WATER-QUALITY CHARACTERISTICS OF URBAN 

STORM RUNOFF AT SELECTED SITES IN 

EAST BATON ROUGE PARISH, LOUISIANA, 

FEBRUARY 1998 THROUGH APRIL 2002

By C. Paul Frederick

_____________________________________________________________________________________

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 03-4212

Prepared in cooperation with the

CITY OF BATON ROUGE and

EAST BATON ROUGE PARISH

Baton Rouge, Louisiana

2003
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of trade, product, industry, or firm names in this report is for descriptive or location purposes only and does 

not constitute endorsement of products by the U.S. Government nor impute responsibility for any present or potential 

effects on the natural resources.

_____________________________________________________________________________________

For additional information contact: Copies of this report can be purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

3535 S. Sherwood Forest Blvd., Suite 120 Box 25286

Baton Rouge, LA 70816 Denver, CO 80225

E-mail: dc_la@usgs.gov E-mail: infoservices@usgs.gov

Fax: (225) 298-5490 Fax: (303) 202-4693

Telephone: (225) 298-5481 Telephone (toll free): 1-888-ASK-USGS

Home page: www.la.water.usgs.gov
iii

CONTENTS

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

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

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

General Description of Study Area .................................................................................................3

Acknowledgments ...........................................................................................................................3

Methods of Study ..........................................................................................................................................3

Definitions........................................................................................................................................3

Site Selection .................................................................................................................................. 5

Data Collection and Analysis ..........................................................................................................5

Precipitation ...........................................................................................................................5

Streamflow .............................................................................................................................5

Water Quality .........................................................................................................................6

Quality Assurance and Quality Control ..........................................................................................6

Calculation of Estimated Annual Contaminant Load .....................................................................7

Watershed Characteristics and Site Description ...........................................................................................7

Water-Quality Characteristics of Urban Storm Runoff ..............................................................................13

Average Event Mean Concentrations for Selected Properties and Constituents ...........................14

Estimated Annual Contaminant Load for Selected Properties and Constituents...........................15

Analysis of Quality-Control Data ...............................................................................................................16

Summary .....................................................................................................................................................16

Selected References ....................................................................................................................................17

Appendixes: ................................................................................................................................................19

1. Runoff and Water-Quality Data

1A-1D. Summary of runoff and water-quality data from a drainage canal at:

1A. Lobdell Boulevard in an established commercial land-use area, 

Baton Rouge, Louisiana during selected storms, 

February 15, 1998-May 10, 1999 .............................................................. 20

1B. Tom Drive in an industrial land-use area, Baton Rouge,

Louisiana, during selected storms, February 15, 1998-May 10, 1999....... 21

1C. Sunbelt Court in a new commercial land-use area, 

Baton Rouge metropolitan area, Louisiana, during selected

storms, July 24, 1998-April 8, 2002 ......................................................... 22

1D. Goodwood Boulevard in a residential land-use area, 

Baton Rouge, Louisiana, during selected storms,

July 22, 1998-April 8, 2002....................................................................... 23

2. Minimum detection levels of water-quality properties and constituents..................................24
iv

FIGURES

1-5. Maps showing location of the:

1. Sites in the storm-runoff monitoring network for East Baton Rouge Parish, 

Louisiana, 1998-2002.................................................................................................................... 4

2. Established commercial land-use area, Lobdell Boulevard, Baton Rouge, 

Louisiana, 1998 ............................................................................................................................ 9

3. Industrial land-use area, Tom Drive, Baton Rouge, Louisiana, 1998.......................................... 10

4. New commercial land-use area, Sunbelt Court, Baton Rouge metropolitan area, 

Louisiana, 1998........................................................................................................................... 11

5. Residential land-use area, Goodwood Boulevard, Baton Rouge, Louisiana, 1998 ..................... 12

TABLES

1. Coefficient used in the computation of annual contaminant load and summary of 

land use in East Baton Rouge Parish, Louisiana........................................................................... 8

2. Average event-mean concentration for selected water-quality properties and 

constituents for four land-use areas within a storm-runoff monitoring network 

in East Baton Rouge Parish, Louisiana, 1998-2002.................................................................... 14

3. Estimated annual contaminant loads and yields for selected water-quality properties

and constituents for four land-use areas within a storm-runoff monitoring network 

in East Baton Rouge Parish, Louisiana, 1998-2002.................................................................... 15

4. Analysis of quality-control data for two land-use areas in East Baton Rouge Parish, 

Louisiana, July 28, 2001 ............................................................................................................. 16

CONVERSION FACTORS AND ABBREVIATED WATER-QUALITY UNITS

Multiply By To obtain

inch (in.) 25.4 millimeter (mm)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

foot (ft) 0.3048 meter (m)

cubic foot (ft3) 0.02832 cubic meter (m3)

acre 4,047 square meter (m2)

mile (mi) 1.609 kilometer (km)

gallon (gal) 0.003785 cubic meter (m3

)

pound per year (lb/yr) 0.4536 kilogram per year (kg/yr)

pounds per acre per year [(lb/acre)/yr] 1.121 kilograms per hectare per year [(kg/ha)/yr]

Temperature in degrees Celsius (°C) can be converted to degrees Fahrenheit (°F) as follows: °F = 1.8 (°C) + 32.

Abbreviated water-quality units:

colonies per 100 milliliters (cols/100 mL)

microsiemens per centimeter at 25 degrees Celsius (μS/cm)

milligrams per liter (mg/L)

micrograms per liter (μg/L)
1

WATER-QUALITY CHARACTERISTICS OF URBAN 

STORM RUNOFF AT SELECTED SITES IN 

EAST BATON ROUGE PARISH, LOUISIANA, 

FEBRUARY 1998 THROUGH APRIL 2002

By C. Paul Frederick

ABSTRACT

Water was sampled at four watersheds for continued evaluation of urban storm runoff in East Baton 

Rouge Parish, Louisiana, during February 1998 through April 2002. Eighteen samples were collected 

from four watersheds representing land uses characterized predominantly as established commercial, 

industrial, new commercial, and residential. Results of water-quality analyses enabled calculation of 

event-mean concentrations and estimated annual contaminant loads and yields of storm runoff from 

nonpoint sources for 12 water-quality properties and constituents. The following water-quality data are 

reported: physical and chemical-related properties, fecal coliform and enterococci bacteria, major 

inorganic ions, nutrients, trace elements, and organic compounds. 

The residential land-use is the largest of the watersheds (550 acres), which resulted in high 

estimated annual contaminant loads compared to other watersheds for 8 of the 12 water-quality properties 

and constituents. This may indicate that the size of the watershed and runoff from residences with their 

associated contaminants had substantial effects on annual loads within this land use. The industrial landuse area had the highest estimated annual contaminant loads for metals, followed by the residential landuse area. However, when comparing yields among the watersheds, the industrial watershed had the 

highest yield for 9 of the 12 water-quality properties and constituents, whereas the residential watershed 

had the lowest yield for 7 of the 12. The industrial watershed yielded more metals per acre per year than 

any other watershed. Zinc yields were 2.71 pounds per acre per year from the industrial watershed, 

compared to 0.35 pounds per acre per year from the residential watershed, which was the lowest of all 

the watersheds. Lead concentrations exceeded the U.S. Environmental Protection Agency Maximum 

Contaminant Level of 15 μg/L (micrograms per liter) for drinking water standards in 10 of 18 samples. 

