Water-Quality Changes and Organic-Carbon 

Characterization During Recharge with 

Recycled Water at a Research Basin in 

Montebello Forebay, Los Angeles County, 

California, 1991–1996

Edited by Roy A. Schroeder

Sacramento, California 

2003

Water-Resources Investigations Report 03-4146

U.S. GEOLOGICAL SURVEY

Prepared in cooperation with the

WATER REPLENISHMENT DISTRICT OF SOUTHERN CALIFORNIA 5025-50
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 write to:

District Chief

U.S. Geological Survey

Placer Hall, Suite 2012

6000 J Street

Sacramento, CA 95819-61292

http://ca.water.usgs.gov
Preface iii

Water-Quality Changes and Organic-Carbon 

Characterization During Recharge with Recycled Water 

at a Research Basin in Montebello Forebay, Los Angeles 

County, California, 1991–1996

Edited by Roy A. Schroeder

Contributing Authors: Robert Anders, Larry B. Barber, Jerry A. Leenheer, Ted I. Noyes, 

Ronald R. Rathbun, Terry F. Rees, Colleen A. Rostad, Roy A. Schroeder, Kevin A. Thorn, and

Steven J. Younger

PREFACE

 The demand that population growth is placing 

on water resources provides an impetus for increasing 

use of “recycled” or “reclaimed” wastewater to 

augment water supplies, especially in the arid 

southwestern United States. The Central GroundWater Basin (Central Basin) in south-central Los 

Angeles County, California, is an area in which 

recharge has been augmented using wastewater 

(currently subjected to tertiary treatment that includes 

chlorination-dechlorination and dual-media filtration) 

at large infiltration basins in the Montebello Forebay 

for the past 40 years. This area presents an opportunity 

to study water-quality changes during infiltration and 

subsurface transport of recycled water over short and 

long timescales and distances. A small research basin 

was constructed in the Montebello Forebay to develop 

analytical methods and investigate processes that occur 

during recharge of recycled water over distances as 

great as a few tens of feet and ground-water traveltimes 

ranging to several days. The results from investigations 

by the U.S. Geological Survey (USGS) between 1992 

and 1995 are presented in 12 topical chapters in two 

parts by various authors herein. Results from later 

investigations that extend farther downgradient for 

distances of several miles and traveltimes of several 

decades have been presented at several scientific 

conferences and in publications by Anders and 

Schroeder (1997), Barber and others (1997), Schroeder 

and others (1997), Leenheer and others (2001), and 

Schroeder and Anders (2002), and in a companion 

publication to this report to be published later this year.
iv Preface

A brief introduction to the study in Chapter 1 is 

followed by a description of the constructed basin and 

its instrumentation in Chapter 2. Chapter 3 contains a 

short description of the geohydrology in the study area: 

a USGS report by Reichard and others (2003) provides 

greater detail. Chapter 4 describes microbial changes 

that occur beneath the basin as a result of recharge with 

recycled water. As expected, organisms capable of 

oxidizing and reducing nitrogen were found to be 

abundant, insofar as they occur naturally in the soil as 

well as in wastewater. Transport of fecal coliform and 

algae downward through the soil beneath the basin 

floor was noted, and that result led to the recent 

initiation of studies on virus transport at the 

constructed basin using bacteriophage. Chapter 5 

summarizes the attenuation that occurs in aqueous 

concentration for a number of inorganic constituents 

and organic carbon beneath the basin as recycled water 

percolates downward. Reduction in concentration of 

total dissolved nitrogen ranged from about 20 to about 

60 percent and was determined to be dependent on 

timing and duration of wetting and drying cycles 

during recharge, with conditions that produce the 

establishment of longer periods of anoxia favoring 

greater removal by denitrification. The reduction in 

concentration of dissolved organic carbon (DOC) was 

about one-third and was not dependent on operating 

conditions that affect redox status in the subsurface, 

such as duration of wet and dry cycles and thickness of 

the unsaturated zone, which did affect nitrogen 

removal. Much of the material in Chapters 4 and 5 is 

from a Master’s thesis by Anders (1997) and also has 

been summarized by Anders and Schroeder (1997).

 The seven remaining chapters comprise part II 

of this report and describe changes in organic carbon as 

recycled water percolates beneath the constructed 

basin. Chapter 6 presents the framework in which this 

part of the study was conducted and includes broad 

characterization of organic matter as defined 

operationally by the analytical methodologies as well 

as the identification of specific organic compounds. In 

Chapter 7, the authors use element ratios and nuclear 

magnetic resonance (NMR) spectrometry to conclude 

that organic matter in colloids is derived primarily from 

bacteria and that organic content of colloidal material 

decreases as mineral (aluminosilicate) content 

increases with increasing subsurface depth. Chapter 8 

details the characterization of DOC by sorption on ionexchange resins. Only a small shift in composition was 

observed in profiles of various organic fractions 

beneath the basin as the concentration of all fractions 

declines in concert with the decrease in DOC with 

depth. Chapter 9 describes the use of infrared (IR) and 

ultraviolet/visible (UV/VIS) spectrometry to 

characterize the DOC at a structural level and shows 

the abundant presence and persistence of surfactants 

and their metabolites in recycled water beneath the 

basin—a result that is confirmed by NMR spectometry 

in Chapter 10. The methods described in Chapters 8, 9, 

and 10 form the analytical foundation for later work 

described by Leenheer and others (2001) that 

demonstrated the persistence of surfactant metabolites, 

even after nearly 30 years and transport over several 

miles in the aquifer. Transport and fate of halogenated 

organic compounds resulting from the chlorination of 

recycled water are described in Chapter 11. Perhaps the 

most important finding in this chapter is that the 

trihalomethane (THM) formation potential of organic 

carbon in recycled water is lower than in natural 

organic carbon from most surface-water sources. 

Chapter 12 presents the results of gas chromatographymass spectrometry (GC/MS) analysis for several 

specific organic compounds as part of an effort to find a 

compound that could serve as a conservative (is not 

sorbed or degraded) tracer for recycled water in ground 

water and is not naturally present. To date, no such 

compound suitable over long distances and traveltimes 

has been found that can serve as an independent 

verification on inorganic constituents, such as chloride 

and boron, that are elevated in recycled water but do 

occur naturally.

The results presented here document the 

attenuation in nitrogen and organic carbon in recycled 

water, sometimes referred to as “polishing,” during the 

early stages by soil aquifer treatment that is sought by 

water regulators and purveyors; but are generally 

unable to answer the question of long-term 

sustainability and to what extent removal is due to 

temporary storage on the soils. For that reason, the 

study was extended following completion of this work 

to include downgradient public-supply wells and 

multilevel monitoring wells where reclaimed water that 

originated many years ago is present. The work 

described in these 12 chapters contributed to the 

development of methods used in the subsequent 

investigations.
Contents v

TABLE OF CONTENTS

Preface.................................................................................................................................................................. i

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

Part I ..................................................................................................................................................................... 2

Chapter 1: Introduction ........................................................................................................................................ 2

By Roy A. Schroeder and Robert Anders

Purpose and Scope ...................................................................................................................................... 5

Acknowledgments....................................................................................................................................... 5

Chapter 2: Research Basin Construction and Instrumentation............................................................................. 6

By Terry F. Rees and Robert Anders 

Chapter 3: Geologic and Hydrologic Setting ....................................................................................................... 13

By Robert Anders and Roy A. Schroeder

Lithology ..................................................................................................................................................... 13

Vertical Hydraulic Conductivity ................................................................................................................. 15

Horizontal Hydraulic Conductivity............................................................................................................. 19

Hydraulic Conditions During the Recharge Experiments........................................................................... 19

Chapter 4: Microbiological Changes During Recharge ....................................................................................... 22

By Robert Anders and Roy A. Schroeder

Methods....................................................................................................................................................... 22

Bacterial Distributions in Cores.................................................................................................................. 23

Total and Fecal Coliform in Water ............................................................................................................. 24

Nitrogen-Transforming Bacteria in Water.................................................................................................. 25

Chapter 5: Changes in Common Chemical Constituents During Recharge......................................................... 28

By Roy A. Schroeder and Robert Anders

Methods for Common Chemical Constituents............................................................................................ 28

Chemical Attenuation During Recharge ..................................................................................................... 29

Mixing and Displacement During Recharge...................................................................................... 29

Nitrogen ............................................................................................................................................. 33

Organic Carbon .................................................................................................................................. 35

Zinc .................................................................................................................................................... 35

Arsenic ............................................................................................................................................... 35

Chemical and Isotopic Evidence for Denitrification................................................................................... 37

Other Possible Mechanisms for Nitrogen Removal.................................................................................... 50

Volatilization...................................................................................................................................... 51

 Ion Exchange..................................................................................................................................... 51

Sorption.............................................................................................................................................. 52

Relative Importance of Oxygen and Nitrate as Electron Acceptors ........................................................... 54

Part II.................................................................................................................................................................... 57

Chapter 6: Hierarchal Approach to Organic Matter Characterization ................................................................. 57

By Jerry A. Leenheer and Larry B. Barber

Chapter 7: Isolation and Characterization of Colloids......................................................................................... 61

By Kevin A. Thorn, Colleen E. Rostad, and Ted I. Noyes

Sampling and Methods................................................................................................................................ 61

Colloid Isolation Procedures.............................................................................................................. 61

Analytical Methods ............................................................................................................................ 61

Results and Discussion................................................................................................................................ 62
vi Contents

Colloid Concentration and Changes in Elemental Composition ....................................................... 62

Nuclear Magnetic Resonance Spectrometry ...................................................................................... 64

Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular 

Weight Determinations ........................................................................................................................................ 78

By Larry B. Barber

Methods....................................................................................................................................................... 78

Sample Collection and Field Processing............................................................................................ 78

Analytical Methods ............................................................................................................................ 78

Total and Dissolved Organic and Inorganic Carbon Concentration......................................... 78

Dissolved Organic Carbon Fractionation.................................................................................. 79

Dissolved Organic Carbon Molecular-Weight Characterization.............................................. 79

Results and Discussion................................................................................................................................ 80

First Recharge Experiment................................................................................................................. 80

Organic Carbon Concentration ................................................................................................. 80

Dissolved Organic Carbon Fractionation.................................................................................. 80

Second Recharge Experiment ............................................................................................................ 82

Organic Carbon Concentration ................................................................................................. 82

Molecular Weight of Dissolved Organic Carbon ..................................................................... 84

Dissolved Organic Carbon Fractionation.................................................................................. 85

Third Recharge Experiment ............................................................................................................... 87

Organic Carbon Concentration ................................................................................................. 87

Molecular Weight of Dissolved Organic Carbon ..................................................................... 88

Dissolved Organic Carbon Fractionation.................................................................................. 88

Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry.... 89

By Jerry A. Leenheer and Ted I. Noyes

Fractionation and Isolation Methods........................................................................................................... 89

Infrared Spectral Characterizations............................................................................................................. 90

Ultraviolet/Visible Spectrometry ................................................................................................................100

Chapter 10: Characterization of Dissolved Organic Matter by Nuclear Magnetic Resonance

(NMR) Spectrometry............................................................................................................................................102

By Kevin A. Thorn and Steven J. Younger

Sampling .....................................................................................................................................................102

Results.........................................................................................................................................................102

Chapter 11: Distributions of Halogenated Organic Compounds .........................................................................109

By Colleen E. Rostad and Ronald E. Rathbun

Methods.......................................................................................................................................................109

Results.........................................................................................................................................................110

Chapter 12: Specific Organic Contaminants........................................................................................................116

By Larry B. Barber and Colleen E. Rostad

Sampling .....................................................................................................................................................116

Analytical Methods .....................................................................................................................................116

Methylene Blue Active Substances....................................................................................................116

Anionic Surfactants............................................................................................................................116

Caffeine..............................................................................................................................................117

Volatile Organic Compounds.............................................................................................................118

Results.........................................................................................................................................................118

April 1994 Sampling..........................................................................................................................118

Methylene Blue Active Substances ..........................................................................................118

Linear Alkylbenzene Sulfonate.................................................................................................118

Caffeine.....................................................................................................................................118
Contents vii

September 1994 Sampling .................................................................................................................118

Linear Alkylbenzene Sulfonate.................................................................................................118

Caffeine.....................................................................................................................................120

Volatile Organic Compounds ...................................................................................................120

References Cited ..................................................................................................................................................123

Appendixes...........................................................................................................................................................129
viii Figures

FIGURES

Figure 1. Map showing location of the research basin study area in Montebello Forebay, Los Angeles 

County, California.............................................................................................................................. 3

Figure 2. Map showing location of the U.S. Geological Survey/Water Replenishment District of 

Southern California research basin in Pico Rivera, Los Angeles County, California ....................... 4

Figure 3. Maps and photograph showing location of instrumentation sites at the U.S. Geological 

Survey/Water Replenishment District of Southern California research basin, Montebello 

Forebay, Los Angeles County, California ......................................................................................... 7

Figure 4. Schematoc showing sampling instrumentation at the U.S. Geological Survey/Water 

Replenishment District of Southern California research basin, Montebello Forebay, 

Los Angeles County, California......................................................................................................... 8

Figure 5. Graph showing hydrogeologic section of the Montebello Forebay area, Los Angeles County, 

California ........................................................................................................................................... 14

Figure 6. Graph showing grain-size distribution for core material collected from selected depths at 

PR10 beneath the research basin, Montebello Forebay, Los Angeles County, California ................ 17

Figure 7. Graphs showing electromagnetic induction and natural gamma radiation logs at PR8 and 

PR10 below research basin, Montebello Forebay, Los Angeles County, California......................... 18

Figure 8. Graph showing vertical hydraulic conductivity of core material from selected depths beneath

the research basin, Montebello Forebay, Los Angeles County, California ....................................... 20

Figure 9. Graph showing depth and altitude of water level at the research basin, Montebello Forebay, 

Los Angeles County, California, January 1993–December 1995...................................................... 21

Figure 10. Graph showing distribution of nitrate-reducing and denitrifying bacteria at the research basin,

Montebello Forebay, Los Angeles County, California, during recharge experiments (data

from PR12 at surface, multilevel sampler at 4 to 20 feet, PR9 at 25 feet, and PR8 at 50 feet) ......... 27

Figure 11. Graph showing effect of recycled water on ground-water composition at the research basin, 

Montebello Forebay, Los Angeles County, California ...................................................................... 30

Figure 12. Graphs showing displacement of preexisting chloride at multilevel samplers (MLS, at indicated

depths in feet) and piezometers (PR9 and 11, above the clay lens; PR8, below the clay lens)

beneath the research basin, Montebello Forebay, Los Angeles County, California, as the

basin is filled with recycled water for the periods up to (A) 17 days and (B) during the

subsequent drying cycle ..................................................................................................................... 32

Figure 13. Graph showing displacement of preexisting water (day 0) beneath the research basin, 

Montebello Forebay, Los Angeles County, California, as the research basin is filled 

with recycled water and then its return to prior isotopic composition about 6 weeks 

after recharge is discontinued (day 58) .............................................................................................. 33

Figure 14. Graph showing removal of nitrogen beneath the research basin, Montebello Forebay, 

Los Angeles County, California, as the research basin is filled with recycled water 

(MLS4–20, average for multilevel sampler; PR9 and 11, average for piezometers

above the clay lens)............................................................................................................................ 34

Figure 15. Graph showing change in dissolved organic carbon concentrations beneath the research basin, 

Montebello Forebay, Los Angeles County, California, before (day 0), during (day 2), and

after (day 58) recharge with recycled water....................................................................................... 36

Figure 16. Graph showing removal of zinc beneath the research basin, Montebello Forebay, Los Angeles 

County, California, as the research basin is filled with recycled water ............................................. 37

Figure 17. Graph showing changes in ammonia (NH4-N) and nitrate (NO3-N) concentrations in 

recycled water in the research basin (PR12) and from 5 feet beneath the floor of the

research basin, Montebello Forebay, Los Angeles County, California, during the second

recharge experiment that began in April 1994................................................................................... 39
Figures ix

Figure 18. Graphs showing changes in concentration and distribution of nitrogen species in the research 

basin, Montebello Forebay, Los Angeles County, California, as the research basin is filled 

with recycled water for 17 days: A, before recharge; B, 0.5 day after recharge began; 

C, 1 day after recharge began; D, 2 days; E, 3 days; F, 4 days; G, 17 days (last day of 

recharge); H, 58 days (41 days after recharge discontinued)............................................................. 40

Figure 19. Graph showing changes in dissolved-manganese concentration beneath the research basin, 

Montebello Forebay, Los Angeles County, California, during recharge with recycled water .......... 48

Figure 20. Graph showing changes in dissolved-oxygen concentration beneath the research basin, Montebello 

Forebay, Los Angeles County, California, at selected times during the recharge experiment.......... 49

Figure 21. Graph showing progress toward reequilibration of dissolved barium (Ba), strontium (Sr), and 

lithium (Li) beneath the research basin, Montebello Forebay, Los Angeles County, 

California, on the 3rd (April 7, 1994) and 17th (April 21) days of recharge with recycled water .... 53

Figure 22. Graph showing removal of orthophosphate from recycled water beneath the research basin, 

Montebello Forebay, Los Angeles County, California, on the 3rd (April 7, 1994) 

and 17th (April 21) days of recharge ................................................................................................. 55

Figure 23. Diagram showing hierarchal classification of dissolved organic carbon ........................................... 58

Figure 24. Diagram showing chemical structure of selected organic compounds and functional groups........... 59

Figure 25A. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from PR13, April 1994................................................. 65

Figure 25B. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear 

magnetic resonance spectometry of colloid collected from MLS4, April 1994................................ 66

Figure 25C. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from MLS7, April 1994................................................ 67

Figure 25D. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic

resonance spectometry of colloid collected from PR9, April 1994................................................... 68

Figure 25E. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic

resonance spectometry of colloid collected from PR12, September 1994 ........................................ 69

Figure 25F. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from PR9, September 1994 .......................................... 70

Figure 25G. Graph showing nitrogen-15 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from PR13, April 1994................................................. 71

Figure 25H. Graph showing nitrogen-15 cross polarization/magic-angle spinning nuclear magnetic

resonance spectometry of colloid collected from PR12, September 1994 ........................................ 72

Figure 25I. Graph showing dipolar dephased carbon-13 cross polarization/magic-angle spinning

nuclear magnetic resonance spectometry of colloid collected from PR12, September 1994............ 73

Figure 25J. Graph showing carbon-13 cross polarization/magic-angle spinning nuclear magnetic

resonance spectometry of colloid from Thoreau’s Bog..................................................................... 74

Figure 25K. Graph showing phosphorus-31 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from PR12, September 1994 ........................................ 75

Figure 25L. Graph showing phosphorus-31 cross polarization/magic-angle spinning nuclear magnetic 

resonance spectometry of colloid collected from PR9, September 1994 .......................................... 76

Figure 26. Graph showing relative proportions of six dissolved organic carbon fractions at the research 

basin, Montebello Forebay, Los Angeles County, California, during the August 1993 recharge 

experiment ......................................................................................................................................... 81

Figure 27. Graph showing relative concentrations of six dissolved organic carbon fractions in PR13 

(effluent depicted as zero depth) and beneath the research basin during the April 1994

recharge experiment, Montebello Forebay, Los Angeles County, California ................................... 86

Figure 28. Graph showing infrared spectra of dissolved organic carbon (DOC) fractions from reclaimedwater effluent (PR13) sampled April 5, 1994, at the research basin, Montebello Forebay,

Los Angeles County, California ........................................................................................................ 92
x Figures

Figure 29. Graph showing infrared spectra of dissolved organic carbon (DOC) fractions in reclaimed 

water sampled from the research basin (PR12) September 21, 1994, Montebello Forebay,

Los Angeles County, California ........................................................................................................ 93

Figure 30. Graph showing infrared spectra of dissolved organic carbon (DOC) fractions from water 

sampled from well PR11 September 19, 1994, at the research basin, Montebello Forebay, 

Los Angeles County, California ........................................................................................................ 94

Figure 31. Graph showing infrared spectra of natural fulvic acid, protein, and pyrimidine................................ 96

Figure 32. Graph showing infrared spectra of synthetic aromatic sulfonate surfactants and a sulfophenyl

carboxylate (SPC) metabolite ............................................................................................................ 97

Figure 33. Graph showing infrared spectra of synthetic alkylphenol polyethoxylate surfactants and 

certain metabolites ............................................................................................................................. 98

Figure 34. Graph showing infrared spectra of hydrophobic neutral fractions for samples collected 

April 5, 1994, from the research basin (PR12); April 5 from MLS4; and April 8 from 

well PR9 (spectra A to C, respectively), Montebello Forebay, Los Angeles County, 

California ........................................................................................................................................... 99

Figure 35. Graph showing ultraviolet/visible (UV/VIS) spectrum of blue dye subfraction isolated 

from a sample collected September 20, 1994, from well PR9, research basin, 

Montebello Forebay, Los Angeles County, California......................................................................101

Figure 36. Graph showing continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance 

spectra of April 1994 PR12 fulvic-acid fraction and Minnesota ground-water fulvic-acid 

fraction ...............................................................................................................................................103

Figure 37. Graph showing continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance 

spectrum of April 1994 PR12 fulvic-acid fraction showing chemical shift assignments

of surfactants......................................................................................................................................105

Figure 38. Graph showing continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance

spectrum of April 1994 PR9 fulvic-acid fraction ..............................................................................106

Figure 39. Graph showing continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance 

spectrum of September 1994 PR12 fulvic-acid fraction....................................................................107

Figure 40. Graph showing continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance

spectrum of September 1994 PR9 fulvic-acid fraction......................................................................108

Figure 41. Graph showing concentrations of trihalomenthane (THM) and total organic halides 

(TOX) for selected samples collected in April 1994 at the research basin, Montebello

Forebay, Los Angeles County, California .........................................................................................112

Figure 42. Graph showing concentrations of trihalomenthane (THM) and total organic halides 

(TOX) for selected samples collected in September 1994 at the research basin, 

Montebello Forebay, Los Angeles County, California......................................................................113

Figure 43. Graph showing trihalomethane to total organic halide ratios (THM/TOX) and total organic 

halide to dissolved organic carbon ratios (TOX/DOC) for selected samples collected in 

April 1994 at the research basin, Montebello Forebay, Los Angeles County, California.................115

Figure 44. Graph showing attenuation of anionic surfactant concentrations (LAS and MBAS) with 

depth below research basin during infiltration of reclaimed water, April 1994, Montebello 

Forebay, Los Angeles County, California .........................................................................................119
Tables xi

TABLES

Table 1. Descriptive information and cross reference to various alphanumeric identifiers used to 

designate sites at and near the research basin, Montebello Forebay, Los Angeles 

County, California ............................................................................................................................. 11

Table 2. Lithologic log for selected core segments from beneath the research basin, Montebello Forebay, 

Los Angeles County, California ........................................................................................................ 16

Table 3. Distribution of selected bacteria in cores beneath the research basin, Montebello Forebay, 

Los Angeles County, California ........................................................................................................ 23

Table 4. Distribution of total coliform and fecal coliform bacteria during August 1993 recharge 

experiment at research basin, Montebello Forebay, Los Angeles County, California ...................... 24

Table 5. Distribution of total coliform and fecal coliform bacteria in water below the research basin, 

Montebello Forebay, Los Angeles County, California, during April/June 1994 recharge 

experiment ......................................................................................................................................... 25

Table 6. Distribution of ammonia-oxidizing and nitrite-oxidizing bacteria in water below research 

basin, Montebello Forebay, Los Angeles County, California, during April/June 1994

recharge experiment........................................................................................................................... 26

Table 7A. Distribution of nitrate-reducing and denitrifying bacteria in water below research basin, 

Montebello Forebay, Los Angeles County, California, during August 1993 recharge 

experiment ......................................................................................................................................... 26

Table 7B. Distribution of nitrate-reducing and denitrifying bacteria in water below research station, 

Montebello Forebay, Los Angeles County, California, during April/June 1994 recharge 

experiment ......................................................................................................................................... 26

Table 8. Inorganic, isotopic, and field constituents analyzed for this study, Montebello Forebay, 

Los Angeles County, California ........................................................................................................ 29

Table 9. Nitrogen-isotope data for nitrate in water below research basin, Montebello Forebay, 

Los Angeles County, California, during April–June 1994 recharge experiment .............................. 50

Table 10. Amounts of colloid isolated from the research basin, Montebello Forebay, Los Angeles 

County, California, during recharge experiments.............................................................................. 63

Table 11. Elemental analyses, on moisture-free basis, of colloids from the research basin, 

Montebello Forebay, Los Angeles County, California...................................................................... 63

Table 12. Elemental analyses of colloids, on moisture- and ash-free basis, from the research basin, 

Montebello Forebay, Los Angeles County, California...................................................................... 63

Table 13. Selected elemental mass ratios in colloids from the research basin, Montebello Forebay, 

Los Angeles County, California ........................................................................................................ 63

Table 14. Dissolved organic carbon (DOC) fractionation data for samples collected August 23, 1993, 

at the research basin, Montebello Forebay, Los Angeles County, California ................................... 80

Table 15. Selected organic and inorganic carbon data and analytical precision information for

samples collected during the April and September 1994 recharge experiments 

at the research basin, Montebello Forebay, Los Angeles County, California ................................... 83

Table 16. Dissolved (DOC) and total (TOC) organic carbon concentrations before (April 4), during, 

and after (June 1) the 17-day recharge experiment in April 1994 at the research basin, 

Montebello Forebay, Los Angeles County, California...................................................................... 84

Table 17. Dissolved organic carbon (DOC) molecular-weight distribution for samples collected at the

research basin, Montebello Forebay, Los Angeles County, California, in April and 

September 1994 ................................................................................................................................. 85

Table 18. Dissolved organic carbon (DOC) fractionation data for samples collected at the research 

basin, Montebello Forebay, Los Angeles County, California, April 1994........................................ 87
xii Tables

Table 19. Dissolved organic carbon (DOC) fractionation data for samples collected at the research 

basin, Montebello Forebay, Los Angeles County, California, September 1994 ............................... 88

Table 20. Preparative dissolved organic carbon (DOC) fractionating data for reclaimed-water 

effluent (PR13) collected at the research basin, Montebello Forebay, Los Angeles 

County, California, April 5, 1994 ...................................................................................................... 91

Table 21. Concentrations of trihalomethanes (THMs), total organic halides (TOX), and dissolved 

organic carbon (DOC), and ratios of THM/TOX and TOX/DOC, in samples collected 

at the research station, Montebello Forebay, Los Angeles County, California, 

April 7, 1994 ......................................................................................................................................111

Table 22. Concentrations of trihalomethanes (THMs), total organic halogens (TOX), and dissolved 

organic carbon (DOC), and ratios of THM/TOX and TOX/DOC, in samples collected 

at the research basin, Montebello Forebay, Los Angeles County, California, September 1994 .......111

Table 23. Concentrations of methylene blue active substances (MBAS), linear alkylbenzene 

sulfonate (LAS), and caffeine for samples collected at the research basin,

Montebello Forebay, Los Angeles County, California, April 1994 ..................................................120

Table 24. Concentrations of methylene blue active substances (MBAS), linear alkylbenzene 

sulfonate (LAS), and caffeine concentrations for samples collected at the research 

basin, Montebello Forebay, Los Angeles County, California, September 1994 ...............................120

Table 25. Concentrations of volatile organic compounds (VOCs) identified by purge and trap gas 

chromatography-mass spectrometry (GC/MS) in recycled water from the research 

basin (PR12), Montebello Forebay, Los Angeles County, September 1994.....................................121

Table 26. Volatile organic compounds (VOCs) not detected by purge and trap gas chromatographymass spectrometry (GC/MS) in recycled water from the research basin (PR12), Montebello 

Forebay, Los Angeles County, California, September 1994 .............................................................122

Appendix 1. Periodic water-level measurements made near the research basin, Montebello Forebay, 

Los Angeles County, California, between January 1993 and December 1995 .................................130

Appendix 2A–E. Water-quality data for samples collected near the research basin, Montebello Forebay, 

Los Angeles County, California, during August 1993 ......................................................................133

Appendix 3A–F. Water-quality data for samples collected near the research basin, Montebello Forebay, 

Los Angeles County, California, during April and June 1994 ..........................................................195

Appendix 4A–E. Water-quality data for samples collected near the research basin, Montebello Forebay, 

Los Angeles County, California, during September 1994.................................................................225

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples 

collected near the research basin, Montebello Forebay, Los Angeles County, California, during 

August 1993.......................................................................................................................................237

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples 

collected near the research basin, Montebello Forebay, Los Angeles County, California, 

during April and June 1994 ...............................................................................................................246

Appendix 7. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples 

collected near the research basin, Montebello Forebay, Los Angeles County, California, 

during September 1994......................................................................................................................251

Appendix 8A–F. Water-quality data from selected production and monitoring wells, collected near the 

research basin, Montebello Forebay, Los Angeles County, California .............................................253

Appendix 9. Selected field measurements on samples collected for organic characterization near the 

research basin, Montebello Forebay, Los Angeles County, California .............................................259
Conversion Factors, Vertical Datum, and Abbreviations xiii

CONVERSION FACTORS, VERTICAL DATUM, AND ABBREVIATIONS

CONVERSION FACTORS 

Temperature in degrees Celsius (oC) may be converted to degrees Fahrenheit (oF) as follows:

oF=1.8 oC+32.

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

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

micrograms per liter (μg/L). 

VERTICAL DATUM

Sea level: In this report, “sea level” refers to the National Geodetic Vertical Datum of 1929 (NGVD 

of 1929)—a geodetic datum derived from a general adjustment of the first-order level nets of both the 

United States and Canada, formerly called Sea Level Datum of 1929. 

ABBREVIATIONS

ABS alkylbenzene sulfonate

AMU atomic mass unit

APEC alkylphenol polyethyoxy carboxylate

APEO alkylphenol polyethoxylate

Ba barium

BGLB brilliant green lactose broth

C carbon

13C carbon-13

13C-NMR carbon-13 nuclear magnetic resonance [spectrometry]

cfu colony forming units

Cl chloride

Multiply By To obtain

Length

inch (in.) 25.4 millimeter

feet (ft) 0.3048 meters

miles mi) 1.609 kilometers

Area

acre 0.4047 hectare

square inch (in2) 6.452 square centimeter

square foot (ft2) 0.09290 square meter

Volume

cubic inch (in3) 16.39 cubic centimeter

acre-foot (acre-ft) 1,233 cubic meter 

Flow rate

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year

foot per day (ft/d) 0.3048 meter per day

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

Mass

pound, avoirdupois (lb) 0.4536 kilogram 

Pressure

pound per square inch (lb/in2) 6.895 kilopascal 
xiv Conversion Factors , Vertical Datum, and Abbreviations

cm centimeter

cm/s centimeter per second

cm2 square centimeter

cm3 cubic centimeter

CO2 carbon dioxide

CP/MAS cross polarization/magic angle spinning [NMR spectrometry]

da dalton [atomic mass unit]

δD delta deuterium

δ15Ν delta nitrogen−15

δ18O delta oxygen-18

DATS dialkyltetraline sulfonate and dialkylindane sulfonates

DO dissolved oxygen

DOC dissolved-organic carbon

DOCf dissolved-organic carbon fractionation

DOCmw dissolved-organic carbon molecular-weight

DOM dissolved organic matter

Eh electrochemical potential

EM electromagnetic

FTIR Fourier transform infrared spectrometry

GC-ECD gas chromatography with electron-capture detection

GC/MS gas chromatography-mass spectrometry

g gram

g/cm3 gram per cubic centimeter

> greater than

Hz hertz [unit of frequency equal to one cycle per second]

H hydrogen

HCl hydrochloric acid

HPI hydrophilic

HPIa hydrophilic acid

HPIb hydrophilic base

HPIn hydrophilic neutral

HPO hydrophobic

HPOa hydrophobic acid

HPOb hydrophobic base

HPOn hydrophobic neutral

ID identification

IR infrared [spectrometry]

δ isotope mass ratio

ε isotope-separation factor

KBr potassium bromide

kHz kilohertz

KHP potassium hydrogen phthalate

< less than

LAS linear alkylbenzene sulfonate

L liter

Li lithium

M meter

[M+] molecular ion

MBAS methylene blue active substances

MCL maximum contaminant level

MLS multilevel sampler

MPN most probable number

meq/L milliequivalent per liter

meq/100 g millequivalent per 100 grams soil
Conversion Factors, Vertical Datum, and Abbreviations xv

mg milligram

mg C/L milligram carbon per liter

mHz megahertz

min minute

mL milliliter

mm millimeter

ms millisecond

m/z mass-to-charge ratio for molecular ion in GC/MS analysis

μeq/L microequivalent per liter

μL microliter

μm micrometer

μs microsecond

nm nanometer

N nitrogen

NaOH sodium hydroxide

15N nitrogen-15

N2 nitrogen gas

NH4 ammonium

NMR nuclear magnetic resonance 

NO2 nitrite

NO3 nitrate

NOE nuclear Overhauser enhancement

O oxygen

PO4 orthophosphate o/oo per mil (parts per thousand)

ppm part per million

31P phosphorus-31

PO4-P phosphate as phosphorus

POC particulate organic carbon

PVC polyvinyl chloride

s second

SC specific conductance

SEMS scanning electron microscopy

SIM selected-ion monitoring

SPC sulfophenyl carboxylate

SPE solid-phase extraction

Sr strontium

SRFA Suwannee River fulvic acid

TBA tetrabutylammonium hydrogen sulfate

THM trihalomethane

TIC total inorganic carbon

TNTC too numerous to count

TOC total organic carbon

torr unit of pressure equal to 1/760th of an atmosphere

TOX total organic halides

UV/VIS ultraviolet/visible [spectrometry]

VOC volatile organic compound
xvi Conversion Factors , Vertical Datum, and Abbreviations

Organizations

AWWA American Water Works Association

MWD Metropolitan Water District of Southern California

NWIS National Water Information System

NWQL National Water Quality Laboratory (USGS)

U.S. EPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

WRD Water Replenishment District of Southern California
Well-Numbering System xvii

WELL-NUMBERING SYSTEM

Wells are identified and numbered according to their location in the rectangular system for the subdivision of 

public lands. Identification consists of the township number, north or south; the range number, east or west; and the 

section number. Each section is divided into sixteen 40-acre tracts lettered consecutively (except I and O), 

beginning with "A" in the northeast corner of the section and progressing in a sinusoidal manner to "R" in the 

southeast corner. Within the 40-acre tract, wells are sequentially numbered in the order they are inventoried. The 

final letter refers to the base line and meridian. In California, there are three base lines and meridians; Humboldt 

(H), Mount Diablo (M), and San Bernardino (S). All wells in the study area are referenced to the San Bernardino 

base line and meridian (S) Well numbers consist of 15 characters and follow the format 002S011W018L001S. In 

this report, well numbers are abbreviated and written 2S/11W-18L1. Wells in the same township and range are 

referred to only by their section designation, -18L1. The following diagram shows how the number for well 

2S/11W-18L1 is derived.

2S/11W-18L1

D C B A

E F G H

M L K J

N P Q R

6 5 4 3 2 1

7 8 9 10 11 12

18 17 16 15 14 13

19 20 21 22 23 24

30 29 28 26 25

31 32 33 34 35 36

27

R11W R10W

T3S

T2S

T1S

R12W

RANGE

TOWNSHIP

R14W R13W

T4S

T5S

Approximately

6 miles

Approximately

1 mile

Approximately

1/4 mile

R11W

Well-numbering diagram (Note: maps in this report use abbreviated well numbers such as "18L1")

SECTION 18

T2S
xviii 
Abstract 1

Water-Quality Changes and Organic-Carbon 

Characterization During Recharge with Recycled Water 

at a Research Basin in Montebello Forebay, Los Angeles 

County, California, 1991–1996

Edited by Roy A. Schroeder

Contributing Authors: Robert Anders, Larry B. Barber, Jerry A. Leenheer, Ted I. Noyes, 

Ronald R. Rathbun, Terry F. Rees, Colleen A. Rostad, Roy A. Schroeder, Kevin A. Thorn and

Steven J. Younger

ABSTRACT

During the early 1990s, the U.S. Geological 

Survey (USGS) investigated water-quality changes 

that occur in treated municipal wastewater 

(recycled water) at a small research basin 

constructed in the Montebello Forebay of the 

Central Ground-Water Basin in south-central Los 

Angeles County. The instrumented research basin 

is located on a 1/2-acre site at the upgradient end 

of the San Gabriel River Coastal Spreading 

Grounds where recharge has been augmented 

using recycled water since 1961. The facility was 

used to measure attenuation in selected 

constituents as recycled water delivered to the 

basin percolates downward and moves laterally 

beneath the basin. Attenuation in aqueous 

concentration was found to range from 

20 to 60 percent for total dissolved nitrogen and 

was about one-third for dissolved organic carbon 

(DOC). Isotopic data confirmed permanent loss of 

nitrogen by denitrification. Detailed investigations 

showed that there were no large differences in the 

loss of various components of the DOC at the 

structural or compound level, although surfactants 

and their metabolites were abundant and did 

persist in the subsurface. The DOC of wastewater 

origin was found to have a lower trihalomethane 

(THM) formation potential upon chlorination than 

does organic matter of natural origin from most 

surface-water sources.

The organization of this report into 

12 topical chapters, and the report’s relation to 

additional USGS publications from this study, is 

noted in a preface.
2 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

PART I

CHAPTER 1: INTRODUCTION

By Roy A. Schroeder and Robert Anders

Owing to increases in the demand for water in 

the western United States, water-resources managers 

recognize the need to develop methods to optimize 

available supplies. One method of providing additional 

water resources that is receiving widespread attention, 

especially in southern California and Arizona, is 

wastewater reclamation and reuse (the terms “recycled” 

and “reclaimed” water are used interchangeably 

throughout this report as they are in the industry). 

Reuse can be characterized as potable or nonpotable, 

direct or indirect. Direct nonpotable-water reuse for 

urban irrigation, cooling, industrial processing, 

recreation, and agriculture is already widely practiced, 

leaving resources of high-quality fresh water for 

potable use (California State Water Resources Control 

Board, 1987). The only potable-water reuse currently 

practiced in the United States is indirect, wherein 

wastewaters are discharged to the environment and 

withdrawn downgradient or downstream from either 

underground or surface sources (Sloss and others, 

1996, and references therein). 

In southern California, 240,000 acre-feet per 

year (acre-ft/yr) of the locally supplied water comes 

from reclaimed water, and most (183,000 acre-ft/yr) of 

this is used to recharge local ground-water basins 

(Anders and Schroeder, 1997, from Metropolitan Water 

District of Southern California [MWD], unpub. data). 

Since 1991 approximately 50,000 acre-ft/yr of 

reclaimed water has been used by the Water 

Replenishment District of Southern California (WRD) 

to artificially recharge the Montebello Forebay area of 

the Central Ground Water Basin (Central Basin) in 

south-central Los Angeles County (fig. 1). It is 

estimated that almost 1 million residents in the 

Montebello Forebay area, where artificial recharge 

using reclaimed water has been practiced since 1961, 

receive some reclaimed water in their household 

supply. Artificial recharge in the Montebello Forebay is 

accomplished by diverting water, including reclaimed 

water, into large holding ponds at the Rio Hondo 

(570 acres) and the San Gabriel River Coastal 

Spreading Grounds (128 acres), located in Montebello 

and Pico Rivera, respectively, and into the unlined 

reach of the San Gabriel River (156 acres) adjacent to 

the San Gabriel River Coastal Spreading Grounds

(fig. 2). These holding ponds, or spreading basins, and 

the unlined reach of the San Gabriel River, allow the 

reclaimed water to infiltrate into the ground and 

replenish the ground-water aquifers in the area. As 

improvements are made to increase the treatment 

capacity of the domestic wastewater at the Whittier 

Narrows, Pomona, and San Jose Creek Water 

Reclamation Plants, located north of the Montebello 

Forebay, the supply of reclaimed water potentially 

available to the spreading grounds will increase.

However, there are restrictions on the use of 

reclaimed water for spreading purposes. Artificial 

recharge using reclaimed water is regulated under Title 

22 of the California Administrative Code, and the 

California Regional Water Quality Control Board, 

through input from the State Department of Health 

Services, sets permissible limits on the amount of 

reclaimed water that can be used for replenishment 

purposes. Beginning in 1991, the quantity of reclaimed 

water authorized for surface spreading in the 

Montebello Forebay was increased to no more than 

50 percent of recharged water annually and to 35 

percent during any 3-year period. The regulation states 

that, “reclaimed water used for groundwater recharge 

of domestic water supply aquifers by surface spreading 

shall be at all times of a quality that fully protects 

public health” (Barclay's California Code of 

Regulations, 1978; and California Department of 

Health Services, 1978). This regulation does not 

account for the effects of infiltration and mixing on the 

quality of the reclaimed water.
Chapter 1: Introduction 3

Gabriel

Gabriel

River

San

Balboa

Cr

San

Rio

Hondo

River

Los

Los

R

River

Angeles

Angeles

NewportInglewood

Uplift

Long Beach

Signal

Hill

Repetto Hills Merced Hills

Elysian

Hills

Puente Hills

Dominguez

Hills

Palos Verdes Hills

San

Valley Gabriel

San Fernando Valley

Santa Monica Mountains

Los Angeles

Huntington

Beach

Seal Beach

Orange County

Los Angeles County

0 10 MILES Geology redrawn from

Reichard and others, 2003

Base map from U.S. Geological

Survey digital maps 1:24,000

0 10 KILOMETERS

50'

20' 10'

Pacific Ocean

Santa Monica Bay

San Pedro Bay

Central Basin

West Coast Basin

Hollywood Basin

Santa Monica

Basin

Montebello

Pressure

Area

Forebay

Los Angeles

Forebay

Whittier

Narrows

Los

Angeles

Narrows

Research

Basin

Pico Rivera

Whittier Narrows

Flood Control Basin

118 30' 118 00'

34 10'

34 00'

33 40'

Unconsolidated deposits

Consolidated rocks

Spreading grounds

EXPLANATION

Los Angeles

CALIFORNIA

San

Francisco

San Diego

Los Angeles

County

Study

area

Figure 1. Location of the research basin study area in Montebello Forebay, Los Angeles County, California.
4 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

34 04'

34 00'

33 58'

118 08' 118 00'

23 24 19 21 20 23

28 27 26 29 28 27

33 34 35 36 31 32 34 35

4 3 4 2

9 7

8 11 10 9 10

16 15 14 18 16 15

22 21 23 24 19 20 21 22 23

27 26 28

25

30 29 28 27 26

22

26

3

11

14

21 22

25 30

33

2 1 6 5

12

17

13

T1S

T2S

R12W R11W

Gabriel

San

Hondo

Rio

River

60

60

Norwalk

Rosemead Blvd

Whittier Blvd

Washington Blvd

03'

07' 06' 05' 03' 02' 01'

02'

01'

59'

Line of section

(fig. 5)

0 2 MILES

0 2 KILOMETERS

Consolidated rocks

Unconsolidated deposits

EXPLANATION

Background well

Monitoring well

Research basin

Spreading grounds

Whittier Narrows

Flood Control Basin

Narrows

Whittier

Montebello

Forebay

Rio Hondo

Spreading

Grounds

San Gabriel

River Spreading

Grounds

Puente Hills

Repetto Hills

605

5

10

Merced Hills

19E1

19C1

18P1

24R1

24R1

25Q1

7J1

7J1

Figure 2. Location of the U.S. Geological Survey/Water Replenishment District of Southern California research basin in Pico Rivera, Los Angeles County, 

California.
Chapter 1: Introduction 5

Although the use of reclaimed water is 

adequately monitored in general, and a 1987–91 

epidemiologic study failed to detect any adverse effects 

on health (Sloss and others, 1996), there is little 

quantitative information on the changes in quality of 

the reclaimed water as it enters the spreading grounds, 

percolates to the water table, and mixes with ground 

water beneath the spreading grounds, or as the 

reclaimed water moves from the spreading grounds to 

the point of withdrawal. If more information were 

available, the regulation could be revised to allow for 

possible quality improvements of the reclaimed water 

during artificial recharge and still provide adequate 

protection to public health. The ongoing study 

described herein was undertaken to better understand 

the processes that contribute to the changes in quality 

of the reclaimed water during artificial recharge and to 

provide information that can be used to revise and 

update the regulations on indirect potable reuse in 

California. 

To facilitate this study, the United States 

Geological Survey (USGS), in cooperation with the 

Water Replenishment District of Southern California 

(WRD), constructed a research basin on an 

approximately 1/2-acre site at the north (upgradient) 

end of the San Gabriel River Coastal Spreading 

Grounds (fig. 1).

Purpose and Scope

The purpose of this report is to describe the 

water-quality changes that resulted during three 

recharge experiments using reclaimed water at the 

research basin in 1993–1994. The results are presented 

in 12 chapters, each of which deals with a different 

aspect of the study, and in 9 appendixes, which consist 

of tables of data. The first part of the report (chapters 

1–5) contains a description of the study area and its 

instrumentation, microbiology, and inorganic water 

quality. The second part (chapters 6–12) describes the 

characterization of natural and contaminant organic 

matter and the changes that take place during recharge. 

This characterization required extensive development 

of new analytical protocols for separation and isolation 

of organic matter. These methods are described briefly 

herein; detailed descriptions of methods are given in 

cited references.

Acknowledgments

This study was funded by a cooperative 

agreement between the Water Replenishment District 

of Southern California and the U.S. Geological Survey. 

