U.S. Department of the Interior

U.S. Geological Survey

Nutrients and Organic Compounds in

Deer Creek and South Branch Plum Creek

in Southwestern Pennsylvania,

April 1996 through September 1998

by Donald R. Williams and Mary E. Clark

Water-Resources Investigations Report 00–4061

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

New Cumberland, Pennsylvania

2001
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only

and does not imply endorsement by the U.S. Government.

For additional information Copies of this report may be

write to: purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

215 Limekiln Road Box 25286

New Cumberland, Pennsylvania 17070 Denver, Colorado 80225-0286

Information regarding the National Water-Quality Assessment (NAWQA) is available on the Internet via

the World Wide Web. You may connect to the NAWQA Home Page using the Universal Resource Locator

(URL) at:

<http://wwwrvares.er.usgs.gov/nawqa>

Information regarding the Allegheny-Monongahela NAWQA Home Page is available on the Internet by

connecting to the NAWQA Home Page using the URL at:

<http://pa.water.usgs.gov/almn>

Information regarding Pennsylvania District Activities is available on the Internet by connecting to the

Pennsylvania District Home Page using the URL at:

<http://pa.water.usgs.gov>

ii
FOREWORD

The mission of the U.S. Geological Survey (USGS) is to access the quantity and quality of the earth

resources of the nation and to provide information that will assist resource managers and policy makers at

Federal, State, and local levels in making sound decisions. Assessment of water-quality conditions and

trends is an important part of this overall mission.

One of the greatest challenges faced by water-resources scientists is acquiring reliable information

that will guide the use and protection of the Nation’s water resources. That challenge is being addressed

by Federal, State, interstate, and local water-resource agencies and by many academic institutions. These

organizations are collecting water-quality data for a host of purposes that include: compliance with

permits and water-supply standards; development of remediation plans for a specific contamination

problem; operational decision on industrial, wastewater, or water-supply facilities; and research on factors

that affect water quality. An additional need for water-quality information is to provide a basis on which

regional- and national-level policy decisions can be based. Wise decisions must be based on sound

information. As a society we need to know whether certain types of water-quality problems are isolated or

ubiquitous, whether there are significant differences in conditions among regions, whether the conditions

are changing over time, and why these conditions change from place to place and over time. The

information can be used to help determine the efficacy of existing water-quality policies and to help

analysts determine the need for and likely consequences of new policies.

To address these needs, the Congress appropriated funds in 1986 for the USGS to begin a pilot

program in seven project areas to develop and refine the National Water-Quality Assessment (NAWQA)

Program. In 1991, the USGS began full implementation of the program. The NAWQA Program builds

upon an existing base of water-quality studies of the USGS, as well as those of other Federal, State, and

local agencies. The objectives of the NAWQA Program are to:

• Describe current water-quality conditions for a large part of the Nation’s freshwater streams, rivers,

and aquifers.

• Describe how water quality is changing over time.

• Improve understanding of the primary natural and human factors that affect water-quality

conditions.

This information will help support the development and evaluation of management, regulatory, and

monitoring decisions by other Federal, State, and local agencies to protect, use, and enhance water

resources.

The goals of the NAWQA Program are being achieved through ongoing and proposed

investigations of 59 of the Nation’s most important river basins and aquifer systems, which are referred to

as study units. These study units are distributed throughout the Nation and cover a diversity of

hydrogeologic settings. More than two-thirds of the Nation’s freshwater use occurs within the 59 study

units and more than two-thirds of the people served by public water-supply system live within their

boundaries.

National synthesis of data analysis, based on aggregation of comparable information obtained from

the study units, is a major component of the program. This effort focuses on selected water-quality topics

using nationally consistent information. Comparative studies will explain differences and similarities in

observed water-quality conditions among study areas and will identify changes and trends and their

causes. The first topics address by the national synthesis are pesticides, nutrients, volatile organic

compounds, and aquatic biology. Discussions on these and other water-quality topics will be published in

periodic summaries of the quality of the Nation’s ground and surface water as the information becomes

available.

This report is an element of the comprehensive body of information developed as part of the

NAWQA Program. The program depends heavily on the advice, cooperation, and information from any

Federal, State, interstate, Tribal, and local agencies and the public. The assistance and suggestions of all are

greatly appreciated.

Robert M. Hirsch

Chief Hydrologist

ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT iii
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT v

CONTENTS

Page

Foreword................................................................................................................................................................................ iii

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

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

Purpose and scope ....................................................................................................................................................... 2

Field and laboratory methods................................................................................................................................................ 4

Quality-control methods and results ........................................................................................................................... 5

Quality-control methods.................................................................................................................................... 5

Quality-control results....................................................................................................................................... 5

Nutrient split replicates ........................................................................................................................... 5

Pesticide split replicates .......................................................................................................................... 5

Pesticide surrogate recoveries ................................................................................................................. 5

Pesticide spikes ....................................................................................................................................... 6

VOC blanks ............................................................................................................................................. 6

Sources of nutrients and organic compounds........................................................................................................................ 6

Sources of nutrients..................................................................................................................................................... 6

Sources of organic compounds.................................................................................................................................... 7

Nutrients in Deer Creek and South Branch Plum Creek....................................................................................................... 8

Concentrations of nutrients ......................................................................................................................................... 9

Seasonality of nutrients ............................................................................................................................................... 9

Pesticides in Deer Creek and South Branch Plum Creek...................................................................................................... 16

Comparison of concentrations and seasonality ........................................................................................................... 16

Maximum pesticide detections.................................................................................................................................... 24

Human-health and aquatic-life criteria........................................................................................................................ 26

Volatile organic compounds in Deer Creek........................................................................................................................... 29

Seasonality of VOCs ................................................................................................................................................... 29

VOCs in stormflow runoff........................................................................................................................................... 29

Human-health criteria for VOCs ................................................................................................................................. 33

Summary and conclusions..................................................................................................................................................... 35

References cited .................................................................................................................................................................... 37

Appendix: Quality-control data............................................................................................................................................. 41

Figure 1. Map showing location of Deer Creek and South Branch Plum Creek Basins and land use within the basins....... 3

2. Boxplots showing concentrations of nutrients in Deer Creek and South Branch Plum Creek from April 1996

through September 1998......................................................................................................................................... 10

3. Graphs showing the relation between nutrient concentrations and streamflow at Deer Creek and

South Branch Plum Creek, April 1996 through September 1998 .......................................................................... 11

4. Graphs showing seasonal variation of nutrient concentrations in Deer Creek and South Branch Plum Creek

from April 1996 through September 1998.............................................................................................................. 13

5. Graph showing nutrient concentrations sampled during a storm in Deer Creek on August 25–26, 1998.............. 14

6. Boxplots showing nutrient concentrations by season (growing and dormant) and flow event

(normal, low, or high) in Deer Creek and South Branch Plum Creek .................................................................... 15

7. Graphs showing measured pesticide concentrations and daily-mean streamflow for Deer Creek and

South Branch Plum Creek, 1997 ............................................................................................................................ 20

8. Graph showing long-term average monthly precipitation at Natrona Lock and Dam 4, Pa., and Indiana, Pa ....... 22

9. Graph showing measured prometon concentrations and streamflow for Deer Creek on August 25–26, 1998...... 25

10. Graph showing measured diazinon concentrations and streamflow for Deer Creek on August 25–26, 1998........ 25

11. Graph showing streamflow hydrograph for Deer Creek near Dorseyville, Pa., from June 1 to June 14, 1997...... 26

ILLUSTRATIONS
vi

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

ILLUSTRATIONS—Continued

Page

12–15. Graphs showing:

12. Seasonal patterns in concentrations of MTBE, benzene, toluene, meta/paraxylene, and napthalene for

samples collected in Deer Creek in 1997................................................................................................................ 32

13. Measured concentrations of methyl chloride, acetone, carbon disulfide, benzene, 1,2,4-trimethyl benzene,

and p-isopropyl toluene from samples collected on August 25-26, 1998............................................................... 33

14. Streamflow hydrograph of Deer Creek prior to and during the storm on December 10, 1997............................... 34

15. Distribution of the percent recovery of selected surrogate compounds using gas chromatography/mass

spectrometry (GC/MS) or high performance liquid chromatography (HPLC) methods of analysis...................... 42

Table 1. Nutrients analyzed in water samples collected from Deer Creek and South Branch Plum Creek from

April 1996 through September 1998....................................................................................................................... 8

2. Correlation between streamflow and nutrient concentrations in Deer Creek and South Branch Plum Creek........ 12

3. Correlation between season and nutrient concentrations in Deer Creek and South Branch Plum Creek............... 12

4. Pesticides and pesticide metabolites analyzed in water samples collected from Deer Creek and South

Branch Plum Creek, January 1997 through August 1998....................................................................................... 17

5. Pesticides detected in the water sample collected on June 13, 1997, in Deer Creek.............................................. 27

6. Guidelines for drinking-water and aquatic-life criteria established for selected pesticides and the maximum

measured concentrations in Deer Creek and South Branch Plum Creek................................................................ 28

7. VOCs analyzed in water samples collected from Deer Creek ................................................................................ 30

8. VOCs detected in Deer Creek samples and a primary use or source of each compound ....................................... 32

9. VOCs detected in Deer Creek on December 10, 1997............................................................................................ 34

10. Comparison of the maximum measured concentrations of VOCs in Deer Creek with the current

U.S. Environmental Protection Agency maximum contaminant level (MCL) ....................................................... 34

11. Concentrations of nutrients in split replicate native water samples at South Branch Plum Creek and

Deer Creek from June 1996 through April 1998 .................................................................................................... 43

12. Concentrations of pesticide compounds analyzed by HPLC and GC/MS methods in filtered split

environmental samples, South Branch Plum Creek, December 12, 1997............................................................... 44

13. Concentrations of pesticides in native water and percent recovery of spiked concentrations at

Deer Creek and South Branch Plum Creek............................................................................................................. 45

14. Concentrations of volatile organic compounds in blank samples collected at Deer Creek, February 2,

April 10, and June 5, 1997, and April 16, 1998...................................................................................................... 47

TABLES
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT vii

Length

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

Area

square mile (mi2) 2.590 square kilometer

acre 0.004047 square kilometer

Volume

cubic foot (ft3) 0.02832 cubic meter

Flow (volume per unit time)

cubic foot per second (ft3/s) 0.02832 cubic meter per second

Concentration in water

milligram per liter (mg/L) 1.0 part per million

microgram per liter (μg/L) 1.0 part per billion

Mass

pound, avoirdupois (lb) 0.4536 kilogram

ton, short (2,000 lb) 0.9072 megagram

Temperature

degree Celsius (°C) °F = 1.8 (°C) + 32 degree Fahrenheit (°F)

Abbreviations

Abbreviation Definition

< less than

2,4-D (2,4-dichlorophenoxy) acetic acid

2,4-DB 4-(2,4-dichlorophenoxy) butyric acid

2,4,5-T (2,4,5-trichlorphenoxy) acetic acid

2,4,5-TP (4,5-trichlorphenoxy) propionic acid

ALMN Allegheny & Monongahela River Basins Study Unit

BDMC 4-Bromo-3,5-dimethylphenyl-n-methylcarbamate

DCPA dimethyltetrachloroterephthalate

DDE dichlorodiphenyldichloroethylene

DDT dichlorodiphenyltrichloroethane

DNOC 4,6-dinitro-o-cresol

E estimated

EPTC S-ethyl dipropylthiocarbamate

GC/MS Gas chromatography/Mass spectrometry

H herbicide

H+ hydrogen ion

HA health advisory

HCH hexachloro-cyclohexane

HPLC high-performance liquid chromatography

I insecticide

CONVERSION FACTORS AND ABBREVIATIONS

Multiply By To obtain
viii

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

All forms of nutrients discussed in this report represent concentrations as either nitrogen or phosphorus. For

example, a nitrate concentration expressed as 10 mg/L refers to a nitrate concentration of 10 mg/L as nitrogen;

dissolved orthophosphate concentration expressed as 10 mg/L refers to a dissolved orthophosphate concentration of 10 mg/L as phosphorus.

LRL laboratory reporting level

MCL maximum contaminant level

MCPA (4-chloro-2-methylphenoxy) acetic acid

MCPB 4-(4-chloro-o-tolyloxy) butyric acid

MDL method detection limit

MTBE methyl tert-butyl ether

NAE National Academy of Engineers

NAS National Academy of Sciences

NAWQA National Water-Quality Assessment Program

NWQL National Water Quality Laboratory

SPE solid-phase extraction

URL Universal Resource Locator

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

VOC volatile organic compound
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 1

ABSTRACT

This report presents results of an analysis of nutrient and pesticide data from two

surface-water sites and volatile organic

compound (VOC) data from one of the sites

that are within the Allegheny and Monongahela River Basins study unit of the National

Water-Quality Assessment Program of the

U.S. Geological Survey. The Deer Creek site

was located in a 27.0 square-mile basin within

the Allegheny River Basin in Allegheny

County. The primary land uses consist of small

urban areas, large areas of residential housing,

and some agricultural land in the upper part of

the basin. The South Branch Plum Creek site

was located in a 33.3 square-mile basin within

the Allegheny River Basin in Indiana County.

The primary land uses throughout this basin

are mostly agriculture and forestland.

Water samples for analysis of nutrients

were collected monthly and during high-flow

events from April 1996 through September

1998. Concentrations of dissolved nitrite,

dissolved ammonia plus organic nitrogen, and

dissolved phosphorus were less than the

method detection limits in more than one-half

of the samples collected. The median concentration of dissolved nitrite plus nitrate in

South Branch Plum Creek was 0.937 mg/L and

0.597 mg/L in Deer Creek. The median concentration of dissolved orthophosphate was

0.01 mg/L in both streams. High loads of

nitrate were measured in both streams from

March to June. Concentrations of dissolved

ammonia nitrogen, dissolved nitrate, and total

phosphorus were lower during the summer

months. Measured concentrations of nitrate

nitrogen in both streams were well below the

U.S. Environmental Protection Agency

(USEPA) maximum contaminant level (MCL)

of 10 mg/L.

Water samples for analysis of pesticides

were collected throughout 1997 in both streams

and during a storm event on August 25–26,

1998 in Deer Creek. Samples were collected

monthly at both sites and more frequently

during the spring and early summer months to

coincide with application of pesticides.

Seventy-eight pesticides and 7 pesticide metabolites were analyzed in 31 samples collected in

Deer Creek and in 18 samples collected in

South Branch Plum Creek. Of the 85 pesticides

and pesticide metabolites analyzed, 25 of the

pesticides were detected at least once in Deer

Creek, and 20 of the pesticides were detected at

least once in South Branch Plum Creek. Atrazine was the most commonly detected pesticide

in both streams. There was a distinct seasonal

pattern of atrazine, simazine, and metolachlor

concentrations measured at both sites.

Prometon was detected in 3 of the

18 samples collected in South Branch Plum

Creek in 1997 and in 28 of the 31 samples

collected in Deer Creek in both 1997 and 1998.

Prometon generally is applied in conjunction

with asphalt paving projects and is commonly

used in residential areas. The highest

measured concentrations of prometon detected

in Deer Creek were in the five storm samples

collected on August 25–26, 1998.

At the Deer Creek site, 9 of the 25 pesticides detected throughout the study were

detected only in the sample collected on June

13, 1997. Those nine pesticides included acifluorfen, bentazon, bromoxynil, dicamba, dichlorprop, fenuron, linuron, MCPA, and neburon.

Nine other pesticides also were detected in that

sample.

NUTRIENTS AND ORGANIC COMPOUNDS IN

DEER CREEK AND SOUTH BRANCH PLUM CREEK

IN SOUTHWESTERN PENNSYLVANIA,

APRIL 1996 THROUGH SEPTEMBER 1998

By Donald R. Williams and Mary E. Clark
2 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

All concentrations of pesticides were well

below established drinking-water guidelines.

The maximum measured concentration of diazinon in Deer Creek (0.097 μg/L) and South

Branch Plum Creek (0.974 μg/L) exceeded the

aquatic life guideline of 0.009 μg/L established

by the National Academy of Sciences/National

Academy of Engineers. The maximum

measured concentration of azinphos-methyl in

South Branch Plum Creek (an estimated value

of 0.033 μg/L) exceeded the chronic aquatic-life

guideline of 0.01 μg/L established by the

USEPA.

Twenty-five samples were collected from

Deer Creek and analyzed for volatile organic

compounds (VOCs). Of 87 VOCs analyzed for,

22 were detected at least once, and 12 were

gasoline-related compounds. Acetone, benzene,

carbon disulfide, meta/paraxylene, methyl chloride, MTBE, p-isopropyl toluene, toluene, and

1,2,4-trimethylbenzene were each detected in

five or more samples. VOCs generally were

detected during the colder winter months and

not frequently during the summer months.

The maximum measured concentrations

of benzene, ethylbenzene, o-dichlorobenzene,

styrene, and toluene were two or more orders of

magnitude lower than the MCLs established by

the USEPA.

INTRODUCTION

The Allegheny and Monongahela River

Basins (ALMN) study unit was one of the

second group of 18 study units in which investigations were begun in 1994 as part of the

U.S. Geological Survey’s (USGS) National

Water-Quality Assessment (NAWQA) Program.