Low-level concentrations of mercury were detected twice at both the new commercial and residential 

sites, with all concentrations at or just above reporting limits. The average dissolved phosphorus 

concentrations from each land use were two to four times higher than the U.S. Environmental Protection 

Agency criterion of 0.05 milligrams per liter. Diazinon, which is widely used as a general-purpose 

insecticide for lawns and gardens, was detected in all 18 samples. The maximum diazinon concentration 

detected, 2.7 μg/L, was from the residential site. Malathion, another insecticide used on lawns, gardens, 

and plants, also was detected at least once from each site, but all concentrations were below the minimum 

detection limit of 0.1 μg/L. 
2

INTRODUCTION

Since the 1960’s, urban storm runoff has been known to have potentially adverse effects on the 

water quality of receiving waters. The work of Weibel and others (1964) and Makepeace and others 

(1995) indicated that elevated concentrations of various chemical constituents were present in urban 

storm runoff. During dry periods, contaminants accumulate on land surfaces until they are mobilized by 

precipitation, washed into the urban drainage system, and eventually discharged into receiving waters as 

storm runoff. Generally, the contaminants carried by storm runoff do not come from a single identifiable 

source. This contamination comes from multiple or diffuse sources and is referred to as nonpoint-source 

contamination. The volume of urban storm runoff increases as metropolitan areas expand and as rural 

land is developed for residences, commercial businesses, industrial facilities, shopping centers, and 

recreational areas. 

The Federal Clean Water Act, which was amended in 1987, mandated that the U.S. Environmental 

Protection Agency (USEPA) develop a permitting program to mitigate nonpoint-source contamination in 

urban storm runoff. Consequently, Federal stormwater regulations (U.S. Environmental Protection 

Agency, 1991), in accordance with the permit application process of the National Pollutant Discharge 

Elimination System (NPDES), require cities that have a population of 100,000 or more to characterize 

the quantity and quality of their storm runoff. In 2002, the estimated population of the City of Baton 

Rouge was 228,000. The estimated population of the Baton Rouge metropolitan area was 413,000 (U.S. 

Bureau of the Census, 2002).

The urban storm-runoff regulations mandated by the USEPA require continued monitoring of data 

collection sites following their initial characterization for quantity and quality of storm runoff by the City 

of Baton Rouge, East Baton Rouge Parish. As in any metropolitan area, municipal storm-sewer systems 

(MS4) have been installed to provide drainage for developed areas. Although discharge from the MS4 

often has lower concentrations of many pollutants than discharge from industrial and municipal waste 

water, the pollutant concentrations associated with discharge from the MS4 can have significant effects 

on water quality. To meet technical data requirements of the USEPA stormwater permit application for 

the Baton Rouge metropolitan area, the U.S. Geological Survey (USGS) entered into a cooperative 

agreement with the City of Baton Rouge and East Baton Rouge Parish government in 1992. The City of 

Baton Rouge and East Baton Rouge Parish have a combined governmental system. Through the 1992 

agreement, a data-collection network was established to characterize the quantity and quality of urban 

storm runoff from watersheds in different land-use areas within East Baton Rouge Parish. From April 

1993 to June 1995, the USGS collected data used for the initial characterization of storm-runoff quantity 

and quality for the City/Parish of East Baton Rouge (Demcheck and others, 1998). In 1997, this 

information was used for the design of representative sampling for continued monitoring of datacollection sites, as required by USEPA (U.S. Environmental Protection Agency, 1997). Within this 

design, the undeveloped land-use site was discontinued, and the fifth site was relocated to represent 

highway land use.

Purpose and Scope

This report describes continued evaluation of water-quality characteristics of urban storm runoff 

from watersheds that represent different types of land use in East Baton Rouge Parish. Sites were 

selected in established commercial, industrial, new commercial, and residential land uses. Rainfall, 

streamflow, and water-quality data collected at four of the five sites during storms are presented. 

Eighteen samples were collected during February 1998 through April 2002. The reported water-quality 

properties and constituents include physical and chemical-related properties, fecal coliform and 

enterococci bacteria, major inorganic ions, nutrients, trace metals, and organic compounds. Average 
3

event-mean concentrations (EMC’s) of 12 selected water-quality properties and constituents were used 

to estimate both individual storm and annual storm-runoff loads and yields. Average EMC’s were 

calculated by using the EMC’s for storms collected from each watershed representing a particular land 

use. Urbanization can change the natural flow of surface water and intrude more sediment, nutrients, and 

contaminants to the environment. The USGS will continue monitoring selected land uses to gather 

information on water-quality conditions in urban watersheds, which could aid other communities in 

similar environmental settings.

General Description of Study Area

East Baton Rouge Parish (fig. 1) covers an area of approximately 293,000 acres between the 

Mississippi River and the Amite River. The parish has an extensive levee system along the Mississippi 

River; therefore, no substantial drainage occurs from East Baton Rouge Parish into the Mississippi River. 

Most of the parish is within the watershed of the Amite River. The Amite River flows generally 

southeastward to Lake Maurepas, Lake Pontchartrain, and the Gulf of Mexico. 

The climate of East Baton Rouge Parish is humid-subtropical, but subject to continental polar 

fronts during the winter. Warm, moist air from the Gulf of Mexico provides abundant moisture during 

late spring and summer. The summer is characterized by hot temperatures and intense but brief 

thunderstorms generating greater amounts of runoff than in winter. The fall, late September through 

November, is usually warm and relatively dry. The winter is generally cool and mild. Winter rainfall 

associated with passing cold fronts can last hours or days, but is less intense than in summer, and the 

ground may remain saturated for days. (J.M. Grymes III, Louisiana Office of State Climatology, written 

commun., 1993; Elizabeth Mons, Louisiana Office of State Climatology, written commun., 2002).

Acknowledgments

The author thanks Jorge M. Ferrer and Tran Nguyen of the Department of Public Works, City of 

Baton Rouge, for their advice and support throughout this project. Appreciation also is extended to 

Elizabeth Mons of the Louisiana Office of State Climatology for providing updated rainfall records for 

East Baton Rouge Parish.

METHODS OF STUDY

Representative sampling consisted of a smaller subset of properties and constituents than needed 

for the initial characterization. The smaller subset provided data useful in generating long-term averages 

and trends in the constituents collected, along with the amount of storm runoff from each site. Results 

of the representative sampling and water-quality analyses were used to determine EMC’s and estimated 

annual contaminant loads of 12 selected water-quality properties and constituents in storm runoff. The 

EMC is determined from the analysis of flow-weighted composite samples. 

Definitions

For the purposes of this report, permit regulations stipulate that runoff must be sampled from a 

storm greater than 0.1 in. in magnitude that occurs at least 72 hours from the previously measurable storm 

(U.S. Environmental Protection Agency, 1997, pt. V. A. 4. c). The 72-hour storm interval is waived where 

discharge is not measurable and rainfall is less than 0.1 in. during the season when sampling is being 

done. Also, for this permit, three seasons were defined for this geographic region: December to April, 

May to August, and September to November. 