The authors also acknowledge the support of the 

County Sanitation Districts of Southern California, 

which operate the treatment plants that produce the 

reclaimed water, and the Los Angeles County 

Department of Public Works, which operates the 

diversion facilities and spreading grounds in 

Montebello Forebay where the reclaimed water and 

(or) stormwater and imported water are recharged. The 

authors thank Dr. Rodger Baird, Anthony Buono, Julia 

Huff, Rick Iwatsubo, Dr. Eric Reichard, Dr. Ralph 

Seiler, Kay Witter, and Jerrald Woodcox for providing 

helpful reviews and comments and several staff 

members for graphics and report preparation.
6 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 2: RESEARCH BASIN 

CONSTRUCTION AND INSTRUMENTATION

By Terry F. Rees and Robert Anders

The USGS/WRD research basin was constructed 

at the north end of the San Gabriel River Coastal 

Spreading Grounds located between Whittier 

Boulevard and Washington Boulevard in Pico Rivera, 

Los Angeles County, California (figs. 1, 2). Overlying 

silt was excavated from the site to expose a well-sorted 

sand and gravel unit about 10 ft below local land 

surface. The excavated material was used to construct a 

berm around the research basin to isolate it from the 

rest of the spreading grounds and a settling (desilting) 

basin (fig. 3) at the head of the spreading grounds. The 

berm was constructed with a 3:1 (horizontal-tovertical) slope and was topped by a 10-foot-wide 

access road. This construction left an exposed 

percolation area of about one-half acre and provided an 

operating water depth of about 8 ft to the catwalk (fig. 

4).

Reclaimed water is delivered from the waterreclamation facilities, where it has undergone tertiary 

treatment, to the spreading grounds through an 8-footdiameter culvert. The tertiary treatment consists of 

dual-media (anthracite coal and sand and gravel) 

filtration followed by chlorination and dechlorination. 

A small percentage of the flow can be diverted on 

demand to the research basin through a 6-inch pipeline 

using a PACO PC 51 non-clog 100 gal/min submersible 

pump installed in the culvert (PR13) (fig. 3). A 

constant head is maintained in the research basin by 

controlling the pump using a SOR float-operated, 

water-level control switch installed in a stilling well 

(fig. 3) located in the research basin (PR12).

Research-basin instrumentation was installed in 

bore holes drilled using a 4 1/2-inch hollow-stem 

auger. A description of all instruments installed follows 

and their locations and site designations are shown in 

figures 2–4. A schematic (fig. 4) shows distance of 

instruments from the center of the pond and depth 

below the research basin. Some of the instruments have 

received little or no use to date but are intended for 

possible future use.

 To facilitate collection of unsaturated-zone poremoisture samples, suction lysimeters (sites designated 

PR1, 3 and 5 in figs. 3 and 4—PR4 not shown in 

figures) were installed at depths of about 5, 10, 15, 25, 

and 50 ft below the research-basin floor at each site. 

The lysimeters were installed by drilling to the deepest 

depth and then suspending the deepest lysimeter in the 

hollow-stem auger flights. Sufficient silica flour was 

poured into the flights to encase the lysimeter's porouscup from at least 1 ft below the bottom to at least 1 ft 

above the top of the cup. Bentonite chips were placed 

into the borehole annulus above and below the silica 

flour as the auger flights were withdrawn, thereby 

providing a hydraulic seal above and below each 

lysimeter. A bentonite seal was installed from the top 

of the silica flour for the 5-foot (shallowest) lysimeter 

to land surface.

Three different types of suction lysimeters were 

installed: ceramic, stainless steel, and Teflon. The twostage ceramic-cup lysimeters (PR1) are constructed by 

Soil Moisture Equipment Corporation, Santa Barbara, 

California, from polyvinyl chloride (PVC) pipe to 

which a porous ceramic cup is attached. The two-stage 

construction and the installation of a check valve 

between the stages allow these lysimeters to be used 

successfully to depths of at least 250 ft (Schroeder and 

others, 1993; Umari and others, 1995). Collected 

samples are delivered to the surface through smalldiameter access tubes. Ceramic-cup lysimeters can be 

used to collect pore-moisture samples for major 

inorganic constituents (Peters and Healy, 1988), but 

they may not provide reliable samples for organic 

constituents, and the small pore opening (nominal pore 

size of 1.4 μm) makes them unsuitable for collection of 

microorganisms (Dazzo and Rothwell, 1974). Stainless 

steel lysimeters (PR3) obtained from Soil 

Measurement Systems, Tucson, Arizona, were installed 

to permit collection of samples for analysis of organic 

constituents and microorganisms. These lysimeters are 

constructed entirely from welded stainless steel and 

utilize a porous fretted steel material for the porous 

cup. Because the porous steel fret has a much larger 

mean pore diameter (50 μm) than do the ceramic cups, 

they cannot produce as high a suction, and they do not 

work as well in drier soils. All-Teflon lysimeters (PR5) 

obtained from Timco Manufacturing, Inc., also were 

installed. These lysimeters have the potential to be used 

for collecting samples for both inorganic and organic 

constituents, but they have the disadvantage of being 

strongly hydrophobic, requiring extreme suction to 

collect water from the soil pores.
Chapter 2: Research Basin Construction and Instrumentation 7

EXPLANATION

Bottom of basin

Research basin and catwalk

Sloping edge of

basin

Local site

identifier

(See table 1)

0 100 FEET

0 30 METERS

San

Gabriel

River

WP8

WP3

WP4

WP5

WP7

WP6

Transmission

tower

Road

North

Line of section

(fig. 4)

Transmission

lines

North

PR 12

(Research basin)

Berm

Berm

PR10 PR11

PR11

PR6 WP2 PR9 PR8

WP1

MLS

4–20

40'

Stilling

well

Desilting basin

Catwalk

PR13

(effluent)

PR 12

(Research basin)

0 40 FEET

0 10 METERS

20 Road

Road

Access

Vehicle

PR3 PR5 PR7 PR1

Figure 3. Location of instrumentation sites at the U.S. Geological Survey/Water Replenishment District of Southern California research basin, 

Montebello Forebay, Los Angeles County, California. (See table 1 for description of instrumentation.)
8 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

DISTANCE , IN FEET

–20 40 60 0 20 80 100 120 140 160 180

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

–10

0

10

20

30

40

50

60

WP3

WP4

WP5

WP1

WP2

WP8

WP7

WP6

Sampling ports

Catwalk

Berm Berm

MLS4–20

PR9

PR8

PR1

PR3

PR5

PR7

PR6

Settling basin

(Desilting)

PR12

(Research basin)

Slope

PR10

PR11

Figure 4. Sampling instrumentation at the U.S. Geological Survey/Water Replenishment District of Southern California research basin, Montebello 

Forebay, Los Angeles County, California. (WP9–11, located about 850 feet south of the research basin, are not shown; see table 1 for description and figure 

3 for location of instrumentation.)
Chapter 2: Research Basin Construction and Instrumentation 9

The research basin is instrumented for two 

independent methods of measuring soil-moisture 

contents. The first method uses neutron thermalization 

by hydrogen atoms in water (Troxler Electronic 

Laboratories, Inc., 1983). A sealed 2-inch-diameter 

galvanized steel neutron-log access tube was installed 

by augering a bore hole (PR6) to a depth of 50 ft below 

the research-basin floor and carefully segregating the 

cuttings delivered to the surface. The tube was lowered 

into the hollow-stem auger flights, and auger rotation 

then was reversed. The collected cuttings were 

reintroduced into the hole as the flights unscrewed 

themselves from the hole. A bentonite surface seal was 

installed to minimize vertical leakage down the 

borehole. To facilitate collection of soil gas samples, 

one-fourth-inch copper gas-sampling tubes were 

attached to this access tube prior to installation at 

depths of 5, 10, 15, 25, and 40 ft below the floor of the 

research basin.

The second method for measuring soil-moisture 

content is based on response of radio waves to changes 

in dielectric constant of the soil (Troxler Electronic 

Laboratories, Inc., 1992). Wet soil has a higher 

dielectric constant than does dry soil, resulting in a 

frequency shift for the resonant radio waves. In this 

technique a logging tool is used that has a radiofrequency generator and a detector antenna. The 

generator propagates a wave through the access tube 

into the soil, and the antenna measures the reflected 

signal. The access tube for this method (PR7) is a 

2-inch-diameter PVC pipe, and the method of 

installation is the same as described for the neutron-log 

access tube.

The instrumentation for the saturated zone of the 

research basin includes two 2-inch-diameter PVC 

monitoring wells and two 2-inch-diameter galvanizedsteel well points installed in the center of the research 

basin, two 2-inch-diameter PVC monitoring wells 

(piezometers) installed in the surrounding berm, and 

nine 2-inch-diameter galvanized-steel well points 

installed at various depths downgradient. The four 

monitoring wells have 5-foot screens and the well 

points have 2.5-foot screens. Monitoring wells within 

the research basin were installed at 49 ft (PR8, below 

the clay lens) and 25 ft (PR9, above the clay lens) 

below the floor of the research basin. The monitoring 

wells at the top of the 10-foot berm were installed at

60 ft (PR10, below the clay lens) and 36 ft (PR11, 

above the clay lens) below land surface. The 

monitoring wells located above the clay lens were 

installed by drilling just to the clay lens, placing 

bentonite seals at the bottom, and then suspending the 

screens and casings inside the hollow-stem auger 

flights. Monterey Number 2 (coarse) sand then was 

tremied around and above the screens to act as a 

formation filter. The bore holes were grouted from the 

top of the sand filters to the top of the bore holes using 

a bentonite slurry. The monitoring wells located below 

the clay lens were installed using the same techniques, 

except the bore holes were drilled to 55 ft below the 

floor of the research basin, and 5-foot bentonite seals 

were installed below the screens. The tops of the 

screens did not penetrate the clay lens. The grout seals 

extended from the top of the sand filters, through the 

clay lens, to the surface of the boreholes.

The 2-inch-diameter well points consisted of a 

conical drive shoe at the bottom, a well screen of 2.5 ft, 

and a galvanized-steel pipe that extended from the 

depth of installation to a sufficient height to provide 

access during recharge experiments. The well points 

were hammer-driven into undisturbed soil using a 

75-pound jackhammer; because they were driven into 

undisturbed soil, no sand filter or bentonite seals were 

used. Eleven well points were installed: two near the 

center of the research basin at depths of about 5 and 

10 ft (WP1 and WP2, respectively); three a short 

distance south from the research basin in the 

downgradient direction of regional ground-water flow 

at depths of about 5, 10, and 20 ft below the desilting 

basin (WP8, WP7, and WP6, respectively); three 150 ft 

south of the research basin at depths of about 5, 10, and 

20 ft (WP3, WP4, and WP5, respectively); and three 

more 850 ft south of the research basin. These farthest 

downgradient well points were installed at depths of 

about 5, 10, and 15 ft below the spreading ground 

(WP9, WP10, and WP11, respectively). The 

4 monitoring wells and 11 well points were 

hydraulically developed using air-surging.
10 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

The final research basin instrumentation was an 

all-Teflon multiple-level sampler (MLS3–20) designed 

to allow collection of samples at 1-foot intervals from 

just below the water table to a depth of 20 ft below the 

floor of the research basin. This sampler received by far 

the greatest use during the recharge experiments. It 

consists of 18 one-fourth-inch Teflon tubes extending 

from the floor of the basin, down the inside of a 2-inch 

PVC casing, and out holes drilled through the PVC at 

selected depths. The down-hole end of the tubes is 

screened with a fine Teflon fabric. The vertical spacing 

between the tubes is 1 ft starting at a depth of 4 ft (port 

at 3-foot depth does not operate) below the researchbasin floor and extending to a depth of 20 ft. The 

design of the sampler is similar to that of the PVC 

multiple-level samplers used at the U. S. Geological 

Survey Otis Air Force Base research site and has been 

described in detail by LeBlanc and others (1991).

Two-foot-square concrete footings were installed 

on top of each bore hole through which the sample 

tubing or casing was passed. Galvanized pipe was set in 

these footings to allow routing of the tubes and casings 

to a catwalk above the basin. The catwalk extends from 

the southern berm to the center of the basin where 

instrumentation is installed (fig. 3). The catwalk 

provides access to the instrumentation during recharge 

experiments.

In table 1, descriptive information on the 

instrumentation is cross referenced to station names, 

USGS site identification numbers (site ID), and local 

identifiers (local ID). Most chemical and water-level 

data are stored and can be retrieved from NWIS (the 

USGS computerized database) by station name or by 

site ID. Station name is the “State well number” for 

piezometers and lysimeters, and site ID is the 13-digit 

latitude and longitude (in degrees, minutes, and 

seconds) followed by 2 digits that distinguish sites (for 

example, different depths of a multilevel well) having 

the same latitude and longitude. Alphanumeric 

acronyms, composed of parts of these various 

identifiers, are used (because of their brevity and 

simple descriptive nature) throughout this report and in 

the schematic (fig. 4) to designate samplers and sites.
Chapter 2: Research Basin Construction and Instrumentation 11

Table 1. Descriptive information and cross reference to various alphanumeric identifiers used to designate sites at and near the research basin, Montebello 

Forebay, Los Angeles County, California—Continued

Station name USGS site

identification No. Local identifier Description

2S/11W-18L10SLYS 335943118042201 PR1-CR-RED at 50 ft Ceramic-cup lysimeters at 

designated depths beneath 

the research basin

2S/11W-18L11SLYS 335943118042202 PR1-CR-ORG at 25 ft

2S/11W-18L12SLYS 335943118042203 PR1-CR-YEL at 13.5 ft

2S/11W-18L13SLYS 335943118042204 PR1-CR-BLU at 6 ft

2S/11W-18L14S A INTRVL 335943118042205 PR2 (MLS20) at 20 ft All-teflon multilevel sampler at 

designated depths from 3 to 

20 ft beneath the research 

basin

2S/11W-18L14S B INTRVL 335943118042206 PR2 (MLS19) at 19 ft

2S/11W-18L14S C INTRVL 335943118042207 PR2 (MLS18) at 18 ft

2S/11W-18L14S D INTRVL 335943118042208 PR2 (MLS17) at 17 ft

2S/11W-18L14S E INTRVL 335943118042209 PR2 (MLS16) at 16 ft

2S/11W-18L14S F INTRVL 335943118042210 PR2 (MLS15) at 15 ft

2S/11W-18L14S G INTRVL 335943118042211 PR2 (MLS14) at 14 ft

2S/11W-18L14S H INTRVL 335943118042212 PR2 (MLS13) at 13 ft

2S/11W-18L14S I INTRVL 335943118042213 PR2 (MLS12) at 12 ft

2S/11W-18L14S J INTRVL 335943118042214 PR2 (MLS11) at 11 ft

2S/11W-18L14S K INTRVL 335943118042215 PR2 (MLS10) at 10 ft

2S/11W-18L14S L INTRVL 335943118042216 PR2 (MLS9) at 9 ft

2S/11W-18L14S M INTRVL 335943118042217 PR2 (MLS8) at 8 ft

2S/11W-18L14S N INTRVL 335943118042218 PR2 (MLS7) at 7 ft

2S/11W-18L14S O INTRVL 335943118042219 PR2 (MLS6) at 6 ft

2S/11W-18L14S P INTRVL 335943118042220 PR2 (MLS5) at 5 ft

2S/11W-18L14S Q INTRVL 335943118042221 PR2 (MLS4) at 4 ft

2S/11W-18L14S R INTRVL 335943118042222 PR2 (MLS3) at 3 ft

2S/11W-18L15SLYS 335943118042223 PR3-SS-RED at 49 ft Stainless steel lysimeters at 

designated depths beneath 

the research basin

2S/11W-18L16SLYS 335943118042224 PR3-SS-ORG at 25 ft

2S/11W-18L17SLYS 335943118042225 PR3-SS-YEL at 15 ft

2S/11W-18L18SLYS 335943118042226 PR3-SS-GRE at 10 ft

2S/11W-18L19SLYS 335943118042227 PR3-SS-BLU at 5 ft

2S/11W-18L20SLYS 335943118042228 PR4-CR-YEL at 15 ft Ceramic-cup lysimeters at 

designated depths beneath 

the research basin

2S/11W-18L21SLYS 335943118042229 PR4-CR-GRE at 9 ft

2S/11W-18L22SLYS 335943118042230 PR5-TF-RED at 48 ft Teflon lysimeters at designated 

depths beneath the research 

basin

2S/11W-18L23SLYS 335943118042231 PR5-TF-ORG at 25 ft

2S/11W-18L24SLYS 335943118042232 PR5-TF-YEL at 15 ft

2S/11W-18L25SLYS 335943118042233 PR5-TF-GRE at 10 ft

2S/11W-18L26SLYS 335943118042234 PR5-TF-BLU at 5 ft

Neutron probe access tube 335943118042235 PR6-NEUTRON Soil-moisture instrumentation

Table 1. Descriptive information and cross reference to various alphanumeric identifiers used to designate sites at and near the research basin, Montebello 

Forebay, Los Angeles County, California

[ft, feet; —, site not formally established; PVC, polyvinyl chloride]
12 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

40 ft soil gas tube, Pico Test Site 335943118042236 PR6-GAS at 40 ft Soil-gas instrumentation

25 ft soil gas tube, Pico Test Site 335943118042237 PR6-GAS at 25 ft

15 ft soil gas tube, Pico Test Site 335943118042238 PR6-GAS at 15 ft

10 ft soil gas tube, Pico Test Site 335943118042239 PR6-GAS at 10 ft

5 ft soil gas tube, Pico Test Site 335943118042240 PR6-GAS at 5 ft

Radio frequency attenuation tube 335943118042241 PR7-RFA at 40 ft Soil-moisture instrumentation

2S/11W-18L27S 335943118042242 PR8 at 49 ft PVC monitoring wells at 

designated depths beneath 

the research basin

2S/11W-18L28S 335943118042243 PR9 at 25 ft

2S/11W-18L29S 335943118042244 PR10 at 60 ft

2S/11W-18L30S 335943118042245 PR11 at 36 ft

Research basin pond 335943118042246 PR12

Sewage effluent 335943118042247 PR13

2S/11W-18L31S 335943118042248 WP1 at 7 ft Galvinized-steel well points

2S/11W-18L32S 335943118042249 WP2 at 12 ft

2S/11W-18L33S 335943118042401 WP3 at 7 ft

2S/11W-18L34S 335943118042402 WP4 at 11.6 ft

2S/11W-18L35S 335943118042403 WP5 at 20.6 ft

 — — WP6 at 18.7 ft

 — — WP7 at 12 ft

 — — WP8 at 7 ft

 — — WP9 at 7.2 ft

 — — WP10 at 12 ft

 — — WP11 at 17 ft

2S/11W-18P1S 335935118042901 1620QQ Other PVC monitoring wells

2S/11W-19E1S 335859118045001 1611R

2S/11W-19C1S 335921118043001 1620RR

2S/12W-24R1S 335738118051301 1612T

2S/12W-25Q1S 335835118045801 1613V

2S/11W-7J1S 340045118035501 City of Whittier production well Background well

Table 1. Descriptive information and cross reference to various alphanumeric identifiers used to designate sites at and near the research basin, Montebello 

Forebay, Los Angeles County, California—Continued

Station name USGS site

identification No. Local identifier Description
Chapter 3: Geologic and Hydrologic Setting 13

CHAPTER 3: GEOLOGIC AND HYDROLOGIC 

SETTING

By Robert Anders and Roy A. Schroeder

A brief geohydrologic description of the study 

area is given in this chapter. More extensive 

descriptions can be found in Reichard and others 

(2003). The two main hydrologic features of the 

Central Basin are the Whittier Narrows and the 

Montebello Forebay area (fig. 1). The Whittier 

Narrows is a gap between the Puente Hills and La 

Merced Hills through which the Rio Hondo and San 

Gabriel Rivers exit southward from the San Gabriel 

Valley (Nikkel and others, 1989). The Montebello 

Forebay area, the most important area of recharge in 

the Central Basin, extends southward from the Whittier 

Narrows (California Department of Water Resources, 

Southern District, 1961). The water-bearing aquifers 

(fig. 5), which consist of sedimentary deposits of sand, 

gravel, silt, and clay, range in age from Holocene to 

early Pleistocene and extend to a maximum depth of 

about 1,050 ft below land surface in the Central Basin. 

The Holocene alluvium contains parts of the 

semiperched aquifer, the Bellflower aquiclude, and the 

eastern arm of the Gaspar aquifer. From the Whittier 

Narrows south (about 8 mi) to the Imperial Highway, 

the Bellflower aquiclude is not present and the Gaspar 

aquifer is exposed at land surface. Beneath the Gaspar 

aquifer are several aquifer units that are either merged 

or in direct hydraulic connection with each other, 

including the Gardena and Gage aquifers of the upper 

Pleistocene Lakewood Formation and the Hollydale, 

Jefferson, Lynwood, Silverado, and Sunnyside aquifers 

of the lower Pleistocene San Pedro Formation 

(California Department of Water Resources, Southern 

District, 1961). 

Major structural features of the study area are the 

northeast-trending Rio Hondo, Pico, and Cemetery 

Faults in the Whittier Narrows and Montebello Forebay 

area. The fault trends are virtually parallel to the 

northeast-to-southwest direction of ground-water 

movement in the Montebello Forebay area and do not 

affect the main subsurface inflow of ground water to 

the Central Basin through the Whittier Narrows 

(California Department of Water Resources, Southern 

District, 1961).

Analysis of core material and water levels was 

used to characterize geohydrological conditions on a 

local scale at and near the research basin.

Lithology

 Core material was recovered at approximately 

1-foot intervals to a depth of 35 ft below the floor of the 

research basin [45 ft below land surface at the berm 

(PR10)] by driving a stainless steel, split-spoon core 

barrel through the bottom of the hole drilled by hollowstem augering. A lithology log was compiled from field 

observations. Grain-size distribution of the core 

material was determined at the USGS Sediment 

Laboratory in Salinas, California, using sieves to 

analyze the sand fraction and hydrometers to analyze 

the fine fractions using methods described by Guy 

(1969).
14 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California San Gabriel River Rosemead Blvd Puente Hills Rio Hondo

Montebello Forebay Area

Whittier Narrows

NORTHWEST SOUTHEAST

Base of

freshwater

Base of

freshwater Base of

freshwater

Undifferentiated

(Pliocene)

formations

Undifferentiated

(Miocene)

sediments

Sunnyside

aquifer

Silverado

aquifer

Silverado aquifer

Lynwood aquifer

Sunnyside

aquifer Sunnyside

aquifer

Gaspar aquifer

Gardena aquifer

Jefferson

aquifer

Hollydale aquifer

FEET

400

200

Sea Level

200

400

600

800

1,000

1,200

Lynwood

aquifer

San Pedro Formation

Aquifer

EXPLANATION

14,692 feet

Rio Hondo Fault

Pico Fault

Figure 5. Hydrogeologic section of the Montebello Forebay area, Los Angeles County, California (after California Department of Water Resources, 

Southern District, 1961). Line of section shown in figure 2.
Chapter 3: Geologic and Hydrologic Setting 15

A lithologic log (table 2) compiled from visual 

inspection indicates that soil beneath the research basin 

is predominantly fine-to-coarse, moderately sorted, 

grayish-brown sand. Measured grain-size distributions 

beneath the research basin (PR10) indicate mostly 

medium to coarse sand (fig. 6). Both the descriptive 

lithology and the measured grain-size distribution 

indicate the presence of a clay-rich lens beginning 

about 31 ft below the floor of the research basin (about 

40 ft below land surface). Presence of this clay lens 

also is confirmed by electromagnetic induction (EM) 

and natural gamma radiation logs at PR8 and PR10 

(fig. 7). Cores for analysis of grain size were recovered 

from the berm (PR10), just outside the research basin, 

and results indicate a clay-rich lens that may be as thin 

as 1 ft; the EM log within the basin (PR8) suggests a 

thickness of perhaps a few feet. The lens may thin 

southward, or be of variable thickness, even over short 

distances at the research basin. Below the clay lens is a 

lower sand unit, the depth of which is not known from 

this study because drilling stopped at about 50 ft below 

the floor of the research basin.

Vertical Hydraulic Conductivity

Cores were collected for a distance of several 

feet beneath the research basin to measure vertical 

hydraulic conductivities. The cores were obtained by 

driving a manually operated piston sampler into the 

unconsolidated sediment using an electric jackhammer. 

The core barrels were retrieved, cut to remove any 

unused portion, sealed at both ends to minimize further 

disturbance, and transported to the San Diego State 

University Water Laboratory where they were cut into 

short sections. 

A constant-head permeameter test was chosen to 

measure the hydraulic conductivities of the core 

sections (Fetter, 1988). Cores were first completely 

saturated from the bottom to prevent air bubbles, which 

would have the effect of lowering the hydraulic 

conductivities by decreasing the cross-sectional area of 

soil through which the water can flow. Then water was 

allowed to flow from the top through the core section at 

a steady rate from a chamber with an overflow to 

supply the water at a constant head. Hydraulic 

conductivity (K) is calculated from a variation of 

Darcy's law: 

K = (V L)/(A t h)

where 

The cross-sectional area of each core was 19.635 

cm2 (3.043 in2) and lengths varied from 13.5 to 23.5 

cm (5.3 to 9.3 in.). The three hydraulic heads used for 

the analysis were 60, 70, and 80 cm. Water discharged 

through the apparatus was measured after 60 seconds 

and ranged from less than 1 cm3 (0.06 in3) to almost 

200 cm3 (12 in3).

V is the volume of water discharging in time t,

L is the length of the sample,

A is the cross-sectional area of the sample, and 

h is the hydraulic head.
16 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Table 2. Lithologic log for selected core segments from beneath the research basin, Montebello Forebay, Los Angeles County, California

[Rock-color terms from Goddard and others, 1948; depth, in feet below bottom of research basin]

Depth Description

From To

1 2.4 Silty sand, very fine to very coarse; poorly sorted; angular to sub-rounded; moderate cohesion; very 

dark grayish-brown (10YR 3/2).

2.8 3.9 Sand, very fine to very coarse; no silt or clay; moderately sorted; angular to sub-rounded; gray 

(10YR 6/1).

4.0 4.8 As above with slight increase in silt.

4.8 5.6 Sand, some silt, very fine to fine; well sorted; angular to sub-angular; grayish-brown (2.5YR 5/2).

5.6 7.0 Sand, some silt, very fine to coarse; well sorted; skewed toward fine; angular to sub-angular; 

grayish-brown (2.5Y 5/2).

7.0 8.0 Sand, some gravel granules and pebbles, very fine to very coarse; poorly sorted; angular to 

sub-rounded; grayish-brown (2.5Y 5/2).

8.5 9.7 Sand, abundant granules and small pebbles, fine to very coarse; moderately sorted; skewed toward 

coarse; angular to sub-rounded; light brownish gray (2.5Y 6/2).

10.0 11.5 As above

11.5 12.9 Sand, some gravel granules, fine to very coarse; moderately sorted; skewed toward coarse; angular to 

sub-rounded; grayish brown (2.5Y 5/2).

13.0 14.2 Sand, some gravel granules, trace gravel pebbles, fine to very coarse; moderately sorted; skewed toward 

coarse; angular to sub-rounded; grayish brown (2.5Y 5/2).

30.5 31.4 Sand, very fine to very coarse, moderately sorted; skewed toward coarse; angular to sub-angular; 

light yellowish brown (2.5Y 6/3).

31.4 32.0 Silt, moderately consolidated; moderately to highly fractured; olive yellow (2.5Y 6/6).

32.2 32.8 Sand, very fine to coarse; well sorted; skewed toward fine; angular to sub-angular; light olive brown 

(2.5Y 5/3).

33.0 33.5 Sand, very fine to medium; very well sorted; skewed toward fine; angular to sub-angular; light olive 

brown (2.5Y 5/3).

34.3 34.8 Sand, very fine to coarse; well sorted; skewed toward fine; angular to sub-angular; light olive brown 

(2.5Y 5/3).
Chapter 3: Geologic and Hydrologic Setting 17

PARTICLE SIZE, IN MILLIMETERS

10 1 0.1 0.01 0.001

PERCENT FINER THAN INDICATED PARTICLE SIZE

0

20

40

60

80

100

1.0–2.4

2.8–3.9

4.8–5.6

4.0–4.8

6.2–7.0

5.6–6.2

7.0–8.0

8.5–9.7

10.0–11.5

11.5–12.9

13.0–14.2

31.4–32.0

30.5–31.4

32.2–32.8

33.0–33.5

34.3–34.8

28.0 (fill)

Depth below

floor of

research

basin, in feet

EXPLANATION + +

+

+

+

+ +

+

+

+

+ + + +++

Figure 6. Grain-size distribution for core material collected from selected depths at PR10 beneath the research basin, Montebello Forebay, Los Angeles 

County, California.
18 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

GAMMA RADIATION

COUNTS PER SECOND

0 50 100 150 200 250 300

DEPTH BELOW LAND SURFACE, IN FEET

0

10

20

30

40

50

60

PR8

PR10

ELECTROMAGNETIC INDUCTION

MILLISIEMENS PER METER

0 20 40 60 80 100

PR8

PR10

Figure 7. Electromagnetic induction and natural gamma radiation logs at PR8 and PR10 below research basin, Montebello Forebay, Los Angeles County, 

California.
Chapter 3: Geologic and Hydrologic Setting 19

Vertical hydraulic conductivities calculated on 

the basis of these permeameter measurements ranged 

from 0.8 to 87.6 ft/d (fig. 8). The very low value nearest 

the floor of the research basin reflects accumulation of 

a thin layer of fine-grained, organic-rich sediment on 

the floor of the basin (an infiltration layer). Although 

thin, and probably of variable effective thickness, this 

material exerts a strong influence on the rate at which 

percolation occurs during a recharge experiment. 

Higher values of hydraulic conductivity in the 

percolation zone beneath the basin are likely to more 

closely approximate conditions in shallow parts of the 

aquifer.

An infiltration/percolation test was done at the 

research basin when the hydraulic conditions were 

similar to those that prevailed during the second of 

three recharge experiments. Reclaimed water was 

pumped into the research basin until the basin was full, 

after which the pump was turned off and the water 

drained in 3 days. The volume of water that infiltrated 

into the ground during the 3-day period was slightly 

less than 2 acre-ft. The surface area of the pond is about 

8,250 ft2 (dimensions about 75 by 110 ft); therefore, 

the rate at which reclaimed water infiltrated the 

research-basin floor is between 2 and 3 ft/d, equivalent 

to a water-transport rate (adjusted for porosity as 

discussed in the following section) of 8 to 12 ft/d 

through the soil if no lateral movement (mounding or 

advection) were to occur. The fact that a period of only 

about 2 days was required to replace preexisting soil 

moisture to a depth of 20 ft, as discussed in subsequent 

sections on water-quality changes during recharge, 

indicates that no more than a small increase occurs in 

the size of the recharge plume (assuming only 

mounding with no mixing or advection) after 2 days.

Horizontal Hydraulic Conductivity

Analysis of grain-size distributions, using the 

physicoempirical model of Arya and Paris (1981), 

yielded a preliminary estimate for horizontal hydraulic 

conductivity of 230 ft/d with a net porosity of 0.24 

(T.F. Rees, USGS, written commun., 1995).

Subsequently, slug tests were done to determine 

more reliable values for horizontal hydraulic 

conductivity at the research basin. The tests were done 

by recording water-level changes following 

displacement of a known volume of water by lowering 

a PVC pipe into monitoring well PR9, located at the 

center of the research basin and above the clay lens. 

Water-level changes were measured every second by 

means of a CR-10 data logger. The resulting data were 

analyzed using the Geraghty and Miller, Inc., Reston, 

Virginia, computer program AQTESOLV and the 

Bouwer-Rice straight-line solution for an unconfined 

aquifer. The analysis yielded horizontal hydraulicconductivity values that ranged from 85 to 125 ft/d. 

The method used and its inherent limitations are 

discussed by Anders (1997).

Hydraulic Conditions During the Recharge 

Experiments

Periodic water-level measurements were made 

between January 1993 and December 1995, and the 

results are given in appendix 1. Included in the table 

are measurements made from the monitoring wells and 

well points installed at the research basin and from 

monitoring wells (2S/11W-18P1, -19C1, -19E1, -24R1, 

and -25Q1) downgradient and south of the research 

basin.
20 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Figure 8. Vertical hydraulic conductivity of core material from selected depths beneath the research basin, Montebello Forebay, Los Angeles County, 

California.

HYDRAULIC CONDUCTIVITY, IN FEET PER DAY

0.1 1 10 100 1,000

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

1

2

3

4

5

6
Chapter 3: Geologic and Hydrologic Setting 21

As shown in appendix 1, the depth to water 

varied at the research basin; the water table was near 

(within about 1 ft) of the floor of the basin during the 

first two recharge experiments, whereas an 8- to 

12-foot unsaturated zone existed beneath the basin 

floor at the time of the third recharge experiment 

(fig. 9). The volume of water added during each of 

these recharge experiments was 2.1, 12.5, and 

25.6 acre-ft, respectively. Although standing water was 

present in the adjacent spreading grounds (which 

includes the settling basin immediately east and south 

of the research basin) during each of the first two 

recharge experiments, actual delivery of water in 

substantial quantities to the spreading grounds was 

occurring only during the first experiment and this 

apparently limited the volume of reclaimed water that 

could be infiltrated at the research basin during the 

experiment. The differing hydraulic conditions that 

prevailed at the research basin during the three recharge 

experiments probably represent the range in 

biogeochemical conditions that occur, with the second 

experiment representing intermediate conditions, as 

discussed in greater detail in chapter 5, “Changes in 

Common Chemical Constituents During Recharge.”

Experiment 1

August 10–30, 1993 Experiment 2

April 4–June 1, 1994

Experiment 3

September 6–23, 1994

Percolation Test

July 28–30, 1995

DEPTH OF WATER LEVEL, ABOVE OR BELOW BASIN FLOOR, IN FEET

10

0

10

20

JAN APR JUL OCT JAN APR JUL OCT JAN APR JUL OCT JAN

140

150

160

170

Water level in well PR9

Floor of research basin

1993 1995 1994

ALTITUDE OF WATER LEVEL, IN FEET

Figure 9. Depth and altitude of water level at the research basin, Montebello Forebay, Los Angeles County, California, January 1993–December 1995.
22 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 4: MICROBIOLOGICAL CHANGES 

DURING RECHARGE

By Robert Anders and Roy A. Schroeder

Although the primary focus of analyses during 

recharge experiments at the research basin was on 

chemical constituents, some analyses also were done 

for microorganisms. These included coliform bacteria 

and groups of bacteria commonly involved in nitrogen 

oxidation and reduction transformations. Although 

coliform bacteria and nitrogen concentrations generally 

have not been a problem in production wells from the 

area, both are regulated relative to the use of reclaimed 

water for ground-water recharge by the California 

Regional Water Quality Control Board under Title 22 

of the California Administrative Code.

Methods

Core and water samples were collected for 

enumerating total and fecal coliform bacteria, 

nitrifying, and nitrate-reducing and denitrifying 

bacteria. Core samples were collected in January 1993. 

Water samples were collected during the first two of 

the three recharge experiments—in August 1993 and 

April–June 1994. Water samples were collected from 

the pipeline (PR13) that supplies wastewater effluent 

(recycled water) to the research basin, from the pond 

that developed in the research basin itself (PR12), from 

the recycled water percolating through the research 

basin using sampling ports of the multiple-level 

sampler beneath the basin, and from monitoring wells 

in and around the research basin.

Core samples were collected by driving a flamesterilized, split-spoon core barrel through the bottom of 

the hole produced by hollow-stem augering. Samples 

were collected to a depth of about 45 ft below the top of 

the berm on the south side of the research basin (about 

35 ft beneath the basin floor). The core material was 

placed in sterile polyethylene “Whirl-Pak” bags and 

stored at 4oC in the dark until analysis within 24 hours. 

The cores were analyzed for total and fecal coliform 

bacteria by the filter membrane procedure, and for 

nitrifying, and for nitrate-reducing and denitrifying 

bacteria by the most probable number (MPN) method 

as described by Britton and Greeson (1987).

Water samples collected in August 1993 were 

placed in sterile 50-mL bottles and stored at 4oC until 

analysis later the same day in the laboratory. The 

samples were analyzed for total and fecal coliform 

bacteria and for nitrate-reducing and denitrifying 

bacteria. The MPN method was used to enumerate total 

and fecal coliform bacteria as described by Britton and 

Greeson (1987). The method was modified by 

substituting lactose broth for lauryl tryptose broth 

owing to the possible presence of stressed coliform 

bacteria. All the fermentation tubes that were positive 

for gas (carbon dioxide) production, heavy growth, or 

an acidic reaction were transferred into brilliant green 

lactose broth (BGLB) and EC broth. Those tubes that 

were positive for gas production in the BGLB were 

reported as containing coliform bacteria, and those 

tubes that were positive for gas production in the EC 

broth were reported as containing fecal coliform 

bacteria. For the samples collected August 16 and 

August 23, only the 10-mL-dilution fermentation tubes 

were used, and therefore those results are recorded as 

either detected (+) or not detected (−) for total and fecal 

coliform bacteria.

The nitrate-reducing and denitrifying bacteria 

were enumerated using a three-tube MPN method with 

six five-tube decimal (10X) dilutions modified from 

Britton and Greeson (1987). Nearly all tubes that 

yielded a positive test for nitrate-reducers also tested 

positive for denitrifying bacteria; therefore, those 

results are combined as a single MPN in the data tables. 

All water samples collected August 16 and three 

samples collected August 23 were discarded owing to 

contamination of the nitrate broth, and one sample 

collected August 30 was discarded before final results 

were recorded.

Water samples collected in April 1994 during the 

second recharge experiment were analyzed for total 

and fecal coliform bacteria, for nitrifying (ammoniaand nitrite-oxidizing) bacteria, and for nitrate-reducing 

and denitrifying bacteria. The membrane filter 

procedure as described in AWWA (1992) was used for 

enumerating total and fecal coliform bacteria. The 

samples were collected in 250-mL sterile bottles, and 

thiosulfate tablets were added to remove any possible 

influence from chlorine. Several samples collected 

April 6, 1994, were too numerous to count (TNTC), 

prohibiting the development of the characteristic green 

sheen associated with the presence of total coliform 

bacteria or the blue colony color associated with fecal 

coliform bacteria.
Chapter 4: Microbiological Changes During Recharge 23

The nitrate-reducing and denitrifying bacteria 

were enumerated by the same procedure used for the 

August 1993 sampling, and the procedure to enumerate 

the nitrifying bacteria was modified to include three 

five-tube 10X dilutions.

Bacterial Distributions in Cores

The distribution of fecal coliform, nitrifying 

(ammonia- and nitrite-oxidizing), and nitrate-reducing 

and denitrifying bacteria from selected cores beneath 

the research basin is given in table 3. No fecal coliform 

bacteria were detected within the soil column.

There is some evidence that ammonia-oxidizing 

bacteria are more abundant at shallower than at greater 

depths, although most reported bacterial densities are 

near the measurement detection limits. Nitriteoxidizing bacteria also were detected in about half the 

core samples. The density of nitrate-reducing and 

denitrifying bacteria varied by as much as two orders of 

magnitude throughout the soil column and was 

generally at least two orders of magnitude greater than 

the densities of nitrifying bacteria.

Table 3. Distribution of selected bacteria in cores beneath the research basin, Montebello Forebay, Los Angeles County, California

[Depth, in feet below bottom of research basin; cfu, colony forming units; MPN/g, most probable number per gram; <, less than indicated value]

Depth Fecal 

coliform

(cfu)

Ammoniaoxidizing

(MPN/g wet soil)

Nitriteoxidizing

(MPN/g wet soil)

Nitrate-reducing/

denitrifying

(MPN/g wet soil) From To

2.8 3.9 <1 930 230 93,000

4.0 4.8 <1 2,300 2,300 210,000

4.8 5.6 <1 230 <30 4,300

5.6 6.2 <1 390 230 93,000

6.2 7.0 <1 230 <30 9,300

7.0 8.0 <1 230 <30 240,000

8.5 9.7 <1 430 150 23,000

10.0 11.5 <1 230 430 240,000

11.5 12.9 <1 230 230 1,100,000

13.0 14.2 <1 230 40 240,000

30.5 31.4 <1 230 90 460,000

31.4 32.0 <1 <30 <30 90

32.0 32.2 <1 <30 <30 9,300

32.17 32.25 <1 <30 <30 15,000

32.25 32.8 <1 <30 <30 43,000

33.0 33.5 <1 <30 <30 460,000

34.3 34.8 <1 <30 <30 460,000
24 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Total and Fecal Coliform in Water

Results of weekly measurements for total and 

fecal coliform densities in water from the multilevel 

sampler and from piezometers during the first recharge 

experiment in August 1993 are shown in table 4. 

Numbers varied considerably during the first 3 weeks 

after recharge began, with the greatest change 

occurring in samples from the second week. Total 

coliform detections beneath the research basin 

increased from two samples on August 10 to 9 samples 

on August 16, 5 days after recharge stopped. Fecal 

coliform detections increased from none to three 

samples during the same period. On August 23, 12 

days after filling of the research basin was 

discontinued, detection had fallen to two samples for 

total coliform and to none for fecal coliform. By 

August 30, no detections were found for total and fecal 

coliform.

Densities of total and fecal coliform bacteria in 

water below the research basin are shown in table 5 for 

immediately before recharge, 2 days after the second 

recharge experiment began in April 1994, and more 

than 1 month after recharge was discontinued. The data 

show that there was a rapid buildup of both total and 

fecal coliform soon after recharge began, and then a 

return to nondetectable levels after recharge was 

discontinued. This rapid increase from nondetectable 

levels in both the soil and water prior to recharge to 

detectable levels in the water after recharge suggests 

that some mechanism (for example, direct physical 

transport with the percolating reclaimed water) other 

than simple grow-back of preexisting bacteria is 

operating. More extensive study would be needed to 

confirm a mechanism and source. Although a similar, 

but far less distinctive, pattern appears to exist for 

nitrogen-transforming bacteria, as discussed in the 

following section, it is more likely that those results are 

largely explained by stimulation of natural populations 

as fresh recycled water reaches the underlying soil.

Table 4. Distribution of total coliform and fecal coliform bacteria during August 1993 recharge experiment at research basin, Montebello Forebay, Los 

Angeles County, California

[MPN, most probable number; mL, milliliter; +, detected; −, not detected; —, no data; coliform data given left of slash, fecal coliform data given right of slash; 

see table 1 for sample identifier]

Sample

identifier

Total coliform/fecal coliform

Aug. 10

(MPN/100mL)

Aug. 16

(+ or -)

Aug. 23

(+ or -)

Aug. 30

(MPN/100mL)

MLS4 −/− +/− −/− −/−

MLS5 −/− +/+ −/− −/−

MLS6 −/− +/− −/− −/−

MLS7 −/− +/− +/− −/−

MLS9 2/− +/− −/− −/−

MLS11 −/− +/+ +/− −/−

MLS13 −/− +/+ −/− −/−

MLS15 −/− −/− −/− −/−

MLS19 2/− +/− −/− −/−

PR8 −/− +/− −/− −/−

PR9 −/− −/− −/− —

PR10 −/− −/− −/− −/−

PR11 −/− −/− −/− −/−

PR12 80/− +/+ +/− −/−

PR13 —/− −/− −/− −/−
Chapter 4: Microbiological Changes During Recharge 25

Nitrogen-Transforming Bacteria in Water

Nitrifying bacteria in water samples from 

beneath the research basin were analyzed only during 

the second recharge experiment. Both ammoniaoxidizing and nitrite-oxidizing bacteria were detected 

(table 6) in most samples before, during, and after 

recharge; densities clearly increased with depth (but 

perhaps only slightly at shallower depths) soon after 

recharge. 

Nitrate-reducing and denitrifying bacteria were 

abundant in the reclaimed water itself. Values of MPN 

were about 104 per mL in the research basin (PR12) 

and in the effluent (PR13) during the first recharge 

experiment in August 1993 (table 7A), and values were 

similar during the second recharge experiment in 

April–June 1994 (table 7B). The numbers decrease by 

about an order of magnitude in both the effluent 

(PR13) and the research basin (PR12) during the 

experiment and also decrease by about an order of 

magnitude in percolating water taken from the 

multilevel sampler beneath the basin. The decrease 

could be due to removal on soil and (or) die-off. The 

numbers from the multilevel sampler (table 7A) were 

generally highest in the August 23 samples during the 

first recharge experiment but only slightly higher than 

those collected during the recharge before and after 

this date. Data collected during the second experiment 

indicate that background bacterial densities beneath 

the research basin decline by one-to-two orders of 

magnitude when recharge is not occurring (compare 

data in table 7B, from April 6, 2 days after recharge 

commenced, to June 1, 41 days after recharge was 

discontinued).

No strongly discernible pattern with depth is 

apparent for denitrifiers during either recharge 

experiment (fig. 10). In fact, the August 1993 data 

(table 7A) indicate slightly higher numbers for 

piezometers screened below the clay lens (PR8 and 

PR10), and therefore unaffected by recharge from the 

research basin, than for piezometers screened above 

the clay lens (PR9 and PR11). The deeper piezometers 

also contain much higher manganese concentrations 

(appendixes 2 and 3), indicating a more reducing (less 

oxidizing) environment that may be conducive to 

maintaining high “natural” bacterial levels in areas or 

depths not affected by recharge from the research 

basin. It seems clear from these results that nitratereducing and denitrifying bacteria are ubiquitous, in 

both reclaimed water and in ambient (preexisting) 

water at the research basin.