Historical water-quality data were compiled

and analyzed in 1994 and 1995. Intensive

water-quality sampling was conducted in

1996–98 at 10 fixed sites established

throughout the study unit. Five of the fixed

sites are integrator sites that represent waterquality conditions of streams and rivers in

heterogeneous large basins commonly affected

by complex combinations of land-use settings,

point sources, and natural influences. The

remaining five sites are indicator sites that

represent water-quality conditions of streams

in generally smaller basins with relatively

homogeneous land-use settings. The South

Branch Plum Creek and Deer Creek sites are

indicator sites within the ALMN study unit.

Land use in the South Branch Plum Creek

Basin is primarily agriculture and forestland,

and land use in the Deer Creek Basin is a

combination of residential housing, recreational land (golf courses), light industrial,

many paved areas, and some agricultural. The

drainage areas of these two sites are

similar—the South Branch Plum Creek Basin

covers an area of 33.3 mi2 and the Deer Creek

Basin covers an area of 27.0 mi2. The location

of the two basins and land use within each

basin are shown in figure 1.

Although the primary water-quality issue

in the ALMN study unit is the effects of coal

mining and acidic mine drainage from abandoned coal mines on the surface- and groundwater resources, nutrients and pesticides from

agricultural, residential, and commercial areas

and volatile organic compounds (VOCs) from

residential and commercial areas also are

significant concerns. The occurrence and

concentration of nutrients, pesticides, and

VOCs in ground and surface water and their

relation to human and aquatic health criteria

are water-quality issues of national and

regional interest being addressed by the

NAWQA Program.

PURPOSE AND SCOPE

This report presents and compares

concentrations and yields of nutrients and

concentrations of pesticides in Deer Creek, a

stream that drains a predominantly residential

basin, and in South Branch Plum Creek, a

stream that drains a predominantly agricultural basin. VOC concentrations measured in

Deer Creek also are presented. Water samples

were collected at Deer Creek near Dorseyville,

Pa., and South Branch Plum Creek near Five

Points, Pa., for analysis of a broad range of

compounds using a sampling strategy designed

to characterize seasonal variations and a wide

range of streamflow conditions. Effects of residential and agricultural land use on water
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 3

Base from U.S. Geological Survey

1:2,000,000 and 1:100,000 Digital Data

Figure 1. Location of Deer Creek and South Branch Plum Creek Basins and land use within the basins.
4 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

quality were examined by comparing concentrations and yields between the two sites.

Water samples for analysis of nutrients

were collected monthly and during selected

high-flow periods from April 1996 through

September 1998. The nutrients analyzed

included dissolved nitrite plus nitrate,

dissolved ammonia, dissolved ammonia plus

organic nitrogen, total ammonia plus organic

nitrogen, dissolved orthophosphate as phosphorus, dissolved phosphorus, and total phosphorus. For brevity, all forms of nutrients

discussed in this report represent concentrations as either nitrogen or phosphorus. For

example, a nitrate concentration expressed as

10 mg/L refers to a nitrate concentration of

10 mg/L as nitrogen, and a dissolved phosphorus concentration of 10 mg/L refers to a

dissolved phosphorus concentration of 10 mg/L

as phosphorus. Pesticide analyses included

those for 77 compounds and 7 selected pesticide metabolites. In 1997, samples for analysis

of pesticides were collected at least monthly

and more frequently during the months of

March through June. Samples for analysis of

VOCs (87 compounds) were collected at least

monthly and bi-weekly during the colder

months of 1997 at the Deer Creek site. Intermittent VOC samples were collected in 1998 in

Deer Creek. Samples collected throughout a

significant storm event at the Deer Creek site

on August 25–26, 1998, were analyzed for

nutrients, pesticides, VOCs, and major ions.

FIELD AND LABORATORY

METHODS

Streamflow measurements were made in

accordance with standard USGS procedures

(Rantz and others, 1982) and were used to

develop stage-discharge relations. Water

samples for nutrients and pesticide analyses

were collected, processed, and transported

according to methods described by Shelton

(1994). Water samples for VOC analyses were

collected, processed, and transported according

to methods also described by Shelton (1997).

All field water-quality determinations were

performed on the samples by use of protocols

outlined in the National Field Manual for the

Collection of Water-Quality Data (Wilde and

Radtke, 1998). Samples to be shipped for full

laboratory analysis of nutrients and pesticides

were processed in the field in a van outfitted as

a laboratory. Field processing of nutrient and

pesticide samples included sample filtration

and preservation and extraction of filtered

samples for analysis of pesticides through

solid-phase extraction (SPE) cartridges (Zaugg

and others, 1995; Werner and others, 1996).

Samples for VOC analyses were processed at

streamside immediately after sample collection, well away from vehicles, other processing

activities, or other potential contamination

sources. The processed nutrient, pesticide, and

VOC samples were shipped on ice to the USGS

National Water Quality Laboratory (NWQL) in

Arvada, Colo., where the samples were

analyzed. Samples were shipped by priority

mail (next day delivery).

Nutrient samples were analyzed

according to methods described by Fishman

(1993). In October 1997, the NWQL changed

the method detection limit (MDL) for dissolved

ammonia nitrogen from 0.015 mg/L to

0.02 mg/L. In the data used in this report, no

concentrations of dissolved ammonia nitrogen

were between the two MDL values; therefore,

the current MDL of 0.02 is depicted in all

figures except figure 4, as noted. Concentrations of 47 pesticides were determined by

C-18 SPE and capillary-column gas chromatography/mass spectrometry (GC/MS). Concentrations of 39 pesticides were determined by

Carbopak-B SPE and high-performance liquid

chromatography (HPLC). Pesticide samples

were analyzed according to methods described

by Zaugg and others (1995) and Lindley and

others (1996) for GC/MS determinations and

Werner and others (1996) for HPLC determinations. VOC samples were analyzed by use of a

recently approved method for determination of

low concentrations of VOCs in water (Connor

and others, 1998). VOC concentrations were

determined by purge-and-trap isolation and

concentration and capillary-column GC/MS.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 5

QUALITY-CONTROL METHODS AND RESULTS

QUALITY-CONTROL METHODS

In an effort to quantify accuracy, precision, presence of laboratory contamination, and

analytical bias, several quality-control (QC)

samples were collected during the sampling

period. Collection and processing of the sample

may introduce potential sources of variability

and bias that limit the interpretation of the

water-quality data. For nutrient, pesticide, and

VOC data, the NAWQA Program recommends

the use of a series of field-equipment blanks,

replicates, surrogates, and field-matrix spikes

to determine data validity. Descriptions of the

different quality-control samples and collection

procedures are detailed by Mueller and others

(1997) for the nutrient and pesticide data and

by Shelton (1997) for the VOC data. Solutions

of inorganic- or organic-free water that did not

contain the analytes of interest at detectable

levels were used in preparation of a field blank.

A volume of the blank water was poured

through all equipment used in sample collection and then processed in the same manner as

an environmental sample. Field-equipment

blanks are important in establishing the potential bias from contamination of sampling and

processing equipment. Replicate samples were

prepared by dividing the environmental

samples into two equal volumes. Each

subsample was then processed as a separate

sample. Replicates are designed to determine

post-collection precision of values. A surrogate

solution was added to every environmental

pesticide sample. The surrogate solution

contained known concentrations of compounds

not expected to be present in the environment

but to behave similarly to selected target

analytes found in the environment. Data from

the surrogates were used to assess recoveries

and precision of the analytical method for the

targeted analytes. A field-matrix spike

containing the series of organic compounds

used in the analytical schedule was added to an

environmental pesticide replicate. The pesticide sample and the spiked sample were

analyzed. Data from the spiked sample were

used to determine extraction and elution recoveries from the filtered water and to evaluate

the accuracy and precision of the results.

In addition to the processing and submission of quality-control samples, the data were

reviewed routinely for results that seemed

unreasonable on the basis of previous data,

anion/cation balance, and statistics.

QUALITY-CONTROL RESULTS

Nutrient Split Replicates

The results of six split replicate samples

analyzed for nutrients are presented in

table 11 of the appendix. Fifty-eight percent of

the analyses showed no difference between the

split samples. Relative differences between

environmental split samples ranged from 0 to

91 percent. The median relative difference was

0 percent. On the basis of the nutrient QC

results, the conclusion was that nutrient

concentrations in the environmental samples

were of sufficiently high quality to meet the

study’s objectives of detection of nutrient presence or absence, determination of concentration distribution in time and space, and

comparisons to water-quality guidelines.

Pesticide Split Replicates

The results of a split replicate for pesticide compounds analyzed by GC/MS and HPLC

methods are presented in table 12. Ninety-one

percent of pesticide compounds analyzed by

GC/MS analyses showed no difference between

the split samples. For the remaining 9 percent,

or five compounds, the relative difference

ranged from 3 to 33 percent. There was no relative difference between environmental split

samples for HPLC analyses. The surrogate

recoveries varied in each instance. Relative

differences for the surrogate recoveries ranged

from 6 to 9 percent. The difference in recoveries

suggests that most analytes associated with

schedule yield quantitative information.

Pesticide Surrogate Recoveries

The recovery ranges for surrogates added

to pesticide samples are shown in figure 15 at

the back of this report. Recoveries for all surro-
6 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

gates added to the sample for GC/MS analysis

were between 70 and 130 percent. Recoveries

for the surrogate added to the sample for

HPLC analysis were between 60 and

120 percent. Since recoveries for all surrogates

used in each method were above 60 percent,

the results yield quantitative information.

Pesticide Spikes

At each site, a set of split replicates was

spiked for analytes in GC/MS and HPLC

methods. The results of these analyses are

shown in table 13. Eighty-seven percent of the

GC/MS method spike recoveries fell within the

expected recovery range of 60 to 140 percent.

The median for all GC/MS recoveries was

104 percent. Eighty-two percent of the spike

recoveries from the HPLC method fell within

the expected recovery range of 60 to 140 percent. The median for all HPLC method recoveries was 78.5 percent.

VOC Blanks

Four blank VOC samples were prepared

on four different occasions (table 14 of the

appendix). The first blank sample was collected

indoors in the equipment storage area. The

three other samples were field blanks prepared

on site at Deer Creek. The first sample showed

low level detections of nine analytes, indicating

a potential source of VOCs in the storage area.

The sampling equipment was relocated. The

second sample showed detections of three

analytes with estimated values below the

MDL. This indicated the main source of VOCs

had been removed. The third sample showed

detections of two analytes with estimated

values below the MDL. The fourth sample

showed no detections of the VOC analytes.

Samples collected for VOC analysis prior to

March of 1997 may be biased high due to the

source of VOCs in the area where equipment

was stored during that time.

SOURCES OF NUTRIENTS AND

ORGANIC COMPOUNDS

SOURCES OF NUTRIENTS

Nutrients are chemical elements essential to plant and animal nutrition. Nonpoint

nutrient sources are a major contributor to

nutrients in the hydrologic environment. For

example, in the first 20 study units of the

NAWQA Program, it was estimated that about

90 percent of nitrogen and 75 percent of phosphorus originated from nonpoint sources; the

remaining percentages were from point sources

(U.S. Geological Survey, 1999). Combustion of

fuels at high temperatures releases nitrogen

oxide to the atmosphere. This nitrogen oxide

undergoes chemical alterations that produce

hydrogen ions and finally nitrate. In addition

to nitrate, ammonia nitrogen also is present in

precipitation. More than 3 million tons of

nitrogen are deposited in the United States

each year from the atmosphere (U. S. Geological Survey, 1999). The highest deposition rates

of atmospheric nitrogen (greater than 2 tons

per square mile) are in a broad band from the

upper Midwest through the Northeast. This

atmospheric nitrogen is derived either naturally from chemical reactions or from the

combustion of fossil fuels, such as coal and

gasoline. Nitrogen and phosphorus are affected

by chemical and biological processes that

change their form and transfer them to or from

water, soil, biological organisms, and the atmosphere.

Several compounds of nitrogen and phosphorus can be dissolved in water or they can

travel with or attach to sediment particles in

water. Nitrogen and phosphorus are only two of

the many elements, termed nutrients, required

to sustain healthy plant growth. In sufficiently

high concentrations, however, these nutrients

cause excess biological growth that can

adversely affect water quality. Nitrogen is

introduced to the aquatic system in the forms

of nitrate, ammonia, organic nitrogen, or

molecular nitrogen. Rapid transformation

between forms of nitrogen occurs through the

generation of short-lived intermediate forms.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 7

Nitrite is a primary intermediate form in this

process. Although essential for algal and

macrophyte growth, nitrite and nitrate in high

concentrations can be harmful if consumed by

warm-blooded animals. Nitrite reacts with

hemoglobin resulting in oxygen-transport

impairment. Nitrate can be harmful if

converted to nitrite in the gastrointestinal

tract.

Some major nonpoint nutrient sources to

streams include fertilizers applied to cropland

and landscapes, animal wastes, decomposition

of organic matter, sewage effluent, atmospheric

deposition, and dissolution of phosphorusbearing minerals. Nitrogen and phosphorus

are important macronutrients for crop productivity, commonly added to soil as fertilizer.

Although fertilizers have long been considered

one of the major sources of nutrient enriched

waters, animal feedlots are gaining more attention. Increasing livestock populations in

concentrated areas result in a high level of

nitrate contribution to the aquatic system.

Because the nitrate ion is not strongly bound to

soil, it is readily transported through the soil

by water.

Phosphorus is a component of sewage and

some industrial effluents and is always present

in animal metabolic waste (Hem, 1985). Little

phosphorus applied as fertilizer leaches from

the soil because of its transformation to relatively insoluble hydroxyapatite in alkaline

soils.

The primary nutrient source in the

surface water of South Branch Plum Creek

Basin and Deer Creek Basin is fertilizer. Fertilizers are applied to crops in the South Branch

Plum Creek Basin from April through June;

applications vary on the basis of crop type and

weather. Most agricultural fertilizer is applied

prior to or at planting in May and June, and

more is applied to corn than to any other crop.

In the fall, some fertilizers are applied to

pastures and to fields planted to winter wheat.

In the Deer Creek Basin, fertilizers are applied

to landscaped areas—private lawns, recreational areas, and golf courses—during periods

of vigorous plant growth, which generally is

from April through June. Frequently, an early

fall application also is made on lawns.

SOURCES OF ORGANIC COMPOUNDS

Pesticides are typically synthetic organic

compounds introduced into the environment

for many purposes. Pesticides commonly are

used in agriculture, forestry, transportation

(weed control along roadsides and railways),

urban and suburban areas (control of pests in

homes, buildings, gardens and lawns), lakes

and streams (control of aquatic flora and

fauna), and various commercial and industrial

settings. From a National perspective, agricultural pesticide use provides the greatest potential for contamination of surface waters;

nonagricultural uses of pesticides also are

substantial, however, and may be the dominant

source to surface waters in some areas. Pesticide use in residential and urban areas has

undergone major changes over the last several

decades. The growth of suburban areas, the

rise of the lawn-care industry, the development

of new herbicides and insecticides, and the

virtual replacement of organochlorine insecticides with alternative compounds have influenced the amounts and types of pesticides

applied in residential and urban areas. The

atmosphere also can be a significant pesticide

source. Nearly every pesticide investigated has

been detected in air, rain, snow, and fog across

the Nation at different times of the year. Pesticides are widely used in the rural areas in the

South Branch Plum Creek Basin and in the

urban and suburban areas in the Deer Creek

Basin. Pesticide contamination of surface

waters is a critical National issue because of

the potential toxicity of pesticides to aquatic

ecosystems and to humans. However, their

potential toxicity is difficult to evaluate

because of inadequate information on effects of

low-level mixtures, transformation products,

and seasonal exposure. The pesticide data

collected in South Branch Plum Creek and

Deer Creek in the ALMN study unit and in

other NAWQA study units throughout the

United States may provide information to

address some of these unknowns.

VOCs are a class of organic compounds

found in virtually all natural and synthetic

materials. The production of synthetic organic

chemicals (many of which are VOCs) has
8 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

increased by more than an order of magnitude

between 1945 and 1985 (Ashford and Miller,

1991). VOCs are present in many household

items such as deodorants and perfumes,

cleaning and polishing products, paints, adhesives, refrigerants, and ink. VOCs also are used

as general anesthetics, to decaffinate coffee,

and in the production of pharmaceuticals,

pesticides, and fuels. VOCs are present in

combustion exhaust and chlorinated drinking

water. VOCs are released into the environment

during their production, distribution, storage,

handling, and use and can enter the surfacewater system from many point and nonpoint

sources. Some VOC sources in surface waters

include industrial and municipal waste-water

discharges, urban and residential runoff,

precipitation, and accidental spills of crude

petroleum and fuel products. VOCs have chemical and physical properties that allow the

compounds to move freely between water and

air phases of the environment. They generally

have low molecular weights, high vapor pressures, and low-to-medium water solubilities

(Rathbun, 1998). VOCs can be significant environmental contaminants because many are

mobile, persistent, and toxic. The presence of

VOCs in surface water is a matter of increasing

concern, and many VOCs are the focus of

Federal regulations related to water quality

(Leahy and Thompson, 1994). The land uses

throughout the Deer Creek Basin, with its residential and urban areas, shopping malls,

commercial and light industrial areas, and

many miles of roadways and many acres of

paved parking areas, provide a potential

optimum source of VOCs that can accumulate

and eventually be transported into Deer Creek.