5

Site Selection

Initially (1997), five sampling sites were selected to represent the different types of land use in East 

Baton Rouge Parish. The land uses represented were established commercial, industrial, new 

commercial, residential, and highway. However, in December 1997, a truck overturned and spilled 

ethylene dichloride (EDC) upstream from the highway gaging station; therefore, no discharge rating was 

developed to begin initial characteristic sampling of this site.

Watershed size was an important factor in site selection. The watershed had to be large enough to 

provide a minimum 3-hour discharge period for storm runoff, but small enough to represent a single 

dominant land use. If the discharge was less than 3 hours, subsamples of the discharge were collected 

until the volume of runoff diminished, or the level of the stream declined below the sample intake line. 

To meet these requirements, the selected watersheds were at least 60 acres but no more than 600 acres.

Data Collection and Analysis

The water-quality-data-collection network consisted of four monitoring sites that received storm 

runoff from four watersheds (fig. 1). A monitoring station was constructed at each of the four sites and 

equipped with a rain gage, datalogger, and sampler. During the initial characterization phase of storm 

runoff, a relation between the amount of precipitation that fell on a watershed and the volume of runoff 

discharged from that watershed was determined. This same relation was used during the representative 

sampling, which enabled the automatic sampler to be programmed so that subsamples could be collected 

and composited to be representative of flow, while ensuring that the capacity of the sampler would not 

be exceeded during the initial 3 hours of sustained discharge.

The subsamples were stored on-site in as many as four 1-gal containers during the collection 

process. Once sampling was completed, the four 1-gal containers were removed, chilled, and transported 

to the USGS laboratory in Baton Rouge for processing and preservation.

 No data are presented for the highway land-use site due to the EDC spill in 1997. In 1999, samples 

for analysis of volatile organic compounds were collected to ensure a safe working level of EDC had been 

reached.

 Precipitation

The intensity and duration of precipitation were measured for each site by a tipping-bucket rain 

gage at the monitoring station. The rain gage was installed at a site which was unobstructed by overhead 

objects within 45 degrees of the collection funnel. Precipitation amounts were recorded at 15-minute 

intervals and summed to obtain the cumulative precipitation measurement. Precipitation data were 

assumed to represent the entire watershed.

Streamflow

Gage height was measured and recorded at each monitoring station using a pressure-sensitive, 

bubbler-regulated stage gage. The bubbler regulator maintained a constant rate of air flowing through a 

tube that extended from the monitoring station to an orifice at the bottom of the channel. As stage rose, 

greater pressure was required to maintain a constant flow rate through the tube. Pressure changes were 

measured, converted to gage height, and recorded by the datalogger. Gage-height measurements with 

this system were affected minimally by rapid changes in temperature.
6

Streamflow and storm-runoff volumes were quantified at each monitoring station using a stagedischarge rating. Manual discharge measurements were made at various gage heights using either a 

Price AA or pygmy meter and the 0.6-depth or 0.2- and 0.8-depth method (Buchanan and Somers, 1969; 

Rantz and others, 1982). The various gage heights and their respective discharge volumes were entered into 

the datalogger, and a three-point interpolation method was used to create the stage-discharge rating. Using 

this stage-discharge rating, the datalogger then computed both instantaneous discharge and total discharge 

volume during an entire storm.

Water Quality

Samples of storm runoff were collected for each watershed by automated samplers, which collected 

flow-weighted or proportional composite samples for at least the initial 3 hours of each storm. If the 

discharge was less than 3 hours, subsamples of the discharge were collected until the volume of runoff 

diminished, or the level of the stream declined below the sample intake line. Each sampler was programmed 

according to individual land-use characteristics. The rain gage, datalogger, and sampler were integrated to 

compose a reliable, automatic data-collection system that was programmed according to the watershed’s 

characteristics, such as size, amount of impervious area, and land use. The rain gage transmitted a pulse to 

the datalogger each time 0.01 in. of rainfall was collected. When 0.1 in. of rainfall fell in 0.5 hours, or a 

predetermined stage was reached, the datalogger activated the sampler to collect a 0.2-gal subsample. This 

process continued until the capacity of the sampler was met or the volume of runoff diminished. Aeration 

and exposure of samples to contamination during sample collection were minimized by use of a peristaltic 

pump. The result was a representative sample proportionally equivalent to the volume of storm runoff from 

that watershed. To be considered a representative composite sample, at least a 2-gal sample was collected.

Project personnel measured selected properties and manually collected water samples for analysis of 

selected constituents. The measurements and depth-integrated samples were collected in the appropriate 

containers by wading the stream during the first hour of runoff from the watershed. Specific conductance, 

pH, water temperature, and dissolved oxygen were measured. Samples collected manually were analyzed 

for biochemical oxygen demand, concentrations of fecal coliform and enterococci bacteria, and oil and 

grease. After collection, the samples were transported to the USGS laboratory in Baton Rouge for further 

preparation and processing or analysis.

Water samples were composited with a fluoropolymer splitter. The cone splitter was used to prepare 

representative subsamples for the appropriate chemical analyses. Samples for dissolved inorganic, nutrient, 

and trace-element analyses were passed through 0.45-micrometer nitrocellulose filters and treated with the 

appropriate preservative(s) for later analysis at the USGS National Water-Quality Laboratory in Denver, 

Colorado, using methods described by Fishman and Friedman (1989). All water samples for analysis were 

stored at 4o

C until shipped. Samples collected for analysis of fecal coliform and enterococci bacteria were 

collected in a sterilized glass bottle and processed within 4 hours of collection. Bacteria samples were 

analyzed at the USGS laboratory in Baton Rouge using the membrane-filter method described by Britton and 

Greeson (1988).

Quality Assurance and Quality Control

The purpose of the quality assurance and control procedures was to ensure the accuracy of the data. 

These procedures included the collection of replicate samples, equipment-blank samples, and the 

compilation of percent-recovery data. During the sample-splitting process, replicate storm-runoff samples 

were collected simultaneously to check the precision of laboratory techniques and sample-splitting. Two 

replicate samples were processed on July 28, 2001, one from the new commercial site and the other from the 
7

residential site. Equipment blanks of inorganic-free and organic-free water were passed through samplecollection equipment from each site to ensure proper cleaning of all equipment in contact with previous 

storm-runoff samples. Replicate and equipment-blank samples were preserved and processed in the 

same manner as storm-runoff samples. Standard forms were developed and used to document field data 

collection, to request analytical services, and to provide a chain of custody when shipping water samples.

Calculation of Estimated Annual Contaminant Load

An equation referred to as the "simple method" (U.S. Environmental Protection Agency, 1992), 

adapted from Schueler (1987), was used to estimate annual contaminant loads for urban watersheds in 

East Baton Rouge Parish. The "simple method" is described in detail and provides a quick and reasonable 

estimate of loads for the NPDES Permit (U.S. Environmental Protection Agency, 1992, sect. 5.4.3, 

p. 5-14). Values of annual rainfall, watershed characteristics, and a selected water-quality concentration 

are used in the equation to estimate annual contaminant loads. The "simple method" equation for 

estimation of annual contaminant loads in storm runoff is:

(1)

where:

Li is annual contaminant load for site i, in lb/yr;

P is average annual precipitation, in in/yr;

CF is a correction factor that adjusts for storms where no runoff occurs (a value of 0.9 was used);

Rvi is runoff coefficient for the watershed of site i;

Ci is average event-mean concentration (EMC) of contaminant at site i, in mg/L; and

Ai is watershed area for site i, in acres.

