured in this study. Results of the single-tail 

Mann-Whitney test indicate that the concentrations of nearly 

all constituents measured in composite samples collected 

during the winter were significantly higher at a 99-percent 

confidence interval than the concentrations of constituents 

measured in composite samples collected during the nonwinter months. The use of deicing compounds, which contain 

trace amounts of N and total-recoverable metals, does not fully 

explain the significant differences observed between winter 

and non-winter concentrations of each of the constituents. 

Ratios for nitrate and total-recoverable metals associated with 

road salt and calcium chloride to Cl are estimated to account 

for only a small fraction of the increase in overall concentrations from non-winter levels. However, many of the same 

constituents were measured in samples of winter maintenance 

sands, and although the concentrations of these constituents 

in the sand were small, the amount of sand applied to the 

highways during the winter increased the concentrations of 

suspended sediment by as much as an order of magnitude. 

The contribution of P and total-recoverable metals from the 

application of maintenance sand was estimated on the basis 

of the average increase in the concentration of suspended 

sediment during winter storms and on the basis of the average 

concentrations of P and total-recoverable metals in samples of 
Summary and Conclusions 109

highway-maintenance sand. Data on concentrations of several 

elements estimated on the basis of stormwater EMCs in 

samples collected on Interstate 495 and highway-maintenance 

sand indicate that highway-maintenance sand accounts for 

about 94, 7, 38, 53, 15, 9, and 2 percent of the increase in 

the winter concentrations of P, Cu, Fe, Mn, Ni, Pb, and Zn, 

respectively. The increase in the difference between winter 

and non-winter concentrations of these constituents is likely 

greater for smaller highways, such as Route 119, because such 

highways have similar levels of winter maintenance and lower 

non-winter stormwater concentrations of the same constituents. Other winter conditions have the potential to increase 

concentrations of many constituents in runoff. Low ambient 

temperatures can affect volatilization rates for SVOCs and 

increase engine emission rates. Poor winter driving conditions 

affect vehicle operations and can increase the rate of wear for 

vehicle components as well as the highway surface, and snow 

banks can entrain large amounts of highway-related particles 

near the shoulder that subsequently can wash onto the highway surface.

Comparison of Historical Data and Concurrent 

Data Sets

Comparisons of data collected during this study with data 

in other published data sets can provide useful information for 

identifying compositional differences and trends in concentrations of highway-related constituents in highway runoff. In 

this study, the median concentrations of dissolved Cl, total N, 

and total-recoverable P, Cd, Cr, Cu, Fe, Pb, and Zn in samples 

collected from highway sites with AADT volumes of 30,000 to 

85,000 vehicles (Interstate 190, Interstate 195, Interstate 495, 

and Route 2) were compared to median concentrations in other 

published data sets containing data collected from highways of 

similar AADT volume. With the exception of dissolved Cl, the 

median concentrations of nutrients and total-recoverable metals in this study were much lower than the respective median 

concentrations in the historical data collected by the FHWA 

from 1976 to 1984. These data indicate that concentrations of 

total P and many total-recoverable metals in highway runoff, 

particularly Cd and Pb, are substantially lower than the historical concentrations from the 1970s and 1980s, despite the fact 

that total vehicle miles have increased. Favorable comparisons 

with more recent studies indicate that some concentration data 

collected in other states could be used to supplement the data 

collected in this study.

Sources of Highway-Runoff Constituents

Identification of individual sources of specific constituents is difficult because many highway-related constituents 

coexist in a wide variety of both natural and anthropogenic 

materials deposited on highways. The proportions of most 

highway constituents attributable to likely sources were 

estimated from ratios of certain PAH compounds and from 

ratios of the dominant particulate-associated PAHs to selected 

elements. For example, the median ratios for all concentrations of An/(An+Phe) in composites of runoff from each 

highway in this study are synonymous with the ratios reported 

for gasoline-engine emissions. In contrast, the median ratios 

for winter concentrations of An/(An+Phe) in composites of 

highway runoff during, or shortly after, winter plowing operations of the principal highways decreased, likely indicating 

that the dominant source of the PAHs shifted from gasolineengine emissions to asphalt wear. The median ratios for 

concentrations of Fl/(Fl+Py) and Ba/(Ba+Chr) in composites 

of highway runoff in this study also were similar to ratios for 

emissions from gasoline and diesel engines.

The median concentrations of total P and most trace elements measured in composite samples of highway runoff from 

each principal highway were compared to estimated concentrations expected from automobile emissions. Concentrations 

of the above constituents in exhaust were estimated on the 

basis of the average ratio of the reported emission rates 

for each constituent to the emission rates for chrysene and 

indeno[1,2,3-cd]pyrene. Assuming the dispersion of both trace 

metals and PAHs associated with exhaust particles is similar, 

exhaust emissions account for only a small fraction of metals 

measured in samples of highway runoff. Ratios of median 

EMCs of P and total-recoverable Cu, and Fe to average metal 

concentrations associated with concentrations of chrysene and 

indeno[1,2,3-cd]pyrene indicate that less than 3 percent of 

the constituents are accounted for by exhaust emissions from 

gasoline engines. Similar ratios for median concentrations for 

total-recoverable Cr, Mn, Ni, Pb, and Zn indicate that about 4 

to 13 percent of the respective constituents are accounted for 

by exhaust emissions from gasoline engines.

Atmospheric deposition also can affect the quality of 

highway runoff. Concentrations of major ions in precipitation 

do not constitute a large fraction of the major ions in samples 

of highway runoff in Massachusetts, except for Mg and SO4

. 

Concentrations of Mg and SO4

 in precipitation account for 

about 10 and 21 percent, respectively, of the mean concentrations in non-winter highway runoff for Interstate 95, and concentrations of NH4

 and NO3 in precipitation account for about 

55 percent of the mean concentrations of total N in all samples 

collected on Interstate 95 in this study. Concentrations of total 

N in precipitation potentially constitute a greater percentage of 

the concentrations in highway runoff from the other principal 

highways because the concentrations of total N in samples of 

highway runoff from those sites were lower.

Local soils and highway-berm soil can contribute much 

of the suspended sediment entrained in highway runoff. As 

discussed earlier, adjacent soils deposited on the surface of 

the highway can affect the composition of, and concentrations of many elements in, highway runoff. Contributions 

of many of the total-recoverable metals in background soils 

were estimated on the basis of the median concentration of 

suspended sediment in composite samples of highway runoff 

from the principal highways along with median concentrations of the same total-recoverable metals in samples of local 
110 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

soil collected near the primary highway-monitoring stations. 

These estimates indicate that background soils account for 

on average about 37 percent of the median P concentration, 

100 percent of the median Cr concentration, 4 percent of the 

median Cu concentration, 53 percent of the median Fe concentration, 54 percent of the median Mn concentration, 15 percent 

of the median Ni concentration, 44 percent of the median Pb 

concentration, and 2 percent of the median Zn concentration in 

samples of runoff from the principal highways. The contributions of the elements to concentrations in whole water samples 

are likely conservative, excluding Cr which is overestimated, 

because the values were estimated without regard to the 

distribution of the particle sizes for background soils and total 

concentrations of suspended sediment. The concentrations of 

many elements in berm materials composed of native soils, 

winter maintenance materials, and other anthropogenic particles also can affect the quality of highway runoff. Data from 

this study indicate that the distributions for concentrations of 

Cu, Fe, Mn, Ni, P, Pb, and Zn in highway-berm soils and for 

normalized concentrations of these constituents in suspended 

sediment often overlap. These data indicate that erosion or 

mechanical transport of highway-berm soils onto the paved 

surface could be a large source of P and several total-recoverable metals in samples of highway runoff.

The mass of Cu, Zn, and phthalate compounds measured in samples of highway runoff is only partially, if at 

all, accounted for by the application of deicing compounds, 

exhaust emissions, soils, and berm materials. Tire and brake 

wear appears to be the dominant source of these constituents 

on the basis of the composition and wear rates for these items 

reported elsewhere in the literature.

For 15 samples of highway runoff collected from the 

principal highways and from Interstate 93, an additional 62 

organic compounds that include nonionic surfactants, caffeine, 

plant sterols, flame retardants, trace compounds associated 

with fecal bacteria, wood preservatives, gasoline and diesel 

fuels, antioxidants, and personal care products were included 

in the sample analysis. For these 15 samples, 45 of the 62 

compounds were detected at least once, and 23 compounds 

were detected at concentrations greater than the laboratory 

LTMDL. Anthraquinone, bisphenol A, camphor, and cholesterol were the most frequently detected compounds. Although 

most compounds were detected less frequently in samples of 

highway runoff collected on Route 119 (the most rural highway with the lowest AADT volume) than in other samples, the 

frequency of detection generally was similar among highways. 

About one-third of the compounds that were detected are 

likely attributable to fuels, lubricants, antifreeze, windshield 

fluids, chemical treatments of the engine compartments, finish 

coats, panels, and other vehicle components. Other compounds 

detected in samples of highway runoff indicate the presence 

of plant materials, fecal bacteria, and potential leachates from 

highway litter.

Suspended Sediment as a Surrogate for 

Highway-Runoff Constituents

Suspended sediment can be a major transport mechanism 

for many constituents in highway runoff. Data collected in 

this study indicate that highway suspended sediment contains 

relatively high concentrations of P, trace elements, PAHs, and 

phthalates. These analyses also indicate that, in many cases, 

the fine fraction of sediment less than 0.063 mm in diameter 

often is more enriched in these constituents than the coarser 

sediment fractions. Concentrations of suspended sediment for 

three particle-size ranges were examined as potential surrogates for concentrations of sediment-affiliated constituents 

measured in samples of highway runoff.

 Planning-level estimates for concentrations of total P and 

total-recoverable metals were made directly from the constituent concentrations in samples of sieved suspended sediment 

and from the concentrations of the three particle-size grades of 

suspended sediment in samples of highway runoff. Comparisons of these estimated P and total-recoverable metal concentrations with concentrations in whole-water samples indicate 

that it is possible to estimate reasonable planning-level loads 

for many constituents discharged from highways. For many 

applications, the average concentration for gradated concentrations of suspended sediment measured in composite samples 

of highway runoff in this study may be used in the absence of 

site-specific data because tests between most populations of 

concentrations of suspended sediment among the highways 

in this study, and tests between median concentrations of 

suspended sediment with AADT volume were not significantly 

different. Use of this method could have broad application and 

may provide useful information for the selection of BMP and 

for stormwater-monitoring applications.

Highway-Runoff Database

Data from this study are stored in Version 1.0.0a of the 

HRDB database, which is presented in the appendix of this 

report. The HRDB warehouse was created to document data 

and information from available highway-runoff monitoring 

studies. Version 1.0.0a of the HRDB database also contains 

data from an earlier Massachusetts highway-runoff study, and 

other highway-runoff studies conducted across the Nation 

since 1978. The HRDB application, which is the graphical 

user interface and associated computer code, can be used to 

facilitate estimation of statistical properties of runoff coefficients, runoff-quality statistics, and relations between waterquality variables in highway runoff from the available data. 

Thus, the HRDB application can serve as a data preprocessor 

for the Stochastic Empirical Loading and Dilution Model, 

which is designed to facilitate the estimation of runoff flows, 

concentrations of constituents, and loads of constituents from 

highways and in receiving waters at unmonitored sites on the 

basis of site characteristics.
References Cited 111

Data Application

In general, concentrations of many total-recoverable metals, PAHs, and phthalate compounds increase with increasing 

AADT volume and amount of urbanization or surrounding 

impervious area. Concentrations of all constituents measured 

in samples of highway runoff in this study increased significantly during the winter months. Increases in concentrations 

of total P and many total-recoverable metals in this study were 

specifically attributed to maintenance sands applied to the 

highways. Therefore, information on use and application rate 

for maintenance sands may be important to include in future 

studies of the quality of highway runoff. The geographic location of a given highway under study is important because the 

level of highway maintenance during the winter is different 

across Massachusetts because the climate away from the coast 

generally is cooler, and the highway grades tend to be steeper. 

Ancillary data, collected as part of this study, also indicate that 

soil chemistry can affect the base concentration of total P and 

many total-recoverable metals in samples of highway runoff. 

As a result, the quality of highway runoff can differ within the 

natural features of the State. Mobilization of these soils, either 

from vehicles that track materials onto the road surface or 

from erosion of adjacent highway shoulders, can cause large 

increases in constituent concentrations. The data presented 

in this report represent the typical quality of highway runoff 

discharged through catch basins for eight Massachusetts highways over a large range of AADT volumes. Concentrations 

in highway runoff for the constituents reported in this study 

may be different for other highways within the State that have 

different levels of winter maintenance activity, or additional 

BMPs within the drainage system, or that have site characteristics that were previously identified to affect runoff quality.

Acknowledgments

The author expresses his gratitude to Henry L. Barbaro 

of the Massachusetts DOT, Environmental Services Division; Larry Salvatore and Mark J. Moore, Massachusetts DOT 

District 1; Paul Hoey and Ann Sullivan, Massachusetts DOT 

District 3; Brett Loosian, Massachusetts DOT District 4; and 

Roy Fierra, Massachusetts DOT District 5 for providing logistical support, including site selection, highway-site maintenance and repair, and periodic traffic control.

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Tables 16–21 119

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Begin time 

(hrmn)

End date 

(mm/dd/yyyy)

End time 

(hrmn)

Total

precipitation

(inches)

Total storm 

volume

(cubic feet)

Runoff

coefficient

(percent)

Route 119 -P 424209071545201 09/15/2005 0602 09/15/2005 1659 0.11 286 120

Route 119 -P 424209071545201 09/29/2005 1357 09/29/2005 1532 1.94 3,760 89

Route 119 -P 424209071545201 10/22/2005 2107 10/23/2005 0111 0.96 6,520 314

Route 119 -P 424209071545201 10/24/2005 2007 10/25/2005 1028 1.95 2,060 49

Route 119 -P 424209071545201 01/11/2006 2040 01/11/2006 2344 0.55 3,340 280

Route 119 -P 424209071545201 01/18/2006 0752 01/18/2006 1500 1.16 1,890 75

Route 119 -P 424209071545201 03/13/2006 2118 03/13/2006 2250 0.19 1,390 338

Route 119 -P 424209071545201 05/09/2006 1705 05/10/2006 0617 0.52 436 39

Route 119 -P 424209071545201 06/01/2006 2219 06/02/2006 0715 0.35 2,100 277

Route 119 -P 424209071545201 09/14/2006 1518 09/14/2006 2035 0.35 1,660 219

Route 119 -P 424209071545201 09/19/2006 1930 09/20/2006 0122 0.27 1,040 178

Route 119 -P 424209071545201 10/20/2006 0333 10/20/2006 1356 0.7 3,700 244

Route 119 -P 424209071545201 11/08/2006 0450 11/08/2006 2153 2.35 11,400 224

Route 119 -P 424209071545201 11/12/2006 1509 11/12/2006 1727 0.46 1,810 182

Route 119 -P 424209071545201 01/08/2007 0059 01/08/2007 1432 1.02 2,660 120

Route 119 -P 424209071545201 04/01/2007 2252 04/02/2007 0601 0.34 822 112

Route 119 -P 424209071545201 04/14/2007 1331 04/16/2007 0134 2.03 3,590 82

Route 119 -P 424209071545201 06/03/2007 1546 06/04/2007 2126 0.93 3,560 177

Route 119 -P 424209071545201 07/11/2007 2108 07/11/2007 2355 0.61 4,220 319

Route 119 -S 424155071543201 09/29/2005 1359 09/29/2005 1422 0.51 289 49

Route 119 -S 424155071543201 10/24/2005 2207 10/25/2005 0356 1.94 209 9

Route 119 -S 424155071543201 01/11/2006 2046 01/11/2006 2335 0.55 132 21

Route 119 -S 424155071543201 01/18/2006 1058 01/18/2006 1458 1.16 116 9

Route 119 -S 424155071543201 03/13/2006 2150 03/14/2006 0913 0.53 75 12

Route 119 -S 424155071543201 08/20/2006 0313 08/20/2006 0506 1.02 188 16

Route 119 -S 424155071543201 11/08/2006 1341 11/08/2006 2312 2.35 342 13

Route 119 -S 424155071543201 04/27/2007 0636 04/27/2007 0659 0.52 47 8

Route 119 -S 424155071543201 06/03/2007 1550 06/04/2007 1444 0.93 160 15

Route 119 -S 424155071543201 07/11/2007 2206 07/11/2007 2331 0.61 254 36

Route 119 -S 424155071543201 08/03/2007 1935 08/03/2007 1958 0.31 144 40

Route 8 -T 424019073062601 04/22/2006 1949 04/23/2006 1538 1.22 1,630 68

Route 8 -T 424019073062601 06/23/2006 2100 06/24/2006 0839 0.56 453 41

Route 8 -T 424019073062601 09/23/2006 0810 09/24/2006 1356 0.22 398 92

Route 8 -T 424019073062601 12/01/2006 1329 12/01/2006 1926 1.59 1,850 59

Route 8 -T 424019073062601 03/02/2007 1042 03/02/2007 1525 0.5 553 56
120 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Begin time 

(hrmn)

End date 

(mm/dd/yyyy)

End time 

(hrmn)

Total

precipitation

(inches)

Total storm 

volume

(cubic feet)

Runoff

coefficient

(percent)

Interstate 190 -T 423016071431501 08/14/2005 1736 08/15/2005 0757 0.92 960 50

Interstate 190 -T 423016071431501 09/29/2005 1416 09/29/2005 1459 0.36 196 26

Interstate 190 -T 423016071431501 10/07/2005 2345 10/08/2005 1142 5.09 3,320 31

Interstate 190 -T 423016071431501 10/22/2005 1831 10/23/2005 0004 1.33 784 28

Interstate 190 -T 423016071431501 10/24/2005 2148 10/25/2005 0620 2.73 1,900 33

Interstate 190 -T 423016071431501 03/13/2006 1237 03/13/2006 2340 0.49 249 24

Route 2 -P 423027071291301 09/15/2005 1007 09/15/2005 1315 0.25 172 72

Route 2 -P 423027071291301 09/29/2005 1449 09/29/2005 1613 0.43 292 71

Route 2 -P 423027071291301 10/22/2005 1927 10/23/2005 0038 0.57 1,530 280

Route 2 -P 423027071291301 10/24/2005 2222 10/25/2005 0545 1.08 4,170 404

Route 2 -P 423027071291301 01/11/2006 2045 01/12/2006 0333 0.48 375 82

Route 2 -P 423027071291301 01/18/2006 0910 01/18/2006 1843 0.81 554 72

Route 2 -P 423027071291301 03/13/2006 2245 03/14/2006 0214 0.63 1,340 222

Route 2 -P 423027071291301 05/09/2006 1530 05/10/2006 1250 0.93 1,220 137

Route 2 -P 423027071291301 06/02/2006 2021 06/04/2006 0152 2.86 4,290 157

Route 2 -P 423027071291301 06/23/2006 1617 06/23/2006 1914 1.03 656 67

Route 2 -P 423027071291301 08/20/2006 0331 08/20/2006 0824 1.00 954 100

Route 2 -P 423027071291301 08/27/2006 1450 08/28/2006 0413 0.84 512 64

Route 2 -P 423027071291301 09/19/2006 2100 09/19/2006 2351 0.67 778 121

Route 2 -P 423027071291301 11/07/2006 2203 11/08/2006 1450 1.57 4,930 328

Route 2 -P 423027071291301 01/08/2007 0455 01/08/2007 1645 0.88 1,170 139

Route 2 -P 423027071291301 03/02/2007 0413 03/02/2007 0711 -- 4,200 --

Route 2 -P 423027071291301 04/12/2007 1424 04/12/2007 1811 1.15 1,240 113

Route 2 -P 423027071291301 08/06/2007 1515 08/06/2007 1532 0.19 96 53

Route 2 -P 423027071291301 08/08/2007 0629 08/08/2007 0747 0.51 498 102

Route 2 -P 423027071291301 09/10/2007 2308 09/11/2007 0107 0.31 346 117

Route 2 -S 423027071291302 08/20/2006 0328 08/20/2006 0820 1 177 16

Route 2 -S 423027071291302 08/27/2006 1527 08/27/2006 2219 0.84 283 30

Route 2 -S 423027071291302 09/19/2006 2059 09/19/2006 2355 0.67 599 79

Route 2 -S 423027071291302 12/01/2006 1618 12/01/2006 2127 0.5 456 81

Route 2 -S 423027071291302 01/08/2007 0501 01/08/2007 1319 0.88 24 2

Route 2 -S 423027071291302 03/17/2007 1312 03/18/2007 0228 0.31 847 241

Route 2 -S 423027071291302 04/12/2007 1346 04/12/2007 1906 1.15 1,180 90

Route 2 -S 423027071291302 05/16/2007 1515 05/16/2007 2312 0.32 533 147

Route 2 -S 423027071291302 08/08/2007 0629 08/08/2007 0829 0.51 619 107
Tables 16–21 121

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Begin time 

(hrmn)

End date 

(mm/dd/yyyy)

End time 

(hrmn)

Total

precipitation

(inches)

Total storm 

volume

(cubic feet)

Runoff

coefficient

(percent)

Route 2 -S 423027071291302 08/06/2007 1514 08/06/2007 1544 0.31 196 56

Interstate 195 -T 414339070462201 04/23/2006 1904 04/23/2006 2350 0.82 1,040 123

Interstate 195 -T 414339070462201 06/24/2006 0215 06/24/2006 0730 2.55 2,130 81

Interstate 195 -T 414339070462201 09/29/2006 0121 09/29/2006 1318 0.67 250 36

Interstate 195 -T 414339070462201 12/01/2006 0907 12/01/2006 1742 0.39 106 26

Interstate 195 -T 414339070462201 02/14/2007 1208 02/14/2007 1419 0.63 769 118

Interstate 495 -P 422821071332001 09/15/2005 0951 09/15/2005 1559 0.29 569 142

Interstate 495 -P 422821071332001 09/29/2005 1439 09/29/2005 1613 0.46 1,040 164

Interstate 495 -P 422821071332001 10/22/2005 1940 10/23/2005 0720 1.28 2,990 169

Interstate 495 -P 422821071332001 10/24/2005 2200 10/25/2005 0953 2.99 6,440 156

Interstate 495 -P 422821071332001 01/11/2006 2021 01/12/2006 0039 0.5 2,530 366

Interstate 495 -P 422821071332001 03/13/2006 1309 03/14/2006 1040 0.53 2,090 285

Interstate 495 -P 422821071332001 05/09/2006 1458 05/10/2006 0800 0.86 1,980 167

Interstate 495 -P 422821071332001 06/02/2006 0554 06/03/2006 1705 2.57 8,380 236

Interstate 495 -P 422821071332001 08/20/2006 0314 08/20/2006 0940 1.36 3,660 195

Interstate 495 -P 422821071332001 08/27/2006 1429 08/28/2006 0417 0.85 1,730 147

Interstate 495 -P 422821071332001 09/19/2006 2048 09/19/2006 2357 0.64 1,080 122

Interstate 495 -P 422821071332001 11/12/2006 1206 11/12/2006 1650 1.83 1,340 53

Interstate 495 -P 422821071332001 01/08/2007 0456 01/08/2007 1450 0.88 1,470 121

Interstate 495 -P 422821071332001 03/02/2007 0335 03/02/2007 0930 1.95 8,500 316

Interstate 495 -P 422821071332001 04/12/2007 1233 04/12/2007 1857 1.06 1,060 72

Interstate 495 -P 422821071332001 08/06/2007 1502 08/06/2007 1521 0.23 200 63

Interstate 495 -P 422821071332001 08/08/2007 0612 08/08/2007 0739 0.51 614 87

Interstate 495 -P 422821071332001 09/10/2007 2252 09/10/2007 2312 0.37 364 71

Interstate 495 -S 422716071343901 09/15/2005 0958 09/15/2005 1255 0.29 207 1

Interstate 495 -S 422716071343901 09/29/2005 1441 09/29/2005 1626 0.46 460 1

Interstate 495 -S 422716071343901 10/22/2005 1856 10/23/2005 0105 1.29 2,210 1

Interstate 495 -S 422716071343901 10/24/2005 2156 10/26/2005 0518 2.99 4,830 1

Interstate 495 -S 422716071343901 01/11/2006 2024 01/12/2006 0114 0.5 920 2

Interstate 495 -S 422716071343901 01/18/2006 0259 01/18/2006 1801 1.14 1,700 1

Interstate 495 -S 422716071343901 03/13/2006 2246 03/14/2006 0548 0.53 1,390 2

Interstate 495 -S 422716071343901 05/09/2006 1506 05/10/2006 0535 0.86 986 1

Interstate 495 -S 422716071343901 06/02/2006 2058 06/04/2006 0032 2.57 2,440 1

Interstate 495 -S 422716071343901 08/20/2006 0315 08/20/2006 2052 1.36 1,390 1

Interstate 495 -S 422716071343901 09/19/2006 2048 09/19/2006 2345 0.64 1,110 1
122 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Begin time 

(hrmn)

End date 

(mm/dd/yyyy)

End time 

(hrmn)

Total

precipitation

(inches)

Total storm 

volume

(cubic feet)

Runoff

coefficient

(percent)

Interstate 95 -P 422620071153301 09/15/2005 1007 09/15/2005 1620 0.96 1,760 70

Interstate 95 -P 422620071153301 09/29/2005 1518 09/29/2005 1630 0.39 548 54

Interstate 95 -P 422620071153301 10/22/2005 2356 10/23/2005 0045 0.99 842 32

Interstate 95 -P 422620071153301 11/16/2005 2056 11/17/2005 0221 0.6 713 45

Interstate 95 -P 422620071153301 01/12/2006 0026 01/12/2006 0106 0.28 230 31

Interstate 95 -P 422620071153301 01/18/2006 1311 01/18/2006 1535 0.72 1,150 61

Interstate 95 -P 422620071153301 03/13/2006 2311 03/13/2006 2343 0.52 625 46

Interstate 95 -P 422620071153301 05/09/2006 1456 05/09/2006 2010 1.12 1,540 52

Interstate 95 -P 422620071153301 06/02/2006 0356 06/03/2006 1517 0.18 9,880 149

Interstate 95 -P 422620071153301 08/20/2006 0429 08/20/2006 0652 0.49 2,590 97

Interstate 95 -P 422620071153301 08/27/2006 1636 08/27/2006 2300 0.72 2,230 118

Interstate 95 -P 422620071153301 09/19/2006 2136 09/20/2006 0000 0.71 3,330 179

Interstate 95 -P 422620071153301 10/20/2006 1601 10/20/2006 1812 0.59 837 54

Interstate 95 -P 422620071153301 10/28/2006 0551 10/28/2006 1440 1.92 2,700 54

Interstate 95 -P 422620071153301 11/07/2006 2306 11/08/2006 2331 1.54 2,350 58

Interstate 95 -P 422620071153301 03/11/2007 0320 03/11/2007 0508 0.23 195 32

Interstate 95 -P 422620071153301 03/17/2007 0311 03/17/2007 1017 1.86 235 5

Interstate 95 -P 422620071153301 04/12/2007 1403 04/12/2007 1726 1.06 1,060 38

Interstate 95 -P 422620071153301 08/06/2007 1538 08/06/2007 1605 E0.28 35 --

Interstate 95 -P 422620071153301 08/08/2007 0722 08/08/2007 0859 E0.19 113 --

Interstate 95 -S 422420071153302 08/20/2006 0334 08/20/2006 0654 0.81 654 76

Interstate 95 -S 422420071153302 08/27/2006 1556 08/28/2006 0133 0.72 443 58

Interstate 95 -S 422420071153302 09/19/2006 2028 09/20/2006 0005 0.71 542 72

Interstate 95 -S 422420071153302 11/07/2006 2138 11/09/2006 0104 1.28 856 63

Interstate 95 -S 422420071153302 03/02/2007 0257 03/02/2007 1019 1.81 1,840 96

Interstate 95 -S 422420071153302 03/17/2007 0226 03/17/2007 0900 2.25 731 31

Interstate 95 -S 422420071153302 04/12/2007 1353 04/12/2007 1817 1.03 553 51

Interstate 95 -S 422420071153302 05/16/2007 1532 05/16/2007 1831 1.41 811 54

Interstate 95 -S 422420071153302 08/06/2007 1541 08/06/2007 1601 0.28 91 31

Interstate 95 -S 422420071153302 08/08/2007 0726 08/08/2007 0753 0.19 60 30

Interstate 93 -T 421647071024703 04/23/2006 1444 04/24/2006 0423 0.64 2,320 67

Interstate 93 -T 421647071024703 06/23/2006 1427 06/23/2006 1847 1.6 6,100 71

Interstate 93 -T 421647071024703 09/19/2006 2235 09/20/2006 0321 0.61 2,600 79

Interstate 93 -T 421647071024703 12/01/2006 1634 12/01/2006 2217 0.26 829 59

Interstate 93 -T 421647071024703 02/14/2007 1108 02/14/2007 1436 2 8,690 94
Tables 16–21 123

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Antecedent dry 

period

between

periods of flow

(days)

Storm

duration

(hours)

Sampled

duration

Turbidity

(NTRU)

pH, total,

field

(standard units)

Route 119 -P 424209071545201 09/15/2005 14.3 41.1 11.0 16 5.9

Route 119 -P 424209071545201 09/29/2005 2.6 2.0 1.6 13 5.5

Route 119 -P 424209071545201 10/22/2005 7.1 10.8 4.1 6.8 6.5

Route 119 -P 424209071545201 10/24/2005 1.6 19.5 14.3 2.2 6.2

Route 119 -P 424209071545201 01/11/2006 12.8 4.7 3.1 260 6.8

Route 119 -P 424209071545201 01/18/2006 3.5 8.6 7.1 150 7.1

Route 119 -P 424209071545201 03/13/2006 24.0 10.3 1.5 400 7

Route 119 -P 424209071545201 05/09/2006 0.3 18.3 13.2 13 6.8

Route 119 -P 424209071545201 06/01/2006 11.2 9.3 8.9 48 6.6

Route 119 -P 424209071545201 09/14/2006 8.8 5.9 5.3 12 6.3

Route 119 -P 424209071545201 09/19/2006 4.9 5.9 5.9 9.1 6

Route 119 -P 424209071545201 10/20/2006 1.8 15.9 10.4 5.5 6.5

Route 119 -P 424209071545201 11/08/2006 5.8 25.7 17.1 6.2 6.3

Route 119 -P 424209071545201 11/12/2006 3.3 6.1 2.3 2.5 6.1

Route 119 -P 424209071545201 01/08/2007 1.1 14.9 13.5 17 6.2

Route 119 -P 424209071545201 04/01/2007 5.8 7.2 7.2 35 7.2

Route 119 -P 424209071545201 04/14/2007 2.8 77.7 36.0 65 7.2

Route 119 -P 424209071545201 06/03/2007 1.6 30.9 29.7 6.7 6.8

Route 119 -P 424209071545201 07/11/2007 1.6 10.4 2.8 5.7 6.2

Route 119 -S 424155071543201 09/29/2005 2.6 0.5 0.4 2 5.7

Route 119 -S 424155071543201 10/24/2005 1.6 8.0 5.8 1.9 6.1

Route 119 -S 424155071543201 01/11/2006 12.8 3.0 2.8 240 6.5

Route 119 -S 424155071543201 01/18/2006 3.5 4.1 4.0 130 7.1

Route 119 -S 424155071543201 03/13/2006 24.0 11.4 11.4 230 6.9

Route 119 -S 424155071543201 08/20/2006 4.9 6.1 1.9 5 6.5

Route 119 -S 424155071543201 11/08/2006 3.3 10.5 9.5 2.5 6.3

Route 119 -S 424155071543201 04/27/2007 1.2 1.0 0.4 27 7.3

Route 119 -S 424155071543201 06/03/2007 1.6 22.9 22.9 8.2 6.5

Route 119 -S 424155071543201 07/11/2007 1.6 1.5 1.4 5.3 6.3

Route 119 -S 424155071543201 08/03/2007 4.0 0.4 0.4 5 6.7

Route 8 -T 424019073062601 04/22/2006 7.4 26 19.8 15 7.3

Route 8 -T 424019073062601 06/23/2006 3.1 7 11.7 16 7

Route 8 -T 424019073062601 09/23/2006 1.1 30 29.8 20 7.2

Route 8 -T 424019073062601 12/01/2006 7.9 6 6.0 56 7.6

Route 8 -T 424019073062601 03/02/2007 3.1 5 4.7 570 7.7
124 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Antecedent dry 

period

between

periods of flow

(days)

Storm

duration

(hours)

Sampled

duration

Turbidity

(NTRU)

pH, total,

field

(standard units)