NUTRIENTS IN DEER CREEK AND

SOUTH BRANCH PLUM CREEK

Water samples for analysis of nutrients

were collected at the Deer Creek and South

Branch Plum Creek monitoring sites from

April 1996 through September 1998. Samples

were collected monthly and during high-flow

events throughout the sampling period.

Samples were analyzed for eight nutrient

compounds (table 1).

Results of analyses of the water samples

were used to compare nutrient concentrations

in streamflow in a basin in which land use is

predominantly agriculture and forestland

(South Branch Plum Creek) to a mostly

suburban basin (Deer Creek) comprising

mainly residential housing areas, shopping

centers, light industrial companies, golf

courses, and some agricultural land in the

headwaters. The drainage areas above the

monitoring sites were similar in size. Many

Table 1. Nutrients analyzed in water samples collected from Deer Creek and South

Branch Plum Creek from April 1996 through September 1998

PARAMETER

CODE COMPOUND NAME

MINIMUM

REPORTING

LEVEL

(MG/L)

00608 Nitrogen, Ammonia, As N, Dissolved 0.01, 0.02

00613 Nitrogen, Nitrite, As N, Dissolved .01

00623 Nitrogen, Ammonia+organic, As N, Dissolved .20

00625 Nitrogen, Ammonia+organic, As N, Total .20

00631 Nitrogen, Nitrate+nitrite, As N, Dissolved .05

00665 Phosphorus, As P, Total .01

00666 Phosphorus, As P, Dissolved .01

00671 Phosphorus, Orthophosphate, As P, Dissolved .01
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 9

factors, both environmental and human, influence the nutrient concentrations. These factors

include precipitation, runoff, instream

processes, soil types, proximity to the source or

sources, and land use.

In this report, nitrate refers to the sum of

nitrate plus nitrite, as reported by the USGS

laboratory. Nitrite concentrations commonly

were less than the laboratory detection level of

0.01 mg/L, making its contribution to nitrate

plus nitrite negligible. Laboratory and field

data for all samples are published in the

annual data reports for the Ohio River and St.

Lawrence River Basins (Coll and Siwicki,

1996–98).

CONCENTRATIONS OF NUTRIENTS

Most nutrients fall within comparable

ranges for each stream (fig. 2). The range and

median concentrations of total phosphorus

were similar in both streams. Concentrations

of dissolved nitrite, dissolved ammonia plus

organic nitrogen, and dissolved phosphorus

were less than the MDL in more than one-half

the samples collected at each site. Concentrations of the other nutrients sampled were

detected more frequently at levels above the

detection limit. For example, dissolved nitrate

plus nitrite concentrations in South Branch

Plum Creek ranged from <0.05 to 2.58 mg/L;

the median concentration was 0.937 mg/L.

Concentrations in Deer Creek ranged from

<0.05 to 1.44 mg/L; the median concentrations

was 0.597 mg/L. Concentrations of dissolved

ammonia nitrogen in South Branch Plum

Creek ranged from <0.015 to 0.079 mg/L and

the median was 0.03 mg/L; whereas the range

in Deer Creek was <0.015 to 0.138 mg/L and

the median was 0.02 mg/L. Dissolved orthophosphate concentrations ranged from <0.01

to 0.031 mg/L and the median was 0.01 mg/L in

South Branch Plum Creek; the range was

<0.01 to 0.062 mg/L and the median was

0.01 mg/L at Deer Creek. In South Branch

Plum Creek, the maximum concentration of

dissolved nitrate plus nitrite is twice the

maximum concentration measured in Deer

Creek, and the median concentration at South

Branch Plum Creek is over one and one-half

times the median measured in Deer Creek.

Although the maximum concentrations of

dissolved ammonia and dissolved orthophosphate in South Branch Plum Creek are approximately twice the level of those measured at

Deer Creek, the median concentrations of the

two sites are similar.

Concentrations of dissolved ammonia,

dissolved nitrate, dissolved orthophosphate,

and total phosphorus were examined with relation to streamflow (fig. 3). The concentrations

of dissolved nitrate and total phosphorus tend

to increase with increasing streamflow. In

contrast, concentrations of dissolved orthophosphate and dissolved ammonia show no

trend with respect to streamflow, but the

concentrations appear to be higher after storm

events. The correlation coefficients for these

four nutrients are listed in table 2.

SEASONALITY OF NUTRIENTS

Dissolved nitrate concentrations for April

1996 to September 1998 are related to season

(fig. 4). The nitrate concentrations are high

from March to June in South Branch Plum

Creek and Deer Creek. This is most likely

because of higher fertilizer applications to

crops and lawns and lower algal uptake rates

during the growing season, April through

September. After a brief low during the late

summer months, the nitrate concentration

increases. The correlation between nutrient

concentrations and growing season is much

stronger in Deer Creek than in South Branch

Plum Creek (table 3).

The concentrations of dissolved ammonia,

dissolved nitrate, and total phosphorus are

strongly influenced by season (fig. 4). These

constituents tend to have lower concentrations

during the summer months. This is likely

because of lower fertilizer application rates and

runoff rates and increased uptake by algae and

aquatic vegetation during this period. In

contrast, concentrations of dissolved orthophosphate remained nearly constant

throughout the period sampled in South

Branch Plum Creek. In midsummer, 1997,
10 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Figure 2. Concentrations of nutrients in Deer Creek and South Branch Plum Creek from April 1996

through September 1998.

(42)

(39)

0.005 0.1 0.01 0.02 0.05

DISSOLVED NITRITE

(42)

(39)

0.01 10 0.02 0.05 0.1 0.2 0.5 1 2 5

DISSOLVED NITRATE PLUS NITRITE

(42)

(39)

0.01 1 0.02 0.05 0.1 0.2 0.5

DISSOLVED AMMONIA

(42)

(39)

0.1 10 0.2 0.5 1 2 5

Detection limit

25th percentile

Median

75th percentile

interquartile range outside the quartile

Data value less than or equal to 1.5 times the

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

(42) Number of observations

TOTAL AMMONIA PLUS ORGANIC NITROGEN

(42)

(39)

0.1 1 0.2 0.3 0.4 0.5 0.7

DISSOLVED AMMONIA PLUS ORGANIC NITROGEN

(42)

(39)

0.001 10 0.01 0.1 1

TOTAL PHOSPHORUS

(42)

(39)

0.005 0.1 0.01 0.02 0.05

(42)

(39)

0.001 0.1 0.002 0.005 0.01 0.02 0.05

DISSOLVED PHOSPHORUS

DISSOLVED ORTHOPHOSPHATE

Deer Creek

South Branch

Plum Creek

Deer Creek

Deer Creek

Deer Creek

South Branch

Plum Creek

South Branch

Plum Creek

South Branch

Plum Creek

CONCENTRATION, IN MILLIGRAMS PER LITER

EXPLANATION
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 11

Figure 3. The relation between nutrient concentrations and streamflow at Deer Creek and South

Branch Plum Creek, April 1996 through September 1998.

0.1 1 10 100 1,000 10,000 0.01

1

0.02

0.03

0.04

0.05

0.07

0.1

0.2

0.3

0.4

0.5

0.7

DISSOLVED AMMONIA NITROGEN

 CONCENTRATION, IN MILLIGRAMS PER LITER

DEER CREEK

SOUTH BRANCH

 PLUM CREEK

0.1 1 10 100 1,000 10,000

STREAMFLOW, IN CUBIC FEET PER SECOND

0.01

2

0.02

0.05

0.1

0.2

0.5

1

TOTAL PHOSPHORUS CONCENTRATION,

IN MILLIGRAMS PER LITER

0.1 1 10 100 1,000 10,000 0.01

10

0.02

0.05

0.1

0.2

0.5

1

2

5

DISSOLVED NITRATE CONCENTRATION,

IN MILLIGRAMS PER LITER

0.1 1 10 100 1,000 10,000 0.001

0.1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

DISSOLVED ORTHOPHOSPHATE

CONCENTRATION, IN

MILLIGRAMS PER LITER
12 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

orthophosphate concentrations at Deer Creek

begin to show some seasonality. This may be

the result of new residential development in

the Deer Creek Basin. Higher concentrations of

dissolved ammonia, dissolved nitrate, and total

phosphorus seem to be related to fertilizer

application periods to agricultural areas,

lawns, and landscaped areas upstream of the

sampling site in each basin. Storm events

during the growing season may be responsible

for the variability from the seasonal signature

for dissolved nitrate, dissolved ammonia, and

total phosphorus.

Water samples for analysis of nutrients

were collected in Deer Creek throughout a

storm from August 25 to August 26, 1998

(fig. 5). Constituent concentrations generally

follow the stream hydrograph. Dissolved

ammonia concentrations rise only slightly,

peak, and recede in conjunction with the

streamflow. The concentrations of total phosphorus and dissolved orthophosphate rise

quickly but only decrease slightly as the

streamflow recedes. The dissolved nitrate

concentrations remain higher than pre-storm

levels, even as the streamflow returns to

normal conditions. This is possibly due to the

dissolution of the nitrate component of the

fertilizer. The resulting high nitrate solution in

the topsoil drains to a low spot in the field and

then discharges to the stream, rather than

draining through the less permeable topsoil

and discharging to the ground water.

In order to determine how the two basins

respond under similar conditions of streamflow

and season, flow was classified into three

regimes—normal, low, and high flows—and

seasons into growing season and dormant

season (fig. 6). Low flow was defined as those

streamflows below the 10th percentile, and

high flow was defined as those streamflows

above the 90th percentile. The growing

season was defined as the period from April

through September. Statistical significance of

the difference in medians was determined by a

Wilcoxon Signed-Rank Test on season and a

Kruskal-Wallis test on streamflow event with

95-percent confidence level. A p-value equal to

or less than 0.05 was considered statistically

significant. This breakdown shows median

concentrations of dissolved ammonia are

slightly higher during the dormant seasons

and low flows in the South Branch Plum Creek

Basin. In the Deer Creek Basin, median

concentrations of dissolved ammonia do not

vary on the basis of flow event or season. At

both sites, median concentrations of dissolved

nitrate are statistically highest during the

Table 2. Correlation between streamflow and nutrient concentrations in Deer Creek and South Branch Plum

Creek

CONSTITUENT

DEER CREEK SOUTH BRANCH PLUM CREEK

CORRELATION P-VALUE CORRELATION P-VALUE

Dissolved ammonia 0.014 0.930 -0.043 0.795

Dissolved nitrate .579 .000 .375 .019

Dissolved orthophosphate .140 .378 -.082 .621

Total phosphorus .259 .098 .454 .004

Table 3. Correlation between season and nutrient concentrations in Deer Creek and South Branch

Plum Creek

CONSTITUENT

DEER CREEK SOUTH BRANCH PLUM CREEK

CORRELATION P-VALUE CORRELATION P-VALUE

Dissolved ammonia 0.545 0.000 0.214 0.191

Dissolved nitrate .211 .180 .000 1.000

Dissolved orthophosphate .510 .001 .125 .449

Total phosphorus .355 .021 .174 .290
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 13

M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998

0.01

10

0.02

0.05

0.1

0.2

0.5

1

2

5

DISSOLVED NITRATE

 CONCENTRATION,

IN MILLIGRAMS PER LITER

M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998

0.001

0.1

0.002

0.005

0.01

0.02

0.05

DISSOLVED ORTHOPHOSPHATE

CONCENTRATION, IN

MILLIGRAMS PER LITER

M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998

0.001

5

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

TOTAL PHOSPHORUS

 CONCENTRATION,

IN MILLIGRAMS PER LITER

DEER CREEK

SOUTH BRANCH

PLUM CREEK

M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998

DATES

0.1

10,000

1

10

100

1,000

STREAMFLOW, IN

CUBIC FEET PER SECOND

DEER CREEK

SOUTH BRANCH

PLUM CREEK

METHOD DETECTION LIMIT

 (UNTIL OCTOBER 1997)

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

(NOVEMBER 1997 TO PRESENT)

M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998

0.007

0.2

0.01

0.02

0.03

0.04

0.05

0.07

0.1

DISSOLVED AMMONIA

CONCENTRATION, IN

MILLIGRAMS PER LITER

METHOD DETECTION LIMIT

Figure 4. Seasonal variation of nutrient concentrations in Deer Creek and South Branch

Plum Creek from April 1996 through September 1998.
14 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

dormant season and during high flows. During

the growing and dormant seasons and

throughout the flow regime, most concentrations of dissolved orthophosphate in South

Branch Plum Creek were below the MDL of

0.01 mg/L. Only four samples collected during

the growing season and two samples collected

during the dormant season had concentrations

of dissolved orthophosphate higher than the

MDL. In Deer Creek, dissolved orthophosphate

concentrations were higher than the MDL of

0.01 mg/L in more than 50 percent of the

samples collected, and neither season nor flow

event caused statistically significant differences in median concentrations of dissolved

orthophosphate. Total phosphorus concentrations in South Branch Plum Creek were consistently lower than those in Deer Creek Basin.

At both sites, median concentrations of total

phosphorus were slightly but not statistically

higher during the growing season but were

significantly higher during high-flow events

than during normal or low-flow events.

The application of fertilizers and primary

productivity of algae may be the major factors

affecting nutrient concentrations. Neither

stream receives appreciable inflows of industrial or sewage effluent. Although a few small

feedlot operations are present in the South

Branch Plum Creek Basin, animal waste is not

a major contributor to nutrient concentrations.

Total phosphorus concentrations are actually

higher in the Deer Creek Basin, where there

are no feedlot operations. In both streams, the

concentrations of total phosphorus were

highest during storm events in the growing

season, indicating the possible effect of

seasonal application rather than the effects of

sewage discharges or feedlot operations.

0.01

10

0.02

0.03

0.04

0.05

0.07

0.1

0.2

0.3

0.4

0.5

0.7

1

2

3

4

5

7

CONSTITUENT CONCENTRATION, IN MILLIGRAMS PER LITER

0

180

20

40

60

80

100

120

140

160

STREAMFLOW, IN CUBIC FEET PER SECOND

EXPLANATION

STREAMFLOW

DISSOLVED AMMONIA

DISSOLVED NITRATE

TOTAL PHOSPHORUS

DISSOLVED ORTHOPHOSPHATE

1800 2000 2200 2400 0200 0400 0600

AUGUST 25, 1998 AUGUST 26, 1998

1400 1600

Figure 5. Nutrient concentrations sampled during a storm in Deer Creek on August 25–26, 1998.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 15

G D 0.1

1

0.15

0.2

0.25

0.3

0.4

0.5

0.6

0.7

0.8

0.9

DISSOLVED AMMONIA NITROGEN

CONCENTRATION, IN

MILLIGRAMS PER LITER

EXPLANATION

Detection limit

25th percentile

Median

75th percentile

interquartile range outside the quartile

Data value less than or equal to 1.5 times the

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

Deer Creek near Dorseyville, PA

Detection limit

25th percentile

Median

75th percentile

interquartile range outside the quartile

Data value less than or equal to 1.5 times the

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

South Branch Plum Creek at Five Points, PA

N L H 0.01

10

0.02

0.05

0.1

0.2

0.5

1

2

5

G D 0.001

0.1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

DISSOLVED ORTHOPHOSPHATE

CONCENTRATION, IN

MILLIGRAMS PER LITER

N L H 0.001

0.1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

N L H 0.1

1

0.15

0.2

0.25

0.3

0.4

0.5

0.6

0.7

0.8

0.9

G D 0.01

10

0.02

0.05

0.1

0.2

0.5

1

2

5

DISSOLVED NITRATE CONCENTRATION,

 IN MILLIGRAMS PER LITER

N L H

FLOW EVENT

0.001

10

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

G D

SEASON

0.001

10

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

TOTAL PHOSPHORUS CONCENTRATION,

IN MILLIGRAMS PER LITER

FLOW EVENT: N-NORMAL, L-LOW, H-HIGH

SEASON: G-GROWING, D-DORMANT

(10)

(10)

(10)

(10)

(7) (7)

(7) (7)

(7)

(7)

(7)

(7)

(5)

(5)

(5)

(5)

(28) (24)

(28) (24)

(28) (24)

(28) (24)

(14) (14)

(14) (14)

(14) (14)

(14) (14)

(28) (25)

(28) (25)

(28) (25)

(28) (25)

(28) Number of observations

Figure 6. Nutrient concentrations by season (growing and dormant) and flow event (normal, low, or high)

in Deer Creek and South Branch Plum Creek.
16 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

The U.S. Environmental Protection

Agency (USEPA) maximum contaminant level

(MCL) for nitrate-nitrogen is 10 mg/L. The

recommended level for total phosphorus is

0.1 mg/L (U.S. Environmental Protection

Agency, 1986). Concentrations of nitrate and

total phosphorus measured in South Branch

Plum Creek and Deer Creek were well below

these levels.

PESTICIDES IN DEER CREEK AND

SOUTH BRANCH PLUM CREEK

Water samples for analysis of pesticides

were collected at the Deer Creek and South

Branch Plum Creek monitoring sites from

January through December 1997 and during a

storm at the Deer Creek site on August 25–26,

1998. Samples were collected monthly and

more frequently during the spring and early

summer months to coincide with pesticide

application to crops. At the Deer Creek site,

samples were routinely collected once each

month in January, February, and September

through December, twice each month in July

and August, and weekly in March through

June. At the South Branch Plum Creek site,

samples were routinely collected once each

month in January, February, and July through

December and twice each month in March

through June. The samples were collected to

compare pesticide concentrations in streamflow

from a basin in which land use is predominantly agriculture and forestland (South

Branch Plum Creek) to a basin with land use

that is mostly suburban (Deer Creek), mainly

residential housing areas, shopping centers,

light industrial, golf courses, and some agricultural land. Samples were analyzed for 77 pesticides and 7 pesticide metabolites (table 4).