WATERSHED CHARACTERISTICS AND SITE DESCRIPTION

The frequency of sampling for the selected watersheds was determined by the occurrence of 

storms. Rainfall data obtained for the period 1997-2001, showed that East Baton Rouge Parish had an 

average annual rainfall of 54.9 in., 8.2 in. below the 30-year normal average of 63.1 in., (Elizabeth Mons, 

Louisiana Office of State Climatology, written commun., 2002). Based on monthly Palmer Drought 

Severity Indices, 1998-2001, much of East Baton Rouge Parish was in moderate to severe drought 

conditions. For 1997-2001, 9 of the 12 monthly averages were below 30-year normal averages for East 

Baton Rouge Parish. Due to drought conditions, fewer storms occurred within each watershed, causing 

an unequal distribution of samples collected from each site. 

East Baton Rouge Parish consists of about 22.5 percent developed land (table 1). About 

3.5 percent of the developed land is established and new commercial; 2.3 percent is industrial; and 

16.7 percent is residential (Wilbur Smith Associates, 1992). Runoff coefficients also were calculated for 

the four watersheds and are presented in table 1.

Li

( ) P ( ) CF Rvi ( )

12 ---------------------------------- Ci ( ) Ai = ( )( ) 2.72
8

Table 1. Coefficient used in the computation of annual contaminant load and summary of land use in 

East Baton Rouge Parish, Louisiana

1

Land used for agriculture is not included in this summary.

2

Land-use summary from Wilbur Smith Associates (1992).

3

Rounded number.

4

N/A, not applicable.

The four sites selected to represent the watersheds were located in areas that were safely accessible 

during storms and darkness. The channel type was documented, as well as any culverts, ditches, and drains 

that control flow. Project personnel extensively surveyed the watersheds using city and parish maps and 

on-site observations to determine acreage, land use, and directions of drainage.

Site 1, located in the established commercial land-use area, was at an open-channel, unlined 

drainage canal at Lobdell Boulevard (fig. 2). The sampling site was approximately 400 ft downstream 

from a double 5-ft by 4-ft box culvert under Lobdell Boulevard. The drainage canal received storm runoff 

from this 63-acre watershed through storm drains located along Harry Drive, Lobdell Boulevard, and 

within a shopping center parking lot. Runoff from four storms was collected for this land use.

Site 2, located in the industrial land-use area, was at an open-channel, unlined drainage canal at Tom 

Drive, 0.1 mi east of Wooddale Boulevard (fig. 3). The sampling site was downstream from a double 7-ft 

by 5-ft box culvert at Tom Drive. The drainage canal received storm runoff from this 109-acre watershed 

through storm drains located along Wooddale Boulevard, South Choctaw Drive, Tom Drive, and at various 

industrial businesses, warehouses, and distribution centers. Runoff from three storms was collected for 

this land use.

Site 3, located in a new and rapidly developing commercial area (new commercial) of East Baton 

Rouge Parish, was at an open-channel, concrete-lined drainage canal (fig. 4). The site received storm 

runoff from this 157-acre watershed through drains located along Industriplex Boulevard, Sunbelt Court, 

and Exchequer Street, as well as small ditches. Runoff from six storms was collected for this land use.

Site 4, located in the residential land-use area, was at an open-channel, concrete-lined drainage canal 

at Goodwood Boulevard, about 0.5 mi east of South Sherwood Forest Boulevard (fig. 5). The drainage 

canal received storm runoff from this 550-acre watershed through storm drains underlying streets. The 

sampling site was just upstream from a double 9-ft by 7-ft box culvert under Goodwood Boulevard. Most 

of the storm drains in this watershed were built from the late 1960’s to early 1970’s. This area included 

mostly single-family residences. Runoff from five storms was collected for this land use.

Primary land use1

Land use for East Baton Rouge Parish (1988)2 Runoff coefficient 

(Rvi) for network 

Acres Percent of total watershed

Established commercial 4,909 1.75 0.99 (site 1)

Industrial 6,488 2.30 .81 (site 2)

New commercial 4,909 1.75 .51 (site 3)

Residential 47,430 16.7 .39 (site 4)

TOTAL3 63,700 22.5 N/A4




13

WATER-QUALITY CHARACTERISTICS OF URBAN STORM RUNOFF

A total of 18 water-quality samples were collected from the four watersheds in East Baton Rouge 

Parish during February 1998 through April 2002. At the established commercial site, four stormwater 

samples were collected (appendix 1A). Nutrient concentrations for total nitrogen ranged from 0.73 to 

2.3 mg/L; ammonia plus organic (Kjeldahl) nitrogen, 0.43 to 1.7 mg/L; total phosphorus, 0.06 to 

0.31 mg/L; and dissolved phosphorus, 0.03 to 0.22 mg/L. Fecal coliform bacteria are used as indicators 

of the sanitary conditions of waters because they originate from the intestinal tracts of warmblooded 

animals. Fecal coliform concentrations ranged from 1,100 to 100,000 cols/100 mL. Enterococci 

bacteria are indicators for recreational waters. Enterococci concentrations ranged from 4,930 to 

5,000 cols/100 mL. Lead was detected in all four samples, with concentrations ranging from 5.7 to 

40 μg/L, with one sample exceeding than the USEPA Maximum Contaminant Level (MCL) of 15 μg/L 

for drinking water. No mercury was detected. Diazinon, which is widely used as a general-purpose 

insecticide for lawn and gardens, was detected in four samples, ranging in concentrations from 0.01 to 

0.79 μg/L. Malathion, an insecticide used on lawns, gardens, and plants, was detected at 0.01 μg/L in 

two samples at concentrations below the minimum detection limit of 0.1 μg/L. Total polychlorinated 

biphenyls (PCB’s) were detected in two of four samples at concentrations ranging from 0.12 to 0.2 μg/L, 

just above the reporting limit of 0.1 μg/L. No oil and grease was detected.

At the industrial site, three stormwater samples were collected (appendix 1B). Nutrient 

concentrations for total nitrogen ranged from 1.2 to 2.6 mg/L; ammonia plus organic (Kjeldahl) nitrogen, 

0.71 to 1.7 mg/L; total phosphorus, 0.15 to 0.47 mg/L; and dissolved phosphorus, 0.04 to 0.22 mg/L. 

All three lead concentrations were at least 5 times the MCL of 15 mg/L. Fecal coliform concentrations 

ranged from 520 to 80,000 cols/100 mL. Enterococci concentrations ranged from 630 to 

2,200 cols/100 mL. Analysis for bacteria from the May 10, 1999, storm was unsuccessful due to 

incubation problems. Cadmium was detected twice and was higher than the reporting limits of 1 μg/L. 

Copper was detected in three samples, with concentrations 2 to 3 times higher than the reporting limit of 

10 μg/L. No mercury was detected. Diazinon was detected in all three samples, with concentrations 

ranging from 0.05 to 0.17 μg/L. Malathion was detected once at 0.01 μg/L. Oil and grease was detected 

three times, with the highest concentration at 5 mg/L. Oil and grease is an indicator that oils and 

petrochemicals are present, but could include thousands of organic compounds, making it difficult to set 

any criteria. Total PCB’s were detected in two of the three samples, at concentrations of 0.12 and 

0.23 μg/L. 