Interstate 190 -T 423016071431501 08/14/2005 12.2 16 14.3 33 6

Interstate 190 -T 423016071431501 09/29/2005 2.8 1 0.7 38 6.3

Interstate 190 -T 423016071431501 10/07/2005 8.4 30 12.0 12 6

Interstate 190 -T 423016071431501 10/22/2005 7.1 11 5.6 13 6.2

Interstate 190 -T 423016071431501 10/24/2005 1.6 24 8.5 3.2 6.2

Interstate 190 -T 423016071431501 03/13/2006 16.0 7 11.1 500 6.8

Route 2 -P 423027071291301 09/15/2005 14.3 6.3 3.1 37 6.6

Route 2 -P 423027071291301 09/29/2005 2.7 1.5 1.4 31 5.9

Route 2 -P 423027071291301 10/22/2005 7 11.1 5.2 12 6.2

Route 2 -P 423027071291301 10/24/2005 1.5 30.6 7.4 3.9 6.2

Route 2 -P 423027071291301 01/11/2006 3.1 4.4 6.8 400 7

Route 2 -P 423027071291301 01/18/2006 2.5 11.6 9.6 190 6.8

Route 2 -P 423027071291301 03/13/2006 15.7 13.2 3.5 290 7.1

Route 2 -P 423027071291301 05/09/2006 5.6 21.9 21.3 1.4 7

Route 2 -P 423027071291301 06/02/2006 7 29.9 29.5 23 6.8

Route 2 -P 423027071291301 06/23/2006 8.4 16.8 3.0 84 6.6

Route 2 -P 423027071291301 08/20/2006 4.7 5.2 4.9 6.9 6.5

Route 2 -P 423027071291301 08/27/2006 1.9 6.8 13.4 4.8 6.6

Route 2 -P 423027071291301 09/19/2006 5 3 2.9 7.6 6.5

Route 2 -P 423027071291301 11/07/2006 5.5 30.6 16.8 7.2 6.6

Route 2 -P 423027071291301 01/08/2007 2.2 9.8 11.8 27 6.6

Route 2 -P 423027071291301 03/02/2007 3.4 10.7 3.0 440 7.5

Route 2 -P 423027071291301 04/12/2007 7.1 4.4 3.8 210 6.9

Route 2 -P 423027071291301 08/06/2007 7.4 0.3 0.3 27 6.7

Route 2 -P 423027071291301 08/08/2007 1.6 1.3 1.3 29 6.6

Route 2 -P 423027071291301 09/10/2007 23.9 1.1 2.0 18 6.8

Route 2 -S 423027071291302 08/20/2006 0.5 0.7 4.9 3.8 6.5

Route 2 -S 423027071291302 08/27/2006 2.3 6.7 6.9 4.9 6.4

Route 2 -S 423027071291302 09/19/2006 5.0 2.9 2.9 12 6.2

Route 2 -S 423027071291302 12/01/2006 7.6 5.0 5.2 24 6.6

Route 2 -S 423027071291302 01/08/2007 2.2 0.8 8.3 20 6.8

Route 2 -S 423027071291302 03/17/2007 0.1 13.2 13.3 80 7

Route 2 -S 423027071291302 04/12/2007 6.9 7.0 5.3 120 6.8

Route 2 -S 423027071291302 05/16/2007 0.6 8.0 8.0 27 6.2

Route 2 -S 423027071291302 08/08/2007 7.3 0.6 2.0 24 6.3
Tables 16–21 125

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Antecedent dry 

period

between

periods of flow

(days)

Storm

duration

(hours)

Sampled

duration

Turbidity

(NTRU)

pH, total,

field

(standard units)

Route 2 -S 423027071291302 08/06/2007 1.6 1.9 0.5 27 6.4

Interstate 195 -T 414339070462201 04/23/2006 8.8 6 4.8 24 6.8

Interstate 195 -T 414339070462201 06/24/2006 3.8 33 5.3 8.3 6

Interstate 195 -T 414339070462201 09/29/2006 8.9 3 12.0 9.7 5.9

Interstate 195 -T 414339070462201 12/01/2006 7.1 9 8.6 17 6.5

Interstate 195 -T 414339070462201 02/14/2007 11.4 6 2.2 45 6.2

Interstate 495 -P 422821071332001 09/15/2005 14.3 6.0 6.1 49 6.1

Interstate 495 -P 422821071332001 09/29/2005 2.7 2.0 1.6 33 5.7

Interstate 495 -P 422821071332001 10/22/2005 7.1 12.0 11.7 12 6

Interstate 495 -P 422821071332001 10/24/2005 1.6 32.0 11.9 9 5.7

Interstate 495 -P 422821071332001 01/11/2006 3.3 8.0 4.3 670 7.7

Interstate 495 -P 422821071332001 03/13/2006 17.8 23.0 21.5 400 6.9

Interstate 495 -P 422821071332001 05/09/2006 6.9 27.0 17.0 32 6.7

Interstate 495 -P 422821071332001 06/02/2006 6.4 38.0 35.2 23 6.6

Interstate 495 -P 422821071332001 08/20/2006 4.7 7.0 6.4 9.3 6.6

Interstate 495 -P 422821071332001 08/27/2006 1.9 11.0 13.8 12 6.6

Interstate 495 -P 422821071332001 09/19/2006 5 3.0 3.1 17 6

Interstate 495 -P 422821071332001 11/12/2006 3.4 5.0 4.7 15 6.2

Interstate 495 -P 422821071332001 01/08/2007 1.8 10.0 9.9 28 6.7

Interstate 495 -P 422821071332001 03/02/2007 3.7 12.0 5.9 470 8

Interstate 495 -P 422821071332001 04/12/2007 6.9 8.0 6.4 200 7

Interstate 495 -P 422821071332001 08/06/2007 7.1 1.0 0.3 37 6.5

Interstate 495 -P 422821071332001 08/08/2007 1.6 2.0 1.5 39 6.4

Interstate 495 -P 422821071332001 09/10/2007 1.7 1.0 0.3 20 7.1

Interstate 495 -S 422716071343901 09/15/2005 14.3 6.0 3.0 40 6.1

Interstate 495 -S 422716071343901 09/29/2005 2.7 1.7 1.7 20 5.8

Interstate 495 -S 422716071343901 10/22/2005 7.1 13.3 6.1 14 6.2

Interstate 495 -S 422716071343901 10/24/2005 1.6 31.5 31.4 9.4 6.2

Interstate 495 -S 422716071343901 01/11/2006 3.3 5.2 4.8 540 7.3

Interstate 495 -S 422716071343901 01/18/2006 2.6 15.7 15.0 230 7

Interstate 495 -S 422716071343901 03/13/2006 15.7 22.0 7.0 280 7

Interstate 495 -S 422716071343901 05/09/2006 6.9 8.6 14.5 31 6.6

Interstate 495 -S 422716071343901 06/02/2006 7.1 22.5 27.6 15 7

Interstate 495 -S 422716071343901 08/20/2006 4.7 7.1 17.6 13 6.4

Interstate 495 -S 422716071343901 09/19/2006 5.0 3.4 3.0 16 6.2
126 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Antecedent dry 

period

between

periods of flow

(days)

Storm

duration

(hours)

Sampled

duration

Turbidity

(NTRU)

pH, total,

field

(standard units)

Interstate 95 -P 422620071153301 09/15/2005 14.3 9 6.2 34 6.8

Interstate 95 -P 422620071153301 09/29/2005 2.6 2 1.2 16 6.2

Interstate 95 -P 422620071153301 10/22/2005 7.2 7 0.8 7.1 6.6

Interstate 95 -P 422620071153301 11/16/2005 4.9 14 5.4 16 6.4

Interstate 95 -P 422620071153301 01/12/2006 16.3 1 0.7 730 6.8

Interstate 95 -P 422620071153301 01/18/2006 3.5 3 2.4 290 6.9

Interstate 95 -P 422620071153301 03/13/2006 36.7 9 0.5 670 6.6

Interstate 95 -P 422620071153301 05/09/2006 6.6 5 5.2 55 6.7

Interstate 95 -P 422620071153301 06/02/2006 14 29 35.3 22 6.9

Interstate 95 -P 422620071153301 08/20/2006 4.6 7 2.4 6.4 6.6

Interstate 95 -P 422620071153301 08/27/2006 2 10 6.4 9.6 6.9

Interstate 95 -P 422620071153301 09/19/2006 5 5 2.4 11 6.4

Interstate 95 -P 422620071153301 10/20/2006 8.5 3 2.2 28 6.9

Interstate 95 -P 422620071153301 10/28/2006 7.4 11 8.8 15 6.6

Interstate 95 -P 422620071153301 11/07/2006 10.3 27 24.4 26 6.7

Interstate 95 -P 422620071153301 03/11/2007 8.5 2 1.8 180 7

Interstate 95 -P 422620071153301 03/17/2007 5.9 4 7.1 310 7.1

Interstate 95 -P 422620071153301 04/12/2007 7.4 4 3.4 150 6.8

Interstate 95 -P 422620071153301 08/06/2007 7 <1 0.4 24 6.6

Interstate 95 -P 422620071153301 08/08/2007 1.6 1 1.6 33 6.6

Interstate 95 -S 422420071153302 08/20/2006 4.7 3.0 3.3 7.2 6.4

Interstate 95 -S 422420071153302 08/27/2006 2.0 10.0 9.6 10 6.6

Interstate 95 -S 422420071153302 09/19/2006 5.0 5.0 3.6 15 6.2

Interstate 95 -S 422420071153302 11/07/2006 5.5 28.0 27.4 15 6.6

Interstate 95 -S 422420071153302 03/02/2007 3.6 11.0 7.4 420 7

Interstate 95 -S 422420071153302 03/17/2007 0.6 6.0 6.6 260 7.1

Interstate 95 -S 422420071153302 04/12/2007 7.1 4.0 4.4 100 6.9

Interstate 95 -S 422420071153302 05/16/2007 0.7 7.0 3.0 46 6.1

Interstate 95 -S 422420071153302 08/06/2007 7.0 <1 0.3 34 6.4

Interstate 95 -S 422420071153302 08/08/2007 1.6 1.0 0.5 47 6.6

Interstate 93 -T 421647071024703 04/23/2006 15.3 14 13.6 91 7.1

Interstate 93 -T 421647071024703 06/23/2006 2.7 5 4.3 78 6.6

Interstate 93 -T 421647071024703 09/19/2006 5.1 5 4.8 28 6.8

Interstate 93 -T 421647071024703 12/01/2006 3.1 6 5.7 96 6.9

Interstate 93 -T 421647071024703 02/14/2007 11 8 3 540 7
Tables 16–21 127

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

pH, total,

laboratory

(standard

units)

Specific

conductance, 

laboratory

(μS/cm)

Specific

conductance, 

field

(μS/cm)

Hardness

(mg/L as

calcium

carbonate)

Calcium,

dissolved

(mg/L)

Route 119 -P 424209071545201 09/15/2005 6.6 346 354 29 8.31

Route 119 -P 424209071545201 09/29/2005 7 29 30 2 0.74

Route 119 -P 424209071545201 10/22/2005 -- -- 37 -- --

Route 119 -P 424209071545201 10/24/2005 8.5 8 7 1 0.36

Route 119 -P 424209071545201 01/11/2006 7.5 4,940 5,430 130 15.9

Route 119 -P 424209071545201 01/18/2006 7.5 3,540 3,580 120 36.2

Route 119 -P 424209071545201 03/13/2006 7.5 494 490 31 4.95

Route 119 -P 424209071545201 05/09/2006 6.5 308 306 17 4.29

Route 119 -P 424209071545201 06/01/2006 7.1 254 254 15 3.73

Route 119 -P 424209071545201 09/14/2006 7.2 74 73 5 1.49

Route 119 -P 424209071545201 09/19/2006 6.6 151 150 12 3.33

Route 119 -P 424209071545201 10/20/2006 7.8 53 50 -- --

Route 119 -P 424209071545201 11/08/2006 7.4 32 28 3 0.85

Route 119 -P 424209071545201 11/12/2006 -- -- 24 -- --

Route 119 -P 424209071545201 01/08/2007 7.1 102 103 3 0.64

Route 119 -P 424209071545201 04/01/2007 7.6 1,820 1,850 15 3.34

Route 119 -P 424209071545201 04/14/2007 7.9 9,200 9,160 260 15.5

Route 119 -P 424209071545201 06/03/2007 7.6 69 65 4 1.04

Route 119 -P 424209071545201 07/11/2007 7.4 50 47 4 0.96

Route 119 -S 424155071543201 09/29/2005 7 20 21 2 0.55

Route 119 -S 424155071543201 10/24/2005 6.1 10 8 1 0.3

Route 119 -S 424155071543201 01/11/2006 7.5 2,960 3,130 83 14.2

Route 119 -S 424155071543201 01/18/2006 7.5 2,810 2,850 91 26.8

Route 119 -S 424155071543201 03/13/2006 7 1,090 1,100 42 8.63

Route 119 -S 424155071543201 08/20/2006 7.9 44 43 5 1.56

Route 119 -S 424155071543201 11/08/2006 7.9 16 11 2 0.55

Route 119 -S 424155071543201 04/27/2007 7.1 2,750 2,710 95 22.9

Route 119 -S 424155071543201 06/03/2007 7.8 90 89 -- --

Route 119 -S 424155071543201 07/11/2007 8.2 28 25 2 0.52

Route 119 -S 424155071543201 08/03/2007 6.7 136 134 13 3.72

Route 8 -T 424019073062601 04/22/2006 7.3 48 48 11 4.24

Route 8 -T 424019073062601 06/23/2006 7 65 65 22 8.27

Route 8 -T 424019073062601 09/23/2006 7.2 71 68 27 10.2

Route 8 -T 424019073062601 12/01/2006 8.2 48 48 16 5.93

Route 8 -T 424019073062601 03/02/2007 7.8 E14,400 14,400 77 29.7
128 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

pH, total,

laboratory

(standard

units)

Specific

conductance, 

laboratory

(μS/cm)

Specific

conductance, 

field

(μS/cm)

Hardness

(mg/L as

calcium

carbonate)

Calcium,

dissolved

(mg/L)

Interstate 190 -T 423016071431501 08/14/2005 6.8 89 97 17 6.03

Interstate 190 -T 423016071431501 09/29/2005 6.8 71 75 12 4.16

Interstate 190 -T 423016071431501 10/07/2005 7.5 35 35 7 2.54

Interstate 190 -T 423016071431501 10/22/2005 7.2 70 72 14 4.96

Interstate 190 -T 423016071431501 10/24/2005 7.9 15 15 4 1.25

Interstate 190 -T 423016071431501 03/13/2006 7.2 E11,300 11,300 600 125

Route 2 -P 423027071291301 09/15/2005 7.1 268 273 21 6.62

Route 2 -P 423027071291301 09/29/2005 6.9 79 85 7 2.34

Route 2 -P 423027071291301 10/22/2005 7.2 90 93 9 2.79

Route 2 -P 423027071291301 10/24/2005 8.2 35 34 4 1.3

Route 2 -P 423027071291301 01/11/2006 7.5 2,870 3,190 97 21.9

Route 2 -P 423027071291301 01/18/2006 7.5 1,870 1,920 57 12.5

Route 2 -P 423027071291301 03/13/2006 7.2 1,820 1,840 59 13.8

Route 2 -P 423027071291301 05/09/2006 7.2 261 237 15 4.28

Route 2 -P 423027071291301 06/02/2006 7.9 49 45 4 1.38

Route 2 -P 423027071291301 06/23/2006 -- -- 226 -- --

Route 2 -P 423027071291301 08/20/2006 7.4 61 60 5 1.74

Route 2 -P 423027071291301 08/27/2006 7.2 69 69 7 2.28

Route 2 -P 423027071291301 09/19/2006 7 76 72 7 2.29

Route 2 -P 423027071291301 11/07/2006 7.1 92 88 10 3.06

Route 2 -P 423027071291301 01/08/2007 6.5 151 152 8 1.98

Route 2 -P 423027071291301 03/02/2007 7.5 E29,900 29,900 840 108

Route 2 -P 423027071291301 04/12/2007 7.2 3,390 3,330 100 8.72

Route 2 -P 423027071291301 08/06/2007 6.8 229 226 -- --

Route 2 -P 423027071291301 08/08/2007 6.8 108 104 9 2.92

Route 2 -P 423027071291301 09/10/2007 7.9 126 123 10 3.24

Route 2 -S 423027071291302 08/20/2006 -- -- 73 7 2.1

Route 2 -S 423027071291302 08/27/2006 6.3 58 57 6 1.9

Route 2 -S 423027071291302 09/19/2006 7 63 59 7 2.1

Route 2 -S 423027071291302 12/01/2006 7.7 45 46 5 1.66

Route 2 -S 423027071291302 01/08/2007 8 138 138 7 1.57

Route 2 -S 423027071291302 03/17/2007 7.6 E60,500 62,500 650 88

Route 2 -S 423027071291302 04/12/2007 7.3 2,500 2,460 76 7.09

Route 2 -S 423027071291302 05/16/2007 6.6 64 61 5 1.43

Route 2 -S 423027071291302 08/08/2007 6.3 94 89 9 2.93
Tables 16–21 129

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

pH, total,

laboratory

(standard

units)

Specific

conductance, 

laboratory

(μS/cm)

Specific

conductance, 

field

(μS/cm)

Hardness

(mg/L as

calcium

carbonate)

Calcium,

dissolved

(mg/L)

Route 2 -S 423027071291302 08/06/2007 6.5 199 193 17 5.06

Interstate 195 -T 414339070462201 04/23/2006 7.1 118 116 5 1.31

Interstate 195 -T 414339070462201 06/24/2006 6.3 36 35 4 1.13

Interstate 195 -T 414339070462201 09/29/2006 6.1 55 53 5 1.37

Interstate 195 -T 414339070462201 12/01/2006 7.4 85 93 8 2.48

Interstate 195 -T 414339070462201 02/14/2007 7.9 3,790 3,720 9 2.92

Interstate 495 -P 422821071332001 09/15/2005 7 228 247 17 5.52

Interstate 495 -P 422821071332001 09/29/2005 6.9 66 65 5 1.58

Interstate 495 -P 422821071332001 10/22/2005 7.5 28 28 3 1.06

Interstate 495 -P 422821071332001 10/24/2005 8.1 27 27 3 1.01

Interstate 495 -P 422821071332001 01/11/2006 7.6 1,890 1,980 43 13.6

Interstate 495 -P 422821071332001 03/13/2006 7 1,670 1,680 100 25.6

Interstate 495 -P 422821071332001 05/09/2006 6.9 224 220 14 3.99

Interstate 495 -P 422821071332001 06/02/2006 6.9 145 144 9 2.77

Interstate 495 -P 422821071332001 08/20/2006 7.3 60 59 6 1.9

Interstate 495 -P 422821071332001 08/27/2006 7.3 56 54 5 1.75

Interstate 495 -P 422821071332001 09/19/2006 6.5 65 62 7 2.18

Interstate 495 -P 422821071332001 11/12/2006 7.3 27 23 3 1.01

Interstate 495 -P 422821071332001 01/08/2007 7.9 189 190 12 2.4

Interstate 495 -P 422821071332001 03/02/2007 7.7 15,300 15,400 430 38.1

Interstate 495 -P 422821071332001 04/12/2007 7.2 9,820 9,600 110 16.4

Interstate 495 -P 422821071332001 08/06/2007 6.7 178 176

Interstate 495 -P 422821071332001 08/08/2007 6.4 109 106 10 3.32

Interstate 495 -P 422821071332001 09/10/2007 6.7 125 119 10 3.04

Interstate 495 -S 422716071343901 09/15/2005 7 237 250 21 6.9

Interstate 495 -S 422716071343901 09/29/2005 7 73 79 7 2.21

Interstate 495 -S 422716071343901 10/22/2005 8 107 110 10 3.35

Interstate 495 -S 422716071343901 10/24/2005 8 26 26 3 1.14

Interstate 495 -S 422716071343901 01/11/2006 7.4 7,120 7,600 120 35.3

Interstate 495 -S 422716071343901 01/18/2006 7.5 4,820 4,930 200 75.1

Interstate 495 -S 422716071343901 03/13/2006 7.6 2,640 2,630 140 37.8

Interstate 495 -S 422716071343901 05/09/2006 7.4 242 237 15 4.38

Interstate 495 -S 422716071343901 06/02/2006 7.8 53 48 4 1.44

Interstate 495 -S 422716071343901 08/20/2006 7.7 67 67 6 1.92

Interstate 495 -S 422716071343901 09/19/2006 6.7 71 69 7 2.4
130 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

pH, total,

laboratory

(standard

units)

Specific

conductance, 

laboratory

(μS/cm)

Specific

conductance, 

field

(μS/cm)

Hardness

(mg/L as

calcium

carbonate)

Calcium,

dissolved

(mg/L)

Interstate 95 -P 422620071153301 09/15/2005 7.1 117 128 18 6.09

Interstate 95 -P 422620071153301 09/29/2005 6.7 130 141 20 6.89

Interstate 95 -P 422620071153301 10/22/2005 7.4 54 55 9 3.1

Interstate 95 -P 422620071153301 11/16/2005 7.8 140 146 13 4.46

Interstate 95 -P 422620071153301 01/12/2006 7.1 E12,900 13,700 560 191

Interstate 95 -P 422620071153301 01/18/2006 7.1 4,000 4,080 200 77.1

Interstate 95 -P 422620071153301 03/13/2006 6.5 E18,500 18,700 960 270

Interstate 95 -P 422620071153301 05/09/2006 6.8 442 437 21 6.44

Interstate 95 -P 422620071153301 06/02/2006 7.1 124 123 9 2.95

Interstate 95 -P 422620071153301 08/20/2006 7.3 98 98 13 4.21

Interstate 95 -P 422620071153301 08/27/2006 6.7 95 93 12 3.89

Interstate 95 -P 422620071153301 09/19/2006 6.9 83 80 12 3.8

Interstate 95 -P 422620071153301 10/20/2006 7.5 82 83 -- --

Interstate 95 -P 422620071153301 10/28/2006 7.4 50 47 -- --

Interstate 95 -P 422620071153301 11/07/2006 7.2 60 55 10 3.41

Interstate 95 -P 422620071153301 03/11/2007 6.8 E13,300 13,400 740 215

Interstate 95 -P 422620071153301 03/17/2007 7.4 E13,800 14,300 720 194

Interstate 95 -P 422620071153301 04/12/2007 6.9 3,700 3,640 160 47.4

Interstate 95 -P 422620071153301 08/06/2007 6.6 214 211 22 7.38

Interstate 95 -P 422620071153301 08/08/2007 6.5 179 174 10 6.16

Interstate 95 -S 422420071153302 08/20/2006 7.2 53 51 14 5.23

Interstate 95 -S 422420071153302 08/27/2006 7.1 60 59 11 4.1

Interstate 95 -S 422420071153302 09/19/2006 7 58 55 12 4.11

Interstate 95 -S 422420071153302 11/07/2006 7.2 49 45 9 3.32

Interstate 95 -S 422420071153302 03/02/2007 7.1 E13,000 12,900 1,300 502

Interstate 95 -S 422420071153302 03/17/2007 7.7 E15,100 15,600 590 167

Interstate 95 -S 422420071153302 04/12/2007 7 971 954 51 18.8

Interstate 95 -S 422420071153302 05/16/2007 6.1 112 107 11 3.75

Interstate 95 -S 422420071153302 08/06/2007 6.7 154 145 24 8.46

Interstate 95 -S 422420071153302 08/08/2007 6.2 163 161 21 7.55

Interstate 93 -T 421647071024703 04/23/2006 7 1,260 1,240 37 9.74

Interstate 93 -T 421647071024703 06/23/2006 6.7 136 137 12 4.16

Interstate 93 -T 421647071024703 09/19/2006 7.1 112 108 9 3.15

Interstate 93 -T 421647071024703 12/01/2006 7.4 172 183 21 7.17

Interstate 93 -T 421647071024703 02/14/2007 8 E12,900 13,200 400 48
Tables 16–21 131

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Magnesium, 

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Sodium,

dissolved

(mg/L)

Alkalinity,

dissolved,

laboratory

(mg/L as

calcium

carbonate)

Chloride,

dissolved

(mg/L)

Route 119 -P 424209071545201 09/15/2005 2 1.36 54.3 8 89.5

Route 119 -P 424209071545201 09/29/2005 0.159 0.22 4.46 <5 6.37

Route 119 -P 424209071545201 10/22/2005 -- -- -- -- --

Route 119 -P 424209071545201 10/24/2005 0.062 <0.16 0.84 <5 0.99

Route 119 -P 424209071545201 01/11/2006 22.6 7.32 970 12 1,620

Route 119 -P 424209071545201 01/18/2006 8.26 4.37 619 9 1,100

Route 119 -P 424209071545201 03/13/2006 4.61 1.3 73.8 14 121

Route 119 -P 424209071545201 05/09/2006 1.57 0.98 49.5 13 78.6

Route 119 -P 424209071545201 06/01/2006 1.5 0.76 38.8 9 63.5

Route 119 -P 424209071545201 09/14/2006 0.368 0.33 10.9 6 15.1

Route 119 -P 424209071545201 09/19/2006 0.945 0.7 21.2 6 32.8

Route 119 -P 424209071545201 10/20/2006 -- -- -- 6 8.82

Route 119 -P 424209071545201 11/08/2006 0.153 0.14 4.08 5 5.62

Route 119 -P 424209071545201 11/12/2006 -- -- -- -- --

Route 119 -P 424209071545201 01/08/2007 0.317 0.19 17.9 6 26

Route 119 -P 424209071545201 04/01/2007 1.51 0.92 338 15 562

Route 119 -P 424209071545201 04/14/2007 53.8 14 1,750 14 2,880

Route 119 -P 424209071545201 06/03/2007 0.329 0.26 9.79 7 12.8

Route 119 -P 424209071545201 07/11/2007 0.272 0.19 7.58 <5 9.92

Route 119 -S 424155071543201 09/29/2005 0.1 0.17 2.99 <5 4.08

Route 119 -S 424155071543201 10/24/2005 0.075 <0.16 1.18 <5 1.25

Route 119 -S 424155071543201 01/11/2006 11.6 3.7 548 17 921

Route 119 -S 424155071543201 01/18/2006 5.85 3.09 471 10 864

Route 119 -S 424155071543201 03/13/2006 4.86 1.64 185 18 302

Route 119 -S 424155071543201 08/20/2006 0.237 0.27 5.93 8 7.62

Route 119 -S 424155071543201 11/08/2006 0.094 0.08 1.34 <5 1.69

Route 119 -S 424155071543201 04/27/2007 9.29 3.13 466 37 808

Route 119 -S 424155071543201 06/03/2007 -- -- -- -- --

Route 119 -S 424155071543201 07/11/2007 0.137 0.17 3.9 <5 4.92

Route 119 -S 424155071543201 08/03/2007 1.02 1.04 18.1 8 28.2

Route 8 -T 424019073062601 04/22/2006 0.134 E0.14 4.85 15 5.35

Route 8 -T 424019073062601 06/23/2006 0.282 0.31 3.01 22 2.4

Route 8 -T 424019073062601 09/23/2006 0.508 0.61 2.71 20 2.64

Route 8 -T 424019073062601 12/01/2006 0.171 0.23 1.82 16 2.02

Route 8 -T 424019073062601 03/02/2007 0.723 3.07 2,890 38 4,930
132 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Magnesium, 

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Sodium,

dissolved

(mg/L)

Alkalinity,

dissolved,

laboratory

(mg/L as

calcium

carbonate)

Chloride,

dissolved

(mg/L)

Interstate 190 -T 423016071431501 08/14/2005 0.474 0.58 9.49 7 12.5

Interstate 190 -T 423016071431501 09/29/2005 0.384 0.78 8.83 9 12

Interstate 190 -T 423016071431501 10/07/2005 0.218 0.37 3.31 8 4.03

Interstate 190 -T 423016071431501 10/22/2005 0.507 0.89 6.84 11 9.35

Interstate 190 -T 423016071431501 10/24/2005 0.115 0.2 1.08 6 1.54

Interstate 190 -T 423016071431501 03/13/2006 70.6 17.9 2050 19 3710

Route 2 -P 423027071291301 09/15/2005 1 1.8 42 12 62.6

Route 2 -P 423027071291301 09/29/2005 0.346 1.54 11.9 8 16.9

Route 2 -P 423027071291301 10/22/2005 0.435 1.38 12.2 9 18.6

Route 2 -P 423027071291301 10/24/2005 0.182 0.46 4.44 6 6.05

Route 2 -P 423027071291301 01/11/2006 10.4 4.39 561 18 915

Route 2 -P 423027071291301 01/18/2006 6.32 2.58 328 16 558

Route 2 -P 423027071291301 03/13/2006 5.84 2.43 321 13 538

Route 2 -P 423027071291301 05/09/2006 1 0.75 38.1 15 56.7

Route 2 -P 423027071291301 06/02/2006 0.241 0.32 6.04 7 7.58

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 0.279 0.53 9.88 7 13.2

Route 2 -P 423027071291301 08/27/2006 0.35 0.36 8.74 8 11.8

Route 2 -P 423027071291301 09/19/2006 0.385 0.84 9.4 6 13.2

Route 2 -P 423027071291301 11/07/2006 0.464 0.65 11.2 11 15.2

Route 2 -P 423027071291301 01/08/2007 0.793 0.39 23.5 9 37.2

Route 2 -P 423027071291301 03/02/2007 138 37 6,240 24 10,700

Route 2 -P 423027071291301 04/12/2007 19.2 5.59 588 14 1,010

Route 2 -P 423027071291301 08/06/2007 -- -- -- -- --

Route 2 -P 423027071291301 08/08/2007 0.528 0.86 13.9 8 17.6

Route 2 -P 423027071291301 09/10/2007 0.448 2.36 17.4 12 24.6

Route 2 -S 423027071291302 08/20/2006 0.331 0.99 10 6 14.1

Route 2 -S 423027071291302 08/27/2006 0.303 0.66 6.67 6 9.54

Route 2 -S 423027071291302 09/19/2006 0.346 1.27 7.01 6 9.55

Route 2 -S 423027071291302 12/01/2006 0.252 0.42 5.68 6 7.69

Route 2 -S 423027071291302 01/08/2007 0.709 0.41 21.8 7 33.8

Route 2 -S 423027071291302 03/17/2007 103 36.7 13,900 27 22,600

Route 2 -S 423027071291302 04/12/2007 14.2 4.74 425 12 727

Route 2 -S 423027071291302 05/16/2007 0.332 0.39 8.82 5 11.1

Route 2 -S 423027071291302 08/08/2007 0.498 1.02 11.1 7 15.5
Tables 16–21 133

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Magnesium, 

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Sodium,

dissolved

(mg/L)

Alkalinity,

dissolved,

laboratory

(mg/L as

calcium

carbonate)

Chloride,

dissolved

(mg/L)

Route 2 -S 423027071291302 08/06/2007 0.94 1.63 27.8 9 40.4

Interstate 195 -T 414339070462201 04/23/2006 0.3 0.29 19.8 6 28.2

Interstate 195 -T 414339070462201 06/24/2006 0.169 E0.15 3.86 <5 5.5

Interstate 195 -T 414339070462201 09/29/2006 0.272 0.29 6.84 <5 10.4

Interstate 195 -T 414339070462201 12/01/2006 0.533 0.5 12.5 8 16

Interstate 195 -T 414339070462201 02/14/2007 0.465 0.66 718 7 1,210

Interstate 495 -P 422821071332001 09/15/2005 0.819 1.62 36.4 9 52.6

Interstate 495 -P 422821071332001 09/29/2005 0.213 0.66 9.25 6 12.6

Interstate 495 -P 422821071332001 10/22/2005 0.12 0.19 3.52 5 5.24

Interstate 495 -P 422821071332001 10/24/2005 0.118 0.17 3.41 5 4.84

Interstate 495 -P 422821071332001 01/11/2006 2.09 1.77 354 15 577

Interstate 495 -P 422821071332001 03/13/2006 9.44 3.34 265 15 457

Interstate 495 -P 422821071332001 05/09/2006 0.881 0.83 35.3 11 52.5

Interstate 495 -P 422821071332001 06/02/2006 0.564 0.56 21.8 8 32.5

Interstate 495 -P 422821071332001 08/20/2006 0.24 0.35 8.02 6 11.1

Interstate 495 -P 422821071332001 08/27/2006 0.225 0.27 6.78 7 9.51

Interstate 495 -P 422821071332001 09/19/2006 0.329 0.93 7.58 5 10.3

Interstate 495 -P 422821071332001 11/12/2006 0.107 0.15 2.3 <5 2.95

Interstate 495 -P 422821071332001 01/08/2007 1.34 0.64 29.4 9 47.3

Interstate 495 -P 422821071332001 03/02/2007 81.1 21.1 2,990 20 5,190

Interstate 495 -P 422821071332001 04/12/2007 16.6 5.17 1,940 14 3,110

Interstate 495 -P 422821071332001 08/06/2007 -- -- -- -- --

Interstate 495 -P 422821071332001 08/08/2007 0.465 0.61 14 7 18.6

Interstate 495 -P 422821071332001 09/10/2007 0.534 0.8 17.4 6 26.5

Interstate 495 -S 422716071343901 09/15/2005 0.845 1.28 37.1 10 53.3

Interstate 495 -S 422716071343901 09/29/2005 0.259 0.47 11.7 6 16.1

Interstate 495 -S 422716071343901 10/22/2005 0.375 0.46 15.6 8 23.2

Interstate 495 -S 422716071343901 10/24/2005 0.113 0.17 2.98 6 4.25

Interstate 495 -S 422716071343901 01/11/2006 7.29 5.33 1,430 17 2,380

Interstate 495 -S 422716071343901 01/18/2006 3.12 3.58 850 14 1,540

Interstate 495 -S 422716071343901 03/13/2006 12.1 3.53 441 14 761

Interstate 495 -S 422716071343901 05/09/2006 0.873 0.74 37 9 53.8

Interstate 495 -S 422716071343901 06/02/2006 0.215 0.22 6.34 6 8.89

Interstate 495 -S 422716071343901 08/20/2006 0.272 0.27 9.34 5 13.5

Interstate 495 -S 422716071343901 09/19/2006 0.308 0.74 8.71 6 11.7
134 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Magnesium, 