Laboratory analyses and field data for all

samples are published in the annual data

reports for Pennsylvania for the Ohio River

and St. Lawrence River Basins (Coll and

Siwicki, 1997–98).

The pesticides targeted for analyses in

the Deer Creek and South Branch Plum Creek

Basins included herbicides, insecticides, and

one fungicide (table 4). Herbicides are used to

control weeds that compete with crops in agricultural areas and home gardens, to control

broad-leaf weeds on lawns and turf, and to

defoliate utility, railroad, and highway rightsof-way. Herbicides prevent or inhibit the

growth of weeds that compete for nutrients and

moisture needed by crops and are generally

applied before, during, or after planting. Insecticides are used in agricultural, urban, and

suburban areas to control insects and to

protect the crop seeds in storage prior to

planting. Fungicides are used to control the

spread of fungal diseases of plants.

Pesticides detected in 25 percent or more

of the samples collected in Deer Creek in 1997

included atrazine, deethyl atrazine (metabolite), simazine, prometon, metolachlor, and

diazinon. The pesticides detected in 25 percent

or more of the samples collected in South

Branch Plum Creek in 1997 included atrazine,

deethyl atrazine (metabolite), cyanazine,

simazine, metolachlor, and tebuthiuron. All

frequently detected herbicides are used for

weed control and, with the exception of

prometon, are used primarily for weed control

on corn and other grain crops. Non-agricultural

herbicide uses include weed control on golf

courses, public lands, homeowner lawns, and

vegetation-clearing along railways, highways,

and transmission lines. Weed control application frequency for non-agricultural purposes

ranges from routine application by commercial

operations to sporadic application on an asneeded basis by private homeowners.

COMPARISON OF CONCENTRATIONS

AND SEASONALITY

The following comparison of pesticide

data collected at the two sites is limited to the

six most frequently detected pesticides—atrazine, simazine, cyanazine, prometon, metolachlor, and diazinon. Atrazine, cyanazine,

simazine, and prometon are triazine herbicides, and metolachlor is an acetanilide herbicide. Triazine and acetanilide herbicides have

been used in the United States since the

1940’s, and the amounts used in agriculture

have risen dramatically in the last 30 years

(Larson and others, 1997, p. 194). Atrazine,
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 17

Table 4. Pesticides and pesticide metabolites analyzed in water samples collected from Deer Creek and South Branch

Plum Creek, January 1997 through August 1998

[Concentrations are in micrograms per liter; MCL, maximum contaminant level; HA, health advisory; HPLC, high

performance liquid chromatography; GC/MS, gas chromatography/mass spectrometry; - -, no standard or guideline]

PESTICIDE TRADE NAME(S) ANALYSIS

METHOD

METHOD

DETECTION

LIMIT

STANDARD OR

GUIDELINE FOR

DRINKING WATER

(MCL OR HA)

GUIDELINE FOR

AQUATIC LIFE

Herbicides

Acetochlor Acetochlor and many other names GC/MS 0.002 - - - -

Acifluorfen Blazer, Tackle HPLC .035 - - - -

Alachlor Lasso GC/MS .002 12 - -

Atrazine AAtrex GC/MC .001 13 22

Benfluralin Balan, Benefin GC/MC .002 - - - -

Bentazon Basagran HPLC .014 20 - -

Bromacil Bromax 90, Urox B HPLC .035 90 - -

Bromoxynil Buctril, Brominal HPLC .035 - - 25

Butylate Sutan + GC/MS .002 350 - -

Chloramben Amiben HPLC .011 100 - -

Clopyralid Lontrel HPLC .050 - - - -

Cyanazine Bladex GC/MS .004 1 22

2,4-D 2,4-D and many other names HPLC .035 170 33

2,4-DB Butoxone HPLC .035 - - - -

Dacthal, mono acid Dacthal, mono acid HPLC .017 - - - -

DCPA Dacthal GC/MS .002 4,000 - -

Deethyl atrazine metabolite of atrazine GC/MS .002 - - - -

Dicamba Banvel HPLC .035 200 3200

Dichlobenil Casoron HPLC .020 - - 337

Dichlorprop 2,4-DP HPLC .032 - - - -

2,6-Diethylanaline metabolite of alachlor GC/MS .003 - - - -

Dinoseb Basanite and many other names HPLC .035 17

Diuron Diurex and many other names HPLC .020 10 31.6

EPTC Eptam GC/MS .002 - - - -

Ethalfluralin Sonalan GC/MS .004 - - - -

Fenuron Beet-Kleen HPLC .013 - - - -

Fluometuron Cotoran HPLC .035 90 - -

Liuron Lorox GC/MS .002 - - - -

MCPA MCPA and many other names HPLC .050 10 - -

MCPB Thistrol HPLC .035 - - - -

Metolachlor Dual GC/MS .002 100 28

Metribuzin Lexone, Sencor GC/MS .004 200 21

Molinate Ordram GC/MS .004 - - - -

Napropamide Devrinol GC/MS .003 - - - -

Neburon Neburex, Neburon HPLC .015 - - - -

Norflurazon Evital, Zorial HPLC .024 - - - -
18 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Herbicides-Continued

Oryzalin Surflan HPLC 0.019 - - - -

Pebulate Tillam GC/MS .004 - - - -

Pendimethalin Prowl GC/MS .004 - - - -

Picloram Tordon HPLC .050 1500 - -

Prometon Pramitol GC/MS .018 100 - -

Pronamide Kerb GC/MS .003 50 - -

Propachlor Ramrod GC/MS .007 90 - -

Propanil Stampede GC/MS .004 - - - -

Propham IPC HPLC .035 100 - -

Simazine Princep, Aquazine GC/MS .005 1

4 310

2,4,5-T Line Rider and many other names HPLC .035 70 - -

2,4,5-TP Silvex HPLC .021 150 31.4

Tebuthiuron Spike, Graslan GC/MS .010 500 - -

Terbacil Sinbar GC/MS .007 90 - -

Thiobencarb Bolero GC/MS .002 - - - -

Triallate Far-Go GC/MS .001 - - 2.24

Triclopyr Garlon HPLC .050 - - - -

Trifluralin Treflan and several other names GC/MS .002 5 2.10

Insecticides

Aldicarb Temik HPLC .016 13 - -

Aldicarb sulfone metabolite of aldicarb HPLC .016 12 - -

Aldicarb sulfoxide metabolite of aldicarb HPLC .021 14 - -

Azinphos-methyl Guthion GC/MS .001 - - 4.01

Carbaryl Sevin GC/MS .003 700 3.02

Carbofuran Furadan GC/MS .003 140 21.75

Chlorpyrifos Dursban, Lorsban GC/MS .004 20 5.08

p,p’-DDE metabolite of DDT GC/MS .006 - - - -

Diazinon Diazinon and many other names GC/MS .002 .6 3.009

Dieldrin Panoram D-31 GC/MS .001 - - 5.36

Disulfoton Disyston and several other names GC/MS .017 .3 3.05

DNOC Sinox and several other names HPLC .035 - - - -

Esfenvalerate Asana HPLC .019 - - - -

Ethoprop Mocap GC/MS .003 - - - -

Fonofos Dyfonate GC/MS .003 10 - -

alpha-BHC Lindane (impurity) GC/MS .002 - - - -

Lindane gamma-HCH GC/MS .004 1.2 52.0

Table 4. Pesticides and pesticide metabolites analyzed in water samples collected from Deer Creek and South Branch

Plum Creek, January 1997 through August 1998—Continued

[Concentrations are in micrograms per liter; MCL, maximum contaminant level; HA, health advisory; HPLC, high

performance liquid chromatography; GC/MS, gas chromatography/mass spectrometry; - -, no standard or guideline]

PESTICIDE TRADE NAME(S) ANALYSIS

METHOD

METHOD

DETECTION

LIMIT

STANDARD OR

GUIDELINE FOR

DRINKING WATER

(MCL OR HA)

GUIDELINE FOR

AQUATIC LIFE
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 19

cyanazine, and simazine are commonly used

triazines and are used primarily on corn and

other row crops. Atrazine is one of the most

studied and most commonly detected herbicides in the hydrologic environment (Larson

and others, 1999). Prometon is a triazine herbicide used for total vegetative control on industrial sites, on noncrop areas, and in and under

asphalt. The principal mode of action for

triazine herbicides is to disrupt the light reaction of photosynthesis. Metolachlor is one of the

most commonly used acetanilides. It is a selective herbicide used primarily for pre-emergent

and preplant weed control in corn, soybeans,

alfalfa, and sorghum. Diazinon is an organophosphorus insecticide and is one of the more

commonly used insecticides in urban and residential areas throughout the United States.

Common household uses include insect control

on fruits, vegetables, and ornamentals, grub

and nematode control in turf soils, and control

of cockroaches, silverfish, and ants. The variation in concentrations of the six selected pesticides at the two sites during 1997 is shown in

figure 7. The simazine and prometon concentrations that plotted below the MDL are estimated (Zaugg and others, 1995; Werner and

others, 1996). All estimated data are believed

to be reliable detections but with greater than

average uncertainty in quantification.

Land use is an important environmental

factor that affects the magnitude of pesticide

concentrations in streams. Land use is primarily agriculture and forestland in the South

Insecticides-Continued

Malathion Malathion and many other names GC/MS 0.005 200 40.1

Methiocarb Mesurol HPLC .026 - - - -

Methomyl Lannate and several other names HPLC .017 200 - -

Methyl parathion Penncap-M GC/MS .006 2 ‘- -

1-Naphthol metabolite of carbaryl HPLC .007 - - - -

3-OH-carbofuran metabolite of carbofuran HPLC .014 - - - -

Oxamyl Vydate HPLC .018 1200 - -

Parathion Alkron and many other names GC/MS .004 - - 5.065

cis-Permethrin Ambush, Pounce GC/MS .005 - - - -

Phorate Thimet and several other names GC/MS .002 - - - -

Propargite Comite, Omite GC/MS .013 - - - -

Propoxur Baygon HPLC .035 3 - -

Terbufos Counter GC/MS .013 0.9 - -

Fungicide

Chlorothalonil Bravo HPLC .035 - - - -

1Value is the U.S. Environmental Protection Agency (USEPA) maximum contaminant level for drinking water; other values are USEPA lifetime health

advisories for a 70-kilogram adult (Nowell and Resek, 1994).

2Canadian Government aquatic-life guidelines (Canadian Council of Resource and Environment Ministers, 1987; updates 1989–91, 1993).

3National Academy of Sciences and National Academy of Engineering aquatic-life guidelines, 1973 (Nowell and Resek, 1994).

4U.S. Environmental Protection Agency chronic aquatic-life guidelines (Nowell and Resek, 1994).

5U.S. Environmental Protection Agency acute aquatic-life guidelines (Nowell and Resek, 1994).

Table 4. Pesticides and pesticide metabolites analyzed in water samples collected from Deer Creek and South Branch

Plum Creek, January 1997 through August 1998—Continued

[Concentrations are in micrograms per liter; MCL, maximum contaminant level; HA, health advisory; HPLC, high

performance liquid chromatography; GC/MS, gas chromatography/mass spectrometry; - -, no standard or guideline]

PESTICIDE TRADE NAME(S) ANALYSIS

METHOD

METHOD

DETECTION

LIMIT

STANDARD OR

GUIDELINE FOR

DRINKING WATER

(MCL OR HA)

GUIDELINE FOR

AQUATIC LIFE
20 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

J F M A M J J A S O N D

1997

0.0001

10

0.001

0.01

0.1

1

ATRAZINE CONCENTRATION,

IN MICROGRAMS PER LITER

DEER CREEK

SOUTH BRANCH

PLUM CREEK

J F M A M J J A S O N D

1997

0.001

0.1

0.002

0.005

0.01

0.02

0.05

SIMAZINE CONCENTRATION,

IN MICROGRAMS PER LITER

J F M A M J J A S O N D

1997

0.001

1

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

METOLACHLOR CONCENTRATION,

IN MICROGRAMS PER LITER

J F M A M J J A S O N D

1997

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

200

500

1,000

2,000

5,000

DAILY MEAN STREAMFLOW,

IN CUBIC FEET PER SECOND

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

E E E

E E E

E E

E E

Figure 7. Measured pesticide concentrations and daily-mean streamflow for Deer Creek and South

Branch Plum Creek, 1997.

[E, estimated value; all values plotted below the method detection limit are estimated values.]
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 21

J F M A M J J A S O N D

1997

0.001

0.1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

PROMETON CONCENTRATION,

IN MICROGRAMS PER LITER

J F M A M J J A S O N D

1997

0.001

0.1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

CYANAZINE CONCENTRATION,

IN MICROGRAMS PER LITER

J F M A M J J A S O N D

1997

0.0015

0.15

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

0.1

DIAZINON CONCENTRATION,

IN MICROGRAMS PER LITER

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

METHOD DETECTION LIMIT

Figure 7. Measured pesticide concentrations and daily-mean streamflow for Deer Creek

and South Branch Plum Creek, 1997—Continued.
22 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Branch Plum Creek Basin and residential,

urban, forestland, and some agriculture in the

Deer Creek Basin. Two other factors, in addition to land use, that can have a significant

effect on pesticide concentrations in streams

include climate and the period of pesticide

application. The growing season in these two

basins generally extends from April through

September and covers periods of normally high

and low streamflow conditions. Most of the

annual precipitation falls during the early

months of the growing season (April through

June), which coincides with the time of year

when pesticide application for agricultural

purposes and for residential lawn care are

generally at a peak. Long-term average

monthly precipitation amounts from National

Weather Service rain gage data (National

Oceanic and Atmospheric Administration,

1997) for Indiana, Pa., which is near the South

Branch Plum Creek Basin, and for Natrona

Lock and Dam 4 on the Allegheny River, which

is near the Deer Creek Basin, are shown in

figure 8. These data show a significant amount

of precipitation in both basins during the early

months of the growing season.

Land use, seasonality, and streamflow

affect the concentrations of the six selected

pesticides sampled in the two streams (fig. 7).

Four of the pesticides shown in figure 7 (atrazine, simazine, cyanazine, and metolachlor) are

herbicides that are generally applied to corn

and other agricultural row crops. Other than

the extremely high-flow samples collected on

May 26, 1997, it appears that concentrations of

atrazine, simazine, and metolachlor were more

seasonal dependent than flow dependent.

Concentrations of these three constituents

were not statistically related to streamflow but

were statistically related to season. Atrazine

was the most commonly detected pesticide in

both streams; it was detected in all 18 samples

collected from South Branch Plum Creek and

in 24 of the 26 samples collected from Deer

Creek in 1997. Measured concentrations of

atrazine and cyanazine always were higher in

South Branch Plum Creek than in Deer Creek.

Paired concentrations of atrazine and cyanaJan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

1997

2.0

5.0

2.5

3.0

3.5

4.0

4.5

AVERAGE MONTHLY PRECIPITATION, IN INCHES

Natrona Lock

and Dam 4, Pa.

(72 years of record)

Indiana, Pa.

(100 years of record)

Figure 8. Long-term average monthly precipitation at Natrona Lock and Dam 4, Pa., and

Indiana, Pa.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 23

zine produced statistically significant differences in concentrations between the two

streams when used in the Wilcoxon SignedRank Test. The p-value was 0.005 for atrazine

and 0.0035 for cyanazine. The higher concentrations measured in South Branch Plum

Creek were attributed to the greater amount of

agriculture in that basin. The highest

measured concentrations for atrazine,

simazine, cyanazine, and metolachlor at both

sites were in the high-flow sample collected on

May 26, 1997. That high-flow event coincided

with the end of the planting season for corn

and came at a time shortly after most row-crop

pesticides had been applied in both basins.

Studies in other basins in the United States

indicate similar annual patterns in stream

pesticide concentrations. Crawford (1995)

reported that atrazine concentrations in the

White River at Hazelton, Ind., from 1991

through 1995, were highest during the

planting period, and the highest concentrations

typically were during the first one or two

periods of runoff after application.

On a few isolated occasions, concentrations of simazine and metolachlor were either

equal to or slightly greater in Deer Creek than

concentrations measured in South Branch

Plum Creek. Simazine is used generally for

agricultural purposes, but it also is used extensively on fruits and vegetables and for weed

control in residential areas, along railways,

highways, and transmission lines. This may

explain why simazine concentrations were

sometimes higher in Deer Creek. Voss and

others (1999) reported that atrazine and

simazine were found at more than 60 percent

of the study sites in 10 urban watersheds in

King County, Wash., indicating that these two

pesticides were being applied in areas such as

rights-of-way, parks, and recreational areas.

During a 2-month period from early March

until late April, concentrations of metolachlor

in Deer Creek were slightly higher than

concentrations in South Branch Plum Creek.

Differences in concentrations of metolachlor

and simazine between the two sites were not

statistically significant on the basis of results

of the Wilcoxon Signed-Rank Test.