Table 5. Distribution of total coliform and fecal coliform bacteria in water 

below the research basin, Montebello Forebay, Los Angeles County, 

California, during April/June 1994 recharge experiment 

[CFU, colony forming units; mL, milliliter; −, not detected; —, no data; 

TNTC, too numerous to count; coliform data given left of slash, fecal 

coliform data given right of slash; see table 1 for sample identifier]

Total coliform/fecal coliform

Sample

identifier April 4

April 6

June 1

CFU/100mL)

MLS4 −/− 10/2 −/−

MLS5 −/− 18/2 −/−

MLS6 −/− 11/2 −/−

MLS7 −/− 8/2 −/−

MLS8 −/− 28/1 −/−

MLS9 −/− TNTC/18 −/−

MLS10 −/− 19/6 −/−

PR9 −/− 9/− −/−

PR12 —/— TNTC/16 —/—

PR13 —/— TNTC/— —/—
26 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Table 6. Distribution of ammonia-oxidizing and nitrite-oxidizing bacteria in water below research basin, Montebello Forebay, Los Angeles County, California, 

during April/June 1994 recharge experiment

[MPN, most probable number; mL, milliliter; −, not detected; —, no data; see table 1 for sample identifier]

Sample

identifier

Ammonia-oxidizing Nitrite-oxidizing

Apr. 4 Apr. 6 Jun. 1 Apr. 4 Apr. 6 Jun. 1

(MPN/mL)

MLS4 330 490 − 700 80 790

MLS5 490 790 40 80 330 170

MLS6 790 330 20 230 230 230

MLS7 1,300 2,400 80 1,700 230 230

MLS8 1,300 1,300 50 490 230 230

MLS9 − 490 − 20 140 50

MLS10 − 490 − 20 80 80

PR9 − − 230 − 20 230

PR12 —/— 24,000 —/— —/— 490 —/—

PR13 —/— 2,400 —/— —/— 1,300 —/—

Table 7A. Distribution of nitrate-reducing and denitrifying bacteria in water 

below research basin, Montebello Forebay, Los Angeles County, California, 

during August 1993 recharge experiment

[MPN, most probable number; mL, milliliter; —, no data; see table 1 for 

sample identifier]

Sample

identifier

Aug. 10 Aug. 23 Aug. 30

(MPN/mL)

MLS4 7,900 — 790

MLS5 49,000 — 790

MLS6 49,000 — 490

MLS7 3,300 4,900 1,300

MLS9 1,700 4,900 240

MLS11 330 1,400 1,400

MLS13 1,700 2,800 790

MLS15 790 1,300 330

MLS19 3,300 2,200 1,700

PR8 490 330 2,200

PR9 130 310 260

PR10 180 220 4,900

PR11 3,300 170 790

PR12 49,000 1,400 3,500

PR13 33,000 3,300 17,000

Table 7B. Distribution of nitrate-reducing and denitrifying bacteria in 

water below research station, Montebello Forebay, Los Angeles County, 

California, during April/June 1994 recharge experiment

[MPN, most probable number; mL, milliliter; —, no data; see table 1 for 

sample identifier]

Sample

identifier

Apr. 4 Apr. 6 June 1

(MPN/mL)

MLS4 1,700 1,400 790

MLS5 790 2,700 790

MLS6 1,400 49,000 230

MLS7 1,100 1,100 330

MLS8 460 1,700 70

MLS9 130 33,000 700

MLS10 4,900 2,400 340

PR9 4,900 700 1,700

PR12 —/— 24,000 —/—

PR13 —/— 23,000 —/—
Chapter 4: Microbiological Changes During Recharge 27

Figure 10. Distribution of nitrate-reducing and denitrifying bacteria at the research basin, Montebello Forebay, Los Angeles County, California, during 

recharge experiments (data from PR12 at surface, multilevel sampler at 4 to 20 feet, PR9 at 25 feet, and PR8 at 50 feet).

MOST PROBABLE NUMBER PER MILLILITER (MPN/ML)

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

10 1 10 2 10 3 10 4 10 5 10 6 10 7

0

10

20

30

40

50

8/10/93

8/24/93

8/31/93

6/1/94

Sample date —

month/day/year

4/4/94

4/6/94
28 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 5: CHANGES IN COMMON 

CHEMICAL CONSTITUENTS DURING 

RECHARGE

By Roy A. Schroeder and Robert Anders

As indicated earlier (fig. 9), reclaimed water was 

discharged to the research basin on three occasions: 

from 10:45 a.m., August 10, to 3:35 p.m., August 11, 

1993; from 8:00 p.m., April 4, to 5:00 p.m., April 21, 

1994; and from 5:35 p.m., September 6, to 5:15 p.m., 

September 23, 1994. The volume of water added 

during each to these recharge experiments was 2.1, 

12.5, and 25.6 acre-ft, respectively. The local water 

table was approximately coincident with the floor of 

the research basin when the first two recharge 

experiments began, and as much as 15 ft below the 

floor of the research basin during the third experiment 

(fig. 9).

The primary objective for the first experiment 

was to test operation of the instrumentation. Many 

more (greater than 150) water-quality samples were 

collected during the second experiment, and they were 

analyzed for a much broader suite of inorganic, 

isotopic, and organic constituents. For this reason, most 

of the data analysis is focused on the second 

experiment. The third experiment was to confirm 

results from the second experiment for organic 

compounds of wastewater origin. In this chapter of the 

report, results are discussed for selected water-quality 

constituents, particularly nitrogen and organic carbon; 

and the results for characterization and analysis of 

organic matter are discussed in several chapters 

following this chapter.

Methods for Common Chemical Constituents

Samples for analysis of common inorganic 

water-quality constituents were obtained using 

peristaltic (shallow) or submersible (deep) pumps and 

composited in an 8-L high-density polyethylene churn 

splitter, pressure filtered through a 0.45-μm cellulose 

acetate membrane, and distributed into glass or 

polyethylene bottles for any additional preservation 

and storage. Aliquots for analysis of major cations and 

trace metals (inorganic priority pollutants) were 

preserved by addition of nitric acid to approximately 

pH 2. Aliquots for nutrients were preserved with 

mercuric chloride and chilled to 4oC pending analysis 

within a few days of collection. Samples for analysis of 

dissolved organic carbon were collected and processed 

separately from those for inorganic constituents by 

nitrogen-pressure filtration through a 0.45-μm silver 

membrane housed in a 200-mL stainless steel canister. 

(Procedures used to obtain and process samples for 

detailed analysis of organic carbon are discussed in the 

applicable chapters in the second part of this report.)

Major cations, trace elements, and nutrients were 

analyzed by the USGS National Water Quality 

Laboratory (NWQL) in Arvada, Colorado (Timme, 

1994), using methods described by Fishman and 

Friedman (1989). Anions shown in appendix 5, 6, 

and 7 were analyzed locally by the USGS San Diego 

Geochemistry Laboratory using high-pressure ion 

chromatography. Water isotopes were analyzed by the 

USGS Isotope Laboratory in Reston, Virginia, using 

methods described by Epstein and Mayeda (1953), 

Kendall and Coplen (1985), and Coplen (1988), and 

results are reported in per mil (o/oo) using the standard 

delta (δ) notation (Craig, 1961a, b). Several nitrogenisotope analyses on nitrate and a few on ammonia were 

done by a contract laboratory for the USGS National 

Water Quality Laboratory. Organic carbon was 

analyzed by one of this report's authors (L. B. Barber) 

using a heated persulfate oxidation method. Specific 

conductance, pH, alkalinity, (titration to pH = 4.5), 

water temperature, dissolved molecular oxygen 

(Winkler titration), and chlorine (Hach colormetric 

comparison) were determined in the field immediately 

after sample collection. The results from all analyses 

are compiled in tables in appendixes at the end of this 

report, and analyzed constituents are listed in table 8. 
Chapter 5: Changes in Common Chemical Constituents During Recharge 29

Chemical Attenuation During Recharge

Recognition that hydraulic and chemical 

processes at the research basin are influenced by 

recharge operations at the adjacent San Gabriel River 

Coastal Spreading Grounds is essential to the 

interpretation of water-quality changes that occur 

during recharge experiments at the research basin. The 

hydraulic influence is readily apparent from the waterlevel measurements, and the effect on chemical 

composition is also apparent from differences in majorion composition on April 4, 1994, when, just prior to 

initiation of the second recharge experiment, sulfate 

and chloride concentrations (fig. 11) in piezometers at 

depths of 25 and 50 ft beneath the research basin 

(PR8, 9, 10, and 11) fall between concentrations in an 

upgradient (background) monitoring well 

(2S/11W-7J1) and the recycled-water effluent (PR13). 

More conclusive confirmation of chemical changes 

comes from identification of specific organic 

compounds of wastewater origin prior to recharge. 

Accordingly, the chemical composition of soil moisture 

beneath the research basin prior to recharge is 

influenced by timing and quantity of prior recharge 

from both natural [stormwater and (or) imported water] 

and artificial (reclaimed water) sources.

Water-quality samples were collected at the 

research basin on April 4, 1994 (day 0), just prior to 

filling the research basin; April 5–8 (including multiple 

samples for some days); April 21 (day 17), the last day 

reclaimed water was added to the research basin; and 

June 1 (day 58), almost 6 weeks after flow to the 

research basin was halted. The results of these analyses 

are given in tables in the appendixes, and selected data 

used in the discussion that follows are reproduced in 

figures and tables that are incorporated in the text.

Mixing and Displacement During Recharge

A two-component mixing model using chloride 

as the conservative tracer was chosen to evaluate the 

displacement, or mixing, of preexisting soil moisture as 

the recycled water percolated beneath the floor of the 

research basin. The fraction (ƒ) of recycled water in the 

research basin (PR12) that is present in samples from 

the multilevel sampler (MLS) and from monitoring 

wells (PR8, 9, 10, and 11) is calculated using the 

equation:

ƒ = (C − C0) / (CPOND − C0),

where 

C0 is the concentration prior to recharge,

C is the concentration at selected sampling 

times after the recharge experiment 

began, and

CPOND is the average concentration in reclaimed 

water standing in the research basin 

(PR12) during the course of the recharge 

experiment. 

Table 8. Inorganic, isotopic, and field constituents analyzed for this study, Montebello Forebay, Los Angeles County, California

Field data Major ions Nutrients Minor

elements

Trace 

elements

Isotope

ratios

Conductance Calcium Nitrate Fluoride Arsenic Hydrogen

pH Magnesium Nitrite Bromide Beryllium Nitrogen

Temperature Sodium Ammonia Silica Cadmium Oxygen

Oxygen Potassium Phosphate Barium Chromium

Alkalinity Sulfate Boron Cobalt

Chlorine Chloride Iron Copper

Lithium Lead

Manganese Molybdenum

Strontium Nickel

Silver

Vanadium

Zinc
30 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Use of this rather simple calculation is possible 

only because chemical composition of the effluent in 

the pond (PR12) remained fairly constant during the 

entire period of the second recharge experiment. Mean 

and standard deviations for selected constituents in the 

basin itself (PR12) during the first 3 days after filling 

with effluent began were: chloride = 

133.6 ± 4.2 mg/L (n = 18); nitrate-N = 6.0 ± 0.4 mg/L 

(n = 17); nitrite-N = 1.5 ± 0.2 mg/L (n = 17); 

ammonia-N = 4.7 ± 0.6 mg/L (n = 17); and total 

(inorganic) nitrogen = 12.2 ± 0.8 mg/L (n = 17). By 

comparison, there was much greater variability during 

the third recharge experiment in September 1994 when 

chloride concentration was 130 ± 14 mg/L 

(calculations from data in appendixes 3 and 4).

7J1

PR8

PR9 PR10

PR11

PR13

CHLORIDE CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

SULFATE CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

0 12345

0

1

2

3

4

5

CHLORIDE CONCENTRATION, IN MILLIGRAMS PER LITER

SULFATE CONCENTRATION, IN MILLIGRAMS PER LITER

200

50

0

0 50 100 150

100

150

250

Figure 11. Effect of recycled water on ground-water composition at the research basin, Montebello Forebay, Los Angeles County, California (7J1, 

background well; PR8, 9, 10, and 11, piezometers at the research basin; and PR13, wastewater effluent).
Chapter 5: Changes in Common Chemical Constituents During Recharge 31

It is recognized that the mixing model is an 

oversimplification, especially during the initial period 

of recharge when hydraulic conditions are still far from 

steady state, because percolation of recycled water is 

actually a continuous process similar to piston flow in 

which the percolating water that displaces preexisting 

soil moisture at a given depth is actually a mixture of 

soil moisture transported from above (rather than the 

instantaneous concentration before recharge). The 

simple model could be replaced with a transient onedimensional (depth-dependent) transport and mixing 

model if data collection were much more frequent 

during the rapidly changing early period of recharge. 

Nevertheless, the simple model is useful for illustrating 

temporal and depth-related concentration patterns 

resulting from constituent transport and removal 

efficiencies as discussed below.

Soon after recharge from the research basin 

begins, chloride at the multilevel sampling ports and 

the 25-foot piezometers (PR9 and 11) increases from 

preexisting levels near 100 mg/L to the 130–140 mg/L 

concentration that exists in the research basin. 

Displacement of preexisting water is virtually complete 

(ƒ = 1) within 2 days at the 5, 10, and 15-foot 

multilevel ports; and within 3 to 4 days at a depth of 

25 ft—slightly sooner beneath the research basin (PR9) 

than just outside the research basin (PR11)

(figs. 12A, B). In fact, in some cases the calculated 

value for ƒ exceeds 1, which would imply a 

contribution greater than 100 percent. A value greater 

than 1 could indicate dissolution and downward 

transport of desiccated salt by the “first flush” of 

recharge. However, this conclusion should be 

considered as tentative because natural variability in 

the research basin (PR12) coupled with analytical 

imprecision translate to an uncertainty of about ± 0.2 

for individual values of ƒ. Precision in calculated ƒ

values would be improved if differences in chloride 

concentration between preexisting soil water and the 

percolating recharge (effluent) were greater. However, 

such differences often are likely less than those that 

prevailed at the time of this experiment in April 1994, 

which was soon after the period of winter rains that 

would be expected to result in comparatively fresher 

water in shallow soil zones beneath the basin.

Hydrogen- and oxygen-isotope ratios confirm 

the observation that displacement of preexisting water 

is rapid and nearly complete, although fewer data exist 

for these isotopes than for chloride. As recharge 

proceeds, preexisting soil water that is isotopically 

heavier [δD about –55 per mil (o/oo]), δ18O about −7.7 o/oo] is displaced by isotopically lighter water (fig. 13). 

As shown in figure 13, the isotope ratios do not become 

quite as negative (isotopically light) as the effluent 

itself (PR13), for which δD = −62.7 o/oo and 

δ18O = −8.65 o/oo, perhaps due to slight enrichment in 

deuterium and oxygen-18 during evaporation from 

water standing in the research basin itself (PR12). 

Isotopic analyses were not obtained for recycled water 

in the research basin.

The percent removal for other constituents in the 

percolating water can be calculated by comparing 

measured concentrations to “predicted” concentrations 

based on conservative behavior for chloride. The values 

of ƒ obtained from chloride data are used to calculate 

these predicted concentrations. For times long after 

recharge has begun, such that hydraulic steady state 

prevails beneath the basin (ƒ = 1), removal efficiency is 

a simple comparison of concentration in the sample 

with average concentration in the research basin. 

However, to obtain removal estimates for the early 

period of recharge, before steady state is established 

and at depths below which displacement is complete 

(ƒ < 1), predicted concentrations (CPRED) for the 

nonconservative constituent first must be calculated 

from

CPRED = ƒ CPOND + (1 − ƒ) C0,

where 

The measured concentration from individual 

samples collected at different times is then compared 

with the predicted concentration to obtain percent 

removal of selected constituents for each sample.

C0 is the concentration prior to 

recharge, 

CPOND is the average concentration in 

reclaimed water in the research 

basin, and 

values of ƒ were obtained from chloride data. 
32 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

TIME SINCE RECHARGE BEGAN, IN DAYS

0 10 20 30 40 50 60

f, FRACTION OF CHLORIDE FROM "RECYCLED" WATER

0.0

0.1

0.2

0.4

0.6

0.8

1.0

1.2

MLS5

MLS10

MLS15

PR8

PR9

PR11

B

TIME SINCE RECHARGE BEGAN, IN DAYS

0246 8 10 12 14 16 18 20

f, FRACTION OF CHLORIDE FROM RECYCLED WATER

0.0

0.1

0.2

0.4

0.6

0.8

1.0

1.2

MLS5

MLS10

MLS15

PR9

PR11

A

Figure 12. Displacement of preexisting chloride at multilevel samplers (MLS, at indicated depths in feet) and piezometers (PR9 and 11, above the clay lens; 

PR8, below the clay lens) beneath the research basin, Montebello Forebay, Los Angeles County, California, as the basin is filled with recycled water for the 

periods up to (A) 17 days and (B) during the subsequent drying cycle.
Chapter 5: Changes in Common Chemical Constituents During Recharge 33

Nitrogen

 Results from these calculations for nitrogen are 

shown in figure 14. To remove the considerable 

variability, some of which may reflect real differences 

in a rapidly evolving system and some which is due to 

analytical imprecision, results from all depths sampled 

by the multilevel sampler at a given time were 

combined to obtain averages that are plotted in the 

figure. The total-nitrogen values used in the 

calculations are, in fact, based on analyses of inorganic 

species only (ammonium, nitrate, and nitrite)—organic 

nitrogen was not analyzed. The error introduced by this 

omission is not known and may be somewhat variable 

given the ease with which microorganisms interconvert 

ammonia and proteinaceous organic nitrogen. A single 

sample of effluent taken from PR13 in May 1996 had a 

dissolved organic nitrogen concentration of only 

0.9 mg/L, which represented a little less than 10 

percent of total inorganic nitrogen present. 

DELTA OXYGEN-18, IN PER MIL

–10 –9 –8 –7 –6 –5 –4

–70

–65

–60

–55

–50

–45

–40

2S/11W-7J1,

(Background)

PR13

(Reclaimed water)

DAY 0

(Before recharge)

DAY 2

(During recharge)

DAY 58

(After recharge)

DELTA DEUTERIUM, IN PER MIL

Global meteoric-water line (Craig, 1961a)

Figure 13. Displacement of preexisting water (day 0) beneath the research basin, Montebello Forebay, Los Angeles County, California, as the research 

basin is filled with recycled water and then its return to prior isotopic composition about 6 weeks after recharge is discontinued (day 58).
34 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Results summarized in figure 14 indicate that 

nitrogen removal in the multilevel sampler rises rapidly 

to about 30 percent after 3 days, and then increases 

more slowly to about 60 percent on the 17th and last 

day that recycled water was added to the research 

basin. Samples for which only a small fraction (ƒ < 0.2) 

of recharged water is present are omitted from the 

calculation because they yield very large computational 

anomalies. This occurs in samples collected from 

shallow depth soon after recharge, and for a somewhat 

longer period in samples from deeper levels. 

Calculations based on samples from a single depth are 

subject to very high uncertainty; therefore, the low (10 

percent) and high (30 percent) ends of the range for the 

25-foot piezometers (PR9 and 11) may themselves not 

be different. However, lower removal rates in the 

deeper ports of the multilevel sampler do provide 

additional evidence for less removal at greater depth.

TIME SINCE RECHARGE BEGAN, IN DAYS

0 10 20 30 40 50 60

PERCENT NITROGEN REMOVAL

0

20

40

60

80

100

MLS4–20

PR9 and 11

Figure 14. Removal of nitrogen beneath the research basin, Montebello Forebay, Los Angeles County, California, as the research basin is filled with 

recycled water (MLS4–20, average for multilevel sampler; PR9 and 11, average for piezometers above the clay lens).
Chapter 5: Changes in Common Chemical Constituents During Recharge 35

It is important to note that the actual percentages 

are less important than is the fact that a large amount of 

nitrogen removal occurs during (and after) recharge. 

On the basis of additional chemical and isotopic 

evidence that is discussed later, the processes leading to 

decreased concentrations are likely to take place during 

any recharge experiment in the research basin, and 

during regional spreading of recycled water as well. 

Actual removal rates differ somewhat under different 

environmental and operational conditions. For 

example, the low infiltration rate and resultant more 

stagnant conditions that prevailed during the first 

recharge experiment led to almost complete removal of 

nitrogen, as well as low oxygen and high manganese 

concentrations (covariance of these constituents is 

explained in the section “Chemical and Isotopic 

Evidence for Denitrification”).

Organic Carbon

Organic carbon (fig. 15) also is removed during, 

and after, recharge. Fewer concentration data exist for 

organic carbon than for nitrogen. The measured 

concentration of dissolved organic carbon in the 

research basin was 9.18 mg/L on the second day of 

recharge. Calculations based on samples for which 

chloride indicates sufficient recharge water is present to 

justify computation (ƒ > 0.2) yield an average removal 

of slightly less than 35 percent after 2 days and slightly 

more than 35 percent thereafter. However, the range in 

removal, from 21 to 59 percent, is quite large, and the 

highest removals occurred at intermediate depths. 

(Organic carbon removal is discussed in more detail in 

the second part of this report.)

Zinc

Zinc is the last constituent for which removal 

efficiencies were calculated in the manner described 

above. It was the only inorganic trace metal found to be 

present at levels much higher than detection limits in 

the recycled water and elevated above natural levels. 

Zinc is abundant in urban environments (Schroeder, 

1995, and references therein) and in reclaimed water as 

indicated by its mean concentration of 48 μg/L (range 

from 41 to 58 μg/L) in the research basin (PR12) 

during the second recharge experiment. Percent 

removal, plotted in figure 16 and concentration data 

(though highly variable), given in appendix 3, show 

that downward transport of zinc is somewhat efficient 

initially, especially at the shallowest ports of the 

multilevel sampler. However, removal percentage 

exceeds 70 percent by the 17th and last day of recharge. 

On the basis of these results, it is concluded that zinc is 

not a suitable tracer of reclaimed-water movement over 

long distances and traveltimes.

Arsenic

The maximum contaminant level (MCL) of 

50 μg/L for arsenic in drinking water will be lowered to 

10 μg/L in the next few years. Analysis of 23 samples 

of reclaimed water from PR12 and PR13 (appendix 2) 

yields a mean dissolved arsenic concentration of only 

2.7 μg/L (highest concentration of 4 μg/L)—much less 

than even the reduced MCL. For that reason, the only 

analyses done for this study were those associated with 

the first recharge experiment in September 1993. 

Results of measurements taken from beneath the 

recharge basin found about 40 percent of almost 300 

samples had a concentration higher than 10 μg/L, but 

that none exceeded 50 μg/L. It also has been reported 

that 10 μg/L was exceeded in only about 7 percent of 

more than 100 ground-water monitoring samples from 

the Central and adjacent West Coast Basins (Land and 

others, 2002). Factors that can affect arsenic 

concentration include mineral composition of the local 

aquifer soil, speciation (inorganic or organic) of the 

element, sorption, and redox state. Without further 

study, it is not possible to ascertain which of these 

factors is most important; however, it is clear from low 

concentrations in the effluent that wastewater is not a 

direct source of arsenic in ground water. Furthermore, 

it appears that the arsenic mobilization that is observed 

over short distances in the recharge experiment does 

not occur over long distances, based on the results from 

Land and others (2002).
36 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

DISSOLVED ORGANIC CARBON CONCENTRATION, IN MILLIGRAMS PER LITER

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0246 8 10

0

5

10

15

20

25

30

DAY 0

DAY 2

DAY 58

PR12 (Research basin)

Figure 15. Change in dissolved organic carbon concentrations beneath the research basin, Montebello Forebay, Los Angeles County, California, before 

(day 0), during (day 2), and after (day 58) recharge with recycled water.
Chapter 5: Changes in Common Chemical Constituents During Recharge 37

Chemical and Isotopic Evidence for 

Denitrification

Differences in chemical concentrations between 

the reclaimed-water effluent before delivery to the 

research basin (PR13) and in the research basin itself 

(PR12) are small for nearly all constituents. The most 

notable exception is nitrogen. During the first recharge 

experiment in August 1993, concentrations (as 

nitrogen) in the effluent (PR13) were about 13 mg/L 

for ammonia, 3 mg/L for nitrate, and about 2 mg/L for 

nitrite over a period of about 20 days. Yet in the 

research basin itself (PR12), ammonia remained less 

than 1 mg/L, and nitrate plus nitrite was about 5 mg/L 

(appendix 2). No reason for the low ammonia 

concentration is known; however, the fact that the 

research basin was filled initially in about 1 day, and 

only sporadic additions were made thereafter to 

maintain a full basin, may have allowed sufficient algal 

growth to remove the ammonia (green color of the 

water quickly intensified as recycled water was added 

to the research basin).

TIME SINCE RECHARGE BEGAN, IN DAYS

0 10 20 30 40 50 60

0

20

40

60

80

100

MLS4–20

PR9 and 11

PERCENT ZINC REMOVAL

Figure 16. Removal of zinc beneath the research basin, Montebello Forebay, Los Angeles County, California, as the research basin is filled with recycled 

water (MLS4–20, average for multilevel sampler; PR9 and 11, average for piezometers above the clay lens).
38 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

A similar, but far less dramatic, shift to a greater 

proportion of nitrogen in the oxidized state as effluent 

accumulated in the research basin was observed during 

the second recharge experiment in April 1994. In this 

experiment, the research basin was filled with a much 

larger volume of reclaimed water (12.5 acre-ft over 17 

days in comparison with 2.1 acre-ft over 21 days in the 

first experiment). Replenishment with the much larger 

volume may have been responsible for keeping 

variability in concentrations low, although even in the 

second experiment there was a decrease in ammonianitrogen concentrations from about 5 mg/L during the 

first few days of recharge to a little more than 2 mg/L 

on the last (17th) day of recharge (fig. 17).

Nitrogen dominance continues its shift in the 

direction of oxidized species as reclaimed water 

infiltrates beneath the research basin (figs. 18A–H). 

Much of the shift reflects removal of ammonia, but the 

fact that nitrate plus nitrite concentrations in the 

multilevel sampler and the 25-foot piezometers reach 

levels during the first few days of recharge that are 

slightly higher than those in the research basin itself 

implies that some oxidation of reduced nitrogen must 

be taking place beneath the research basin. However, as 

recharge continues to day 17, concentrations of 

nitrogen decrease and there is a noticeable shift to 

higher ammonia abundance (fig. 18G). By 41 days 

after filling of the research basin was discontinued, 

ammonia actually predominates at the shallower depths 

(fig. 18H).

The shifts in nitrogen speciation are 

accompanied by an initial decrease in dissolvedmanganese (also iron) concentrations as reclaimed 

water percolates beneath the research basin; this 

decrease is followed by an increase as recharge 

continues through day 17, and by further increases as 

the research basin empties and water beneath the 

research basin stagnates (fig. 19). Dissolved-oxygen 

concentrations vary inversely with manganese and 

decline to near the detection limit of about 0.4 mg/L 

after recharge is stopped (fig. 20). However, as shown 

in figure 19, manganese concentrations remained high, 

in excess of 1,000 μg/L at the piezometers beneath the 

clay lens (PR8 and PR10) throughout the recharge 

experiment, confirming (as do chloride and other 

chemical data) that the clay lens represents a barrier to 

measurable downward percolation during recharge at 

the research basin.

Dissolved-iron and dissolved-manganese 

concentrations usually are low in neutral and alkaline 

solutions unless oxygen is absent because both 

elements are very insoluble in their higher oxidation 

states. Manganese can be reduced, and thereby reach 

high dissolved concentrations, at a higher redox 

potential (less reducing environment) than can iron. 

Thermodynamic calculations for a few samples from 

beneath the research basin using WATEQ4F (Plummer 

and others, 1984) and based on the nitrogen redox 

couples (nitrate/nitrite and nitrate/ammonia) and on 

manganese concentrations yield Eh values of about 350 

to 450 millivolts. In fact, the manganese redox couple 

is close to that for nitrate reduction. The high levels of 

manganese, very low levels of oxygen, and apparent 

removal of nitrogen all suggest that microbial 

denitrification is occurring beneath the research basin.

Further evidence of denitrification comes from 

nitrogen-isotope ratios measured for a few samples 

collected before (April 4, 1994), during (April 6), and 

after (June 1) filling of the research basin. 

Denitrification results in a decrease in nitrate 

concentrations and typically is accompanied by 

enrichment in nitrogen-15 in the remaining nitrate 

(Schroeder and others, 1993, and references therein). 

Such enrichment is observed in this study for sample 

pairs from 1-foot intervals between 5 and 10 ft below 

the research-basin floor (table 9). As reclaimed water 

replaces and mixes with existing ground water, 

nitrogen concentrations increase, and the δ15N 

decreases from about 35 o/oo to about 10 o/oo, a value 

typical of domestic and municipal wastewater. 

Following cessation of recharge, denitrification occurs 

and δ15N increases again to about 60 o/oo at day 58, 

long after recharge has ceased. The enrichment in 

nitrogen-15 can be expressed in terms of an isotopeseparation (fractionation) factor, ε, from the equation

δ15Nf = δ15Ni + εLn[NO3

-

]f / [NO3

-

]i,

where 

the subscripts “i” and “f” refer to initial and final 

isotope-ratio and nitrate-concentration data. 
Chapter 5: Changes in Common Chemical Constituents During Recharge 39

10

8

6

4

2

0246 8 10 12 14 16 18 20

0

TIME SINCE RECHARGE BEGAN, IN DAYS

CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

NH4-N (PR12)

NO3-N (PR12)

NH4-N (MLS5)

NO3-N (MLS5)

Figure 17. Changes in ammonia (NH4-N) and nitrate (NO3-N) concentrations in recycled water in the research basin (PR12) and from 5 feet beneath the 

floor of the research basin, Montebello Forebay, Los Angeles County, California, during the second recharge experiment that began in April 1994.
40 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

02 4 6 8 10 16 12 14

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

A -— Before recharge

Figure 18. Changes in concentration and distribution of nitrogen species in the research basin, Montebello Forebay, Los Angeles County, California, as 

the research basin is filled with recycled water for 17 days: A, before recharge; B, 0.5 day after recharge began; C, 1 day after recharge began; D, 2 days; E, 

3 days; F, 4 days; G, 17 days (last day of recharge); H, 58 days (41 days after recharge discontinued). NO3, nitrate; NO2, nitrite; NH4, ammonia. 
Chapter 5: Changes in Common Chemical Constituents During Recharge 41

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

30

B — 0.5 day after recharge began

02 4 6 8 10 16 12 14

Figure 18.—Continued.
42 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

30

NO -N 3

NO -N 2

NH -N 4

C — 1 day after recharge began

02 4 6 8 10 16 12 14

Figue 18.—Continued.
Chapter 5: Changes in Common Chemical Constituents During Recharge 43

30

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

02 4 6 8 10 16 12 14

D — 2 days after recharge began

Figure 18.—Continued.
44 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

02 4 6 8 10 16 12 14

30

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

E — 3 days after recharge began

Figure 18.—Continued.
Chapter 5: Changes in Common Chemical Constituents During Recharge 45

02 4 6 8 10 16 12 14

F — 4 days after recharge began

30

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

Figure 18.—Continued.
46 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

30

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

NO3

NO2

NH4

246 8 10 16 12 14

G — 17 days after recharge began (last day of recharge)

Figure 18.—Continued.
Chapter 5: Changes in Common Chemical Constituents During Recharge 47

30

CUMULATIVE CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

5

0

10

15

20

25

NO3

NO2

NH4

H — 58 days after recharge began (41 days after recharge discontinued)

02 4 6 8 10 16 12 14

Figure 18.—Continued.
48 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

TIME SINCE RECHARGE STARTED, IN DAYS

0 10 20 30 40 50 60

CONCENTRATION OF DISSOLVED-MANGANESE, IN MICROGRAMS PER LITER

1

10

100

1,000

MLS5

MLS10

PR8

PR9

PR10

PR11

Figure 19. Changes in dissolved-manganese concentration beneath the research basin, Montebello Forebay, Los Angeles County, California, during 

recharge with recycled water (MLS, multilevel sampler at indicated depths in feet; piezometers above, PR9 and PR11, and below, PR8 and PR10, the clay 

lens).
Chapter 5: Changes in Common Chemical Constituents During Recharge 49

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

30

DISSOLVED OXYGEN CONCENTRATION,

IN MILLIGRAMS PER LITER

024 6 8 10

DAY 1

DAY 2

DAY 58

PR12 (Research Basin)

Figure 20. Changes in dissolved-oxygen concentration beneath the research basin, Montebello Forebay, Los Angeles County, California, at selected times 

during the recharge experiment.
50 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

In this case, the initial values are those obtained 

during the second day of recharge on April 6, and final 

values are those obtained long after recharge ceased on 

June 1. The calculation yields an isotope-separation 

factor (ε) of −23.3 ± 1.6 o/oo, a value close to the more 

negative (larger magnitude) end of the range from −30 

to −5 o/oo reported in the literature for fractionation 

during denitrification in a variety of ground-water 

environments (Schroeder and others, 1993, and 

references therein).

Although analytical data do not exist for initial 

conditions before April 4, a hypothetical value for ε

can be formally calculated by assuming that 

concentration and isotope data from April 6 are 

representative of “initial” values for earlier recharge. 

Note that this calculation yields a very similar value 

(−21.1 ± 2.4 o/oo), even though the initial conditions are 

actually some undetermined combination of input from 

the first recharge experiment in August 1993, natural 

recharge during the intervening winter, and regional 

spreading operations at the adjacent San Gabriel River 

Coastal Spreading Grounds. This result, as well as the 

increase in manganese concentration and relative 

enrichment in reduced nitrogen species, by the last day 

that effluent was added to the research basin on April 

21, indicates that the redox environment for 

denitrification during recharge itself is present 

throughout recharge, particularly during the latter 

period of recharge, and not only during the interval 

between recharge events. In addition, two high values 

for δ15N (>41 o/oo) in the piezometer below the clay 

lens (PR8), which is unaffected by recharge 

experiments in the research basin, argue strongly that 

denitrification may have a larger areal extent than just 

at the research basin itself.

Other Possible Mechanisms for Nitrogen Removal

Other possible mechanisms for reduction of 

aqueous nitrogen (reduced species only) concentration 

include: 

1. Volatilization of ammonia from the water in 

the research basin or from the moist soil surface as the 

floor of the research basin dries,

2. Cation exchange of ammonia on soil beneath 

the research basin, and 

3. Sorption or incorporation within the organicrich, fine-grained layer that accumulates in a thin 

infiltration zone on the floor of the research basin. 

Although it would be difficult to quantify the 

importance of each of these mechanisms, some 

theoretical considerations described herein can yield 

plausible arguments for or against them.

Table 9. Nitrogen-isotope data for nitrate in water below research basin, Montebello Forebay, Los Angeles County, California, during April–June 1994 

recharge experiment

[Refer to text for description of “formal” methodology to calculate fractionation between days 0 and 2; mg/L, milligrams per liter; per mil, parts per thousand; 

MLS, multilevel sampler; —, no data ]

a

Data for PR8 not used in calculation.

Sample

identifier

Nitrate-N

(mg/L)

N-15

(per mil)

Isotope 

separation factor

(per mil)

Day 0 Day 2 Day 58 Day 0 Day 2 Day 58 Day 0/2 Day 2/58

MLS10 2.38 8.95 0.66 40.4 7.6 65.3 −24.76 −22.13

MLS9 2.47 8.53 .58 39.3 8.1 66.7 −25.17 −21.80

MLS8 1.66 6.47 1.07 41.7 9.5 54.3 −23.67 −24.90

MLS7 2.8 7.21 .53 31.5 10.2 60.9 −22.52 −19.42

MLS6 2.97 7.81 .89 31.5 9 52.6 −23.27 −20.07

MLS5 2.05 7.51 .77 37.8 10.9 52.6 −20.72 −18.31

PR8 1.48 1.49 1.4 41.2 41.8 — — —

Average 9.22a −23.35 −21.11

Standard deviation 1.25a 1.62 2.35
Chapter 5: Changes in Common Chemical Constituents During Recharge 51

Volatilization

The direction of ammonia transport across an 

air/water interface is determined by relative 

concentrations of the (un-ionized) gas in the water and 

atmosphere and the rate of exchange is dependent on 

such environmental factors as windspeed. The pKa

(pH at which the ammonium ion and un-ionized 

ammonia are present in equal concentrations) of the 

ammonium ion is 9.3 in dilute solution and varies with 

salinity and temperature. For environmental conditions 

at the study site, equilibrium geochemical calculations 

indicate that about 10 percent of total dissolved 

ammonia plus ammonium is in the un-ionized 

ammonia form (R. Seiler, USGS, written commun., 

2002) that is susceptible to loss by volatilization. 

However, analysis of air samples collected immediately 

above the water surface in the research basin did not 

find ammonia concentrations to be higher than outside 

the basin (T.F. Rees, USGS, oral commun., 1996), 

although differentiation based on these analyses is poor 

due to high ambient (background) ammonia 

concentrations in the region. Loss by volatilization of 

ammonia probably is negligible, although a definitive 

conclusion is not possible.

 Ion Exchange

Certain clay minerals have the ability to 

exchange cations through ion exchange in aqueous 

solutions with which they are in contact. Cationexchange capacity, which is an indication of this 

ability, was measured by equilibration of soil from 

selected depths beneath the research basin with a 1N 

ammonium acetate solution. The results, on a dry 

mineral-weight basis, average about 3 meq/100 g 

(milliequivalents per 100 grams of soil) between 

0.5 and 3 ft below the research basin and increase to 

about 5 meq/100 g in the more clay-rich infiltration 

zone extending from the research-basin floor to a depth 

of 0.5 ft (Anders, 1997). Converting the cationexchange capacity of 3 meq/100 g to a pore-volume 

solution basis by using a mineral-weight density of 2.6 

g/cm3 and porosity of 0.24 yields an average value of 

about 250 meq/L for soil more than 0.5 ft beneath the 

research basin. Ammonia present in the research basin 

during the first few days of the second recharge 

experiment averaged 4.74 mg/L as nitrogen, which 

equates to 0.34 meq/L. Hence, the basin's soil has the 

capacity to remove, by cation exchange, more than 

1,000 void-space volumes of recycled water if all of the 

major cations are exchanged for the ammonium ion. 

Because about 50 ft, equivalent to 12.5 acre-ft, of 

recycled water was delivered to the research basin 

during the second experiment, percolation through less 

than an inch of soil would be sufficient to remove all 

the ammonium ion if all the exchangeable sites were 

replaced with ammonium! 

These results seem to indicate a major capacity 

for ammonium removal by cation exchange, but there 

are some limitations to this conclusion. Ion exchange is 

a competitive process among ammonium and the other 

major cations, and thus only a small fraction of the total 

capacity actually is available for ammonium-ion 

exchange. Reequilibration between the soil and water 

takes place each time the relative cation concentrations 

change in the soil moisture that is in contact with the 

ion-exchangeable clays. Recharge with oxygenated 

water probably leads initially to removal of any 

ammonium from the soil and its subsequent microbial 

oxidation to nitrate. Then the less oxic conditions that 

prevail during the latter stages of recharge, and 

especially during stagnation after recharge is 

discontinued, reverse the equilibrium to favor exchange 

of ammonium back onto the soil. As long as any 

oxygen at all is present in the subsurface, it would seem 

that this cyclic process could continue indefinitely 

without any long-term increase in exchangeable 

ammonium in the soil.

The behavior of three minor-element cations, 

barium (Ba2+), strontium (Sr2+), and lithium (Li+), 

where concentrations are at least 100 times less than 

the concentration of ammonium on an equivalents 

basis, can be used to investigate the ion-exchange 

process—and thereby infer the effect this process may 

have on ammonium (NH4

+), for which susceptibility to 

biological transformation confounds interpretation. To 

interpret the data for all three cations, it is helpful to 

recall that divalent ions are bound more tightly to clays 

than are monovalent ions (Berner, 1971), hence the 

pattern for Li+ is expected to more closely mimic 

NH4

+. The computer program WATEQ4F (Plummer 

and others, 1984) was used to confirm undersaturation 

with respect to formation of sulfate and carbonate 

minerals, except for barium for which the ion-activity 

product slightly exceeds the solubility product of barite 

(barium sulfate).
52 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

For all three minor ions, there was no temporal 

trend in concentration below the clay lens throughout 

the 17-day recharge experiment in April 1994 (data in 

appendix 3), as would be expected if percolating water 

does not move beneath the clay lens. However, trends 

are discernible between the research-basin floor and 

the top of the clay lens (fig. 21). For barium, 

concentration in the research basin (PR12) is much 

less, at 41 μg/L (0.60 μeq/L), than is concentration in 

the soil moisture before recharge, at about 150 μg/L. 

There is little, if any, decrease in concentration during 

recharge, even in a band of somewhat higher 

(>200 μg/L) concentrations between 15 and 20 ft 

beneath the research-basin floor. This result implies 

that sufficient barium is available to desorb from the 

soil and maintain high aqueous concentrations during 

recharge, despite replacement of water in the pore 

spaces as many as several (but less than10) times over. 

For strontium, concentrations are about the same in the 

research basin (519 μg/L, or 11.8 μeq/L) and in soil 

moisture to a depth of 10 ft beneath the research basin, 

and therefore do not change during recharge. Between 

15 and 25 ft, concentrations range from 800 to

900 μg/L before recharge, and do not decrease during 

the first 3 days of recharge. However, there is a 

noticeable decrease of about 230 μg/L (about 5 μeq/L) 

across this deeper zone between the 3rd and 17th day 

of recharge. Lithium concentrations of about 17 μg/L 

(2.4 μeq/L) in the research basin are about double those 

below the research basin before recharge. After the first 

4 days of recharge, lithium concentrations increase 

about 3 μg/L (0.4 μeq/L) to a depth of 20 ft. No further 

increase occurs over the remaining 13 days of recharge, 

despite the fact that concentrations still are about 5 

μg/L less than in the recycled water from the research 

basins.

The patterns described above strongly suggest 

kinetic limitations to the establishment of complete 

ion-exchange equilibrium as recycled water percolates 

through the soil column. As with lithium, the effects of 

ion exchange for ammonium are likely to manifest 

themselves to a depth extending at least several feet 

beneath the research-basin floor (the entire percolation 

zone), and perhaps almost to the clay lens itself, rather 

than be confined to the top few inches (the infiltration 

zone).

Sorption

The final process considered for organic carbon 

and nitrogen removal is sorption, or incorporation with 

soil on the floor of, and possibly immediately below, 

the research basin itself. Because the concentration of 

organic matter, and trace constituents as well, is 

typically about three orders of magnitude less in water 

than in the solid phase with which the water is in 

contact, even complete removal from the percolating 

water is unlikely to be discernible solely from soil 

analyses, unless such removal is confined to the top 

few inches beneath the research-basin floor, given the 

volume delivered and concentrations in the recycled 

water. Removal within such a thin infiltration zone is a 

likely possibility. However, as with ion-exchange, the 

long-term implications are less certain during repeated 

cycles of recharge and desiccation because some of this 

organic carbon and nitrogen undoubtedly is 

mineralized between successive recharge events.
Chapter 5: Changes in Common Chemical Constituents During Recharge 53

DISSOLVED CONCENTRATION, IN MICROGRAMS PER LITER

0

5

10

15

20

25

30

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

1 10 100 1,000

Day 0 (April 4, 1994)

Day 3 (April 7, 1994)

Day 17 (April 21, 1994)

Barium (Ba)

Strontium (Sr)

Lithium (Li)

PR12 average

EXPLANATION

Figure 21. Progress toward reequilibration of dissolved barium (Ba), strontium (Sr), and lithium (Li) beneath the research basin, Montebello Forebay, Los 

Angeles County, California, on the 3rd (April 7, 1994) and 17th (April 21) days of recharge with recycled water.
54 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

As was done for ion exchange, a surrogate, 

orthophosphate (PO4) in this case, was chosen to 

illustrate possible effects of sorption during recharge. 

Phosphate was calculated (Plummer and others, 1984) 

to be oversaturated with respect to apatite minerals 

(especially fluorapatite), but formation of these 

minerals is slow. Phosphate is readily sorbed onto 

particle surfaces, including organic and hydrous 

ferromanganese oxide coatings that are commonly 

present in soils, and this is more likely to control 

concentrations over the short time of a recharge 

experiment. Phosphate as phosphorus (PO4-P) 

concentration decreased from about 2 mg/L in the 

research basin to a “near-equilibrium” (steady-state) 

concentration of about 1.2 mg/L to a depth of 15 ft 

beneath the basin as recharge continued (fig. 22). The 

concentration at 4 ft was already 1.2 mg/L before 

recharge, and remained at that level throughout 

recharge. Concentrations below 4 ft also were elevated, 

although they were less than 1.2 mg/L before recharge 

began, reflecting the influence of prior recharge to 

either the research basin or the adjacent spreading 

grounds. The pattern described suggests saturation of 

sorption sites and implies that some removal occurs, 

perhaps through incorporation as insoluble 

organophosphorous compounds, on or just beneath the 

basin floor. If so, the decrease is similar in magnitude 

to that observed for organic carbon. However, unlike 

organic carbon, for which mineralization can lead to 

removal (as carbon dioxide or alkalinity), 

mineralization of organophosphorous in the subsurface 

yields inorganic phosphate, which can remain behind 

to establish the depth-related profile observed. It would 

seem that eventually this pattern of decreasing 

phosphate concentration with increasing depth will 

disappear as additional recharge experiments are done 

unless phosphate is removed through some slow 

precipitation (mineral formation) process. The fact that 

the profile for dissolved organic carbon in figure 15 is 

much less steep than is the profile for orthophosphate 

in figure 22 indicates that sorptive removal, once the 

recycled water has penetrated more than a few feet 

beneath the basin floor, is comparatively less important 

for organic carbon.