At the new commercial site, six stormwater samples were collected (appendix 1C). Nutrient 

concentrations for total nitrogen ranged from 1.5 to 3.2 mg/L; ammonia plus organic (Kjeldahl) nitrogen, 

0.93 to 2.4 mg/L; total phosphorus, 0.21 to 0.70 mg/L; and dissolved phosphorus, 0.09 to 0.32 mg/L. 

Fecal coliform concentrations ranged from 460 to 10,800 cols/100 mL. Enterococci concentrations 

ranged from 370 to 6,800 cols/100 mL. Cadmium was detected in three samples at concentrations 

ranging from 0.19 to 1.2 mg/L. Lead was detected in all six samples at concentrations ranging from 6.4 

to 45 μg/L, with only one sample exceeding the MCL of 15 μg/L. Mercury was detected twice at 

concentrations of 0.02 and 0.04 μg/L. Diazinon was detected in six samples, ranging in concentration 

from 0.01 to 0.17 μg/L. Malathion was detected once at 0.01 μg/L. Oil and grease was detected four 

times, with the highest concentration at 5 mg/L. Total PCB’s were detected once at the reporting limit of 

0.1 μg/L.

At the residential site, five stormwater samples were collected (appendix 1D). Nutrient 

concentrations for total nitrogen ranged from 2.2 to 4.6 mg/L; ammonia plus organic (Kjeldahl) nitrogen, 
14

1.6 to 4.1 mg/L; total phosphorus, 0.26 to 0.54 mg/L; and dissolved phosphorus, 0.16 to 0.26 mg/L. Fecal 

coliform concentrations ranged from 3,400 to 134,000 cols/100 mL. Enterococci concentrations ranged 

from 440 to 10,600 cols/100 mL. Cadmium was detected in three samples at concentrations less than 

0.70 mg/L. Lead concentrations exceeded the MCL of 15 mg/L in all five samples, ranging from 17 to 

29 mg/L. Mercury was detected at concentrations of 0.06 and 0.07 μg/L. Diazinon was detected in all 

five samples, ranging from 0.18 to 2.7 μg/L; 2.7 μg/L was the maximum concentration detected in 

samples from all sites. Malathion was detected three times at concentrations of 0.02, 0.04, and 0.07 μg/L. 

Oil and grease was detected four times, with the highest concentration at 4 mg/L. No PCB’s were 

detected.

Average Event Mean Concentrations for Selected Properties and Constituents

The average EMC’s of 12 properties and constituents for which estimated annual contaminant 

loads were calculated are listed in table 2. The industrial land-use site had the highest average EMC’s in 

6 of the 12 properties and constituents, with 4 of these being metals. The residential land-use site had 

the highest average EMC’s for total suspended solids, 263 mg/L, and nutrients: total nitrogen, 2.9 mg/L; 

ammonia plus organic nitrogen (Kjeldahl nitrogen), 2.5 mg/L; total phosphorus, 0.44 mg/L; and 

dissolved phosphorus, 0.20 mg/L. The established commercial land-use site had the lowest average 

EMC’s for total suspended solids, 71 mg/L, and nutrients: total nitrogen, 1.4 mg/L; ammonia plus organic 

nitrogen, 1.0 mg/L; total phosphorus, 0.18 mg/L; and dissolved phosphorus, 0.12 mg/L. The average 

dissolved phosphorus concentrations from each land use were two to four times the U.S. Environmental 

Protection Agency criterion of 0.05 milligrams per liter.

Table 2. Average event-mean concentration for selected water-quality properties and constituents for four 

land-use areas within a storm-runoff monitoring network in East Baton Rouge Parish, Louisiana, 

1998-2002

[Concentrations are in milligrams per liter. oC, degrees Celsius; ROE, residue on evaporation; <, less than]

Water-quality property or constituent

Average event-mean concentration

Established 

commercial Industrial

New 

commercial Residential

Chemical oxygen demand 26 45 34 38

Biochemical oxygen demand, 5 day 5.4 6.5 7.7 6.0

Total dissolved solids, ROE at 180oC 47 86 51 46

Total suspended solids, residue at 105oC 71 225 131 263

Nitrogen, total as N 1.4 1.9 2.2 2.9

Nitrogen, ammonia plus organic (Kjeldahl), 

total as N

1.0 1.2 1.6 2.5

Phosphorus, total as P .18 .31 .35 .44

Phosphorus, dissolved as P .12 .13 .15 .20

Cadmium, total recoverable as Cd <.001 .001 <.001 <.001

Copper, total recoverable as Cu .003 .03 .004 .01

Lead, total recoverable as Pb .02 .08 .01 .02

Zinc, total recoverable as Zn .08 .30 .18 .08
15

Estimated Annual Contaminant Load for Selected Properties and Constituents

Estimated annual contaminant loads are listed in table 3. The residential land use is the largest of 

the watersheds (550 acres) where contaminant loads for 8 of the 12 water-quality properties and 

constituents were highest, with 4 of these being nutrients. The established commercial land use is the 

smallest of the watersheds (63 acres), and estimated annual contaminant loads were the lowest of all the 

watersheds. This may indicate that the size of the watershed and runoff from residences with their 

associated contaminants had substantial effects on annual loads within this land use. The industrial 

watershed had the highest estimated annual contaminant loads for metals, followed by the residential land 

use. Zinc had the highest metal load (296 lbs/yr) in the industrial watershed, compared to 194 lbs/yr in the 

residential watershed. However, when comparing yields among each watershed (table 3), the industrial 

watershed had the highest yields for 9 of the 12 properties and constituents, whereas the residential 

watershed had the lowest yields for 7 of the 12. Nutrient yields in the residential watershed were lowest 

for total nitrogen, total phosphorus, and dissolved phosphorus. Metals from the industrial watershed 

yielded more per acre per year than any other watershed. Zinc yields were 2.71 lb/acre/yr in the industrial 

watershed, compared to 0.35 lb/acre/yr in the residential watershed, which was the lowest of all the 

watersheds. Results of the water-quality analyses are listed in appendixes 1A-1D, and the minimum 

detection levels of selected water-quality properties and constituents are listed in appendix 2. 