The pattern of decreasing concentrations

of atrazine, simazine, and metolachlor at both

sites after the peak concentration measured on

May 26 implies a reduction in the supply available in the following months. Most corn is

planted in May, and most pesticides are applied

at planting time. Some of the pesticides are

flushed from the land surface to the streams

during subsequent surface-runoff periods, but

the degradation of the compounds with time is

the more significant cause of the depletion of

pesticides on the soils. An example of the

depletion of pesticide availability can be seen

from the two samples collected in the South

Branch Plum Creek in November 1997. The

routine monthly sample was collected on

November 4 at 0930; the streamflow was

28 ft3/s. Four days later on November 8 at

1330, a high-flow sample was collected at a

streamflow of 1,440 ft3/s, but the concentration

of atrazine only increased from 0.025 to

0.041 μg/L. Simazine concentration remained

the same, metolachlor concentration increased

from 0.008 to 0.025 μg/L, cyanazine concentration decreased, and prometon and diazinon

concentrations were not detected in either

sample. The peak streamflow of record for the

South Branch Plum Creek site for the 2.5-year

study period was 1,620 ft3/s at 1000 on

November 8, just 3.5 hours prior to when the

high-flow sample was collected.

In recent large-scale studies by the

USGS, prometon has been the most commonly

detected herbicide in surface water and ground

water in urban areas and the third and fourth

most commonly detected herbicide in ground

water and surface water, respectively, in agricultural areas. It also has been detected in rain

(Capel and others, 1999). Prometon has a

variety of uses and applications. It is used as a

pre-emergent herbicide to control vegetation on

bare ground around buildings, fences, and

along rights-of-way and is commonly applied to

the land surface below layers of asphalt on

roads, parking lots, and trails. Prometon was

detected in only 3 of the 18 samples collected in

South Branch Plum Creek but was detected in

23 of the 26 samples collected in Deer Creek.

All three detections in South Branch Plum

Creek and 21 of the 23 detections in Deer
24 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Creek were estimated values at low concentrations (fig. 7). Prometon generally is applied at

any time of the year depending on its intended

uses, and its use in conjunction with asphalt

paving generally provides a direct transport

route to surface-water resources in residential

areas. As the asphalt wears and cracks,

prometon in and under it becomes exposed to

rain water and can find its way to surfacewater drainage. The Deer Creek Basin has a

high density of paved areas that could be the

major source of prometon measured at the

monitoring site. Concentrations of prometon

measured in Deer Creek showed no apparent

trends (fig. 7). The highest concentrations were

measured in the five samples collected during a

storm on August 25–26, 1998 (fig. 9). The first

sample collected during the storm had a

concentration of 0.355 μg/L and the four subsequent samples had progressively decreasing

concentrations. Prior to the storm on August

25, the last appreciable amount of precipitation

in the Deer Creek Basin was on July 23, 1998.

Paving during the period between July 23 and

August 25 and the accompanying application of

prometon may have been a major source of this

pesticide in the five high-flow samples collected

during August 25–26, 1998.

The insecticide diazinon is more

commonly applied for home and garden use

than for agricultural use. Majewski and Capel

(1995) report that outdoor applications of

diazinon by homeowners in 1990 were about

30 times greater than the amount used for

agricultural purposes. Crawford (1996) found

significantly higher concentrations of diazinon

in streams in urban areas of the White River

Basin, Ind., than in agricultural areas. Diazinon concentrations were detected in only 2 of

the 18 samples collected from the South

Branch Plum Creek in 1997, in 7 of the

26 samples collected from Deer Creek in 1997,

and in all 5 samples collected from Deer Creek

during August 25–26, 1998. Insecticides are

generally applied at times when pest control is

necessary, unlike the seasonal application

method used for herbicides applied to agricultural crops and to lawns and gardens. Detections of diazinon from samples collected from

Deer Creek in 1997 showed no seasonal

pattern (fig. 7); however, five of the seven detections were in samples collected shortly after a

peak in streamflow due to overland runoff

throughout the basin. Diazinon also was

detected in all five of the storm runoff samples

collected on August 25–26, 1998. The peak

concentration, 0.051 μg/L, was measured in the

last two samples collected on the streamflow

recession (fig. 10).

Cyanazine is applied almost exclusively

to corn for weed control. It is more biodegradable and has less residual carryover than atrazine or metolachlor. Cyanazine was present in

10 of 11 samples collected in the South Branch

Plum Creek from mid-May through December

but was not detected in any of the 7 samples

collected from January through early May

(fig. 7). It was detected in only 2 of the 28

samples collected in Deer Creek, and those

samples were collected in late May on the

recession of two significant rises in the stream.

The sample collected in Deer Creek on May 26

was collected on the recession of the maximum

streamflow recorded for the period of record at

the site. Cyanazine was not detected in any of

the five streamflow samples collected from

Deer Creek on August 25–26, 1998.

MAXIMUM PESTICIDE DETECTIONS

Of the 85 pesticides and pesticide metabolites sampled in Deer Creek and South Branch

Plum Creek, 25 of the pesticides were detected

at least once in Deer Creek, and 20 of the pesticides were detected at least once in South

Branch Plum Creek. At the Deer Creek site, 9

of the 25 pesticides detected during the study

were detected only in the June 13, 1997,

sample. Nine other pesticides also were

detected in that sample. Prior to June 13, 1997,

streamflow in Deer Creek had been on a

gradual recession (fig. 11) from a moderate

peak flow of 111 ft3/s at 1100 on June 2, 1997.

Streamflow gradually receded to a flow of

15 ft3/s late in the day of June 12. Precipitation

and surface runoff on June 12 and 13 resulted

in a peak flow of 97 ft3/s at 0830 on June 13.

The sample for pesticide analysis collected

from Deer Creek was at 1045 on June 13 at a

flow rate of 76 ft3/s. From late in the day on
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 25

0

180

20

40

60

80

100

120

140

160

STREAMFLOW, IN CUBIC FEET PER SECOND

0.01

1

0.02

0.03

0.04

0.05

0.07

0.1

0.2

0.3

0.4

0.5

0.7

PROMETON CONCENTRATION, IN MICROGRAMS PER LITER

STREAMFLOW

PROMETON

Aug 24, 1998 Aug 25, 1998 Aug 26, 1998

METHOD DETECTION LIMIT

Figure 9. Measured prometon concentrations and streamflow for Deer Creek on

August 25–26, 1998.

0

160

20

40

60

80

100

120

140

STREAMFLOW, IN CUBIC FEET PER SECOND

0.001

0.08

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

DIAZINON CONCENTRATION, IN MICROGRAMS PER LITER

STREAMFLOW

DIAZINON

AUG 24, 1998 AUG 25, 1998 AUG 26, 1998

METHOD DETECTION LIMIT

Figure 10. Measured diazinon concentrations and streamflow for Deer Creek on

August 25–26, 1998.
26 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

June 2 to late in the day on June 12, there was

no appreciable surface runoff throughout the

Deer Creek Basin. Early June is an optimum

period for the widespread application of pesticides from individual homeowners, from professional applicators, from utility companies, and

from the farmers in the headwater areas of the

basin. Most likely, a number of pesticide

compounds were applied in the basin prior to

the storm on June 12 and 13. When surface

runoff occurred on June 12 and 13, many of

those pesticides were flushed from the land

surface into the stream and were detected in

the stream sample. The 18 pesticides detected

in the stream sample collected on June 13 and

the 9 pesticides that were detected only in that

sample are shown in table 5. Four of those nine

pesticides (acifluorfen, bentazon, bromoxynil,

and MCPA) are classified as selective-postemergent type pesticides, pesticides expected

to be present in mid-June during postemergent

weed growth. Three of the 18 pesticides

detected in the June 13 sample (dicamba,

MCPA, and 2,4-D) are herbicides commonly

used by commercial lawn companies

During the period of pesticide application,

the greatest number of pesticide compounds

usually are detected during the first flush of

runoff to streams regardless of the magnitude

of streamflow. The samples collected in Deer

Creek on May 26, 1997, represented the

highest streamflow sampled for pesticides in

Deer Creek in 1997. The streamflow in Deer

Creek for the May 26 sample was 149 ft3/s,

almost twice the amount of streamflow of the

sample collected on June 13 (76 ft3/s). However,

10 pesticides were detected in the May 26

sample compared to 17 pesticides detected in

the June 13 sample. The May 26 sample was

collected about 40 hours after the initial rise in

streamflow and the June 13 sample was

collected about 12 hours after the initial rise in

streamflow.

HUMAN-HEALTH AND AQUATIC-LIFE CRITERIA

Of the 85 pesticides and pesticide metabolites analyzed in samples collected from Deer

Creek and South Branch Plum Creek, humanhealth criteria were established by the USEPA

(1999) for 39 of the pesticides and 2 of the

pesticide metabolites. The criteria include

maximum contaminant levels (MCLs) and

health advisories (HAs). Pesticide MCLs and

HAs are based on chronic long-term exposure;

therefore, pesticide concentrations in individual samples that exceed these criteria may

not necessarily indicate a violation of a

1 2 3 4 5 6 7 8 9 10 11 12 13 14

June 1997

0

140

20

40

60

80

100

120

STREAMFLOW, IN CUBIC FEET PER SECOND

Pesticide Sample

June 13, 1997

Streamflow = 76 ft3/s

Figure 11. Streamflow hydrograph for Deer Creek near Dorseyville, Pa., from June 1 to 14, 1997.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 27

standard. The MCL is the maximum permissible annual average concentration of a

contaminant in water that is delivered to any

use of a public water system. The HA is an

advisory guideline for drinking-water exposure over a 70-year lifetime, considering

noncarcinogenic adverse health effects. More

detail on these types of criteria, their derivation, and their underlying assumptions is

provided in Nowell and Resek (1994). Although

Deer Creek and South Branch Plum Creek are

not used as a drinking-water supply, the MCLs

and HAs are offered as a point of reference for

comparison to actual concentrations measured

in the two streams.

Water-quality guidelines also have been

established by the USEPA and the National

Academy of Sciences and National Academy of

Engineering (NAS/NAE) for the protection of

aquatic life (Nowell and Resek, 1994). The

USEPA guidelines include acute and chronic

criteria. Acute criteria are based on exposure

levels of as much as 1.0 hour, and chronic

criteria are based on an exposure time of 1 to

4 days. Aquatic guidelines set by the Canadian

Government (Canadian Council of Resource

and Environmental Ministers, 1987) are

commonly used for pesticides that have not yet

been assigned criteria by the USEPA or

NAS/NAE. Guidelines for drinking water

and/or aquatic life for only those pesticides that

were detected in Deer Creek or South Branch

Plum Creek and the maximum measured

concentrations of those pesticides detected are

listed in table 6. The guidelines for drinking

water and aquatic life for all 85 pesticides and

pesticide metabolites analyzed for in this study

are presented in table 4. Four pesticides that

have MCLs for drinking water were detected in

either Deer Creek or South Branch Plum

Creek, but the maximum concentrations of

those pesticides were well below the MCLs

established by the USEPA. The maximum

measured concentration of atrazine in South

Branch Plum Creek (1.63 μg/L) was the only

pesticide concentration that approached the

drinking-water guideline of 3.0 μg/L. The

concentrations of two insecticides measured in

Table 5. Pesticides detected in the water sample collected on June 13, 1997, in Deer Creek

[Concentrations are in micrograms per liter; E, estimated value]

PESTICIDE CONCENTRATION USE

Herbicides

Acifluorfen1

1Pesticide detected only in the June 13, 1997 sample.

0.040 selective, postemergence

Atrazine .203 selective, season-long weed control

Deethyl atrazine E .005 degradation product of atrazine

Bentazon1 E .050 selective, postemergence

Bromoxynil1 E .070 selective contact, postemergence

Dicamba1 E .120 broadleaf weed control

Dichlorprop1 .040 brush control on rights-of-way

Diuron .180 young broadleaf and grass weeds

Fenuron1 .050 woody plants, deep rooted perennial weeds

Linuron1 E .020 selective weed control

MCPA1 .100 selective, postemergence

Metolachlor .033 selective, preemergence

Neburon1 .040 selective weed control

Prometon .025 nonselective

Simazine .010 selective, annual grasses and broadleaf weeds

2,4-D 1.16 broadleaf weeds

Insecticides

Carbaryl E .022 broad spectrum insecticide

Diazinon .096 commonly used insecticide
28 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

South Branch Plum Creek and one insecticide

measured in Deer Creek slightly exceeded the

guidelines established for aquatic life. The

maximum measured concentration of diazinon

in Deer Creek (0.097 μg/L) and South Branch

Plum Creek (0.094 μg/L) exceeded the aquaticlife guideline of 0.009 μg/L established by the

NAS/NAE. The maximum measured concentration of azinphos-methyl in South Branch Plum

Creek (E 0.033 μg/L) exceeded the chronic

aquatic-life guideline of 0.01 μg/L established

by the USEPA. In summarizing pesticide data

from 65 sites available from the first phase of

the NAWQA Program, Gilliom and others

(1999) found that aquatic-life criteria established by the USEPA, Canada, or the International Joint Commission for the Great Lakes

were exceeded by at least one compound in one

or more samples for about two-thirds of the

streams sampled−−most commonly by the

herbicides atrazine or cyanazine or the insecticides azinphos-methyl, chlorpyrifos, diazinon,

or malathion.

Table 6. Guidelines for drinking-water and aquatic-life criteria established for selected pesticides

and the maximum measured concentrations in Deer Creek and South Branch Plum Creek

[Concentrations are in micrograms per liter; H, herbicide; I, insecticide; MCL, maximum contaminant

level; HA, Health Advisory; __, no standard or guideline; - -, all measured values were less than

the method detection limit; E, estimated value]

PESTICIDE (TYPE)

STANDARD OR

GUIDELINE FOR

DRINKING WATER

(MCL OR HA)

GUIDELINE FOR

AQUATIC LIFE

MAXIMUM MEASURED

CONCENTRATIONS

DEER CREEK SOUTH BRANCH

PLUM CREEK

Alachlor (H) 12 __ - - 0.008

Atrazine (H) 13 22 0.222 1.630

Azinphos-methyl (I) __ 2.01 - - E .033

Bentazon (H) 20 __ E .050 - -

Bromoxynil (H) __ 35 E .070 - -

Carbaryl (I) 700 __ E .613 .010

Chlorpyrifos (I) 20 4.08 E .003 .010

Cyanazine (H) 1 22 .014 .058

DCPA (H) 4,000 __ E .001 E .002

Diazinon (I) 0.6 5.009 .097 .094

Dicamba (H) 200 5200 E .120 - -

2,4-D (H) 170 53 1.160 1.010

Diuron (H) 10 51.6 .400 - -

MCPA (H) 10 __ .100 .940

Metolachlor (H) 100 28 .099 .851

Prometon (H) 100 __ .355 E .004

Propachlor (H) 90 __ - - .064

Simazine (H) 14 510 .092 .088

Tebuthiuron (H) 500 E .004 .021

Terbacil (H) 90 __ E .009 - -

Trifluralin (H) 5 2.10 E .002 - -

1Value is the U.S. Environmental Protection Agency (USEPA) maximum contaminant level for drinking

water; other values are USEPA lifetime health advisories for a 70-kilogram adult (Nowell and Resek, 1994). 2U.S. Environmental Protection Agency chronic aquatic-life guidelines (Nowell and Resek, 1994).

3Canadian Government aquatic-life guidelines (Canadian Council of Resource and Environment Ministers,

1987; updates 1989-91, 1993). 4U.S. Environmental Protection Agency acute aquatic-life guidelines (Nowell and Resek, 1994).

5National Academy of Sciences and National Academy of Engineering aquatic-life guidelines, 1973 (Nowell

and Resek, 1994).
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 29

VOLATILE ORGANIC COMPOUNDS

IN DEER CREEK

Water samples for analysis of VOCs were

collected in Deer Creek near Dorseyville, Pa.,

from January 1997 through August 1998; most

samples were collected during 1997. In 1997,

samples were collected once each month in

January, April–June, August, and September.

Samples were collected twice each month in

the remaining months. Two samples were

collected on July 28, 1997—the first sample at

noon was at low flow, and the second at 3 p.m.,

shortly after a thunderstorm. One sample was

collected on March 10, 1998, shortly after a

winter frontal system had passed through the

area, and one sample was collected on April 16,

1998, during high flow, shortly after a thunderstorm. Five VOC samples were collected during

a storm on August 25–26, 1998. During the

period January 1997 through August 1998, a

total of 25 VOC samples were collected from

Deer Creek, and samples were analyzed for

87 VOCs (table 7). Of those 87 VOCs, 22 were

detected at least once in the 25 samples

collected. The nine VOCs that were detected in

20 percent (5 samples) or more of the samples

included acetone, benzene, carbon disulfide,

meta/paraxylene, methyl chloride, MTBE,

p-isopropyl toluene, toluene, and 1,2,4-trimethylbenzene. Each VOC that was detected, the

total number of detections as well as the

number of detections in the five storm samples

collected on August 25–26, 1998, and the

primary use of each compound are listed in

table 8. Twelve of the 22 VOCs detected were

gasoline-related compounds. Ninety-three

percent of all detections of VOCs were below

the laboratory reporting level (LRL). The LRL

is the reporting level for reliable quantification

of the VOCs analyzed. The LRL for all

compounds ranged from 0.03 to 5.0 μg/L.

Although confirmed detections of the presence

of VOCs below the LRL values commonly

occurred, accurate quantification in these

instances could not be guaranteed, and the

values were considered estimates.