Relative Importance of Oxygen and Nitrate as 

Electron Acceptors

Microbial oxidation of organic carbon can be 

represented by two idealized (for carbohydrates) 

reactions:

CH2O + O2 → CO2 + H2O

and

4NO3

-

 + 5(CH2O) → 2N2 + CO2 + 3H2O + 4HCO3

-

,

representing oxygen and nitrate (denitrification) as 

electron acceptors, respectively. On the basis of the 

stoichiometry for these model reactions, the mass ratio 

of carbon oxidation to oxidant required is 0.375 mg 

C/mg O and 1.07 mg C/mg N. These values could be 

used to quantify the relative importance of each process 

to organic carbon removal during percolation through 

the soil column if all chemical transformations and 

physical processes were known with certainty. They are 

not, and therefore the best that can be done is a 

plausible relative ranking of importance.
Chapter 5: Changes in Common Chemical Constituents During Recharge 55

Day 0 (April 4, 1994)

Day 3 (April 7, 1994)

Day 17 (April 21, 1994)

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

5

10

15

20

25

30

DISSOLVED-PHOSPHATE CONCENTRATION,

IN MILLIGRAMS PER LITER AS PHOSPHORUS

0.01 0.1 1 10

PR12 average

Figure 22. Removal of orthophosphate from recycled water beneath the research basin, Montebello Forebay, Los Angeles County, California, on the 3rd 

(April 7, 1994) and 17th (April 21) days of recharge.
56 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

As discussed in the “Nitrogen” section in this 

chapter, by the 17th day of the second recharge 

experiment, total nitrogen had declined in the 

multilevel sampler by about 60 percent, representing a 

reduction of about 7 mg/L. The decline in organic 

carbon was about 35 percent after 2 days of recharge, 

representing a reduction of a little more than 3 mg/L. 

The average highest dissolved-oxygen concentration 

(fig. 20 and data in appendix 3), attained during the 

first few days of recharge, in the multilevel sampler 

was 5.0 mg/L (range from 2.4 mg/L at the 20-foot 

depth to 6.6 mg/L at the 10-foot depth). Even if this 

oxygen were entirely consumed by oxidation of only 

dissolved organic carbon, to the exclusion of all other 

reduced constituents (especially nitrogen), it would 

yield a removal of slightly less than 2 mg/L in the 

dissolved organic carbon. This would seem to imply 

that denitrification is about an equally important 

mechanism for removal of organic carbon. The fact that 

the average highest nitrate plus nitrite (as nitrogen) 

concentration, also attained during the first few days of 

recharge, in the multilevel sampler was 8.5 mg/L 

(range from 6.3 to 9.7 mg/L) certainly indicates that 

there is more than enough oxidized nitrogen available 

to effect a further reduction in dissolved organic 

carbon. In fact, the question for which a satisfactory 

answer is not available is why does there appear to be 

less organic carbon than required to explain the 

observed decrease in nitrogen of about 7 mg/L if 

removal is entirely from heterotrophic (carbon as 

electron donor) denitrification. The implication is that a 

substantial part of the apparent removal represents 

temporary storage of reduced nitrogen on ionexchangeable clays or in sorbed organic nitrogen and 

(or) reduction by electron donors other than just 

organic carbon.

An important caution should be noted in these 

conclusions. These mass-balance calculations are 

based on the assumption that the subsurface system is 

closed to the atmosphere during recharge. Although 

this may be a valid assumption when little or no 

unsaturated zone exists, as in the first two recharge 

experiments, recharge through a thick unsaturated zone 

could induce incorporation of additional atmospheric 

oxygen into the percolating water, especially during 

early stages of recharge before water has a chance to 

completely fill void (pore) spaces in the soil.

And another limitation, which may have an even 

more important implication for the long-term and net 

changes in ground water chemical composition at 

downgradient production wells, is the extent to which 

removal of aqueous constituents is from actual 

degradation and from permanent incorporation with the 

solid phase rather than simply temporary storage on the 

soil.
Chapter 6: Hierarchal Approach to Organic Matter Characterization 57

PART II

CHAPTER 6: HIERARCHAL APPROACH TO 

ORGANIC MATTER CHARACTERIZATION

By Jerry A. Leenheer and Larry B. Barber

The characterization of dissolved organic matter 

(DOM) is a complex endeavor requiring a hierarchal 

analytical approach (Leenheer and Huffman, 1976; 

Barber, 1992) that measures, among other things: (1) 

total, particulate, colloidal, and dissolved carbon, (2) 

operationally defined dissolved organic carbon (DOC) 

fractions, (3) molecular-weight characteristics, (4) 

compound classes and functional-group characteristics, 

and (5) specific organic compounds. A hierarchal 

approach was designed to comprehensively 

characterize organic matter in reclaimed water that 

might be transported into the subsurface environment 

during artificial recharge. Particulate organic matter 

was removed from reclaimed-water and ground-water 

samples by glass-fiber filtration in the field through 

25-μm and 0.3-μm cartridge filters in series (Leenheer 

and Noyes, 1984), and colloids were then isolated from 

the filtrate by tangential flow ultrafiltration using 

regenerated cellulose membranes with 0.005-μm pore 

size (Leenheer and others, 1989; Rostad and others, 

1998). Colloids recovered from the membranes were 

characterized separately from the dissolved organic 

matter in the membrane permeate.

The DOC was characterized at various hierarchal 

levels (fig. 23). The classification basis and the 

percentage that can be characterized at each of the 

levels are shown in figure 23. At the first three levels of 

this hierarchy, all of the carbon in certain samples was 

characterized by DOC fractionation analyses. Analyses 

of compound classes (level 4) required isolation of the 

DOC fractions for spectra characterizations by 

13C-nuclear magnetic resonance (13C-NMR) 

spectrometry, infrared (IR) spectrometry, and 

ultraviolet-visible (UV/VIS) spectrometry. The greatest 

potential to obtain new research information on DOC 

characterization is at level 4 owing to recent 

improvements in fraction isolation and spectral 

characterization techniques. Lastly, certain specific 

compounds that are indicative of sewage wastewater 

and disinfection by-products were analyzed by gas 

chromatography-mass spectrometry (GC/MS). The 

following chapters of this report are presented in order 

of increasing molecular specificity as determined by 

the hierarchal analytical approach. The chemical 

structures of selected organic constituents discussed are 

shown in figure 24.
58 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Specificity

Classification

Basis

Dissolved organic carbon

Hydrophobic

organic carbon

Hydrophilic

organic carbon

Acids Neutrals Bases Acids Neutrals Bases

Anionic

detergents

Chlorinated

hydrocarbon

insecticides

Polynuclear

amines

Polyuronic

acids

PolysaccharidesAmino

sugars

Concentration

Polarity

Acid-base

character

Compound

classes

Specific

compounds

Organic and

inorganic

complexes

Level

1

2

3

4

5

6

Characterization

potential

100%

100%

100%

50–

100%

1–10%

<1%

Figure 23. Hierarchal classification of dissolved organic carbon (<, less than).
Chapter 6: Hierarchal Approach to Organic Matter Characterization 59

1. 9.

10.

11.

12.

13.

2.

3.

4.

5.

6.

7.

8.

R6

R1

R1

R1

R4

R2

R2

R5 R3

SO3

-

SO3

-

SO3

-

R1

R4 R2

R5

R3

SO3H

R1

R4 R2

R5

R3

Aromatic carbons

Dialkyltetraline sulfonate (DATS)

Caffeine

Amide carbons

Alklyphenol polyethoxylate (APEO)

Acid R-COOH

Alcohol R-OH

Alkyl benzene sulfonate

Alklyphenol polyethoxy carboxylate (APEC)

Aetal, Hemiacetal Carbons Aromatic sulfonate

Aromatic sulfonic acid

Carbohydrate carbons

(CH2CH2O) C9H18 O n CH2CH2

O

O

C N

N

O

O

O

O O

O

O

N

N N

OH

(CH2CH2O)n CH2

CH3

CH3

CH3

CH2OH

CH2

OH

OH

OH

OH

OH

O

O O

C

C

O

O

CH2OH

CH2

OH

OH

OH

OH

OH

C9H18 O O C -

Figure 24. Chemical structure of selected organic compounds and functional groups.
60 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

Nonylphenol 1-3-ethoxylate

Nonylphenol 1-ethoxylate carboxylic acid

Olefinic carbons R1—C=C—R2

Peptide linkage

Pyrimidine

Quarternary carbons

Sulfophenyl carboxylate (SPC)

Methyl carbons -CH3

Methine carbons of amino acids

Methylene carbons —CH2-—

CH2CH3 CH2CH3

CH2CH3

C9H18

C9H18

OO O

OH

CH2CH3

CH2

CH2CH3

CH2

N

N+

R1

O

O

R3

R2

R

H

C COOH

R4

NH2

Ether R1-O-R2

Ether R1COOR2

Direct Blue Dye (Erioglaucine)

Linear alkylbenzene sulfonate (LAS)

Ketone/Quinone

O COOH CH2CH3

R1 C R2

R4 R2

R1

R3

OO

C

N

O H

N

N

C

SO3

-

SO3

-

SO3

-

SO3

-

SO3

-

Figure 24.—Continued.
Chapter 7: Isolation and Characterization of Colloids 61

CHAPTER 7: ISOLATION AND 

CHARACTERIZATION OF COLLOIDS

By Kevin A. Thorn, Colleen E. Rostad, and

Ted I. Noyes

Among particles present in the environment, 

colloids are smaller in diameter than the particulate 

phase and larger than the humic phase. Although the 

transition from particulate to colloid to humic phases 

seems to involve a gradual decrease in size and 

concurrent increase in organic carbon content, the 

composition of their organic carbon may be distinctly 

different. The organic composition of ground-water 

colloids is unknown. The nature of this mobile phase in 

the aquifer is of concern in the recharge of aquifers 

with sewage effluent (recycled water). In this study, the 

colloid phase was characterized by elemental 

composition and multinuclear (carbon-13, nitrogen-15, 

and phosphorus-31) nuclear magnetic resonance 

(NMR) spectrometry.

Sampling and Methods

Colloid Isolation Procedures

During the April 1994 recharge experiment, the 

colloid phase was isolated from water samples 

collected from PR13 (wastewater effluent), MLS4 and 

MLS7 (multilevel sampler at depths of 4 and 7 ft 

beneath the research-basin floor), and well PR9 (25 ft 

beneath the research-basin floor). During the 

September 1994 recharge experiment, the colloid phase 

was isolated from water samples from PR12 (research 

basin) and PR9. Water samples were pumped onsite 

through Balston DH (25-μm) and AH (0.3-μm) glassfiber prefilters to remove the larger particulate matter. 

Colloids were isolated from the prefiltered solution by 

ultrafiltration using a Series L Dorr-Oliver tangentialflow ultrafiltration system (Amicon Div. W.R. Grace, 

Beverly, Massachusetts), which had been modified by 

replacing all plumbing with Teflon pipe, and using an 

air-driven, double-diaphragm Teflon-bellows pump for 

solution circulation (Rostad, 1996; Rostad and others, 

1998). Colloids on the ultrafilter membranes were 

placed in PFA Teflon bags, and resuspended by gently 

massaging the membrane from the outside of the 

Teflon bag. Colloids in aqueous suspension were then 

transferred to a 2-L Teflon bottle, preserved with two 

drops of chloroform, refrigerated, and transported on 

ice to the laboratory. Four mL of this liquid colloid 

concentrate was transferred to a glass vial and 

refrigerated for future analyses. The retentates from the 

ultrafilters, designated as the colloid phase, were 

freeze-dried. Advantages of these particle-isolation 

techniques include minimal introduction of sampling 

artifacts by the isolation equipment, and the ease of 

sample retrieval. A colloid sample similarly isolated 

from Thoreau’s Bog, a pristine bog in Concord, 

Massachusetts, was provided by Dr. James Ranville, 

Colorado School of Mines, as a commonly used 

standard for comparison to the colloids isolated from 

the recharge basin.

Analytical Methods

The colloid samples were characterized by 

elemental analysis and by multinuclear

 (13C, 15N, and 31P) solid-state cross 

polarization/magic angle spinning (CP/MAS) nuclear 

magnetic resonance (NMR) spectrometry. Elemental 

analyses were performed by Huffmann Laboratories, 

Golden, Colorado (Huffman and Stuber, 1985). Solidstate CP/MAS NMR spectra were recorded on a 

Chemagnetics CMX-200 NMR spectrometer at carbon, 

nitrogen, and phosphorus resonant frequencies of 50.3, 

20.3, and 80.9 megahertz (MHz), respectively, using a 

7.5-mm ceramic probe (zirconium pencil rotors). 

Acquisition parameters for the 13C NMR spectra 

included a 30,000 Hz spectral window, 17.051-ms 

acquisition time, 2.0-ms contact time, 1.0-s pulse delay, 

and spinning rate of 5 kHz. Spectra were referenced to 

hexamethylbenzene. Acquisition parameters for the 

15N NMR spectra included a 30,000 Hz spectral 

window, 17.051-ms acquisition time, 2.0-ms contact 

time, 1.0-s pulse delay, and spinning rate of 3.5 kHz. 

Chemical shifts were referenced to glycine, taken as 

32.6 parts per million (ppm). Acquisition parameters 

for the 31P NMR spectra included a 30,000 Hz spectral 

window, 34.1-ms acquisition time, 2.0-ms contact time, 

2.0-s pulse delay, and spinning rate of 3.5 kHz. 

Chemical shifts were referenced to ammonium 

dihydrogen phosphate, taken as 0.81 ppm.
62 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Results and Discussion

Colloid Concentration and Changes in Elemental Composition

The total amounts of colloids and colloidal 

organic carbon content, elemental analyses on 

moisture-free basis, elemental analyses on moistureand ash-free basis, and elemental mass-ratios during 

recharge experiments are given in tables 10–13, 

respectively. Comparison with data elsewhere in this 

report shows that colloidal organic carbon constitutes 

about 10 to 20 percent of the total (or dissolved) 

organic carbon; the percentage is highest in recycled 

water and lowest in percolating water beneath the 

research basin (table 11). For the April 1994 

experiment, the concentration of colloid isolated from 

MLS4 (4 ft below the floor of the research basin) is 

approximately one-half the concentration isolated from 

the effluent (PR13). These data indicate that a 

significant proportion of the colloidal material is 

filtered out as the water percolates through sediments 

beneath the research basin. Likewise, data in table 10

for the September 1994 experiment indicate that a 

significant proportion of the colloidal material is 

filtered out in the soil beneath the research basin; the 

concentration of colloid isolated from PR9 (25 ft 

beneath the basin) is approximately one-third that of 

the research basin (PR12).

In addition to removal, the composition of the 

colloids also changes with transport from the effluent 

(PR13) or research basin (PR12) through the sediment 

(PR9) during both the experiments (table 11). In the 

April experiment, the total-ash content of the recycledwater effluent increases from 37.2 percent to more than 

50 percent for samples from MLS4, MLS7, and PR9. 

In the September experiment, the increase in total-ash 

content (mineral matter that remains after combustion) 

is from 26.9 percent in the research basin itself to 43.8 

percent in PR9. Thus, the total-ash content of colloids 

increases and their organic content decreases as 

recycled water percolates beneath the research basin. 

This shift could be due to preferential filtration during 

percolation, sloughing of mineral matter from the soil, 

and (or) (most likely) organic decomposition.

Organic carbon content of colloids ranged from 

5.5 percent at PR9 in April 1994 to 27.2 percent at 

PR12 in September 1994 (table 11). By comparison, 

the organic content of river-water colloids isolated with 

this same technique ranged from 6.9 to 26.23 percent in 

summer, 5.02 to 30.85 percent in autumn, and 4.59 to 

27.06 percent in spring (Rostad, 1996; Rostad and 

others, 1994). For the river-water colloids, seasonal 

averages were 16.46 percent in summer, 16.09 percent 

in autumn and 12.99 percent in spring (Rostad, 1996; 

Rostad and others, 1994). For the two recharge 

experiments in this study, average organic carbon 

content was higher, 25 percent, in recycled water and 

lower, 9 percent, in water beneath the research basin. 

For the most part, nitrogen and organic carbon 

content of the colloids analyzed for this study are 

positively correlated—as also is the case for river 

colloids. Nitrogen content of colloids ranged from 1.6 

to 4.3 percent and, as with organic carbon, is somewhat 

higher in recycled water than in soil water beneath the 

research basin. The range from 1.6 to 2.6 percent 

beneath the research basin is about the same as values 

reported for river colloids, which averaged 2.19 percent 

in summer, 1.79 percent in autumn, and 1.54 percent 

during spring runoff, with an overall average of 1.8 

percent (Rostad, 1996; Rostad and others, 1998). 

The H/C, O/C, and N/C elemental mass ratios in 

table 13 indicate that the organic matter associated with 

the colloids is composed primarily of the undegraded 

biochemical constituents of bacteria or algae, and not 

of humic substances. The range of H/C values for the 

colloids, 0.14–0.33, is much less then the range of 

0.80–1.50 reported for soil and aquatic fulvic and 

humic acids (Steelink, 1985). The range of O/C values 

for the colloids, 1.2–5.6, also differs from the range of 

0.28–0.74 reported for soil and aquatic fulvic and 

humic acids. Finally, the range of N/C values for the 

colloids, 0.15–0.29, is higher than the range of 

0.01–0.09 reported for the humic substances. The 

colloids are enriched in nitrogen and oxygen and 

depleted in hydrogen in comparison with fulvic and 

humic acids, as would be expected if they were 

composed of bacterial, fungal, or algal matter.
Chapter 7: Isolation and Characterization of Colloids 63

Table 10. Amounts of colloid isolated from the research basin, Montebello Forebay, Los Angeles County, California, during recharge experiments

[L, liter; g, gram; mg/L, milligrams per liter; mg C/L, milligrams carbon per liter]

Sample 

identifier Date

Volume of

water sampled

(L)

Yield of

colloid

(g)

Concentration

of colloid

(mg/L)

Colloidal carbon

concentration

(mg C/L)

MLS7 04-06-94 220 1.0 4.5 0.5

MLS4 04-05-94 220 1.2 5.5 .5

PR9 04-07-94 220 .9 4.1 .3

PR13 (effluent) 04-06-94 110 1.2 10.9 2.5

PR9 09-22-94 400 .7 1.7 .3

PR12 (pond) 09-19-94 240 1.3 5.2 1.5 

Table 11. Elemental analyses, on moisture-free basis, of colloids from the research basin, Montebello Forebay, Los Angeles County, California

[Concentrations in percent on moisture-free basis; C, carbon; H, hydrogen; O, oxygen; N, nitrogen; S, sulfur; P, phosphorus]

Sample 

identifier Date C

(total)

C

(carbonate)

C

(organic) H O N S P Ash 

PR13 04-94 23.3 1.40 21.9 3.2 29.5 3.2 4.1 0.6 37.2

MLS4 04-94 9.0 1.62 7.4 1.8 25.1 1.9 4.6 .2 57.4

MLS7 04-94 10.8 2.10 8.7 2.0 28.6 1.9 5.6 .2 50.9

PR9 04-94 7.9 2.39 5.51 1.8 30.9 1.6 6.4 .1 51.4

PR12 09-94 28.2 .98 27.2 4.3 32.5 4.3 3.0 .8 26.9

PR9 09-94 14.9 1.80 13.1 2.5 30.9 2.6 5.0 .3 43.8

Table 12. Elemental analyses of colloids, on moisture- and ash-free basis, from the research basin, Montebello Forebay, Los Angeles County, California

[These values are calculated on a mineral-free basis from values in table 11; concentrations in percent on moisture- and ash-free basis; C, carbon; H, hydrogen; 

O, oxygen; N, nitrogen; S, sulfur; P, phosphorus]

Sample identifier Date C H O N S P

PR13 04-94 34.9 5.1 47.0 5.1 6.5 1.0

MLS4 04-94 17.4 4.2 58.9 4.5 10.8 .5

MLS7 04-94 17.7 4.1 58.2 3.9 11.4 .4

PR9 04-94 11.3 3.7 63.6 3.3 13.2 .2

PR12 09-94 37.2 5.9 44.5 5.9 4.1 1.1

PR9 09-94 23.3 4.4 55.0 4.6 8.9 .5

Table 13. Selected elemental mass ratios in colloids from the research basin, Montebello Forebay, Los Angeles County, California

[C, carbon; H, hydrogen; O, oxygen; N, nitrogen]

Sample 

identifier Date H/C O/C N/C C/N

PR13 04-94 0.14 1.35 0.15 6.84

MLS4 04-94 .24 3.40 .26 3.88

MLS7 04-94 .23 3.29 .22 4.58

PR9 04-94 .33 5.61 .29 3.44

PR12 09-94 .16 1.19 .16 6.33

PR9 09-94 .19 2.36 .20 5.04
64 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Although the colloid phase approaches humic 

materials in organic carbon content, its organic carbon 

composition is distinctly different. The C/N ratios of 

the ground-water colloids ranged from 3.4 to 6.8, and 

averaged 5.0. The C/N ratio of 6.6 (average of PR12 

and PR13) in recycled water decreases to 4.2 in the 

subsurface (table 13). These colloid C/N ratios are 

much lower than those in various types of soils, humic 

materials, or plants (Rostad, 1996). They are even 

lower than the comparatively low C/N ratios of river 

colloids, which average about 8. Aquatic colloids 

commonly are compared to, equated with, or related to 

aquatic fulvic acids (Shinozuka and Nihei, 1994; 

Tombacz and Regdon, 1994), but their much higher 

C/N ratios indicate a substantial difference in organic 

material composition. The colloid C/N ratios in this 

study are more similar to those of biomass, such as 

bacteria (3–5), algae (5.6), and microbial cells (6) 

(Rostad, 1996; Rostad and others, 1998), indicating 

cellular material that has not yet undergone substantial 

diagenesis (degradation).

Nuclear Magnetic Resonance Spectrometry

The solid-state CP/MAS NMR spectra 

(figs. 25A–L) provide further evidence that the organic 

matter associated with the colloids is derived from the 

biochemical constituents of bacteria or algae. Several 

observations can be made on the spectra of colloids 

collected from the research basin (PR12) in September 

1994. Major peaks in the 13C CP/MAS spectrum 

(fig. 25E) occur at 24.4 ppm (methyl carbons), 

32.6 ppm (methylene carbons), 56.0 ppm (methine 

carbons of amino acids), 72.3 ppm (carbohydrate 

carbons), 102.7 ppm (anomeric carbons of 

carbohydrates), 131.1 ppm (aromatic carbons; for 

example, in aromatic side chains of amino acids) and 

175.2 ppm (carboxylic acid and amide carbons). The 

dipolar dephased 13C CP/MAS NMR spectrum (fig. 

25I) aids in the confirmation of these assignments. 

When a dipolar dephasing time of 40 μs is employed, 

almost all signal intensities from methine and 

methylene carbons are removed from the spectrum, 

whereas signals from quaternary and methyl carbons 

are retained. The disappearance of the peaks at 131.1, 

102.7, 72.3, and 56.0 ppm is consistent with the 

assignment of these as methine carbons, whereas the 

retention of the signals near 175.2 and 24.4 ppm is 

consistent with the assignments of these as quaternary 

and methyl carbons, respectively. The attenuation of 

the signal near 32.6 ppm is consistent with the 

assignment of these carbons as methylenes.

Comparison of the CP/MAS 13C NMR spectrum 

in the effluent (PR13) and the research basin (PR12) to 

the spectrum of the Thoreau’s Bog (a commonly-used 

standard for comparison) colloid provides a further 

indication that the organic matter of colloids in 

recycled wastewater is fundamentally different from 

humic material. The peaks in the spectra for this study 

(figs. 25A–F) are sharper and their resolution is closer 

to baseline than in the spectrum of the Thoreau’s Bog 

colloid (fig. 25J), which is composed predominantly of 

more structurally heterogeneous humic material. In 

addition, the ketone/quinone peak at 180 to 220 ppm in 

the Thoreau’s Bog spectrum that is characteristic of 

humic substances is absent in colloids from this study.

The solid state CP/MAS 15N NMR spectra of 

effluent (PR13) and recycled water in the research 

basin (PR12) have sharp secondary amide peaks 

(amino acid nitrogens involved in peptide linkages) at 

117–120 ppm (figs. 25G, H). The line-width and the 

relatively short acquisition time required to achieve the 

intensity of the signal are consistent with these 

nitrogens representing intact proteinaceous material.

The solid-state CP/MAS 31P NMR spectra of 

colloids in the research basin (PR12) and in percolating 

water 25 ft beneath the floor of the research basin 

(PR9) exhibit major peaks centered at approximately

−2.6 ppm (figs. 25K, L). These peaks would encompass 

both orthophosphate inorganic P and orthophosphate 

monoester organic P (Condron and others, 1997).
Chapter 7: Isolation and Characterization of Colloids 65

173.9130.7101.572.355.940.733.724.4

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

A PR13

13C NMR— April 1994

Figure 25A. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR13, April 1994.
66 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

B MLS4

13C NMR — April 1994

175.1169.2101.572.332.524.4

Figure 25B. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from MLS4, April 1994.
Chapter 7: Isolation and Characterization of Colloids 67

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

C MLS7

13C NMR — April 1994

175.1169.2101.572.355.932.524.4

Figure 25C. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from MLS7, April 1994.
68 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

D PR9

13C NMR — April 1994

176.3101.572.331.424.418.5169.257.1

Figure 25D. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR9, April 1994.
Chapter 7: Isolation and Characterization of Colloids 69

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

E PR12

13C NMR — September 1994

175.2

131.1

102.772.363.056.032.624.4

Figure 25E. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR12, September 1994.
70 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 175.2 102.7 72.3 56.0 31.4 24.4

18.6169.3

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

F PR9

13C NMR — September 1994

Figure 25F. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR9, September 1994.
Chapter 7: Isolation and Characterization of Colloids 71

PR13

15N NMR — April 1994

750 500 250 0 –250 –500 –750

PARTS PER MILLION 120.4

G

Figure 25G. Nitrogen-15 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR13, April 1994.
72 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

PR12

15N NMR — September 1994

117.7

750 500 250 0 –250 –500 –750

PARTS PER MILLION

H

Figure 25H. Nitrogen-15 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR12, September 

1994.
Chapter 7: Isolation and Characterization of Colloids 73

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

PR12

13C NMR — September 1994

174.030.323.3

I

Figure 25I. Dipolar dephased carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR12, 

September 1994.
74 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

420 300 200 100 0 –100 –140 400

PARTS PER MILLION

Thoreau's Bog

13C NMR

195.9172.9156.3128.8115.8103.971.952.232.4

J

Figure 25J. Carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid from Thoreau’s Bog.
Chapter 7: Isolation and Characterization of Colloids 75

PR12

31P NMR — September 1994

200 150 100 50 0 -50 –100 –150

PARTS PER MILLION–2.5

K

Figure 25K. Phosphorus-31 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR12, September 

1994.
76 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

PR9

31P NMR — September 1994

L

200 150 100 50 0 –50 –100 –150

PARTS PER MILLION2.2

–6.2

–5.1 –4.4

Figure 25L. Phosphorus-31 cross polarization/magic-angle spinning nuclear magnetic resonance spectometry of colloid collected from PR9, September 

1994.
Chapter 7: Isolation and Characterization of Colloids 77

Differences between colloids in recycled water 

before recharge and during recharge beneath the 

research basin are illustrated by the 13C CP/MAS NMR 

spectra. For example, compare spectra from the 

September 1994 sampling in figures 25E and F. There 

is a splitting of the carboxylic acid/amide peak in the 

spectrum from PR9, with maximums at 175.2 and 

169.3 ppm, and a relative decrease in the signal 

intensity of the methylene carbons (31.4 ppm) with 

respect to the methyl carbons (24.4 ppm). These same 

differences also exist for the April 1994 recharge 

experiment between the effluent (PR13) (fig. 25A) and 

recharged water beneath the research basin at MLS4, 

MLS7, and PR9 (figs. 25B, C, D). The peaks at 169 

ppm in the spectra of samples from below the bottom 

of the basin represent carbonate carbon. The resolution 

of the carbonate signal in these spectra corresponds to 

an increase in the ratio of inorganic to organic carbon 

in these samples compared to the colloids from the 

effluent and the research basin. One possible 

explanation is that the changes in spectra during 

recharge reflect the filtering out of algal material as the 

recycled water percolates through the bottom sediment. 

In other words, whereas the organic matter of colloids 

in the research basin and recycled water itself may be 

derived from a combination of algae and bacteria, the 

organic matter of colloids in recharged water beneath 

the research basin is derived mainly from bacteria. The 

decrease in C/N ratios of colloids during recharge, as 

shown in table 13, is consistent with this hypothesis 

insofar as C/N ratios of algae (5.6) tend to be higher 

than those of bacteria (3–5) (Rostad and others, 1997). 

It also is consistent with observations of bacterial 

transport reported in Chapter 4 on microbiological 

changes and with visual (greenish color) observations 

of algal transport, albeit to lesser depths, in these same 

samples for microbiological analyses.
78 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 8: CHARACTERIZATION OF 

DISSOLVED ORGANIC MATTER BY 

CONCENTRATION, FRACTIONATION, AND 

MOLECULAR WEIGHT DETERMINATIONS

By Larry B. Barber

The concentrations and characteristics of DOC 

(dissolved organic carbon) and sewage-derived organic 

compounds are of concern in the recharge of aquifers 

with recycled water. Both natural and synthetic organic 

matter are important due to possible direct health 

effects and the formation of disinfection byproducts by 

reactions that take place during water treatment. 

Municipal wastewaters are mixtures containing 

thousands of dissolved and particulate organic 

compounds of varying chemical structures and 

molecular weights, and their characterization can be an 

important part of evaluating possible health effects.

The fate of DOC during aquifer recharge with 

recycled water depends on a number of hydrogeologic 

and biogeochemical processes, including dispersion 

and dilution, biodegradation, and sorption. Both rate 

and extent of removal during infiltration is affected by 

the composition, which varies with the origin of the 

organic matter (domestic or industrial), the level of 

pretreatment received, and the operation dynamics of 

the infiltration process.

In this study, the fate of DOC during three 

wastewater-infiltration events was evaluated by 

comparing concentrations and characteristics in 

samples collected from wells and multilevel samplers 

beneath and near the research basin with those in 

recycled water used in recharging the basin.

Methods

Sample Collection and Field Processing

Dissolved organic carbon was characterized in 

water collected during all three recharge experiments 

described in previous chapters. Samples were analyzed 

for total organic carbon (TOC), DOC, and total 

inorganic carbon (TIC) concentration, DOC 

fractionation (DOCf), and DOC molecular-weight 

characterization (DOCmw). One-liter samples for DOC, 

DOCf, and DOCmw analysis were pressure filtered 

(20–30 lb/in2) through 0.45-μm silver membranes and 

collected in precleaned amber glass bottles. Unfiltered 

samples were collected in 40-mL amber glass bottles 

for TOC and TIC analysis.

Independent field measurements were made at 

the time of sampling for organic characterization 

measurement, and these data are reported in 

appendix 9. Specific conductance was measured using 

a temperature-compensated conductivity meter (Orion 

model 124) calibrated daily against standard reference 

solutions. Dissolved oxygen (DO) was measured using 

a temperature- and pressure-compensated DO meter 

(Orion model 820) calibrated daily against air. Sample 

pH was measured using an Orion 250 meter and an 

Orion model 9107 Triode pH electrode. The electrode 

was calibrated daily using pH 4, 7, and 10 standards. 

The samples used for detailed organic characterization 

were collected virtually concurrently—but by different 

personnel (in many cases)—with samples for 

microbiological and inorganic analyses. All field data 

are included in appendix 9 for each of the three 

recharge experiments. Some differences exist between 

these data and the field data described in the previous 

chapters on water-quality changes and given in the 

earlier appendixes, but these differences are generally 

minor.

Analytical Methods

Total and Dissolved Organic and Inorganic Carbon 

Concentration

Total and dissolved organic and inorganic carbon 

were measured by heated persulfate oxidation using an 

Oceanographic International Model 700 Carbon 

Analyzer. This method involves acidifying a 1-mL 

water sample with phosphoric acid to convert inorganic 

carbon to carbon dioxide (CO2) and sparging with 

nitrogen (N2) gas. The N2 passes through a molecular 

sieve wherein the CO2 is trapped. The trapped CO2 is 

thermally desorbed and measured using an IR 

(infrared) detector. After removal of inorganic carbon, 

sodium persulfate is added and the sample is heated to 

oxidize the organic carbon to CO2, which is then 

measured in the same way as is inorganic carbon. Each 

sample was analyzed in duplicate, and concentrations 

were calculated using a 6-point calibration curve. 

Distilled-water blanks and quality-assurance standards 

were analyzed approximately every 10 samples. The 

detection limit for this method is about 0.1 mg/L.
Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular Weight Determinations 79

Dissolved Organic Carbon Fractionation

Samples were analyzed by an automated DOCf

method that is based on the method described by 

Leenheer and Huffman (1976, 1979), Leenheer (1981), 

and Barber and others (2001). This method is based on 

chromatographic separation, using macroreticular 

resins, of the DOC into six fractions using reverse- and 

normal-phase sorption and differences in aqueous 

elution characteristics.

A variety of macroreticular sorption resins were 

used in the DOCf method. The reverse-phase adsorbent 

used in the method was Supelite DAX-8 (Supelco), an 

acrylic ester copolymer, or Amberchrom CG-71m 

(Supelco), a moderately polar polymethacrylate 

polymer with a smaller particle size than that of 

DAX-8. This material is equivalent to the XAD-8 resin 

used elsewhere in this report. Values obtained using 

both resins are reported for several samples from the 

second and third recharge experiments. The ionexchange resins that were used are based on a crosslinked styrene divinylbenzene copolymer. The anionexchange resin was BIO-RAD AG MP 1, a Type I 

strong-base anion-exchange resin (in Cl-

 form) with 

quaternary ammonium basic functional groups or 

Amberlite IRA 910 (Rhom and Hass), which has 

Type II dimethylethanolamine basic functional groups. 

The cation-exchange resin was BIO-RAD AG MP 50 

or Amberlite 200 (Rhom and Hass); both are Type I 

strong-acid cation-exchange resins with sulfonic acid 

functional groups (in H+ form). The resins were custom 

packed by Waters Chromatography (Medford, 

Massachusetts) into long-body SepPak cartridges using 

radial compression technology.

The DOCf method was automated using a Waters 

Millilab 1A solid-phase extraction robotics 

workstation. Each cartridge (pore volume 

approximately 1 mL) was conditioned immediately 

prior to use at flow rates through the cartridges of 1–4 

mL/min.

This method separates the DOC into six 

fractions. The filtered water is passed through a DAX-8 

or GC-71m (reverse-phase) column at neutral pH, and 

the effluent is collected. Under these conditions, the 

hydrophobic neutral (HPOn) and the hydrophobic base 

(HPOb) fractions are sorbed to the resin. The HPOb

fraction is then isolated by extracting the resin with 

0.1 N sulfuric acid, leaving the HPOn fraction to be 

determined by mass difference. The column effluent 

from the original sample is acidified to pH 2 using 

sulfuric acid, passed through the reverse-phase column 

again, and collected. The hydrophobic acid (HPOa) 

fraction is then determined by mass difference between 

the column influent and effluent. The DOC that passes 

through the reverse-phase column at pH 2 is considered 

to be hydrophilic (HPI). The HPI DOC is further 

separated into a base (HPIb) fraction by passing the 

sample through cation-exchange resin and into an acid 

fraction (HPIa) by passing the cation-exchange column 

effluent through an anion-exchange resin. The final 

effluent from the ion-exchange resins that has passed 

through all of the sorbents is then the hydrophilic 

neutral fraction (HPIn).

By following this entire procedure for each 

DOCf sample, one obtains 13 subsamples for DOC 

analysis consisting of blanks, cartridge influents, 

cartridge effluents, and extracts. Each set of 

subsamples is analyzed as a group and includes a water 

blank and two DOC standards containing 1 and 5 mg/L 

carbon. Analyses of the various fractions were 

performed by persulfate oxidation as described in the 

preceding section. Examples of types or classes of 

organic compounds that could be present in each of the 

six DOC fractions are shown in figure 24.

Dissolved Organic Carbon Molecular-Weight 

Characterization

 Aliquots from samples filtered through the silver 

membrane were fractionated by ultrafiltration to 

determine the molecular-weight characteristics of the 

DOC. Fractionation involved passing the sample 

through a parallel set of membranes (Diaflo 

Ultrafilters, Amicon, Beverly, Massachusetts) with 

nominal pore sizes that result in nominal molecularweight cutoffs at 100,000 da (daltons) (YM100 filter), 

30,000 da (YM30 filter), and 3,000 da (YM3 filter). An 

80-mL sample was placed in a stirred filtration 

chamber containing the appropriate ultrafilter, the 

chamber was pressurized with N2 to 60–70 lb/in2, the 

first 20 mL of sample to pass through the filter was 

discarded, and the next 14 mL was collected and 

analyzed for DOC as described above. The percentage 

of DOC with molecular weights less than the three 

selected size cutoffs is determined by dividing the 

DOC of the filtrate by the initial DOC of the sample.
80 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Results and Discussion

First Recharge Experiment

As was noted in descriptions in previous chapters 

of the hydrologic conditions at the research basin 

during the first recharge experiment in August 1993, 

the addition of very little recycled water was required 

to maintain the water level in the basin once it had been 

initially filled (the initial filling required less than 

2 days). The slow infiltration was attributed to 

concurrent delivery of recycled water to the adjacent 

spreading grounds, which resulted in ground-water 

levels above the floor of the research basin (fig. 9). The 

result is that even 13 days after delivery of recycled 

water to the research basin began on August 10, the 

water had percolated only to a depth of about 10 ft 

below the basin floor, as evidenced by specificconductance data given in appendix 8.

Organic Carbon Concentration

The results of DOC concentration analysis for 

samples collected August 23, 1993, are given in 

table 14. The data indicate about a 30-percent reduction 

in DOC concentration between the research basin 

(PR12) and soil water to a depth of 10 ft (MLS4–10) 

beneath the research-basin floor, an interval over which 

specific conductance is nearly constant.

Dissolved Organic Carbon Fractionation

Results of the DOCf analysis are summarized in 

table 14 and are illustrated on “stiff-type” diagrams 

(Stiff, 1951) in figure 26. Because the analytical 

method was not yet fully developed at the time of this 

sampling, the DOCf analysis was done by Huffman 

Laboratories, Denver, Colorado. Although there are 

some minor differences between the methods they used 

and those used by the USGS for the next two recharge 

experiments, the principles are the same and results are 

therefore considered comparable.

Some readily apparent differences (shown in 

fig. 26) occur in relative proportions of the six different 

fractions among the various samples. However, in 

assessing possible changes in composition during 

recharge, one must exclude from consideration data 

from more than 10 ft below the research-basin floor 

because percolation of recharge at the research basin 

did not extend beyond this depth during the August 

1993 experiment. The diagrams seem to indicate a 

slight shift from hydrophobic predominance in the 

effluent (PR13) to hydrophilic predominance in the 

subsurface (MLS4). This shift is accompanied by an 

increase in the acid (HPOa and HPIa) and decrease in 

the neutral (HPOn and HPIn) components of the 

hydrophobic and hydrophilic fractions, respectively. 

However, even such modest differences in composition 

are no longer discernible when comparisons are 

extended to include data in table 14 from the research 

basin itself (PR12) and from depths below 4 ft 

(MLS5–10).

Table 14. Dissolved organic carbon (DOC) fractionation data for samples collected August 23, 1993, at the research basin, Montebello Forebay, Los Angeles 

County, California

[mg/L, milligrams per liter; <, less than; samples analyzed by Huffman Laboratories, Denver, Colorado]

Sample 

identifier

Total DOC

(mg/L)

Hydrophobic fractions

 (percent)

Hydrophilic fractions 

(percent)

Total Acid Base Neutral Total Acid Base Neutral

PR13 7.2 53 18 1 35 47 15 8 24

PR12 at surface 7.5 34 21 <1 14 66 48 11 8

PR12 at bottom 7.8 37 19 <1 18 63 42 9 12

MLS4 5.8 40 26 <1 14 60 47 13 <1

MLS5 5.4 35 22 <1 11 65 50 13 2

MLS6 5.4 46 20 <1 26 54 28 13 15

MLS7 6.1 41 16 <1 26 59 26 7 25

MLS8 5.2 42 21 2 19 58 42 4 10

MLS10 3.6 28 17 <1 11 72 44 17 11

MLS11 3.7 54 8 <1 46 46 22 16 8

PR9 2.0 40 35 <1 5 60 15 10 30

PR8 2.3 52 4 <1 48 48 4 9 35
Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular Weight Determinations 81

August 1993

Hydrophobic (%) Hydrophilic (%)

60 50 40 40 30 30 20 20 10 10 50 60

Acid

Neutral

Base

Total

Acid

Neutral

Base

Total

Acid

Neutral

Base

Total

Acid

Neutral

Base

Total

Acid

Neutral

Base

Total

PR13

MLS4

MLS11

PR9

PR8

Figure 26. Relative proportions of six dissolved organic carbon fractions at the research basin, Montebello Forebay, Los Angeles County, California, during 

the August 1993 recharge experiment.
82 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Second Recharge Experiment

The second recharge event started at 20:00 April 

4, 1994, and ended at 17:00 April 21, 1994. During the 

17 days of infiltration 12.5 acre-ft of effluent was 

recharged through the research basin. A total of 42 

samples were collected from the wastewater effluent, 

the infiltration basin, wells, and MLS ports for organic 

analysis. Samples were collected 1 day before 

discharge to the basin, and 1, 2, 3, 4, and 58 days after 

infiltration began. The day 58 sample was collected 41 

days after filling of the basin stopped.

Field measurements obtained on samples 

collected during the second recharge experiment for 

organic carbon characterization are consistent with the 

pattern described previously in Chapter 5 on waterquality changes. For example, chloride data in 

figure 12 show that by the second day of recharge, 

April 6, 1994, recharged water had completely, or 

nearly completely, displaced preexisting water in the 

soil to a depth of about 20 ft. There was also 

substantial, though less complete, displacement at a 

depth of 25 ft (PR9)—unlike in August 1993. Specificconductance data (appendix 9) on the samples 

collected April 7, 1994, for organic carbon 

characterization yield a similar result; conductance 

values were nearly constant in the upper 19 ft and 

decreased slightly at 20 (MLS20) and 25 ft (PR9). A 

DO maximum, centered at a depth of 11 ft beneath the 

basin according to the data in appendix 9, also is 

confirmed in figure 20. The pH was slightly above 7 in 

the research basin and slightly below 7 beneath it; the 

difference was only about 0.2 pH unit. Such a decrease 

is consistent with ammonia oxidation (nitrification)—

which, on the basis of the nitrogen profiles in figure 18, 

seems to be occurring—during the first few days of 

recharge. And finally, there is only a very slight 

decrease in temperature with increasing depth beneath 

the research basin as recycled water with a temperature 

near 24°C displaces cooler preexisting soil moisture 

having a temperature near 22°C.

Organic Carbon Concentration

Measurements of DOC and TOC concentration 

on selected samples indicate that only1 percent, or less, 

of the aqueous organic carbon beneath the research 

basin is present as particles larger than 0.45 μm 

(table 15). This finding can be compared with data in 

Chapter 7 that showed that the colloidal contribution, 

though minor relative to total and dissolved (0.45-μm) 

organic carbon, is about an order of magnitude greater 

than the contribution from particles larger than 0.45 

μm. As expected, the effluent itself has a higher 

particulate organic carbon concentration (POC) at 

about 5 percent, most of which apparently does not 

infiltrate intact beneath the research basin during 

recharge experiments. The upgradient background well 

(-7J1) and a well 2,500 ft south of the research basin 

(-19C1) also had measurable quantities of POC, but 

because these wells are only infrequently sampled, the 

POC could be artifacts caused by sloughing of material 

from the soil during pumping to collect the sample.

The DOC concentration data (table 16) beneath 

the research basin indicate that concentration increases 

rapidly on successive days, with some temporal and 

spatial variability in the early stages, from 1.5 to 

2.2 mg/L before recharge to a nearly uniform level of 

about 6 mg/L 3 days after recharge began. The 

concentration after 3 days represents about a one-third 

reduction in DOC concentration in comparison with 

the approximately 9 to 10 mg/L present in the recycled 

water itself. The DOC concentrations then declined 

after the recharge experiment was discontinued, 

although even 41 days later, on June 1, concentrations 

still exceeded those that existed before the recharge 

experiment began. This subsequent decline was 

attributed, on the basis of information shown in

figure 12B, to partial replacement of the high-DOC 

recycled water with lower-DOC ambient ground water 

after recharge is discontinued.
Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular Weight Determinations 83

Table 15. Selected organic and inorganic carbon data and analytical precision information for samples collected during the April and September 1994 

recharge experiments at the research basin, Montebello Forebay, Los Angeles County, California

[Data for April 7 except as noted; DOC, dissolved organic carbon; TOC, total organic carbon; POC, particulate organic carbon; TIC, total inorganic carbon; 

mg/L, milligrams per liter; <, less than; —, no data]

1Precision ranges from <0.1 to 0.3 based on replicate anayses.