Table 3. Estimated annual contaminant loads and yields for selected water-quality properties and 

constituents for four land-use areas within a storm-runoff monitoring network in East Baton Rouge Parish, 

Louisiana, 1998-2002

[Loads are in pounds per year. Yields are in pounds per acre per year. oC, degrees Celsius; ROE, residue on evaporation; <, less than]

Water-quality property or 

constituent

Annual loads and yields for watersheds

Established 

commercial Industrial New commercial Residential

Load Yield Load Yield Load Yield Load Yield

Chemical oxygen demand 18,200 289 44,600 409 30,700 196 89,700 163

Biochemical oxygen demand, 

5 day

3,790 60.2 6,410 58.8 6,990 44.5 14,200 25.8

Total dissolved solids, ROE at 

180oC

32,700 519 84,900 779 46,300 295 109,000 198

Total suspended solids, residue

 at 105oC

49,200 781 223,000 2,040 118,000 752 624,000 130

Nitrogen, total as N 1,010 16.0 1,830 16.8 1,990 12.7 6,680 12.2

Nitrogen, ammonia plus organic 

(Kjeldahl), total as N

730 11.6 1,220 11.2 1,430 9.11 5,840 10.6

Phosphorus, total as P 124 1.97 307 2.82 315 2.01 1,040 1.89

Phosphorus, dissolved as P 86 1.37 127 1.16 136 .87 470 .86

Cadmium, total recoverable as Cd <1 <1 1 .009 <1 <1 <1 <1

Copper, total recoverable as Cu 2 .032 31 .28 3 .019 17 .031

Lead, total recoverable as Pb 12 .19 75 .69 13 .083 55 .1

Zinc, total recoverable as Zn 59 .94 296 2.71 163 1.04 194 .35
16

ANALYSIS OF QUALITY-CONTROL DATA

At least one equipment blank for each site was processed with the same detection limits as 

stormwater samples. Results indicated all constituent concentrations were less than reporting limits. A 

replicate sample for trace metals was collected from the new commercial and residential land-use sites 

July 28, 2001. After processing the environmental and replicate samples for the new commercial site, an 

equipment blank was collected from the cone splitter before processing the environmental and replicate 

samples for the residential site. The equipment blank results were less than reporting limits. 

Environmental and replicate analyses are presented in table 4.

Summary

Water was sampled at four watersheds for continued evaluation of urban storm runoff in East Baton 

Rouge Parish, Louisiana, during February 1998 through April 2002. Eighteen samples were collected 

from four watersheds representing land uses characterized predominantly as established commercial, 

industrial, new commercial, and residential. Results of water-quality analyses enabled calculation of 

event-mean concentrations and estimated annual contaminant loads and yields of storm runoff from 

nonpoint sources for 12 water-quality properties and constituents. The following water-quality data are 

reported: physical and chemical-related properties, fecal coliform and enterococci bacteria, major 

inorganic ions, nutrients, trace elements, and organic compounds. 

The frequency of sampling for the selected watersheds was determined by the occurrence of storms. 

Automatic samplers were used to collect samples of storm runoff for each land use for at least the initial 

3 hours of each storm. If the discharge was less than 3 hours, subsamples of the discharge were collected 

until the volume of runoff diminished, or until the level of the stream declined below the sample intake 

line. Manual samples were collected during the first hour and analyzed for specific conductance, field 

pH, water temperature, dissolved oxygen, biochemical oxygen demand, fecal coliform and enterococci 

bacteria, and oil and grease. Due to drought conditions, fewer storms occurred within each watershed, 

causing an unequal distribution of samples collected from each site. 

 The residential land-use site is the largest of the watersheds (550 acres), which resulted in high 

estimated annual contaminant loads in 8 of the 12 water-quality properties and constituents. This may 

indicate that the size of the watershed and runoff from residences with their associated contaminants had 

substantial effects on annual loads within this land use. The industrial land use had the highest estimated 

Table 4. Analysis of quality-control data for two land-use areas in East Baton Rouge Parish, Louisiana, 

July 28, 2001

[<, less than]

Constituent

Concentration (micrograms per liter)

New commercial Residential

Environmental Replicate Environmental Replicate

Cadmium, total recoverable as Cd 1.1 0.48 0.35 0.24

Copper, total recoverable as Cu <20 <20 21 11.3

Lead, total recoverable as Pb 13 12 29 21

Nickel, total recoverable as Ni 5.4 7 4.3 4.5

Zinc, total recoverable as Zn 150 153 133 72
17

annual contaminant loads for metals, followed by the residential land use. Zinc had the highest metal 

load in the industrial land use at 296 pounds per year, compared to 194 pounds per year at the residential 

watershed. However, when comparing yields among each watershed, the industrial watershed had the 

highest yields for 9 of the 12 water-quality properties and constituents, whereas the residential watershed 

had the lowest yield for 7 of the 12. Nutrient yields in the residential watershed were lowest for total 

nitrogen, total phosphorus, and dissolved phosphorus. The industrial watershed yielded more metals per 

acre per year than any other watershed. Zinc yields were 2.71 pounds per acre per year from the industrial 

watershed, compared to 0.35 pounds per acre per year from the residential watershed, which was the 

lowest of all the watersheds. Lead exceeded the U.S. Environmental Protection Agency Maximum 

Contaminant Level of 15 μg/L (micrograms per liter) for drinking water standards in 10 of 18 samples. 

Low level concentrations of mercury were detected twice at both the new commercial and residential 

sites, with all concentrations at or just above reporting limits of 0.02 μg/L. The average dissolved 

phosphorus concentrations from each land use were two to four times the U.S. Environmental Protection 

Agency criterion of 0.05 milligrams per liter. Diazinon, which is widely used as a general-purpose 

insecticide for lawn and gardens, was detected in all 18 samples. The maximum diazinon concentration 

detected, 2.7 μg/L, was from the residential site. Malathion, another insecticide used on lawns, gardens, 

and plants, also was detected at least once from each site, but all concentrations were below the minimum 

detection limit of 0.1 μg/L. 

SELECTED REFERENCES

Britton, L.J., and Greeson, P.E., eds., 1988, Methods for collection and analysis of aquatic biological and 

microbiological samples: U.S. Geological Survey Open-File Report 88-0190, 685 p.

Buchanan, T.J., and Somers, W.P., 1969, Discharge measurements at gaging stations: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 3, chap. A8, 65 p.

DeLorme Mapping, 1993, Map Expert, version 2: Freeport, Maine, DeLorme Mapping.

Demcheck, D.K., Frederick C.P., Johnson, K.L., 1998, Water-quality characteristics of urban storm runoff 

at selected sites in East Baton Rouge Parish, Louisiana, April 1993 through June 1995: U.S. Geological 

Survey Open-File Report 98-565, 59 p.

Fishman, M.J., and Friedman, L.C., eds., 1989, Methods for determination of inorganic substances in water 

and fluvial sediments: U.S. Geological Survey Techniques of Water-Resources Investigations, book 5, 

chap. A1, 545 p.

Makepeace, D.K., Smith, D.W., and Stanley, S.J., 1995, Urban stormwater quality—Summary of 

contaminant data, in Critical reviews: Environmental Science and Technology, v. 25, no. 2, p. 93-139.

National Oceanic and Atmospheric Administration Climate Prediction Center, 2002, Drought monitoring, 

past Palmer Drought Severity Index maps by week for 1998-2001: accessed August 13, 2002, at URL 

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer/1998-2001

Rantz, S.E., and others, 1982, Measurement and computation of streamflow, volume 2. Computation of 

discharge: U.S. Geological Survey Water-Supply Paper 2175, 347 p.
18

Schueler, T.R., 1987, Controlling urban runoff—A practical manual for planning and designing urban 

BMP’s: Washington, D.C., Department of Environmental Programs, Metropolitan Washington Council 

of Governments [variously paged].

U.S. Census Bureau, 2002, State and county quick facts: accessed July 12, 2002, at URL

http://www.quickfacts.census.gov

U.S. Environmental Protection Agency, 1979, Purgeables—Method 624: Federal Register, v. 44, no. 223, 

p. 69532.