SEASONALITY OF VOCS

Temperature is a significant factor

affecting the occurrence of VOCs. The concentrations of VOCs in water can increase by a

factor of about three to seven when water

temperatures decrease from 25°C to 5°C (Lopes

and Bender, 1998). These higher levels of VOCs

could be caused by an increase in partitioning

of VOCs from air into precipitation or slower

volatilization from water during cold months.

Delzer and others (1996) found that MTBE and

benzene were detected more frequently during

the winter than the summer. MTBE, benzene,

toluene, meta/paraxylene,

and napthalene showed evidence of seasonality

in samples collected in Deer Creek. Of the

18 VOC samples collected in 1997 in Deer

Creek, MTBE was detected six times in

samples collected in January, February, March,

November, and December, and benzene was

detected six times in samples collected in

February, October, November, and December.

MTBE also was detected in one of the five

storm samples collected on August 25–26,

1998. Benzene was detected in the May 29,

1997, sample and all five storm samples

collected on August 25–26, 1998. The May 29,

1997, sample and the August 25–26, 1998,

samples were all associated with storm runoff.

The seasonal variability in concentrations of

MTBE, benzene, toluene, meta/paraxylene, and

naphthalene for samples collected in 1997 is

shown in figure 12. All five compounds were

detected in February, November, and

December, and none of the compounds were

detected in July through September.

VOCS IN STORMFLOW RUNOFF

VOCs can accumulate on impervious

surfaces and can be flushed into the receiving

stream during storms. The flushing effect can

result in high concentrations in the initial

runoff from a storm and relatively lower

concentrations during the remainder of the

runoff period. Fourteen VOCs were detected in

at least one of the five samples collected during

the storm on August 25–26, 1998, and six of

those VOCs were detected in the samples
30 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Table 7. VOCs analyzed in water samples collected from Deer Creek

[All values are in micrograms per liter; LRL, laboratory reporting level; CAS number,

Chemical Abstract Services Number]

PARAMETER CODE CAS NUMBER PARAMETER NAME LRL

77562 630-20-6 1,1,1,2-Tetrachloroethane 0.044

34506 71-55-6 1,1,1-Trichloroethane .032

34516 79-34-5 1,1,2,2-Tetrachloroethane .13

34511 79-00-5 1,1,2-Trichloroethane .064

77652 76-13-1 Freon 113 .032

34496 75-34-3 1,1-Dichloroethane .066

34501 75-35-4 1,1-Dichloroethylene .044

77168 563-58-6 1,1-Dichloropropene .026

49999 488-23-3 1,2,3,4-Tetramethylbenzene .23

50000 527-53-7 Isodurene .24

77613 87-61-6 1,2,3-Trichlorobenzene .27

77443 96-18-4 1,2,3-Trichloropropane .16

77221 526-73-8 1,2,3-Trimethylbenzene .12

34551 120-82-1 1,2,4-Trichlorobenzene .19

77222 95-63-6 1,2,4-Trimethylbenzene .056

82625 96-12-8 1,2-Dibromo-3-chloropropane .21

77651 106-93-4 1,2-Dibromoethane .036

34536 95-50-1 O-Dichlorobenzene .048

32103 107-06-2 1,2-Dichloroethane .13

34541 78-87-5 1,2-Dichloropropane .068

77226 108-67-8 1,3,5-Trimethylbenzene .044

34566 541-73-1 1,3-Dichlorobenzene .054

77173 142-28-9 1,3-Dichloropropane .12

34571 106-46-7 1,4-Dichlorobenzene .05

77170 594-20-7 2,2-Dichloropropane .078

81595 78-93-3 Methyl ethyl ketone 1.6

77275 95-49-8 2-Chlorotoluene .042

77103 591-78-6 2-Hexanone .7

78109 107-05-1 3-Chloropropene .2

77277 106-43-4 p-chlorotoluene .056

77356 99-87-6 p-isopropyl toluene .11

78133 108-10-1 Methyl isobutyl ketone .37

81552 67-64-1 Acetone 5

34210 107-02-8 Acrolein 2.0

34215 107-13-1 Acrylonitrile 1.2

34030 71-43-2 Benzene .1

81555 108-86-1 Bromobenzene .036

77297 74-97-5 Bromochloromethane .048

32101 75-27-4 Bromodichloromethane .048

50002 593-60-2 Bromoethene .1

32104 75-25-2 Bromoform .1

34413 74-83-9 Methyl bromide .15

77342 104-51-8 Butylbenzene .19

77041 75-15-0 Carbon disulfide .37

34301 108-90-7 Chlorobenzene .028
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 31

34311 75-00-3 Chloroethane 0.12

32106 67-66-3 Chloroform .052

34418 74-87-3 Methyl chloride .25

77093 156-59-2 cis-1,2-Dichloroethylene .038

34704 10061-01-5 cis-1,3-Dichloropropene .09

32105 124-48-1 Dibromochloromethane .18

30217 74-95-3 Dibromomethane .05

34668 75-71-8 Dichlorodifluoromethane .14

34423 75-09-2 Methylene chloride .38

81576 60-29-7 Ethyl ether .17

81577 108-20-3 Diisopropyl ether .098

73570 97-63-2 Ethyl methacrylate .28

50004 637-92-3 Ethyl tert-butyl ether .054

34371 100-41-4 Ethylbenzene .03

39702 87-68-3 Hexachlorobutadiene .14

34396 67-72-1 Hexachloroethane .36

77223 98-82-8 Isopropylbenzene .032

85795 108-38-3 (m)

106-42-3 (p)

m- and p-Xylene .06

49991 96-33-3 Methyl acrylate 1.4

81593 126-98-7 Methyl acrylonitrile .57

77424 74-88-4 Methyl iodide .21

81597 80-62-6 Methyl methacrylate .35

34696 91-20-3 Naphthalene .25

77224 103-65-1 n-Propylbenzene .042

77220 611-14-3 o-Ethyl toluene .1

77135 95-47-6 o-Xylene .06

77350 135-98-8 sec-Butylbenzene .048

77128 100-42-5 Styrene .042

78032 1634-04-4 MTBE .17

77353 98-06-6 tert-Butylbenzene .1

50005 994-05-8 tert-Pentyl methyl ether .11

34475 127-18-4 Tetrachloroethylene .1

32102 56-23-5 Carbon tetrachloride .088

81607 109-99-9 Tetrahydrofuran 9

34010 108-88-3 Toluene .05

34546 156-60-5 trans-1,2-Dichloroethylene .032

34699 10061-02-6 trans-1,3-Dichloropropene .13

73547 110-57-6 trans-1,4-Dichloro-2-butene .7

39180 79-01-6 Trichloroethylene .038

34488 75-69-4 Trichlorofluoromethane .09

39175 75-01-4 Vinyl chloride .11

77057 108-05-4 Vinyl acetate 5.0

Table 7. VOCs analyzed in water samples collected from Deer Creek—Continued

[All values are in micrograms per liter; LRL, laboratory reporting level; CAS number,

Chemical Abstract Services Number]

PARAMETER CODE CAS NUMBER PARAMETER NAME LRL
32 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Table 8. VOCs detected in Deer Creek samples and a primary use or source of each compound

VOC TOTAL NUMBER

OF DETECTIONS

NUMBER OF

DETECTIONS

IN STORM

SAMPLES ON

AUGUST 25–

26, 1998

USE OR SOURCE

Benzene 13 5 Gasoline component

Toluene 13 0 Gasoline component

Acetone 11 5 Solvent and reagent

Methyl chloride 8 4 Refrigerant, catalyst carrier in manufacture of butyl rubber

Carbon disulfide 7 3 Solvent for oils, fats, and rubber and in paint remover

MTBE 7 1 Gasoline component, octane enhancer

P- isopropyl toluene 7 5 Gasoline component

Meta/paraxylene 7 2 Used in insecticides and to synthesize vitamins and pharmaceuticals

1,2,4-trimethyl benzene 6 3 Gasoline component

Naphthalene 4 0 Used in organic synthesis

o-Xylene 4 1 Gasoline component

Ethylbenzene 3 0 Gasoline component

Chloroform 3 2 Solvent

Methylethyl ketone 3 1 Solvent

Styrene 2 1 Used to make plastics

o-Ethyl toluene 2 0 Gasoline component

1,4-Dichlorobenzene 2 1 Gasoline component

O-dichlorobenzene 1 1 Gasoline component

1,3,5-Trimethylbenzene 1 0 Gasoline component

n-Propylbenzene 1 0 Gasoline component

Methyl isobutyl ketone 1 0 Solvent

Freon 113 1 0 Refrigerant, solvent

0.001

1

0.002

0.003

0.004

0.005

0.007

0.01

0.02

0.03

0.04

0.05

0.07

0.1

0.2

0.3

0.4

0.5

0.7

CONCENTRATION, IN MICROGRAMS PER LITER

MTBE

BENZENE

TOLUENE

META/PARAXYLENE

NAPTHALENE

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

Figure 12. Seasonal patterns in concentrations of MTBE, benzene, toluene, meta/paraxylene, and napthalene for

samples collected in Deer Creek in 1997.

[When two concentrations for a VOC were detected in 1 month, the higher detected concentration was plotted.]
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 33

collected on the rise, peak, and recession of the

storm hydrograph (fig. 13). The maximum

measured concentrations of acetone, carbon

disulfide, benzene, 1,2,4-trimethylbenzene, and

p-isopropyltoluene were in the sample collected

on the rise in the hydrograph at 1715. The

maximum concentration for methyl chloride

was in the sample collected near the peak in

streamflow at 1850. The smallest concentrations of all six compounds were measured in

the last or the next to the last sample collected

during the runoff period. As mentioned previously, no measurable amount of precipitation

had fallen 1 month prior to the storm. During

this storm, measured concentrations of VOCs

were highest in the initial flush and smallest in

the last or next to the last sample showing a

flush-off effect (fig. 13).

Fourteen VOCs detected in a sample

collected on December 10, 1997 (table 9), may

have resulted from a flush of accumulated

VOCs from impervious surfaces, in addition to

a low water temperature of 5.0°C. Ten of the

14 VOCs were gasoline-related compounds.

The sample was collected at 1140 at a streamflow of 127 ft3/s (fig. 14). The peak streamflow

was 137 ft3/s and occurred 35 minutes later. No

significant runoff occurred during the 10 days

prior to when the sample was collected.

HUMAN-HEALTH CRITERIA FOR VOCS

The USEPA (1999) has established MCLs

for drinking water for 20 of the 87 VOCs

analyzed. Only 5 of the 20 compounds were

detected in samples collected from Deer Creek.

Although the water from Deer Creek is not

used as a drinking-water supply, the MCLs for

the five compounds are given in table 10 as a

point of reference for comparison to the

maximum measured concentrations. The

maximum measured concentrations of all five

compounds were two or more orders of magnitude lower than the established MCLs.

0

180

20

40

60

80

100

120

140

160

STREAMFLOW, IN CUBIC FEET PER SECOND

0.001

10

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

CONCENTRATION, IN MICROGRAMS PER LITER

STREAMFLOW

METHYL CHLORIDE

ACETONE

CARBON DISULFIDE

BENZENE

1,2,4-TRIMETHYLBENZENE

P-ISOPROPYLTOLUENE

August 25, 1998 August 26, 1998

(4) TOTAL NUMBER

OF DETECTIONS

(3) (6) (6) (6) (4)

1330

1715

1850

21000710

Figure 13. Measured concentrations of methyl chloride, acetone, carbon disulfide, benzene, 1,2,4-trimethyl

benzene, and p-isopropyl toluene from samples collected on August 25–26, 1998.
34 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

30 1 2 3 4 5 6 7 8 9 10 11 12 13

December

1997

0

160

20

40

60

80

100

120

140

STREAMFLOW, IN CUBIC FEET PER SECOND

VOC sample

December 10, 1997

Streamflow = 127 ft3/s

NOV 1997 DEC 1997

Figure 14. Streamflow hydrograph of Deer Creek prior to and during the storm on December 10, 1997.

Table 9. VOCs detected in Deer Creek on

December 10, 1997

[Concentrations are in micrograms per liter; E,

estimated value]

VOC CONCENTRATION

Carbon disulfide E 0.032

MTBE1

1Gasoline related compounds.

E .089

Benzene1 E .028

Methyl isobutyl ketone E .260

Toluene1 .115

Ethylbenzene1 E .020

Meta/paraxylene E .084

o-Xylene1 E .046

Styrene E .009

n-Propybenzene1 E .010

1,3,5-Trimethylbenzene1 E .020

o-Ethyltoluene1 E .016

1,2,4-Trimethylbenzene1 E .070

1,4-Dichlorobenzene1 E .029

Table 10. Comparison of the maximum measured

concentrations of VOCs in Deer Creek with the current

U.S. Environmental Protection Agency maximum

contaminant level (MCL)

[Concentrations are in micrograms per liter; E, estimated

value]

VOC

MAXIMUM

MEASURED

CONCENTRATION

USEPA MCL

CONCENTRATION

Benzene E 0.049 5

Ethylbenzene E .02 700

O-dichlorobenzene E .01 600

Styrene E .009 100

Toluene .115 1,000
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 35

SUMMARY AND CONCLUSIONS

The Allegheny and Monongahela River

Basins (ALMN) study unit was one of the

second group of 18 study units in which investigations were begun in 1994 as part of the U.S.

Geological Survey (USGS) National WaterQuality Assessment (NAWQA) Program. Intensive water-quality sampling was conducted in

1996–98 at 10 fixed sites established

throughout the study unit. The South Branch

Plum Creek and Deer Creek are two of the

fixed sites referred to as “indicator sites” that

represent water-quality conditions of streams

in generally smaller basins with relatively

homogeneous land-use settings. The land use

in the South Branch Plum Creek Basin is

primarily agriculture and forestland. The land

use in the Deer Creek Basin is a combination of

residential housing, light industrial, numerous

shopping malls, many acres of paved parking

and highways, and some agriculture.

Water samples for analysis of nutrients

were collected monthly and during selected

storms from April 1996 through September

1998. The nutrients analyzed included

dissolved nitrite plus nitrate, dissolved

ammonia, dissolved ammonia plus organic

nitrogen, total ammonia plus organic nitrogen,

dissolved orthophosphorus, dissolved phosphorus, and total phosphorus. Pesticide

samples were collected at least monthly and

more frequently during the months of March

through June at both sites. The pesticide analyses included 78 pesticides and 7 selected

pesticide metabolites. Of the 85 pesticides and

pesticide metabolites, 54 were herbicides, 30

were insecticides, and 1 was a fungicide.

Samples for analysis of 87 volatile organic

compounds (VOCs) were collected at least

monthly and twice each month during the

colder months of 1997 at the Deer Creek site.

In 1998, VOC samples were collected intermittently at Deer Creek. Samples were collected

throughout a significant storm event at Deer

Creek on August 25–26, 1998, and analyzed for

nutrients, pesticides, VOCs, and major ions.

Most nutrient concentrations in samples

collected from the two sites were within comparable ranges. Concentrations of dissolved

nitrite, dissolved ammonia plus organic

nitrogen, and dissolved phosphorus were less

than the method detection limit (MDL) in more

than half the samples collected at both sites.

The median concentrations of dissolved nitrite

plus nitrate in South Branch Plum Creek and

Deer Creek were 0.937 and 0.597 mg/L, respectively. The median concentrations of dissolved

ammonia nitrogen were similar in South

Branch Plum Creek and Deer Creek at 0.03

and 0.02 mg/L, respectively, and the median

concentration of dissolved orthophosphate was

0.01 mg/L in both streams. Concentrations of

dissolved nitrate and total phosphorus tended

to increase with increasing flows in both

streams, whereas concentrations of dissolved

orthophosphate and dissolved ammonia

remained fairly constant regardless of the

magnitude of streamflow. Nutrient data

collected throughout a storm on August 25–26,

1998, show that concentrations of dissolved

ammonia, dissolved orthophosphate, and total

phosphorus rise, peak, and recede in conjunction with the streamflow. Dissolved nitrate

concentrations rise quickly but only decrease

slightly as the streamflow recedes. Nitrate

concentrations remain much higher than prestorm levels even as the streamflow returns to

normal levels. The U.S. Environmental Protection Agency (USEPA) MCL for nitrate in

drinking water is 10 mg/L, and concentrations

measured in both streams were well below that

level.

Of the 85 pesticides and pesticide metabolites analyzed for in samples collected from

both streams, 25 of those pesticides were

detected at least once in Deer Creek and 20 of

those pesticides were detected at least once in

South Branch Plum Creek. Pesticides detected

in 25 percent or more of the samples collected

in Deer Creek in 1997 included atrazine,

deethyl atrazine (metabolite), simazine,

prometon, metolachlor, and diazinon. The

pesticides detected in 25 percent or more of the

samples collected in South Branch Plum Creek
36 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

in 1997 included atrazine, deethyl atrazine

(metabolite), cyanazine, simazine, metolachlor,

and tebuthiuron. Atrazine was the most

commonly detected pesticide in both streams.

It was detected in all 18 samples collected in

South Branch Plum Creek and in 24 of the

26 samples collected in Deer Creek in 1997.

Atrazine concentrations were always higher in

South Branch Plum Creek than those

measured in Deer Creek. This was attributed

to the much greater amount of agriculture in

the South Branch Plum Creek Basin. Simazine

is used generally for agricultural purposes, but

it also is used extensively for weed control in

residential areas, along railways, highways,

and transmission lines. This may explain why

simazine concentrations were sometimes

higher in Deer Creek than in the agriculturedominated South Branch Plum Creek.