Sample identifier DOC1

(mg/L)

TOC

(mg/L)

POC

(percent)

TIC

(mg/L)

PR13 (April 5) 9.7 10.2 5.2 49.9

PR12 (April 6) 9.2 9.1 1.2 52.3

MLS4 (April 6) 3.6 3.6 .6 37.1

MLS7 4.1 4.1 .5 44.0

MLS10 5.8 5.9 1.9 47.2

MLS15 5.9 5.7 3.3 44.0

MLS20 4.4 4.2 4.1 42.5

PR11 2.5 2.5 .8 43.3

PR10 2.1 2.1 .9 41.6

PR9 (April 5) 2.5 2.5 .0 44.5

PR9 4.5 — — 45.9

PR8 2.3 — — 43.6

2S/11W-19C1 3.5 4.2 18.2 46.7

2S/11W-18P1 3.6 3.6 .8 46.7

2S/11W-7J1 1.6 1.7 6.0 59.7

Field blank — .1 — —

Filter blank — .1 — —

Effluent from Bolston Filter

PR12 8.4 — — —

MLS4 4.8 — — —

MLS7 5.9 — — —

PR9 5.3 — — —

Effluent from Amicon Ultrafilter

PR12 7.9 — — —

MLS4 4.9 — — —

MLS7 5.6 — — —

PR9 4.7 — — —

September 1994

PR13 8.0 8.3 <1 45.0

MLS15 5.4 5.3 2

PR9 5.5 5.5 <1 48.2

PR11 5.4 5.4 <1 48.3

WP5 4.0 4.1 <1 44.3

2S/11W-7J1 1.4 1.9 <1 61.3
84 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

The fairly uniform pattern described does not 

exist, however, at very shallow depths, especially at 4 ft 

(MLS4), where DOC concentration actually increased 

to 7.8 mg/L on June 1. Such a high concentration could 

indicate desorption from the solid to the aqueous phase. 

Even the chloride concentration at 142 mg/L in MLS4 

on June 1 exceeds the concentration (range 125 to 

139 mg/L) in the research basin (PR12) during the 

period April 4–21 when effluent was being delivered to 

the research basin (appendix 3). The high chloride level 

is consistent with concentration by partial evaporation 

during the drying cycle that follows recharge.

Molecular Weight of Dissolved Organic Carbon

The molecular-weight characterization data in 

table 17 indicate that the concentration of nearly all 

DOC beneath the basin, and in the background well 

(-7J1), is less than 30,000 da (equivalent to 0.005-μm 

filter pore size). There is some evidence for preferential 

removal of higher-molecular-weight DOC during 

recharge as the proportion less than 3,000 da increases 

from about 

70 percent in the effluent (PR13) to about 80 percent 

beneath the research basin.

Table 16. Dissolved (DOC) and total (TOC) organic carbon concentrations before (April 4), during, and after (June 1) the 17-day recharge experiment in April 

1994 at the research basin, Montebello Forebay, Los Angeles County, California

[April 7 data are for TOC, all other data are for DOC; —, no data]

Sample

 identifier

Organic carbon concentration, in milligrams per liter

April 4 April 5 April 6 April 7 April 8 June 1

PR13 — 9.7 9.2 — 8.3 —

MLS4 1.8 3.6 — 6.3 6.3 7.8

MLS5 1.8 — — 6.0 5.0 4.1

MLS6 1.7 — — 5.6 5.0 4.1

MLS7 1.7 — 4.1 5.5 4.6 3.4

MLS8 2.0 — — 5.6 4.8 3.6

MLS9 1.5 — — 5.9 5.7 2.2

MLS10 1.8 — 5.8 6.1 5.9 2.5

MLS11 — — — 5.8 — —

MLS12 — — — 6.0 — —

MLS13 — — — 5.8 — —

MLS14 — — — 5.9 — —

MLS15 2.0 — 5.9 5.9 — 3.6

MLS16 — — — 5.4 — —

MLS17 — — — 5.9 — —

MLS18 — — — 5.5 — —

MLS19 — — — 5.5 — —

MLS20 2.2 — 4.4 4.2 — 2.8

PR9 1.9 2.5 — 4.5 2.3 3.6
Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular Weight Determinations 85

Dissolved Organic Carbon Fractionation

The results of DOC fractionation during the 

second recharge experiment are presented in table 18

and in depth-related profiles in figure 27. Patterns are 

more easily discernible than during the first recharge 

experiment—in part because more data were collected, 

but also because the recycled water penetrated to a 

greater depth beneath the research basin than during 

the first experiment. This is evident from the change in 

relative concentrations at the 25-ft depth (PR9) 

between April 5 and April 7, when increasing amounts 

of recycled water reach this depth. (Note only the 

April 5 data are shown in figure 27—if the April 7 data 

were plotted instead, the difference [shift in profile] 

from shallower depths would appear to be less marked 

than depicted in the figure). The data in table 18

suggest a slight decrease in the hydrophilic component 

during recharge from 66 percent in the research basin 

(PR12) to about 60 percent beneath the basin. 

However, this small difference is less than the average 

difference obtained by using two different resins 

(CG-71m or DAX-8) for dual sets of values on seven 

samples included in table 18 and is therefore not 

significant.

The profiles to a depth of 25 ft, the depth to 

which recycled water penetrated, show a general 

decrease with increasing depth in both the hydrophilic 

acid (HPIa) and hydrophilic base (HPIb) fractions. This 

pattern is matched by a rather uniform increase in the 

hydrophobic neutral (HPOn) and hydrophobic acid 

(HPOa) fractions, as would be expected if there were 

preferential removal of the hydrophilic component 

from the DOC. Also, it is clear, upon comparison of the 

fractionation data in these profiles with results at the 

50-foot depth, that recycled water during the recharge 

experiment does not penetrate beneath the clay lens 

that is present between the deeper (PR8 and PR10) and 

shallower (PR9 and PR11) piezometers (table 18 and 

fig. 27).

Table 17. Dissolved organic carbon (DOC) molecular-weight distribution for samples collected at the research basin, Montebello Forebay, Los Angeles 

County, California, in April and September 1994

[mg/L, milligrams per liter; SRFA, Suwannee River fulvic acid; KHP, potassium hydrogen phthalate standard; —. no data]

Sample

identifier

Total

DOC

(mg/L)

DOC content in percent size fraction less than

3,000 daltons 30,000 daltons 100,000 daltons

April 1994

PR13 8.2 69 82 —

MLS4 3.2 81 93 95

MLS10 5.1 78 93 95

MLS15 5.3 79 93 93

MLS20 3.8 81 100 98

PR9 (April 5) 2.4 70 99 101

PR9 (April 7) 3.9 85 104 98

PR8 2.2 108 96 93

September 1994

PR13 8.2 58 79 85

MLS15 5.2 69 98 97

PR9 5.9 75 91 89

PR11 5.5 75 94 93

WP5 4.2 77 97 101

2S/11W-7J1 1.3 57 102 103

SRFA 3.6 8 75 97

KHP 5.2 23 82 100
86 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

RELATIVE CONCENTRATION, IN PERCENT

0 10 20 30 40 50

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0

10

20

30

40

50

Acid

Base

Neutral

Hydrophobic Hydrophilic

Figure 27. Relative concentrations of six dissolved organic carbon fractions in PR13 (effluent depicted as zero depth) and beneath the research basin 

during the April 1994 recharge experiment, Montebello Forebay, Los Angeles County, California.
Chapter 8: Characterization of Dissolved Organic Matter by Concentration, Fractionation, and Molecular Weight Determinations 87

Third Recharge Experiment

 At the time of the last of the three recharge 

experiments, in September 1994, ground-water levels 

were much lower than during the first two experiments, 

with an approximately 10- to 15-foot unsaturated zone 

existing beneath the research basin (fig. 9). Hence, 

recycled water was able to infiltrate rapidly and 

displace preexisting moisture beneath the research 

basin. The profile for specific conductance was 

constant at about 1,090 μS/cm to a depth of 25 ft, a 

confirmation of virtually complete displacement 

(shown by data in appendixes 4 and 9), when sampled 

about 2 weeks after recharge had begun.

Organic Carbon Concentration

The decrease in DOC from 8.2 mg/L in the 

effluent (PR13) to 5.2–5.9 at depths of 15 and 25 ft 

(MLS15, PR9, and PR11) beneath the research basin 

(table 17) represents a 32-percent reduction in aqueous 

DOC concentration. The value is nearly identical to 

those calculated from the first two recharge 

experiments and suggests that reduction in DOC (also 

TOC) concentration during recharge is independent 

(within the sensitivity of the experimental results) of 

unsaturated-zone thickness and independent, as well, 

of environmental properties such as redox potential 

that do affect nitrogen removal.

Table 18. Dissolved organic carbon (DOC) fractionation data for samples collected at the research basin, Montebello Forebay, Los Angeles County, 

California, April 1994

[A, data obtained using CG-71m resin; B, data obtained using DAX-8 resin; mg/L, milligrams per liter; SRFA, Suwannee River fulvic acid; <, less than; —, 

no data]

Sample

identifier

Total

DOC

(mg/L)

Hydrophobic fractions 

(percent)

Hydrophilic fractions

(percent)

Total Acid Base Neutral Total Acid Base Neutral

PR13 A 9.1 38 23 4 11 62 32 26 4

PR13 B 8.3 47 19 2 26 53 26 18 9

PR12 A — — — — — — — — —

PR12 B 7.8 34 23 2 8 66 37 22 7

MLS4 A 3.1 43 35 1 8 57 38 15 4

MLS4 B — — — — — — — — —

MLS7 A 3.6 42 21 <1 20 58 31 15 12

MLS7 B 3.5 40 32 <1 7 60 35 15 10

MLS10 B 5.1 38 25 4 9 62 33 23 6

MLS15 B 5.4 40 22 4 14 60 30 17 13

MLS20 B 3.9 43 27 <1 16 57 31 14 12

PR9 (April 5) B 2.5 56 37 <1 18 44 25 13 6

PR9 (April 7) A 3.9 39 25 4 10 61 30 18 13

PR9 (April 7) B 3.8 36 17 4 15 64 32 20 12

PR8 B 2.5 58 19 1 38 42 18 12 12

PR10 B 2.4 54 17 2 34 46 20 16 10

PR11 A 2.4 63 29 <1 35 37 4 2 31

PR11 B 2.3 45 27 <1 17 55 7 8 40

2S/11W-19C1 B 3.0 41 31 <1 9 59 20 12 27

2S/11W-18P1 B 3.1 38 19 6 13 62 16 8 37

2S/11W-7J1 B 1.4 25 25 <1 <1 75 34 18 23

SRFA A 4.7 71 46 4 20 29 22 7 <1

SRFA B 4.6 64 44 3 17 36 27 2 7
88 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Molecular Weight of Dissolved Organic Carbon

The results of molecular-weight characterization 

for the DOC during the third recharge experiment, 

when a substantial unsaturated zone existed, are similar 

to those from the second recharge experiment, when 

almost no unsaturated zone was present. There is some 

slight evidence that movement through an unsaturated 

zone is less effective in removing (presumably by 

sorption) higher-molecular-weight DOC; this evidence 

is based on the observation that the proportion of DOC 

greater than 3,000 da beneath the research basin 

increases from about 20 percent in the second recharge 

experiment to about 30 percent in the third experiment 

(percentages calculated from data in table 17). A 

comparison with the Suwannee River fulvic acid (a 

standard commonly used for comparison), where 

92 percent of the DOC is greater than 3,000 da, 

confirms the expected finding that ground-water DOC 

at the study site is of lower molecular weight than is 

typical for natural organic carbon in surface water 

(Barber and others, 1995a, b).

Dissolved Organic Carbon Fractionation

The analytical method was modified slightly 

from the second recharge experiment by using a 

smaller-particle-size resin for initial isolation of the 

hydrophobic component. This change results in a 

slightly higher HPOa fraction. The data in table 19

indicate nearly equal amounts of hydrophobic and 

hydrophilic DOC in the effluent (PR13), whereas the 

hydrophilic component was slightly greater in the 

second recharge experiment (table 18). Proportions of 

the six fractions beneath the research basin were 

generally about the same in both experiments; however, 

data from too few depths (15 and 25 ft only) were 

collected in the third experiment to reliably assign 

differences. 

A rather large difference was observed between 

the April and September samples in the relative 

proportion of the six fractions at the background well

(-7J1). Predominance shifted from hydrophilic

(75 percent in table 18) in the second recharge 

experiment to hydrophobic (64 percent in table 19) in 

the third experiment. This shift was accompanied by a 

large increase in the HPOa fraction and decreases in the 

HPIa and HPIb fractions. Such large variations in such 

a short time suggest that this background (or 

upgradient) monitoring well may be subject to seasonal 

changes that affect natural recharge and water levels, 

and perhaps even operations at the spreading grounds 

itself.

Table 19. Dissolved organic carbon (DOC) fractionation data for samples collected at the research basin, Montebello Forebay, Los Angeles County, 

California, September 1994

[mg/L, milligrams per liter; A, data obtained using CG-71m resin; B, data obtained using DAX-8 resin]

Sample

identifier

Total

DOC

(mg/L)

Hydrophobic fractions 

(percent)

Hydrophilic fractions 

(percent)

Total Acid Base Neutral Total Acid Base Neutral

PR13 7.6 50 35 1 13 50 25 17 8

MLS15 4.8 47 34 1 13 53 27 13 12

PR9 A 5.5 23 8 1 13 77 46 19 12

PR9 B 5.2 48 39 1 8 52 27 14 12

PR 11 5.1 48 36 1 11 52 29 14 10

WP5 3.9 48 38 1 9 52 27 10 15

2S/11W-7J1 1.5 64 38 1 26 36 2 5 28
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 89

CHAPTER 9: CHARACTERIZATION OF 

DISSOLVED ORGANIC MATTER BY 

INFRARED AND ULTRAVIOLET/VISIBLE 

SPECTROMETRY

By Jerry A. Leenheer and Ted I. Noyes

Infrared spectrometry is especially useful for 

determining oxygen, nitrogen, and sulfur functional 

groups in organic-matter isolates, and methyl and 

methylene groups in hydrocarbon structures. However, 

interpreting IR spectra can be more complex than 

interpreting 13C-NMR spectra. Purity of the isolates is 

a more important requirement for IR than for 

13C-NMR owing to IR spectral interferences from 

ammonium, nitrate, nitrite, phosphate, silica, sulfate, 

and water. Large concentrations of ammonium, nitrate, 

and phosphate in recycled water made necessary the 

development of specific fractionation and isolation 

methods that are not normally required for natural 

waters. Therefore, the primary objective for the April 

and September 1994 samplings was to develop 

methods for comprehensive fractionation, isolation, 

and IR characterization of DOC; a secondary objective 

was to apply these methods to observe water-quality 

changes during infiltration of reclaimed water from the 

research basin into the subsurface.

Fractionation and Isolation Methods

For the ultrafiltered water samples (method 

described in Chapter 6) obtained during the April 4–7, 

1994, sampling, the preparative DOC fractionation 

approach (Leenheer and Noyes, 1984) using Amberlite 

XAD-8, MSC-1H, and Duolite A-7 resin columns in 

series was used with the following modifications:

(1) The 20-L ultrafiltered sample was adjusted to 

pH 4 and vacuum-evaporated to 0.5 L. The evaporation 

under acidic conditions eliminates carbonates and 

maintains ammonium in the cationic form to minimize 

ammonia reactions with organic matter.

(2) Hydrophobic DOC was adsorbed from the 

sample concentrate on a 150-mL bed-volume column 

of XAD-8 resin. The low ratio of sample concentrate 

volume to resin volume enabled greater recoveries of 

hydrophobic solutes with column-capacity factors (k') 

that are lower than those from earlier methods.

(3) Most of the inorganic salts in the hydrophilic 

DOC fraction that did not sorb to XAD-8 resin were 

removed by zeotrophic distillation with acetic acid 

(Aiken and Leenheer, 1993). Removal of these salts 

allowed the sorption of hydrophilic bases on the

MSC-1H resin (100-mL column) and hydrophilic acids 

on the A-7 resin (100-mL column) using much smaller 

volumes of these ion-exchange resins than if salts had 

not been removed.

(4) The final desalting of both the hydrophobic 

and hydrophilic base fractions was done on Amberlite 

XAD-4 resin using water volumes that recovered 

solutes with k' values greater than 4. A 75-percent 

acetonitrile/25-percent water (volume ratio) mixture 

was used for elution of the base fractions. 

(5) Nitrate, phosphate, and sulfate were major 

salt interferants in the hydrophilic acid fraction eluted 

with dilute sodium hydroxide (NaOH) from the A-7 

resin. Phosphate was removed by precipitation as 

magnesium ammonium phosphate (Fischer, 1961), and 

nitrate and sulfate were precipitated as their barium 

salts, insoluble in acetic acid (Audrieth and Kleinberg, 

1953), after removal of water by zeotrophic distillation. 
90 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Additional changes in fractionation and isolation 

methods were made for samples collected during 

September 19–22, 1994. The main objective of these 

methods changes was to separate and characterize 

discrete compound-class contaminants such as 

alkylphenol polyethyoxy carboxylates (APECs), 

aromatic sulfonates, alkylsulfates and arylsulfates, and 

a blue dye, from organic matter of natural origin such 

as carbohydrates, fulvic acid, and proteins. 

Special care was taken during the processing of 

these samples to prevent exposure to extremes of low 

pH and heat that would hydrolyze alkylsulfates and 

arylsulfates that might be present from sulfate-ester 

surfactants. The 20-L samples were vacuum-rotary 

evaporated without pH adjustment to 0.5 L. The 

concentrates were then acidified to pH 3, and purged 

with nitrogen to remove carbonates. The pH of the 

samples was adjusted to 7 and the samples were 

vacuum-evaporated to 50 mL. These concentrates were 

reacidified to pH 2 and extracted using 200 mL of 

diethylether to remove the APEC contaminants and 

other extractable acids. The aqueous phase was 

neutralized to pH 8 and passed through a sodiumsaturated MSC-1 column to remove divalent and 

trivalent cations. The samples were evaporated to 

dryness and the salts were extracted using methanol, an 

optimum solvent for sodium salts of sulfate esters 

(Paulson, 1976). The extract was evaporated to dryness 

and redissolved in water. Both the methanol-insoluble 

salts and the methanol-soluble salts were then 

fractionated using the same procedure as for the 

previous samples. This procedure was verified using 

sodium methyl sulfate and sodium dodecysulfate to 

minimize sulfate ester hydrolysis.

Hydrophobic acid fractions were subfractionated 

by readsorbing the acid form of these fractions on a 20-

mL column of silica gel and sequentially eluting with 

methylene chloride, ethyl acetate, acetone, 75-percent 

acetone/25-percent 2-propanol, methanol, 75-percent 

acetonitrile/25-percent water, and 0.3 M oxalic acid. 

The HPOa,n fraction that contained a blue dye was 

similarly applied to the silica gel column and eluted 

with 50-percent acetone/50-percent 2-propanol, 

50-percent acetonitrile/50-percent 2-propanol, and 

75-percent acetonitrile/25-percent water. The blue dye 

eluted with the final fraction.

Not all of these procedures were applied to each 

sample of the September 1994 sampling. The 

procedures evolved and were modified as findings from 

each previous sample became known.

Infrared Spectral Characterizations

Infrared spectra of 2–5 mg of sample-fraction 

isolates in KBr pellets were determined on a Perkin 

Elmer Model 580 IR Spectrometer with dispersive 

optics and a thermocouple detector. A few spectra of 

organic standards were determined on a Perkin Elmer 

System 2000 Fourier Transform Infrared Spectrometer 

using a pulsed-laser source and deuterated triglycine 

sulfate detector. 

 The sulfophenyl carboxylate-8 (SPC-8) and 

dialkyltetraline- and dialkylindane-sulfonate (DATS) 

standards were obtained from M. L. Trehey of 

Monsanto. The neutral alkylphenol polyethoxylate 

surfactant (Triton X-100) was obtained from Rohm and 

Haas, and the anionic aromatic sulfonate surfactant was 

obtained from Alconox. The nonylphenol 

1-3-ethyoxylate (Aldrich Chemical) and the 

nonylphenol-1-ethoxy carboxylic acid (Kolb 

Chemical) were obtained from J.C. Field of Oregon 

State University. 

Twenty liters of ultrafiltered water from the 

effluent source (PR13) of the reclaimed water that is 

delivered to the research basin was sampled 

April 5, 1994. The masses and fraction percentages of 

dissolved organic matter obtained from the preparative 

DOC fractionation of this water are presented in 

table 20. The total recovered DOC of 10.92 mg/L in 

table 20 compares well with the measured DOC of 

9.69 mg/L, considering uncertainties in the percentagecarbon values of the fractions. Therefore, the 

fractionation and isolation are comprehensive in terms 

of mass recovery.
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 91

Infrared spectra of the DOC fractions given in 

table 20 are shown in figure 28. The hydrophobic 

fractions (spectra A, B, and C) have much stronger 

peaks for the hydrocarbon stretching frequencies at 

3,000–2,860 cm-1 and bending frequencies at 

1,440–1,380 cm-1 than are found for the hydrophilic 

fractions (spectra D, E, and F). The acid fractions 

(spectra B and D) are dominated by the carboxylic acid 

peak at 1,720 cm-1, but aromatic sulfonic acids also are 

important components, as indicated by sharply defined 

peaks at 1,040 and 1,012 cm-1. The base fractions 

(spectra C and E) are highly proteinaceous, as indicated 

by the amide-1 peak at 1,660 cm-1 and amide 2 peak at 

1,550 cm-1. Lesser amounts of these amide peaks are 

found in the HPOn (spectra A), HPIa (spectra D), and 

HPIn (spectra F) fractions. The HPIn fraction is 

dominated by carbohydrates, as indicated by the strong 

carbonyl-oxygen (C-O) stretch band from 1,150 to 

1,050 cm-1, but the broad C-O stretch band centered at 

1,720 cm-1 is indicative of acids, esters, and amides 

that exist as neutral species by themselves or possibly 

in complexed forms with borate or silica. Peaks that 

indicate inorganic species are absent in these spectra—

with the exception of the HPOn fraction, which 

contains a small quantity of silicic acid as indicated by 

peaks at 1,130, 960, and 470 cm-1. 

The reclaimed-water effluent was resampled 

from the research basin September 21, 1994, and 

fractionated to obtain additional compound-class 

information. The IR spectra of DOC fractions from this 

sample are shown in figure 29. This fractionation 

detected only trace amounts of organic sulfate esters in 

spectra B and E; note the peak at 1,065 cm-1, which is 

indicative of sulfate esters (Paulson, 1976). The sharp 

peak at 1,513 cm-1 was fractionated almost completely 

into the ether-extract fraction (spectrum A) and was 

tentatively identified from comparison of standard IR 

spectra (Pouchert, 1985) as an aromatic-ring vibration 

that is strong in 1,4-substituted alkoxy compounds. 

This peak may be indicative of APEC metabolites from 

neutral surfactant degradation. In the hydrophobic 

neutral fractions (spectra B and D), the strong amide-1 

peak at 1,650 cm-1 is accompanied by a weak amide-2 

peak at 1,550 cm-1 and a peak of medium intensity at 

1,410 cm-1. This amide peak pattern is found for cyclic 

secondary amides (Pouchert, 1985) such as 

pyrimidines found in nucleic acids. Pyrimidines 

previously have been reported in municipal sewage 

effluents (Pitt and others, 1975). Sulfonic acids were 

again found as major components of the acid fractions, 

as indicated by the peak at 1,040 cm-1 (spectra 

C and F), but the absence of the 1,012 cm-1 peak in the 

hydrophilic acids of spectra F indicates that these 

sulfonic acids are not 1,4-substituted sulfonic acids.

A water sample collected from well PR11 on 

September 19, 1994, was subjected to the most 

extensive hydrophobic DOC fractionation in an attempt 

to separate specific contaminant classes in infiltrated 

reclaimed water from non-specific fulvic acids. The IR 

spectra of the major hydrophobic fractions of this 

sample are shown in figure 30. The ether-extractable 

acids (spectrum A) contain the APEC contaminants, 

tentatively identified by the sharp peak at 1,513 cm-1. 

The sharp peak at 1,385 cm-1 in this spectrum is nitrate. 

Aromatic sulfonic acids are a major component of 

spectrum D and a minor component of spectrum C, as 

indicated by peaks at 1,185, 1,130, 1,040, 1,012, 625, 

and 585 cm-1.

Table 20. Preparative dissolved organic carbon (DOC) fractionating data 

for reclaimed-water effluent (PR13) collected at the research basin, 

Montebello Forebay, Los Angeles County, California, April 5, 1994 

[mg, milligram] 

Fraction Weight

(mg)

Percentage

Dissolved

organic

carbon

Hydrophobic neutrals (HPOn) 58.7 13.4 1.46

Hydrophobic acids (HPOa) 209.8 48.0 5.24

Hydrophobic bases (HPOb) 19.1 4.4 .48

Hydrophilic acids (HPIa) 64.0 14.6 1.60

Hydrophilic bases (HPIb) 14.9 3.4 .37

Hydrophilic neutrals (HPIn) 71.0 16.2 1.77

Total 437.5 100 10.92
92 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

3,500 2,500 2,000 1, 3,000 800 1,600 1,400 1,200 1,000 800 600 400

A

B

C

D

E

F

ABSORBANCE

WAVELENGTH, IN RECIPROCAL CENTIMETERS

Figure 28. Infrared spectra of dissolved organic carbon (DOC) fractions from reclaimed-water effluent (PR13) sampled April 5, 1994, at the research basin, 

Montebello Forebay, Los Angeles County, California: hydrophobic neutral fraction (spectrum A); hydrophobic acid fraction (spectrum B); hydrophobic base 

fraction (spectrum C); hydrophilic acid fraction (spectrum D); hydrophilic base fraction (spectrum E); and hydrophilic neutral fraction (spectrum F).
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 93

3,500

WAVELENGTH, IN RECIPROCAL CENTIMETERS

3,000 2,500 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400

A

B

C

D

E

F

ABSORBANCE

Figure 29. Infrared spectra of dissolved organic carbon (DOC) fractions in reclaimed water sampled from the research basin (PR12) September 21, 1994, 

Montebello Forebay, Los Angeles County, California: ether-extractable acids (spectrum A); hydrophobic neutral fraction of methanol-soluble extract 

(spectrum B); hydrophobic acid fraction of methanol-soluble extract (spectrum C); hydrophobic neutral fraction of methanol-insoluble extract (spectrum D); 

hydrophobic acid fraction of methanol-insoluble extract (spectrum E); and hydrophilic acid fraction of methanol-insoluble extract (spectrum F).
94 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

3,000 2,500 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400

A

B

C

D

ABSORBANCE

3,500

WAVELENGTH, IN RECIPROCAL CENTIMETERS

Figure 30. Infrared spectra of dissolved organic carbon (DOC) fractions from water sampled from well PR11 September 19, 1994, at the research basin, 

Montebello Forebay, Los Angeles County, California: ether-extractable acids (spectrum A); hydrophobic fraction, ethyl acetate fraction from silica gel 

(spectrum B); hydrophobic fraction, acetone extract from silica gel (spectrum C); and hydrophobic fraction, 75 percent acetone, 25 percent 2-propanol 

extraction from silica gel (spectrum D).
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 95

The fractions represented by spectra B and C are 

primarily fulvic acids; however, a major peak in fulvic 

acids derived from tannins and lignins at 1,600 to 1,630 

cm-1 is absent. According to Stevenson (1982), this 

peak can be attributed to aromatic C=C stretching 

vibrations, and hydrogen-bonded (by phenol) 

conjugated ketones. This peak is the best indicator in 

IR spectra of polyphenolic aromatics in humic 

substances that are reactive with halides. The fulvicacid fractions in this water sample appear to be 

predominantly aliphatic carboxylic acids with lesser 

amounts of alcohol, ester, and ether functional groups. 

Fractions B and C represent 55 percent of the 

nonextractable hydrophobic fraction and fraction D 

represents 30 percent. The remaining 15 percent is 

distributed among four minor fractions that have 

proteins and pyrimidines in the IR spectra.

 The tentative compound-class assignments 

given to DOC fractions in the reclaimed-water effluent 

were confirmed by IR spectra of various standard 

materials. Spectra of the Suwannee River fulvic acid 

(SRFA) derived from polyphenolic tannin and lignin, 

protein, and a pyrimidine are shown in figure 31. As 

mentioned previously, the polyphenolic indicator peak 

at 1,626 cm-1 for fulvic acid is not significant for humic 

substances fractionated from this reclaimed-water 

effluent (fig. 31, spectra B and C). The defining peak 

for proteins is the amide-2 peak, a broad peak from 

1,520 to 1,560 cm-1, and for pyrimidines, a number of 

medium-intensity peaks from 1,400 to 1,430 cm-1

(fig. 31). Although the peaks indicative of protein and 

pyrimidine structures are not the most intense peaks of 

these substances, these diagnostic peaks occur in 

spectra regions where there are no major interferences 

from other peaks.

For neutral surfactants of the alkylphenol 

polyethoxylate class, the most intense peak of the 

parent surfactants is at 1,111 cm-1, which is the C–O 

stretch of the ether groups in the polyethoxylate chain 

(fig. 32). The loss of most of the polyethoxylate chain 

by microbial degradation produces short-chain 

alkylphenol polyethoxylate (APEO) and APEC 

metabolites, and therefore this ether peak is reduced, 

and an aromatic C=C stretching peak at 1,513 cm-1

becomes the most intense and defining peak of the 

spectrum (fig. 32).

Infrared spectra of a commercial anionic 

detergent formulation of linear alkylbenzene sulfonate 

(LAS) surfactants, the DATS component of this 

surfactant (resistant to complete biodegradation), and a 

sulfophenyl carboxylate (SPC) metabolite of LAS 

degradation are shown in figure 33. The spectra of LAS 

and SPC are characterized by a sharply defined peak 

indicative of 1,4-substituted aromatic rings at 

1,012 cm-1, which is absent in DATS because the 

aromatic ring has a 1,3,4-substitution pattern. The 

intensity ratio of the sulfonic acid peak near 1,040 cm-1

to the 1,012 cm-1 peak is a general indicator of the 

proportions of 1,4-substituted aromatic sulfonates 

(LAS and SPC) and aromatic sulfonates with greater 

ring substitution patterns (DATS, DATS carboxylates, 

sulfonated optical brighteners, and sulfonated textile 

dyes).

Water-quality changes in DOC fractions during 

infiltration of reclaimed water were detected during the 

April 1994 sampling. Shown in figure 34 are HPOn

fraction IR spectra of water samples collected April 5, 

1994, from the research basin (PR12) (spectrum A) and 

from well MLS4 (spectrum B), and a water sample 

collected April 8 from well PR9 (spectrum C). The 

research basin contained large amounts of 

polyethoxylates from nonionic surfactants as indicated 

by peaks at 1,350, 1,110, and 950 cm-1 in spectrum A, 

whereas most of these polyethoxylates are diminished 

by the time the water had infiltrated 4 ft in MLS4 

(spectrum B). Short-chain APEO and APEC 

metabolites of nonionic polyethoxylate surfactants are 

indicated by the peak at 1,513 cm-1 in the 25-ft well 

(PR9) in spectrum C. Conversely, anionic aromatic 

sulfonates are progressively enriched as water 

infiltrates to deeper levels, as indicated by changes in 

the 1,040 and 1,012 cm-1 peaks in spectra A to C. Thus, 

nonionic surfactant polyethoxylates are probably 

metabolized or adsorbed during infiltration, whereas 

anionic aromatic sulfonates (particularly DATS) are 

selectively preserved and enriched in this fraction as 

other components are depleted (Field and others, 

1992a, b).
96 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

4,000 3,000 2,000 1,500 1,000 500 400

Suwannee River fulvic acid

Protein (hair)

Pyrimidine (uracil)

1626.58

1542.10

1418.44

ABSORBANCE

WAVELENGTH, IN RECIPROCAL CENTIMETERS

A

B

C

Figure 31. Infrared spectra of natural fulvic acid, protein, and pyrimidine.
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 97

4,000 3,000 2,000 1,500 1,000 500 400

Alkylphenol polyethoxylate (Triton-X 100)

Nonylphenol –1, 3-ethoxylate)

Nonylphenol-1-ethoxy

carboxylic acid

1512.94

1111.45

951.53

1746.81

1513.12

1513.02

ABSORBANCE

WAVELENGTH, IN RECIPROCAL CENTIMETERS

Figure 32. Infrared spectra of synthetic aromatic sulfonate surfactants and a sulfophenyl carboxylate (SPC) metabolite.
98 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

3,500 2,500 2,000 1, 3,000 2,500 2,000 1, 3,000 800 1,600 1,400 1,200 1,000 00 1,600 1,400 1,200 1,000 800 600 400 00 600 400

LAS (Alconox)

DATS

SPC-8

1043.88

1012.56

1043.72

1038

1012

ABSORBANCE

WAVELENGTH, IN RECIPROCAL CENTIMETERS

Figure 33. Infrared spectra of synthetic alkylphenol polyethoxylate surfactants and certain metabolites. (Refer to figure 24 for compound’s structure.)
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 99

3,000 2,500 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400

A

B

C

ABSORBANCE

3,500

WAVELENGTH, IN RECIPROCAL CENTIMETERS

Figure 34. Infrared spectra of hydrophobic neutral fractions for samples collected April 5, 1994, from the research basin (PR12); April 5 from MLS4; and 

April 8 from well PR9 (spectra A to C, respectively), Montebello Forebay, Los Angeles County, California.
100 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

In the HPIb fraction of these wells, the protein 

component, as measured by the amide-1 and amide-2 

peaks, appears to be depleted, and the pyrimidine 

component, as measured by the 1,410 cm-1 peak, 

appears to be enriched. Both changes in the HPOn

fraction and the HPIb fractions are consistent with 

changes in DOC fractionation patterns discussed 

previously in this report. No readily discerned changes 

in IR spectra were observed in any other fractions.

In the background well 2S/11W-7J1 sampled 

September 21, 1994, trace amounts of APEC were 

detected in the ether-extract fraction, and trace amounts 

of aromatic sulfonates were detected in the 

hydrophobic fractions by IR measurement of indicator 

peaks of these fractions. Apparently, this well is 

slightly contaminated by infiltration of sewage 

wastewater of unknown origin—a suggestion also 

made in Chapter 8 on the basis of large fluctuations in 

hydrophilic and hydrophobic DOC fractions.

In summary, IR analyses of DOC fractions in the 

reclaimed-water effluent revealed a complex mixture of 

natural aliphatic fulvic acid, proteins, and pyrimidines, 

and synthetic APEO, DATS, and LAS surfactants and 

their metabolites that was very different than the DOC 

composition of natural waters. Infiltration of this 

effluent resulted in loss of proteins and parent APEO 

and LAS surfactants, while the proportion of APEC, 

DATS, and LAS metabolites and pyrimidines were 

enriched. The surfactant composition of this reclaimed 

water, and changes during infiltration and transport in 

ground water, is similar to that observed previously by 

Field and others (1992a, b) at Cape Cod, 

Massachusetts.

Ultraviolet/Visible Spectrometry

The ultraviolet/visible (UV/VIS) spectrum of the 

blue dye subfraction isolated from the HPOn fraction of 

well PR9 sampled September 20, 1994, was 

determined on a Perkin-Elmer Lambda 4B UV/VIS 

Spectrophotometer. Most of this subfraction (about 3 

mg) was used for an IR spectrum, but a small residue 

from the freeze-dry vessel was used to generate the 

UV/VIS spectrum shown in figure 35. The sample was 

analyzed in water at pH 6.6 in a 1-cm light-path quartz 

cell. The peak shown in the visible part of the spectrum 

has a spectral maximum at 628 nanometers (nm). The 

IR spectrum showed the presence of aromatic 

sulfonates, but it is unlikely that the IR spectrum 

represented a pure dye. The blue dye has been 

identified by mass spectrometry in a similar reclaimedwater effluent sample from Phoenix, Arizona, as 

erioglaucine (or Brilliant Blue), a water-soluble 

sulfonated triphenylmethane dye that is extensively 

used in food colorings and toilet-cleaning products 

(Rostad and Leenheer, 2000). The blue dye was noted 

in all the reclaimed-water samples and infiltrated 

ground-water samples collected near the research basin 

for both the April and September 1994 samplings. The 

blue dye was not detected in the background-well 

sample (-7J1).
Chapter 9: Characterization of Dissolved Organic Matter by Infrared and Ultraviolet/Visible Spectrometry 101

0

190 400 600 800 900

1.2

1.5

0.3

0.6

0.9

WAVELENGTH, IN NANOMETERS

ABSORBANCE

Figure 35. Ultraviolet/visible (UV/VIS) spectrum of blue dye subfraction isolated from a sample collected September 20, 1994, from well PR9, research 

basin, Montebello Forebay, Los Angeles County, California.
102 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 10: CHARACTERIZATION OF 

DISSOLVED ORGANIC MATTER BY 

NUCLEAR MAGNETIC RESONANCE (NMR) 

SPECTROMETRY 

By Kevin A. Thorn and Steven J. Younger

Dissolved organic matter (DOM) was 

characterized by NMR spectrometric methods 

analogous to those used to characterize colloidal 

organic carbon in Chapter 7.

Sampling

During the April 1994 recharge experiment, 

water samples were collected from PR13 (effluent), 

PR12 (research basin), multilevel sampling ports 

MLS4 and MLS7, and well PR9. During the September 

1994 recharge experiment, water samples were 

collected from PR12 (research basin) and well PR9. 

Water samples were pumped onsite through Balston 

DH (25-μm) and AH (0.3-μm) glass fiber filters, and 

then through AMICON 30,000-molecular-weight 

(0.005 μm) regenerated cellulose membrane filters, 

using tangential flow ultrafiltration (Rostad, 1996; 

Rostad and others, 1998), as was also described in 

Chapter 7. Filtered water samples were chilled on ice 

and transported to the laboratory.

The filtered water samples were then acidified to 

pH 2 using concentrated HCl and passed through a 

two-column array of XAD-8 and XAD-4 resins to 

isolate the major fractions of DOC (Aiken and others, 

1992). Fulvic acids and hydrophobic neutrals were 

eluted from the XAD-8 resins with dilute NaOH and 

100-percent acetonitrile, respectively. Hydrophilic 

acids and hydrophilic neutrals were eluted from the 

XAD-4 resins with dilute NaOH and 100-percent 

acetonitrile, respectively.

The DOC fractions were characterized by liquid 

phase 13C NMR spectrometry; Fourier transform 

infrared spectroscopy (FTIR). (Sufficient sample 

quantities were not available for element and 

molecular-weight analyses.) Liquid-phase 13C NMR 

spectra of DOC fractions were recorded on a Varian 

XL300 NMR spectrometer at a carbon resonant 

frequency of 75.4 MHz using a 10-mm broadband 

probe. Acquisition parameters included a 30,000 Hz 

spectral window, 45-degree pulse angle, 0.2-s 

acquisition time, 1.0-s pulse delay, and continuous 

WALTZ decoupling. These conditions do not eliminate 

differential T1 (spin lattice relaxation time) effects and 

differential nuclear Overhauser enhancement (NOE) 

effects. The peak areas in the liquid phase 13C NMR 

spectra therefore do not represent a quantitative 

distribution of 13C nuclei in the samples.

Results

The continuous decoupled liquid-phase 13C 

NMR spectra of the fulvic-acid fraction from the April 

1994 research-basin sample (PR12) and a sample of 

pristine ground water in Minnesota (Thorn and Aiken, 

1998) are shown for comparison in figure 36. The 

spectrum of the Minnesota ground water has the six 

major broad peaks characteristic of humic substances 

listed below:

.

 • 0–60 ppm Aliphatic carbons (sp3 hybridized) 

bonded primarily to other carbons, 

but also to nitrogen and sulfur

• 60–90 ppm Hetero-aliphatic carbons: sp3

hybridized carbons bonded to 

oxygens, including alcohols, ethers, 

and carbohydrates

• 90–110 ppm Acetal and hemiacetal carbons, 

anomeric carbons of carbohydrates, 

and protonated aromatic carbons

• 110–160 ppm Aromatic and olefinic carbons

• 160–180 ppm Carboxylic acid, ester, and amide 

carbons

• 180–220 ppm Ketone and quinone carbons
Chapter 10: Characterization of Dissolved Organic Matter by Nuclear Magnetic Resonance (NMR) Spectrometry 103

300 250 200 150 100 50 0 –50 –100

PARTS PER MILLION

Research basin

(PR12) fulvic acid

Minnesota (Bemidji)

ground-water fulvic acid

Figure 36. Continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance spectra of April 1994 PR12 fulvic-acid fraction and Minnesota 

ground-water fulvic-acid fraction (Thorn and Aiken, 1998).
104 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

The spectrum of the fulvic-acid fraction in the 

research-basin sample is distinguishable from that of 

the Minnesota fulvic acid in that sharp peaks are 

superimposed over the broad underlying peaks of the 

fulvic-acid material. The sharp peaks in the spectrum 

of the research-basin fulvic acid correspond to LAS 

surfactants and their SPC degradation products 

(sulfophenyl carboxylates), as well as to the APEO 

(alkylphenol polyethoxylate) surfactants and their 

APEC (alkylphenol polyethoxy carboxylate) 

degradation products, and to dialkyltetraline sulfonates 

(DATS). Some of the major assignments for these 

surfactants and surfactant degradation products are 

illustrated in figure 37. For example, the peaks from 60 

to 70 ppm correspond to the polyethoxylate carbons of 

APEOs and APECs. The peaks at approximately 

128 ppm correspond to the protonated aromatic 

carbons in the benzene rings of the SPCs, APECs, 

DATS, and the corresponding degradation products. 

The peaks at approximately 115 ppm correspond to the 

protonated aromatic carbons ortho to the 

polyethoxylate chains on the benzene rings of the 

APECs. The peak at 142 ppm corresponds to the 

aromatic carbons bonded to the sulfonate groups in the 

benzene rings of LAS and SPCs. More detailed 

interpretations of the surfactant spectra are given by 

Thurman and others (1987) and Field and others 

(1992c). The 13C NMR spectrum of the fulvic-acid 

fraction isolated from PR9 during the April experiment 

(fig. 38) is virtually identical to the research-basin 

spectrum. Thus, there is no discernible qualitative 

attenuation of the constituents that co-isolate in the 

fulvic-acid fraction on XAD-8 resin as the reclaimed 

water infiltrates to a depth of 25 ft. [Shortening of 

ethoxylate chain lengths in the APEO and APEC 

materials recovered in the acetonitrile eluates from the 

XAD-8 resins between the research-basin water (PR12) 

and the MLS4 water was observed; spectra not shown.] 

The results observed in the spectra of the fulvic-acid 

fractions from the April experiment are replicated in 

the September experiment (figs. 39, 40). Again, the 

LAS, surfactants, SPCs, APEOs, and APECs persist in 

the fulvic acid fraction as the pond water infiltrates to a 

depth of 25 ft.

The detection of surfactants and surfactant 

degradation products in the fulvic-acid fractions is 

consistent with the IR and GC/MS analyses presented 

in Chapters 9 and 12.
Chapter 10: Characterization of Dissolved Organic Matter by Nuclear Magnetic Resonance (NMR) Spectrometry 105

300 250 200 150 100 50 0 –50 –90

PARTS PER MILLION

D

B

A

C

D

C

SO Na 3

 

H C3 2 n CH3 (CH ) CH (CH )2 m

n m  7  11

LAS surfactant

B

A

R O [CH CH ] 2 2n CH2CH O2

Alkylphenol polyethoxylates (APEOs)

R = nonyl n = 0 – 20

Figure 37. Continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance spectrum of April 1994 PR12 fulvic-acid fraction showing chemical 

shift assignments of surfactants.
106 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

300 250 200 150 100 50 0 -50 -100

PARTS PER MILLION

Figure 38. Continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance spectrum of April 1994 PR9 fulvic-acid fraction.
Chapter 10: Characterization of Dissolved Organic Matter by Nuclear Magnetic Resonance (NMR) Spectrometry 107

300 250 200 150 100 50 0 –50 –100

PARTS PER MILLION

Figure 39. Continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance spectrum of September 1994 PR12 fulvic-acid fraction.
108 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

300 250 200 150 100 50 0 –50 –100

PARTS PER MILLION

Figure 40. Continuous decoupled liquid-phase carbon-13 nuclear magnetic resonance spectrum of September 1994 PR9 fulvic-acid fraction.
Chapter 11: Distributions of Halogenated Organic Compounds 109

CHAPTER 11: DISTRIBUTIONS OF 

HALOGENATED ORGANIC COMPOUNDS 

By Colleen E. Rostad and Ronald E. Rathbun

Understanding the dominant geochemical factors 

involved in degradation or alteration of dissolved 

organic carbon (DOC) at soil-aquifer treatment sites is 

critical to reliably predict the potential for DOC 

degradation, migration, and fate. One water-quality 

characteristic of concern is total organic halogen or 

halide (TOX)—a collective term encompassing 

halogenated organic compounds in the water, many of 

which are toxic, carcinogenic, or mutagenic, and 

includes those compounds that comprise the 

trihalomethanes (THMs). These contaminants result 

from the disinfection of water using chlorine and are 

formed by reaction of the chlorine with the DOC. The 

nature and the extent of the TOX and THMs so 

generated vary with the nature and reactivity of the 

DOC. Initial studies indicated that THMs and DOC 

that infiltrate into an aquifer decrease downgradient, 

whereas TOX is unaffected by aquifer passage 

(Roberts, and others, 1982). In more-recent studies, 

TOX decreased concurrently with DOC during soilaquifer treatment (Wilson and others, 1995). Factors 

that affect the fate of TOX and THM during artificial 

recharge with reclaimed wastewater are complex. The 

research basin was sampled in April and September 

1994 to determine whether TOX and THM are 

attenuated beneath the research basin under different 

hydraulic conditions. Samples were taken a few days 

after delivery of recycled water to the research basin 

commenced, and thus “steady-state” conditions had 

been established.