—— 1986, Quality criteria for water 1986: Washington, D.C., U.S. Environmental Protection Agency 

440/5-86-00/1 [variously paged].

—— 1991, Guidance manual for the preparation of part 1 of the NPDES permit applications for discharges 

from municipal separate storm sewer systems: Washington, D.C., 160 p.

—— 1992, Guidance manual for the preparation of part 2 of the NPDES permit applications for discharges 

from municipal separate storm sewer systems: Washington, D.C., 158 p.

—— 1997, Application to Discharge to Waters of the United States Permit No. LAS000101-- Baton Rouge 

Municipal Separate Storm Sewer System (MS4) Permit [variously paged].

Weibel, S.R., Anderson, R.J., and Woodward, R.L., 1964, Urban land run-off as a factor in stream pollution: 

Water Pollution Control Federation Journal, v. 36, no. 7, p. 914-924.

Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, L.E., eds., 1987, Methods for the determination of 

organic substances in water and fluvial sediments: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. A3, 80 p.

Wilbur Smith Associates, 1992, Existing and future land use analysis for NPDES stormwater permit 

applications: Baton Rouge, La., Prepared for Department of Public Works, 27 p.
19

APPENDIXES: RUNOFF AND WATER-QUALITY DATA

1. Runoff and Water-Quality Data

1A-1D. Summary of runoff and water-quality data from a drainage canal at:

1A. Lobdell Boulevard in an established commercial land-use area, 

Baton Rouge, Louisiana during selected storms, 

February 15, 1998-May 10, 1999

1B. Tom Drive in an industrial land-use area, Baton Rouge, 

Louisiana, during selected storms, February 15, 1998-May 10, 1999

1C. Sunbelt Court in a new commercial land-use area, 

Baton Rouge metropolitan area, Louisiana, during selected

 storms, July 24, 1998-April 8, 2002

1D. Goodwood Boulevard in a residential land-use area, 

Baton Rouge, Louisiana, during selected storms, 

July 22, 1998-April 8, 2002

2. Minimum detection levels of water-quality properties and constituents
20

Appendix 1A. Summary of runoff and water-quality data from a drainage canal at Lobdell Boulevard in an established commercial landuse area, Baton Rouge, Louisiana, during selected storms, February 15, 1998-May 10, 1999

[--, no data; <, less than]

Water-quality property or constituent

Beginning date of storm

2-15-98 8-14-98 10-6-98 5-10-99

Runoff volume

Discharge (cubic feet) 142,300 227,300 258,200 310,000

Specific conductance

Specific conductance (microsiemens per centimeter at 25 degrees Celsius) 35 41 120 48

pH and alkalinity

pH (standard units) 6.9 6.7 7.9 6.8Alkalinity, laboratory, as calcium carbonate (milligrams per liter) 7.2 19 47 8.4

Temperature

Temperature, water (degrees Celsius) 13.0 26.0 27.0 21.0

Dissolved oxygen and oxygen demand (milligrams per liter)

Dissolved oxygen 7.0 8.6 6.5 8.5Chemical oxygen demand 17 13 19 56Biochemical oxygen demand, 5-day 1.5 8.4 4.3 7.5

Fecal indicator bacteria (colonies per 100 milliliters)

Fecal coliform, 0.65-micrometer filter 1,100 a100,000 9,600 b--

Enterococci, 0.45-micrometer filter 5,000 4,930 5,000 b--

Dissolved and suspended solids (milligrams per liter)

Total dissolved solids, residue on evaporation at 180 degrees Celsius 28 20 84 55

Suspended solids, residue at 105 degrees Celsius 35 146 58 43

Nutrients (milligrams per liter)

Nitrogen, total as N .73 1.4 1.4 2.3Nitrogen, ammonia plus organic (Kjeldahl), total as N .43 1.1 .95 1.7Phosphorus, total as P .06 .12 .31 .22Phosphorus, dissolved as P .03 .04 .22 .20

Trace metals (micrograms per liter)

Cadmium, total recoverable as Cd 1.28 <1 <1 <1Chromium, total recoverable as Cr <5 <5 <5 <5Copper, total recoverable as Cu <10 <10 13 <10

Lead, total recoverable as Pb 14 40 5.7 11

Mercury, total recoverable as Hg <.1 <.1 <.1 <.1Nickel, total recoverable as Ni 1.2 3.4 3.4 2.2Zinc, total recoverable as Zn 47 91 91 109

Organic compounds

Oil and grease, total recoverable, gravimetric (milligrams per liter) <1 <1 <1 <1Pesticides (micrograms per liter)

Diazinon, total .01 .79 .03 .68Malathion, total .01 .01 <.01 <.01

Polychlorinated biphenyls, total (micrograms per liter) .12 .2 <.1 <.1

aResults based on colony count outside the acceptable range (non-ideal colony count).bAnalysis for bacteria from the May 10, 1999, storm was unsuccessful due to incubation problems. 
21

Appendix 1B. Summary of runoff and water-quality data from a drainage canal at Tom Drive in an industrial land-use 

area, Baton Rouge, Louisiana, during selected storms, February 15, 1998-May 10, 1999

[--, no data; <, less than]

Water-quality property or constituent

Beginning date of storm

2-15-98 8-14-98 5-10-99

Runoff volume

Discharge (cubic feet) 470,000 308,100 461,500

Specific conductance

Specific conductance (microsiemens per centimeter at 25 degrees Celsius) 266 70 105

pH and alkalinity

pH (standard units) 7.8 7.8 8.2Alkalinity, laboratory, as calcium carbonate (milligrams per liter) 92 33 52

Temperature

Temperature, water (degrees Celsius) 13.0 25.0 22.0

Dissolved oxygen and oxygen demand (milligrams per liter)

Dissolved oxygen 7.1 8.6 7.9Chemical oxygen demand 45 17 73Biochemical oxygen demand, 5-day 5.3 8.5 5.5

Fecal indicator bacteria (colonies per 100 milliliters)

Fecal coliform, 0.65-micrometer filter 520 a80,000 b--

Enterococci, 0.45-micrometer filter 630 2,200 b--

Dissolved and suspended solids (milligrams per liter)

Total dissolved solids, residue on evaporation at 180 degrees Celsius 108 51 98

Suspended solids, residue at 105 degrees Celsius 186 324 165

Nutrients (milligrams per liter)

Nitrogen, total as N 1.2 1.8 2.6Nitrogen, ammonia plus organic (Kjeldahl), total as N .71 1.3 1.7Phosphorus, total as P .15 .31 .47Phosphorus, dissolved as P .04 .12 .22

Trace metals (micrograms per liter)

Cadmium, total recoverable as Cd 2.5 1.2 <1Chromium, total recoverable as Cr <5 <5 <5Copper, total recoverable as Cu 26 34 33Lead, total recoverable as Pb 75 78 75Mercury, total recoverable as Hg <.1 <.1 <.1Nickel, total recoverable as Ni 170 32 801Zinc, total recoverable as Zn 236 364 297

Organic compounds

Oil and grease, total recoverable, gravimetric (milligrams per liter) 3 5 4Pesticides (micrograms per liter)