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Sodium,

dissolved

(mg/L)

Alkalinity,

dissolved,

laboratory

(mg/L as

calcium

carbonate)

Chloride,

dissolved

(mg/L)

Interstate 95 -P 422620071153301 09/15/2005 0.73 1.5 14.8 14 17.7

Interstate 95 -P 422620071153301 09/29/2005 0.763 1.65 16.1 15 22.8

Interstate 95 -P 422620071153301 10/22/2005 0.4 0.67 5.2 -- --

Interstate 95 -P 422620071153301 11/16/2005 0.536 1.06 21.1 -- --

Interstate 95 -P 422620071153301 01/12/2006 20.9 14 2,600 19 4,500

Interstate 95 -P 422620071153301 01/18/2006 2.98 3.83 686 12 1,260

Interstate 95 -P 422620071153301 03/13/2006 68.1 23.4 3,600 23 6,200

Interstate 95 -P 422620071153301 05/09/2006 1.26 1.61 73.5 15 114

Interstate 95 -P 422620071153301 06/02/2006 0.425 0.81 18.5 13 23.5

Interstate 95 -P 422620071153301 08/20/2006 0.609 0.98 12.4 9 16.6

Interstate 95 -P 422620071153301 08/27/2006 0.545 0.96 11.1 14 13.2

Interstate 95 -P 422620071153301 09/19/2006 0.55 0.93 8.74 8 10.7

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- 14 9.15

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- 9 5.42

Interstate 95 -P 422620071153301 11/07/2006 0.398 0.79 5.12 13 5.21

Interstate 95 -P 422620071153301 03/11/2007 50 16.1 2,490 19 4,400

Interstate 95 -P 422620071153301 03/17/2007 57.6 17 2,630 19 4,570

Interstate 95 -P 422620071153301 04/12/2007 9.2 4.49 622 14 1,130

Interstate 95 -P 422620071153301 08/06/2007 0.792 2 31.3 16 39.7

Interstate 95 -P 422620071153301 08/08/2007 0.628 1.68 24.3 13 30

Interstate 95 -S 422420071153302 08/20/2006 0.228 0.76 2.9 8 6.42

Interstate 95 -S 422420071153302 08/27/2006 0.243 0.7 4.32 9 7.97

Interstate 95 -S 422420071153302 09/19/2006 0.301 0.63 3.79 6 5.57

Interstate 95 -S 422420071153302 11/07/2006 0.275 0.7 3.37 10 4.26

Interstate 95 -S 422420071153302 03/02/2007 14.9 15.8 1,980 18 4,430

Interstate 95 -S 422420071153302 03/17/2007 41.3 13.2 3,020 16 5,070

Interstate 95 -S 422420071153302 04/12/2007 1.04 1.01 159 11 276

Interstate 95 -S 422420071153302 05/16/2007 0.369 0.77 14.5 7 22

Interstate 95 -S 422420071153302 08/06/2007 0.647 1.63 16.6 13 22.6

Interstate 95 -S 422420071153302 08/08/2007 0.641 1.54 18.7 11 25.5

Interstate 93 -T 421647071024703 04/23/2006 3.15 2.64 219 21 342

Interstate 93 -T 421647071024703 06/23/2006 0.417 0.84 19.9 12 26.7

Interstate 93 -T 421647071024703 09/19/2006 0.315 0.95 15.1 14 17.7

Interstate 93 -T 421647071024703 12/01/2006 0.748 1.38 24.7 20 31.2

Interstate 93 -T 421647071024703 02/14/2007 68 21 2,500 21 4,380
Tables 16–21 135

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Sulfate,

dissolved

(mg/L)

Total nitrogen 

(nitrate + nitrite 

+ ammonia + 

organic-N),

total

(mg/L)

Phosphorus, 

total

(mg/L)

Cadmium,

total

(μg/L)

Chromium,

total,

recoverable

(μg/L)

Route 119 -P 424209071545201 09/15/2005 8.07 2.52 0.1 0.11 3.3

Route 119 -P 424209071545201 09/29/2005 1 0.4 0.04 E0.02 3.3

Route 119 -P 424209071545201 10/22/2005 -- 0.33 <0.02 E0.02 1.2

Route 119 -P 424209071545201 10/24/2005 0.34 0.09 <0.02 <0.04 1

Route 119 -P 424209071545201 01/11/2006 82.1 0.85 0.2 0.21 17

Route 119 -P 424209071545201 01/18/2006 32.7 0.61 0.19 0.15 14

Route 119 -P 424209071545201 03/13/2006 22.5 2.07 0.51 0.24 34

Route 119 -P 424209071545201 05/09/2006 6.66 0.86 0.05 E0.04 3.5

Route 119 -P 424209071545201 06/01/2006 6.09 1.49 0.24 0.08 7.9

Route 119 -P 424209071545201 09/14/2006 1.49 0.56 0.03 <0.04 4.1

Route 119 -P 424209071545201 09/19/2006 5.91 1.5 0.06 E0.03 2.9

Route 119 -P 424209071545201 10/20/2006 2.39 -- -- -- --

Route 119 -P 424209071545201 11/08/2006 0.63 0.24 E0.02 E0.009 2.1

Route 119 -P 424209071545201 11/12/2006 -- -- -- -- --

Route 119 -P 424209071545201 01/08/2007 2.17 0.21 0.03 E0.01 2.7

Route 119 -P 424209071545201 04/01/2007 11.9 0.59 0.05 0.03 3.7

Route 119 -P 424209071545201 04/14/2007 187 0.64 0.08 0.08 7.5

Route 119 -P 424209071545201 06/03/2007 2.2 0.43 E0.02 E0.01 2.4

Route 119 -P 424209071545201 07/11/2007 1.22 0.41 0.04 0.03 2.1

Route 119 -S 424155071543201 09/29/2005 0.57 0.43 0.06 E0.03 2.4

Route 119 -S 424155071543201 10/24/2005 0.47 0.1 <0.02 <0.04 0.4

Route 119 -S 424155071543201 01/11/2006 46.7 0.85 0.19 0.2 15

Route 119 -S 424155071543201 01/18/2006 27.2 0.59 0.15 0.17 9.9

Route 119 -S 424155071543201 03/13/2006 21.1 1.55 0.33 0.19 23

Route 119 -S 424155071543201 08/20/2006 0.97 0.33 0.04 <0.04 0.7

Route 119 -S 424155071543201 11/08/2006 0.25 0.1 0.03 E0.01 0.9

Route 119 -S 424155071543201 04/27/2007 42.1 0.52 0.08 0.21 4.7

Route 119 -S 424155071543201 06/03/2007 -- 0.65 0.03 0.03 1.4

Route 119 -S 424155071543201 07/11/2007 0.71 0.32 0.03 0.03 2

Route 119 -S 424155071543201 08/03/2007 6.33 -- -- -- --

Route 8 -T 424019073062601 04/22/2006 1.08 0.42 0.03 E0.03 5

Route 8 -T 424019073062601 06/23/2006 3.36 1.11 0.07 0.07 3.4

Route 8 -T 424019073062601 09/23/2006 5.71 0.99 0.06 E0.04 2.9

Route 8 -T 424019073062601 12/01/2006 1.91 0.94 0.18 0.23 7.8

Route 8 -T 424019073062601 03/02/2007 55.6 1.22 0.21 0.89 34
136 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Sulfate,

dissolved

(mg/L)

Total nitrogen 

(nitrate + nitrite 

+ ammonia + 

organic-N),

total

(mg/L)

Phosphorus, 

total

(mg/L)

Cadmium,

total

(μg/L)

Chromium,

total,

recoverable

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 10 1.78 0.16 0.25 13

Interstate 190 -T 423016071431501 09/29/2005 4.51 0.89 0.14 0.17 14

Interstate 190 -T 423016071431501 10/07/2005 2.02 0.52 0.05 0.06 7.3

Interstate 190 -T 423016071431501 10/22/2005 5.2 1.24 0.04 0.1 6.7

Interstate 190 -T 423016071431501 10/24/2005 1.04 0.21 E0.01 E0.03 2.3

Interstate 190 -T 423016071431501 03/13/2006 306 2.83 0.4 2.4 58

Route 2 -P 423027071291301 09/15/2005 7.91 4.42 0.15 0.43 13

Route 2 -P 423027071291301 09/29/2005 3.33 1.07 0.16 0.49 17

Route 2 -P 423027071291301 10/22/2005 3.17 1.09 0.05 0.14 7.8

Route 2 -P 423027071291301 10/24/2005 1.23 0.32 0.02 0.08 2

Route 2 -P 423027071291301 01/11/2006 79.6 1.38 0.2 0.66 24

Route 2 -P 423027071291301 01/18/2006 36.7 0.84 0.16 0.47 20

Route 2 -P 423027071291301 03/13/2006 33.2 1.59 0.29 0.88 31

Route 2 -P 423027071291301 05/09/2006 5.65 1.09 0.06 0.24 13

Route 2 -P 423027071291301 06/02/2006 1.7 0.66 0.12 0.19 8.9

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 1.98 0.57 0.05 0.12 3

Route 2 -P 423027071291301 08/27/2006 3.18 0.69 E0.009 0.13 9.3

Route 2 -P 423027071291301 09/19/2006 3.52 0.97 0.06 0.17 6.3

Route 2 -P 423027071291301 11/07/2006 3.23 1.16 0.04 0.14 5.1

Route 2 -P 423027071291301 01/08/2007 4.14 0.68 0.05 0.17 13

Route 2 -P 423027071291301 03/02/2007 528 2.65 0.34 2.34 50

Route 2 -P 423027071291301 04/12/2007 72.8 1.51 0.32 0.76 47

Route 2 -P 423027071291301 08/06/2007 -- 2.34 0.11 0.32 12

Route 2 -P 423027071291301 08/08/2007 5.8 2.56 0.13 0.3 22

Route 2 -P 423027071291301 09/10/2007 3.76 -- -- -- --

Route 2 -S 423027071291302 08/20/2006 2.25 1.08 0.08 0.08 4.8

Route 2 -S 423027071291302 08/27/2006 3.4 0.73 0.02 0.05 7.9

Route 2 -S 423027071291302 09/19/2006 3.21 1.16 0.13 0.1 11

Route 2 -S 423027071291302 12/01/2006 2.35 0.74 0.15 0.16 14

Route 2 -S 423027071291302 01/08/2007 3.91 0.57 0.05 0.07 6.3

Route 2 -S 423027071291302 03/17/2007 402 1.74 0.11 3.08 16

Route 2 -S 423027071291302 04/12/2007 55.9 1.04 0.17 0.35 26

Route 2 -S 423027071291302 05/16/2007 3.2 1.36 0.14 0.13 17

Route 2 -S 423027071291302 08/08/2007 5.39 2.44 0.16 0.16 16
Tables 16–21 137

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Sulfate,

dissolved

(mg/L)

Total nitrogen 

(nitrate + nitrite 

+ ammonia + 

organic-N),

total

(mg/L)

Phosphorus, 

total

(mg/L)

Cadmium,

total

(μg/L)

Chromium,

total,

recoverable

(μg/L)

Route 2 -S 423027071291302 08/06/2007 8.21 2.9 0.23 0.19 12

Interstate 195 -T 414339070462201 04/23/2006 2.46 0.65 0.04 0.06 7.6

Interstate 195 -T 414339070462201 06/24/2006 2.46 0.98 0.04 0.09 2.6

Interstate 195 -T 414339070462201 09/29/2006 2.26 0.8 0.04 0.08 2.8

Interstate 195 -T 414339070462201 12/01/2006 4.35 1.52 0.06 0.1 4.8

Interstate 195 -T 414339070462201 02/14/2007 5.85 0.44 0.06 0.27 9.3

Interstate 495 -P 422821071332001 09/15/2005 8.71 3.07 0.19 0.41 11

Interstate 495 -P 422821071332001 09/29/2005 2.85 0.99 0.17 0.35 19

Interstate 495 -P 422821071332001 10/22/2005 1.17 0.39 0.02 0.08 3.4

Interstate 495 -P 422821071332001 10/24/2005 1.21 0.31 0.02 0.07 4.4

Interstate 495 -P 422821071332001 01/11/2006 38.3 1.58 0.39 1.07 47

Interstate 495 -P 422821071332001 03/13/2006 74.2 2.36 0.68 1.15 42

Interstate 495 -P 422821071332001 05/09/2006 5.66 1.12 0.1 0.2 8.7

Interstate 495 -P 422821071332001 06/02/2006 4.83 1.41 0.21 0.61 13

Interstate 495 -P 422821071332001 08/20/2006 2.38 0.97 0.1 0.11 4.2

Interstate 495 -P 422821071332001 08/27/2006 2.53 0.67 E0.01 0.08 8.1

Interstate 495 -P 422821071332001 09/19/2006 3.81 1.2 0.14 0.17 6.7

Interstate 495 -P 422821071332001 11/12/2006 1.87 0.48 0.08 0.13 9.1

Interstate 495 -P 422821071332001 01/08/2007 6.22 0.67 0.04 0.14 6.5

Interstate 495 -P 422821071332001 03/02/2007 296 1.77 0.42 1.72 53

Interstate 495 -P 422821071332001 04/12/2007 75.6 1.24 0.25 1.79 35

Interstate 495 -P 422821071332001 08/06/2007 -- 2.84 0.2 0.34 16

Interstate 495 -P 422821071332001 08/08/2007 6.43 2.25 0.13 0.31 12

Interstate 495 -P 422821071332001 09/10/2007 4.3 -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 9.96 3.37 0.18 0.38 18

Interstate 495 -S 422716071343901 09/29/2005 3.83 0.98 0.08 0.18 12

Interstate 495 -S 422716071343901 10/22/2005 4.3 1.2 0.03 0.16 7.7

Interstate 495 -S 422716071343901 10/24/2005 1.61 0.39 E0.02 0.08 4.3

Interstate 495 -S 422716071343901 01/11/2006 83.7 1.72 0.24 1.43 32

Interstate 495 -S 422716071343901 01/18/2006 31.8 1.09 0.16 1.17 21

Interstate 495 -S 422716071343901 03/13/2006 94.3 1.95 0.23 0.93 29

Interstate 495 -S 422716071343901 05/09/2006 5.48 1.1 0.06 0.2 8.2

Interstate 495 -S 422716071343901 06/02/2006 2.01 0.53 0.03 0.1 8.5

Interstate 495 -S 422716071343901 08/20/2006 2.62 0.77 0.04 0.13 5.6

Interstate 495 -S 422716071343901 09/19/2006 3.77 0.98 0.05 0.15 6.9
138 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Sulfate,

dissolved

(mg/L)

Total nitrogen 

(nitrate + nitrite 

+ ammonia + 

organic-N),

total

(mg/L)

Phosphorus, 

total

(mg/L)

Cadmium,

total

(μg/L)

Chromium,

total,

recoverable

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 8.62 1.54 0.13 0.25 24

Interstate 95 -P 422620071153301 09/29/2005 10.8 1.37 0.12 0.26 15

Interstate 95 -P 422620071153301 10/22/2005 -- 1.46 0.03 0.06 4.7

Interstate 95 -P 422620071153301 11/16/2005 -- 1.19 0.05 0.08 4.9

Interstate 95 -P 422620071153301 01/12/2006 125 3.74 0.31 2.4 89

Interstate 95 -P 422620071153301 01/18/2006 19.8 1.58 0.23 1.03 39

Interstate 95 -P 422620071153301 03/13/2006 468 6.12 0.54 5.7 73

Interstate 95 -P 422620071153301 05/09/2006 9.18 1.52 0.13 0.16 21

Interstate 95 -P 422620071153301 06/02/2006 5.12 0.95 0.09 0.09 9

Interstate 95 -P 422620071153301 08/20/2006 6.02 0.8 0.04 0.06 4

Interstate 95 -P 422620071153301 08/27/2006 6.16 0.89 0.03 0.05 7.2

Interstate 95 -P 422620071153301 09/19/2006 6.87 1.12 0.07 0.11 9.9

Interstate 95 -P 422620071153301 10/20/2006 6.28 -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 3.25 -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 3.8 1.25 0.1 0.37 9.7

Interstate 95 -P 422620071153301 03/11/2007 364 3.32 0.15 2.63 16

Interstate 95 -P 422620071153301 03/17/2007 214 1.75 0.38 1.31 47

Interstate 95 -P 422620071153301 04/12/2007 43.6 2.05 0.2 0.69 29

Interstate 95 -P 422620071153301 08/06/2007 12.4 2.32 0.21 0.08 11

Interstate 95 -P 422620071153301 08/08/2007 13.1 2.38 0.16 0.1 8.3

Interstate 95 -S 422420071153302 08/20/2006 3.39 1.02 0.05 0.17 3.1

Interstate 95 -S 422420071153302 08/27/2006 4 1.04 E0.01 0.15 11

Interstate 95 -S 422420071153302 09/19/2006 6.24 1.65 0.06 0.23 6.1

Interstate 95 -S 422420071153302 11/07/2006 3.33 1.15 0.06 0.11 5.9

Interstate 95 -S 422420071153302 03/02/2007 76.9 2.62 0.36 3.05 40

Interstate 95 -S 422420071153302 03/17/2007 154 1.54 0.27 1.34 28

Interstate 95 -S 422420071153302 04/12/2007 8.85 1.3 0.2 0.42 27

Interstate 95 -S 422420071153302 05/16/2007 4.35 2.8 0.33 0.3 27

Interstate 95 -S 422420071153302 08/06/2007 9.82 4.07 0.41 0.53 16

Interstate 95 -S 422420071153302 08/08/2007 10.9 3.89 0.15 0.28 39

Interstate 93 -T 421647071024703 04/23/2006 17.4 1.71 0.13 0.45 26

Interstate 93 -T 421647071024703 06/23/2006 5.13 2.09 0.71 1.69 100

Interstate 93 -T 421647071024703 09/19/2006 4.84 1.1 0.11 0.17 13

Interstate 93 -T 421647071024703 12/01/2006 10.2 2.32 0.34 0.78 40

Interstate 93 -T 421647071024703 02/14/2007 257 4 1 4 110
Tables 16–21 139

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Copper,

total,

recoverable 

(μg/L)

Iron,

total,

recoverable 

(μg/L)

Lead,

total,

recoverable 

(μg/L)

Manganese, 

total,

recoverable 

(μg/L)

Nickel,

total,

recoverable 

(μg/L)

Route 119 -P 424209071545201 09/15/2005 18.7 467 2 83.5 5.69

Route 119 -P 424209071545201 09/29/2005 4.97 824 2.1 17.7 1.25

Route 119 -P 424209071545201 10/22/2005 2.13 186 0.6 13.7 0.55

Route 119 -P 424209071545201 10/24/2005 1.1 112 0.3 6.1 0.25

Route 119 -P 424209071545201 01/11/2006 27.4 9,750 20.2 171 12.5

Route 119 -P 424209071545201 01/18/2006 17.2 7,330 19.3 129 8.31

Route 119 -P 424209071545201 03/13/2006 50.2 23,900 40.7 312 22.7

Route 119 -P 424209071545201 05/09/2006 7.46 441 1.3 22.8 1.64

Route 119 -P 424209071545201 06/01/2006 17.4 3,780 9.8 82.4 6.24

Route 119 -P 424209071545201 09/14/2006 5.64 367 1.1 11.6 1.11

Route 119 -P 424209071545201 09/19/2006 6.68 186 0.7 25.9 1.66

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 1.68 100 0.4 4.5 0.34

Route 119 -P 424209071545201 11/12/2006 -- -- -- -- --

Route 119 -P 424209071545201 01/08/2007 5.08 810 2.4 14.3 1.18

Route 119 -P 424209071545201 04/01/2007 8.26 1,350 3.6 27.8 4.45

Route 119 -P 424209071545201 04/14/2007 11.4 3,610 6.9 74.1 4.59

Route 119 -P 424209071545201 06/03/2007 3.62 294 0.8 9.9 0.83

Route 119 -P 424209071545201 07/11/2007 3.75 654 1.4 16.7 1.16

Route 119 -S 424155071543201 09/29/2005 4.62 1,030 2.6 19.8 1.29

Route 119 -S 424155071543201 10/24/2005 0.76 94 0.3 7.5 0.2

Route 119 -S 424155071543201 01/11/2006 29.9 10,400 22.4 179 12.4

Route 119 -S 424155071543201 01/18/2006 15.9 5,630 16 104 6.59

Route 119 -S 424155071543201 03/13/2006 39.9 16,900 32.5 224 15.9

Route 119 -S 424155071543201 08/20/2006 2.12 629 0.9 20.3 0.64

Route 119 -S 424155071543201 11/08/2006 1.68 319 0.6 8.2 0.38

Route 119 -S 424155071543201 04/27/2007 9.89 2,780 6.4 80.5 3.31

Route 119 -S 424155071543201 06/03/2007 4.54 456 1 16.2 0.95

Route 119 -S 424155071543201 07/11/2007 3.3 606 1.2 12.8 0.76

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 5.45 546 2.6 21.3 1.12

Route 8 -T 424019073062601 06/23/2006 10.7 842 4.9 39.6 2.08

Route 8 -T 424019073062601 09/23/2006 6.71 9 0.1 0.9 1.02

Route 8 -T 424019073062601 12/01/2006 32.4 3,580 21.7 115 4.48

Route 8 -T 424019073062601 03/02/2007 51.2 9,760 49.3 234 18.9
140 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Copper,

total,

recoverable 

(μg/L)

Iron,

total,

recoverable 

(μg/L)

Lead,

total,

recoverable 

(μg/L)

Manganese, 

total,

recoverable 

(μg/L)

Nickel,

total,

recoverable 

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 25.9 2,360 8.3 70.8 6.21

Interstate 190 -T 423016071431501 09/29/2005 26.7 2,950 8.6 62.6 5.23

Interstate 190 -T 423016071431501 10/07/2005 10.7 681 2.3 21.4 1.84

Interstate 190 -T 423016071431501 10/22/2005 12.5 606 1.4 88.2 2.45

Interstate 190 -T 423016071431501 10/24/2005 4.7 415 1.5 14.7 0.88

Interstate 190 -T 423016071431501 03/13/2006 140 21,800 67.9 390 33.5

Route 2 -P 423027071291301 09/15/2005 44.3 1,360 8 64 6.03

Route 2 -P 423027071291301 09/29/2005 34.6 2,930 12.7 64.6 4.59

Route 2 -P 423027071291301 10/22/2005 12.9 725 3 33.9 1.66

Route 2 -P 423027071291301 10/24/2005 5.18 298 1.5 15.8 0.74

Route 2 -P 423027071291301 01/11/2006 65.6 9,990 39.1 213 15.6

Route 2 -P 423027071291301 01/18/2006 39.9 7,060 30.3 121 8.54

Route 2 -P 423027071291301 03/13/2006 82.2 13,200 47.4 205 16.6

Route 2 -P 423027071291301 05/09/2006 20.9 1,080 4.8 33.3 2.52

Route 2 -P 423027071291301 06/02/2006 23 2,220 6.6 35.3 2.82

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 15.8 1,090 3.2 18.8 1.52

Route 2 -P 423027071291301 08/27/2006 7.24 187 1.1 12.8 0.9

Route 2 -P 423027071291301 09/19/2006 13 841 3.1 27.4 1.95

Route 2 -P 423027071291301 11/07/2006 10.4 258 1.6 20.3 1

Route 2 -P 423027071291301 01/08/2007 19.8 1,320 6.3 25.4 2.12

Route 2 -P 423027071291301 03/02/2007 108 16,600 60 325 37.9

Route 2 -P 423027071291301 04/12/2007 83.7 12,100 43.6 185 15.7

Route 2 -P 423027071291301 08/06/2007 37.2 1,970 9.8 69.2 5.01

Route 2 -P 423027071291301 08/08/2007 32.4 2,110 10.2 56.6 4.53

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 12.9 665 3.5 22.6 1.67

Route 2 -S 423027071291302 08/27/2006 8.57 307 1.6 16.6 0.95

Route 2 -S 423027071291302 09/19/2006 20.9 1,860 6.1 38.1 2.93

Route 2 -S 423027071291302 12/01/2006 44.4 3,520 16 65.9 4.44

Route 2 -S 423027071291302 01/08/2007 17.6 955 5.1 20.7 1.65

Route 2 -S 423027071291302 03/17/2007 70.9 4,110 13.1 217 50

Route 2 -S 423027071291302 04/12/2007 50.2 7,050 21.1 100 8

Route 2 -S 423027071291302 05/16/2007 25.5 2,170 9.4 42.6 3.42

Route 2 -S 423027071291302 08/08/2007 46.9 2,360 10.9 64.7 6.81
Tables 16–21 141

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Copper,

total,

recoverable 

(μg/L)

Iron,

total,

recoverable 

(μg/L)

Lead,

total,

recoverable 

(μg/L)

Manganese, 

total,

recoverable 

(μg/L)

Nickel,

total,

recoverable 

(μg/L)

Route 2 -S 423027071291302 08/06/2007 30 2,730 13.8 86.5 7.02

Interstate 195 -T 414339070462201 04/23/2006 16.3 1,380 8.2 18.6 2.5

Interstate 195 -T 414339070462201 06/24/2006 11 527 3.2 13.6 1.62

Interstate 195 -T 414339070462201 09/29/2006 28.1 542 3.1 13.1 1.5

Interstate 195 -T 414339070462201 12/01/2006 17.7 947 7.3 22.6 2.35

Interstate 195 -T 414339070462201 02/14/2007 24.6 1,690 10.7 30.3 5.38

Interstate 495 -P 422821071332001 09/15/2005 64.9 1,740 8.7 71.5 7.65

Interstate 495 -P 422821071332001 09/29/2005 59.3 7,640 20.9 92.8 7.24

Interstate 495 -P 422821071332001 10/22/2005 10.7 868 3.2 18.3 1.47

Interstate 495 -P 422821071332001 10/24/2005 11.5 840 3 18 1.44

Interstate 495 -P 422821071332001 01/11/2006 164 28,000 76.2 459 29.9

Interstate 495 -P 422821071332001 03/13/2006 155 20,200 69.7 303 24.2

Interstate 495 -P 422821071332001 05/09/2006 29 1,530 5.9 39.4 2.98

Interstate 495 -P 422821071332001 06/02/2006 45.1 7,240 10.6 114 6.83

Interstate 495 -P 422821071332001 08/20/2006 16.5 1,110 3.6 23 1.84

Interstate 495 -P 422821071332001 08/27/2006 12.4 561 2.1 16.5 1.31

Interstate 495 -P 422821071332001 09/19/2006 29.2 1,670 7 42 3.03

Interstate 495 -P 422821071332001 11/12/2006 23.9 1,720 7.4 29.4 2.39

Interstate 495 -P 422821071332001 01/08/2007 22.4 1,370 5.8 28.9 2.24

Interstate 495 -P 422821071332001 03/02/2007 166 21,600 75.5 328 34.6

Interstate 495 -P 422821071332001 04/12/2007 89.4 11,500 53.5 184 15.6

Interstate 495 -P 422821071332001 08/06/2007 55.2 3,680 14.3 85.7 7

Interstate 495 -P 422821071332001 08/08/2007 49 3,310 12.6 77 6.46

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 62 1,870 12.1 75.6 8.85

Interstate 495 -S 422716071343901 09/29/2005 25.3 1,460 8.8 34.2 3.23

Interstate 495 -S 422716071343901 10/22/2005 14.2 591 2.9 23.2 1.9

Interstate 495 -S 422716071343901 10/24/2005 9.64 627 2.5 14.6 1.12

Interstate 495 -S 422716071343901 01/11/2006 90.3 13,800 47.5 299 21.4

Interstate 495 -S 422716071343901 01/18/2006 53.6 8,660 32.2 175 12.3

Interstate 495 -S 422716071343901 03/13/2006 82 10,900 41.6 198 15.7

Interstate 495 -S 422716071343901 05/09/2006 25.1 1,420 6.9 40.2 2.9

Interstate 495 -S 422716071343901 06/02/2006 12.9 1,090 4.5 20.5 1.71

Interstate 495 -S 422716071343901 08/20/2006 12.9 688 5.5 19 1.78

Interstate 495 -S 422716071343901 09/19/2006 16.2 727 2.7 24.2 1.99
142 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Copper,

total,

recoverable 

(μg/L)

Iron,

total,

recoverable 

(μg/L)

Lead,

total,

recoverable 

(μg/L)

Manganese, 

total,

recoverable 

(μg/L)

Nickel,

total,

recoverable 

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 58.7 1,440 18.2 62.7 4.7

Interstate 95 -P 422620071153301 09/29/2005 40.4 3,620 31.4 65 4.78

Interstate 95 -P 422620071153301 10/22/2005 9.37 451 2.4 19.9 1.08

Interstate 95 -P 422620071153301 11/16/2005 18 536 3.8 27.5 1.88

Interstate 95 -P 422620071153301 01/12/2006 167 15,100 85.5 493 28.4

Interstate 95 -P 422620071153301 01/18/2006 111 10,100 67.9 231 16

Interstate 95 -P 422620071153301 03/13/2006 236 20,600 120 594 36.4

Interstate 95 -P 422620071153301 05/09/2006 59 2,450 14.9 59.1 4.38

Interstate 95 -P 422620071153301 06/02/2006 33.6 1,230 8.4 35.2 2.58

Interstate 95 -P 422620071153301 08/20/2006 18.2 389 3.2 29.7 1.66

Interstate 95 -P 422620071153301 08/27/2006 16.8 328 2.2 21.5 1.3

Interstate 95 -P 422620071153301 09/19/2006 26 1,280 13.2 43.1 2.39

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 33.8 1,690 46.2 34.1 3.28

Interstate 95 -P 422620071153301 03/11/2007 87.6 3,810 21.9 288 16.2

Interstate 95 -P 422620071153301 03/17/2007 123 11,800 54 263 27.3

Interstate 95 -P 422620071153301 04/12/2007 87.6 6,470 36.1 152 10.5

Interstate 95 -P 422620071153301 08/06/2007 44.6 1,160 14.4 53.6 4.26

Interstate 95 -P 422620071153301 08/08/2007 64.1 1,200 17.3 58.9 3.72

Interstate 95 -S 422420071153302 08/20/2006 10.3 414 2.3 17.1 2.85

Interstate 95 -S 422420071153302 08/27/2006 11.5 386 1.7 13.6 1.99

Interstate 95 -S 422420071153302 09/19/2006 18.6 593 2.8 25.6 4.36

Interstate 95 -S 422420071153302 11/07/2006 17.4 702 3.3 29 2.14

Interstate 95 -S 422420071153302 03/02/2007 103 12,600 46.2 254 25

Interstate 95 -S 422420071153302 03/17/2007 68.8 8,920 30.1 179 23.4

Interstate 95 -S 422420071153302 04/12/2007 52.8 5,320 19.5 81.1 9.2

Interstate 95 -S 422420071153302 05/16/2007 60 4,870 21.4 95.3 8

Interstate 95 -S 422420071153302 08/06/2007 42.7 4,230 19.3 120 7.81

Interstate 95 -S 422420071153302 08/08/2007 88.9 1,910 13.7 76.3 12.5

Interstate 93 -T 421647071024703 04/23/2006 91.4 4,060 35.1 84.5 6.84

Interstate 93 -T 421647071024703 06/23/2006 263 38,500 120 819 35.3

Interstate 93 -T 421647071024703 09/19/2006 56.4 3,380 17.8 81.2 4.49

Interstate 93 -T 421647071024703 12/01/2006 178 12,100 75.6 220 18.2

Interstate 93 -T 421647071024703 02/14/2007 538 27,200 366 535 48
Tables 16–21 143

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Zinc,

total,

recoverable 

(μg/L)

Fluorene,

total,

recoverable 

(μg/L)

Acenaphthene, 

total,

recoverable 

(μg/L)

Acenaphthylene,

total,

recoverable 

(μg/L)

Anthracene, 

total,

recoverable 

(μg/L)

Route 119 -P 424209071545201 09/15/2005 82.5 <2 <2 <2 <2

Route 119 -P 424209071545201 09/29/2005 25.4 <2 <2 <2 E0.02

Route 119 -P 424209071545201 10/22/2005 16.1 -- -- -- --

Route 119 -P 424209071545201 10/24/2005 8 -- -- -- --

Route 119 -P 424209071545201 01/11/2006 188 E0.06 E0.02 E0.04 E0.07

Route 119 -P 424209071545201 01/18/2006 145 E0.04 E0.02 E0.04 E0.05

Route 119 -P 424209071545201 03/13/2006 293 <80 <72 <96 <80

Route 119 -P 424209071545201 05/09/2006 25.6 <0.33 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 06/01/2006 107 <0.33 <0.28 E0.0240 E0.0316