Atrazine, simazine, and metolachlor

concentrations measured at both sites showed

a distinct seasonal pattern. Peak concentrations were measured for these three pesticides

at both sites on May 26, 1997. After May 26,

concentrations decreased throughout the

remainder of the year. These pesticides are

generally applied from April through June,

which coincides with high precipitation

periods.

Prometon was detected in only 3 of the

18 samples collected in the South Branch Plum

Creek in 1997 but was detected in 28 of the

31 samples collected in Deer Creek in 1997 and

1998. Prometon is generally applied anytime of

the year depending on its intended uses, and

its use in conjunction with asphalt paving

provides a source to surface water in highly

residential areas such as in the Deer Creek

Basin. Trends in prometon concentrations

measured in Deer Creek were not apparent,

however, the concentrations measured in the

five storm samples collected on August 25–26,

1998, were some of the highest concentrations

measured. The highest measured concentration of 0.355 μg/L was in the first storm sample

collected, which was about 4 hours after the

initial increase in streamflow. The four subsequent samples had progressively decreasing

concentrations. The storm followed a dry

period of over 30 days during which extensive

asphalt paving probably took place throughout

the basin. Asphalt paving is generally accompanied by the application of prometon, which

may have been a major source of the prometon

detected in the five storm samples collected on

August 25–26, 1998.

The insecticide diazinon is more

commonly applied for home and garden use

than for agricultural purposes and may be the

reason for the higher number of detections in

Deer Creek than in South Branch Plum Creek.

Diazinon detections from samples collected in

Deer Creek showed no seasonal pattern,

however, five of the seven detections in 1997

were in samples collected on a streamflow

recession, shortly after a peak in streamflow

when overland runoff was a significant factor

throughout the basin. Diazinon also was

detected in all five storm samples collected in

Deer Creek on August 25–26, 1998.

At the Deer Creek site, 9 of the 25 pesticides detected throughout the study were

detected only in the sample collected on June

13, 1997. Those nine pesticides included acifluorfen, bentazon, bromoxynil, dicamba, dichlorprop, fenuron, linuron, MCPA, and neburon.

Nine other pesticides also were detected in that

sample. The sample was collected on the

streamflow recession, about 2 hours after the

streamflow had peaked. Prior to that peak flow,

no appreciable precipitation was recorded

throughout the basin for about a 10-day period

from June 2–12. Throughout that 10-day

period, which is an optimum time for widespread pesticide application from individual

homeowners, professional applicators, utility

companies, and farmers, a large diversity of

pesticides probably were applied throughout

the basin. When surface runoff occurred on

June 12th and 13th, many of those pesticides

were washed from the land surface into the

stream and were detected in the stream

sample. The pesticide sample collected in Deer

Creek on June 13, 1997, indicates that the

period of pesticide application throughout a

basin has a significant effect on pesticides

detected in streamflow runoff.

Drinking water guidelines were available

for seven pesticides detected in Deer Creek and

South Branch Plum Creek, but the maximum
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 37

measured concentration of those seven pesticides were well below the MCLs established by

the USEPA. The maximum measured concentration of atrazine (1.63 μg/L) in South Branch

Plum Creek was the only pesticide concentration that approached the drinking-water guideline of 3.0 μg/L.

The maximum measured concentration of

diazinon in Deer Creek (0.097 μg/L) and South

Branch Plum Creek (0.097 μg/L) exceeded the

aquatic-life guideline of 0.009 μg/L established

by the NAS/NAE. The maximum measured

concentration of azinphos-methyl in South

Branch Plum Creek (an estimated value of

0.033 μg/L) exceeded the chronic aquatic-life

guideline of 0.01 μg/L established by the

USEPA.

Of the 87 VOCs analyzed in Deer Creek

in 1997 and 1998, 22 were detected at least

once. Twelve of the 22 VOCs detected were

gasoline-related compounds. The nine VOCs

that were detected in five or more of

the samples included acetone, benzene, carbon

disulfide, meta/paraxylene, methyl chloride,

MTBE, p-isopropyl toluene, toluene, and

1,2,4-trimethylbenzene. Benzene and toluene

were detected in more than 50 percent of the

samples collected.

The detection of VOCs appears related to

temperature; five were detected during the cold

winter months but not at all during the

summer months. Concentrations of MTBE,

benzene, toluene, metaparaxylene, and napthalene were detected in February, November, and

December of 1997 but were not detected in any

samples collected in July though September

1997. Of the 18 VOC samples collected in 1997

in Deer Creek, MTBE was detected six times in

samples collected in January, February, March,

November, and December, and benzene was

detected six times in samples collected in

February, October, November, and December.

Five VOCs were detected in all five samples

collected during a storm on August 25–26,

1998. The maximum concentrations of acetone,

carbon disulfide, benzene, 1,2,4-trimethylbenzene, and p-isopropyltoluene were measured in

the sample collected during the first flush

produced by the storm. The smallest concentrations of the five VOCs were measured in the

last or next to the last sample collected, long

after the initial flush had depleted the build-up

supply of VOCs. The large number of VOCs

detected in the sample collected on December

10, 1997, may have resulted from a flush of

accumulated VOCs from the impervious

surfaces throughout the basin in addition to a

low water temperature of 5.0°C. Fourteen

VOCs were detected, and 10 of the 14 were

gasoline-related compounds. The streamflow in

Deer Creek when the sample was collected

was 127 ft3/s, and the peak streamflow for

that storm occurred just 35 minutes later at

137 ft3/s. No significant runoff had occurred

throughout the basin for at least 10 days prior

to when the sample was collected.

Five VOCs detected in samples collected

in Deer Creek had USEPA drinking-water

standards. The maximum measured concentrations of ethylbenzene, o-dichlorobenzene,

styrene, and toluene were more than three

orders of magnitude lower than the MCL

established by the USEPA. The maximum

measured concentration of benzene was more

than two orders of magnitude lower than the

MCL.

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Capel, P.D., Spexet, A.H., and Larson, S.J., 1999, Occurrence and behavior of the herbicide prometon in the

hydrologic system: Environmental Science and Technology, v. 33, no. 5, p. 674–680.

Coll, M.B., Jr., and Siwicki, R.W., 1996–98, Water

resources data for Pennsylvania, v. 3., Ohio River and

St. Lawrence River Basins: U.S. Geological Survey

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Connor, B.F., Rose, D.L., Noriega, M.C., Murtagh, L.K.,

and Abney, S.R., 1998, Methods of analysis by the

U.S. Geological Survey National Water Quality

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Crawford, C.G., 1995, Occurrence of pesticides in the

White River, Indiana, 1991–95: U.S. Geological

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Delzer, G.C., Zogorski, J.S., Lopes, T.J., and Bosshart, R.L.,

1996, Occurrence of the gasoline oxygenate MTBE

and BTEX compounds in urban stormwater in the

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

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Survey Open-File Report 93–125, 217 p.

Gilliom, R.J., Alley, W.M., and Gurtz, M.E., 1995, Design

of the National Water-Quality Assessment Program—

Occurrence and distribution of water-quality conditions: U.S. Geological Survey Circular 1112, 33 p.

Gilliom, R.J., Barbash, J.E., Kolpin, D.W., and Larson, S.J.,

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characteristics of natural water (3d ed.): U.S. Geological Survey Water-Supply Paper 2254, 263 p.

Larson, S.J., Gilliom, R.J., and Capel, P.D., 1999, Pesticides

in streams of the United States—Initial results from the

National Water-Quality Assessment Program: U.S.

Geological Survey Water-Resources Investigations

Report 98–4222, 92 p.

Larson, S.J., Capel, P.D, and Majewski, M.S., 1997, Pesticides in surface waters—Distributions, trends, and

governing factors: Chelsea, Mich., Ann Arbor Press,

Inc., 373 p.

Leahy, P.P., and Thompson, T.H., 1994, U.S. Geological

Survey National Water-Quality Assessment Program:

U.S. Geological Survey Open-File Report 94–70, 4 p.

Lindley, C.E., Stewart, J.T., and Sandstrom, M.W., 1996,

Determination of low concentrations of acetochlor in

water by automatic solid-phase extraction and gas

chromatography with mass-selective detection: Journal

of AOAC International, v. 1, no. 79, p. 962–966.

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volatile organic compounds in urban areas—Relative

importance of land surfaces and air: Environmental

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Majewski, M.S., and Capel, P.D., 1995, Pesticides in the

atmosphere—distribution, trends, and governing

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hydrologic system: Chelsea Mich., Ann Arbor Press,

Inc., v. 1, 214 p.

Mueller, D.K., and Helsel, D.R., 1996, Nutrients in the

Nation’s waters—Too much of a good thing?: U.S.

Geological Survey Circular 1136, 24 p.

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Climatological data annual summary, Pennsylvania,

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aquatic organisms—Application to water-quality

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Rantz, S.E. and others, 1982, Measurement and computation of streamflow—Volume 1, Measurement of stage,

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p. 285–631.

Rathbun, R.E., 1998, Transport, behavior, and fate of volatile organic compounds in streams: U.S. Geological

Survey Professional Paper 1589, 151 p.

Shelton, L.R., 1994, Field guide for collecting and

processing stream-water samples for the National

Water-Quality Assessment Program: U.S. Geological

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National Water-Quality Assessment Program: U.S.

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U.S. Geological Survey, 1999, The quality of our Nation’s

waters—Nutrients and pesticides: U.S. Geological

Survey Circular 1225, 82 p.

Voss, F.D., Embrey, S.S., and Ebbert, J.C., 1999, Pesticides

detected in urban streams during rainstorms and relations to retail sales of pesticides in King County, Washington: U.S. Geological Survey Fact Sheet 097–99,

4 p.
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 39

Werner, S.L., Burkhardt, M.R., and DeRusseau, S.N., 1996,

Methods of analysis by the U.S. Geological Survey

National Water-Quality Laboratory—Determination of

pesticides in water by Carbopak-B solid-phase extraction and high-performance liquid chromatography:

U.S. Geological Survey Open-File Report 96–216,

42 p.

Wilde, F.D., and Radtke, D.B., eds., 1998, National field

manual for the collection of water-quality data: U.S.

Geological Survey Techniques of Water-Resources

Investigations, book 9, chap. A6, variously paged.

Zaugg, S.D., Sandstrom, M.W., Smith, S.G., and Fehlberg,

K.M., 1995, Methods of analysis by the U.S. Geological Survey National Water-Quality Laboratory—

Determination of pesticides in water by C-18 solidphase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion

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

95–181, 49 p.
40 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 41

APPENDIX:

QUALITY-CONTROL DATA
42 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Figure 15. Distribution of the percent recovery of selected surrogate compounds

using gas chromatography/mass spectrometry (GC/MS) or high performance

liquid chromatography (HPLC) methods of analysis.

(49) (49) (49) (49)

Diazinon Terbuthylazine alpha HCH BDMC

SURROGATES

50

200

60

70

80

90

100

150

RECOVERY, IN PERCENT

EXPLANATION

25th percentile

Median

75th percentile

interquartile range outside the quartile

Data value less than or equal to 1.5 times the

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

(49) Number of observations

GC/MS Surrogate

25th percentile

Median

75th percentile

interquartile range outside the quartile

Data value less than or equal to 1.5 times the

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

(49) Number of observations

HPLC Surrogate
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 43

Table 11. Concentrations of nutrients in split replicate native water samples at South Branch Plum Creek and Deer Creek

from June 1996 through April 1998

[Concentrations are in milligrams per liter; <, less than}

SOUTH BRANCH PLUM CREEK AT FIVE POINTS, PA. DEER CREEK NEAR

DORSEYVILLE, PA.

CONSTITUENT 6/17/96 12/12/96 12/9/97 2/27/98 4/24/98 7/9/97

SAMPLE

1

SAMPLE

2

SAMPLE

1

SAMPLE

2

SAMPLE

1

SAMPLE

2

SAMPLE

1

SAMPLE

2

SAMPLE

1

SAMPLE

2

SAMPLE

1

SAMPLE

2

Dissolved

orthophosphate

<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.013 <0.01 <0.01 <0.01 <0.01

Dissolved

nitrate+

nitrite

.66 <.05 1.3 1.3 1.18 1.17 1.12 <.05 2.58 .845 .063 <.05

Dissolved

ammonia

.04 .03 .06 .05 <.02 <.02 .036 <.02 .054 .041 <.015 <.015

Dissolved

phosphorus

<.01 <.01 .02 <.01 <.01 <.01 <.01 <.01 .016 <.01 <.01 <.01

Dissolved

ammonia +

organic

nitrogen

<.2 <.2 <.2 <.2 <.1 <.1 <.1 <.1 .26 <.1 <.2 <.2

Total

ammonia +

organic

nitrogen

<.2 <.2 .6 .3 <.1 <.1 .11 <.1 <.1 <.1 .3 <.2

Total phosphorus.03 <.01 .12 .07 <.01 <.01 <.01 <.01 <.01 <.01 .023 <.01
44 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Table 12. Concentrations of pesticide compounds analyzed by HPLC and GC/MS methods in filtered split

environmental samples, South Branch Plum Creek, December 12, 1997

[Concentrations in micrograms per liter; <, less than}

PESTICIDE

COMPOUNDSANALYZED

BY HPLC

SAMPLE

1

SAMPLE

2

PESTICIDE

COMPOUNDSANALYZED

BY GC/MS

SAMPLE

1

SAMPLE

2

PESTICIDE

COMPOUNDS ANALYZED

BY GC/MS

SAMPLE

1

SAMPLE

2

2,4,5-T <0.035 <0.035 Acetochlor <0.002 <0.002 Terbacil <0.007 <0.007

2,4,5-D <.15 <.015 Alachlor <.002 <.002 Terbufos <.013 <.013

2,4-DB <.24 <.24 Atrazine <.014 <.014 Thiobencarb <.002 <.002

Silvex (2,4.5-TP) <.021 <.21 Azinphos-methyl <.4 <.2 Triallate <.001 <.001

3-OH-carbofuran <.14 <.014 Benfluralin <.002 <.002 Trifluralin <.002 <.002

DNOC <.42 <.42 Butylate <.002 <.002 alpha-BHC <.002 <.002

Acifluorfen <.035 <.035 Carbaryl <.003 <.003 cis-Permethrin <.005 <.005

Aldicarb <.55 <.55 Carbofuran <.003 <.003 p,p'-DDE <.006 <.006

Aldicarb Sulfone <.1 <.1 Chlorpyrifos <.004 <.004

Aldicarb Sulfoxide <.021 <.021 Cyanazine <.15 <.015

Bentazon <.014 <.014 DCPA <.002 <.002

Bromacil <.035 <.035 2,6-Diethylanaline <.003 <.003 "The following are surrogate recoveries,

expressed as a percent."

Bromoxynil <.035 <.035 Deethyl atrazine <.0134 <.0127

Carbaryl <.008 <.008 Diazinon <.002 <.002

Carbofuran <.12 <.12 Dieldrin <.001 <.001 Diazinon Surrogate 100 82.2

Chloramben <.42 <.42 Disulfoton <.017 <.017 Terbuthylazine Surrogate122 113

Chlorothalonil <.48 <.48 EPTC <.002 <.002 alpha HCH Surrogate 109 101

Clopyralid <.23 <.23 Ethalfluralin <.004 <.004 BDMC, Surrogate 115 108

Dacthal <.017 <.017 Ethoprop <.003 <.003

Dicamba <.035 <.035 Fonofos <.003 <.003

Dichlobenil <1.2 <1.2 Lindane <.004 <.004

Dichlorprop <.032 <.032 Linuron <.002 <.002

Dinoseb <.035 <.035 Malathion <.005 <.005

Diuron <.02 <.02 Metolachlor <.008 <.007

Fenuron <.013 <.013 Metribuzin <.013 <.011

Fluorometuron <.035 <.035 Molinate <.004 <.004

Linuron <.018 <.018 Napropamide <.003 <.003

MCPA <.17 <.17 Parathion <.004 <.004

MCPB <.14 <.14 Methyl parathion <.006 <.006

Methiocarb <.026 <.026 Pebulate <.004 <.004

Methomyl <.017 <.017 Pendimethalin <.004 <.004

Neburon <.015 <.015 Phorate <.002 <.002

Norflurazon <.024 <.024 Prometon <.018 <.018

Oryzalin <.31 <.31 Pronamide <.003 <.003

Oxamyl <.018 <.018 Propachlor <.007 <.007

Picloram <.05 <.05 Propanil <.004 <.004

Propham <.035 <.035 Propargite <.013 <.013

Propoxur <.035 <.035 Simazine <.005 <.003

Triclopyr <.25 <.25 Terbuthiuron <.01 <.01
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 45

Table 13. Concentrations of pesticides in native water and percent recovery of spiked concentrations at Deer Creek and

South Plum Creek. Percent recovery is calculated as the spiked sample concentration divided by the spike concentration

expressed as a percent

[Concentrations are in micrograms per liter; E, estimated value; <less than; --no date available]

PESTICIDE

COMPOUNDS

ANALYZED BY

HPLC

DEER CREEK NEAR DORSEYVILLE, PA. SOUTH BRANCH PLUM CREEK AT FIVE POINTS, PA.