Diazinon, total .07 .17 .05Malathion, total .01 <.01 <.01

Polychlorinated biphenyls, total (micrograms per liter) .12 .23 <.1

aResults based on colony count outside the acceptable range (non-ideal colony count).bAnalysis for bacteria from the May 10, 1999, storm was unsuccessful due to incubation problems. 
22

Water-quality property or constituent

Beginning date of storm

7-24-98 10-6-98 3-2-99 9-1-99 7

Runoff volume

Discharge (cubic feet) 487,000 136,000 459,000 159,000 3

Specific conductance

Specific conductance (microsiemens per centimeter at 25 degrees Celsius) 51 212 103 86 

pH and alkalinity

pH (standard units) 7.5 8.6 7.9 7.4 Alkalinity, laboratory, as calcium carbonate (milligrams per liter) 18 81 52 26 

Temperature 

Temperature, water (degrees Celsius) 30.5 26.0 17.0 32.0 

Dissolved oxygen and oxygen demand (milligrams per liter)

Dissolved oxygen 6.6 5.6 7.9 6.5 Chemical oxygen demand 14 25 78 22 Biochemical oxygen demand, 5-day 6.5 5.6 11.2 8.7 

Fecal indicator bacteria (colonies per 100 milliliters)

Fecal coliform, 0.65-micrometer filter 460 10,800 3,400 3,400 Enterococci, 0.45-micrometer filter 6,130 6,800 1,200 370 

Dissolved and suspended solids (milligrams per liter)

Total dissolved solids, residue on evaporation at 180 degrees Celsius 41 104 20 54 

Suspended solids, residue at 105 degrees Celsius 92 54 250 95 

Nutrients (milligrams per liter)

Nitrogen, total as N 1.5 1.8 2.7 1.6 Nitrogen, ammonia plus organic (Kjeldahl), total as N .95 1.4 2.4 .93 Phosphorus, total as P .24 .45 .70 .22 Phosphorus, dissolved as P .15 .32 .11 .13 

Trace metals (micrograms per liter)

Cadmium, total recoverable as Cd <1 <1 1.2 <1 Chromium, total recoverable as Cr <5 <5 <5 <5 Copper, total recoverable as Cu <10 <10 21 E7 Lead, total recoverable as Pb 8.9 6.6 45 7 Mercury, total recoverable as Hg <.1 <.1 <.1 <.1 Nickel, total recoverable as Ni 3.5 3.2 11 5 Zinc, total recoverable as Zn 124 107 506 106 

Organic compounds

Oil and grease, total recoverable, gravimetric (milligrams per liter) 2 4 2 <1 Pesticides (micrograms per liter)

Diazinon, total .04 .02 .03 .04 Malathion, total <.01 <.01 <.01 .01 

Polychlorinated biphenyls, total (micrograms per liter) <.1 .1 <.1 <.1 

Appendix 1C. Summary of runoff and water-quality data from a drainage canal at Sunbelt Court in a new commercial land-use area, Ba

Louisiana, during selected storms, July 24, 1998-April 8, 2002

[E, estimated; <, less than]
23

Water-quality property or constituent

Beginning date of storm

7-22-98 11-10-98 10-8-99 7-28-01 

Runoff volume

Discharge (cubic feet) 400,000 165,900 398,700 856,500 4

Specific conductance

Specific conductance (microsiemens per centimeter at 25 degree Celsius) 48 71 33 29 

pH and alkalinity

pH (standard units) 7.1 7.1 7.0 6.7 Alkalinity, laboratory, as calcium carbonate (milligrams per liter) 12 22 12 5.9 

Temperature

Temperature, water (degrees Celsius) 29.0 20.0 21.5 26.5 

Dissolved oxygen and oxygen demand (milligrams per liter)

Dissolved oxygen 6.5 8.6 8.2 6.7 Chemical oxygen demand 17 <10 50 64 Biochemical oxygen demand, 5-day 2.3 7.1 7.2 6.7 

Fecal indicator bacteria (colonies per 100 milliliters)

Fecal coliform, 0.65-micrometer filter a10,200 29,000 3,400 b134,000 

Enterococci, 0.45-micrometer filter a10,600 3,500 440 480 

Dissolved and suspended solids (milligrams per liter)

Total dissolved solids, residue on evaporation at 180 degrees Celsius 50 65 28 40 

Suspended solids, residue at 105 degrees Celsius 122 298 336 225 

Nutrients (milligrams per liter)

Nitrogen, total as N 2.2 2.6 2.7 2.6 Nitrogen, ammonia plus organic (Kjeldahl), total as N 1.6 2.0 2.4 2.2 Phosphorus, total as P .26 .40 .48 .54 Phosphorus, dissolved as P .16 .18 .19 .20 

Trace elements (micrograms per liter)

Cadmium, total recoverable as Cd <1 <1 .69 .35 Chromium, total recoverable as Cr <5 <5 <5 <5 Copper, total recoverable as Cu <10 <10 <20 21 Lead, total recoverable as Pb 17 28 17 29 Mercury, total recoverable as Hg <.1 <.1 <.3 .06 Nickel, total recoverable as Ni 4.3 3.1 3.5 4.3 Zinc, total recoverable as Zn 41 74 85 133 

Organic compounds

Oil and grease, total recoverable, gravimetric (milligrams per liter) 2 4 2 3 Pesticides (micrograms per liter)

Diazinon, total .18 .65 .59 .33 Malathion, total .02 <.02 .04 <.03 

Polychlorinated biphenyls, total (micrograms per liter) <.1 <.1 <.1 <.1 

aResults based on colony count outside the acceptable range (non-ideal colony count). bResults based on a 1:100 dilution.cResults based on a 1:10 dilution.

Appendix 1D. Summary of runoff and water-quality from a drainage canal at Goodwood Boulevard in a residential land-use area, Baton 

selected storms, July 22, 1998-April 8, 2002

[E, estimated; <, less than]
24

Water-quality property or constituent Minimum detection level

Specific conductance

Specific conductance (microsiemens per centimeter at 25 degrees Celsius) 1

pH and alkalinity

pH, laboratory (standard units) 0.1

Alkalinity, laboratory, as calcium carbonate (milligrams per liter) 1

Oxygen demand (milligrams per liter)

Chemical oxygen demand 10

Dissolved and suspended solids (milligrams per liter)

Total dissolved solids, residue on evaporation at 180 degrees Celsius 1

Suspended solids, residue at 105 degrees Celsius 1

Nutrients (milligrams per liter)

Nitrogen, total as N .05

Nitrogen, ammonia plus organic (Kjeldahl), total as N .2

Phosphorus, total as P .01

Phosphorus, dissolved as P .01

Trace metals (micrograms per liter)

Cadmium, total recoverable as Cd 1

Chromium, total recoverable as Cr 5

Copper, total recoverable as Cu 5

Lead, total recoverable as Pb 1

Mercury, total recoverable as Hg .02

Nickel, total recoverable as Ni 1

Zinc, total recoverable as Zn 10

Organic compounds

Oil and grease, total recoverable, gravimetric (milligrams per liter) 1

Pesticides (micrograms per liter)

Diazinon, total .02

Malathion, total .1

Polychlorinated biphenyls, total (micrograms per liter) .1

Appendix 2. Minimum detection levels of water-quality properties and constituents