Route 119 -P 424209071545201 09/14/2006 17.8 <0.33 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 09/19/2006 29.7 <0.33 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 9.4 E0.0057 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 11/12/2006 -- E0.0057 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 01/08/2007 23.6 E0.0073 E0.0027 E0.0096 E0.0116

Route 119 -P 424209071545201 04/01/2007 58.5 E0.0205 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 04/14/2007 72.4 E0.0128 E0.0052 E0.0104 E0.0199

Route 119 -P 424209071545201 06/03/2007 14.7 <0.33 <0.28 <0.30 <0.39

Route 119 -P 424209071545201 07/11/2007 19.8 <0.33 <0.28 <0.30 <0.39

Route 119 -S 424155071543201 09/29/2005 26.7 <2 <2 <2 <2

Route 119 -S 424155071543201 10/24/2005 8 <2 <2 <2 <2

Route 119 -S 424155071543201 01/11/2006 249 E0.05 E0.03 E0.05 E0.09

Route 119 -S 424155071543201 01/18/2006 91.4 E0.03 E0.01 E0.03 E0.05

Route 119 -S 424155071543201 03/13/2006 202 <80 <72 <96 <80

Route 119 -S 424155071543201 08/20/2006 21.2 <0.33 <0.28 <0.30 <0.39

Route 119 -S 424155071543201 11/08/2006 14.6 <0.33 <0.28 <0.30 <0.39

Route 119 -S 424155071543201 04/27/2007 187 E0.0131 E0.0043 E0.0195 E0.0200

Route 119 -S 424155071543201 06/03/2007 25.4 <0.33 <0.28 <0.30 <0.39

Route 119 -S 424155071543201 07/11/2007 17.1 <0.33 <0.28 <0.30 <0.39

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 21.5 E0.0100 <0.28 <0.30 E0.0131

Route 8 -T 424019073062601 06/23/2006 30.5 <0.33 <0.28 <0.30 <0.39

Route 8 -T 424019073062601 09/23/2006 9.2 E0.0100 <0.28 E0.0173 E0.0125

Route 8 -T 424019073062601 12/01/2006 107 E0.0176 E0.0083 E0.0290 E0.0518

Route 8 -T 424019073062601 03/02/2007 301 E0.0317 <0.28 E0.0419 E0.0444
144 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Zinc,

total,

recoverable 

(μg/L)

Fluorene,

total,

recoverable 

(μg/L)

Acenaphthene, 

total,

recoverable 

(μg/L)

Acenaphthylene,

total,

recoverable 

(μg/L)

Anthracene, 

total,

recoverable 

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 171 <2 <2 <2 <2

Interstate 190 -T 423016071431501 09/29/2005 103 E0.02 <2 <2 E0.04

Interstate 190 -T 423016071431501 10/07/2005 37.7 <2 <2 <2 E0.01

Interstate 190 -T 423016071431501 10/22/2005 59.2

Interstate 190 -T 423016071431501 10/24/2005 23.6 E0.01 <2 <2 E0.01

Interstate 190 -T 423016071431501 03/13/2006 630 <40 E0.1 <48 E0.2

Route 2 -P 423027071291301 09/15/2005 402 <2 <2 <2 <2

Route 2 -P 423027071291301 09/29/2005 420 E0.03 <2 <2 E0.06

Route 2 -P 423027071291301 10/22/2005 182 E0.02 <2 <2 <2

Route 2 -P 423027071291301 10/24/2005 119 E0.01 <2 E0.01 <2

Route 2 -P 423027071291301 01/11/2006 1,100 E0.09 E0.04 E0.07 E0.09

Route 2 -P 423027071291301 01/18/2006 647 E0.06 E0.03 E0.04 E0.08

Route 2 -P 423027071291301 03/13/2006 926 E0.04 E0.02 E0.02 E0.05

Route 2 -P 423027071291301 05/09/2006 266 <0.33 <0.28 <0.30 <0.39

Route 2 -P 423027071291301 06/02/2006 195 <0.33 E0.0069 E0.0156 E0.0222

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 128 E0.0091 <0.28 E0.0090 E0.0125

Route 2 -P 423027071291301 08/27/2006 131 -- -- -- --

Route 2 -P 423027071291301 09/19/2006 166 E0.0144 <0.28 <0.30 E0.0182

Route 2 -P 423027071291301 11/07/2006 194 E0.0105 <0.28 <0.30 <0.39

Route 2 -P 423027071291301 01/08/2007 237 E0.0166 E0.0068 <0.30 E0.0203

Route 2 -P 423027071291301 03/02/2007 1,130 E0.142 E0.0555 E0.0634 E0.144

Route 2 -P 423027071291301 04/12/2007 833 E0.0908 E0.0466 E0.0533 E0.127

Route 2 -P 423027071291301 08/06/2007 382 <0.33 <0.28 E0.0371 <0.39

Route 2 -P 423027071291301 08/08/2007 350 <0.33 <0.28 <0.30 E0.0504

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 76 <0.33 <0.28 E0.0138 <0.39

Route 2 -S 423027071291302 08/27/2006 55 <0.33 <0.28 <0.30 <0.39

Route 2 -S 423027071291302 09/19/2006 128 E0.0133 <0.28 <0.30 E0.0242

Route 2 -S 423027071291302 12/01/2006 165 E0.0721 E0.0415 E0.0268 E0.147

Route 2 -S 423027071291302 01/08/2007 72 E0.0114 E0.0052 <0.30 E0.0284

Route 2 -S 423027071291302 03/17/2007 371 E0.0508 E0.0244 <0.30 <0.39

Route 2 -S 423027071291302 04/12/2007 228 E0.0688 E0.0258 E0.0251 E0.0855

Route 2 -S 423027071291302 05/16/2007 139 E0.0263 E0.0111 E0.0145 E0.0351

Route 2 -S 423027071291302 08/08/2007 207 <0.33 <0.28 <0.30 <0.39
Tables 16–21 145

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Zinc,

total,

recoverable 

(μg/L)

Fluorene,

total,

recoverable 

(μg/L)

Acenaphthene, 

total,

recoverable 

(μg/L)

Acenaphthylene,

total,

recoverable 

(μg/L)

Anthracene, 

total,

recoverable 

(μg/L)

Route 2 -S 423027071291302 08/06/2007 167 <0.33 <0.28 <0.30 <0.39

Interstate 195 -T 414339070462201 04/23/2006 52.8 E0.0190 <0.28 E0.0127 <0.39

Interstate 195 -T 414339070462201 06/24/2006 55.6 <33 <0.28 <0.30 <0.39

Interstate 195 -T 414339070462201 09/29/2006 52.9 E0.0183 <0.28 <0.30 E0.0135

Interstate 195 -T 414339070462201 12/01/2006 68.5 E0.0445 E0.0270 E0.0138 E0.104

Interstate 195 -T 414339070462201 02/14/2007 82.1 E0.0655 E0.0170 E0.0316 E0.0730

Interstate 495 -P 422821071332001 09/15/2005 211 <2 <2 <2 <2

Interstate 495 -P 422821071332001 09/29/2005 213 E0.05 E0.03 <2 E0.10

Interstate 495 -P 422821071332001 10/22/2005 51.9 E0.02 <2 E0.02 E0.02

Interstate 495 -P 422821071332001 10/24/2005 42.6 <2 <2 <2 E0.02

Interstate 495 -P 422821071332001 01/11/2006 687 E0.5 E0.3 E0.2 E0.8

Interstate 495 -P 422821071332001 03/13/2006 580 <80 E0.2 <96 E0.5

Interstate 495 -P 422821071332001 05/09/2006 90 E0.0143 E0.0078 <0.30 E0.0316

Interstate 495 -P 422821071332001 06/02/2006 131 E0.0318 E0.0214 E0.0243 E0.0775

Interstate 495 -P 422821071332001 08/20/2006 69 E0.0055 <0.28 E0.0178 E0.0110

Interstate 495 -P 422821071332001 08/27/2006 44.6 <0.33 <0.28 <0.30 E0.0099

Interstate 495 -P 422821071332001 09/19/2006 175 E0.0183 E0.0094 E0.0219 E0.0416

Interstate 495 -P 422821071332001 11/12/2006 96.7 E0.0306 E0.0114 E0.0160 E0.0504

Interstate 495 -P 422821071332001 01/08/2007 78.2 E0.0254 E0.0170 <0.30 E0.0633

Interstate 495 -P 422821071332001 03/02/2007 758 E0.300 E0.208 E0.0972 E0.526

Interstate 495 -P 422821071332001 04/12/2007 339 E0.100 E0.0622 E0.0304 E0.182

Interstate 495 -P 422821071332001 08/06/2007 293 <0.33 <0.28 E0.0507 E0.0584

Interstate 495 -P 422821071332001 08/08/2007 242 E0.0380 <0.28 E0.0352 E0.0999

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 238 <2 <2 <2 <2

Interstate 495 -S 422716071343901 09/29/2005 102 <2 <2 <2 E0.02

Interstate 495 -S 422716071343901 10/22/2005 73.1 <2 <2 <2 E0.02

Interstate 495 -S 422716071343901 10/24/2005 38.5 E0.02 <2 <2 <2

Interstate 495 -S 422716071343901 01/11/2006 537 E0.1 E0.05 E0.1 E0.1

Interstate 495 -S 422716071343901 01/18/2006 276 E0.07 E0.03 E0.05 E0.1

Interstate 495 -S 422716071343901 03/13/2006 413 <40 <36 <48 <40

Interstate 495 -S 422716071343901 05/09/2006 89.9 E0.0130 E0.0051 <0.30 E0.0127

Interstate 495 -S 422716071343901 06/02/2006 51.3 E0.0121 E0.0076 E0.0201 E0.0144

Interstate 495 -S 422716071343901 08/20/2006 64.6 E0.0072 <0.28 E0.0133 E0.0100

Interstate 495 -S 422716071343901 09/19/2006 84.3 E0.0153 <0.28 <0.30 E0.0169
146 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per

centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery

or variation in recovery of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified

as estimated; blue-shaded values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the 

monitoring sites for each test highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Zinc,

total,

recoverable 

(μg/L)

Fluorene,

total,

recoverable 

(μg/L)

Acenaphthene, 

total,

recoverable 

(μg/L)

Acenaphthylene,

total,

recoverable 

(μg/L)

Anthracene, 

total,

recoverable 

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 110 <2 <2 <2 E0.07

Interstate 95 -P 422620071153301 09/29/2005 228 E0.05 E0.03 E0.1 E0.1

Interstate 95 -P 422620071153301 10/22/2005 37.5 <2 <2 <2 E0.02

Interstate 95 -P 422620071153301 11/16/2005 51 <2 <2 <2 <2

Interstate 95 -P 422620071153301 01/12/2006 847 E0.08 E0.04 E0.08 E0.1

Interstate 95 -P 422620071153301 01/18/2006 509 E0.1 E0.08 E0.09 E0.3

Interstate 95 -P 422620071153301 03/13/2006 963 <80 E0.2 <96 E0.4

Interstate 95 -P 422620071153301 05/09/2006 122 E0.0206 <0.28 E0.0461 E0.0786

Interstate 95 -P 422620071153301 06/02/2006 79.4 <0.33 <0.28 E0.0170 E0.0315

Interstate 95 -P 422620071153301 08/20/2006 41 <0.33 <0.28 E0.0128 E0.0088

Interstate 95 -P 422620071153301 08/27/2006 35 <0.33 <0.28 <0.30 E0.0210

Interstate 95 -P 422620071153301 09/19/2006 83.3 <0.33 <0.28 E0.0363 E0.0385

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 108 E0.0249 E0.0129 E0.0194 E0.0428

Interstate 95 -P 422620071153301 03/11/2007 312 E0.0391 <0.28 <0.30 E0.151

Interstate 95 -P 422620071153301 03/17/2007 462 E0.116 E0.0751 <0.30 E0.205

Interstate 95 -P 422620071153301 04/12/2007 339 E0.0682 E0.0372 E0.0330 E0.118

Interstate 95 -P 422620071153301 08/06/2007 114 <0.33 <0.28 <0.30 <0.39

Interstate 95 -P 422620071153301 08/08/2007 101 <0.33 <0.28 E0.0480 <0.39

Interstate 95 -S 422420071153302 08/20/2006 68.3 <0.33 <0.28 <0.30 E0.0083

Interstate 95 -S 422420071153302 08/27/2006 48.5 <0.33 <0.28 <0.30 <0.39

Interstate 95 -S 422420071153302 09/19/2006 115 <0.33 <0.28 <0.30 E0.0205

Interstate 95 -S 422420071153302 11/07/2006 69.3 E0.0519 E0.0310 <0.30 E0.0750

Interstate 95 -S 422420071153302 03/02/2007 553 0.448 E0.270 E0.127 0.519

Interstate 95 -S 422420071153302 03/17/2007 336 E0.297 E0.211 <0.30 E0.343

Interstate 95 -S 422420071153302 04/12/2007 218 E0.146 E0.0964 <0.30 E0.192

Interstate 95 -S 422420071153302 05/16/2007 238 E0.0970 E0.0594 <0.30 E0.150

Interstate 95 -S 422420071153302 08/06/2007 208 <0.33 <0.28 E0.108 E0.100

Interstate 95 -S 422420071153302 08/08/2007 371 <0.33 <0.28 E0.0868 E0.0453

Interstate 93 -T 421647071024703 04/23/2006 301 E0.0566 E0.0217 E0.0497 E0.0983

Interstate 93 -T 421647071024703 06/23/2006 1,380 E0.139 E0.0954 E0.0869 E0.266

Interstate 93 -T 421647071024703 09/19/2006 180 E0.0212 E0.0146 E0.0263 E0.0617

Interstate 93 -T 421647071024703 12/01/2006 613 E0.115 E0.0668 E0.0666 E0.205

Interstate 93 -T 421647071024703 02/14/2007 1,870 E0.300 E0.184 <0.30 1
Tables 16–21 147

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzo[a]-

anthracene, 

total,

recoverable 

(μg/L)

Benzo[a]-

pyrene,

total,

recoverable 

(μg/L)

Benzo[b]fluoranthene,

total,

recoverable 

(μg/L)

Benzo[ghi]-

perylene,

total,

recoverable 

(μg/L)

Benzo[k]-

fluoranthene, 

total,

recoverable 

(μg/L)

Route 119 -P 424209071545201 09/15/2005 <2 <1 <2 E0.03 <2

Route 119 -P 424209071545201 09/29/2005 E0.04 E0.07 E0.1 E0.05 <2

Route 119 -P 424209071545201 10/22/2005 -- -- -- -- --

Route 119 -P 424209071545201 10/24/2005 -- -- -- -- --

Route 119 -P 424209071545201 01/11/2006 E0.2 E0.3 E0.7 E0.2 E0.2

Route 119 -P 424209071545201 01/18/2006 E0.2 E0.3 E0.6 E0.1 E0.2

Route 119 -P 424209071545201 03/13/2006 <96 E0.5 E0.6 E0.4 E0.2

Route 119 -P 424209071545201 05/09/2006 <0.26 <0.33 <0.40 E0.0209 <0.45

Route 119 -P 424209071545201 06/01/2006 E0.0911 E0.147 E0.255 E0.141 E0.0931

Route 119 -P 424209071545201 09/14/2006 <0.26 <0.33 <0.40 <0.64 <0.45

Route 119 -P 424209071545201 09/19/2006 <0.26 E0.0294 E0.0408 E0.0287 E0.0176

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 <0.26 <0.33 <0.40 <0.64 <0.45

Route 119 -P 424209071545201 11/12/2006 <0.26 E0.0380 E0.0600 E0.0387 <0.45

Route 119 -P 424209071545201 01/08/2007 E0.0336 E0.0417 E0.0764 E0.0461 E0.0246

Route 119 -P 424209071545201 04/01/2007 <0.26 E0.0695 E0.149 E0.0899 E0.0597

Route 119 -P 424209071545201 04/14/2007 E0.0606 E0.0970 E0.218 E0.0705 E0.0782

Route 119 -P 424209071545201 06/03/2007 <0.26 <0.33 <0.40 <0.64 <0.45

Route 119 -P 424209071545201 07/11/2007 <0.26 <0.33 E0.0440 E0.0256 <0.45

Route 119 -S 424155071543201 09/29/2005 E0.05 E0.08 E0.1 E0.06 <2

Route 119 -S 424155071543201 10/24/2005 <2 <1 <2 <3 <2

Route 119 -S 424155071543201 01/11/2006 E0.3 E0.4 E0.9 E0.2 E0.3

Route 119 -S 424155071543201 01/18/2006 E0.1 E0.2 E0.4 E0.1 E0.1

Route 119 -S 424155071543201 03/13/2006 <96 E0.4 E0.6 E0.4 E0.2

Route 119 -S 424155071543201 08/20/2006 <0.26 <0.33 <0.40 <0.64 <0.45

Route 119 -S 424155071543201 11/08/2006 <0.26 E0.0214 E0.0316 E0.0175 <0.45

Route 119 -S 424155071543201 04/27/2007 E0.0440 E0.0800 E0.160 E0.0410 E0.0517

Route 119 -S 424155071543201 06/03/2007 <0.26 <0.33 <0.40 <0.64 <0.45

Route 119 -S 424155071543201 07/11/2007 <0.26 <0.33 E0.0433 E0.0302 E0.0142

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 <0.26 E0.0366 E0.0564 E0.0329 E0.0223

Route 8 -T 424019073062601 06/23/2006 <0.26 <0.33 <0.40 E0.0572 <0.45

Route 8 -T 424019073062601 09/23/2006 E0.0406 E0.0770 E0.114 E0.0682 E0.0461

Route 8 -T 424019073062601 12/01/2006 E0.160 E0.218 E0.356 E0.125 E0.144

Route 8 -T 424019073062601 03/02/2007 <0.26 E0.176 E0.586 E0.163 <0.45
148 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzo[a]-

anthracene, 

total,

recoverable 

(μg/L)

Benzo[a]-

pyrene,

total,

recoverable 

(μg/L)

Benzo[b]fluoranthene,

total,

recoverable 

(μg/L)

Benzo[ghi]-

perylene,

total,

recoverable 

(μg/L)

Benzo[k]-

fluoranthene, 

total,

recoverable 

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 <2 <1 <2 E0.1 <2

Interstate 190 -T 423016071431501 09/29/2005 E0.1 E0.2 E0.4 E0.1 E0.1

Interstate 190 -T 423016071431501 10/07/2005 E0.03 E0.06 E0.1 E0.05 E0.05

Interstate 190 -T 423016071431501 10/22/2005 -- -- -- -- --

Interstate 190 -T 423016071431501 10/24/2005 E0.04 E0.04 E0.09 <3 <2

Interstate 190 -T 423016071431501 03/13/2006 E0.9 E1 E2 E1 E0.7

Route 2 -P 423027071291301 09/15/2005 E0.05 <1 E0.1 E0.08 E0.05

Route 2 -P 423027071291301 09/29/2005 E0.2 E0.2 E0.5 E0.2 E0.1

Route 2 -P 423027071291301 10/22/2005 E0.06 E0.08 E0.2 E0.07 E0.06

Route 2 -P 423027071291301 10/24/2005 <2 <1 E0.08 <3 E0.04

Route 2 -P 423027071291301 01/11/2006 E0.5 E0.6 E2 E0.4 E0.4

Route 2 -P 423027071291301 01/18/2006 E0.4 E0.5 E1 E0.3 E0.4

Route 2 -P 423027071291301 03/13/2006 E0.2 E0.3 E0.6 E0.2 E0.2

Route 2 -P 423027071291301 05/09/2006 E0.0659 E0.105 E0.201 E0.104 E0.0724

Route 2 -P 423027071291301 06/02/2006 E0.103 E0.144 E0.261 E0.197 E0.104

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 E0.0666 E0.0946 E0.172 E0.0831 E0.0567

Route 2 -P 423027071291301 08/27/2006 -- -- -- -- --

Route 2 -P 423027071291301 09/19/2006 E0.0868 E0.149 E0.261 E0.150 E0.0805

Route 2 -P 423027071291301 11/07/2006 <0.26 <0.33 <0.40 <0.64 <0.45

Route 2 -P 423027071291301 01/08/2007 E0.0804 E0.103 E0.192 E0.124 E0.0657

Route 2 -P 423027071291301 03/02/2007 E0.564 0.411 E1.11 E0.326 E0.328

Route 2 -P 423027071291301 04/12/2007 0.645 0.854 2.02 E0.518 E0.722

Route 2 -P 423027071291301 08/06/2007 E0.157 E0.260 0.508 E0.238 E0.199

Route 2 -P 423027071291301 08/08/2007 E0.254 E0.269 E0.562 <0.64 E0.184

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 <0.26 E0.0310 E0.0506 E0.0384 <0.45

Route 2 -S 423027071291302 08/27/2006 <0.26 E0.0344 E0.0655 <0.64 <0.45

Route 2 -S 423027071291302 09/19/2006 E0.118 E0.193 E0.324 E0.162 E0.130

Route 2 -S 423027071291302 12/01/2006 0.519 0.638 1.03 E0.367 E0.396

Route 2 -S 423027071291302 01/08/2007 E0.0702 E0.107 E0.187 E0.117 E0.0598

Route 2 -S 423027071291302 03/17/2007 0.351 0.467 1.1 E0.280 E0.400

Route 2 -S 423027071291302 04/12/2007 0.486 0.596 1.5 E0.352 E0.609

Route 2 -S 423027071291302 05/16/2007 E0.198 E0.266 0.566 E0.133 E0.222

Route 2 -S 423027071291302 08/08/2007 E0.179 E0.302 E0.495 E0.198 E0.181
Tables 16–21 149

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzo[a]-

anthracene, 

total,

recoverable 

(μg/L)

Benzo[a]-

pyrene,

total,

recoverable 

(μg/L)

Benzo[b]fluoranthene,

total,

recoverable 

(μg/L)

Benzo[ghi]-

perylene,

total,

recoverable 

(μg/L)

Benzo[k]-

fluoranthene, 

total,

recoverable 

(μg/L)

Route 2 -S 423027071291302 08/06/2007 E0.238 0.417 0.66 E0.301 E0.343

Interstate 195 -T 414339070462201 04/23/2006 E0.0705 E0.121 E0.285 E0.0892 E0.104

Interstate 195 -T 414339070462201 06/24/2006 <0.26 E0.0876 E0.122 E0.0843 E0.0656

Interstate 195 -T 414339070462201 09/29/2006 <0.26 E0.0851 E0.154 E0.0684 E0.0497

Interstate 195 -T 414339070462201 12/01/2006 E0.169 E0.273 E0.394 E0.144 E0.141

Interstate 195 -T 414339070462201 02/14/2007 E0.138 E0.110 E0.318 E0.123 E0.188

Interstate 495 -P 422821071332001 09/15/2005 E0.07 E0.10 E0.2 E0.1 E0.07

Interstate 495 -P 422821071332001 09/29/2005 E0.4 E0.5 E1 E0.4 E0.4

Interstate 495 -P 422821071332001 10/22/2005 E0.09 E0.1 E0.2 E0.08 E0.10

Interstate 495 -P 422821071332001 10/24/2005 E0.05 <1 E0.1 <3 <2

Interstate 495 -P 422821071332001 01/11/2006 E2 E2 E4 E1.0 E1

Interstate 495 -P 422821071332001 03/13/2006 E2 E3 E4 E2 E2

Interstate 495 -P 422821071332001 05/09/2006 E0.0970 E0.149 E0.254 E0.123 E0.0933

Interstate 495 -P 422821071332001 06/02/2006 0.281 E0.327 0.616 E0.270 E0.178

Interstate 495 -P 422821071332001 08/20/2006 E0.0513 E0.0828 E0.150 E0.0820 E0.0516

Interstate 495 -P 422821071332001 08/27/2006 E0.0319 E0.0438 E0.0757 E0.0357 E0.0337

Interstate 495 -P 422821071332001 09/19/2006 E0.172 E0.239 E0.391 E0.161 E0.139

Interstate 495 -P 422821071332001 11/12/2006 E0.197 E0.240 0.406 E0.167 E0.149

Interstate 495 -P 422821071332001 01/08/2007 E0.166 E0.188 E0.305 E0.186 E0.0966

Interstate 495 -P 422821071332001 03/02/2007 E1.33 E0.760 E1.55 E0.464 E0.477

Interstate 495 -P 422821071332001 04/12/2007 0.699 0.815 1.68 E0.424 E0.652

Interstate 495 -P 422821071332001 08/06/2007 0.29 0.471 0.79 E0.388 E0.292

Interstate 495 -P 422821071332001 08/08/2007 0.27 0.365 E0.564 E0.264 E0.190

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 E0.2 <1 E0.3 E0.1 E0.09

Interstate 495 -S 422716071343901 09/29/2005 E0.07 E0.1 E0.2 E0.10 E0.09

Interstate 495 -S 422716071343901 10/22/2005 <2 E0.08 E0.1 <3 E0.06

Interstate 495 -S 422716071343901 10/24/2005 E0.04 E0.06 E0.09 <3 E0.04

Interstate 495 -S 422716071343901 01/11/2006 E0.6 E0.7 E2 E0.4 E0.6

Interstate 495 -S 422716071343901 01/18/2006 E0.5 E0.6 E1 E0.3 E0.4

Interstate 495 -S 422716071343901 03/13/2006 E0.5 E0.5 E1 E0.7 E0.4

Interstate 495 -S 422716071343901 05/09/2006 E0.0465 E0.0826 E0.151 E0.0802 E0.0547

Interstate 495 -S 422716071343901 06/02/2006 E0.0722 E0.111 E0.183 E0.0874 E0.0662

Interstate 495 -S 422716071343901 08/20/2006 E0.0427 E0.0584 E0.111 E0.0721 E0.0364

Interstate 495 -S 422716071343901 09/19/2006 E0.0508 E0.0980 E0.166 E0.0911 E0.0547
150 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzo[a]-

anthracene, 

total,

recoverable 

(μg/L)

Benzo[a]-

pyrene,

total,

recoverable 

(μg/L)

Benzo[b]fluoranthene,

total,

recoverable 

(μg/L)

Benzo[ghi]-

perylene,

total,

recoverable 

(μg/L)

Benzo[k]-

fluoranthene, 

total,

recoverable 

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 E0.2 E0.3 E0.5 E0.2 E0.2

Interstate 95 -P 422620071153301 09/29/2005 E0.3 E0.3 E0.6 E0.2 E0.2

Interstate 95 -P 422620071153301 10/22/2005 E0.04 E0.06 E0.10 <3 E0.03

Interstate 95 -P 422620071153301 11/16/2005 E0.09 E0.1 E0.2 E0.06 E0.08

Interstate 95 -P 422620071153301 01/12/2006 E0.8 E1 E2 E0.7 E0.8

Interstate 95 -P 422620071153301 01/18/2006 E2 E2 E5 E1 2

Interstate 95 -P 422620071153301 03/13/2006 E3 E4 E8 E4 E2

Interstate 95 -P 422620071153301 05/09/2006 0.424 0.533 1.05 E0.364 E0.358

Interstate 95 -P 422620071153301 06/02/2006 E0.162 E0.230 0.476 E0.249 E0.165

Interstate 95 -P 422620071153301 08/20/2006 E0.0324 E0.0422 E0.0820 E0.0425 E0.0283

Interstate 95 -P 422620071153301 08/27/2006 E0.0619 E0.0734 E0.109 E0.0353 E0.0481

Interstate 95 -P 422620071153301 09/19/2006 E0.160 E0.228 0.404 E0.162 E0.140

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 E0.197 E0.286 0.444 E0.160 E0.187

Interstate 95 -P 422620071153301 03/11/2007 E0.291 0.433 E1.10 E0.420 E0.403

Interstate 95 -P 422620071153301 03/17/2007 1.11 E1.42 E3.14 E0.827 E1.15

Interstate 95 -P 422620071153301 04/12/2007 0.684 0.812 1.98 E0.582 E0.661

Interstate 95 -P 422620071153301 08/06/2007 <0.26 E0.147 E0.277 E0.127 E0.104

Interstate 95 -P 422620071153301 08/08/2007 E0.130 E0.184 E0.473 <0.64 E0.169

Interstate 95 -S 422420071153302 08/20/2006 E0.0473 E0.0676 E0.117 E0.0834 E0.0428

Interstate 95 -S 422420071153302 08/27/2006 E0.0295 E0.0417 E0.0814 E0.0372 E0.0347

Interstate 95 -S 422420071153302 09/19/2006 E0.0958 E0.158 E0.261 E0.143 E0.0994

Interstate 95 -S 422420071153302 11/07/2006 E0.148 E0.155 E0.248 E0.0971 E0.0970

Interstate 95 -S 422420071153302 03/02/2007 E2.49 1.5 E3.18 E1.02 E1.18

Interstate 95 -S 422420071153302 03/17/2007 1.07 E1.31 E2.78 E0.894 E0.993

Interstate 95 -S 422420071153302 04/12/2007 0.905 1.07 2.13 E0.600 E0.746

Interstate 95 -S 422420071153302 05/16/2007 0.732 0.881 1.76 E0.457 E0.543

Interstate 95 -S 422420071153302 08/06/2007 0.576 0.796 1.3 E0.551 0.748

Interstate 95 -S 422420071153302 08/08/2007 E0.235 E0.310 E0.584 E0.241 E0.293

Interstate 93 -T 421647071024703 04/23/2006 0.427 0.542 1.26 E0.343 E0.408

Interstate 93 -T 421647071024703 06/23/2006 E1.15 E1.36 E2.56 E0.662 E0.918

Interstate 93 -T 421647071024703 09/19/2006 0.28 0.364 0.679 E0.267 E0.298

Interstate 93 -T 421647071024703 12/01/2006 0.763 0.926 1.58 E0.490 0.626

Interstate 93 -T 421647071024703 02/14/2007 1 <1.89 E4.14 E1.00 E1.50
Tables 16–21 151

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzyl n-butyl 

phthalate,

total,

recoverable 

(μg/L)

Bis(2-ethylhexyl) 

phthalate,

total,

recoverable

(μg/L)

Chrysene,

total,

recoverable 

(μg/L)

Dibenzo[a,h]

anthracene, 

total,

recoverable 

(μg/L)

Diethyl

phthalate,

total,

recoverable

(μg/L)

Route 119 -P 424209071545201 09/15/2005 <1.26 <1.85 <3 <3 <0.61

Route 119 -P 424209071545201 09/29/2005 <1.26 <2.01 E0.08 <3 <0.61

Route 119 -P 424209071545201 10/22/2005 -- -- -- -- --

Route 119 -P 424209071545201 10/24/2005 -- -- -- -- --

Route 119 -P 424209071545201 01/11/2006 <1.26 E6.35 E0.6 <3 <0.61

Route 119 -P 424209071545201 01/18/2006 E14.6 E4.95 E0.3 <3 <0.61

Route 119 -P 424209071545201 03/13/2006 <50.4 <42 E0.4 <140 <24.4

Route 119 -P 424209071545201 05/09/2006 <1.26 <1.23 E0.0201 <0.70 <0.61

Route 119 -P 424209071545201 06/01/2006 <1.26 <1.57 E0.175 E0.0352 <0.61

Route 119 -P 424209071545201 09/14/2006 <1.26 E4.83 <0.33 <0.70 E0.176

Route 119 -P 424209071545201 09/19/2006 <1.26 E1.18 <0.33 <0.70 <0.61

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 <1.26 E1.73 <0.33 <0.70 <0.61

Route 119 -P 424209071545201 11/12/2006 <1.26 E3.54 <0.33 <0.70 <0.61

Route 119 -P 424209071545201 01/08/2007 <1.26 E1.31 E0.0627 <0.70 <0.61

Route 119 -P 424209071545201 04/01/2007 <1.26 E2.05 E0.127 <0.70 E0.166

Route 119 -P 424209071545201 04/14/2007 <1.26 E2.45 E0.112 <0.70 E0.128

Route 119 -P 424209071545201 06/03/2007 <1.26 <1.16 <0.33 <0.70 <0.61

Route 119 -P 424209071545201 07/11/2007 <1.26 <1.05 E0.0229 <0.70 <0.61

Route 119 -S 424155071543201 09/29/2005 <1.26 <1.71 E0.09 <3 <0.61

Route 119 -S 424155071543201 10/24/2005 <1.26 <1.05 <3 <3 <0.61

Route 119 -S 424155071543201 01/11/2006 <1.26 E4.79 E0.6 <3 <0.61

Route 119 -S 424155071543201 01/18/2006 E1.67 E4.14 E0.2 <3 <0.61

Route 119 -S 424155071543201 03/13/2006 <50.4 <42 E0.5 <140 <24.4

Route 119 -S 424155071543201 08/20/2006 <1.26 E0.652 <0.33 <0.70 E0.262

Route 119 -S 424155071543201 11/08/2006 <1.26 E0.866 <0.33 <0.70 <0.61

Route 119 -S 424155071543201 04/27/2007 <1.26 <1.67 E0.104 <0.70 <0.61

Route 119 -S 424155071543201 06/03/2007 <1.26 <1.05 <0.33 <0.70 <0.61

Route 119 -S 424155071543201 07/11/2007 <1.26 <1.05 E0.0305 <0.70 E0.466

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 <1.26 <1.44 E0.0320 <0.70 <0.61