Methods

Samples collected in April and September 1994 

at the research basin were analyzed for THMs by 

solvent-extraction procedure Standard Method 6232B 

(AWWA, 1992) or the equivalent U.S. Environmental 

Protection Agency (U.S. EPA) Method 501.2 (CFR, 

1994), with slight modifications. A trace of sodium 

sulfite added to the 40-mL amber glass vial in which 

the samples were collected scavenged any free chlorine 

present and eliminated further THM formation. 

Samples were collected with no head-space and chilled 

or refrigerated until extracted. Until analysis, sample 

vials were stored, at 4oC, upside down to preclude 

losses through the septum cap during storage. Sample 

extractions using pentane were done directly in the 

sample vials to avoid sample transfer of volatile 

constituents. The extraction step consisted of removing 

and discarding 4.5 mL of sample using an adjustable 

pipetter, adding 4.0 mL of ultra-high-purity THMgrade pentane with a Class A pipet, and shaking the 

vial for 1.5 minutes. Vials were weighed at each step to 

determine the precise amounts of sample removed and 

pentane added. Pentane extracts were analyzed by gas 

chromatography with electron-capture detection

(GC-ECD). The extracts were injected splitless at 

200oC on a 12-m, 0.2-mm i.d., cross-linked surfacebonded 1-percent dimethylpolysiloxane capillary GC 

column, at 30oC for 8 minutes. Standard samples 

covering the expected range of sample concentrations 

were prepared by injecting microliter quantities of 

primary standards into the background-well 

(2S/11W-7J1) water contained in the vials. 

Background-well water was used as the standard 

matrix to eliminate effects of the water chemistry on 

the efficiency of the extraction procedure. Standard 

samples were then treated in exactly the same way as 

were the study samples. 

Silver-membrane field-filtered samples were 

analyzed for TOX by Standard Method 5320 (AWWA, 

1992) as described briefly herein. Samples were 

collected into 125-mL amber glass bottles, to which a 

small amount of sodium sulfite preservative had been 

added, and were acidified to pH 2 using reagent-grade 

nitric acid when received in the laboratory. The TOX 

compounds were adsorbed from the water sample onto 

granular activated carbon packed in glass columns. 

Adsorption occurred on two columns placed in series. 

The columns were washed with 2 mL of 0.08 M 

potassium nitrate solution to remove inorganic halides. 

The granular carbon was transferred to a quartz sample 

boat in the Dohrmann DX-20A TOX analyzer with an 

AD-3 adsorption module and analyzed. Samples were 

analyzed in duplicate to compensate for the inherent 

variability of the analytical procedure. 
110 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Results

Concentrations of the THM and TOX in samples 

collected near the research basin are shown for April 

1994 in table 21 and for September 1994 in table 22. 

When the research basin was sampled in April 1994, 

THM concentrations ranged from greater than 15 μg/L 

to non-detectable (<0.01 μg/L) levels. Concentrations 

were highest in the effluent (PR13) and ponded water 

in the research basin (PR12) and were lower beneath 

the research basin, as shown in figure 41. The decrease 

could be due largely to dilution by antecedent soil 

moisture much lower in THM and TOX as it was partly 

displaced by the recycled water percolating downward 

from the research basin. The high THM concentrations 

found in the effluent and research basin were markedly 

reduced (to 3 μg/L) in the shallowest multilevel 

sampler at a depth of 4 ft. The low THM concentration 

at 4 ft then appears to increase (to almost 10 μg/L) with 

increasing depth to 25 ft (PR9 sample on April 7). 

Concentrations were below detection at 50 ft below the 

research-basin floor (PR8) and also next to the basin at 

a depth of 25 ft below the basin floor (PR11). The fact 

that THM concentrations in the recycled water appear 

to decrease soon after infiltration and then increase 

again with increasing depth suggests possible 

formation of compounds during downward percolation. 

Further support for this hypothesis is provided by the 

observation that THM concentration rises from a nondetectable level on April 5 to about 9 μg/L on April 7 

in PR9, presumably as newly recycled water reaches 

this depth. Caution is advised, however, as the amount 

of data is scant and even the DOC concentration in 

MLS4 seems to be anomalously low. The pattern for 

TOX is generally the same as that of THM, although 

TOX concentrations are higher (fig. 41).

The THM concentration of about 17 μg/L for 

recycled water in the research basin during the 

September 1994 recharge event was slightly higher 

than the concentration during the April 1994 

experiment (compare data in tables 21 and 22). For 

comparison with wastewater from other cities, THM 

concentrations, in micrograms per liter, in wastewater 

after secondary biological treatment were 1.5 for 

Washington, D.C., 4.1 in Phoenix, Arizona, 

2.7 in Denver, Colorado, and 13.3 in Palo Alto, 

California (McCarty, 1990). Although higher than in 

these cities, THM concentrations in the research basin 

were still much lower than concentrations in most 

chlorinated drinking water. Median values, in 

micrograms per liter, of total THMs in drinking water 

from 35 treatment facilities varied seasonally and were 

34 in spring, 44 in summer, 40 in autumn, and 30 in 

winter (Krasner and others, 1989). A much broader 

survey reported similar median THM concentrations 

from 727 water-supply utilities nationwide at 40 in 

spring, 44 in summer, 36 in autumn and 30 in winter 

(McGuire and Meadow, 1988). 

The pattern of both THM and TOX 

concentrations was similar in April and September with 

one important difference—elevated concentrations 

were observed deeper (compare data from 50 ft in

figs. 41 and 42) and farther offsite in September 1994. 

This could be a consequence of differing hydraulic 

conditions, as described in Chapter 3, “Geologic and 

Hydrologic Setting,” allowing the contaminants to 

migrate farther when the water table was much lower in 

September. However, it could also be caused by 

seasonal differences in the way stormwater and 

recycled water are supplied to the adjacent large 

spreading grounds. Antecedent water beneath the clay 

lens in April 1994 would be expected to have been 

replaced by a greater percentage of stormwater 

following the wet season, whereas the deep water in 

September could have been flushed by a greater 

percentage of recycled water recharged during the 

summer dry season. 

Concentrations of TOX in the effluent (PR13) 

and in the research basin (PR12) during both sampling 

times were generally a little higher than is typical of 

concentrations in wastewater from other places. 

Concentrations in wastewater after secondary 

biological treatment ranged from 85 μg/L in 

Washington, D.C., 87 μg/L in Phoenix, Arizona, 

131 μg/L in Orange County, California, to 192 μg/L in 

Palo Alto, California (McCarty, 1990). The TOX 

concentrations in finished drinking water from five 

selected water utilities in 1983–84 were 152, 298, 319, 

460, and 549 μg/L, respectively (Singer and Chang, 

1989)—notably higher than TOX concentrations 

typical of wastewater. As expected, TOX 

concentrations are much lower in surface water than in 

treated wastewater, averaging 15.2 μg/L for the 

Mississippi River, 8.64 μg/L for the Missouri River, 

and 12.14 μg/L for the Ohio River (Rathbun and 

Bishop, 1993, 1994; Rathbun, 1995).
Chapter 11: Distributions of Halogenated Organic Compounds 111

Table 21. Concentrations of trihalomethanes (THMs), total organic halides (TOX), and dissolved organic carbon (DOC), and ratios of THM/TOX and 

TOX/DOC, in samples collected at the research station, Montebello Forebay, Los Angeles County, California, April 7, 1994 (except where noted)

[mg/L, milligrams per liter; μg/L, micrograms per liter; <, less than; —, no data]

Sample THM

(μg/L)

TOX

(μg/L)

DOC

(mg/L)

THM 

as percent 

of TOX

TOX 

as percent 

of DOC

MLS20 5.95 94 4.35 6.33 2.16

MLS15 9.07 136 5.88 6.65 2.32

MLS10 9.74 126 5.76 7.76 2.18

MLS7 5.61 103 4.12 5.46 2.49

MLS4 2.72 46 3.59 5.87 1.29

PR8 <.01 29 2.26 .01 1.28

PR9 (April 5) <.01 48 2.46 .01 1.96

PR9 (April 7) 9.08 113 4.47 8.04 2.53

PR10 — 24 2.14 — 1.13

PR11 <.01 20 2.51 .02 .80

PR12 15.43 175 9.18 8.84 1.90

PR13 14.06 224 9.69 6.27 2.31

2S/11W-18P1 — 73 3.61 — 2.02

2S/11W-19C1 5.06 58 3.47 8.75 1.67

2S/11W-7J1 <.01 — 1.56 — —

Deionized water blank — .20 — — —

Balston blank — 1.76 .10 — 1.76

Table 22. Concentrations of trihalomethanes (THMs), total organic halogens (TOX), and dissolved organic carbon (DOC), and ratios of THM/TOX and 

TOX/DOC, in samples collected at the research basin, Montebello Forebay, Los Angeles County, California, September 1994

[mg/L, milligrams per liter; μg/L, micrograms per liter; —, no data]

Sample THM

(μg/L)

TOX

(μg/L)

DOC

(mg/L)

THM 

as percent 

of TOX

TOX 

as percent 

of DOC

MLS15 5.89 115 5.30 5.12 2.17

PR8 9.23 87 — 10.63 —

PR9 7.51 131 5.50 5.74 2.38

PR10 6.30 73 — 8.57 —

PR11 9.82 110 5.40 8.90 2.04

PR12 17.24 156 8.30 11.06 1.88

WP5 4.12 74 4.10 5.57 1.81

2S/11W-18P1 .53 36 — 1.47 —

2S/11W-19C1 .94 32 — 2.88 —

2S/11W-7J1 2.16 19 1.90 11.54 .98
112 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

0

10

20

30

40

50

60

CONCENTRATION, IN MICROGRAMS PER LITER

0 20 40 60 80 100 120 140 160 180 200

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

TOX

THM

Figure 41. Concentrations of trihalomenthane (THM) and total organic halides (TOX) for selected samples collected in April 1994 at the research basin, 

Montebello Forebay, Los Angeles County, California.
Chapter 11: Distributions of Halogenated Organic Compounds 113

0

10

20

30

40

50

60

CONCENTRATION, IN MICROGRAMS PER LITER

0 20 40 60 80 100 120 140 160 180 200

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

TOX

THM

Figure 42. Concentrations of trihalomenthane (THM) and total organic halides (TOX) for selected samples collected in September 1994 at the research 

basin, Montebello Forebay, Los Angeles County, California.
114 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Mass ratios for TOX to THM of 3 to 10, 

depending on treatment conditions, have been found in 

water from various sources (Singer and Chang, 1989). 

In surface water treated for drinking water, the TOX to 

THM ratio averaged about 3.4 (Singer and Chang, 

1989). In the study area, the ratio ranged from 11 to 18 

in April 1994, and from 9 to 20 in September 1994—if 

ratios in which THM concentrations near limits of 

detection are eliminated (calculated from data tables 21 

and 22). These high TOX to THM ratios indicate that 

complex halogenated compounds, rather than THM, 

are a large component of the complex halogenated 

compounds at this site. 

Low levels of THMs at some of the sample sites 

produce wide variation in the TOX to THM ratio, and 

the percentage of THM in the TOX was compared for 

each site (listed for April 1994 in table 21 and for 

September 1994 in table 22). Changes in this 

percentage during infiltration may indicate preferential 

degradation or sorption of either THM or TOX during 

recharge. In April (fig. 43) and in September (table 22), 

the percentage of THM in the TOX ranged from 5 to 9 

and did not show any discernible vertical trend between 

5 and 25 ft beneath the basin floor. The percentage of 

THM in the TOX was a little higher in the research 

basin than beneath the research basin, suggesting 

preferential removal of the simpler THM compounds, 

or preferential generation of the more complex TOX 

compounds, during infiltration. The percentage of 

THM in the TOX at 50 ft below the research basin 

(PR8 and PR10) was near zero in April 1994 but high 

in September 1994. Since recycled water from the 

recharge experiments in the research basin is known 

not to reach this depth, this seasonal variation must be 

indicative of larger regional factors, as noted earlier. It 

is likely that the ground water at this depth contains a 

high proportion of the prior winter’s stormwater in 

April, whereas in September it contains a high 

proportion of recycled water from the spreading 

grounds or unlined reaches of the San Gabriel River 

following several months of negligible rainfall.

The percentage of TOX with respect to DOC 

measured here, at about 1 to 2 percent, is much lower 

than percentages for formation potentials reported in 

surface water from other areas (Rathbun and Bishop, 

1993, 1994; Rathbun, 1995) In order to determine 

whether TOX was changing with respect to DOC 

during recharge, the TOX as a percent of DOC was 

evaluated from data for April 1994 in table 21 (and 

fig. 43) and for September 1994 in table 22. The data 

do not provide clear evidence for preferential removal 

or enrichment in TOX with respect to DOC. Although 

the proportion as TOX is lower in the 50-foot wells 

(PR8 and PR10) than at shallower depths for the 

samples collected in April, as noted already, this deeper 

ground water may have contained a high proportion of 

antecedent stormwater at that time. No samples from 

either well were obtained in September, when more 

wastewater and less stormwater might have been 

present as discussed above.
Chapter 11: Distributions of Halogenated Organic Compounds 115

THM AND TOX, AS PERCENT OF TOX AND DOC, RESPECTIVELY

DEPTH BELOW BOTTOM OF RESEARCH BASIN, IN FEET

0246 8 10

0

10

20

30

40

50

60

TOX/DOC THM/TOX

Research basin (PR12)

Ground water

Figure 43. Trihalomethane to total organic halide ratios (THM/TOX) and total organic halide to dissolved organic carbon ratios (TOX/DOC) for selected 

samples collected in April 1994 at the research basin, Montebello Forebay, Los Angeles County, California.
116 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

CHAPTER 12: SPECIFIC ORGANIC 

CONTAMINANTS 

By Larry B. Barber and Colleen E. Rostad

Anionic surfactants and their metabolites are a 

major group of dissolved organic contaminants found 

in reclaimed water (Barber, 1992; Swisher, 1987). 

Caffeine has also been found to be a useful indicator to 

distinguish domestic-wastewater inputs from 

industrial-wastewater inputs elsewhere (Barber and 

others, 1995 a, b). Therefore, water samples collected 

during the April and September 1994 recharge 

experiments were analyzed for anionic aromatic 

sulfonate surfactants, certain aromatic sulfonate 

metabolites, and caffeine. Samples of reclaimed water 

also were analyzed for specific volatile organic 

compounds.

Sampling

Samples for specific compound analyses were 

collected during two sampling trips: April 4–7 and 

September 19–22, 1994. Treated-wastewater effluent 

and ground water were sampled for methylene blue 

active substances (MBAS), linear alkylbenzene 

sulfonate (LAS), caffeine, and volatile organic 

compound (VOC) analyses. Raw water samples were 

collected without head-space in 40-mL amber glass 

bottles for VOC analyses. Samples for MBAS, LAS, 

and caffeine analyses were pressure-filtered through 

1-μm glass-fiber filters and preserved with 2-percent 

formalin. All samples were stored in the dark at 4oC 

until analyzed.

Analytical Methods

Methylene Blue Active Substances

Methylene blue active substance (MBAS) 

analysis is a measure of total anionic surfactants, and 

includes linear- and branch-chained alkylbenzene 

sulfonic acids (LAS and ABS), sulfophenyl carboxylic 

acid (SPC) degradation products of LAS and ABS, 

dialkyltetralin sulfonates and dialkylindane sulfonates 

(DATS), which are impurities in LAS and ABS 

formulations, alkylsulfates, and other natural and 

synthetic strong-acid hydrophobic compounds. Filtered 

formalin-preserved samples were analyzed for MBAS 

using a miniaturized version of the method described 

by Wershaw and others (1983). This method involves 

(1) acidifying a 5-mL water sample to pH <2 using 

sulfuric acid, (2) adding an aqueous methylene blue 

solution to form an ion pair with anionic compounds in 

the acidified water sample, and (3) extracting the 

methylene blue ion pair into chloroform. The amount 

of extracted anionic surfactant is measured by 

absorbance at 635 nm on a UV/VIS spectrophotometer. 

The acidification step removes interferences from weak 

organic acids that become protonated, and the 

chloroform extraction isolates the hydrophobic organic 

ion pairs and removes interferences from inorganic 

anions. Quantification was based on a 4-point standard 

curve. Each set of samples included a distilled water 

blank and from one to three quality-assurance 

standards. Replicate analysis was performed on 

selected samples. The detection limit for this method is 

about 20 μg/L.

Anionic Surfactants 

Samples collected in April 1994 were analyzed 

for LAS and related compounds using a modification 

of the solid-phase extraction (SPE), derivatization, gas 

chromatography/mass spectrometry (GC/MS) method 

of Trehy and others (1990). Details of this method are 

given by Barber and others (1995a, b). The SPE 

isolation was performed by a Waters Millilab 1A 

robotics workstation. Octadecyl surface-modifiedsilica (C18) SepPak cartridges (1g) were used for 

reverse-phase isolation.

The C18 cartridges were conditioned with 

methanol prior to processing the 1-L samples. The 

samples were passed through the cartridges at a flow 

rate of 20 mL/min. The C18 cartridge was eluted with 

5 mL of acetonitrile followed by 5 mL of methylene 

chloride, and the combined eluant was evaporated to 

dryness under a stream of N2. The LAS in the C18

extracts was derivatized by reacting the residue with 

phosphorous pentachloride followed by 

trifluoroethanol to form the trifluoroethyl esters of 

LAS.
Chapter 12: Specific Organic Contaminants 117

The derivatized extracts were analyzed by 

electron-impact GC/MS using a Hewlett Packard 

5890 GC with a 5970 Mass Selective Detector in both 

the full-scan and selected-ion monitoring (SIM) modes. 

The conditions for the analysis are: column, Hewlett 

Packard Ultra II, 25 m by 0.2-mm i.d., 20-μm film 

thickness; carrier gas, ultra-high-purity helium, 

27 cm/s; source temperature, 250oC; source pressure, 

1 x 10-5 torr; ionization energy, 70 electron volts; scan 

range, 45 to 550 atomic mass unit (AMU); scan time, 

1 scan/s; splitless mode, purge valve on at 0.75 min; 

injector temperature, 280oC; MS interface temperature, 

250oC; initial oven temperature, 110oC; initial hold 

time, 1 min; ramp rate, 8oC/min; final temperature, 

300oC; final hold time, 5 min. Selected ion-monitoring 

data were collected for the molecular ions [M+] of the 

trifluoroethyl ester derivatives of the individual LAS 

homologs (m/z 352 for C8, 366 for C9, 380 for C10, 

394 for C11, 408 for C12, 422 for C13, and 436 for C14) 

and for their base peaks (m/z 253 and 267).

Several quality-assurance and quantitation 

standards were used, including: C10–C14 LAS (Vista 

Chemical), C8-LAS (Aldrich), and C9-LAS (Procter 

and Gamble Company). The C9-LAS surrogate 

standard was added to the aqueous sample prior to SPE 

isolation to evaluate the whole-method recovery, and 

the C8-LAS was added to the extract after isolation to 

evaluate derivatization. The C10–C14 LAS standard 

was spiked into distilled water and processed through 

the entire procedure in the same manner as were field 

samples. Quantitation of LAS was based on the 

C9-LAS molecular-ion peak area (SIM mode) and the 

peak areas of the individual isomers and homologs of 

C10–C14 LAS. The detection limit for individual 

homologs that comprise the total LAS was about 

0.1 μg/L.

Samples collected in September were analyzed 

for LAS by a different method (Field and others, 

1992c, 1994). Additional details of the method are 

described by Barber and others (1999). This method 

involves injection-port derivatization using 

tetrabutylammonium hydrogen sulfate (TBA) in 

chloroform. Water samples (1 L) were isolated on 

C18 silica cartridges using the Waters Millilab 1A 

robotics system after ionic-strength adjustment using 

sodium chloride. After isolation, the cartridges were 

eluted with TBA/chloroform, dried over sodium 

sulfate, and concentrated to a final volume of 200 μL.

The extracts were analyzed by GC/MS using the 

same conditions described above with the following 

changes: split mode, 10:1 split ratio; injection-port 

temperature, 300oC; initial oven temperature, 110oC; 

initial time, 0 min; ramp rate, 20oC/min to 200oC 

followed by 6oC/min to 300oC; final hold time, 5 min. 

Selected ion-monitoring data were collected for the 

[M+−55] ions (molecular ion minus loss of the butyl 

functional group) of the butylated esters of the 

individual homologs (m/z 271 for C8, 285 for C9, 

299 for C10, 313 for C11, 327 for C12, 341 for C13, and 

355 for C14) and for their base peaks (m/z 91, 171, and 

185). Concentrations were calculated relative to the 

C9-LAS surrogate standard using response factors 

determined from a 4-point calibration curve. The 

detection limit for this method was about 0.1 μg/L for 

each homolog.

Caffeine

Samples were analyzed for caffeine by SPE 

sorption, followed by GC/MS analysis, as described by 

Barber and others (1995 a, b). Caffeine was extracted 

from 1 L of formalin-preserved water samples using 

C18 SepPak cartridges and the Millilab 1A workstation. 

The water samples were spiked with C13 caffeine 

(Cambridge Isotopes), passed through the C18

cartridge, and eluted with ethyl acetate or 

TBA/chloroform. The switch was made from ethyl 

acetate to TBA/chloroform to allow the simultaneous 

measurement of caffeine and LAS. The recovery of 

caffeine is about the same for both eluting solvents. 

The solvent extract is dried over sodium sulfate and its 

volume is reduced to 100 μL.

The extracts were analyzed in the full-scan and 

SIM modes by GC/MS using the splitless conditions 

described above, with the following changes: injectionport temperature, 280oC; initial oven temperature, 

60oC; initial time, 1 min; ramp rate, 8oC/min; final 

temperature, 300oC; final hold time, 0 min. Selected 

ion-monitoring data were collected for the [M+] of 

caffeine and the C13 caffeine surrogate standard 

(m/z 194 and 197, respectively) and for the base peaks 

of the compounds (m/z 109 and 180, respectively). 

Quantitation of caffeine was based on the molecularion peak area of the C13 caffeine surrogate standard 

and response factors determined from a 4-point 

calibration curve, or from the molecular-ion peak area 

of caffeine and a 4-point external standard calibration 

curve. The detection limit for this method is about 

0.01 μg/L. 
118 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Volatile Organic Compounds

In order to ascertain the potential for specific 

volatile organic compound (VOC) input to the ground 

water due to recharge using reclaimed water, a sample 

from the research basin (PR12) taken in September 

1994 was analyzed for VOCs by purge-and-trap 

capillary GC/MS (Rose and Schroeder, 1995), which is 

similar to U.S. EPA Method 524.2 (Eichelburger and 

Budde, 1989). 

Results

April 1994 Sampling

Methylene Blue Active Substances

Methylene blue active substances (MBAS) were 

measured as an indicator of anionic surfactants 

(table 23). Concentrations ranged from 840 μg/L in the 

sewage effluent (PR13) to 230 μg/L in the 50-foot well 

(PR8). There was a 46-percent decrease in MBAS 

concentration between the effluent (PR13) and the 

research basin (PR12), followed by an additional 

51-percent decrease during the first 4 ft of infiltration, 

below which the variation in MBAS concentrations 

remains within analytical precision in the multilevel 

sampler (MLS) samples. Concentrations of MBAS in 

all of the samples beneath the research basin to a depth 

of 25 ft were elevated with respect to concentrations in 

samples from 50 ft (PR8 and PR10).

Linear Alkylbenzene Sulfonate 

Specific anionic surfactant (LAS) was measured 

and concentrations are given in table 23. Linear 

alkylbenzene sulfonate is a complex mixture consisting 

of 26 separate isomers and homologs. Each isomer has 

a different rate of biodegradation. The process of 

biodegradation results in the selective removal of the 

more biodegradable components (Tabor and Barber, 

1996).

The isomeric composition of the LAS in the 

effluent and ground water beneath the research basin 

was enriched in the more biologically resistant internal 

isomers. The concentration of LAS (table 23, fig. 44) 

accounts for only 5 percent of the total MBAS response 

in the effluent (PR13) and for even less in the groundwater samples. In addition to LAS, MBAS also is a 

partial measure of the impurities and metabolites of 

LAS (Field and Leenheer, 1988), which are not 

included in the reported LAS values. Results of the 

GC/MS analysis indicate the presence of SPC and 

DATS in the effluent and ground water. These 

compounds have been shown to be recalcitrant to 

biodegradation and thus are preferentially preserved 

(Field and others, 1992a, b). However, these 

compounds were not quantified. The MBAS method 

also is susceptible to positive interferences from 

elevated nitrate and chloride concentrations (Burkhardt 

and others, 1995), which are an additional source of 

error.

The concentration of total LAS decreased by 

83 percent between the effluent (PR13) and the 

research basin (PR12), a greater removal than was 

observed for MBAS. Although there is considerable 

scatter in the data (perhaps because differences in the 

time of sampling wherein steady-state conditions had 

not yet been established at all depths), additional 

removal of LAS with increasing depth is apparent. 

With the exception of the second sample, collected at 

PR9 on April 7, after recycled water likely had reached 

this depth, no LAS was detected below 20 ft.

Caffeine

 Caffeine was measured in the research basin 

(PR12) and at a few depths beneath the research basin 

(table 23). Concentrations for all samples were near the 

detection limit (0.05 μg/L), and there was no apparent 

trend with depth. Low caffeine concentration in the 

recycled water could be an indication of the 

effectiveness of treatment by the wastewater-treatment 

plants in this area.

September 1994 Sampling

Linear Alkylbenzene Sulfonate

Concentrations of LAS for the September 1994 

sampling are given in table 24. Concentrations in the 

effluent (PR13), which were determined by the method 

of Field and others (1992c, 1994), were about the same 

in April (40.6 μg/L) and September (36.6 μg/L). In 

contrast to the April sampling, the results from 

September show a much lower removal rate with 

increasing depth. During both recharge events, LAS 

was detected in the 25-foot well (PR9), and the LAS 

mixture was enriched in the more biologically resistant 

internal isomers.
Chapter 12: Specific Organic Contaminants 119

DEPTH BELOW RESEARCH BASIN, IN FEET

246 8 10 12 14 16 18 20

MICROGRAMS PER LITER

100

0

0

200

300

400

500

600

700

800

900

LAS x 10

MBAS

Effluent

(PR13)

Effluent (PR13)

Research basin (PR12)

Research basin (PR12)

Figure 44. Attenuation of anionic surfactant concentrations (LAS and MBAS) with depth below research basin during infiltration of reclaimed water, April 

1994, Montebello Forebay, Los Angeles County, California.
120 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Caffeine 

Results from caffeine analysis (table 24) indicate 

that concentrations in all samples were near the 

detection limit (0.05 μg/L), as they were in April. 

These results confirm that caffeine concentrations are 

too low for it to be a useful tracer of recycled water at 

this site.

Volatile Organic Compounds

Twenty-two of seventy-seven volatile target 

compounds measured were detected in a sample of 

recycled water from the research basin (PR12). 

Concentrations of the compounds that were detected 

are given in table 25. Compounds that were not 

detected are listed in table 26. The sample was not 

spiked with surrogates in the field when collected. In 

addition, the sample was preserved by addition of 

sodium sulfite, rather than ascorbic acid and 

hydrochloric acid typically used in the USGS National 

Water Quality Laboratory (NWQL) in Denver (Rose 

and Schroeder, 1995). The sample was analyzed 

slightly beyond the typical 14-day holding time. 

Concentrations, therefore, should be considered 

minimum values and could explain why the summed 

concentration for individual compounds at about 

9 μg/L is less than the THM concentration of 17 μg/L 

reported using methods described in the previous 

chapter (table 22). In spite of these limitations, the 

enhanced detection limits of the NWQL, where the 

analysis was done, provided detections as low as 

0.02 μg/L.

Most of the compounds detected are disinfection 

byproducts or common industrial solvents. None of the 

detected compounds were near Action or Maximum 

Contaminant Levels (Landsman and Fisher, 1991). For 

methylene chloride, the California Department of 

Health Services Action Level is 40 μg/L; concentration 

in the research basin was only 1 μg/L. The Maximum 

Contaminant Level under the current Drinking Water 

Standard for methylene chloride is 5 μg/L (U.S. 

Environmental Protection Agency, 1996). Toluene was 

found in the research basin at a concentration of only 

0.06 μg/L. The Action Level for toluene is 100 μg/L, 

and the California Department of Health Services 

Detection Limit for purposes of reporting is 

10.0 μg/L. The Maximum Contaminant Level under 

the current Drinking Water Standard for toluene is 

1,000 μg/L (U.S. Environmental Protection Agency, 

1996).

Table 23. Concentrations of methylene blue active substances (MBAS), 

linear alkylbenzene sulfonate (LAS), and caffeine for samples collected at 

the research basin, Montebello Forebay, Los Angeles County, California, 

April 1994

[μg/L, micrograms per liter; <, less than; —, not analyzed]

Sample MBAS

(μg/L)

LAS

(μg/L)

Caffeine

(μg/L)

PR13 840 40.6 —

PR12 450 7.1 0.05

MLS4 220 .5 —

MLS7 260 1.4 .11

MLS10 350 5.2 .07

MLS15 370 4.4 —

MLS20 330 1.4 .05

PR11 230 <.5 —

PR10 200 <.5 —

PR9 (April 5) 220 <.5 —

PR9 (April 7) 320 3.6 —

PR8 230 <.5 —

2S/11W-19C1 280 — —

2S/11W-18P1 280 — —

2S/11W-7J1S — — —

Field blank 10 <.5 —

Table 24. Concentrations of methylene blue active substances (MBAS), 

linear alkylbenzene sulfonate (LAS), and caffeine concentrations for 

samples collected at the research basin, Montebello Forebay, Los Angeles 

County, California, September 1994 

[μg/L, micrograms per liter; <, less than; —, not analyzed]

Sample MBAS

(μg/L)

LAS

(μg/L)

Caffeine

(μg/L)

PR13 — 36.6 0.08

MLS15 — 21.7 .08

PR9 — 9.5 .08

PR11 — <1.0 .08

WP5 — 5.1 <.05

2S/11W-7J1S — 1.0 <.05
Chapter 12: Specific Organic Contaminants 121

Table 25. Concentrations of volatile organic compounds (VOCs) identified 

by purge and trap gas chromatography-mass spectrometry (GC/MS) in 

recycled water from the research basin (PR12), Montebello Forebay, Los 

Angeles County, September 1994

[Compounds listed in order of GC retention time; μg/L, micrograms per 

liter]

Compound Concentration

(μg/L)

Chloromethane 0.04

Trichlorofluoromethane .02

Methylene chloride 1.01

Methyl-t-butyl ether .51

1,1-Dichloroethane .10

Bromochloromethane .08

Chloroform 6.10

1,1,1-Trichloroethane 6.51

Carbon tetrachloride .01

1,2-Dichloroethane .05

Trichloroethene .03

Dibromomethane .08

Bromodichloromethane 1.93

Toluene .06

Tetrachloroethene 1.51

Dibromochloromethane .72

Ethylbenzene .02

m- and p-Xylene .01

o-Xylene .03

Bromoform .13

1,4-Dichlorobenzene .62

1,2-Dichlorobenzene .09
122 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Table 26. Volatile organic compounds (VOCs) not detected by purge and trap gas chromatography-mass spectrometry (GC/MS) in recycled water from the 

research basin (PR12), Montebello Forebay, Los Angeles County, California, September 1994

[Compounds listed in order of GC retention time]

VOCs

Dichlorodifluoromethane 2-Chlorotoluene

Vinyl chloride 4-Chlorotoluene

Bromomethane 1,3,5-Trimethylbenzene

Chloroethane 2-Ethyl toluene

Acrolein tert-Butylbenzene

1,1-Dichloroethene 1,2,4-Trimethylbenzene

1,1,2-Trichloro-l,2,2-trifluoroethane sec-Butylbenzene

Acrylonitrile 1,3-Dichlorobenzene

trans-1,2-Dichloroethene p-Isopropyltoluene

2,2-Dichloropropane 1,2,3-Trimethylbenzene

cis-1,2-Dichloroethene n-Butylbenzene

1,1-Dichloropropene 1,2-Dibromo-3-chloropropane

Benzene 1,2,3,4-Tetramethylbenzene

1,2-Dichloropropane 1,2,3,5-Tetramethylbenzene

2-Chloroethylvinylether 1,2,4-Trichlorobenzene

cis-1,3-Dichloropropene Hexachlorobutadiene

trans-1,3-Dichloropropene Naphthalene

1,1,2-Trichloroethane 1,2,3-Tichlorobenzene

1,3-Dichloropropane Acetone

1,2-Dibromoethane Iodomethane

Chlorobenzene Diethylether

1,1,1,2-Tetrachloroethane Carbon disulfide

Styrene Vinyl acetate

Isopropylbenzene 4-Methyl-2-pentanone

Bromobenzene 2-Butanone

1,1,2,2-Tetrachloroethane 2-Hexanone

1,2,3-Trichloropropane trans-1,4-Dichloro-2-butene

n-Propylbenzene
References Cited 123

REFERENCES CITED

Aiken, G.R., and Leenheer, J.A., 1993, Isolation and 

chemical characterization of dissolved and colloidal 

organic matter: Chemistry and Ecology, v. 8, 

p. 135–151.

Aiken, G.R., McKnight, D.M., Thorn, K.A., and Thurman, 

E.M., 1992, Isolation of hydrophilic organic acids from 

water using nonionic macroporous resins: Organic 

Geochemistry, v. 18, p. 567–573.

Anders, R., 1997, Water-quality changes during artificial 

recharge with reclaimed water: M.S. thesis, San Diego 

State University, California, 110 p.

Anders, Robert, and Schroeder, R.A., 1997, Water-quality 

changes during recharge with recycled water at a 

research basin in the Montebello Forebay, Los Angeles 

County, California, in Kendall, D.W., ed., Proceedings 

of the AWRA Symposium Conjunctive Use of Water 

Resources: Aquifer Storage and Recovery, American 

Water Resources Association 33rd National Meeting, 

Long Beach, California, October 19–23, 1997: 

Herndon, Virginia, American Water Resources 

Association, TPS-97-2, p. 285–296.

Arya, L.M., and Paris, J.F., 1981, A physicoempirical model 

to predict the soil moisture characteristics from particle 

size distributions and bulk density data: Soil Science 

Society of America Journal, v. 45, p. 1023–1030.

Audrieth, L. F., and Kleinberg, J., 1953, Non-aqueous 

solvents: New York, John Wiley, p. 148–151. 

AWWA (American Water Works Association), 1992, 

Standard Methods for the Examination of Water and 

Wastewater, 18th Edition, Washington, D.C.

Barber, L.B., II, 1992, Hierarchical analytical approach to 

evaluating the transport and biogeochemical fate of 

organic compounds in sewage-contaminated 

groundwater, Cape Cod, Massachusetts: Chapter 4, in

Lesage, S., and Jackson, R.E., eds., Groundwater 

Contamination and Analysis at Hazardous Waste Sites: 

New York, Marcel Dekker, Inc., p. 73–120. 

Barber, L.B., II, Brown, G.K., Kennedy, K.R., Leenheer, 

J.A., Noyes, T.I., Rostad, C.E., and Thorn, K.A., 1997, 

Water quality at production wells near artificialrecharge basins in Montebello Forebay, Los Angeles 

County, in Kendall, D.W., ed., Proceedings of the 

AWRA Symposium Conjunctive Use of Water 

Resources: Aquifer Storage and Recovery, American 

Water Resources Association 33rd National Meeting, 

Long Beach, California, October 19–23, 1997: 

Herndon, Virginia, American Water Resources 

Association, TPS-97-2, p. 261–272.

Barber, L.B., II, Leenheer, J.A., Noyes, T.I., and Stiles, E.A., 

2001, Nature and transformation of dissolved organic 

matter in treatment wetlands: Environmental Science 

and Technology, v. 35, p. 4805–4816.

Barber, L. B., II, Leenheer, J.A., Noyes, T.I., and Stiles, 

E.A., 1999, Transformation of dissolved organic matter 

in constructed wetlands: Final report for U.S. 

Geological Survey/Bureau of Reclamation Interagency 

Agreement No. 1425-3-AA-81-18180, Bureau of 

Reclamation, Denver, Colorado, 101 p. 

Barber, L.B., II, Leenheer, J.A., Pereira, W.E., Noyes, T.I., 

Brown, G.K., Tabor, C.F., and Writer, J.H., 1995a, 

Organic contamination of the Mississippi River from 

municipal and industrial wastewater, in Meade, R. H., 

ed., Contaminants in the Mississippi River, 1987–1992. 

U.S. Geological Survey Circular 1133, p. 115–135. 

Barber, L.B., II, Leenheer, J.A., Tabor, C.F., Jr., Brown, 

G.K., Noyes, T.I., and Norieaga, M.C., 1995b, Organic 

compounds and sewage-derived contaminants: Chapter 

5, in Moody, J.A., ed., Chemical data for water samples 

collected during four upriver cruises on the Mississippi 

River between New Orleans, Louisiana, and 

Minneapolis, Minnesota, May 1990–April 1992: U.S. 

Geological Survey Open-File Report 94-523, 

p. 221–233.

Barclay's California Code of Regulations, 1978, Ground 

water recharge: Title 26, Sect. 22.60320 (loose leaf).

Berner, R.A., 1971, Principles of chemical sedimentology: 

New York, McGraw-Hill, 240 p.

Britton, L.J., and Greeson, P.E., eds., 1987, Methods for 

collection and analysis of aquatic biological and 

microbiological samples: U.S. Geological Survey 

Techniques of Water-Resources Investigations, Book 5, 

Chapter A4, 363 p.

Burkhardt, M.R., Cinotto, P.J., Frahm, G.W., Woodworth, 

M.T., and Pritt, J.W., 1995, Methods of analysis by the 

U.S. Geological Survey National Water Quality 

Laboratory—Determination of methylene blue active 

substances by spectrophotometry: U.S. Geological 

Survey Open-File Report 95-189, 16 p. 

California Department of Health Services, 1978, Wastewater 

reclamation criteria, an excerpt from the California 

Administrative Code, Title 22, Division 4, 

Environmental Health: Engineering Section, Berkeley 

Calif. (loose leaf).

California Department of Water Resources, Southern 

District, 1961, Planned utilization of the ground water 

basins of the coastal plain of Los Angeles County, 

Appendix A—Ground Water Geology: Bulletin 104, 

150 p.
124 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

California State Water Resources Control Board, 1987, 

Report of the scientific advisory panel on groundwater 

recharge with reclaimed waste water, 29 p.

CFR (Code of Federal Regulations), 1994, Title 40, Part 141, 

Subpart C, Appendix C, Part II, Analysis of 

trihalomethanes in drinking water by liquid/liquid 

extraction (EPA Method 501.2), p. 713–721. 

Condron, L.M., Frossard, E., Newman, R.H., Tekely, P., and 

Morel, J-L, 1997, Use of 31P NMR in the study of soils 

and the environment, in Nanny, M.A., Minear, R.A., 

and Leenheer, J.A., eds., Nuclear Magnetic Resonance 

spectroscopy in environmental chemistry: New York, 

Oxford University Press, p. 247–271.

Coplen, T.B., 1988, Normalization of oxygen and hydrogen 

isotope data: Chemical Geology (Isotope Geoscience 

Section), v. 72, p. 293–297.

Craig, H., 1961a, Isotope variations in meteoric waters: 

Science, v. 133, p. 1702–1703.

_______1961b, Standard for reporting concentrations of 

deuterium and oxygen-18 in natural waters: Science, v. 

133, p. 1833–1834.

Dazzo, F.B., and Rothwell, D.F., 1974, Evaluation of 

porcelain cup water samplers for bacterial samplings: 

Applied Microbiology, v. 27, p. 1172–1174.

Eichelburger, J.W., and Budde, W.L., 1989, Method 524.2, 

Revision 3.0: Cincinnati, Ohio, Environmental 

Monitoring Systems Laboratory, U.S. Environmental 

Protection Agency.

Epstein, S., and Mayeda, T., 1953, Variations of the 18O 

content of waters from natural sources: Geochimica et 

Cosmochimica Acta, v. 4, p. 213–224.

Fetter, C.W., 1988, Journal of Hydrology: Columbus, Ohio, 

Merrill Publishing Company, 592 p.

Field, J.A., Barber, L.B., II, Thurman, E.M., Moore, B.L., 

Lawrence, D.L., and Peake, D.A., 1992a, Fate of 

alkylbenzene sulfonates and dialkyltetralinsulfonates in 

sewage-contaminated groundwater: Environmental 

Science and Technology, v. 26, p. 1140–1148.

Field, J.A., Field, T.M., Polger, T., and Giger, W., 1994, 

Determination of secondary alkane sulfonates in 

sewage wastewaters by solid-phase extraction and 

injection port derivatization gas chromatography/mass 

spectrometry: Environmental Science and Technology, 

v. 28, p. 497–503.

Field, J.A., and Leenheer, J.A., 1988, Response of anionic 

detergents and their carboxylated degradation products 

to the methylene-blue-active substances test: U.S. 

Geological Survey Water-Resources Investigations 

Report 88-4220, p. 614–615. 

Field, J.A., Leenheer, J.A., Thorn, K A., Barber, L.B., II, 

Rostad, C., Macalady, D.L., and Daniel, S.R., 1992b, 

Identification of persistent anionic surfactant-derived 

chemicals in sewage effluent and groundwater: Journal 

of Contaminant Hydrology, v. 9, p. 55–78. 

Field, J.A., Miller, D.J., Field, T.M., Hawthorne, S.B., and 

Giger, W., 1992c, Quantitative determination of 

sulfonated aliphatic and aromatic surfactants in sewage 

sludge by ion-pair/supercritical fluid extraction and 

derivatization gas chromatography/mass spectrometry: 

Analytical Chemistry, v. 64, p. 3161–3167. 

Fischer, R.B., 1961, Quantitative chemical analysis, Second 

Edition: Philadelphia, W. B. Saunders Co., p. 145–148. 

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, 

Chapter A1, 545 p.

Goddard, E.N., Trask, F.D., De Ford, R.K., Rove, O.N., 

Singewald, J.T., Jr., and Overback, R.M., 1948, Rockcolor chart: Geological Society of America, reprinted 

1984.

Guy, H.P., 1969, Laboratory theory and methods for 

sediment analysis: U.S. Geological Survey Techniques 

of Water-Resources Investigations, Book 5, 

Chapter C1, 58 p.

Huffman, E.W.D., Jr., and Stuber, H., 1985, Analytical 

methodology for elemental analysis of humic 

substances, in Aiken, G.R., McKnight, D.M., Wershaw, 

R.L., and MacCarthy, P., eds., Humic substances in soil, 

sediment, and water: New York, John Wiley, 

p. 433–455.

Kendall, C., and Coplen, T.B., 1985, Multisample conversion 

of water to hydrogen by zinc for stable isotope 

determination: Analytical Chemistry, v. 57, 

p. 1437–1440.

Krasner, S.W., McGuire, M.J., Jacangelo, J.G., Patania, N.L., 

Reagan, K.M., and Aieta, E.M., 1989, The occurrence 

of disinfection by-products in U.S. drinking water: 

Journal of American Water Works Association, 

v. 81 no. 8, p. 41–53. 

Land, Michael, Everett, R.R., and Crawford, S.M., 2002, 

Geologic, hydrologic, and water-quality data from 

multiple-well monitoring sites in the Central and West 

Coast Basins, Los Angeles County, California, 1995–

2000: U.S. Geological Survey Open-File Report

01-277, 178 p.

Landsman, S.H., and Fisher, S.M., 1991, Annual report for 

the fiscal year, July 1, 1990, to June 30, 1991: The 

Metropolitan Water District of Southern California. 

LeBlanc, D.R., Garabedian, S.P., Hess, K.M., Gelhar, L.W., 

Quadri, R.D., Stollenwerk, K.G., and Wood, W.W., 

1991, Large-scale natural gradient tracer test in sand 

and gravel, Cape Cod, Massachusetts—1. Experimental 

design and observed tracer movement. Water Resources 

Research, v. 27, p. 895–910. 
References Cited 125

Leenheer, J.A., 1981, Comprehensive approach to 

preparative isolation and fractionation of dissolved 

organic carbon from natural waters and wastewaters: 

Environmental Science and Technology, v. 15, 

p. 578–587. 

Leenheer, J.A., and Huffman, E.W.D., Jr., 1976, 

Classification of organic solutes in water by using 

macroreticular resins: U.S. Geological Survey, Journal 

of Research, v. 4, no. 6, p. 737–751. 