NATIVE

WATER

SPIKE

CONCENTRATION

SPIKED

SAMPLE

1

PERCENT

RECOVERY

SPIKED

SAMPLE

2

PERCENT

RECOVERY

NATIVE

WATER

SPIKE

CONCENTRATION

SPIKED

SAMPLE

1

PERCENT

RECOVERY

SPIKED

SAMPLE

2

PERCENT

RECOVERY

2,4,5-T <0.035 0.91 -- -- -- -- <0.035 0.91 0.82 90.2 0.9 99.0

2,4,5-D <.035 1.12 0.8 71.4 0.8 71.4 <.035 1.12 .87 77.7 .94 83.9

2,4-DB <.035 .92 .73 79.0 .72 77.9 <.035 .92 .7 75.8 .8 86.6

Silvex (2,4,5-

TP)

<.021 .95 .87 92.1 .89 94.2 <.021 .95 .89 94.2 .95 10.5

3-OH-carbofuran<.014 1.12 .92 82.1 .86 76.8 <.014 1.12 .84 75.0 .88 78.6

DNOC <.035 .99 E .87 87.7 E.85 85.7 <.035 .99 E.87 87.7 E.91 91.7

Acifluorfen <.035 1.10 .6 54.5 E.69 62.7 <.035 1.10 .98 89.1 1.04 94.5

Aldicarb <.016 1.12 .39 34.8 .56 5.0 <.016 1.12 -- -- -- --

Aldicarb Sulfone<.016 1.18 .3 25.4 .34 28.8 <.016 1.18 .22 18.6 .11 9.3

Aldicarb Sulfoxide<.021 1.17 .62 53.0 .87 74.4 <.021 1.17 1.1 94.0 .82 7.1

Bentazon <.014 .95 E .88 92.7 E.93 98.0 <.014 .95 E.87 91.7 .91 95.9

Bromacil <.035 1.09 .79 72.5 .8 73.4 <.035 1.09 .74 67.9 .79 72.5

Bromoxynil <.035 .95 .92 97.0 .92 97.0 <.035 .95 .87 91.8 .95 10.2

Carbaryl <.008 1.07 E 1.12 104.7 E.84 78.5 <.008 1.07 E1.07 10.0 E1.07 10.0

Carbofuran <.028 1.05 E 1.57 149.5 E1.61 153.3 <.028 1.05 1.04 99.0 .94 89.5

Chloramben <.011 .00 < .011 -- <.01 -- <.011 .00 <.011 -- E.011 --

Chlorothalonil <.035 1.10 E .78 7.9 .57 51.8 <.035 1.10 E.29 26.4 E.68 61.8

Clopyralid <.050 .90 <.05 5.6 <.05 5.6 <.050 .90 .16 17.8 .14 15.6

Dacthal <.017 .97 E.95 98.3 E.96 99.4 <.017 .97 E.91 94.2 .93 96.3

Dicamba <.035 .92 .24 26.1 .29 31.6 <.035 .92 .5 54.5 .71 77.3

Dichlobenil <.020 1.01 E.18 17.8 1.63 161.4 <.020 1.01 E.54 53.5 .58 57.4

Dichlorprop <.032 .95 .85 89.2 .82 86.0 <.032 .95 .81 85.0 .87 91.3

Dinoseb <.035 .94 .61 65.0 .69 73.6 <.035 .94 .87 92.8 .92 98.1

Diuron <.020 1.07 .9 84.1 .91 85.0 <.020 1.07 .88 82.2 .88 82.2

Fenuron <.013 1.18 .93 78.8 .92 78.0 <.013 1.18 .88 74.6 .94 79.7

Fluometuron <.035 1.05 1.16 11.5 1.22 116.2 <.035 1.05 .92 87.6 .91 86.7

Linuron <.018 1.08 .82 75.9 .82 75.9 <.018 1.08 .79 73.1 .78 72.2

MCPA <.050 .94 .72 77.0 E.86 92.0 <.050 .94 .83 88.8 .89 95.2

MCPB <.035 .94 .65 69.2 .63 67.1 <.035 .94 .7 74.5 .84 89.5

Methiocarb <.026 1.06 .89 84.0 .69 65.1 <.026 1.06 .79 74.5 .8 75.5

Methomyl <.017 1.04 1.16 111.5 .91 87.5 <.017 1.04 .9 86.5 .9 86.5

Neburon <.015 1.09 .9 82.6 .91 83.5 <.015 1.09 .78 71.6 .79 72.5

Norflurazon <.024 1.04 1.08 103.8 1.04 10.0 <.024 1.04 .94 9.4 .91 87.5

Oryzalin <.019 1.14 .8 7.2 .79 69.3 <.019 1.14 .73 64.0 .77 67.5

Oxamyl <.018 .99 .71 71.7 .56 56.6 <.018 .99 .71 71.7 .64 64.6

Picloram <.050 1.00 .59 59.0 .39 39.0 <.050 1.00 .72 72.0 .73 73.0

Propham <.035 1.08 .83 76.9 .8 74.1 <.035 1.08 E.76 7.4 .75 69.4

Propoxur <.035 1.07 .81 75.7 .81 75.7 <.035 1.07 .83 77.6 .85 79.4

Triclopyr <.050 .98 .92 94.3 .91 93.2 <.050 .98 .93 95.3 1.03 105.5
46 NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

Table 13. Concentrations of pesticides in native water and percent recovery of spiked concentrations at Deer Creek and

South Plum Creek. Percent recovery is calculated as the spiked sample concentration divided by the spike concentration

expressed as a percent—Continued

[Concentrations are in micrograms per liter; E, estimated value; <less than; --no date available]

PESTICIDE

COMPOUNDS

ANALYZED BY GC/MS

DEER CREEK NEAR DORSEYVILLE, PA. SOUTH BRANCH PLUM CREEK AT FIVE POINTS, PA.

NATIVE

WATER

SPIKE

CONCENTRATION

SPIKED

SAMPLE

1

PERCENT

RECOVERY

SPIKED

SAMPLE

2

PERCENT

RECOVERY

NATIVE

WATER

SPIKE

CONCENTRATION

SPIKED

SAMPLE

1

PERCENT

RECOVERY

SPIKED

SAMPLE

2

PERCENT

RECOVERY

2,6-Diethylanaline <0.003 0.1 0.09 90.0 0.09 86.0 <0.003 0.1 0.09 92.5 0.10 97.1

Acetochlor <.002 .1 .11 106.0 .09 91.0 <.002 .1 .12 119.0 .11 114.0

Alachlor <.002 .1 .11 108.0 .10 10.0 <.002 .1 .12 116.0 .11 114.0

Atrazine <.001 .1 .11 108.0 .10 10.0 .112 .1 .13 129.0 .13 127.0

Azinphos-methyl <.001 .1 .11 11.0 E.11 106.0 <.001 .1 E.34 34.0 E.40 399.0

Benfluralin <.002 .1 .11 109.0 .10 98.0 <.002 .1 .10 103.0 .10 103.0

Butylate <.002 .09 .11 119.0 .10 106.7 <.002 .09 .11 117.8 .11 118.9

Carbaryl <.003 .1 E.17 166.0 E.20 199.0 <.003 .1 E.21 211.0 E.21 207.0

Carbofuran <.003 .1 E.13 132.0 E.14 142.0 <.003 .1 .21 21.0 E.19 191.0

Chlorpyrifos <.004 .1 .10 104.0 .10 97.0 <.004 .1 .10 102.0 .10 97.4

Cyanazine <.004 .1 .09 88.0 .08 84.0 .016 .1 .14 135.0 .12 121.0

DCPA <.002 .09 .11 118.0 .10 107.8 <.002 .09 .09 104.9 .09 104.9

Deethyl Atrazine <.002 .1 E.03 25.0 E.02 24.0 E.008 .1 E.05 47.4 E.04 35.6

Diazinon <.002 .1 .10 99.0 .09 94.0 <.002 .1 .11 111.0 .11 106.0

Dieldrin <.001 .09 .08 86.0 .08 87.8 <.001 .09 .09 96.7 .09 95.6

Disulfoton <.017 .09 .05 57.7 .06 67.8 <.017 .09 .09 95.6 .08 89.0

EPTC <.002 .09 .11 117.8 .10 107.8 <.002 .09 .11 123.3 .11 125.6

Ethalfluralin <.004 .09 .11 118.9 .10 107.8 <.004 .09 .11 124.4 .11 123.3

Ethoprop <.003 .09 .10 114.4 .09 104.4 <.003 .09 .11 116.7 .10 114.4

Fonofos <.003 .1 .10 97.0 .09 92.0 <.003 .1 .11 106.0 .11 105.0

Lindane <.004 .09 .08 92.2 .09 95.6 <.004 .09 .12 137.8 .11 122.2

Linuron <.002 .09 .09 95.6 .09 94.4 <.002 .09 .13 146.7 .13 147.7

Malathion <.005 .1 .10 101.0 .10 95.0 <.005 .1 .12 115.0 .12 115.0

Metolachlor <.002 .09 .12 127.8 .11 12.0 .011 .09 .13 146.7 .13 143.3

Metribuzin <.004 .1 .10 104.0 .10 96.0 <.020 .1 .10 96.0 .09 91.0

Molinate <.004 .1 .10 104.0 .10 10.0 <.004 .1 .10 101.0 .10 104.0

Napropamide <.003 .1 .09 87.0 .10 95.0 <.003 .1 .11 108.0 .10 98.6

Parathion <.004 .1 .10 103.0 .11 112.0 <.004 .1 .12 117.0 .12 12.0

Methyl parathion <.006 .1 .11 108.0 .10 102.0 <.006 .1 .12 123.0 .13 126.0

Pebulate <.004 .09 .10 113.3 .10 11.0 <.004 .09 .10 115.6 .11 117.8

Pendimethalin <.004 .1 .09 93.0 .07 74.0 <.004 .1 .11 111.0 .11 112.0

Phorate <.002 .1 .07 7.0 .07 65.0 <.002 .1 .10 96.0 .09 93.4

Prometon <.018 .1 .11 106.0 .10 98.0 <.018 .1 .12 122.0 .11 11.0

Propachlor <.007 .1 .12 116.0 .11 113.0 <.007 .1 .12 119.0 .12 123.0

Propanil <.004 .1 .11 105.0 .10 98.0 <.004 .1 .11 11.0 .11 11.0

Propargite <.013 .09 .09 101.1 .09 96.7 <.013 .09 .10 111.1 .09 103.8

Pronamide <.003 .1 .10 101.0 .10 95.0 <.003 .1 .10 10.0 .10 103.0

Simazine <.005 .1 .10 97.0 .09 93.0 .008 .1 .11 111.0 .11 106.0

Terbuthiuron <.010 .1 .11 112.0 .11 11.0 <.010 .1 .10 102.0 .11 106.0

Terbacil <.007 .1 E.07 66.0 E.06 64.0 <.007 .1 E.10 95.7 E.07 67.4

Terbufos <.013 .1 .09 87.0 .08 82.0 <.013 .1 .11 108.0 .10 101.0

Thiobencarb <.002 .1 .10 103.0 .10 96.0 <.002 .1 .11 107.0 .11 106.0

Triallate <.001 .1 .10 95.0 .09 86.0 <.001 .1 .10 97.7 .10 96.6

Trifluralin <.002 .1 .11 109.0 .10 99.0 <.002 .1 .11 109.0 .11 107.0

alpha-BHC <.002 .1 .09 94.0 .09 9.0 <.002 .1 .10 10.0 .10 103.0

cis-Permethrin <.005 .03 .02 5.0 .01 2.0 <.005 .03 .02 53.3 .02 5.0

p,p'- DDE -- .1 .06 62.0 .03 34.0 <.006 .1 .07 7.8 .07 68.9
ALLEGHENY & MONONGAHELA RIVER BASINS STUDY UNIT 47

Table 14. Concentrations of volatile organic compounds in blank samples collected at Deer Creek, February 2, April 10,

and June 5, 1997, and April 16, 1998

[Concentrations are in micrograms per liter; E, estimated value; <, less than; --, no data available]

VOC 02-07-

1997

04-10-

1997

06-05-

1997

04-16-

1998 VOC 02-07-

1997

04-10-

1997

06-05-

1997

04-16-

1998

Acetone E1.4 5 4.9 4.9 Freon 113 <0.05 - <0.032 <0.032

Acrolein <2 <2 <1.43 -- Tetrahydrofuran <5 <5 <1.15 <1.15

Acrylonitrile <2 <2 <1.23 <1.23 Hexachlorobutadiene <.2 <.2 <.142 <.142

Benzene <.05 E.005 <.032 <.032 2-Hexanone <5 <5 <.746 <.746

Bromobenzene <.05 <.05 <.036 <.036 Isodurene <.05 -- <.24 <.24

Chlorobenzene <.05 <.05 <.028 <.028 Methymethacrylate <1 <1 <.35 <.35

o-Dichlorobenzene <.05 <.05 <.048 <.048 Ethylmethacrylate <1 <1 <.278 <.278

1,3-Dichlorobenzene <.05 <.05 <.054 <.054 Methyl bromide <.1 -- <.148 <.148

1,4-Dichlorobenzene E.04 E.007 <.05 <.05 Methyl chloride <.2 -- <.254 <.254

1,2,3 -Trichlorobenzene <.2 <.2 <.266 <.266 Bromochloromethane <.1 <.1 <.044 <.044

1,2,4-Trichlorobenzene <.2 <.2 <.188 <.188 Dibromochloromethane <.1 <.1 <.182 <.182

1,2,3-Trimethylbenzene <.05 <.05 <.124 <.124 Dibromomethane <.1 <.1 <.05 <.05

1,2,4-Trimethylbenzene E.02 <.05 E.009 <.056 Bromodichloromethane <.1 <.1 <.048 <.048

1,3,5-Trimethylbenzene <.05 <.05 <.044 <.044 Dichlorodifluoromethane <.2 <.2 E.08 <.096

Ethylbenzene E.009 <.05 <.03 <.03 Methyl iodide <.05 -- <.076 <.076

n-Propylbenzene <.05 <.05 <.042 <.042 Carbon tetrachloride <.05 -- <.088 <.088

Isopropyl-Benzene <.05 <.05 <.032 <.032 Bromoform <.2 <.2 <.104 <.104

n-Butylbenzene <.05 <.05 <.186 <.186 Chloroform <.1 <.05 <.052 <.052

sec-Butylbenzene <.05 <.05 <.043 <.048 Trichlorofluoromethane <.1 -- <.092 <.092

tert-Butylbenzene <.05 <.05 <.096 <.096 Methyl acrylate <2 <2 <.612 <.612

2-Butene T-1, 4-D 5 -- <.692 <.692 Meth acrylonitrile <2 <2 <.57 <.57

Carbon disulfide <.05 <.05 <.08 <.08 Methyl ethyl ketone 1.6 -- 1.65 1.65

1,2-Dibromoethane <.1 -- <.036 <.036 Methyl isobutyl ketone 5 -- <.374 <.374

Chloroethane <.1 <.1 <.12 <.12 Prehnitene <.05 -- <.23 <.23

1,1-Dichloroethane <.05 <.05 <.066 <.066 Dichloropropane <.05 -- <.068 <.068

1,2-Dichloroethane <.05 <.05 <.134 <.134 2,2-Dichloropropane <.05 <.05 <.078 <.078

1,1,1-Trichloroethane <.05 <.005 <.032 <.032 1,3-Dichloropropane <.05 <.05 <.116 <.116

1,1,2-Trichloroethane <.1 <.1 <.064 <.064 1,2,3 Trichloropropane <.2 <.2 <.07 <.07

1,1,1,2-Tetrachloroethane <.05 <.05 <.044 <.044 Dibromochloropropane <.5 <.5 <.214 <.214

1,1,2,2-Tetrachloroethane <.1 <.1 <.132 <.132 3-Chloropropene <.1 <.1 <.196 <.196

Hexachloroethane <.05 <.05 <.362 <.362 1,1-Dichloropropene <.05 <.05 <.026 <.026

Bromoethene <.1 <.1 <.1 <.1 cis-1, 3-Dichloropropene <.1 <.1 <.092 <.092

Methylene chloride <.1 E.01 <.382 <.382 trans-1,3-Dichloropropene<.1 <.1 <.134 <.134

1,1-Dichloroethylene <.05 -- <.44 <.44 Styrene <.05 <.05 <.042 <.042

cis-1, 2-Dichloroethylene <.05 <.05 <.038 <.038 Toluene .11 <.05 <.038 <.038

Transdichloroethene <.05 <.05 <.032 <.032 o-Chlorotoluene <.05 <.05 <.042 <.042

Trichloroethylene <.05 -- <.038 <.038 p-Chlorotoluene <.05 <.05 <.056 <.056

Tetrachloroethylene <.05 -- <.038 <.038 o-Ethyltoluene <.05 <.05 <.1 <.1

Diisopropyl ether <.01 <.01 <.098 <.098 P-Isopropyl toluene <.05 <.05 <.11 <.11

Ethyl ether <.01 -- <.17 <.17 Vinyl Acetate <5 <5 -- --

MTBE <.1 <.1 <.112 <.112 Vinyl Chloride <.1 <.1 <.112 <.112

Ethyl tert-butyl ether <.1 <.1 <.054 <.054 o-Xylene E.02 <.05 <.064 <.064

tert-Pentyl methyl ether <.1 -- <.112 <.112 m-and p-Xylene E.04 <.05 <.064 <.064