Route 8 -T 424019073062601 06/23/2006 <1.26 <1.36 <0.33 <0.70 <0.61

Route 8 -T 424019073062601 09/23/2006 <1.26 E7.67 E0.0542 <0.70 <0.61

Route 8 -T 424019073062601 12/01/2006 E0.367 E4.89 E0.164 <0.70 E0.200

Route 8 -T 424019073062601 03/02/2007 <1.26 E12.6 E0.333 <0.70 <0.61
152 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzyl n-butyl 

phthalate,

total,

recoverable 

(μg/L)

Bis(2-ethylhexyl) 

phthalate,

total,

recoverable

(μg/L)

Chrysene,

total,

recoverable 

(μg/L)

Dibenzo[a,h]

anthracene, 

total,

recoverable 

(μg/L)

Diethyl

phthalate,

total,

recoverable

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 <1.26 <5.30 <3 <3 <0.61

Interstate 190 -T 423016071431501 09/29/2005 <1.26 E5.09 E0.2 <3 <0.61

Interstate 190 -T 423016071431501 10/07/2005 <1.26 E4.45 E0.06 <3 <0.61

Interstate 190 -T 423016071431501 10/22/2005 -- -- -- -- --

Interstate 190 -T 423016071431501 10/24/2005 <1.26 <1.52 E0.05 <3 <0.61

Interstate 190 -T 423016071431501 03/13/2006 <25.2 <21 E2 <68 <12.2

Route 2 -P 423027071291301 09/15/2005 <1.26 E5.60 E0.08 <3 <0.61

Route 2 -P 423027071291301 09/29/2005 <1.26 E5.35 E0.3 <3 <0.61

Route 2 -P 423027071291301 10/22/2005 <1.26 E3.50 E0.1 <3 <0.61

Route 2 -P 423027071291301 10/24/2005 <1.26 <1.70 <3 <3 <0.61

Route 2 -P 423027071291301 01/11/2006 <1.26 E9.15 E1 <3 <0.61

Route 2 -P 423027071291301 01/18/2006 E1.39 E13.8 E0.8 <3 <0.61

Route 2 -P 423027071291301 03/13/2006 <1.26 E3.91 E0.5 E0.06 <0.61

Route 2 -P 423027071291301 05/09/2006 <1.26 <2.67 E0.102 E0.0266 <0.61

Route 2 -P 423027071291301 06/02/2006 <1.26 <2.98 E0.201 E0.0512 <0.61

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 <1.26 1.37 E0.122 <0.70 E0.385

Route 2 -P 423027071291301 08/27/2006 -- E1.71 -- -- --

Route 2 -P 423027071291301 09/19/2006 <1.26 E2.58 E0.115 E0.0329 <0.61

Route 2 -P 423027071291301 11/07/2006 <1.26 E1.89 <0.33 <0.70 E0.192

Route 2 -P 423027071291301 01/08/2007 <1.26 E3.79 E0.119 <0.70 <0.61

Route 2 -P 423027071291301 03/02/2007 E1.14 E26.1 E1.49 <0.70 <0.61

Route 2 -P 423027071291301 04/12/2007 E0.759 E15.6 1.48 <0.70 <0.61

Route 2 -P 423027071291301 08/06/2007 <1.26 E5.60 0.375 <0.70 <0.61

Route 2 -P 423027071291301 08/08/2007 <1.26 E6.75 0.438 <0.70 <0.61

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 <1.26 E0.721 <0.33 <0.70 E0.210

Route 2 -S 423027071291302 08/27/2006 <1.26 E2.12 <0.33 <0.70 <0.61

Route 2 -S 423027071291302 09/19/2006 <1.26 E2.99 E0.197 E0.0512 <0.61

Route 2 -S 423027071291302 12/01/2006 E0.459 E7.00 0.786 E0.0983 E0.198

Route 2 -S 423027071291302 01/08/2007 <1.26 E2.87 E0.107 <0.70 <0.61

Route 2 -S 423027071291302 03/17/2007 <1.26 E6.97 0.801 <0.70 <0.61

Route 2 -S 423027071291302 04/12/2007 E0.593 E10.6 1.02 <0.70 E0.139

Route 2 -S 423027071291302 05/16/2007 <1.26 <10.2 0.368 <0.70 <0.61

Route 2 -S 423027071291302 08/08/2007 <1.26 E3.76 0.416 <0.70 <0.61
Tables 16–21 153

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzyl n-butyl 

phthalate,

total,

recoverable 

(μg/L)

Bis(2-ethylhexyl) 

phthalate,

total,

recoverable

(μg/L)

Chrysene,

total,

recoverable 

(μg/L)

Dibenzo[a,h]

anthracene, 

total,

recoverable 

(μg/L)

Diethyl

phthalate,

total,

recoverable

(μg/L)

Route 2 -S 423027071291302 08/06/2007 <1.26 E5.09 0.569 <0.70 <0.61

Interstate 195 -T 414339070462201 04/23/2006 <1.26 <4.99 E0.109 E0.0273 <0.61

Interstate 195 -T 414339070462201 06/24/2006 <1.26 <1.13 <0.33 <0.70 <0.61

Interstate 195 -T 414339070462201 09/29/2006 E1.49 E231 <0.33 <0.70 1.32

Interstate 195 -T 414339070462201 12/01/2006 <1.26 E5.41 E0.271 <0.70 <0.61

Interstate 195 -T 414339070462201 02/14/2007 <1.26 E3.82 E0.209 E0.0388 <0.61

Interstate 495 -P 422821071332001 09/15/2005 <1.26 E5.41 E0.2 <3 <0.61

Interstate 495 -P 422821071332001 09/29/2005 <1.26 E8.50 E0.7 <3 <0.61

Interstate 495 -P 422821071332001 10/22/2005 E1.39 E3.09 E0.1 <3 <0.61

Interstate 495 -P 422821071332001 10/24/2005 <1.26 E4.95 E0.07 <3 <0.61

Interstate 495 -P 422821071332001 01/11/2006 <1.26 E13.5 3 E0.3 <0.61

Interstate 495 -P 422821071332001 03/13/2006 <50.4 <42 E4 <140 <24.4

Interstate 495 -P 422821071332001 05/09/2006 <1.26 <2.61 E0.180 E0.0307 <0.61

Interstate 495 -P 422821071332001 06/02/2006 <1.26 <4.71 0.414 E0.0482 <0.61

Interstate 495 -P 422821071332001 08/20/2006 <1.26 E1.94 E0.105 <0.70 <0.61

Interstate 495 -P 422821071332001 08/27/2006 <1.26 E3.28 E0.0409 <0.70 <0.61

Interstate 495 -P 422821071332001 09/19/2006 <1.26 E2.97 E0.194 E0.0455 <0.61

Interstate 495 -P 422821071332001 11/12/2006 E0.436 E4.12 E0.222 E0.0398 1.52

Interstate 495 -P 422821071332001 01/08/2007 <1.26 E3.95 E0.231 E0.0434 <0.61

Interstate 495 -P 422821071332001 03/02/2007 E1.14 E17.1 E2.06 <0.70 <0.61

Interstate 495 -P 422821071332001 04/12/2007 E0.718 E9.88 1.23 E0.137 <0.61

Interstate 495 -P 422821071332001 08/06/2007 <1.26 E6.82 0.45 <0.70 <0.61

Interstate 495 -P 422821071332001 08/08/2007 <1.26 E5.20 0.434 <0.70 <0.61

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 <1.26 E9.30 E0.2 E0.06 <0.61

Interstate 495 -S 422716071343901 09/29/2005 <1.26 E5.80 E0.1 <3 <0.61

Interstate 495 -S 422716071343901 10/22/2005 <1.26 5.16 E0.1 <3 <0.61

Interstate 495 -S 422716071343901 10/24/2005 <1.26 E4.06 E0.06 <3 <0.61

Interstate 495 -S 422716071343901 01/11/2006 <1.26 E9.81 E1 <3 <0.61

Interstate 495 -S 422716071343901 01/18/2006 E1.53 E10.5 E1.0 <3 <0.61

Interstate 495 -S 422716071343901 03/13/2006 <25.2 <21 E0.8 <68 <12.2

Interstate 495 -S 422716071343901 05/09/2006 <1.26 <2.25 E0.0806 E0.0187 <0.61

Interstate 495 -S 422716071343901 06/02/2006 <1.26 <3.15 E0.121 <0.7 <0.61

Interstate 495 -S 422716071343901 08/20/2006 <1.26 2.06 E0.0594 <0.70 E0.235

Interstate 495 -S 422716071343901 09/19/2006 <1.26 E4.02 E0.0763 <0.70 <0.61
154 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Benzyl n-butyl 

phthalate,

total,

recoverable 

(μg/L)

Bis(2-ethylhexyl) 

phthalate,

total,

recoverable

(μg/L)

Chrysene,

total,

recoverable 

(μg/L)

Dibenzo[a,h]

anthracene, 

total,

recoverable 

(μg/L)

Diethyl

phthalate,

total,

recoverable

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 <1.26 E5.84 E0.4 E0.05 <0.61

Interstate 95 -P 422620071153301 09/29/2005 <1.26 E5.73 E0.4 <3 <0.61

Interstate 95 -P 422620071153301 10/22/2005 <1.26 <2.09 E0.06 <3 <0.61

Interstate 95 -P 422620071153301 11/16/2005 <1.26 E2.79 E0.1 <3 <0.61

Interstate 95 -P 422620071153301 01/12/2006 <1.26 E6.18 E2 E0.2 <0.61

Interstate 95 -P 422620071153301 01/18/2006 E1.81 E21.9 3 E0.4 <0.61

Interstate 95 -P 422620071153301 03/13/2006 <50.4 <52.1 E6 <140 <24.4

Interstate 95 -P 422620071153301 05/09/2006 <1.26 <3.46 0.802 E0.104 <0.61

Interstate 95 -P 422620071153301 06/02/2006 <1.26 <4.78 E0.256 E0.0347 <0.61

Interstate 95 -P 422620071153301 08/20/2006 <1.26 E0.898 E0.0459 <0.70 <0.61

Interstate 95 -P 422620071153301 08/27/2006 <1.26 E1.50 E0.0722 <0.70 <0.61

Interstate 95 -P 422620071153301 09/19/2006 <1.26 E3.66 E0.251 E0.0525 <0.61

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 <1.26 E5.87 E0.246 E0.0388 E0.315

Interstate 95 -P 422620071153301 03/11/2007 E0.504 E7.34 E0.814 <0.70 E0.468

Interstate 95 -P 422620071153301 03/17/2007 E0.750 E14.8 2.47 <0.70 <0.61

Interstate 95 -P 422620071153301 04/12/2007 E0.778 E14.0 1.5 E0.143 E0.209

Interstate 95 -P 422620071153301 08/06/2007 <1.26 E3.96 E0.197 <0.70 <0.61

Interstate 95 -P 422620071153301 08/08/2007 <1.26 E5.61 E0.304 <0.70 <0.61

Interstate 95 -S 422420071153302 08/20/2006 <1.26 1.83 E0.0957 <0.70 <0.61

Interstate 95 -S 422420071153302 08/27/2006 <1.26 E3.22 E0.0502 <0.70 <0.61

Interstate 95 -S 422420071153302 09/19/2006 E0.968 E3.73 E0.133 <0.70 <0.61

Interstate 95 -S 422420071153302 11/07/2006 E0.464 E4.95 E0.160 <0.70 E0.406

Interstate 95 -S 422420071153302 03/02/2007 E1.71 E24.2 E4.80 E0.274 <0.61

Interstate 95 -S 422420071153302 03/17/2007 E0.691 E11.9 2 <0.70 E0.330

Interstate 95 -S 422420071153302 04/12/2007 E0.722 E11.2 1.52 E0.163 E0.231

Interstate 95 -S 422420071153302 05/16/2007 <0.00 <17.0 1.13 <0.70 <0.61

Interstate 95 -S 422420071153302 08/06/2007 <1.26 E9.81 1.06 <0.70 <0.61

Interstate 95 -S 422420071153302 08/08/2007 <1.26 E8.12 0.462 <0.70 <0.61

Interstate 93 -T 421647071024703 04/23/2006 <1.24 E5.98 0.827 E0.0908 <0.61

Interstate 93 -T 421647071024703 06/23/2006 <1.26 E20.4 E1.91 E0.207 <0.61

Interstate 93 -T 421647071024703 09/19/2006 <1.26 E12.8 0.462 <0.70 <0.61

Interstate 93 -T 421647071024703 12/01/2006 E1.46 E14.3 1.23 <0.70 E0.357

Interstate 93 -T 421647071024703 02/14/2007 E3.76 E18.1 E2.22 <0.70 E0.491
Tables 16–21 155

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Dimethyl

phthalate,

total,

recoverable 

(μg/L)

Di-n-butyl 

phthalate,

total, 

recoverable 

(μg/L)

Di-n-octyl 

phthalate,

total,

recoverable, 

(μg/L)

Fluoranthene, 

total,

recoverable 

(μg/L)

Indeno[1,2,3-cd]-

pyrene,

total,

recoverable

(μg/L)

Route 119 -P 424209071545201 09/15/2005 <0.59 <0.87 E0.798 <2 <3

Route 119 -P 424209071545201 09/29/2005 <0.59 E0.792 <1.86 E0.1 E0.04

Route 119 -P 424209071545201 10/22/2005 -- -- -- -- --

Route 119 -P 424209071545201 10/24/2005 -- -- -- -- --

Route 119 -P 424209071545201 01/11/2006 <0.59 <0.87 E1.97 E1 E0.2

Route 119 -P 424209071545201 01/18/2006 <0.59 E0.443 E2.46 E0.7 E0.1

Route 119 -P 424209071545201 03/13/2006 <23.6 <34.8 <74.4 E0.9 E0.2

Route 119 -P 424209071545201 05/09/2006 <0.59 <0.87 <1.86 E0.0465 E0.0206

Route 119 -P 424209071545201 06/01/2006 <0.59 <0.87 <1.86 0.322 E0.122

Route 119 -P 424209071545201 09/14/2006 <0.59 <0.87 E0.911 E0.0844 <0.56

Route 119 -P 424209071545201 09/19/2006 E0.0590 <0.87 E0.405 E0.0418 <0.56

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 <0.59 E0.174 <1.86 E0.0389 <0.56

Route 119 -P 424209071545201 11/12/2006 <0.59 <0.87 E0.503 E0.0784 E0.0279

Route 119 -P 424209071545201 01/08/2007 <0.59 <0.87 E0.327 E0.131 E0.0361

Route 119 -P 424209071545201 04/01/2007 <0.59 <0.87 <1.86 E0.225 E0.0785

Route 119 -P 424209071545201 04/14/2007 <0.59 E0.192 E1.16 E0.263 E0.0527

Route 119 -P 424209071545201 06/03/2007 <0.59 <0.87 E0.357 <0.30 <0.56

Route 119 -P 424209071545201 07/11/2007 E0.0293 <0.87 E0.0860 E0.0616 E0.0243

Route 119 -S 424155071543201 09/29/2005 <0.59 E0.415 <1.86 E0.1 E0.05

Route 119 -S 424155071543201 10/24/2005 <0.59 E0.480 <1.86 E0.03 <3

Route 119 -S 424155071543201 01/11/2006 <0.59 <0.87 E1.93 E1 E0.2

Route 119 -S 424155071543201 01/18/2006 <0.59 E0.534 E1.74 E0.5 E0.09

Route 119 -S 424155071543201 03/13/2006 <23.6 <34.8 <74.4 E0.9 E0.3

Route 119 -S 424155071543201 08/20/2006 <0.59 <0.87 <1.86 E0.0317 <0.56

Route 119 -S 424155071543201 11/08/2006 <0.59 <0.87 <1.86 E0.0698 E0.0159

Route 119 -S 424155071543201 04/27/2007 <0.59 <0.87 <1.86 E0.178 E0.0393

Route 119 -S 424155071543201 06/03/2007 <0.59 <0.87 E0.162 <0.30 <0.56

Route 119 -S 424155071543201 07/11/2007 E0.0497 <0.87 E0.0739 E0.0488 E0.0224

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 E0.0359 <0.87 E0.827 E0.0782 E0.0290

Route 8 -T 424019073062601 06/23/2006 <0.59 <0.87 <1.86 E0.114 <0.56

Route 8 -T 424019073062601 09/23/2006 <0.59 <0.87 E1.16 E0.101 <0.56

Route 8 -T 424019073062601 12/01/2006 <0.59 E0.351 E1.87 0.385 E0.107

Route 8 -T 424019073062601 03/02/2007 <0.59 <0.87 E3.47 0.825 E0.167
156 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Dimethyl

phthalate,

total,

recoverable 

(μg/L)

Di-n-butyl 

phthalate,

total, 

recoverable 

(μg/L)

Di-n-octyl 

phthalate,

total,

recoverable, 

(μg/L)

Fluoranthene, 

total,

recoverable 

(μg/L)

Indeno[1,2,3-cd]-

pyrene,

total,

recoverable

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 <0.59 <0.87 E2.06 E0.5 E0.1

Interstate 190 -T 423016071431501 09/29/2005 <0.59 <0.87 E1.29 E0.3 E0.10

Interstate 190 -T 423016071431501 10/07/2005 <0.59 <0.87 E2.66 E0.09 E0.04

Interstate 190 -T 423016071431501 10/22/2005 -- -- -- -- --

Interstate 190 -T 423016071431501 10/24/2005 <0.59 E0.575 <1.86 E0.07 <3

Interstate 190 -T 423016071431501 03/13/2006 <11.8 <17.4 <37.2 E4 E0.7

Route 2 -P 423027071291301 09/15/2005 <0.59 <0.87 E1.85 E0.1 E0.06

Route 2 -P 423027071291301 09/29/2005 <0.59 E0.784 E1.44 E0.4 E0.1

Route 2 -P 423027071291301 10/22/2005 <0.59 E0.458 E1.14 E0.2 E0.05

Route 2 -P 423027071291301 10/24/2005 <0.59 E0.484 <1.86 E0.09 <3

Route 2 -P 423027071291301 01/11/2006 <0.59 E0.437 E3.08 E2 E0.3

Route 2 -P 423027071291301 01/18/2006 <0.59 E0.577 E6.92 E1 E0.2

Route 2 -P 423027071291301 03/13/2006 <0.59 <0.87 E1.39 E0.9 E0.2

Route 2 -P 423027071291301 05/09/2006 <0.59 <0.87 E1.81 E0.236 E0.0823

Route 2 -P 423027071291301 06/02/2006 <0.59 <0.87 <1.86 0.336 E0.153

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 <0.59 <0.87 E0.232 E0.209 E0.0622

Route 2 -P 423027071291301 08/27/2006 -- -- E0.547 E0.0315 --

Route 2 -P 423027071291301 09/19/2006 E0.0563 <0.87 E0.842 E0.255 E0.114

Route 2 -P 423027071291301 11/07/2006 <0.59 E0.294 E0.529 E0.0522 <0.56

Route 2 -P 423027071291301 01/08/2007 E0.0339 E0.300 E1.21 E0.262 E0.0888

Route 2 -P 423027071291301 03/02/2007 <0.59 <0.87 E7.64 2.45 E0.323

Route 2 -P 423027071291301 04/12/2007 <0.59 E0.348 E6.66 2.43 E0.464

Route 2 -P 423027071291301 08/06/2007 <0.59 <0.87 E1.76 0.421 E0.217

Route 2 -P 423027071291301 08/08/2007 <0.59 <0.87 E2.40 0.735 E0.176

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 <0.59 <0.87 E0.287 E0.0591 E0.0267

Route 2 -S 423027071291302 08/27/2006 E0.0314 <0.87 E0.912 E0.0708 E0.0215

Route 2 -S 423027071291302 09/19/2006 E0.0572 <0.87 E1.33 0.361 E0.142

Route 2 -S 423027071291302 12/01/2006 E0.0480 <0.87 E2.46 1.61 E0.326

Route 2 -S 423027071291302 01/08/2007 <0.59 E0.311 E1.12 E0.268 E0.0888

Route 2 -S 423027071291302 03/17/2007 <0.59 <0.87 2.33 1.39 E0.310

Route 2 -S 423027071291302 04/12/2007 <0.59 E0.338 E5.12 1.84 E0.366

Route 2 -S 423027071291302 05/16/2007 <0.59 E0.285 E3.19 0.642 E0.141

Route 2 -S 423027071291302 08/08/2007 E0.0592 <0.87 E1.34 0.525 E0.154
Tables 16–21 157

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Dimethyl

phthalate,

total,

recoverable 

(μg/L)

Di-n-butyl 

phthalate,

total, 

recoverable 

(μg/L)

Di-n-octyl 

phthalate,

total,

recoverable, 

(μg/L)

Fluoranthene, 

total,

recoverable 

(μg/L)

Indeno[1,2,3-cd]-

pyrene,

total,

recoverable

(μg/L)

Route 2 -S 423027071291302 08/06/2007 <0.59 <0.87 E1.67 0.741 E0.279

Interstate 195 -T 414339070462201 04/23/2006 E0.0337 <0.87 E1.95 E0.282 E0.0858

Interstate 195 -T 414339070462201 06/24/2006 <0.59 <0.87 <1.86 E0.157 E0.0690

Interstate 195 -T 414339070462201 09/29/2006 E0.0595 E0.882 E1.30 E0.148 E0.0519

Interstate 195 -T 414339070462201 12/01/2006 <0.59 <0.87 E1.70 0.489 E0.120

Interstate 195 -T 414339070462201 02/14/2007 E0.113 <0.87 E1.53 0.498 E0.113

Interstate 495 -P 422821071332001 09/15/2005 <0.59 <0.87 E1.30 E0.2 E0.07

Interstate 495 -P 422821071332001 09/29/2005 <0.59 E0.554 E1.97 E1 E0.3

Interstate 495 -P 422821071332001 10/22/2005 <0.59 E0.501 E0.841 E0.2 E0.05

Interstate 495 -P 422821071332001 10/24/2005 <0.59 E0.415 E0.901 E0.2 <3

Interstate 495 -P 422821071332001 01/11/2006 <0.59 E0.437 E3.88 6 E0.9

Interstate 495 -P 422821071332001 03/13/2006 <23.6 <34.8 <74.4 E7 E2

Interstate 495 -P 422821071332001 05/09/2006 <0.59 <0.87 <1.86 E0.293 E0.105

Interstate 495 -P 422821071332001 06/02/2006 <0.59 <0.87 <1.86 0.714 E0.239

Interstate 495 -P 422821071332001 08/20/2006 <0.59 <0.87 E0.423 E0.139 E0.0591

Interstate 495 -P 422821071332001 08/27/2006 <0.59 <0.87 E1.26 E0.0861 E0.0284

Interstate 495 -P 422821071332001 09/19/2006 E0.0754 <0.87 E1.11 0.434 E0.140

Interstate 495 -P 422821071332001 11/12/2006 <0.59 E0.312 <1.86 0.598 E0.139

Interstate 495 -P 422821071332001 01/08/2007 E0.0390 E0.386 E0.946 0.494 E0.144

Interstate 495 -P 422821071332001 03/02/2007 E0.179 <0.87 E2.74 E3.87 E0.482

Interstate 495 -P 422821071332001 04/12/2007 <0.59 <0.87 E3.40 2.33 E0.407

Interstate 495 -P 422821071332001 08/06/2007 <0.59 <0.87 E1.62 0.7 E0.313

Interstate 495 -P 422821071332001 08/08/2007 <0.59 <0.87 E1.37 0.717 E0.194

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 <0.59 <0.87 E2.13 E0.3 E0.1

Interstate 495 -S 422716071343901 09/29/2005 <0.59 E0.453 E1.61 E0.2 E0.06

Interstate 495 -S 422716071343901 10/22/2005 <0.59 E0.541 E1.41 E0.1 <3

Interstate 495 -S 422716071343901 10/24/2005 <0.59 E0.670 E1.20 E0.1 <3

Interstate 495 -S 422716071343901 01/11/2006 <0.59 E0.407 E3.40 E2 E0.3

Interstate 495 -S 422716071343901 01/18/2006 <0.59 E0.637 E4.34 E2 E0.3

Interstate 495 -S 422716071343901 03/13/2006 <11.8 <17.4 <37.2 E2 E0.5

Interstate 495 -S 422716071343901 05/09/2006 <0.59 <0.87 <1.86 E0.179 E0.0660

Interstate 495 -S 422716071343901 06/02/2006 E0.0403 <0.87 <1.86 E0.205 E0.0785

Interstate 495 -S 422716071343901 08/20/2006 <0.59 <0.87 E0.429 E0.122 E0.0512

Interstate 495 -S 422716071343901 09/19/2006 E0.0699 <0.87 E1.57 E0.158 E0.0711
158 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Dimethyl

phthalate,

total,

recoverable 

(μg/L)

Di-n-butyl 

phthalate,

total, 

recoverable 

(μg/L)

Di-n-octyl 

phthalate,

total,

recoverable, 

(μg/L)

Fluoranthene, 

total,

recoverable 

(μg/L)

Indeno[1,2,3-cd]-

pyrene,

total,

recoverable

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 <0.59 <0.87 E1.66 E0.5 E0.2

Interstate 95 -P 422620071153301 09/29/2005 <0.59 E0.464 E1.38 E0.7 E0.2

Interstate 95 -P 422620071153301 10/22/2005 <0.59 <0.87 E0.819 E0.1 <3

Interstate 95 -P 422620071153301 11/16/2005 <0.59 E0.451 <1.86 E0.2 E0.07

Interstate 95 -P 422620071153301 01/12/2006 <0.59 <0.87 E1.33 E2 E0.6

Interstate 95 -P 422620071153301 01/18/2006 <0.59 E0.750 E11.9 5 E1

Interstate 95 -P 422620071153301 03/13/2006 <23.6 <34.8 <74.4 E10 E3

Interstate 95 -P 422620071153301 05/09/2006 <0.59 <0.87 E2.81 1.15 E0.331

Interstate 95 -P 422620071153301 06/02/2006 <0.59 <0.87 <1.86 0.507 E0.197

Interstate 95 -P 422620071153301 08/20/2006 <0.59 E0.599 <1.86 E0.0877 E0.0312

Interstate 95 -P 422620071153301 08/27/2006 <0.59 <0.87 E0.511 E0.170 E0.0348

Interstate 95 -P 422620071153301 09/19/2006 E0.0554 <0.87 E1.55 0.41 E0.146

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 E0.106 <0.87 E1.95 0.554 E0.151

Interstate 95 -P 422620071153301 03/11/2007 <0.59 <0.87 E1.35 1.31 E0.422

Interstate 95 -P 422620071153301 03/17/2007 <0.59 E0.454 E3.32 3.68 E0.899

Interstate 95 -P 422620071153301 04/12/2007 E0.0675 E0.402 E5.01 2.42 E0.547

Interstate 95 -P 422620071153301 08/06/2007 <0.59 <0.87 E1.16 E0.237 E0.128

Interstate 95 -P 422620071153301 08/08/2007 <0.59 <0.87 E2.32 0.348 <0.56

Interstate 95 -S 422420071153302 08/20/2006 <0.59 <0.87 E0.359 E0.137 E0.0520

Interstate 95 -S 422420071153302 08/27/2006 E0.0372 <0.87 E1.32 E0.0994 E0.0281

Interstate 95 -S 422420071153302 09/19/2006 E0.0752 <0.87 E1.68 E0.253 E0.114

Interstate 95 -S 422420071153302 11/07/2006 E0.110 E0.364 E1.96 0.458 E0.0846

Interstate 95 -S 422420071153302 03/02/2007 <0.59 E1.60 E4.04 E9.95 E1.04

Interstate 95 -S 422420071153302 03/17/2007 <0.59 E0.467 E3.27 3.76 E0.762

Interstate 95 -S 422420071153302 04/12/2007 E0.0652 E0.442 E5.44 3.02 0.584

Interstate 95 -S 422420071153302 05/16/2007 <0.59 <0.426 E5.99 2.13 E0.425

Interstate 95 -S 422420071153302 08/06/2007 <0.59 <0.87 E3.24 1.6 E0.433

Interstate 95 -S 422420071153302 08/08/2007 <0.59 <0.87 E2.93 0.642 E0.211

Interstate 93 -T 421647071024703 04/23/2006 E0.131 E0.756 E5.19 1.41 E0.327

Interstate 93 -T 421647071024703 06/23/2006 E0.164 <0.87 E6.78 E2.96 E0.594

Interstate 93 -T 421647071024703 09/19/2006 <0.59 <0.87 E2.52 0.697 E0.230

Interstate 93 -T 421647071024703 12/01/2006 E0.123 E0.343 E5.33 1.96 E0.428

Interstate 93 -T 421647071024703 02/14/2007 <0.59 E2.01 <12.8 7 E1.08
Tables 16–21 159

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Nitrobenzene, 

total,

recoverable 

(μg/L)

Phenanthrene, 

total, 

recoverable 

(μg/L)

Pyrene,

total,

recoverable 

(μg/L)

Naphthalene, 

total,

recoverable 

(μg/L)

Perylene,

total,

recoverable 

(μg/L)

Route 119 -P 424209071545201 09/15/2005 <2 E0.02 <2 <2 <1

Route 119 -P 424209071545201 09/29/2005 <2 E0.06 E0.1 <2 <1

Route 119 -P 424209071545201 10/22/2005 -- -- -- -- --

Route 119 -P 424209071545201 10/24/2005 -- -- -- -- --

Route 119 -P 424209071545201 01/11/2006 <2 E0.7 E0.8 E0.05 E0.07

Route 119 -P 424209071545201 01/18/2006 <2 E0.4 E0.5 E0.03 <1

Route 119 -P 424209071545201 03/13/2006 <80 E0.6 E0.7 <72 <40

Route 119 -P 424209071545201 05/09/2006 <0.21 E0.0228 E0.0367 <0.32 <1

Route 119 -P 424209071545201 06/01/2006 <0.21 E0.158 E0.246 <0.32 E0.04

Route 119 -P 424209071545201 09/14/2006 <0.21 <0.32 E0.0778 <0.32 <1

Route 119 -P 424209071545201 09/19/2006 <0.21 E0.0198 E0.0364 <0.32 <1

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 <0.21 E0.0198 E0.0273 <0.32 <1

Route 119 -P 424209071545201 11/12/2006 <0.21 E0.0368 E0.0702 <0.32 <1

Route 119 -P 424209071545201 01/08/2007 <0.21 E0.0614 E0.101 <0.32 E0.01

Route 119 -P 424209071545201 04/01/2007 <0.21 E0.116 E0.151 <0.32 <1

Route 119 -P 424209071545201 04/14/2007 <0.21 E0.146 E0.181 <0.32 <1

Route 119 -P 424209071545201 06/03/2007 <0.21 <0.32 <0.35 <0.32 <1

Route 119 -P 424209071545201 07/11/2007 <0.21 E0.0317 E0.0460 <0.32 <1

Route 119 -S 424155071543201 09/29/2005 <2 E0.06 E0.1 <2 <1

Route 119 -S 424155071543201 10/24/2005 <2 E0.03 E0.03 <2 <1

Route 119 -S 424155071543201 01/11/2006 <2 E0.6 E0.9 E0.04 <1

Route 119 -S 424155071543201 01/18/2006 <2 E0.3 E0.4 E0.03 <1

Route 119 -S 424155071543201 03/13/2006 <80 E0.5 E0.6 <72 <40

Route 119 -S 424155071543201 08/20/2006 E0.0287 E0.0163 E0.0277 <0.32 <1

Route 119 -S 424155071543201 11/08/2006 <0.21 E0.0303 E0.0556 E0.0345 <1

Route 119 -S 424155071543201 04/27/2007 <0.21 E0.0921 E0.126 <0.32 <1

Route 119 -S 424155071543201 06/03/2007 <0.21 <0.32 <0.35 <0.32 <1

Route 119 -S 424155071543201 07/11/2007 <0.21 <0.32 E0.0455 <0.32 <1

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 <0.21 E0.0363 E0.0676 E0.0186 <1

Route 8 -T 424019073062601 06/23/2006 <0.21 E0.0549 E0.101 <0.32 E0.03

Route 8 -T 424019073062601 09/23/2006 <0.21 E0.0406 E0.0984 <0.32 <1

Route 8 -T 424019073062601 12/01/2006 <0.21 E0.155 0.355 E0.0290 E0.04

Route 8 -T 424019073062601 03/02/2007 <0.21 0.602 0.606 <0.32 <1
160 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Nitrobenzene, 

total,

recoverable 

(μg/L)

Phenanthrene, 

total, 

recoverable 

(μg/L)

Pyrene,

total,

recoverable 

(μg/L)

Naphthalene, 

total,

recoverable 

(μg/L)

Perylene,

total,

recoverable 

(μg/L)