Leenheer, J.A., and Huffman, E.W.D., Jr., 1979, Analytical 

method for dissolved-organic carbon fractionation: U.S. 

Geological Survey Water-Resources Investigations 

79-4, 16 p. 

Leenheer, J.A., Meade, R.H., Taylor, H.E., and Pereira, 

W.E., 1989, Sampling, fractionation, and dewatering of 

suspended sediment from the Mississippi River for 

geochemical and trace-contaminant analysis, in

Mallard, G.E., and Ragone, S.E., eds, U.S. Geological 

Survey Toxic Substances Hydrology Program—

Proceedings of the technical meeting, Phoenix, 

Arizona, September 26–30, 1988: U.S. Geological 

Survey Water-Resources Investigations Report 

88-4220, p. 501–512. 

Leenheer, J.A., and Noyes, T.I., 1984, A filtration and 

column-adsorption system for onsite concentration and 

fractionation of organic substances from large volumes 

of water: U.S. Geological Survey Water-Supply Paper 

2230, 16 p.

Leenheer, J.A., Rostad, C.E., Barber, L.B., Schroeder, R.A., 

Anders, Robert, and Davisson, M.L., 2001, Nature and 

chlorine reactivity of organic constituents from 

reclaimed water in groundwater, Los Angeles County, 

California: Environmental Science and Technology, 

v. 35, p. 3869–3876. 

McCarty, P. L., 1990, Volatile organic chemicals and 

intentional water reuse, Chapter 8 in Ram, N.M., 

Christman, R.F., and Cantor, K.P., eds., Significance 

and treatment of volatile organic compounds in water 

supplies: Boca Raton, Florida, Lewis Publishers,

p. 127–138.. 

McGuire, M.J., and Meadow, R.G., 1988, AWWARF 

[American Water Works Association Research 

Foundation] trihalomethane survey, Journal of 

American Water Works Association, v. 80, no. 1, 

p. 61–68.

Nikkel, M., Mueller, T., Thompson, K., and Rechard, P., 

1989, Assessment of the adequacy of the ground water 

monitoring program for artificial recharge of aquifers in 

the Los Angeles area, California, in Johnson, A.I., and 

Finlayson, D.J., eds., Artificial recharge of ground 

water, Anaheim, California, August 23–27, 1988, 

Proceedings of the International Symposium: American 

Society of Civil Engineers, New York, p. 396–404.

Paulson, G.D., 1976, Sulfate ester conjugates—Their 

synthesis, purification, hydrolysis, and chemical and 

spectral properties, in Kaufman, D.D., Still, G.G., 

Paulson, G.D., and Bandal S.K., eds, Bound and 

conjugated pesticide residues: American Chemical 

Society Symposium Series 29, Chapter 6, Washington, 

D.C., American Chemical Society, p. 86–102. 

Peters, C.A., and Healy, R.W., 1988, The representativeness 

of pore water samples collected from the unsaturated 

zone using pressure-vacuum lysimeters: Ground-Water 

Monitoring Review, v. 8, p. 96–101.

Pitt, W.W., Jr., Jolley, R.L., and Scott, C.D., 1975, 

Determination of trace organics in municipal sewage 

effluents and natural waters by high-resolution ionexchange chromatography: Environmental Science and 

Technology, v. 9, p. 1068–1073. 

Plummer, L.N., Jones, B.F., and Truesdell, A.H., 1984, 

WATEQF-a Fortran IV version of WATEQ, a computer 

program for calculating chemical equilibrium in natural 

waters: U.S. Geological Survey Water-Resources 

Investigations 76-13, 70 p.

Pouchert, C.J., 1985, The Aldrich Library of FT-IR spectra, 

Volumes 1 and 2: Milwaukee, Wisconsin, Aldrich 

Chemical Company, 2,958 p. 

Rathbun, R. E., 1995, Trihalomethane and nonpurgeable 

total organic-halide formation potentials for the 

Mississippi River and some of its tributaries, March–

April 1992: U.S. Geological Survey Open-File Report 

94-336, 55 p. 

Rathbun, R. E., and Bishop, L.M., 1993, Trihalomethane and 

nonpurgeable total organic-halide formation potentials 

for the Mississippi River and some of its tributaries, 

June–August 1991, U.S. Geological Survey Open-File 

Report 93-158, 57 p. 

Rathbun, R. E., and Bishop, L.M., 1994, Trihalomethane and 

nonpurgeable total organic-halide formation potentials 

for the Mississippi River and some of its tributaries, 

September–October 1991, U.S. Geological Survey 

Open-File Report 94-36, 53 p. 

Reichard, E.G., Land, Michael, Crawford, S.M., Johnson, 

Tyler, Everett, R.R., Kulshan, Trayle, Ponti, D.J., 

Halford, K.L., Johnson, T.A., Paybins, K.S., and 

Nishikawa, Tracy, 2003, Geohydrology, geochemistry, 

and ground-water simulation-optimization of the 

Central and West Coast Basins, Los Angeles County, 

California: U.S. Geological Survey Water-Resources 

Investigations Report 03-4065, 56 p, available online at 

the following 

URL:http://pubs.water.usgs.gov/wri34065/

Roberts, P.V., Schreiner, J., and Hopkins, G.D., 1982, Field 

study of organic water quality changes during 

groundwater recharge in the Palo Alto Baylands: Water 

Resources, v. 16, p. 1025–1035. 
126 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Rose, D.L., and Schroeder, M.P., 1995, Methods of analysis 

by the U.S. Geological Survey, National Water Quality 

Laboratory—Determination of volatile organic 

compounds in water by purge and trap capillary gas 

chromatography/mass spectrometry: U.S. Geological 

Survey Open-File Report, 94-708, 26 p.

Rostad, C.E., 1996, Partitioning of lipophilic organic 

contaminants among suspended particulate, colloid, and 

dissolved phases in the Mississippi River: Golden, 

Colorado, Colorado School of Mines, Ph.D. thesis 

4477, 210 p. 

Rostad, C.E., Leenheer, J.A., and Daniel, S.R., 1997, 

Organic carbon and nitrogen content associated with 

colloids and suspended particulates form the 

Mississippi River and some of its tributaries: 

Environmental Science and Technology, v. 31, 

p. 3218–3225.

Rostad, C.E., and Leenheer, J.A., 2000, Identification of 

erioglaucine (Brilliant Blue) as a wastewater marker by 

liquid chromatography/electrospray mass spectrometry, 

in 47th Annual ASMS Conference on Mass 

Spectrometry and Allied Topics, Long Beach, 

California, June 11–15, 2000: American Society for 

Mass Spectrometry, Abstract no. 266.

Rostad, C.E., Pereira, W.E., and Leiker, T.J., 1994, 

Distribution and transport of selected anthropogenic 

organic compounds on Mississippi River suspended 

sediment, May–June 1988: Journal of Contaminant 

Hydrology, v. 16, p. 175–199.

Rostad, C.E., Rees, T.F., and Daniel, S.R., 1998, Colloid 

particle sizes in the Mississippi River and some of its 

tributaries, from Minneapolis to below New Orleans: 

Hydrological Processes, v. 12, p. 25–41. 

Schroeder, R.A., 1995, Potential for chemical transport 

beneath a storm-runoff recharge (retention) basin for an 

industrial catchment in Fresno, California: U.S. 

Geological Survey Water-Resources Investigations 

Report 93-4140, 38 p.

Schroeder, R.A., Anders, Robert, Böhlke, J.K., Michel, R.L., 

and Metge, D.W., 1997, Water quality at production 

wells near artificial-recharge basins in Montebello 

Forebay, Los Angeles County, in Kendall, D.W., ed., 

Proceedings of the AWRA Symposium Conjunctive 

Use of Water Resources: Aquifer Storage and Recovery, 

American Water Resources Association 33rd National 

Meeting, Long Beach, California, October 19–23, 

1997: Herndon, Virginia, American Water Resources 

Association, TPS-97-2, p. 273–284.

Schroeder, R. A., and Anders, Robert, 2002, Transport and 

fate of water-quality indicators after 40 years of 

artificial recharge with treated municipal wastewater to 

the Central Ground-Water Basin in Los Angeles 

County, in Aiken, G. R., and Kuniansky, E. L., eds., 

2002, U.S. Geological Survey Artificial Recharge 

Workshop Proceedings, Sacramento, California, 

April 2–4, 2002: U.S.Geological Survey Open-File 

Report 02-89, p. 42–46, available at the following URL: 

http:water.usgs.gov/ogw/pubs/ofr0289/

Schroeder, R.A., Martin, Peter, and Bohlke, J.K., 1993, 

Chemical, isotopic, and microbiological evidence for 

denitrification during transport of domestic wastewater 

through a thick unsaturated zone in the Mojave Desert, 

San Bernardino County, California: U.S. Geological 

Survey Open-File Report 93-414, 11 p.

Shinozuka, N., and Nihei, Y., 1994, Size of aqueous 

solutions studied by light scattering, in Senesi, N., and 

Miano, T.M., eds., Humic substances in the global 

environment and implications on human health: New 

York, Elsevier Science, p. 889–894.

Singer, P.C., and Chang, S.D., 1989, Correlations between 

trihalomethanes and total organic halides formed during 

water treatment: Journal of American Work Works 

Association v. 81, p. 61–65. 

Sloss, E.M., Geschwind, S.A., McCaffrey, D.F., and Ritz, 

B.R., 1996, Groundwater recharge with reclaimed 

water—an epidemiologic assessment in Los Angeles 

County, 1987–1991: Rand report prepared for the Water 

Replenishment District of Southern California, Rand 

Report ISBN: 0-8330-2385-3, Santa Monica, 

California, 124 p.

Steelink, C., 1985, Implications of elemental characteristics 

of humic substances, in Aiken, G.R., McKnight, D.M., 

Wershaw, R.L., and MacCarthy, P., eds., Humic 

substances in soil, sediment, and water: New York, John 

Wiley, p. 457–476. 

Stevenson, F.J., 1982, Spectroscopic approaches, Chapter 11, 

in Humus chemistry: genesis, composition, reactions: 

New York, John Wiley, p. 264–284.

Stiff, H.A., Jr., 1951, The interpretation of chemical water 

analysis by means of patterns: Journal of Petroleum 

Technology, v. 3, p. 15–17.

Swisher, R.D., 1987, Surfactant biodegradation (second 

edition): New York, Marcel Dekker, 1,085 p. 

Tabor, C.F., and Barber, L.B., II, 1996, Fate of linear 

alkylbenzene sulfonate in the Mississippi River: 

Environmental Science and Technology, v. 30, 

p. 161–171. 

Thorn, K.A., and Aiken, G.R., 1998, Biodegration of crude 

oil into nonvolatile organic acids in a contaminated 

aquifer near Bemidji, Minnesota: Organic 

Geochemistry, v. 29, p. 909–931.
References Cited 127

Thurman, E.M., Willoughby, T., Barber, L.B., II, and Thorn, 

K.A., 1987, Determination of alkylbenzene sulfonate 

surfactants in groundwater using macroreticular resins 

and carbon-13 nuclear magnetic resonance 

spectrometry: Analytical Chemistry, v. 59, 

p. 1798–1802.

Timme, P.J., 1994, National Water Quality Laboratory 1994 

services catalog: U.S. Geological Survey Open-file 

Report 94-304, 103 p.

Tombacz, E., and Regdon, I., 1994, Humic substances as 

various colloidal systems, in Senesi, N., and Miano, 

T.M., eds., Humic substances in the global environment 

and implications on human health: New York, Elsevier 

Science, p. 139–144.

Trehy, M.L., Gledhill, W.E., and Orth, R.G., 1990, 

Determination of linear alkylbenzenesulfonates and 

dialkyltetralinsulfonates in water and sediment by gas 

chromatography/mass spectrometry: Analytical 

Chemistry, v. 62, p. 2581–2586. 

Troxler Electronic Laboratories, Inc., 1983, Instruction 

manual, depth moisture gages, Research Triangle Park, 

North Carolina, 55 p.

_______1992, Sentry 200-AP user's manual, Research 

Triangle Park, North Carolina, 5 chapters and 

appendixes A–F.

Umari, A.M.J., Martin, P., Schroeder, R.A., Duell, L.F.W., Jr., 

and Fay, R.G., 1995, Potential for ground-water 

contamination from movement of wastewater through 

the unsaturated zone, upper Mojave River Basin, 

California: U.S. Geological Survey Water-Resources 

Investigations Report 93-4137, 83 p.

U.S. Environmental Protection Agency, Office of Water, 

1996, Drinking water regulations and health advisories, 

EPA 822-B-96-002, 11 p.

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

1983, Methods for the determination of organic 

substances in water and fluvial sediments: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, Book 5, Laboratory Analysis, 

Chapter A3, 173 p. 

Wilson, L.G., Amy, G.L., Gerba, C.P., Gordon, H., Johnson, 

B., and Miller, J., 1995, Water quality changes during 

soil aquifer treatment of tertiary effluent: Water 

Environmental Research, v. 67, p. 371–376. 
128 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

THIS PAGE INTENTIONALLY LEFT BLANK
Appendixes 129

APPENDIXES
130 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 1. Periodic water-level measurements made near the research basin, Montebello Forebay, Los Angeles County, California, between January 

1993 and December 1995—Continued

State

well No.

(Local identifier)

Date Water

 level

State

well No. Date Waterlevel

State 

well No. Date Waterlevel

2S/11W-18L27 04-16-93 162.51 09-27-94 144.13 06-01-94 158.74

(PR8) 08-10-93 161.51 10-11-94 157.18 07-06-94 158.63

08-11-93 160.78 04-11-95 162.80 08-18-94 148.03

08-12-93 160.46 05-04-95 163.74 08-30-94 148.64

08-13-93 160.27 06-27-95 161.67 09-06-94 146.37

08-16-93 160.03 07-18-95 161.66 09-07-94 151.18

08-23-93 158.82 07-28-95 161.97 09-09-94 151.73

08-24-93 158.47 07-30-95 163.24 09-12-94 150.97

08-28-93 159.15 07-31-95 162.74 09-14-94 150.60

08-29-93 159.06 08-08-95 161.59 09-16-94 150.17

08-30-93 159.07 09-08-95 158.63 09-19-94 149.74

11-17-93 157.50 09-11-95 157.38 09-20-94 149.56

03-10-94 156.36 09-19-95 159.16 09-21-94 149.36

03-24-94 157.71 09-29-95 155.81 09-22-94 149.16

04-04-94 159.48 10-04-95 152.40 09-23-94 149.01

04-05-94 159.46 2S/11W-18L28 04-16-93 162.61 09-27-94 144.43

04-06-94 160.19 (PR9) 08-10-93 161.59 10-11-94 157.02

04-07-94 160.29 08-11-93 160.98 11-16-94 160.14

04-08-94 160.26 08-12-93 160.80 04-11-95 162.95

04-21-94 159.86 08-13-93 160.47 05-04-95 163.74

06-01-94 158.65 08-16-93 160.19 06-27-95 161.71

07-06-94 158.52 08-23-93 158.95 07-18-95 161.78

08-18-94 147.93 08-24-93 158.90 07-28-95 162.07

08-30-94 148.46 08-28-93 159.21 07-30-95 164.42

09-06-94 146.24 08-29-93 159.21 07-31-95 164.48

09-07-94 147.81 08-30-93 160.16 08-08-95 161.66

09-09-94 148.54 11-17-93 157.73 09-06-95 158.74

09-12-94 148.28 03-10-94 156.39 09-11-95 157.44

09-14-94 148.06 03-24-94 157.66 09-19-95 160.43

09-16-94 147.81 04-04-94 159.52 09-29-95 156.43

09-19-94 147.71 04-05-94 159.90 10-04-95 152.56

09-20-94 147.62 04-06-94 161.16 2S/11W-18L29 04-16-93 162.06

09-21-94 147.18 04-07-94 161.31 (PR10) 08-10-93 161.32

09-22-94 147.04 04-08-94 161.29 08-11-93 160.42

09-23-94 146.90 04-21-94 160.09 08-12-93 160.15

Appendix 1. Periodic water-level measurements made near the research basin, Montebello Forebay, Los Angeles County, California, between January 

1993 and December 1995

[Water level: altitude, in feet above sea level; local identifier for wells near research basin in parentheses; —, no data]
Appendixes 131

Appendix 1. Periodic water-level measurements made near the research basin, Montebello Forebay, Los Angeles County, California, between January 

1993 and December 1995—Continued

State

well No. Date Water level State well No. Date Water level State well No. Date Water level

08-13-93 159.97 07-30-95 162.75 09-21-94 147.99

08-16-93 159.32 07-31-95 162.40 09-22-94 147.82

08-23-93 158.35 08-08-95 161.41 09-23-94 147.65

08-24-93 158.26 09-06-95 158.24 09-27-94 144.18

08-28-93 158.62 09-11-95 156.99 10-11-94 156.72

08-29-93 158.55 09-19-95 158.36 11-16-94 160.02

08-30-93 158.54 09-29-95 155.10 04-11-95 162.75

11-17-93 156.79 10-04-95 152.03 05-04-95 163.60

03-10-94 155.93 2S/11W-18L30 04-16-93 162.35 06-27-95 161.43

04-04-94 159.34 (PR11) 08-10-93 160.84 07-18-95 161.98

04-05-94 159.34 08-11-93 160.71 07-28-95 162.04

04-06-94 159.76 08-12-93 160.28 07-30-95 163.79

04-07-94 159.81 08-16-93 159.60 07-31-95 162.97

04-08-94 159.73 08-23-93 158.63 08-08-95 161.60

04-21-94 159.71 08-24-93 158.55 09-06-95 158.52

06-01-94 157.93 08-28-93 159.25 09-11-95 157.21

07-06-94 158.18 08-29-93 158.91 09-19-95 159.62

08-18-94 147.72 08-30-93 158.88 09-29-95 156.18

08-30-94 148.22 11-17-93 157.16 10-04-95 152.33

09-06-94 145.97 03-10-94 156.16 2S/11W-18L31 11-16-94 160.17

09-07-94 147.04 04-04-94 159.49 (WP1) 04-11-95 162.98

09-09-94 147.66 04-05-94 159.78 05-04-95 163.72

09-12-94 147.42 04-06-94 160.53 06-27-95 161.71

09-14-94 147.20 04-07-94 160.63 07-18-95 161.73

09-16-94 146.94 04-08-94 160.57 07-28-95 162.07

09-19-94 146.57 04-21-94 159.98 07-30-95 164.84

09-20-94 146.48 06-01-94 158.15 07-31-95 163.40

09-21-94 146.35 07-06-94 157.43 08-08-95 161.64

09-22-94 146.21 08-18-94 147.84 09-19-95 160.85

09-23-94 146.06 08-30-94 148.45 10-04-95 —

09-27-94 143.84 09-06-94 146.13 2S/11W-18L32 11-16-94 159.74

10-11-94 156.22 09-07-94 148.85 (WP2) 04-11-95 162.57

11-16-94 159.59 09-09-94 149.90 05-04-95 163.31

04-11-95 162.42 09-12-94 149.45 06-27-95 161.30

05-04-95 163.39 09-14-94 149.12 07-18-95 161.35

06-27-95 161.05 09-16-94 148.75 07-28-95 161.67

07-18-95 161.37 09-19-94 148.30 07-30-95 164.31

07-28-95 161.79 09-20-94 148.18 07-31-95 162.97
132 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 1. Periodic water-level measurements made near the research basin, Montebello Forebay, Los Angeles County, California, between January 

1993 and December 1995—Continued

State

well No. Date Water

 level

State

well No. Date Water

level

State 

well No. Date Water

level

08-08-95 161.25 09-19-95 138.05 11-23-92 127.02

09-19-95 160.33 09-29-95 134.25 12-09-92 127.31

09-29-95 156.73 2S/11W-19E1 04-21-94 145.08 01-20-93 137.13

10-04-95 152.18 06-02-94 137.98 02-19-93 142.51

2S/11W-18L33 07-18-95 162.31 07-06-94 139.42 04-12-93 142.01

(WP3) 09-19-95 157.64 04-11-95 150.46 11-17-93 137.04

09-29-95 — 05-04-95 148.55 03-10-94 131.48

10-04-95 — 06-27-95 145.53 04-04-94 139.17

2S/11W-18L34 07-18-95 161.67 07-31-95 148.52 04-05-94 138.92

(WP4) 09-19-95 157.62 09-11-95 136.40 04-07-94 137.73

09-29-95 155.91 09-19-95 132.99 04-21-94 137.31

10-04-95 153.08 2S/11W-19C1 07-20-92 141.06 06-01-94 137.47

2S/11W-18L35 07-18-95 162.11 08-14-92 136.66 07-06-94 138.19

(WP5) 09-19-95 157.61 09-30-92 129.04 04-11-95 144.22

09-29-95 154.46 11-23-92 137.66 05-04-95 141.21

10-04-95 151.48 12-09-92 143.42 06-27-95 141.52

2S/11W-18P1 07-20-92 141.80 01-20-93 148.35 07-31-95 143.57

08-14-92 137.85 02-19-93 150.67 09-19-95 131.43

09-30-92 132.08 04-12-93 146.71 09-29-95 126.98

11-23-92 136.81 11-17-93 139.95 2S/12W-25Q1 07-20-92 95.50

12-09-92 147.31 03-10-94 136.96 08-14-92 92.15

01-20-93 150.15 04-04-94 149.86 09-30-92 87.70

02-19-93 153.67 04-05-94 148.96 11-23-92 100.14

04-12-93 148.75 04-07-94 147.81 12-09-92 99.91

11-17-93 139.10 04-21-94 149.39 02-19-93 113.36

03-10-94 139.71 06-02-94 145.68 04-12-93 115.07

04-04-94 151.88 07-06-94 144.20 11-17-93 102.70

04-05-94 151.19 04-11-95 148.05 03-10-94 113.64

04-07-94 149.54 05-04-95 151.81 04-04-94 109.50

04-21-94 152.74 06-27-95 144.23 04-05-94 109.82

06-02-94 142.33 07-31-95 151.55 04-07-94 109.16

07-06-94 143.49 09-11-95 141.61 04-21-94 109.66

04-11-95 149.17 09-19-95 139.85 06-02-94 105.76

05-04-95 155.60 09-29-95 134.35 07-06-94 111.68

06-27-95 143.04 2S/12W-24R1 07-20-92 130.76 04-11-95 117.00

07-31-95 155.33 08-14-92 125.54 05-04-95 113.01

09-11-95 139.48 09-30-92 115.38 06-27-95 113.10

07-31-95 109.44
Appendixes 133

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)

2S/11W-18L10LYS 08/10/93 2110 — — — — 190 54 14 4.4 76 —(CR-RED at 50 ft) 08/11/93 1900 — — — — 200 56 14 4.4 77 —

08/12/93 1655 — — — — 210 58 15 1.8 80 —08/13/93 1020 — — — — 210 58 15 4.6 79 —08/16/93 1050 — — — — 210 58 15 4.8 81 —08/23/93 1054 — — — — 200 57 15 4.5 81 —08/24/93 1800 — — — — 180 50 14 4.7 77 —08/28/93 1900 — — — — 200 57 14 5 78 —08/29/93 1800 — — — — 220 62 15 4.5 74 —08/30/93 1118 — — — — 200 56 15 4.7 73 —

2S/11W-18L11LYS 08/10/93 2135 — — — — 170 47 13 3.4 90 —(CR-ORG at 25 ft) 08/11/93 1905 — — — — 180 49 13 3.6 91 —

08/12/93 1700 — — — — 180 52 13 .6 90 —08/13/93 1025 — — — — 180 51 13 3.7 91 —08/16/93 1055 — — — — 190 53 13 4 91 —08/23/93 1109 — — — — 190 53 13 3.8 92 —08/24/93 1800 — — — — 180 49 13 3.9 89 —08/28/93 1900 — — — — 190 54 14 4.3 90 —08/29/93 1800 — — — — 200 55 14 3.7 88 —08/30/93 1115 — — — — 190 54 13 4 85 —

2S/11W-18L13LYS 08/10/93 2140 — — — — 250 73 17 9.2 120 —(CR-BLU at 13.5 ft) 08/11/93 1910 — — — — 240 69 16 9.4 120 —

08/12/93 1710 — — — — 240 70 16 .8 120 —08/13/93 1030 — — — — 250 71 17 9 120 —08/16/93 1100 — — — — 250 72 16 9.8 130 —08/23/93 1112 — — — — 240 70 16 9.7 120 —

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen—alkalinity[See table 1 for explanation of local identifier listed under station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; μS/cm, microsiemens per centimeter; oC, degrees Celsius; ft, feet below basin floor or land surface; 

mg/L, milligrams per liter; —, no data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; TF, Teflon lysimeter; MLS, multilevel sampler]
134 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/24/93 1800

—

—

—

— 230 65 16 10 120

—

08/28/93 1900

—

—

—

— 240 69 16 11 130

—

08/29/93 1800

—

—

—

— 250 72 16 9.4 130

—

08/30/93 1120

—

—

—

— 210 59 16 9.6 120

—

2S/11W-18L14A 08/10/93 2110 1.4 7.3 800 20.1 200 58 13 4.6 87

—

(MLS20) 08/11/93 2000

— 7.3 756 20.3 180 52 12 4.5 85 150

08/12/93 2000

— 7.2 774 19.5 200 57 13 3.3 87 160

08/13/93 1920

— 7.1 809 19.7 190 55 13 4.5 87 160

08/16/93 1855 .4 7.3 860 19.5 220 62 15 5.2 89 16008/23/93 1900 .2 7.1 843 19.5 220 61 16 5.3 92 16008/24/93 1700

— 7.1 832

— 220 62 15 4.8 89 170

08/28/93 1730

— 7.1 802 21.4 200 56 14 4.4 84 160

08/29/93 1635

— 7 791 21.7 190 55 13 4.7 81 160

08/30/93 1730 .4 7.2 778 20 200 56 14 4.6 85 150

2S/11W-18L14B 08/10/93 2040 1.4 7.2 901 20.8 240 66 17 7 92 180(MLS19) 08/11/93 1930

— 7.2 769 20.6 180 54 12 5.2 88 160

08/12/93 1920

— 7.2 926 19.7 260 73 19 7.2 97 190

08/13/93 1845

— 7.1 938 20.9 240 67 17 7.2 94 190

08/16/93 1818 .4 7.3 916 20.5 230 64 16 7.6 94 17008/23/93 1830 .4 7.2 918 20 240 66 17 7.2 93 17008/24/93 1650

— 7.1 914

— 250 70 18 7.2 97 170

08/28/93 1715

— 7.2 895 22.6 230 63 17 6.7 88 180

08/29/93 1620

— 7.2 890 21.7 240 66 17 6.7 94 170

08/30/93 1715 .6 7.3 885 20 240 66 17 7.1 90 170

2S/11W-18L14C 08/10/93 2005 1.2 7.2 952 21.5 260 74 19 7.9 94 190(MLS18) 08/11/93 1900

— 7.2 951 21.1 250 72 18 8.1 94 190

08/12/93 1845

— 7.2 931 20.9 250 70 18 8.4 94 200

08/13/93 1800

— 7.1 929 21.6 230 64 17 7.6 94 190

08/16/93 1745 0.4 7.2 931 21 230 65 16 8 95 170

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 135

08/23/93 1815 .4 7.2 917 20.5 240 66 18 7.9 94 17008/24/93 1615 — 7.1 916 22.9 250 72 18 7.6 94 16008/28/93 1655 — 7.1 903 23.5 230 64 17 6.9 87 18008/29/93 1600 — 7.1 894 22.2 240 67 18 7.4 87 17008/30/93 1630 .4 7.3 895 20.5 250 70 17 7.3 85 170

2S/11W-18L14D 08/10/93 1930 — 7.4 964 21.6 270 76 19 8.8 100 190(MLS17) 08/11/93 1830 — 7.3 952 21.2 — — — — — 200

08/12/93 1800 — 7.3 946 21.6 240 68 17 7.9 90 21008/13/93 1745 — 7.2 952 22 240 69 17 8.2 100 20008/16/93 1705 .4 7.3 973 21 240 67 17 9.2 100 18008/23/93 1800 .4 7.3 984 21 260 73 19 10 99 18008/24/93 1550 — 7.2 981 23.2 260 73 19 8.6 99 17008/28/93 1640 — 7.1 952 23.3 240 67 18 7.7 93 19008/29/93 1540 — 7.1 951 23.3 250 71 18 8.5 93 19008/30/93 1600 .4 7.3 952 21 250 72 18 8.4 95 180

2S/11W-18L14E 08/10/93 1915 1.4 7.3 877 21.2 250 69 18 7.1 91 170(MLS16) 08/11/93 1745 — 7.3 874 22.1 230 67 16 8.1 88 170

08/12/93 1700 — 7.2 871 21.8 240 68 17 6.8 89 18008/13/93 1720 — 7.2 878 21.1 220 63 16 6.9 89 18008/16/93 1620 .6 7.2 927 21 230 64 17 8 97 17008/23/93 1710 .4 7.1 952 21 260 73 19 7.9 93 16008/24/93 1525 — 7.1 955 23.1 280 79 20 7.2 88 16008/28/93 1620 — 7.1 900 23.1 240 67 18 6.8 81 17008/29/93 1510 — 7 904 23.3 250 69 18 7.2 80 17008/30/93 1540 .4 7.2 904 21 250 72 18 7.5 82 160

2S/11W-18L14F 08/10/93 1755 1.4 7.2 839 21.7 230 64 17 7.2 84 160(MLS15) 08/11/93 1700 — 7.1 851 22.3 — — — — — 160

08/12/93 1620 — 7.1 858 21.7 250 70 18 6.5 78 150

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
136 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/13/93 1700

— 7 836 21.1 240 66 17 7.1 77 150

08/16/93 1530 0.4 7.1 914 21.5 270 75 20 8.4 80 15008/23/93 1700 .6 7 940 21.5 290 81 20 8.1 75 15008/24/93 1450

— 7 940

— 290 82 21 8 78 150

08/28/93 1600

— 6.9 892 23.2 270 74 20 7.2 70 150

08/29/93 1450

— 6.9 912 22.9 280 79 20 8.3 74 150

08/30/93 1440 .4 7.1 878 21 270 78 19 7.6 69 140

2S/11W-18L14G 08/10/93 1710 1.2 7.3 855 22.3 250 70 18 7.8 74 150(MLS14) 08/11/93 1610

— 7 856 23.1 250 72 18 7.1 77 160

08/12/93 1500

— 7.1 880 22.5 260 71 19 8.1 72 150

08/13/93 1645

— 7.1 912 21.3 270 75 20 8.1 74 170

08/16/93 1550 .4 7.1 972 22 290 82 21 9 78 16008/23/93 1630 .6 7.1 950 22 290 82 21 9.8 80 15008/24/93 1430

— 6.9 935

— 290 83 21 7.7 78 150

08/28/93 1500

— 7 923 22.8 270 75 20 8 75 150

08/29/93 1250

— 7 934 21.9 280 78 20 8.2 79 150

08/30/93 1430 .4 7 949 21 290 81 20 7.9 80 160

2S/11W-18L14H 08/10/93 1625 1.2 7.1 895 22.6 270 78 19 7.8 72 150(MLS13) 08/11/93 1545

— 7 909 22.5 290 81 20 9.1 74 160

08/12/93 1445

— 7 932 23.6 290 83 21 7.1 73 160

08/13/93 1620

— 7 955 21.8 290 81 20 7.6 77 170

08/16/93 1430 .6 7.1 1,010 23.5 270 78 19 8.5 97 16008/23/93 1600 .4 7.1 972 22.5 280 80 20 8.8 85 16008/24/93 1315

— 7.1 970 24.5 300 86 21 7.6 90 160

08/28/93 1515

— 6.9 957 23.4 270 78 19 8.1 80 160

08/29/93 1235

— 7 952 22 300 85 20 7.5 82 160

08/30/93 1310 .4 7.1 950 21.5 290 81 20 7.3 79 160

2S/11W-18L14I 08/10/93 1525 1.6 7.1 898 23.4 290 85 19 6.9 72 140(MLS12) 08/11/93 1520

— 7 917 22.5

—

—

—

—

— 150

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 137

08/12/93 1315 — 7 932 22.7 300 86 20 7.2 73 16008/13/93 1530 — 7 965 22 300 85 21 7.3 81 18008/16/93 1250 0.4 7.1 1,020 24 250 73 17 7.8 110 16008/23/93 1520 .6 7.1 990 23 290 82 21 8.6 87 17008/24/93 1220 — 7.1 983 24.5 290 83 20 7.4 88 16008/28/93 1335 — 7 965 23.4 280 80 20 8.2 79 16008/29/93 1220 — 7.1 957 22.3 290 83 20 7.1 78 16008/30/93 1230 .4 7.1 950 22 300 85 20 7.3 78 150

2S/11W-18L14J 08/10/93 1500 1.4 7 922 22.7 290 84 20 7.1 76 150(MLS11) 08/11/93 1240 — 6.9 914 22.8 300 87 20 6.8 77 150

08/12/93 1250 — 7 956 22.6 300 87 21 7.2 77 18008/13/93 1500 — 7.1 993 22.5 270 79 18 6.9 93 19008/16/93 1245 .6 7.3 1,040 24.5 240 68 16 7.9 120 17008/23/93 1500 .4 7.1 1,000 23 290 82 20 9 89 17008/24/93 1200 — 7.1 993 24 300 85 20 7.8 92 17008/28/93 1315 — 6.9 974 24 290 82 20 8 79 17008/29/93 1200 — 7 970 23 300 87 21 7 79 16008/30/93 1215 .4 7.1 965 22.5 310 88 21 7.3 84 160

2S/11W-18L14K 08/10/93 1415 1.4 7.1 952 23.8 300 82 22 10 83 170(MLS10) 08/11/93 1210 — 7 931 22.4 300 89 19 8.9 79 160

08/12/93 1220 — 7.1 989 22.5 310 88 21 8.2 85 22008/13/93 1300 — 7.2 1,010 21.8 260 74 17 8 110 19008/16/93 1200 .6 7.4 1,050 25.5 230 67 16 9.2 120 17008/23/93 1230 .4 7.3 1,040 24 270 77 19 9.6 110 19008/24/93 1105 — 7.1 1,030 — 280 79 20 9.8 110 —08/28/93 1250 — 7 1,010 23.8 300 85 21 9.2 84 18008/29/93 1125 — 7.1 1,000 23.1 310 90 21 8.2 84 18008/30/93 1150 .4 7.1 990 23 310 89 21 7.8 84 170

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
138 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14L 08/10/93 1345 1.4 7 938 23 290 82 20 7.8 78 160 (MLS9) 08/11/93 1115

— 7.1 951 22.7 300 85 21 9.6 81 160

08/12/93 1130

— 7.2 1,020 22.9 300 84 22 10 83 220

08/13/93 1230

— 7.2 1,030 22.4 240 66 18 10 110 190

08/16/93 1130 .6 7.4 1,060 25.5 230 64 17 11 120 18008/23/93 1210 .4 7.4 1,070 24 260 69 20 12 120 20008/24/93 1045

— 7.4 1,060

— 250 70 19

— 120 200

08/28/93 1230

— 7.2 1,090 23.9 300 81 23 13 100 220

08/29/93 1105

— 7.2 1,070 23.1 310 87 23 11 98 220

08/30/93 1130 .4 7.2 1,050 23 300 81 23 11 95 200

2S/11W-18L14M 08/10/93 1230 1.4 7.3 1,000 23.6 240 69 17 10 100 210(MLS8) 08/11/93 1030

— 7.3 1,010 22.6 250 72 17 9.8 100 210

08/12/93 1100

— 7.3 1,000 23.5 270 76 19 9.5 110 230

08/13/93 1150

— 7.4 1,000 22.3 240 66 17 9.1 110 220

08/16/93 1100 .4 7.4 1,030 25.5 240 68 16 10 110 19008/23/93 1145 .6 7.4 1,030 24.5 240 68 18 7.9 120 19008/24/93 1020

— 7.3 1,030 24.1 250 69 18 9.8 110 180

08/28/93 1120

— 7.2 1,010 24.4 240 67 17 11 110 230

08/29/93 1050

— 7.3 1,010 23 250 72 18 8.8 110 200

08/30/93 1050 .4 7.3 995 23.5 260 74 18 8.9 100 200

2S/11W-18L14N 08/10/93 1115 .4 7.5 1,090 24.6 230 64 18 12 130 250(MLS7) 08/11/93 1000

— 7.5 1,080 23.5 240 65 18 12 130 250

08/12/93 1030

— 7.5 1,050 24 230 62 18 12 130 250

08/13/93 1040

— 7.5 1,050 22.6 220 60 17 11 120 230

08/16/93 1015 .4 7.5 1,070 26 220 60 17 13 130 19008/23/93 1100 .4 7.5 1,060 24.5 230 64 18 10 120 200

08/24 /93 0930

— 7.5 1,060

— 230 62 18 2.5 120 190

08/28/93 1050

— 7.5 1,040 24.6 220 59 17 12 120 220

08/29/93 1030

— 7.5 1,030 24.2 230 64 18 11 120 240

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 139

08/30/93 1030 0.4 7.6 1,040 24.5 240 65 18 10 120 230

2S/11W-18L14O 08/10/93 1010 .2 7.5 1,080 19.5 240 65 18 .1 130 250(MLS6) 08/11/93 0930 — 7.4 1,050 23.1 220 61 16 2.2 120 230

08/12/93 0930 — 7.4 1,040 24 230 63 17 13 110 26008/13/93 1015 — 7.5 1,060 22.3 230 64 17 10 120 24008/16/93 1000 .6 7.5 1,060 26 230 63 17 11 120 20008/23/93 1050 .4 7.6 1,050 25 240 66 18 10 120 20008/24/93 0850 — 7.4 1,050 24.1 230 64 18 — 120 20008/28/93 1020 — 7.5 1,030 23.9 240 65 18 12 120 21008/29/93 1015 — 7.5 1,030 24.3 240 65 18 11 120 22008/30/93 1000 .4 7.4 1,020 24.5 240 67 18 9.8 110 220

2S/11W-18L14P 08/10/93 0846 .4 7.6 1,060 24.2 230 67 16 11 120 250(MLS5) 08/11/93 0900 — 7.4 1,040 23.6 230 66 16 9.2 120 250

08/12/93 0900 — 7.3 1,030 23.6 240 66 17 9.9 110 26008/13/93 0845 — 7.4 1,050 22.1 220 61 16 10 120 28008/16/93 0900 .6 7.6 1,060 25.5 240 66 17 13 120 23008/23/93 0945 .4 7.7 1,050 25 230 63 18 14 130 22008/24/93 0830 — 7.4 1,050 24.1 230 63 17 — 120 21008/28/93 0930 — 7.5 1,040 24.7 220 62 16 12 120 22008/29/93 0930 — 7.6 1,030 24.6 230 63 17 11 120 24008/30/93 0920 .4 7.5 1,020 25 230 65 17 10 120 240

2S/11W-18L14Q 08/10/93 0845 .4 7.4 1,050 23.3 220 62 16 1.1 130 270(MLS4) 08/11/93 0845 — 7.4 1,060 23.9 200 57 15 9.4 130 290

08/12/93 0845 — 7.5 1,050 24.6 220 61 16 11 130 27008/13/93 0810 — 7.4 1,070 22.8 210 59 15 9.7 130 24008/16/93 0845 .4 7.6 1,080 25.5 220 62 15 11 130 22008/23/93 0920 .6 7.8 1,070 25 220 64 15 10 130 22008/24/93 0815 — 7.3 1,060 24.3 230 66 15 9.7 130 210

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
140 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/28/93 0930

— 7.4 1,050 24.8 220 63 15 11 120 230

08/29/93 0910

— 7.6 1,040 24.6 220 63 15 10 130 250

08/30/93 0820 0.4 7.5 1,030 25 220 64 15 10 130 250

2S/11W-18L15LYS 08/10/93 1955

—

—

—

— 140 33 13 4.4 70

—

(SS-RED at 49 ft) 08/11/93 1815

—

—

—

— 140 35 13 4.2 73

—

08/12/93 1550

—

—

—

— 140 37 12 .7 71

—

08/13/93 0905

—

—

—

— 140 36 12 3.9 71

—

08/16/93 0750

—

—

—

— 150 39 12 4.3 71

—

08/23/93 0850

—

—

—

— 150 40 13 4.3 80

—

08/24/93 1800

—

—

—

—

—

—

—

—

—

—

08/28/93 1900

—

—

—

— 140 37 12 4.8 77

—

08/29/93 1800

—

—

—

— 160 40 14 4.4 83

—

08/30/93 0900

—

—

—

— 160 42 13 4.4 79

—

2S/11W-18L16LYS 08/10/93 2015

—

—

—

— 51 15 3.1 3.6 93

—

(SS-ORG at 25 ft) 08/11/93 1835

—

—

—

— 82 25 4.7 3.5 110

—

08/12/93 1555

—

—

—

— 140 42 8 .1 96

—

08/13/93 0915

—

—

—

— 150 46 9.3 4 92

—

08/16/93 0755

—

—

—

— 170 51 9.7 4.4 93

—

08/23/93 0851

—

—

—

— 100 28 7.8 4.7 96

—

08/24/93 1800

—

—

—

— 75 20 5.9 3.9 92

—

08/28/93 1900

—

—

—

— 120 32 9.4 4.9 89

—

08/29/93 1800

—

—

—

— 110 30 9.1 3.9 88

—

08/30/93 0900

—

—

—

— 270 75 19 4.2 85

—

2S/11W-18L17LYS 08/10/93 2025

—

—

—

— 170 51 9.3 6.5 110

—

(SS-YEL at 15 ft) 08/11/93 1830

—

—

—

— 170 52 9.5 6.5 110

—

08/12/93 1610

—

—

—

— 190 57 12 5 89

—

08/13/93 0920

—

—

—

— 200 58 13 6.7 88

—

08/16/93 0800

—

—

—

— 230 68 15 6.9 90

—

08/23/93 0853

—

—

—

— 210 60 15 6.9 92

—

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 141

08/24/93 1800 — — — — 190 52 14 6.9 92 —08/28/93 1900 — — — — 240 65 18 8.6 86 —08/29/93 1800 — — — — 220 61 17 7 86 —08/30/93 0900 — — — — 250 70 19 7.2 80 —

2S/11W-18L18LYS 08/10/93 2100 — — — — 180 49 15 8.4 110 —(SS-GRE at 10 ft) 08/11/93 1840 — — — — 240 72 15 9.4 110 —

08/12/93 1615 — — — — 230 67 16 2.6 100 —08/13/93 0925 — — — — 250 71 18 8.9 94 —08/16/93 0805 — — — — 260 74 19 9.6 100 —08/23/93 0854 — — — — 230 64 17 9.5 120 —08/24/93 1800 — — — — — — — — — —08/28/93 1900 — — — — 220 63 16 10 120 —08/29/93 1800 — — — — 230 65 16 8.7 120 —08/30/93 0900 — — — — 250 70 19 8.8 110 —

2S/11W-18L19LYS 08/10/93 2110 — — — — — — — 3.5 — —(SS-BLU at 5 ft) 08/11/93 1845 — — — — 140 40 8.7 6.1 180 —

08/12/93 1620 — — — — 150 45 8.7 2.9 180 —08/13/93 0930 — — — — 130 43 6.1 5.2 180 —08/16/93 0810 — — — — 150 47 7.3 5.7 170 —08/23/93 0855 — — — — 100 33 5.3 5.5 180 —08/24/93 1800 — — — — 72 24 2.8 4.9 190 —08/28/93 1900 — — — — 110 37 5.3 6.5 180 —08/29/93 1800 — — — — — — — .2 — —08/30/93 0900 — — — — 120 38 6.1 5.8 170 —

2S/11W-18L20LYS 08/10/93 2107 — — — — 280 77 21 9.4 76 —(CR-YEL at 15 ft) 08/11/93 1855 — — — — 270 75 20 9.2 70 —

08/12/93 1645 — — — — 300 83 22 0.1 76 —08/13/93 0940 — — — — 280 77 21 9.2 73 —

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
142 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 0925