Interstate 190 -T 423016071431501 08/14/2005 <2 <2 E0.4 <2 E0.05

Interstate 190 -T 423016071431501 09/29/2005 <2 E0.1 E0.3 E0.02 E0.03

Interstate 190 -T 423016071431501 10/07/2005 <2 E0.03 E0.08 <2 <1

Interstate 190 -T 423016071431501 10/22/2005 -- -- -- -- --

Interstate 190 -T 423016071431501 10/24/2005 <2 E0.04 E0.06 <2 <1

Interstate 190 -T 423016071431501 03/13/2006 <40 E2 E3 <36 E0.3

Route 2 -P 423027071291301 09/15/2005 <2 <2 E0.1 <2 <1

Route 2 -P 423027071291301 09/29/2005 <2 E0.2 E0.4 E0.06 E0.06

Route 2 -P 423027071291301 10/22/2005 <2 E0.07 E0.1 <2 <1

Route 2 -P 423027071291301 10/24/2005 <2 E0.05 E0.08 <2 <1

Route 2 -P 423027071291301 01/11/2006 <2 E1 E1 E0.09 E0.1

Route 2 -P 423027071291301 01/18/2006 <2 E0.8 E1 E0.04 E0.1

Route 2 -P 423027071291301 03/13/2006 E0.02 E0.5 E0.6 E0.04 E0.07

Route 2 -P 423027071291301 05/09/2006 <0.21 E0.0934 E0.169 E0.0349 E0.02

Route 2 -P 423027071291301 06/02/2006 <0.21 E0.134 E0.262 <0.32 E0.04

Route 2 -P 423027071291301 06/23/2006 -- -- -- -- --

Route 2 -P 423027071291301 08/20/2006 <0.21 E0.0896 E0.166 <0.32 E0.02

Route 2 -P 423027071291301 08/27/2006 -- E0.0141 E0.0242 -- --

Route 2 -P 423027071291301 09/19/2006 <0.21 E0.101 E0.207 <0.32 E0.03

Route 2 -P 423027071291301 11/07/2006 E0.0585 E0.0305 E0.0509 E0.0231 <1

Route 2 -P 423027071291301 01/08/2007 <0.21 E0.121 E0.215 <0.32 E0.02

Route 2 -P 423027071291301 03/02/2007 <0.21 1.6 1.71 E0.112 E0.1

Route 2 -P 423027071291301 04/12/2007 <0.21 1.22 1.75 E0.0721 E0.2

Route 2 -P 423027071291301 08/06/2007 <0.21 E0.184 E0.372 <0.32 <1

Route 2 -P 423027071291301 08/08/2007 <0.21 E0.274 E0.547 <0.32 <1

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 <0.21 E0.0235 E0.0480 <0.32 <1

Route 2 -S 423027071291302 08/27/2006 <0.21 E0.0295 E0.0495 <0.32 <1

Route 2 -S 423027071291302 09/19/2006 <0.21 E0.138 E0.277 <0.32 E0.03

Route 2 -S 423027071291302 12/01/2006 <0.21 0.787 1.21 E0.0369 E0.1

Route 2 -S 423027071291302 01/08/2007 <0.21 E0.127 E0.203 <0.32 E0.02

Route 2 -S 423027071291302 03/17/2007 <0.21 0.848 0.945 E0.0444 <1

Route 2 -S 423027071291302 04/12/2007 <0.21 0.964 1.2 E0.0475 E0.1

Route 2 -S 423027071291302 05/16/2007 <0.21 E0.296 0.468 E0.0396 E0.06

Route 2 -S 423027071291302 08/08/2007 <0.21 E0.228 E0.417 <0.32 E0.1
Tables 16–21 161

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Nitrobenzene, 

total,

recoverable 

(μg/L)

Phenanthrene, 

total, 

recoverable 

(μg/L)

Pyrene,

total,

recoverable 

(μg/L)

Naphthalene, 

total,

recoverable 

(μg/L)

Perylene,

total,

recoverable 

(μg/L)

Route 2 -S 423027071291302 08/06/2007 <0.21 0.329 E0.598 <0.32 E0.1

Interstate 195 -T 414339070462201 04/23/2006 <0.21 E0.107 E0.203 E0.0191 E0.02

Interstate 195 -T 414339070462201 06/24/2006 <0.21 E0.0546 E0.135 <0.32 E0.03

Interstate 195 -T 414339070462201 09/29/2006 <0.21 E0.0702 E0.114 <0.32 E0.02

Interstate 195 -T 414339070462201 12/01/2006 <0.21 0.341 0.394 E0.0454 E0.06

Interstate 195 -T 414339070462201 02/14/2007 <0.21 E0.230 0.402 <0.32 <1

Interstate 495 -P 422821071332001 09/15/2005 <2 E0.09 E0.2 <2 <1

Interstate 495 -P 422821071332001 09/29/2005 <2 E0.5 E1.0 E0.05 E0.1

Interstate 495 -P 422821071332001 10/22/2005 <2 E0.1 E0.2 <2 <1

Interstate 495 -P 422821071332001 10/24/2005 <2 E0.08 E0.2 <2 <1

Interstate 495 -P 422821071332001 01/11/2006 <2 5 E4 E0.4 E0.5

Interstate 495 -P 422821071332001 03/13/2006 <80 E4 E5 <72 E0.6

Interstate 495 -P 422821071332001 05/09/2006 E0.0277 E0.124 E0.216 E0.0220 E0.04

Interstate 495 -P 422821071332001 06/02/2006 <0.21 E0.292 0.596 <0.32 E0.09

Interstate 495 -P 422821071332001 08/20/2006 <0.21 E0.0458 E0.129 <0.32 E0.03

Interstate 495 -P 422821071332001 08/27/2006 <0.21 E0.0297 E0.0724 <0.32 <1

Interstate 495 -P 422821071332001 09/19/2006 <0.21 E0.158 0.373 <0.32 E0.05

Interstate 495 -P 422821071332001 11/12/2006 <0.21 E0.246 0.478 E0.0581 E0.05

Interstate 495 -P 422821071332001 01/08/2007 <0.21 E0.280 0.396 <0.32 E0.05

Interstate 495 -P 422821071332001 03/02/2007 <0.21 E3.14 E2.68 E0.349 E0.2

Interstate 495 -P 422821071332001 04/12/2007 <0.21 1.33 1.68 E0.0841 E0.2

Interstate 495 -P 422821071332001 08/06/2007 <0.21 E0.309 E0.586 <0.32 E0.1

Interstate 495 -P 422821071332001 08/08/2007 <0.21 0.431 E0.591 <0.32 E0.1

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 <2 E0.09 E0.3 E0.02 <1

Interstate 495 -S 422716071343901 09/29/2005 <2 E0.08 E0.2 <2 <1

Interstate 495 -S 422716071343901 10/22/2005 <2 E0.07 E0.1 <2 <1

Interstate 495 -S 422716071343901 10/24/2005 <2 E0.06 E0.10 <2 <1

Interstate 495 -S 422716071343901 01/11/2006 <2 E1 E2 E0.09 E0.2

Interstate 495 -S 422716071343901 01/18/2006 <2 E0.9 E1 E0.06 E0.1

Interstate 495 -S 422716071343901 03/13/2006 <40 E0.8 E1 <36 E0.1

Interstate 495 -S 422716071343901 05/09/2006 E0.0529 E0.0850 E0.140 E0.0266 <1

Interstate 495 -S 422716071343901 06/02/2006 <0.21 E0.0796 E0.168 E0.0237 E0.02

Interstate 495 -S 422716071343901 08/20/2006 E0.0442 E0.0462 E0.108 <0.32 <1

Interstate 495 -S 422716071343901 09/19/2006 E0.0564 E0.0548 E0.151 <0.32 E0.02
162 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

Nitrobenzene, 

total,

recoverable 

(μg/L)

Phenanthrene, 

total, 

recoverable 

(μg/L)

Pyrene,

total,

recoverable 

(μg/L)

Naphthalene, 

total,

recoverable 

(μg/L)

Perylene,

total,

recoverable 

(μg/L)

Interstate 95 -P 422620071153301 09/15/2005 <2 E0.2 E0.4 E0.03 E0.05

Interstate 95 -P 422620071153301 09/29/2005 <2 E0.3 E0.6 E0.03 E0.07

Interstate 95 -P 422620071153301 10/22/2005 <2 E0.04 E0.09 <2 <1

Interstate 95 -P 422620071153301 11/16/2005 <2 E0.06 E0.2 E0.02 <1

Interstate 95 -P 422620071153301 01/12/2006 <2 E1 E2 E0.08 E0.2

Interstate 95 -P 422620071153301 01/18/2006 <2 2 E3 E0.08 E0.5

Interstate 95 -P 422620071153301 03/13/2006 <80 E4 E8 <72 E0.8

Interstate 95 -P 422620071153301 05/09/2006 <0.21 0.442 0.858 E0.0467 E0.1

Interstate 95 -P 422620071153301 06/02/2006 <0.21 E0.138 0.422 <0.32 E0.05

Interstate 95 -P 422620071153301 08/20/2006 <0.21 E0.0230 E0.0769 <0.32

Interstate 95 -P 422620071153301 08/27/2006 <0.21 E0.0823 E0.119 <0.32 E0.02

Interstate 95 -P 422620071153301 09/19/2006 <0.21 E0.138 E0.333 <0.32 E0.04

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 <0.21 E0.182 0.485 E0.0281 E0.05

Interstate 95 -P 422620071153301 03/11/2007 <0.21 0.645 0.945 E0.0853 <1

Interstate 95 -P 422620071153301 03/17/2007 <0.21 1.83 2.79 E0.132 E0.4

Interstate 95 -P 422620071153301 04/12/2007 <0.21 1.03 1.77 E0.0860

Interstate 95 -P 422620071153301 08/06/2007 <0.21 <0.32 E0.198 <0.32 <1

Interstate 95 -P 422620071153301 08/08/2007 <0.21 E0.136 E0.283 <0.32 <1

Interstate 95 -S 422420071153302 08/20/2006 <0.21 E0.0528 E0.111 <0.32 E0.02

Interstate 95 -S 422420071153302 08/27/2006 <0.21 E0.0402 E0.0812 <0.32 <1

Interstate 95 -S 422420071153302 09/19/2006 <0.21 E0.0966 E0.220 <0.32 E0.03

Interstate 95 -S 422420071153302 11/07/2006 <0.21 E0.258 0.408 E0.0533 E0.03

Interstate 95 -S 422420071153302 03/02/2007 <0.21 5.82 6.07 E0.152 E0.4

Interstate 95 -S 422420071153302 03/17/2007 <0.21 2.75 2.68 E0.226 E0.4

Interstate 95 -S 422420071153302 04/12/2007 <0.21 1.77 2.14 E0.0913 E0.3

Interstate 95 -S 422420071153302 05/16/2007 <0.21 1.12 1.55 E0.0672 E0.2

Interstate 95 -S 422420071153302 08/06/2007 <0.21 0.62 E1.24 <0.32 E0.3

Interstate 95 -S 422420071153302 08/08/2007 <0.21 E0.252 E0.513 <0.32 <1

Interstate 93 -T 421647071024703 04/23/2006 <0.21 0.529 1.08 E0.0596 E0.1

Interstate 93 -T 421647071024703 06/23/2006 <0.21 E1.40 E2.22 E0.0573 E0.4

Interstate 93 -T 421647071024703 09/19/2006 <0.21 E0.234 0.603 <0.32 --

Interstate 93 -T 421647071024703 12/01/2006 <0.21 0.914 1.59 E0.0743 E0.2

Interstate 93 -T 421647071024703 02/14/2007 <0.21 3 6 E0.273 <1
Tables 16–21 163

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

2-Fluorobiphenyl,

surrogate

(percent

recovery)

p-Terphenyl-d14

(percent

recovery)

Suspended 

sediment

(percent

< 0.063 mm)

Suspended 

sediment

(percent

< 0.25 mm)

Suspended

sediment

concentration 

(mg/L)

Route 119 -P 424209071545201 09/15/2005 93.9 41.2 84 89 17

Route 119 -P 424209071545201 09/29/2005 97.7 E111 61 86 38

Route 119 -P 424209071545201 10/22/2005 -- -- 75 85 6

Route 119 -P 424209071545201 10/24/2005 -- -- 83 90 3

Route 119 -P 424209071545201 01/11/2006 64.3 48.7 89 97 263

Route 119 -P 424209071545201 01/18/2006 76.4 85.8 63 80 278

Route 119 -P 424209071545201 03/13/2006 20.7 18.3 68 83 879

Route 119 -P 424209071545201 05/09/2006 59.5 41.3 82 91 12

Route 119 -P 424209071545201 06/01/2006 55.8 43.6 90 99 157

Route 119 -P 424209071545201 09/14/2006 93.8 92.5 94 97 8

Route 119 -P 424209071545201 09/19/2006 72.8 58.8 90 95 5

Route 119 -P 424209071545201 10/20/2006 -- -- -- -- --

Route 119 -P 424209071545201 11/08/2006 75.9 82.4 80 88 3

Route 119 -P 424209071545201 11/12/2006 79.6 95.3 69 87 12

Route 119 -P 424209071545201 01/08/2007 52.1 38.0 91 98 18

Route 119 -P 424209071545201 04/01/2007 85.2 42.9 80 88 33

Route 119 -P 424209071545201 04/14/2007 83.5 68.0 94 98 76

Route 119 -P 424209071545201 06/03/2007 59.2 32.3 94 97 7

Route 119 -P 424209071545201 07/11/2007 71.7 45.9 56 82 22

Route 119 -S 424155071543201 09/29/2005 97.3 E91.6 44 77 57

Route 119 -S 424155071543201 10/24/2005 97.5 112.0 67 97 4

Route 119 -S 424155071543201 01/11/2006 71.8 62.2 64 95 263

Route 119 -S 424155071543201 01/18/2006 78.4 107.0 79 94 160

Route 119 -S 424155071543201 03/13/2006 63.8 49.6 85 98 439

Route 119 -S 424155071543201 08/20/2006 89.1 73.1 52 66 17

Route 119 -S 424155071543201 11/08/2006 79.9 80.1 28 44 19

Route 119 -S 424155071543201 04/27/2007 67.6 65.9 59 82 95

Route 119 -S 424155071543201 06/03/2007 69.2 47.0 54 87 30

Route 119 -S 424155071543201 07/11/2007 71.6 76.0 64 93 18

Route 119 -S 424155071543201 08/03/2007 -- -- -- -- --

Route 8 -T 424019073062601 04/22/2006 60.0 43.1 96 -- 13

Route 8 -T 424019073062601 06/23/2006 65.0 31.8 27 44 107

Route 8 -T 424019073062601 09/23/2006 70.7 38.2 91 94 20

Route 8 -T 424019073062601 12/01/2006 74.4 55.6 25 34 400

Route 8 -T 424019073062601 03/02/2007 55.0 E56.6 99 100 242
164 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

2-Fluorobiphenyl,

surrogate

(percent

recovery)

p-Terphenyl-d14

(percent

recovery)

Suspended 

sediment

(percent

< 0.063 mm)

Suspended 

sediment

(percent

< 0.25 mm)

Suspended

sediment

concentration 

(mg/L)

Interstate 190 -T 423016071431501 08/14/2005 94.6 56.7 59 88 86

Interstate 190 -T 423016071431501 09/29/2005 92.9 E73.5 56 88 112

Interstate 190 -T 423016071431501 10/07/2005 94.8 55.6 74 94 17

Interstate 190 -T 423016071431501 10/22/2005 -- -- 63 78 11

Interstate 190 -T 423016071431501 10/24/2005 102.4 88.8 87 97 8

Interstate 190 -T 423016071431501 03/13/2006 41.3 31.7 86 96 528

Route 2 -P 423027071291301 09/15/2005 88.6 51.1 50 56 57

Route 2 -P 423027071291301 09/29/2005 88.5 E52.1 46 68 121

Route 2 -P 423027071291301 10/22/2005 94.9 77.4 31 66 51

Route 2 -P 423027071291301 10/24/2005 107.9 128.0 37 60 13

Route 2 -P 423027071291301 01/11/2006 62.8 39.1 98 99 266

Route 2 -P 423027071291301 01/18/2006 69.9 80.5 97 99 153

Route 2 -P 423027071291301 03/13/2006 14.5 9.3 87 94 327

Route 2 -P 423027071291301 05/09/2006 62.3 29.5 -- -- --

Route 2 -P 423027071291301 06/02/2006 57.7 40.2 -- -- --

Route 2 -P 423027071291301 06/23/2006 -- -- 35 69 124

Route 2 -P 423027071291301 08/20/2006 63.2 55.6 29 57 49

Route 2 -P 423027071291301 08/27/2006 17.1 19.6 59 79 6

Route 2 -P 423027071291301 09/19/2006 79.7 59.1 34 59 56

Route 2 -P 423027071291301 11/07/2006 76.5 38.8 47 71 6

Route 2 -P 423027071291301 01/08/2007 57.9 29.1 60 73 39

Route 2 -P 423027071291301 03/02/2007 59.7 E60.7 77 84 406

Route 2 -P 423027071291301 04/12/2007 84.9 63.8 84 94 336

Route 2 -P 423027071291301 08/06/2007 74.4 51.2 18 66 114

Route 2 -P 423027071291301 08/08/2007 73.9 69.9 57 90 94

Route 2 -P 423027071291301 09/10/2007 -- -- -- -- --

Route 2 -S 423027071291302 08/20/2006 60.2 43.9 54 77 19

Route 2 -S 423027071291302 08/27/2006 60.0 48.0 42 61 14

Route 2 -S 423027071291302 09/19/2006 74.1 51.1 11 28 198

Route 2 -S 423027071291302 12/01/2006 71.1 63.1 25 63 268

Route 2 -S 423027071291302 01/08/2007 53.6 34.6 74 83 26

Route 2 -S 423027071291302 03/17/2007 86.1 50.5 85 92 80

Route 2 -S 423027071291302 04/12/2007 86.3 55.4 63 71 187

Route 2 -S 423027071291302 05/16/2007 84.2 93.3 66 91 87

Route 2 -S 423027071291302 08/08/2007 68.9 72.3 33 58 157
Tables 16–21 165

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

2-Fluorobiphenyl,

surrogate

(percent

recovery)

p-Terphenyl-d14

(percent

recovery)

Suspended 

sediment

(percent

< 0.063 mm)

Suspended 

sediment

(percent

< 0.25 mm)

Suspended

sediment

concentration 

(mg/L)

Route 2 -S 423027071291302 08/06/2007 69.3 45.4 47 75 145

Interstate 195 -T 414339070462201 04/23/2006 79.3 64.8 86 91 37

Interstate 195 -T 414339070462201 06/24/2006 69.7 61.5 52 80 39

Interstate 195 -T 414339070462201 09/29/2006 69.2 75.7 59 77 28

Interstate 195 -T 414339070462201 12/01/2006 71.2 77.8 70 90 31

Interstate 195 -T 414339070462201 02/14/2007 59.8 50.1 63 70 48

Interstate 495 -P 422821071332001 09/15/2005 82.9 41.2 74 82 41

Interstate 495 -P 422821071332001 09/29/2005 96.8 E79.2 13 25 572

Interstate 495 -P 422821071332001 10/22/2005 98.9 79.2 45 71 33

Interstate 495 -P 422821071332001 10/24/2005 98.7 87.9 29 40 38

Interstate 495 -P 422821071332001 01/11/2006 43.6 39.4 58 66 958

Interstate 495 -P 422821071332001 03/13/2006 63.0 67.9 48 62 877

Interstate 495 -P 422821071332001 05/09/2006 40.7 21.4 91 97 28

Interstate 495 -P 422821071332001 06/02/2006 74.2 53.4 18 39 284

Interstate 495 -P 422821071332001 08/20/2006 60.5 46.5 28 65 59

Interstate 495 -P 422821071332001 08/27/2006 58.7 43.1 65 86 12

Interstate 495 -P 422821071332001 09/19/2006 74.0 60.3 46 76 52

Interstate 495 -P 422821071332001 11/12/2006 78.2 76.4 51 81 66

Interstate 495 -P 422821071332001 01/08/2007 58.3 40.2 81 89 25

Interstate 495 -P 422821071332001 03/02/2007 44.4 E38.8 95 98 2,060

Interstate 495 -P 422821071332001 04/12/2007 60.7 35.1 72 89 347

Interstate 495 -P 422821071332001 08/06/2007 66.0 52.1 48 84 136

Interstate 495 -P 422821071332001 08/08/2007 54.2 48.2 51 86 134

Interstate 495 -P 422821071332001 09/10/2007 -- -- -- -- --

Interstate 495 -S 422716071343901 09/15/2005 93.7 58.2 89 92 41

Interstate 495 -S 422716071343901 09/29/2005 75.9 E55.1 88 98 33

Interstate 495 -S 422716071343901 10/22/2005 101.0 89.6 85 93 11

Interstate 495 -S 422716071343901 10/24/2005 98.3 109.0 79 93 8

Interstate 495 -S 422716071343901 01/11/2006 51.4 42.1 98 99 351

Interstate 495 -S 422716071343901 01/18/2006 77.0 93.3 98 99 173

Interstate 495 -S 422716071343901 03/13/2006 41.2 38.5 98 99 242

Interstate 495 -S 422716071343901 05/09/2006 62.7 28.8 79 94 22

Interstate 495 -S 422716071343901 06/02/2006 68.4 53.8 85 96 23

Interstate 495 -S 422716071343901 08/20/2006 62.4 46.0 82 99 19

Interstate 495 -S 422716071343901 09/19/2006 77.2 75.9 81 88 16
166 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 16. Physical properties and concentrations of dissolved major ions, total nutrients, total-recoverable metals, polyaromatic 

hydrocarbons, phthalate esters, and suspended sediment in stormwater composite samples of highway runoff collected from 12 

stations on 8 highways in Massachusetts, 2005–07.—Continued

[USGS, U.S. Geological Survey; -P, primary monitoring station; -S, secondary monitoring station; -T, monitoring station on test highway; mm/dd/yyyy, month, 

day, year; hrmn, hour minute; NTRU, nephelometric turbidity ratio units; mg/L, milligrams per liter; μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mm, millimeter; <, concentration is less than the laboratory reporting limit; --, no data; E, the recovery or variation in recovery 

of the analyte was outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; blue-shaded 

values are associated with the secondary monitoring sites for each principal highway; gray-shaded values are associated with the monitoring sites for each test 

highway]

Highway and 

designation

USGS

station number

Begin date 

(mm/dd/yyyy)

2-Fluorobiphenyl,

surrogate

(percent

recovery)

p-Terphenyl-d14

(percent

recovery)

Suspended 

sediment

(percent

< 0.063 mm)

Suspended 

sediment

(percent

< 0.25 mm)

Suspended

sediment

concentration 

(mg/L)

Interstate 95 -P 422620071153301 09/15/2005 77.9 25.0 36 63 87

Interstate 95 -P 422620071153301 09/29/2005 93.5 E78.9 9 15 254

Interstate 95 -P 422620071153301 10/22/2005 65.0 46.1 53 86 11

Interstate 95 -P 422620071153301 11/16/2005 99.2 62.6 60 73 19

Interstate 95 -P 422620071153301 01/12/2006 29.4 20.9 97 98 387

Interstate 95 -P 422620071153301 01/18/2006 75.6 104.0 16 18 1,360

Interstate 95 -P 422620071153301 03/13/2006 52.4 55.4 79 79 655

Interstate 95 -P 422620071153301 05/09/2006 61.9 37.2 70 77 88

Interstate 95 -P 422620071153301 06/02/2006 44.1 22.2 39 46 78

Interstate 95 -P 422620071153301 08/20/2006 53.6 19.8 32 46 26

Interstate 95 -P 422620071153301 08/27/2006 24.5 27.5 56 71 12

Interstate 95 -P 422620071153301 09/19/2006 80.8 64.2 18 36 91

Interstate 95 -P 422620071153301 10/20/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 10/28/2006 -- -- -- -- --

Interstate 95 -P 422620071153301 11/07/2006 84.7 57.1 51 63 66

Interstate 95 -P 422620071153301 03/11/2007 53.1 E34.2 85 88 112

Interstate 95 -P 422620071153301 03/17/2007 77.2 45.1 74 84 406

Interstate 95 -P 422620071153301 04/12/2007 69.1 39.0 88 93 174

Interstate 95 -P 422620071153301 08/06/2007 61.4 40.3 51 85 58

Interstate 95 -P 422620071153301 08/08/2007 69.5 49.1 88 95 35

Interstate 95 -S 422420071153302 08/20/2006 64.0 30.3 56 82 20

Interstate 95 -S 422420071153302 08/27/2006 50.5 19.7 82 95 12

Interstate 95 -S 422420071153302 09/19/2006 68.5 35.9 65 86 22

Interstate 95 -S 422420071153302 11/07/2006 86.1 55.0 84 95 16

Interstate 95 -S 422420071153302 03/02/2007 66.2 E75.5 95 99 347

Interstate 95 -S 422420071153302 03/17/2007 89.6 67.5 87 94 255

Interstate 95 -S 422420071153302 04/12/2007 71.0 32.9 77 88 169

Interstate 95 -S 422420071153302 05/16/2007 85.3 97.1 49 75 248

Interstate 95 -S 422420071153302 08/06/2007 60.0 55.9 54 86 188

Interstate 95 -S 422420071153302 08/08/2007 58.4 47.4 70 83 74

Interstate 93 -T 421647071024703 04/23/2006 72.4 27.5 96 99 90

Interstate 93 -T 421647071024703 06/23/2006 23.7 18.6 4 13 4,050

Interstate 93 -T 421647071024703 09/19/2006 83.3 46.1 17 32 207

Interstate 93 -T 421647071024703 12/01/2006 74.1 45.5 21 39 714

Interstate 93 -T 421647071024703 02/14/2007 60.9 56.4 62 81 718
Tables 16–21

167

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway USGS station number Begin date (mm/dd/yyyy) Begin time (hrmn) End date (mm/dd/yyyy) End time (hrmn) Total precipitation (inches) Total storm volume (cubic feet) Runoff coefficient (percent)

Antecedant

dry period

between

periods of flow

(days)

Interstate 93 421647071024703 9/19/2006 2236 9/20/2006 0321 0.61 2,600 79 5.1

Interstate 93 421647071024703 12/1/2006 1635 12/1/2006 2217 0.26 829 59 3.1

Interstate 93 421647071024703 2/14/2007 1109 2/14/2007 1436 1.72 8,690 94 11.4Interstate 95 422620071153301 8/20/2006 0430 8/20/2006 0652 0.49 2,590 97 4.6

Interstate 95 422620071153301 3/11/2007 0321 3/11/2007 0508 0.23 195 32 8.5

Interstate 95 422620071153301 4/12/2007 1404 4/12/2007 1726 1.06 1,060 38 7.4

Interstate 495 422821071332001 8/20/2006 0315 8/20/2006 0940 1.36 3,660 195 4.7

Interstate 495 422821071332001 1/8/2007 0457 1/8/2007 1450 0.88 1,470 121 1.8

Interstate 495 422821071332001 4/12/2007 1234 4/12/2007 1857 1.06 1,060 72 6.9

Route 2 423027071291301 8/27/2006 1451 8/28/2006 0413 0.84 512 64 1.9

Route 2 423027071291301 1/8/2007 0456 1/8/2007 1645 0.88 1,170 140 2.2

Route 2 423027071291301 9/10/2007 2309 9/11/2007 0107 0.31 346 117 23.9

Route 119 424209071545201 9/14/2006 1519 9/14/2006 2035 0.35 1,660 219 8.8

Route 119 424209071545201 1/8/2007 0100 1/8/2007 1432 1.02 2,660 120 1.1

Route 119 424209071545201 4/14/2007 1332 4/16/2007 0134 2.03 3,590 82 2.8
168 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued [USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute] Highway Storm duration (hours) Turbidity (NTRU) pH, field (standard units) Specific conductance

(μS/cm)

1-Methylnaphthalene

(μg/L)

2,6-Dimethylnaphthalene

(μg/L)

2-Methylnaphthalene

(μg/L)

3,4-Dichlorophenyl

isocyanate

(μg/L)

Interstate 93 5 28 6.8 108 E0.0129 E0.0089 E0.0164 <0.2

Interstate 93 6 96 6.9 183 E0.0246 <0.2 E0.0381 <2

Interstate 93 8 540 7.1 13,200 E0.118 E0.117 E0.197 <2

Interstate 95 7 6.4 6.6 98 <0.2 <0.2 <0.2 <2

Interstate 95 2 180 7 13,400 E0.0148 E0.0270 E0.0311 <2

Interstate 95 4 150 6.8 3,640 E0.0308 <0.2 E0.0549 <2

Interstate 495 7.0 9.3 6.6 59 <0.2 <0.2 <0.2 <2

Interstate 495 10.0 28 6.7 190 E0.0103 <0.2 E0.0161 E0.0583

Interstate 495 8.0 200 7 9,600 E0.0314 <0.2 E0.0490 <2

Route 2 6.8 4.8 6.6 69 <0.2 <0.2 <0.2Route 2 9.8 27 6.6 152 E0.0082 <0.2 E0.0150 E0.0268

Route 2 1.1 18 6.8 123 E0.0204 <0.2 E0.0238 <2

Route 119 5.9 12 6.3 73 <0.2 <0.2 E0.0051 <2

Route 119 14.9 17 6.2 103 <0.2 E0.0053 E0.0097 <2

Route 119 77.7 65 7.2 9,160 <0.2 <0.2 <0.2 <2
Tables 16–21

169

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway

3betaCoprostanol

(μg/L)

3-Methyl1H-indole

(μg/L)

3-tert-Butyl-4-

hydroxyanisole

(μg/L)

4-Cumylphenol

(μg/L)

4-n-Octylphenol

(μg/L)

4-Nonylphenol

(μg/L)

4-tert-Octylphenol

(μg/L)

Interstate 93 <3.20 <0.2 <0.2 <0.2 <0.2 E0.573 E0.193

Interstate 93 E1.52 E0.0483 <0.2 <0.2 <0.2 E1.36 0.374

Interstate 93 <0.8 <0.2 <0.2 <0.2 <0.2 <4.33 E0.626Interstate 95 <0.8 <0.2 <0.2 <0.2 <0.2 <1.6 <0.2

Interstate 95 <0.8 <0.2 <0.2 <0.2 E0.576 <0.2

Interstate 95 <0.8 <0.2 <0.2 <0.2 E1.35 0.351

Interstate 495 E0.435 <0.2 <0.2 <0.2 <0.2 <1.6 <0.2Interstate 495 E0.574 <0.2 <0.2 <0.2 <0.2 <1.6 E0.154

Interstate 495 <0.8 <0.2 <0.2 <0.2 <1.6 E0.209Route 2 <0.8 <0.2 <0.2 <0.2 <0.2 <1.6 E0.0959Route 2 <0.8 <0.2 <0.2 E0.0210 <0.2 E0.403 0.222

Route 2 <0.8 <0.2 <0.2 <0.2 <0.2 E0.397 <0.2

Route 119 E0.784 <0.2 <0.2 <0.2 <0.2 <1.6 E0.146

Route 119 <0.8 <0.2 <0.2 <0.2 <0.2 <1.6 <0.2

Route 119 1.14 <0.2 <0.2 <0.2 <1.6 <0.2
170 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued [USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute] Highway 5-Methyl- 1H-benzotriazole (μg/L) Acetophenone (μg/L) Acetyl hexamethyl tetrahydro naphthalene (μg/L) Anthracene (μg/L) 9,10-Anthraquinone (μg/L) Atrazine (μg/L) BDE congener 47 (μg/L) Interstate 93 E1.50 0.431 <0.2 E0.0897 0.301 <0.2 <0.2 Interstate 93 E1.57 0.304 <0.2 E0.166 0.556 <0.2 -- Interstate 93 <1.6 1.04 <0.2 .384 1.64 <0.2 <0.2 Interstate 95 E0.585 0.296 <0.2 <0.2 E0.105 <0.2 <0.2 Interstate 95 <1.6 1 <0.2 E0.0545 0.386 <0.2 <0.2 Interstate 95 <1.6 E0.755 <0.2 E0.128 0.706 <0.2 <0.2 Interstate 495 E0.405 E0.178 <0.2 E0.0098 E0.103 <0.2 <0.2 Interstate 495 <1.6 <0.2 <0.2 E0.0454 0.255 <0.2 <0.2 Interstate 495 <1.6 <0.468 <0.2 E0.177 E0.446 <0.2 <0.2 Route 2 <1.6 E0.162 <0.2 <0.2 E0.0592 <0.2 <0.2 Route 2 <1.6 <0.2 <0.2 <0.2 E0.195 <0.2 <0.2 Route 2 E0.492 <0.326 <0.2 E0.0359 E0.150 <0.2 <0.2 Route 119 E0.599 E0.158 <0.2 <0.2 E0.0671 <0.2 <0.2 Route 119 <1.6 <0.2 <0.2 <0.2 E0.116 <0.2 <0.2

Route 119 <1.6 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2
Tables 16–21

171

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway Benzo[a]pyrene (μg/L) Benzophenone (μg/L) beta-Sitosterol (μg/L) beta-Stigmastanol (μg/L) beta-Stigmastanol (μg/L) # P62816 Bisphenol A (μg/L) Bisphenol A-d3, surrogate (percent recovery)

Interstate 93 0.332 E0.0738 E2.58 <3.20 5.85 1.15 97.6

Interstate 93 0.973 <0.2 E7.68 -- 17.7 0.916 101Interstate 93 <1.29 <0.349 E5.04 <2.97 E17.6 1.24 91.2Interstate 95 E0.0471 <0.2 <0.8 <0.8 <2 E0.242 72.6Interstate 95 0.348 <0.2 E0.840 <0.8 5.56 E0.260 50.8Interstate 95 0.861 <0.2 E2.29 <0.8 <12.0 0.446 93.8Interstate 495 E0.0708 <0.2 E1.07 <0.8 <2 E0.255 98Interstate 495 E0.175 <0.2 E1.14 <0.8 E3.03 E0.293 85.9Interstate 495 E0.677 <0.2 E1.23 <0.8 <7.00 E0.486 53.2Route 2 <0.2 <0.2 <1.60 <1.60 2.97 E0.309 109Route 2 E0.0906 <0.2 E0.754 <0.8 E4.34 E0.313 97.3Route 2 E0.194 E0.0507 E2.18 E0.766 E2.91 E0.179 98.7Route 119 E0.0460 <0.2 E1.72 <0.8 2.53 E0.200 154

Route 119 E0.0472 <0.2 E0.402 <0.8 E1.20 E0.0607 96.2

Route 119 <0.2 <0.2 E0.971 <0.8 E1.38 <0.4 86.8
172 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued [USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute] Highway Bromacil (μg/L) Caffeine (μg/L) Caffeine-13C, surrogate (percent recovery) Camphor (μg/L) Carbaryl (μg/L) Carbazole (μg/L) Chlorpyrifos (μg/L) Cholesterol (μg/L) Cotinine (μg/L) Decafluoro- biphenyl, surrogate (percent recovery) Interstate 93 <0.2 0.618 81.6 E0.0474 <0.2 E0.0803 <0.2 2.17 E0.310 57.1 Interstate 93 <0.2 1.13 90 E0.130 <0.2 0.254 <0.2 E5.17 E0.410 66.6 Interstate 93 <0.747 E1.47 110 E0.194 <0.2 0.68 <0.2 <3.40 <0.8 71.6 Interstate 95 <0.2 E0.190 74.2 E0.0302 <0.2 E0.0251 <0.2 0.824 <0.8 57 Interstate 95 <0.2 0.392 56.2 E0.0856 <0.2 E0.144 <0.2 E0.576 <0.8 64.7 Interstate 95 <0.2 0.528 97.7 E0.0635 <0.2 0.293 <0.2 E1.27 <0.216 68.6 Interstate 495 <0.2 E0.162 67.5 E0.0781 <0.2 E0.0228 <0.2 1.61 <0.8 47 Interstate 495 <0.2 0.306 78.7 E0.0913 <0.2 E0.0800 <0.2 E1.26 <0.8 45 Interstate 495 <0.2 <0.2 45.9 E0.0512 <0.2 E0.235 <0.2 E1.25 <0.8 47.2 Route 2 <0.2 E0.0634 81.2 E0.120 <0.2 <0.2 <0.2 E0.492 <0.8 74.5 Route 2 <0.2 E0.114 81.2 E0.0985 <0.2 E0.0569 <0.2 E0.488 <0.8 56.6 Route 2 <0.2 E0.113 91.8 0.319 <0.2 E0.0567 <0.2 E1.69 E0.167 76 Route 119 <0.2 E0.124 111 <0.2 <0.2 E0.0146 <0.2 E2.68 <0.8 80.2 Route 119 <0.2 <0.2 79.3 E0.0924 <0.2 <0.2 <0.2 E0.414 <0.8 59.1

Route 119 <0.2 <0.2 97.5 E0.155 <0.2 <0.2 <0.2 E1.51 <0.8 80.4
Tables 16–21

173

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway

N,N-diethylmeta-toluamide 

(DEET)

(μg/L)

Diazinon

(μg/L)

Dichlorvos

(μg/L)

Diethoxynonylphenol

(Nonylphenol

monoethoxylate; 

NP1EO)

(sum of all isomers)

(μg/L)

Diethoxy

octylphenol

(4-tert-Octylphenol

diethoxylate;

OP2EO)

(μg/L)

Diethyl

phthalate

(μg/L)

D-Limonene

(μg/L)

Fluoranthene

(μg/L)

Interstate 93 0.318 <0.2 <0.2 E1.61 <0.32 E0.180 E0.104 0.733Interstate 93 0.287 <0.2 <0.2 E4.43 <0.32 0.262 <0.2 2.49Interstate 93 <0.2 <0.2 <0.2 <3.2 <0.644 0.276 E0.175 E8.14

Interstate 95 E0.119 <0.2 <0.2 <3.2 <0.32 <0.2 <0.2 E0.0763

Interstate 95 E0.0277 <0.2 <0.2 <3.2 <0.32 E0.161 E0.0363 1.04

Interstate 95 <0.2 <0.2 <0.2 <3.2 <0.32 0.236 <0.2 2.39Interstate 495 0.264 <0.2 <0.2 E1.53 E0.129 <0.2 E0.0209 E0.121

Interstate 495 <0.2 <0.2 <0.2 <3.2 <0.32 <0.2 <0.2 0.39Interstate 495 <0.2 <0.2 <0.2 <3.2 E0.256 <0.2 <0.2 E1.90Route 2 E0.142 <0.2 <0.400 <3.2 <0.32 <0.2 <0.2 E0.0406

Route 2 <0.2 <0.2 <0.2 <3.2 <0.32 <0.2 <0.2 0.236Route 2 E0.0956 <0.2 E0.0416 E0.826 <0.32 <0.2 <0.2 0.344

Route 119 E0.0972 <0.2 <0.2 E1.14 E0.110 E0.115 <0.2 E0.0555

Route 119 <0.2 <0.2 <0.2 <3.2 <0.32 <0.2 E0.0428 E0.143

Route 119 <0.2 <0.2 <0.2 <3.2 <0.32 <0.2 <0.2 E0.266
174 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued [USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute] Highway Fluoranthene-d10, surrogate (percent recovery) Hexahydro- hexamethyl cyclopenta- benzopyran (μg/L) Indole (μg/L) Isoborneol (μg/L) Isophorone (μg/L) Isoquinoline (μg/L) Menthol (μg/L) Metalaxyl (μg/L) Methyl salicylate (μg/L) Metolachlor (μg/L) Interstate 93 83.5 <0.2 E0.0336 <0.2 E0.0321 <0.2 <0.2 <0.2 E0.0158 <0.2 Interstate 93 87.9 <0.2 <0.2 <0.2 <0.2 <0.2 0.206 <0.2 <0.2 <0.2 Interstate 93 118 <0.2 <0.2 <0.2 E0.103 <0.407 E2.40 <0.2 <0.2 <0.2 Interstate 95 74.8 <0.2 <0.2 <0.2 E0.0276 <0.2 <0.2 <0.2 E0.0480 <0.2 Interstate 95 52.5 <0.2 <0.2 <0.2 E0.135 <0.2 0.676 <0.2 E0.0488 <0.2 Interstate 95 89.3 <0.2 <0.2 <0.2 <0.2 <0.2 0.289 <0.2 <0.2 <0.2 Interstate 495 66.1 <0.2 <0.2 <0.2 E0.0227 <0.2 <0.2 <0.2 <0.2 <0.2 Interstate 495 65.6 <0.2 <0.2 <0.2 E0.0353 <0.2 <0.2 <0.2 <0.2 <0.2 Interstate 495 53.1 <0.2 <0.2 <0.2 <0.2 <0.2 E0.190 <0.2 <0.2 <0.2 Route 2 84.8 <0.2 <0.2 <0.2 E0.0288 <0.400 E0.134 <0.2 E0.0647 <0.2 Route 2 68.7 <0.2 <0.2 <0.2 E0.0333 <0.2 E0.154 <0.2 <0.2 <0.2 Route 2 90.4 <0.2 <0.2 <0.2 E0.0668 <0.2 <0.2 E0.0969 <0.2 Route 119 87.3 <0.2 <0.2 <0.2 E0.0215 <0.2 <0.2 <0.2 E0.0485 <0.2 Route 119 80.4 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2

Route 119 90 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2
Tables 16–21

175

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway

Monoethoxynonylphenol

(4-Nonylphenol 

monoethoxylate; 

NP1EO)

(sum of all isomers)

(μg/L)

Monoethoxyoctylphenol

(4-tert-Octylphenol 

monoethoxylate;

OP1EO)

(μg/L)

p-Cresol

(μg/L)

Pentachlorophenol

(μg/L)

Phenanthrene

(μg/L)

Phenol

(μg/L)

Prometon

(μg/L)

Interstate 93 <2 <1 E0.0749 E1.10 0.236 E0.148 <0.2

Interstate 93 E1.61 <1 E0.141 E0.483 1.15 E0.174 <0.2Interstate 93 <2 <0.574 <1.37 <0.8 3.21 E1.81 <0.2

Interstate 95 <2 <1 E0.0560 E0.325 E0.0263 <0.2 <0.2

Interstate 95 <2 <1 0.237 E0.207 0.575 0.36 <0.2

Interstate 95 <2 <1 <0.424 <0.8 1.08 0.483 <0.2

Interstate 495 E0.328 <1 E0.0644 E0.283 E0.0514 <0.2 <0.2Interstate 495 E0.556 <1 E0.0919 E0.291 0.217 0.204 <0.2Interstate 495 <2 <1 <0.403 <0.8 E1.17 E0.814 <0.2

Route 2 <2 <1 <0.400 <8.00 E0.0242 <0.400 <0.2

Route 2 E0.346 <1 0.319 E0.186 E0.117 0.582 <0.2

Route 2 <2 <1 E0.197 E0.834 E0.160 0.494 <0.2

Route 119 <2 <1 E0.0420 <1.60 E0.0309 <0.2 <0.2

Route 119 <2 <1 E0.125 <0.8 E0.0694 0.278 <0.2

Route 119 <2 <1 0.246 <0.8 <0.2 0.645 <0.2
176 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07.—Continued [USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute] Highway Pyrene (μg/L) Tributyl phosphate (μg/L) Triclosan (μg/L) Triethyl citrate (μg/L) Triphenyl phosphate (μg/L) Tris(2-butoxy- ethyl) phosphate (μg/L) Tris(2-chloro- ethyl) phosphate (μg/L) Tris(dichloro- isopropyl) phosphate (μg/L) 1,4-Dichloro- benzene (μg/L) Interstate 93 0.635 <0.2 <0.2 <0.2 E0.129 0.327 E0.152 E0.162 <0.2 Interstate 93 2.16 E0.125 <0.2 <0.2 0.237 E0.894 E0.130 0.387 <0.2 Interstate 93 6 <0.233 <0.2 <0.2 <0.369 <0.2 0.284 <0.433 <0.2 Interstate 95 E0.0722 <0.2 <0.2 <0.2 E0.0586 <0.2 E0.100 E0.0899 <0.2 Interstate 95 0.753 <0.2 <0.2 <0.2 E0.0408 E0.240 E0.0425 E0.0709 <0.2 Interstate 95 1.81 <0.2 <0.2 <0.2 <0.2 E0.421 <0.2 E0.155 <0.2 Interstate 495 E0.128 <0.2 <0.2 <0.2 E0.0677 E0.148 E0.0713 E0.0844 E0.0079 Interstate 495 0.316 E0.0361 <0.2 <0.2 E0.0645 E0.279 E0.0416 E0.0969 <0.2 Interstate 495 E1.41 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 Route 2 E0.0355 <0.2 <0.400 <0.2 E0.0580 <0.2 E0.0586 E0.0619 <0.2 Route 2 0.207 E0.0906 <0.2 <0.2 E0.0588 E0.286 E0.0437 E0.120 <0.2 Route 2 0.321 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 E0.0829 <0.2 Route 119 E0.0546 <0.2 <0.2 <0.2 E0.0626 E0.122 E0.0579 E0.0500 <0.2 Route 119 E0.108 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 Route 119 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2
Tables 16–21

177

Table 17. Physical properties and concentrations of anthropogenic and natural organic compounds in unfiltered composite samples of highway runoff collected during three storms from five highways in Massachusetts, 2006–07—Continued.[USGS, U.S. Geological Survey; NTRU, nephelometric turbidity ratio units; μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; <, concentration shown is less than the laboratory reporting limit; E, the recovery or variation in recovery of the analyte is outside the acceptable range or the concentration reported is less than laboratory reporting level and is qualified as estimated; mm/dd/yyyy, month/day/year; hrmn, hour minute]

Highway

Isopropylbenzene,

(μg/L)

Naphthalene,

(μg/L)

Tetrachloroethene

(μg/L)

Tribromomethane

(μg/L)

Interstate 93 <0.2 E0.0300 <0.4 <0.2

Interstate 93 <0.2 E0.0739 <0.4 <0.2

Interstate 93 <0.2 E0.286 <0.4 <0.2

Interstate 95 <0.2 <0.2 <0.4 <0.2Interstate 95 <0.2 E0.0605 <0.4 <0.2

Interstate 95 <0.2 E0.0925 <0.4 <0.2

Interstate 495 <0.2 <0.2 <0.4 <0.2Interstate 495 <0.2 E0.0310 <0.4 <0.2

Interstate 495 <0.2 E0.0661 <0.4 <0.2

Route 2 <0.2 <0.2 <0.4 <0.2Route 2 <0.2 <0.2 <0.4 E0.0049Route 2 <0.2 <0.2 <0.4 <0.2Route 119 <0.2 <0.2 <0.4 <0.2Route 119 <0.2 <0.2 <0.4 E0.0090Route 119 <0.2 <0.2 <0.4 <0.2
178 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Antimony

(ppm)

Aluminum

(%)

Arsenic

(ppm)

Barium

(ppm)

Beryllium

(ppm)

Route 119 Suspended sediment < 0.063 mm <5 1.91 39 79 0.8

Route 119 Suspended sediment 0.063 ≤ 0.250 mm <5 1.59 19 87 0.5

Route 119 Suspended sediment ≥ 0.250 mm <5 0.89 22 55 <0.5

Route 2 Suspended sediment < 0.063 mm 9 2.81 29 157 1.1

Route 2 Suspended sediment 0.063 ≤ 0.250 mm <5 0.15 3 19 <0.5

Route 2 Suspended sediment ≥ 0.250 mm <5 0.27 3 27 <0.5

Interstate 495 Suspended sediment < 0.063 mm 7 2.32 21 615 0.9

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm <5 1.36 17 314 0.6

Interstate 495 Suspended sediment ≥ 0.250 mm <5 0.77 13 101 <0.5

Interstate 95 Suspended sediment < 0.063 mm 10 2.03 20 268 0.9

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm <5 0.99 9 109 <0.5

Interstate 95 Suspended sediment ≥ 0.250 mm <5 0.75 6 47 <0.5

Route 119 Maintenance sand W <5 0.74 5 46 <0.5

Route 119 Maintenance sand W <5 0.82 5 50 <0.5

Route 2 Maintenance sand W <5 0.49 <3 30 <0.5

Route 2 Maintenance sand W <5 0.63 <3 38 <0.5

Interstate 495 Maintenance sand W <5 0.57 <3 37 <0.5

Interstate 495 Maintenance sand W <5 0.54 <3 33 <0.5

Interstate 95 Maintenance sand W <5 0.3 11 19 <0.5

Interstate 95 Maintenance sand W <5 0.27 15 15 <0.5

Interstate 95 Road salt (sodium chloride) W <5 0.02 <3 3 <0.5

Interstate 495 Roadside grasses W <5 0.2 4 33 <0.5

Interstate 495 Roadside grasses W <5 0.18 <3 31 <0.5

Route 119 Pine needles W <5 0.05 <3 26 <0.5
Tables 16–21 179

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Bismuth

(ppm)

Calcium

(%)

Cadmium

(ppm)

Cobalt

(ppm)

Chromium

(ppm)

Route 119 Suspended sediment < 0.063 mm <5 0.25 <1 19 147

Route 119 Suspended sediment 0.063 ≤ 0.250 mm <5 0.27 <1 13 687

Route 119 Suspended sediment ≥ 0.250 mm <5 0.33 <1 11 3,470

Route 2 Suspended sediment < 0.063 mm <5 0.35 1 15 391

Route 2 Suspended sediment 0.063 ≤ 0.250 mm <5 0.1 <1 <1 65

Route 2 Suspended sediment ≥ 0.250 mm <5 0.22 <1 2 70

Interstate 495 Suspended sediment < 0.063 mm <5 0.34 1 14 136

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm <5 0.39 <1 10 1,690

Interstate 495 Suspended sediment ≥ 0.250 mm <5 0.3 <1 6 1,050

Interstate 95 Suspended sediment < 0.063 mm <5 0.51 2 15 381

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm <5 0.62 <1 7 134

Interstate 95 Suspended sediment ≥ 0.250 mm <5 0.5 <1 5 395

Route 119 Maintenance sand W <5 0.11 <1 3 325

Route 119 Maintenance sand W <5 0.12 <1 3 361

Route 2 Maintenance sand W <5 0.07 <1 1 273

Route 2 Maintenance sand W <5 0.08 <1 2 308

Interstate 495 Maintenance sand W <5 0.12 <1 2 306

Interstate 495 Maintenance sand W <5 0.13 <1 2 321

Interstate 95 Maintenance sand W <5 0.04 <1 2 421

Interstate 95 Maintenance sand W <5 0.03 <1 2 329

Interstate 95 Road salt (sodium chloride) W <5 0.26 <1 <1 12

Interstate 495 Roadside grasses W <5 0.33 <1 2 483

Interstate 495 Roadside grasses W <5 0.25 <1 1 227

Route 119 Pine needles W <5 0.47 <1 <1 34
180 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Copper

(ppm)

Iron

(%)

Lanthanum

(ppm)

Lead

(ppm)

Lithium

(ppm)

Route 119 Suspended sediment < 0.063 mm 95.8 3.96 28.1 74 50

Route 119 Suspended sediment 0.063 ≤ 0.250 mm 65.2 2.91 15.6 33 32

Route 119 Suspended sediment ≥ 0.250 mm 68.2 3.47 9.7 20 14

Route 2 Suspended sediment < 0.063 mm 218 4.89 32.6 157 69

Route 2 Suspended sediment 0.063 ≤ 0.250 mm 17.5 0.52 5.6 7 2

Route 2 Suspended sediment ≥ 0.250 mm 15.6 1.4 5.8 8 4

Interstate 495 Suspended sediment < 0.063 mm 248 3.85 24.8 108 67

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm 159 3.39 14.6 51 27

Interstate 495 Suspended sediment ≥ 0.250 mm 78 2.99 8.9 19 13

Interstate 95 Suspended sediment < 0.063 mm 391 4.22 23.7 200 47

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm 209 2.73 11.7 251 14

Interstate 95 Suspended sediment ≥ 0.250 mm 44.2 2.57 15.4 45 14

Route 119 Maintenance sand W 16.1 1.21 19.8 15 10

Route 119 Maintenance sand W 10.3 1.25 20.7 8 10

Route 2 Maintenance sand W 8.9 0.82 12 5 6

Route 2 Maintenance sand W 9.1 0.98 15.1 5 6

Interstate 495 Maintenance sand W 6.8 0.8 16.8 4 6

Interstate 495 Maintenance sand W 7.1 0.85 16.6 4 6

Interstate 95 Maintenance sand W 7.3 1.69 10.6 7 2

Interstate 95 Maintenance sand W 6.1 2.26 10.5 7 1

Interstate 95 Road salt (sodium chloride) W 1.1 0.05 0.7 <2 <1

Interstate 495 Roadside grasses W 23.7 0.65 3.2 12 3

Interstate 495 Roadside grasses W 18 0.43 2 11 3

Route 119 Pine needles W 2.1 0.04 <0.5 7 <1
Tables 16–21 181

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Magnesium

(%)

Manganese

(ppm)

Molybdenum

(ppm)

Nickel

(ppm)

Phosphorus

(%)

Route 119 Suspended sediment < 0.063 mm 1.24 589 5 46 0.1

Route 119 Suspended sediment 0.063 ≤ 0.250 mm 0.72 477 7 41 0.06

Route 119 Suspended sediment ≥ 0.250 mm 0.29 553 12 54 0.04

Route 2 Suspended sediment < 0.063 mm 1.92 703 11 53 0.11

Route 2 Suspended sediment 0.063 ≤ 0.250 mm 0.06 99 1 5 0.01

Route 2 Suspended sediment ≥ 0.250 mm 0.13 145 2 16 0.01

Interstate 495 Suspended sediment < 0.063 mm 1.88 621 11 51 0.09

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm 0.67 504 13 49 0.05

Interstate 495 Suspended sediment ≥ 0.250 mm 0.3 415 11 40 0.03

Interstate 95 Suspended sediment < 0.063 mm 1.14 957 17 63 0.13

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm 0.46 297 7 35 0.08

Interstate 95 Suspended sediment ≥ 0.250 mm 0.35 301 6 24 0.04

Route 119 Maintenance sand W 0.21 304 6 9 0.04

Route 119 Maintenance sand W 0.2 329 6 9 0.04

Route 2 Maintenance sand W 0.1 198 2 8 0.03

Route 2 Maintenance sand W 0.14 220 2 7 0.03

Interstate 495 Maintenance sand W 0.12 208 5 7 0.04

Interstate 495 Maintenance sand W 0.12 231 13 8 0.04

Interstate 95 Maintenance sand W 0.06 108 2 9 0.03

Interstate 95 Maintenance sand W 0.07 88 3 9 0.05

Interstate 95 Road salt (sodium chloride) W 1.56 15 <1 <1 <0.01

Interstate 495 Roadside grasses W 0.27 265 4 14 0.27

Interstate 495 Roadside grasses W 0.23 246 2 7 0.22

Route 119 Pine needles W 0.05 1,150 <1 2 0.04
182 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Potassium

(%)

Scandium

(ppm)

Silver

(ppm)

Sodium

(%)

Tin

(ppm)

Route 119 Suspended sediment < 0.063 mm 0.36 4.2 <0.2 0.13 <10

Route 119 Suspended sediment 0.063 ≤ 0.250 mm 0.46 3.8 <0.2 0.11 <10

Route 119 Suspended sediment ≥ 0.250 mm 0.3 1.6 <0.2 0.16 <10

Route 2 Suspended sediment < 0.063 mm 0.54 6 <0.2 0.15 10

Route 2 Suspended sediment 0.063 ≤ 0.250 mm 0.04 <0.5 <0.2 0.02 <10

Route 2 Suspended sediment ≥ 0.250 mm 0.07 0.6 <0.2 0.03 <10

Interstate 495 Suspended sediment < 0.063 mm 0.4 5 <0.2 0.07 10

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm 0.33 3.6 <0.2 0.11 <10

Interstate 495 Suspended sediment ≥ 0.250 mm 0.21 1.7 <0.2 0.07 <10

Interstate 95 Suspended sediment < 0.063 mm 0.39 4.3 0.3 0.19 20

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm 0.17 1.8 <0.2 0.07 <10

Interstate 95 Suspended sediment ≥ 0.250 mm 0.28 2.1 <0.2 0.06 <10

Route 119 Maintenance sand W 0.33 2.1 <0.2 0.05 <10

Route 119 Maintenance sand W 0.36 2.2 <0.2 0.05 <10

Route 2 Maintenance sand W 0.2 1.3 <0.2 0.04 <10

Route 2 Maintenance sand W 0.25 1.5 <0.2 0.05 <10

Interstate 495 Maintenance sand W 0.24 1.4 <0.2 0.05 <10

Interstate 495 Maintenance sand W 0.22 1.5 <0.2 0.06 <10

Interstate 95 Maintenance sand W 0.14 0.7 <0.2 0.07 <10

Interstate 95 Maintenance sand W 0.14 0.8 <0.2 0.27 <10

Interstate 95 Road salt (sodium chloride) W 0.37 <0.5 <0.2 >15 <10

Interstate 495 Roadside grasses W 0.97 <0.5 <0.2 0.21 <10

Interstate 495 Roadside grasses W 0.59 <0.5 <0.2 0.14 <10

Route 119 Pine needles W 0.12 <0.5 <0.2 0.01 <10
Tables 16–21 183

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Strontium

(ppm)

Thallium

(%)

Vanadium

(ppm)

Tungsten

(ppm)

Yttrium

(ppm)

Route 119 Suspended sediment < 0.063 mm 23.8 0.07 68 40 10.8

Route 119 Suspended sediment 0.063 ≤ 0.250 mm 21.3 0.09 60 20 6.6

Route 119 Suspended sediment ≥ 0.250 mm 28 0.04 35 <10 4.5

Route 2 Suspended sediment < 0.063 mm 39.2 0.09 93 <10 13.6

Route 2 Suspended sediment 0.063 ≤ 0.250 mm 4.6 0.02 5 <10 2.3

Route 2 Suspended sediment ≥ 0.250 mm 9.1 0.02 8 <10 2.4

Interstate 495 Suspended sediment < 0.063 mm 29.8 0.09 88 <10 12

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm 27.3 0.09 63 <10 7.8

Interstate 495 Suspended sediment ≥ 0.250 mm 18.2 0.03 24 <10 4.8

Interstate 95 Suspended sediment < 0.063 mm 40.5 0.12 125 <10 11.8

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm 34.5 0.07 48 <10 6.2

Interstate 95 Suspended sediment ≥ 0.250 mm 35.8 0.08 27 <10 7.4

Route 119 Maintenance sand W 8.8 0.06 16 <10 6.5

Route 119 Maintenance sand W 10.4 0.06 16 <10 6.8

Route 2 Maintenance sand W 8 0.03 9 <10 4.5

Route 2 Maintenance sand W 10.1 0.04 12 <10 5.5

Interstate 495 Maintenance sand W 9.5 0.05 10 <10 5.7

Interstate 495 Maintenance sand W 8 0.05 11 <10 6

Interstate 95 Maintenance sand W 7.9 0.02 32 <10 4.6

Interstate 95 Maintenance sand W 6.8 0.02 47 <10 4.5

Interstate 95 Road salt (sodium chloride) W 120 <0.01 <2 <10 <0.5

Interstate 495 Roadside grasses W 27 0.01 6 <10 1.2

Interstate 495 Roadside grasses W 22 <0.01 5 <10 1

Route 119 Pine needles W 25.3 <0.01 <2 <10 <0.5
184 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 18. Concentrations of 32 elements and total organic carbon in samples of sieved suspended sediment, highway maintenance 

sand, road salt, roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[<, Less than the value shown; ≥, greater than or equal to the value shown; ≤, less than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; --, no data; ppm, parts per million; %, parts per hundred; TOC, total organic carbon]

Highway Sample type Particle-size

fraction

Zinc

(ppm)

Zirconium

(ppm)

TOC

(%)

Route 119 Suspended sediment < 0.063 mm 503 10.4 7.86

Route 119 Suspended sediment 0.063 ≤ 0.250 mm 247 6.8 7.56

Route 119 Suspended sediment ≥ 0.250 mm 200 5.3 10.2

Route 2 Suspended sediment < 0.063 mm 2,360 15.2 11.7

Route 2 Suspended sediment 0.063 ≤ 0.250 mm 46.6 1.8 12.3

Route 2 Suspended sediment ≥ 0.250 mm 83.9 3.4 12.2

Interstate 495 Suspended sediment < 0.063 mm 945 12.6 11.7

Interstate 495 Suspended sediment 0.063 ≤ 0.250 mm 363 8.2 7.69

Interstate 495 Suspended sediment ≥ 0.250 mm 135 6.7 2.78

Interstate 95 Suspended sediment < 0.063 mm 1,120 16.6 17.5

Interstate 95 Suspended sediment 0.063 ≤ 0.250 mm 403 6.1 17.1

Interstate 95 Suspended sediment ≥ 0.250 mm 86.8 11.3 1.08

Route 119 Maintenance sand W 31.2 4.5 --

Route 119 Maintenance sand W 20.1 4.7 --

Route 2 Maintenance sand W 11.7 4.1 --

Route 2 Maintenance sand W 14.4 4.7 --

Interstate 495 Maintenance sand W 12.3 4.8 --

Interstate 495 Maintenance sand W 12.9 4.5 --

Interstate 95 Maintenance sand W 12.5 6.9 --

Interstate 95 Maintenance sand W 11.8 6.7 --

Interstate 95 Road salt (sodium chloride) W 5.2 <0.5 --

Interstate 495 Roadside grasses W 76.6 0.5 --

Interstate 495 Roadside grasses W 67.7 <0.5 --

Route 119 Pine needles W 29.3 <0.5 --
Tables 16–21 185

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven highways 

in Massachusetts, 2005–07.

[Latitude and longitude: in degrees, minutes, and seconds; <, actual value is less than the value shown; mm, millimeters; ppm, parts per million; %, parts per 

hundred; -- no data]

Highway Sample 

number Latitude Longitude

Particles

< 0.063 mm

in diameter

(%)

Particles

< 0.25 mm

in diameter

(%)

Silver

(ppm)

Aluminum

(%)

Arsenic

(ppm)

Route 119 1 42 41 51.8 71 54 16.8 16 53 <0.2 1.36 19

Route 119 2 42 41 49.6 71 54 18.2 20 52 <0.2 0.6 11

Route 119 3 42 41 55.9 71 54 32.6 22 49 <0.2 0.36 4

Route 119 4 42 42 34.6 71 54 31.9 27 60 <0.2 1.86 8

Route 119 5 42 42 41.3 71 54 39.3 18 52 <0.2 1.54 6

Route 2 1 42 30 53.7 71 29 39.3 26 76 <0.2 1.53 10

Route 2 2 42 30 46.8 71 29 39.3 19 58 <0.2 1.36 11

Route 2 3 42 30 15.2 71 29 01.7 35 80 <0.2 2.09 6

Route 2 4 42 30 14.8 71 29 49.4 24 65 <0.2 1.74 8

Route 2 5 42 30 29.6 71 29 15.3 40 74 <0.2 1.73 9

Interstate 495 1 42 27 11.6 71 34 35.8 42 71 <0.2 2.18 14

Interstate 495 2 42 27 32.4 71 34 13.1 45 77 <0.2 2.03 10

Interstate 495 3 42 27 56.1 71 34 47.4 35 68 <0.2 1.61 12

Interstate 495 4 42 28 10.7 71 33 37.8 50 81 <0.2 2.61 11

Interstate 495 5 42 27 16.3 71 34 40.6 35 62 <0.2 2.16 20

Interstate 95 1 42 24 09.6 71 15 37.3 32 64 <0.2 1.9 6

Interstate 95 2 42 24 17.4 71 15 35.9 36 69 <0.2 2.06 6

Interstate 95 3 42 26 13.3 71 15 37.5 44 78 <0.2 1.72 8

Interstate 95 4 42 26 14.6 71 15 37.1 43 76 <0.2 1.64 8

Interstate 95 5 42 25 17.8 71 16 22.4 29 63 <0.2 1.29 9

Route 8 1 42 40 47.9 73 06 25.1 -- -- <0.2 1.51 9

Route 8 2 42 40 46.6 73 06 25.6 -- -- <0.2 1.97 10

Route 8 3 42 40 32.1 73 06 28.9 -- -- 1 0.5 4

Route 8 4 42 40 30.4 73 06 29.5 -- -- <0.2 2.15 10

Route 8 5 42 40 26.9 73 06 29.4 -- -- <0.2 1.94 6

Interstate 93 1 42 16 01.5 71 02 48.4 -- -- <0.2 1.11 6

Interstate 93 2 42 16 05.8 71 02 50.8 -- -- <0.2 1.29 4

Interstate 93 3 42 16 48.6 71 02 46.6 -- -- <0.2 1.11 4

Interstate 93 4 42 16 52.0 71 02 48.0 -- -- <0.2 1.17 10

Interstate 93 5 42 16 03.0 71 02 53.2 -- -- <0.2 1.05 6

Interstate 195 1 41 43 57.3 70 46 13.3 -- -- <0.2 0.57 <3

Interstate 195 2 41 43 46.7 70 46 19.2 -- -- <0.2 0.64 3

Interstate 195 3 41 43 41.8 70 46 23.0 -- -- <0.2 0.26 3

Interstate 195 4 41 44 17.8 70 45 56.3 -- -- <0.2 0.46 <3

Interstate 195 5 41 44 23.5 70 45 23.5 -- -- <0.2 0.69 <3
186 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven highways 

in Massachusetts, 2005–07.—Continued

[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred; 

-- no data]

Highway Sample 

number

Silver

(ppm)

Aluminum

(%)

Arsenic

(ppm)

Barium

(ppm)

Beryllium

(ppm)

Bismuth

(ppm)

Calcium

(%)

Cadmium

(ppm)

Route 119 1 <0.2 1.36 19 43 0.6 <5 0.05 <1

Route 119 2 <0.2 0.6 11 28 <0.5 <5 0.03 <1

Route 119 3 <0.2 0.36 4 26 <0.5 <5 0.02 <1

Route 119 4 <0.2 1.86 8 46 0.8 <5 0.06 <1

Route 119 5 <0.2 1.54 6 41 <0.5 <5 0.05 <1

Route 2 1 <0.2 1.53 10 45 0.5 <5 0.11 <1

Route 2 2 <0.2 1.36 11 55 <0.5 <5 0.26 <1

Route 2 3 <0.2 2.09 6 92 1.3 <5 0.22 <1

Route 2 4 <0.2 1.74 8 45 0.6 <5 0.12 <1

Route 2 5 <0.2 1.73 9 42 0.7 <5 0.11 <1

Interstate 495 1 <0.2 2.18 14 48 0.6 <5 0.14 <1

Interstate 495 2 <0.2 2.03 10 40 0.5 <5 0.16 <1

Interstate 495 3 <0.2 1.61 12 40 <0.5 <5 0.14 <1

Interstate 495 4 <0.2 2.61 11 36 0.6 <5 0.1 <1

Interstate 495 5 <0.2 2.16 20 53 0.7 <5 0.1 <1

Interstate 95 1 <0.2 1.9 6 42 0.5 <5 0.54 <1

Interstate 95 2 <0.2 2.06 6 41 0.9 <5 0.3 <1

Interstate 95 3 <0.2 1.72 8 38 0.6 <5 0.12 <1

Interstate 95 4 <0.2 1.64 8 27 <0.5 <5 0.1 <1

Interstate 95 5 <0.2 1.29 9 31 <0.5 <5 0.21 <1

Route 8 1 <0.2 1.51 9 125 <0.5 <5 0.25 <1

Route 8 2 <0.2 1.97 10 80 0.6 <5 0.37 <1

Route 8 3 1 0.5 4 37 <0.5 <5 >15 <1

Route 8 4 <0.2 2.15 10 74 <0.5 <5 0.4 <1

Route 8 5 <0.2 1.94 6 126 <0.5 <5 0.5 <1

Interstate 93 1 <0.2 1.11 6 48 <0.5 <5 0.24 <1

Interstate 93 2 <0.2 1.29 4 37 <0.5 <5 0.25 <1

Interstate 93 3 <0.2 1.11 4 42 <0.5 <5 0.26 <1

Interstate 93 4 <0.2 1.17 10 203 0.6 <5 0.31 1

Interstate 93 5 <0.2 1.05 6 45 <0.5 <5 0.15 <1

Interstate 195 1 <0.2 0.57 <3 14 <0.5 <5 0.02 <1

Interstate 195 2 <0.2 0.64 3 14 <0.5 <5 0.04 <1

Interstate 195 3 <0.2 0.26 3 12 <0.5 <5 0.03 <1

Interstate 195 4 <0.2 0.46 <3 13 <0.5 <5 0.03 <1

Interstate 195 5 <0.2 0.69 <3 13 <0.5 <5 0.08 <1
Tables 16–21 187

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven highways 

in Massachusetts, 2005-07.—Continued

[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred; 

-- no data]

Highway Sample 

number

Cobalt

(ppm)

Chromium

(ppm)

Copper

(ppm)

Iron

(%)

Potassium

(%)

Lanthanum

(ppm)

Route 119 1 2 413 11.2 1.62 0.22 20.4

Route 119 2 3 1540 14.3 1.61 0.16 19.7

Route 119 3 1 784 12 0.73 0.11 15.3

Route 119 4 3 649 10.5 1.84 0.19 26.1

Route 119 5 2 720 8.8 2.14 0.17 26.1

Route 2 1 4 384 11 1.53 0.17 22.4

Route 2 2 8 655 15.2 1.82 0.31 22.4

Route 2 3 6 408 20.1 1.85 0.15 29.7

Route 2 4 4 407 12.6 1.62 0.16 22.1

Route 2 5 4 564 11.6 1.73 0.14 24

Interstate 495 1 6 338 13.7 2 0.21 27.8

Interstate 495 2 4 1140 14.2 2.54 0.16 20.3

Interstate 495 3 4 438 12.5 1.76 0.18 15.9

Interstate 495 4 5 240 7.9 2.05 0.16 25.7

Interstate 495 5 4 527 11.7 2.31 0.22 25.5

Interstate 95 1 10 209 27.3 2.51 0.17 18.9

Interstate 95 2 7 521 20.6 2.25 0.13 26

Interstate 95 3 4 276 9.6 1.41 0.11 23.9

Interstate 95 4 3 246 11.5 1.42 0.1 20.9

Interstate 95 5 5 1090 21.9 2.29 0.11 12.6

Route 8 1 12 158 32.1 2.98 0.18 30.7

Route 8 2 14 185 24.5 3.27 0.25 34

Route 8 3 3 244 11.8 0.74 0.15 7.7

Route 8 4 14 255 28.8 3.73 0.28 18.3

Route 8 5 13 281 24.9 3.53 0.23 18.3

Interstate 93 1 5 464 56.9 2.12 0.2 17.2

Interstate 93 2 4 457 33 1.86 0.24 22.9

Interstate 93 3 5 195 40.5 1.87 0.16 17.8

Interstate 93 4 8 390 167 3.53 0.2 18

Interstate 93 5 4 183 79.8 1.91 0.15 20.9

Interstate 195 1 1 298 4.5 1.01 0.06 9.3

Interstate 195 2 1 447 5.9 1.03 0.07 13.4

Interstate 195 3 1 548 6.9 0.76 0.05 11.8

Interstate 195 4 <1 250 3.5 0.47 0.05 7.6

Interstate 195 5 1 253 2.7 0.45 0.06 10.5
188 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven 

highways in Massachusetts, 2005-07.—Continued

[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred; 

-- no data]

Highway Sample 

number

Lithium

(ppm)

Magnesium

(%)

Manganese

(ppm)

Molybdenum

(ppm)

Sodium

(%)

Nickel

(ppm)

Route 119 1 23 0.11 196 4 0.03 13

Route 119 2 8 0.03 215 5 0.02 19

Route 119 3 3 0.01 134 5 0.01 17

Route 119 4 14 0.12 298 4 0.04 14

Route 119 5 9 0.06 237 6 0.03 18

Route 2 1 13 0.26 272 2 0.03 17

Route 2 2 14 0.39 440 5 0.06 30

Route 2 3 16 0.38 997 2 0.04 23

Route 2 4 15 0.25 175 3 0.04 21

Route 2 5 14 0.24 281 3 0.04 18

Interstate 495 1 18 0.36 296 3 0.04 24

Interstate 495 2 17 0.22 257 4 0.05 27

Interstate 495 3 16 0.24 246 4 0.04 21

Interstate 495 4 20 0.34 172 2 0.03 20

Interstate 495 5 25 0.32 253 3 0.04 20

Interstate 95 1 13 0.54 286 2 0.07 22

Interstate 95 2 13 0.36 301 4 0.05 20

Interstate 95 3 12 0.21 215 3 0.04 14

Interstate 95 4 12 0.21 156 3 0.03 14

Interstate 95 5 8 0.22 305 4 0.05 23

Route 8 1 24 0.42 870 2 0.03 26

Route 8 2 29 0.52 1020 2 0.03 31

Route 8 3 6 0.27 542 3 0.02 14

Route 8 4 39 0.7 679 3 0.03 37

Route 8 5 34 0.61 2130 2 0.03 28

Interstate 93 1 11 0.29 268 5 0.09 22

Interstate 93 2 27 0.3 259 4 0.11 15

Interstate 93 3 12 0.3 323 2 0.04 16

Interstate 93 4 15 0.28 431 4 0.07 25

Interstate 93 5 14 0.27 188 4 0.03 23

Interstate 195 1 2 0.03 52 2 0.01 6

Interstate 195 2 3 0.03 78 3 0.02 11

Interstate 195 3 <1 0.02 85 3 0.02 9

Interstate 195 4 2 0.03 52 2 0.02 7

Interstate 195 5 4 0.05 71 1 0.01 5
Tables 16–21 189

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven highways 

in Massachusetts, 2005-07—Continued

[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred; 

-- no data]

Highway Sample 

number

Phosphorus

(%)

Lead

(ppm)

Antimony

(ppm)

Scandium

(ppm)

Tin

(ppm)

Strontium

(ppm)

Route 119 1 0.05 47 <5 1.5 <10 5.8

Route 119 2 0.04 22 <5 0.7 <10 4.1

Route 119 3 0.02 10 <5 <0.5 <10 4.5

Route 119 4 0.04 15 <5 2.6 <10 8.1

Route 119 5 0.04 20 <5 1.8 <10 7

Route 2 1 0.07 25 <5 1.9 <10 10.2

Route 2 2 0.07 21 <5 2.8 <10 19.4

Route 2 3 0.16 30 <5 1.6 <10 14

Route 2 4 0.06 65 <5 1.8 <10 10.1

Route 2 5 0.09 24 <5 1.8 <10 9.1

Interstate 495 1 0.06 23 <5 2.5 <10 11.2

Interstate 495 2 0.04 43 <5 1.9 <10 13.6

Interstate 495 3 0.05 90 <5 1.8 <10 11.9

Interstate 495 4 0.04 22 <5 2.9 <10 8.4

Interstate 495 5 0.05 21 <5 2.4 <10 10.6

Interstate 95 1 0.11 120 <5 3.9 <10 25.3

Interstate 95 2 0.1 29 <5 2.7 <10 15.8

Interstate 95 3 0.08 52 <5 2.3 <10 8.2

Interstate 95 4 0.1 80 <5 1.9 <10 7.2

Interstate 95 5 0.09 60 <5 1.5 <10 16.4

Route 8 1 0.08 212 <5 2.5 <10 10.1

Route 8 2 0.09 33 <5 3.1 <10 10.9

Route 8 3 0.09 35 <5 0.8 <10 151

Route 8 4 0.09 44 <5 2.4 <10 12.3

Route 8 5 0.11 34 <5 2.2 <10 13.7

Interstate 93 1 0.08 171 <5 2.7 <10 29.8

Interstate 93 2 0.05 74 <5 2.9 <10 25.9

Interstate 93 3 0.09 202 <5 2.5 <10 27.2

Interstate 93 4 0.11 631 <5 2.6 230 35.1

Interstate 93 5 0.09 770 <5 2 <10 16.8

Interstate 195 1 0.02 14 <5 <0.5 <10 5.4

Interstate 195 2 0.02 17 <5 0.5 <10 6.7

Interstate 195 3 0.01 14 <5 <0.5 <10 5.4

Interstate 195 4 0.01 11 <5 <0.5 <10 6.1

Interstate 195 5 0.01 10 <5 1 <10 13.3
190 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 19. Distribution of particle sizes and concentrations of 32 elements measured in samples of soil collected near seven highways 

in Massachusetts, 2005-07—Continued

[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred; 

-- no data]

Highway Sample 

number

Thallium

(%)

Vanadium

(ppm)

Tungsten

(ppm)

Yttrium

(ppm)

Zinc

(ppm)

Zirconium

(ppm)

Route 119 1 0.05 26 <10 5.2 29.3 1.7

Route 119 2 0.03 20 <10 3.8 13.1 1.6

Route 119 3 0.02 7 <10 3.1 13.7 1.3

Route 119 4 0.08 25 <10 6.8 46 1.8

Route 119 5 0.07 31 <10 5.7 29.4 3.1

Route 2 1 0.08 25 <10 6.7 30.7 1.7

Route 2 2 0.11 30 <10 9.4 36.6 3.6

Route 2 3 0.1 29 <10 10.1 53.4 1.7

Route 2 4 0.1 33 <10 7.6 30.9 2

Route 2 5 0.09 27 <10 7.9 28.3 1.9

Interstate 495 1 0.11 34 <10 8.6 36.2 2.2

Interstate 495 2 0.13 41 <10 6.8 26.7 4.3

Interstate 495 3 0.1 34 <10 4.7 54.2 2.5

Interstate 495 4 0.13 38 <10 7.2 32.4 4.2

Interstate 495 5 0.09 33 <10 7.6 34.6 2.6

Interstate 95 1 0.21 81 <10 13.9 58.2 5.1

Interstate 95 2 0.14 51 <10 18.4 40 2.8

Interstate 95 3 0.09 27 <10 9.8 35.2 1.8

Interstate 95 4 0.08 34 <10 7.2 30.6 1.5

Interstate 95 5 0.1 48 <10 5.9 43.1 2.2

Route 8 1 0.02 19 <10 13.7 199 3.3

Route 8 2 0.03 25 <10 15.3 104 3.2

Route 8 3 0.01 14 <10 5.2 74.7 0.8

Route 8 4 0.03 33 <10 8.4 112 3.1

Route 8 5 0.03 29 <10 6.9 106 2.8

Interstate 93 1 0.09 42 <10 9 51.2 3.6

Interstate 93 2 0.1 36 <10 10.1 36.5 3.4

Interstate 93 3 0.1 36 <10 9.2 74.4 4.8

Interstate 93 4 0.08 40 <10 9.4 435 5.4

Interstate 93 5 0.07 60 <10 9.9 67.8 4.4

Interstate 195 1 0.03 16 <10 2.4 6.8 1.6

Interstate 195 2 0.04 17 <10 2.8 6.3 4.5

Interstate 195 3 0.04 12 <10 2.1 5.8 1.3

Interstate 195 4 0.04 8 <10 2.4 8.1 2.3

Interstate 195 5 0.05 14 <10 3.6 6.1 0.9
Tables 16–21

191

Table 20. Distribution of particle sizes and concentrations of 32 elements measured in samples of berm material collected at the edge of the pavement for four highways in Massachusetts, 2005–07.—Continued[Latitude and longitude: in degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred]

Highway Sample number Latitude Longitude

Particles

< 0.063 mm

in diameter

(percent)

Particles

< 0.25 mm

in diameter

(percent)

Silver

(ppm)

Aluminum

(%)

Arsenic

(ppm)

Barium

(ppm)

Beryllium

(ppm)

Bismuth

(ppm)

Calcium

(%)

Cadmium

(ppm)

Route 119 1 42 41 52.7 71 54 27.5 5.2 29.5 <0.2 0.64 13 31 <0.5 <5 0.19 <1

Route 119 2 42 41 55.9 71 54 32.6 8.9 35.4 <0.2 0.75 22 37 <0.5 <5 0.19 <1

Route 119 3 42 42 09.2 71 54 52.4 12.7 42.0 <0.2 0.8 21 34 <0.5 <5 0.17 <1

Route 119 4 42 42 08.7 71 54 52.8 6.8 27.7 <0.2 0.74 19 38 <0.5 <5 0.17 <1

Route 119 5 42 42 07.7 71 54 51.1 7.5 30.9 <0.2 0.78 20 38 <0.5 <5 0.18 <1

Route 2 1 42 30 59.0 71 29 56.6 6.2 37.0 <0.2 0.67 10 44 <0.5 <5 0.25 <1

Route 2 2 42 30 26.9 71 29 13.4 5.5 41.4 <0.2 0.74 9 54 <0.5 <5 0.39 <1

Route 2 3 42 30 16.6 71 28 59.2 3.5 32.1 <0.2 0.54 6 39 <0.5 <5 0.29 <1

Route 2 4 42 30 14.2 71 29 51.1 9.3 41.0 <0.2 0.61 9 42 <0.5 <5 0.23 <1

Route 2 5 42 30 27.3 71 29 12.8 4.9 47.7 <0.2 0.72 10 54 <0.5 <5 0.34 <1

Interstate 495 1 42 27 12.6 71 34 38.9 6.3 31.5 <0.2 0.67 9 87 <0.5 <5 0.5 <1

Interstate 495 2 42 27 57.4 71 33 47.1 6.3 28.9 <0.2 0.74 11 105 <0.5 <5 0.54 <1

Interstate 495 3 42 28 21.0 71 34 20.4 8.1 45.5 <0.2 0.83 19 150 <0.5 <5 0.54 <1

Interstate 495 4 42 28 19.9 71 33 21.6 8.5 42.7 <0.2 0.79 15 162 <0.5 <5 0.49 <1

Interstate 495 5 42 27 15.9 71 34 39.0 6.9 40.3 <0.2 0.71 11 70 <0.5 <5 0.4 <1

Interstate 95 1 42 27 06.6 71 15 36.1 6.1 36.9 <0.2 0.65 9 78 <0.5 <5 0.5 <1

Interstate 95 2 42 24 12.2 71 15 35.1 14.1 49.1 <0.2 0.95 12 59 <0.5 <5 0.44 <1

Interstate 95 3 42 26 11.0 71 15 37.2 6.3 21.2 <0.2 0.82 9 61 <0.5 <5 0.5 <1

Interstate 95 4 42 26 22.1 71 15 37.5 10.7 29.0 <0.2 0.96 9 60 <0.5 <5 0.63 <1

Interstate 95 5 42 26 25.3 71 15 31.4 4.9 20.6 <0.2 0.52 6 49 <0.5 <5 0.35 <1
192 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07 Table 20. Distribution of particle sizes and concentrations of 32 elements measured in samples of berm material collected at the edge of the pavement for four highways in Massachusetts, 2005–07.—Continued [Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred] Highway Sample number Cobalt (ppm) Chromium (ppm) Copper (ppm) Iron (%) Potassium (%) Lanthanum (ppm) Lithium (ppm) Magnesium (%) Manganese (ppm) Molybdenum (ppm) Sodium (%) Nickel (ppm) Route 119 1 3 223 22.4 1.3 0.2 15.3 9 0.21 241 3 0.04 12 Route 119 2 5 380 33.7 1.66 0.25 21.8 12 0.28 294 3 0.05 15 Route 119 3 4 480 36.4 1.7 0.21 22.2 11 0.23 343 9 0.05 16 Route 119 4 4 368 28.4 1.57 0.25 20.3 12 0.26 328 3 0.05 16 Route 119 5 5 530 33.2 1.73 0.26 21 12 0.28 359 10 0.05 18 Route 2 1 4 404 40.5 1.85 0.21 15.3 11 0.26 304 3 0.11 18 Route 2 2 4 664 91.3 2.09 0.22 16.5 12 0.3 388 12 0.07 23 Route 2 3 3 387 41.5 1.7 0.17 13.3 9 0.21 263 4 0.05 18 Route 2 4 4 439 60.9 1.92 0.17 15.2 10 0.23 280 8 0.22 21 Route 2 5 5 693 91.1 2.09 0.22 15.4 11 0.27 376 5 0.07 25 Interstate 495 1 5 391 63.9 2.22 0.17 14.1 12 0.34 316 9 0.04 26 Interstate 495 2 5 490 68.3 2.49 0.21 13.4 13 0.33 362 6 0.1 27 Interstate 495 3 6 779 187 3.05 0.22 18.2 13 0.36 465 15 0.07 44 Interstate 495 4 6 466 99.8 2.63 0.21 17 12 0.36 423 6 0.05 27 Interstate 495 5 5 630 56.2 2.37 0.2 15.9 11 0.28 400 12 0.07 26 Interstate 95 1 5 638 79.5 2.25 0.18 11.9 10 0.25 307 7 0.07 26 Interstate 95 2 6 670 67.9 2.43 0.23 20.1 13 0.3 347 13 0.09 29 Interstate 95 3 6 621 65.1 2.33 0.3 14.7 14 0.37 338 6 0.06 28 Interstate 95 4 8 730 68.4 2.96 0.31 17 15 0.49 386 15 0.07 33 Interstate 95 5 3 592 39 1.84 0.18 11.5 9 0.21 239 4 0.05 22
Tables 16–21

193

Table 20. Distribution of particle sizes and concentrations of 32 elements measured in samples of berm material collected at the edge of the pavement for four highways in Massachusetts, 2005–07.—Continued[Latitude and longitude: In degrees, minutes, and seconds; <, actual value is less than shown; mm, millimeters; ppm, parts per million; %, parts per hundred]

Highway Sample number Phosphorus (%) Lead (ppm) Antimony (ppm) Scandium (ppm) Tin (ppm) Strontium (ppm) Thallium (%) Vanadium (ppm) Tungsten (ppm) Yttrium (ppm) Zinc (ppm) Zirconium (ppm)

Route 119 1 0.04 21 <5 1.7 <10 11.8 0.04 14 <10 5.6 47.5 4

Route 119 2 0.05 20 <5 2.2 <10 13.8 0.06 19 30 7.9 78.3 6.4Route 119 3 0.05 19 <5 2.3 <10 12 0.06 18 <10 8 46.5 3.6Route 119 4 0.04 27 <5 2.3 <10 13.9 0.06 18 <10 8.3 381 7.8Route 119 5 0.04 32 <5 2.5 <10 14.4 0.06 20 <10 8.6 357 8.7Route 2 1 0.04 23 <5 1.8 <10 16.9 0.05 17 <10 6.4 110 6.1

Route 2 2 0.04 24 <5 1.8 <10 24.4 0.06 18 <10 6.6 431 7.1

Route 2 3 0.04 22 <5 1.4 <10 16.2 0.04 15 <10 5.3 176 4.4Route 2 4 0.04 27 <5 1.5 <10 15.4 0.05 17 <10 5.9 115 4.4

Route 2 5 0.05 26 <5 1.9 <10 25.8 0.06 21 <10 6.9 307 6.1Interstate 495 1 0.04 38 <5 1.8 <10 18.8 0.05 24 <10 6.3 1670 5.4Interstate 495 2 0.03 26 <5 1.8 <10 31.1 0.05 23 <10 6.3 172 7.6Interstate 495 3 0.05 56 <5 2.4 <10 22.7 0.07 28 <10 8.7 1350 7.5Interstate 495 4 0.04 48 <5 2.2 <10 22.6 0.07 27 <10 8 1590 6.6Interstate 495 5 0.04 51 <5 1.9 <10 21 0.06 20 <10 6.8 162 6.5Interstate 95 1 0.04 44 <5 2.1 <10 66.3 0.06 27 <10 6.4 458 7.2Interstate 95 2 0.04 40 <5 2.8 <10 205 0.1 33 <10 9.7 91.1 8.4

Interstate 95 3 0.04 27 <5 2.2 <10 35 0.09 34 <10 7.3 485 8.5Interstate 95 4 0.05 22 <5 3.1 <10 43.2 0.12 42 <10 8.8 110 11

Interstate 95 5 0.03 19 <5 1.3 <10 39.1 0.05 22 <10 5.3 98.1 8
194 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds in samples of suspended sediment, 

roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005–07.—Continued

[Values are in micrograms per kilogram ; <, less than the value shown; ≥, greater than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; -R, replicate sample; --, no data; 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]

Highway Sample type Particle-size 

fraction

124-Trichlorobenzene12-Dimethylnaphthalene16-Dimethylnaphthalene1-Methyl-9Hfluorene

Route 119 Suspended sediment < 0.063 mm <2,850 <2,850 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm <1,840 <1,840 <1,840 <1,840

Route 2 Suspended sediment ≥ 0.063 mm <2,010 <2,010 <2,010 <2,010

Interstate 495 Suspended sediment < 0.063 mm <2,580 <2,580 <2,580 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm <5,020 <5,020 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm <3,460 <3,460 <3,460 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm <1,540 <1,540 <1,540 <1,540

Interstate 495 Roadside grasses W -- <200 <200 <200

Interstate 495 Roadside grasses -R W -- <200 <200 <200

Route 119 Pine needles W -- <250 <250 <250

Route 119 Pine needles -R W -- <250 <250 <250

Highway Sample type Particle-size 

fraction

1-Methylphenanthrene 1-Methylpyrene 236-Trimethylnaphthalene26-Dimethylnaphthalene

Route 119 Suspended sediment < 0.063 mm <2,850 <2,850 <2,850 610

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm <1,840 <1,840 813 <1,840

Route 2 Suspended sediment ≥ 0.063 mm <2,010 <2,010 <2,010 <2,010

Interstate 495 Suspended sediment < 0.063 mm <2,580 1,340 <2,580 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm <5,020 <5,020 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm 1,820 <3,460 <3,460 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm <1,540 <1,540 <1,540 <1,540

Interstate 495 Roadside grasses W <200 <200 <200 E63.4

Interstate 495 Roadside grasses -R W <200 <200 <200 E55.1

Route 119 Pine needles W <250 <250 <250 <250

Route 119 Pine needles -R W <250 <250 <250 <250
Tables 16–21 195

Table 21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds in samples of suspended sediment, 

roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005-07.—Continued

[Values are in micrograms per kilogram ; <, Less than the value shown; ≥, greater than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; -R, replicate sample; --, no data; 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]

Highway Sample type Particle-size 

fraction

2-Ethylnaphthalene

2-Fluorobiphenyl,

surrogate

(percent recovery)

2-Methylanthracene

4HCyclopenta[def]

phenanthrene

Route 119 Suspended sediment < 0.063 mm <2,850 79 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm <10,200 76.6 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm <1,840 104 <1,840 <1,840

Route 2 Suspended sediment ≥ 0.063 mm <2,010 91.3 <2,010 <2,010

Interstate 495 Suspended sediment < 0.063 mm <2,580 55.5 <2,580 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm <5,020 86.1 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm <3,460 53.8 <3,460 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm <1,540 83.5 <1,540 <1,540

Interstate 495 Roadside grasses W <200 120.9 <200 --

Interstate 495 Roadside grasses -R W <200 118.2 <200 --

Route 119 Pine needles W <250 105 <250 --

Route 119 Pine needles -R W <250 102.9 <250 --

Highway Sample type Particle-size 

fraction

910-Anthraquinone Fluorene Acenaphthene Acenaphthylene

Route 119 Suspended sediment < 0.063 mm 1950 <2,850 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm 5,420 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm 3,610 <1,840 <1,840 719

Route 2 Suspended sediment ≥ 0.063 mm 1,460 <2,010 <2,010 <2,010

Interstate 495 Suspended sediment < 0.063 mm 3,500 <2,580 <2,580 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm 3,260 <5,020 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm 7,870 <3,460 <3,460 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm 1,340 <1,540 <1,540 <1,540

Interstate 495 Roadside grasses W -- <200 <200 913

Interstate 495 Roadside grasses -R W -- <200 <200 864

Route 119 Pine needles W -- <250 <250 <657

Route 119 Pine needles -R W -- <250 <250 <852
196 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds in samples of suspended sediment, 

roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005-07.—Continued

[Values are in micrograms per kilogram ; <, Less than the value shown; ≥, greater than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; -R, replicate sample; --, no data; 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]

Highway Sample type Particle-size 

fraction Anthracene Benzo[a]-anthracene Benzo[a]pyrene Benzo[b]-fluoranthene

Route 119 Suspended sediment < 0.063 mm <2,850 <2,850 1770 <2,900

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 4,130 <10,200

Route 2 Suspended sediment < 0.063 mm <1,840 2,850 3,260 8,240

Route 2 Suspended sediment ≥ 0.063 mm <2,010 <2,010 1,950 2,930

Interstate 495 Suspended sediment < 0.063 mm <2,580 4,340 4,320 9,090

Interstate 495 Suspended sediment ≥ 0.063 mm <5,020 <5,020 4,660 <6,420

Interstate 95 Suspended sediment < 0.063 mm <3,460 8,090 9,070 22,800

Interstate 95 Suspended sediment ≥ 0.063 mm <1,540 <1,540 1,740 2,860

Interstate 495 Roadside grasses W <200 E68.2 <200 <200

Interstate 495 Roadside grasses -R W <200 E88.6 <200 <200

Route 119 Pine needles W <250 <250 <250 <250

Route 119 Pine needles -R W <250 <250 <250 <250

Highway Sample type Particle-size 

fraction Benzo[e]pyrene Benzo[ghi]-perylene

Benzo[k]-

fluoranthene

Bis(2-ethylhexyl)

phthalate

Route 119 Suspended sediment < 0.063 mm 2,160 <2,850 <2,850 24,300

Route 119 Suspended sediment ≥ 0.063 mm 3,520 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm 5,040 3,880 3,040 74,400

Route 2 Suspended sediment ≥ 0.063 mm 1,890 <2,010 <2,010 21,600

Interstate 495 Suspended sediment < 0.063 mm 5,520 4,020 3,370 23,800

Interstate 495 Suspended sediment ≥ 0.063 mm 4,130 <5,020 <5,020 <17,900

Interstate 95 Suspended sediment < 0.063 mm 13,300 8,950 8,560 106,000

Interstate 95 Suspended sediment ≥ 0.063 mm 1,770 <1,540 <1,540 13,900

Interstate 495 Roadside grasses W <200 <200 <200 --

Interstate 495 Roadside grasses -R W <200 <200 <200 --

Route 119 Pine needles W <250 <250 <250 --

Route 119 Pine needles -R W <250 <250 <250 --
Tables 16–21 197

Table 21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds in samples of suspended sediment, 

roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005-07.—Continued

[Values are in micrograms per kilogram ; <, Less than the value shown; ≥, greater than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; -R, replicate sample; --, no data; 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]

Highway Sample type Particle-size 

fraction Chrysene Dibenzo[ah]-anthracene

DibenzothiopheneDiethyl

phthalate

Route 119 Suspended sediment < 0.063 mm <2,850 <2,850 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm 7,530 <1,840 <1,840 <1,840

Route 2 Suspended sediment ≥ 0.063 mm <2,560 <2,010 <2,010 <2,430

Interstate 495 Suspended sediment < 0.063 mm 7,890 <2,580 <2,580 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm <5,430 <5,020 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm 18,300 <3,460 <3,460 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm 2,540 <1,540 <1,540 <1,540

Interstate 495 Roadside grasses W E44.2 <200 -- --

Interstate 495 Roadside grasses -R W E75.9 <200 -- --

Route 119 Pine needles W <250 <382 -- --

Route 119 Pine needles -R W <250 <378 -- --

Highway Sample type Particle-size 

fraction Fluoranthene Hexachlorobenzene

Indeno[123-cd]-

pyrene Naphthalene

Route 119 Suspended sediment < 0.063 mm <3,260 <2,850 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm 13,700 <1,840 3,530 <1,840

Route 2 Suspended sediment ≥ 0.063 mm 4,660 <2,010 1,440 <2,010

Interstate 495 Suspended sediment < 0.063 mm 14,900 <2,580 3,740 <2,580

Interstate 495 Suspended sediment ≥ 0.063 mm 10,700 <5,020 <5,020 <5,020

Interstate 95 Suspended sediment < 0.063 mm 34,700 <3,460 8,930 <3,460

Interstate 95 Suspended sediment ≥ 0.063 mm 5,190 <1,540 1,240 <1,540

Interstate 495 Roadside grasses W E109 -- <200 E39.0

Interstate 495 Roadside grasses -R W E147 -- <200 E13.9

Route 119 Pine needles W <250 -- <250 <250

Route 119 Pine needles -R W <250 -- <250 <250
198 Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07

Table 21. Concentrations of selected polyaromatic hydrocarbons and phthalate compounds in samples of suspended sediment, 

roadside grasses, and dry pine needles collected from four highways in Massachusetts, 2005-07.—Continued

[Values are in micrograms per kilogram ; <, Less than the value shown; ≥, greater than or equal to the value shown; mm, millimeters in diameter; W, whole 

sample; -R, replicate sample; --, no data; 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]

Highway Sample type Particle-size 

fraction

Nitrobenzene-d5, 

surrogate

(percent recovery)

PentachloroanisolPentachloronitrobenzene Perylene

Route 119 Suspended sediment < 0.063 mm 52.9 <2,850 <2,850 <2,850

Route 119 Suspended sediment ≥ 0.063 mm 61.3 <10,200 <10,200 <10,200

Route 2 Suspended sediment < 0.063 mm 44.9 <1,840 <1,840 1,100

Route 2 Suspended sediment ≥ 0.063 mm 80.3 <2,010 <2,010 789

Interstate 495 Suspended sediment < 0.063 mm 33.9 <2,580 <2,580 1,760

Interstate 495 Suspended sediment ≥ 0.063 mm 70.4 <5,020 <5,020 2,010

Interstate 95 Suspended sediment < 0.063 mm 34.6 <3,460 <3,460 3,090

Interstate 95 Suspended sediment ≥ 0.063 mm 68.8 <1,540 <1,540 696

Interstate 495 Roadside grasses W 78.6 -- -- <200

Interstate 495 Roadside grasses -R W 80.4 -- -- <200

Route 119 Pine needles W 81.6 -- -- <250

Route 119 Pine needles -R W 61.3 -- -- <250

Highway Sample type Particle-size 

fraction Phenanthrene Phenanthridine

P-terphenyl-d14 

surrogate

(percent recovery)

Pyrene

Route 119 Suspended sediment < 0.063 mm <2,850 <2,850 119 <2,920

Route 119 Suspended sediment ≥ 0.063 mm <10,200 <10,200 90.7 <10,200

Route 2 Suspended sediment < 0.063 mm 4,100 766 136 10,400

Route 2 Suspended sediment ≥ 0.063 mm <2,620 <2,010 120 3,820

Interstate 495 Suspended sediment < 0.063 mm 5,120 <2,580 101 12,300

Interstate 495 Suspended sediment ≥ 0.063 mm 6,580 <5,020 124 8,380

Interstate 95 Suspended sediment < 0.063 mm 11,500 <3,460 117 25,900

Interstate 95 Suspended sediment ≥ 0.063 mm 2,740 <1,540 124 3,990

Interstate 495 Roadside grasses W <200 -- 108 E86.0

Interstate 495 Roadside grasses -R W <200 -- 115 E117

Route 119 Pine needles W <250 -- 98.4 <250

Route 119 Pine needles -R W <250 -- 99.7 <250
Prepared by the Pembroke and West Trenton

Publishing Service Center.

For more information concerning this report, contact:

Director

U.S. Geological Survey

Massachusetts-Rhode Island Water Science Center

10 Bearfoot Road

Northborough, MA 01532

dc_ma@usgs.gov

or visit our Web site at:

http://ma.water.usgs.gov
Smith and Granato—Quality of Stormwater Runoff Discharged from Massachusetts Highways, 2005–07—SIR 2009–5269

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