—

—

—

— 320 90 23 10 83

—

08/23/93 0902

—

—

—

— 290 80 21 9.8 89

—

08/24/93 1800

—

—

—

— 280 76 21 9.2 88

—

08/28/93 1900

—

—

—

— 300 84 21 9.1 87

—

08/29/93 1800

—

—

—

— 320 92 22 7.6 87

—

08/30/93 1022

—

—

—

— 300 83 22 8 84

—

2S/11W-18L21LYS 08/10/93 2145

—

—

—

—

—

—

—

—

—

—

(CR-GRE at 9 ft) 08/11/93 1850

—

—

—

— 150 40 11 4.5 190

—

08/12/93 1635

—

—

—

— 190 51 14 4 160

—

08/13/93 0935

—

—

—

— 190 51 14 5.6 160

—

08/16/93 0920

—

—

—

— 190 54 14 6.1 160

—

08/23/93 0903

—

—

—

— 170 47 12 5.8 170

—

08/24/93 1800

—

—

—

— 140 37 11 4.8 180

—

08/28/93 1900

—

—

—

— 190 52 14 6.7 170

—

08/29/93 1800

—

—

—

— 180 50 14 5.1 180

—

08/30/93 1020

—

—

—

— 190 51 15 6 160

—

2S/11W-18L23LYS 08/10/93 2200

—

—

—

—

—

—

—

—

—

—

(TF-ORG at 25 ft) 08/11/93 1915

—

—

—

— 260 74 18 9.8 98

—

08/16/93 1205

—

—

—

— 170 50 12 4.2 75

—

08/23/93 0936

—

—

—

— 170 49 12 4.2 76

—

08/24/93 1800

—

—

—

—

—

—

—

—

—

—

08/30/93 1515

—

—

—

— 180 49 13 4.6 76

—

2S/11W-18L25LYS 08/10/93 2205

—

—

—

—

—

—

—

—

—

—

(TF-GRE at 10 ft)2S/11W-18L26LYS 08/10/93 2110

—

—

—

—

—

—

—

—

—

—

(TF-BLU at 5 ft) 08/23/93 0940

—

—

—

—

—

—

—

—

—

—

08/24/93 1800

—

—

—

—

—

—

—

—

—

—

2S/11W-18L27 08/10/93 1835

— 7.3 687 19.7 180 49 13 4 78 150

(PR8 at 49 ft) 08/11/93 1730

— 7.3 700 21.1 170 47 13 4.4 76 150

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 143

08/12/93 1730 — 7.3 695 20.8 180 49 13 .9 72 15008/13/93 1820 — 7.2 714 20 170 48 13 4 75 15008/16/93 1650 0.2 7.3 707 19 180 51 13 4.3 72 15008/23/93 1530 .2 7.2 700 19 180 49 14 4.5 74 14008/24/93 1305 — 7.3 696 180 50 13 4 77 14008/28/93 1350 — 7.2 718 21 190 51 14 4.1 79 14008/29/93 1305 — 7.2 717 21 180 50 14 4.1 77 15008/30/93 1450 .2 7.2 720 20 190 52 14 4.1 76 140

2S/11W-18L28 08/10/93 2145 .8 6.9 683 18.8 170 48 13 4.2 71 140(PR9 at 25 ft) 08/11/93 1500 — 7.1 695 21 170 48 13 4.8 74 140

08/12/93 1600 — 7 702 20.8 180 50 14 4.4 74 14008/13/93 1600 — 7.1 716 19.6 180 48 14 4.3 74 14008/16/93 1910 .2 7 732 19 190 53 14 4.6 72 14008/23/93 1730 .2 7 770 19 200 55 16 4.7 81 13008/24/93 1510 — 7 772 — 210 57 16 4.5 80 13008/28/93 1530 — 7.1 764 20.9 200 56 15 4.6 80 14008/29/93 1535 — 7 759 21.5 200 54 15 4.2 75 14008/30/93 1620 .2 7 753 19 200 56 15 4.6 78 140

2S/11W-18L29 08/10/93 1100 1 7 779 21 220 63 16 5.5 66 130(PR10 at 60 ft) 08/11/93 1045 — 7.3 651 19.4 160 46 12 4 75 140

08/12/93 0945 — 7.3 661 18.5 160 45 12 .1 69 14008/13/93 1120 — 7.3 669 19 160 44 12 4.1 73 14008/16/93 1035 .2 7.2 673 18 170 47 13 4.3 75 15008/23/93 1250 .2 7.2 690 18.5 170 48 13 4.7 74 14008/24/93 0720 — 7.3 694 — 170 47 13 4.3 78 14008/28/93 1000 — 7.2 727 19.9 170 48 13 4.2 77 15008/29/93 1140 — 7.2 724 19.5 180 49 14 4.5 80 15008/30/93 1250 0.2 7.2 730 19 190 52 14 4.6 79 140

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
144 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L30 08/10/93 1550 1.2 7.2 651 20.8 160 45 12 4.1 74 140 (PR11 at 36 ft) 08/11/93 1300

— 6.9 761 20.7 230 65 16 6.4 67 130

08/12/93 1200

— 6.9 758 20 240 66 17 5.8 69 130

08/13/93 1330

— 7 752 20 210 59 16 5.1 67 130

08/16/93 1450 .2 6.9 761 19 210 60 15 5.6 68 14008/23/93 1015 .2 6.9 782 18.5 220 62 16 6 73

—

08/24/93 1130

— 6.9 766 20.5 210 59 15 5.3 76 130

08/28/93 1215

— 6.9 787 20.3 210 58 15 5.1 74 140

08/29/93 0955

— 7 797 19.2 220 61 16 5.1 78 140

08/30/93 1100 .2 6.9 812 19 230 66 16 5.5 75 130

POND AT PICO 08/10/93 2200 2.8 9.7 1040 23.8 230 61 19 1.3 130 190(PR12) 08/11/93 2100

— 8 1060 24.1 230 62 19 8.8 130 170

08/12/93 2030

— 8.9 1040 24.5 220 58 19 13 120 170

08/13/93 0910

— 8.1 1070 26 230 59 19 11 120 170

08/16/93 1940

— 9.1 1030 26 230 60 19 13 120 160

08/23/93 1920 6 8.1 1040 25 230 60 20 11 120 16008/23/93 1930 2.8 7.9 1050 25.5 240 63 20 13 120 16008/23/93 1950 1 7.7 1050 25.5 230 61 19 12 130 17008/23/93 2030

— 8.9 1030 25 230 58 20 13 130

—

08/24/93 1720

— 8.7 1030 25.5 240 61 20

— 130 160

08/28/93 1745

— 8.8 1030 25.7 220 57 19 11 120 170

08/29/93 1700

— 8.8 1030 25.6 220 58 19 12 120 180

08/30/93 1745 7 8.8 1030 26 230 60 19 10 120 170

SEWAGE EFFLUENT 08/10/93 2245 1 7.3 1050 24.3 230 60 19 7.1 120 180(PR13) 08/11/93 2045

— 7.5 1090 25.5 230 59 19 8.7 120 200

08/12/93 1950

— 7.5 1100 24.4 220 58 18 1.9 110 200

08/13/93 1900

— 7.5 1130 24.2 220 57 18 10 120 210

08/16/93 2000 5 7.5 1120 26 220 58 18 13 110 21008/23/93 2010

— 7.4 1080 24.5 220 56 19 13 110 210

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(

oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
Appendixes 145

08/24/93 1750 — 7.3 1100 26.5 220 60 18 — 110 20008/28/93 1805 — 7.4 1130 27.4 220 57 18 11 110 22008/29/93 1720 — 7.4 1110 26.6 230 59 19 11 120 19008/30/93 1810 3.2 7.4 1130 28 230 61 18 11 120 210

Appendix 2A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature, 

(oC)

(00010)

Hardness, 

total

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as 

Ca)

00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

Potassium, 

dissolved 

(mg/L as K)

(00935)

Sodium, 

dissolved 

(mg/L as 

Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field,

(mg/L

as CaCO3) 

(39036)
146 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued Station name (Local identifier) Date Time Bromide, dissolved (mg/L as Br) (71870) Chloride, dissolved (mg/L as Cl) (00940) Fluoride, dissolved (mg/L as F) (00950) Silica, dissolved (mg/L as SiO2) (00955) Sulfate, dissolved (mg/L as SO4) (00945) Solids, sum of con- stituents, dissolved (mg/L) (70301) Nitrogen, ammonia, dissolved (mg/L as N) (00608) Nitrogen, nitrate, dissolved (mg/L as N) (00618) Nitrogen, nitrite plus nitrate, dissolved (mg/L as N) (00631) Nitrogen, nitrite, dissolved (mg/L as N) (00613) Phos- phorus, ortho- phos- phate, dissolved (mg/L as P) (00671) 2S/11W-18L10LYS 08/10/93 2110

—

—

— 20

—

— 0.03 0.07 0.092 0.02 0.23

(CR-RED at 50 ft) 08/11/93 1900

—

—

— 20

—

— .03 .04 .06 .02 .25

08/12/93 1655

—

—

— 21

—

— .04

— <.050 .01 .25

08/13/93 1020

—

—

— 21

—

— .01

— <.050 <.010 .26

08/16/93 1050

—

—

— 20

—

— .04

— <.050 <.010 .26

08/23/93 1054

—

—

— 19

—

— .03

— <.050 <.010 .26

08/24/93 1800

—

—

— 20

—

— .03

— .24 <.010 .26

08/28/93 1900

—

—

— 21

—

— .01

— .33 <.010 .27

08/29/93 1800

—

—

— 21

—

— .04

— .22 <.010 .29

08/30/93 1118

—

—

— 20

—

— .02

— .19 <.010 .28

2S/11W-18L11LYS 08/10/93 2135

—

—

— 28

—

— .03 .27 .29 .02 .17

(CR-ORG at 25 ft) 08/11/93 1905

—

—

— 25

—

— .03 .26 .27 .01 .17

08/12/93 1700

—

—

— 27

—

— .04 .23 .24 .01 .17

08/13/93 1025

—

—

— 27

—

— .02

— .2 <.010 .18

08/16/93 1055

—

—

— 27

—

— .03 .16 .18 .02 .17

08/23/93 1109

—

—

— 26

—

— .02

— .11 <.010 .15

08/24/93 1800

—

—

— 27

—

— .02

— <.050 .03 .04

08/28/93 1900

—

—

— 27

—

— .01

— <.050 <.010 .15

08/29/93 1800

—

—

— 27

—

— .02

— <.050 <.010 .15

08/30/93 1115

—

—

— 26

—

— .02

— <.050 <.010 .16

2S/11W-18L13LYS 08/10/93 2140

—

—

— 35

—

— 1.1 .03 .058 .03 .72

(CR-BLU at 13.5 ft) 08/11/93 1910

—

—

— 31

—

— 1.3

— <.050 <.010 .81

08/12/93 1710

—

—

— 33

—

— 1.3

— <.050 <.010 .86

08/13/93 1030

—

—

— 34

—

— 1.3

— <.050 <.010 .84

08/16/93 1100

—

—

— 34

—

— 1.4

— <0.050 <0.010 0.91

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus[See table 1 for explanation of local identifier listed below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less than value 

shown; —, no data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; TF, Teflon lysimeter; MLS, multilevel sampler]
Appendixes 147

08/23/93 1112 — — — 35 — — 1.4 — <.050 <.010 .9608/24/93 1800 — — — 34 — — 1.3 — <.050 <.010 .9408/28/93 1900 — — — 34 — — 1.4 — <.050 <.010 .9808/29/93 1800 — — — 35 — — 1.5 — <.050 <.010 108/30/93 1120 — — — — — — 1.5 — <.050 <.010 1

2S/11W-18L14A 08/10/93 2110 0.1 83 0.4 22 120 — .34 0.59 .61 .02 .41(MLS20) 08/11/93 2000 — — — 22 — — .23 .67 .69 .02 .38

08/12/93 2000 — — — 22 — — .2 .83 .85 .02 .3308/13/93 1920 — — — 21 — — .2 1.08 1.1 .02 .3308/16/93 1855 — — — 21 — — .2 1.27 1.3 .03 .3308/23/93 1900 — — — 22 — — .18 1.27 1.3 .03 .3508/24/93 1700 — — — 22 — — .17 .94 .98 .04 .3208/28/93 1730 — — — 21 — — .16 .71 .74 .03 .3308/29/93 1635 — — — 21 — — .15 .39 .41 .02 .308/30/93 1730 — — — 22 — — .14 .22 .23 .01 .31

2S/11W-18L14B 08/10/93 2040 — — — 22 — — .9 1.18 1.2 .02 .69(MLS19) 08/11/93 1930 — — — 22 — — .27 .54 .56 .02 .44

08/12/93 1920 — — — 24 — — 1.1 1.19 1.2 .01 .8408/13/93 1845 — — — 23 — — 1.1 .92 .93 .01 .8208/16/93 1818 — — — 23 — — 1.1 .22 .23 .01 .8908/23/93 1830 — — — 23 — — — — — — —08/24/93 1650 — — — 24 — — .96 .62 <.010 .7608/28/93 1715 — — — 22 — — .94 .44 .45 .01 .8908/29/93 1620 .14 96 .4 23 140 558 .84 1.19 1.2 .01 .8708/30/93 1715 — — — 23 — — .87 .32 .33 .01 .91

2S/11W-18L14C 08/10/93 2005 — — — 22 — — 1.1 2.47 2.5 .03 .82(MLS18) 08/11/93 1900 — — — 23 — — 1.2 1.68 1.7 0.02 0.89

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
148 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/12/93 1845

—

—

— 23

—

— 1.3 .78 .8 .02 .97

08/13/93 1800

—

—

— 23

—

— 1.2 .36 .38 .02 .89

08/16/93 1745

—

—

— 23

—

— 1.2

— <.050 <.010 .99

08/23/93 1815

—

—

— 23

—

— 1.2

— <.050 <.010 .92

08/24/93 1615

—

—

— 24

—

— 1.2

— .052 <.010 .89

08/28/93 1655

—

—

— 22

—

— 1.1

— .09 <.010 1

08/29/93 1600

—

—

— 22

—

— .97

— .077 <.010 .96

08/30/93 1630

—

—

— 23

—

— .98

— .074 <.010 .99

2S/11W-18L14D 08/10/93 1930

—

—

— 24

—

— 1.6 1.19 1.2 .01 1.1

(MLS17) 08/11/93 1830

—

—

—

—

—

— 1.6

— .7 <.010 1.1

08/12/93 1800

—

—

— 23

—

— 1.7 .29 .3 .01 1.2

08/13/93 1745

—

—

— 24

—

— 1.6

— <.050 <.010 1.1

08/16/93 1705

—

—

— 24

—

— 1.5

— <.050 <.010 1.2

08/23/93 1800

—

—

— 23

—

— 1.6

— <.050 <.010 1.1

08/24/93 1550

—

—

— 23

—

— 1.4

— <.050 <.010 1

08/28/93 1640

—

—

— 23

—

— 1.5

— .096 <.010 1.3

08/29/93 1540

—

—

— 23

—

— 1.4

— .063 <.010 1.3

08/30/93 1600

—

—

— 23

—

— 1.4

— <.050 <.010 1.3

2S/11W-18L14E 08/10/93 1915

—

—

— 23

—

— .82

— 1.2 <.010 .67

(MLS16) 08/11/93 1745

—

—

— 23

—

— .88

— .72 <.010 .69

08/12/93 1700

—

—

— 23

—

— .94

— .22 <.010 .72

08/13/93 1720

—

—

— 23

—

— .91

— <.050 <.010 .76

08/16/93 1620

—

—

— 23

—

— 1.2

— .063 <.010 .94

08/23/93 1710 0.13 110 0.4 23 170 600 1 — <.050 <.010 .8108/24/93 1525

—

—

— 23

—

— .75

— <.050 <.010 .64

08/28/93 1620

—

—

— 22

—

— .97

— .056 <.010 .9

08/29/93 1510

—

—

— 22

—

— 0.99

— <0.050 <0.010 0.91

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 149

08/30/93 1540 — — — 23 — — .96 — <.050 <.010 .88

2S/11W-18L14F 08/10/93 1755 — — — 21 — — .63 — 2.2 <.010 .47(MLS15) 08/11/93 1700 — — — — — — .67 — 1.2 <.010 .49

08/12/93 1620 — — — 22 — — .76 — .052 <.010 .5308/13/93 1700 — — — 21 — — .74 — <.050 <.010 .5208/16/93 1530 — — — 21 — — .79 — <.050 <.010 .4808/23/93 1700 — — — 22 — — .83 — <.050 <.010 .4808/24/93 1450 — — — 22 — — .8 — <.050 <.010 .4708/28/93 1600 — — — 21 — — .77 — <.050 <.010 .4908/29/93 1450 — — — 21 — — .8 — <.050 <.010 .5308/30/93 1440 — — — 22 — — .74 — <.050 <.010 .48

2S/11W-18L14G 08/10/93 1710 — — — 21 — — .76 — .58 <.010 .62(MLS14) 08/11/93 1610 — — — 22 — — .8 — .34 <.010 .64

08/12/93 1500 — — — 21 — — .92 — <.050 <.010 .6508/13/93 1645 — — — 21 — — 1.1 — <.050 <.010 .6808/16/93 1550 — — — 21 — — 1.1 — .14 <.010 .6908/23/93 1630 — — — 21 — — 1.1 — <.050 <.010 .6408/24/93 1430 — — — 22 — — .76 — <.050 <.010 .4508/28/93 1500 — — — 20 — — .9 — <.050 <.010 .6308/29/93 1250 — — — 20 — — .85 — <.050 <.010 .6108/30/93 1430 — — — 21 — — .92 — <.050 <.010 .7

2S/11W-18L14H 08/10/93 1625 — — — 20 — — .92 — <.050 <.010 .64(MLS13) 08/11/93 1545 — — — 21 — — .87 — <.050 <.010 .64

08/12/93 1445 — — — 20 — — .89 — <.050 <.010 .6408/13/93 1620 — — — 20 — — .86 — <.050 <.010 .6308/16/93 1430 — — — 21 — — .78 — .25 <.010 .7308/23/93 1600 — — — 19 — — 0.66 — <0.05 <0.01 0.68

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
150 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/24/93 1315

—

—

— 20

—

— .6

— <.050 <.010 .64

08/28/93 1515

—

—

— 19

—

— .6

— <.050 <.010 .65

08/29/93 1235

—

—

— 20

—

— .57

— <.050 <.010 .61

08/30/93 1310

—

—

— 19

—

— .56

— <.050 <.010 .59

2S/11W-18L14I 08/10/93 1525

—

—

— 20

—

— .45

— <.050 <.010 .54

(MLS12) 08/11/93 1520

—

—

—

—

—

— .49

— <.050 <.010 .56

08/12/93 1315

—

—

— 20

—

— .49

— .059 <.010 .56

08/13/93 1530 0.12 120 0.5 20 140 590 .58

— <.050 <.010 .63

08/16/93 1250

—

—

— 21

—

— .49

— .13 <.010 .71

08/23/93 1520

—

—

— 20

—

— .49

— <.050 <.010 .72

08/24/93 1220 .15 110 .6 20 170 600 .42

— <.050 <.010 .728

08/28/93 1335

—

—

— 19

—

— .37

— <.050 <.010 .65

08/29/93 1220

—

—

— 19

—

— .39

— <.050 <.010 .65

08/30/93 1230

—

—

— 20

—

— .33

— <.050 <.010 .62

2S/11W-18L14J 08/10/93 1500

—

—

— 20

—

— .41

— <.050 <.010 .54

(MLS11) 08/11/93 1240 .15 100 .3 20 180 588 .41

— .43 <.010 .53

08/12/93 1250

—

—

— 20

—

— .41

— .3 <.010 .57

08/13/93 1500

—

—

— 22

—

— .46

— <.050 <.010 .71

08/16/93 1245

—

—

— 21

—

— .57

— <.050 <.010 1.1

08/23/93 1500

—

—

— 20

—

— .59

— <.050 <.010 .84

08/24/93 1200

—

—

— 21

—

— .58

— <.050 <.010 .81

08/28/93 1315

—

—

— 19

—

— .31

— <.050 <.010 .65

08/29/93 1200

—

—

— 19

—

— .28

— <.050 <.010 .63

08/30/93 1215

—

—

— 20

—

— .25

— <.050 <.010 .61

2S/11W-18L14K 08/10/93 1415

—

—

— 21

—

— 1.7

— <.050 <.010 .92

(MLS10) 08/11/93 1210

—

—

— 21

—

— .8

— <.050 <.010 .7

08/12/93 1220

—

—

— 22

—

— 0.94

— 0.97 <0.010 0.81

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 151

08/13/93 1300 — — — 24 — — .89 — <.050 <.010 .9408/16/93 1200 — — — 22 — — 1.1 — <.050 <.010 1.508/23/93 1230 — — — 24 — — 1.5 — .27 <.010 1.308/24/93 1105 — — — 24 — — 1.5 — .25 <.010 1.208/28/93 1250 — — — 21 — — .84 — .7 <.010 .9108/29/93 1125 — — — 21 — — .74 — .48 <.010 .8308/30/93 1150 — — — 21 — — .63 — .3 <.010 .8

2S/11W-18L14L 08/10/93 1345 — — — 19 — — .68 — .064 <.010 .61(MLS9) 08/11/93 1115 — — — 22 — — 1.5 — <.050 <.010 .95

08/12/93 1130 — — — 22 — — 2.1 — 2 <.010 1.108/13/93 1230 — — — 24 — — 2.1 — <.050 <.010 1.208/16/93 1130 — — — 22 — — 2.1 — <.050 <.010 1.808/23/93 1210 — — — 24 — — 2.1 — .22 <.010 1.508/24/93 1045 — — — 25 — — 2.1 — .2 <.010 1.508/28/93 1230 — — — 25 — — 2 — 1.1 <.010 1.408/29/93 1105 — — — 25 — — 2 — .95 <.010 1.208/30/93 1130 0.17 110 0.4 24 170 655 2 — 2.9 <.010 1.3

2S/11W-18L14M 08/10/93 1230 — — — 23 — — 2.2 — .26 <.010 1.3(MLS8) 08/11/93 1030 — — — 24 — — 2.3 — .18 <.010 1.4

08/12/93 1100 — — — 25 — — 2.3 — .51 <.010 1.508/13/93 1150 — — — 24 — — 2.3 — .057 <.010 1.508/16/93 1100 — — — 24 — — 2.2 — <.050 <.010 1.408/23/93 1145 — — — 24 — — 2.2 — <.050 <.010 1.508/24/93 1020 — — — 25 — — 2.3 — <.050 <.010 1.508/28/93 1120 — — — 24 — — 2 — .1 <.010 1.608/29/93 1050 .1 120 .6 25 140 634 1.9 — 2 <.010 1.608/30/93 1050 — — — 24 — — 1.6 — 0.093 <0.010 1.4

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
152 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14N 08/10/93 1115 0.07 130 0.8 25 110 652 3.5

— .15 <.010 1.9

(MLS7) 08/11/93 1000

—

—

— 25

—

— 3.7

— <.050 <.010 2.1

08/12/93 1030 .05 140 .7 26 82 631 3.8

— <.050 <.010 2.1

08/13/93 1040

—

—

— 26

—

— 3.6

— <.050 <.010 2

08/16/93 1015

—

—

— 26

—

— 3.5

— <.050 <.010 2

08/23/93 1100

—

—

— 25

—

— 3.3

— <.050 <.010 1.8

08/24/93 0930

—

—

— 25

—

— 3.5

— <.050 <.010 2

08/28/93 1050

—

—

— 24

—

— 2.7

— <.050 <.010 2.3

08/29/93 1030

—

—

— 24

—

— 2.4

— <.050 <.010 2.4

08/30/93 1030

—

—

— 25

—

— 2.3

— <.050 <.010 2.5

2S/11W-18L14O 08/10/93 1010

—

—

— 24

—

— 3.4

— .064 <.010 1.9

(MLS6) 08/11/93 0930

—

—

— 25

—

— 3.5

— <.050 <.010 2

08/12/93 0930

—

—

— 25

—

— 3.4

— <.050 <.010 2.1

08/13/93 1015

—

—

— 28

—

— 3.4

— <.050 <.010 2

08/16/93 1000

—

—

— 26

—

— 3.3

— <.050 <.010 2

08/23/93 1050

—

—

— 24

—

— 3 — <.050 <.010 1.7

08/24/93 0850

—

—

— 24

—

— 3.1

— <.050 <.010 1.8

08/28/93 1020 .08 130 .7 25 120 630 2.7

— .051 <.010 2.1

08/29/93 1015

—

—

— 24

—

— 2.6

— <.050 <.010 2.2

08/30/93 1000

—

—

— 24

—

— 2.3

— <.050 <.010 2.1

2S/11W-18L14P 08/10/93 0846

—

—

— 25

—

— 3.3

— <.050 <.010 2

(MLS5) 08/11/93 0900

—

—

— 26

—

— 3.3

— <.050 <.010 2.2

08/12/93 0900

—

—

— 26

—

— 3.2

— <.050 <.010 2.2

08/13/93 0845

—

—

— 27

—

— 3.6

— <.050 <.010 2.3

08/16/93 0900 .04 130 .8 29 120 644 3.3

— <.050 <.010 2.2

08/23/93 0945

—

—

— 27

—

— 3.1

— <.050 <.010 2.2

08/24/93 0830

—

—

— 27

—

— 3.4

— <0.050 <0.010 2.2

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 153

08/28/93 0930 — — — 26 — — 2.9 — <.050 <.010 2.408/29/93 0930 — — — 26 — — 3 — <.050 <.010 2.508/30/93 0920 — — — 26 — — 2.8 — <.050 <.010 2.5

2S/11W-18L14Q 08/10/93 0845 — — — 27 — — 3.2 — <.050 <.010 2.5(MLS4) 08/11/93 0845 — — — 27 — — 3.3 — <.050 <.010 2.7

08/12/93 0845 — — — 31 — — 3.2 — <.050 <.010 2.708/13/93 0810 — — — 30 — — 3 — <.050 <.010 2.708/16/93 0845 — — — 28 — — 2.8 — <.050 <.010 2.708/23/93 0920 — — — 30 — — 2.8 — <.050 <.010 2.708/24/93 0815 0.07 130 0.8 31 120 641 2.8 — <.050 <.010 2.508/28/93 0930 — — — 29 — — 2.8 — <.050 <.010 2.808/29/93 0910 — — — 28 — — 2.6 — <.050 <.010 2.808/30/93 0820 — — — 28 — — 2.9 — <.050 <.010 2.8

2S/11W-18L15LYS 08/10/93 1955 — — — 21 — — .04 0.54 .65 .11 .02(SS-RED at 49 ft) 08/11/93 1815 — — — 20 — — .02 .52 .63 .11 <.010

08/12/93 1550 — — — 22 — — .04 .44 .49 .05 .0108/13/93 0905 — — — 21 — — .02 .37 .43 .06 .0108/16/93 0750 — — — 22 — — .04 .27 .32 .05 .0208/23/93 0850 — — — 20 — — .02 — <.050 <.010 .0208/24/93 1800 — — — — — .02 .13 .16 .03 .0108/28/93 1900 — — — 21 — — .03 — <.050 .01 .0208/29/93 1800 — — — 21 — — .03 .04 .056 .02 .0208/30/93 0900 — — — 21 — — .03 .05 .069 .02 .02

2S/11W-18L16LYS 08/10/93 2015 — — — 29 — — .03 .29 .49 .2 .09(SS-ORG at 25 ft) 08/11/93 1835 — — — 24 — — .03 — <.050 .02 .13

08/12/93 1555 — — — 24 — — .05 — <.050 .03 .1408/13/93 0915 — — — 24 — — 0.04 — <0.050 0.02 0.12

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
154 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 0755

—

—

— 27

—

— .04

— <.050 <.010 .07

08/23/93 0851 0.12 59 0.3 25 120

— .01

— <.050 <.010 .05

08/24/93 1800

—

—

— 22

—

— .02

— <.050 <.010 .15

08/28/93 1900

—

—

— 24

—

— .04

— <.050 <.010 .04

08/29/93 1800

—

—

— 22

—

— .02

— <.050 .02 .05

08/30/93 0900 .14 61 .3 23 120

— .02

— <.050 .02 .06

2S/11W-18L17LYS 08/10/93 2025

—

—

— 42

—

— .07 0.08 .21 .13 .33

(SS-YEL at 15 ft) 08/11/93 1830 .13 77 .3 35 130

— .29

— <.050 <.010 .02

08/12/93 1610

—

—

— 25

—

— .42 .03 .12 .09 .32

08/13/93 0920

—

—

— 24

—

— .46 .01 .07 .06 .3

08/16/93 0800

—

—

— 27

—

— .4 .03 .1 .07 .28

08/23/93 0853

—

—

— 23

—

— .36

— <.050 <.010 .25

08/24/93 1800

—

—

— 21

—

— .1

— <.050 <.010 .23

08/28/93 1900

—

—

— 24

—

— .48

— <.050 <.010 .22

08/29/93 1800

—

—

— 23

—

— .39

— <.050 <.010 .25

08/30/93 0900

—

—

— 25

—

— .38

— <.050 <.010 .24

2S/11W-18L18LYS 08/10/93 2100

—

—

—

—

—

— .03

— 1.3 <.010 .54

(SS-GRE at 10 ft) 08/11/93 1840

—

—

— 25

—

— 1 — <.050 <.010 .62

08/12/93 1615

—

—

— 24

—

— 1.1

— <.050 <.010 .59

08/13/93 0925

—

—

— 24

—

— 1.2

— <.050 <.010 .55

08/16/93 0805

—

—

— 26

—

— 1.4

— <.050 <.010 .56

08/23/93 0854

—

—

— 25

—

— .86

— <.050 <.010 .58

08/24/93 1800

—

—

—

—

—

— .25

— <.050 <.010 .56

08/28/93 1900

—

—

— 24

—

— .3

— <.050 <.010 .58

08/29/93 1800

—

—

— 23

—

— .56

— <.050 <.010 .53

08/30/93 0900

—

—

— 23

—

— .51

— <.050 <.010 .55

2S/11W-18L19LYS 08/10/93 2110

—

—

—

—

—

— 0.16

— <0.050 0.01 0.92

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 155

(SS-BLU at 5 ft) 08/11/93 1845 — — — 130 — — .1 — <.050 .02 .97

08/12/93 1620 — — — 97 — — .13 — <.050 .03 .9408/13/93 0930 — — — 55 — — .15 — <.050 <.010 .7708/16/93 0810 — — — 53 — — — — — — —08/23/93 0855 — — — 58 — — .13 — <.050 .02 .8308/24/93 1800 — — — 54 — — .25 — <.050 <.010 .7808/28/93 1900 — — — 51 — — .13 — <.050 <.010 .8708/29/93 1800 — — — — — — .27 — <.050 <.010 .7508/30/93 0900 — — — 47 — — .28 — <.050 <.010 .73

2S/11W-18L20LYS 08/10/93 2107 — — — — — — 1.5 0.06 .081 .02 .78(CR-YEL at 15 ft) 08/11/93 1855 — — — 19 — — 1.3 — <.050 <.010 .76

08/12/93 1645 — — — 21 — — 1.4 — <.050 <.010 .7408/13/93 0940 — — — 19 — — 1.4 — <.050 <.010 .7808/16/93 0925 — — — 21 — — 1.3 — <.050 <.010 .7708/23/93 0902 — — — 19 — — 1.1 — <.050 <.010 .808/24/93 1800 — — — 19 — — .67 — <.050 <.010 .7308/28/93 1900 — — — 20 — — .6 — <.050 <.010 .7308/29/93 1800 — — — 20 — — .53 — <.050 <.010 .6708/30/93 1022 — — — — — — .51 — <.050 <.010 .66

2S/11W-18L21LYS 08/10/93 2145 — — — — — — .36 — .059 <.010 1.3(CR-GRE at 9 ft) 08/11/93 1850 — — — 69 — — .91 — <.050 <.010 .97

08/12/93 1635 — — — 58 — — 1.1 — <.050 <.010 .9608/13/93 0935 — — — 57 — — 1 — <.050 <.010 .9808/16/93 0920 — — — 60 — — 1.1 — <.050 <.010 108/23/93 0903 — — — 68 — — .95 — <.050 <.010 1.108/24/93 1800 — — — 71 — — .79 — <.050 <.010 1.108/28/93 1900 — — — 68 — — 0.96 — <0.050 <0.010 1.1

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
156 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/29/93 1800

—

—

— 70

—

— .87

— <.050 <.010 1.1

08/30/93 1020

—

—

—

—

—

— .97

— <.050 <.010 1

2S/11W-18L23LYS 08/10/93 2200

—

—

—

—

—

— .03 1.44 1.6 .16 .07

(TF-ORG at 25 ft) 08/11/93 1915

—

—

— 24

—

— .02 1.38 1.4 .02 .07

08/16/93 1205

—

—

— 23

—

— .03

— 1.8 <.010 .07

08/23/93 0936

—

—

— 21

—

— .03

— 1.1 <.010 .07

08/24/93 1800

—

—

—

—

—

— .02

— .89 <.010 .08

08/30/93 1515

—

—

— 21

—

— .02

— .63 <.010 .08

2S/11W-18L25LYS 08/10/93 2205

—

—

—

—

—

— .03 .8 .86 .06 1.7

(TF-GRE at 10 ft)2S/11W-18L26LYS 08/10/93 2110

—

—

—

—

—

— .04 1.77 2.7 .93 .44

(TF-BLU at 5 ft) 08/23/93 0940

—

—

—

—

—

— .05 .13 .25 .12 .41

08/24/93 1800

—

—

—

—

—

— .02 .22 .26 .04 .42

2S/11W-18L27 08/10/93 1835

—

—

— 21

—

— .03

— .7 <.010 .15

(PR8 at 49 ft) 08/11/93 1730

—

—

— 21

—

— .02

— .65 <.010 .15

08/12/93 1730

—

—

— 20

—

— .04

— .62 <.010 .15

08/13/93 1820

—

—

— 21

—

— .03

— .56 <.010 .15

08/16/93 1650

—

—

— 20

—

— .03

— .56 <.010 .14

08/23/93 1530

—

—

— 21

—

— .02

— .59 <.010 .15

08/24/93 1305

—

—

— 21

—

— .02

— .59 <.010 .16

08/28/93 1350

—

—

— 21

—

— .03

— .6 <.010 .15

08/29/93 1305

—

—

— 20

—

— .03

— .61 <.010 .16

08/30/93 1450

—

—

— 21

—

— .02

— .63 <.010 .16

2S/11W-18L28 08/10/93 2145

—

—

— 20

—

— .03

— .82 <.010 .06

(PR9 at 25 ft) 08/11/93 1500

—

—

— 21

—

— .02

— .8 <.010 .05

08/12/93 1600 0.14 57 0.3 21 120 426 .03

— .77 <.010 .06

08/13/93 1600

—

—

— 20

—

— 0.03

— 0.7 <0.010 0.07

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 157

08/16/93 1910 — — — 20 — — .03 — .57 <.010 .0608/23/93 1730 — — — 21 — — .04 — .46 <.010 .0608/24/93 1510 — — — 22 — — .02 — .43 <.010 .0508/28/93 1530 0.15 77 0.3 21 140 481 .03 — .38 <.010 .0508/29/93 1535 — — — 21 — — .22 2.67 3 .33 1.408/30/93 1620 — — — 21 — — .03 — .38 <.010 .05

2S/11W-18L29 08/10/93 1100 .16 82 .4 20 140 476 .04 — .18 <.010 .6(PR10 at 60 ft) 08/11/93 1045 — — — 21 — — .02 — .34 <.010 .09

08/12/93 0945 — — — 20 — — .05 — .36 <.010 .108/13/93 1120 — — — 20 — — .03 — .34 <.010 .108/16/93 1035 .12 55 .4 21 110 416 .04 — .36 <.010 .0908/23/93 1250 — — — 20 — — .02 — .39 <.010 .0908/24/93 0720 — — — 21 — — .03 — .36 <.010 .108/28/93 1000 — — — 20 — — .02 — .24 <.010 .0908/29/93 1140 — — — 20 — — .03 — .25 <.010 .108/30/93 1250 — — — 21 — — .02 — .23 .01 .1

2S/11W-18L30 08/10/93 1550 — — — 21 — — .03 — .35 <.010 .1(PR11 at 36 ft) 08/11/93 1300 — — — 20 — — .02 — .26 <.010 .61

08/12/93 1200 — — — 21 — — .03 — .32 <.010 .5908/13/93 1330 — — — 20 — — .03 — .34 <.010 .5908/16/93 1450 — — — 20 — — .04 — 2 <.010 .5708/23/93 1015 — — — 20 — — .01 — 1.6 <.010 .5508/24/93 1130 — — — 21 — — .03 — 1.2 <.010 .5608/28/93 1215 — — — 20 — — .02 — .46 <.010 .5508/29/93 0955 — — — 20 — — .03 — .36 <.010 .5508/30/93 1100 — — — 20 — — .02 — .31 <.010 .52

POND AT PICO 08/10/93 2200 — — — 23 — — 0.05 — <0.050 <0.010 0.2

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
158 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California (PR12) 08/11/93 2100

—

—

— 22

—

— 1.4 3.9 5.2 1.3 1.9

08/12/93 2030

—

—

— 21

—

— .34 3.8 5.3 1.5 1.2

08/13/93 0910

—

—

— 21

—

— .35 3.5 5.3 1.8 1.8

08/16/93 1940

—

—

— 21

—

— .2 3.8 6.5 2.7 1.2

08/23/93 1920

—

—

— 20

—

— .18 4.94 5.2 .26 1.7

08/23/93 1930

—

—

— 21

—

— .35 5.04 5.3 .26 1

08/23/93 1950 0.06 130 0.6 21 150 652 .52 4.57 4.8 .23 1.708/23/93 2030

—

—

— 20

—

— .3 4.9 5.2 .3 1.4

08/24/93 1720

—

—

— 22

—

— .19 4.56 4.8 .24 1.5

08/28/93 1745

—

—

— 20

—

— .19 3.09 3.4 .31 1.4

08/29/93 1700

—

—

— 20

—

— .03

— .39 <.010 .05

08/30/93 1745

—

—

— 21

—

— .28 2.38 2.7 .32 1.4

SEWAGE EFFLUENT 08/10/93 2245

—

—

— 20

—

— 5.3 5 6.6 1.6 2.2

(PR13) 08/11/93 2045 .05 120 .7 20 150 719 12 15.3 17 1.7 3.5

08/12/93 1950

—

—

— 19

—

— 12 3.3 5.3 2 2.1

08/13/93 1900

—

—

— 20

—

— 12 3.9 6.1 2.2 2

08/16/93 2000

—

—

— 20

—

— 13 2.8 4.6 1.8 3.6

08/23/93 2010

—

—

— 20

—

— 13 3.1 4.7 1.6 3.8

08/24/93 1750

—

—

— 21

—

— 14 3.2 5 1.8 2.3

08/28/93 1805

—

—

— 20

—

— 16 1.7 3.6 1.9 2

08/29/93 1720

—

—

— 20

—

— 11 4.7 6.4 1.7 1.5

08/30/93 1810

—

—

— 21

—

— 16 2.1 3.9 1.8 2.1

Appendix 2B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, bromide–phosphorus—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L 

as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

(70301)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as 

N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as 

N)

(00618)

Nitrogen, 

nitrite 

plus 

nitrate, 

dissolved 

(mg/L as 

N)

(00631)

Nitrogen, 

nitrite, 

dissolved

(mg/L as 

N)

(00613)

Phosphorus, 

orthophosphate, 

dissolved 

(mg/L as 

P)

(00671)
Appendixes 159

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)

2S/11W-18L10LYS 08/10/93 2110 13 100 <0.5 <1 <1 2(CR-RED at 50 ft) 08/11/93 1900 15 100 <.5 <1 <1 2

08/12/93 1655 13 110 <.5 <1 <1 208/13/93 1020 — 110 <.5 <1 <1 208/16/93 1050 15 110 <.5 <1 <1 208/23/93 1054 14 100 <.5 <1 <1 308/24/93 1800 15 97 <.5 <1 <5 308/28/93 1900 15 100 <.5 <1 <1 308/29/93 1800 15 100 <.5 <1 <1 208/30/93 1118 15 110 <.5 <1 <1 3

2S/11W-18L11LYS 08/10/93 2135 — 81 <.5 <1 <1 <1(CR-ORG at 25 ft) 08/11/93 1905 6 85 <.5 <1 <1 <1

08/12/93 1700 5 89 <.5 <1 <1 <108/13/93 1025 6 88 <.5 <1 <1 <108/16/93 1055 6 90 <.5 <1 <1 <108/23/93 1109 5 92 <.5 <1 <1 108/24/93 1800 5 90 <.5 <1 <5 <308/28/93 1900 5 96 <.5 <1 <1 108/29/93 1800 5 96 <.5 <1 <1 <108/30/93 1115 5 93 <.5 <1 <1 1

2S/11W-18L13LYS 08/10/93 2140 — 120 <.5 <1 <1 5(CR-BLU at 13.5 ft) 08/11/93 1910 — 120 <.5 <1 1 3

08/12/93 1710 14 120 <.5 <1 <1 408/13/93 1030 — 130 <.5 <1 <1 408/16/93 1100 17 120 <.5 <1 <1 408/23/93 1112 17 120 <.5 <1 <1 408/24/93 1800 16 120 <.5 <1 <5 <308/28/93 1900 — 120 <.5 <1 250 5

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt[See table 1 for explanation of local identifier listed under station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value 

shown; —, no data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; TF, Teflon lysimeter; MLS, multilevel sampler]
160 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/29/93 1800 17 120 <0.5 1 <1 3 08/30/93 1120

—

—

— <1 <1 4

2S/11W-18L14A 08/10/93 2110 10 140 <.5 1 <.5 <3(MLS20) 08/11/93 2000 6 130 <.5 <1 <.5 <3

08/12/93 2000 6 140 <.5 <1 <.5 <308/13/93 1920 5 140 <.5 <1 <.5 <308/16/93 1855 7 150 <.5 <1 <.5 <308/23/93 1900 8 170 <.5 <1 <.5 <308/24/93 1700 6 150 <.5 1 <.5 <308/28/93 1730 8 150 <.5 <1 <.5 <308/29/93 1635 7 140 <.5 <1 <.5 <308/30/93 1730 6 150 <.5 <1 <.5 <3

2S/11W-18L14B 08/10/93 2040 9 170 <.5 <1 <.5 <3(MLS19) 08/11/93 1930 10 140 <.5 <1 <.5 <3

08/12/93 1920 10 180 <.5 <1 <.5 <308/13/93 1845 9 170 <.5 <1 <.5 <308/16/93 1818 11 150 <.5 1 <.5 <308/23/93 1830 10 160 <.5 <1 <.5 <308/24/93 1650 10 170 <.5 <1 <.5 <308/28/93 1715 11 160 <.5 1 <.5 <308/29/93 1620 10 160 <.5 1 <.5 <308/30/93 1715 10 160 <.5 <1 <.5 <3

2S/11W-18L14C 08/10/93 2005 9 170 <.5 1 <.5 <3(MLS18) 08/11/93 1900 9 170 <.5 <1 <.5 <3

08/12/93 1845 11 160 <.5 <1 <.5 308/13/93 1800 10 160 <.5 <1 <.5 <308/16/93 1745 13 150 <.5 <1 <.5 <308/23/93 1815 11 160 <.5 <1 <.5 <308/24/93 1615 12 160 <.5 <1 <.5 <308/28/93 1655 11 160 <.5 <1 <.5 <308/29/93 1600 11 160 <.5 <1 <5 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 161

08/30/93 1630 12 160 <0.5 1 <5 <3

2S/11W-18L14D 08/10/93 1930 12 160 <.5 <1 <5 <3(MLS17) 08/11/93 1830 — — — — — —

08/12/93 1800 13 150 <.5 2 <5 508/13/93 1745 14 160 <.5 <1 <5 <308/16/93 1705 16 150 <.5 <1 <5 <308/23/93 1800 13 160 <.5 <1 <5 308/24/93 1550 14 160 <.5 <1 <5 <308/28/93 1640 14 160 <.5 <1 <5 <308/29/93 1540 15 160 <.5 <1 <5 <308/30/93 1600 15 150 <.5 <1 <5 <3

2S/11W-18L14E 08/10/93 1915 8 160 <.5 <1 <5 <3(MLS16) 08/11/93 1745 8 160 <.5 1 <5 <3

08/12/93 1700 9 160 <.5 <1 <5 <308/13/93 1720 11 160 <.5 <1 <5 <308/16/93 1620 15 160 <.5 <1 <5 <308/23/93 1710 11 170 <.5 2 <5 <308/24/93 1525 10 190 <.5 <1 <5 <308/28/93 1620 11 170 <.5 <1 <5 <308/29/93 1510 11 170 <.5 <1 <5 <308/30/93 1540 11 180 <.5 <1 <5 <3

2S/11W-18L14F 08/10/93 1755 9 170 <.5 <1 <5 <3(MLS15) 08/11/93 1700 — — — — — —

08/12/93 1620 13 180 <.5 <1 <5 <308/13/93 1700 15 180 <.5 <1 <5 <308/16/93 1530 14 200 <.5 <1 <5 <308/23/93 1700 9 210 <.5 <1 <5 <308/24/93 1450 10 210 <.5 2 <5 <308/28/93 1600 10 210 <.5 <1 <5 <308/29/93 1450 10 210 <.5 <1 <5 <308/30/93 1440 9 210 <.5 1 <5 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
162 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14G 08/10/93 1710 10 160 <0.5 <1 <5 <3 (MLS14) 08/11/93 1610 10 170 <.5 <1 <5 <3 08/12/93 1500 13 160 <.5 <1 <5 <3 08/13/93 1645 11 180 <.5 <1 <5 <3 08/16/93 1550 11 190 <.5 <1 <5 <3 08/23/93 1630 12 190 <.5 <1 <5 <3 08/24/93 1430 9 210 <.5 <1 <5 <3 08/28/93 1500 10 180 <.5 <1 <5 <3 08/29/93 1250 10 190 <.5 <1 <5 <3 08/30/93 1430 11 190 <.5 <1 <5 <3 2S/11W-18L14H 08/10/93 1625 9 170 <.5 1 <5 <3 (MLS13) 08/11/93 1545 10 180 <.5 <1 <5 <3 08/12/93 1445 10 180 <.5 1 <5 <3 08/13/93 1620 10 190 <.5 <1 <5 <3 08/16/93 1430 9 170 <.5 <1 <5 <3 08/23/93 1600 9 180 <.5 <1 <5 <3 08/24/93 1315 10 180 <.5 <1 <5 <3 08/28/93 1515 9 170 <.5 <1 <5 <3 08/29/93 1235 9 180 <.5 <1 <5 <3 08/30/93 1310 9 180 <.5 1 <5 <3 2S/11W-18L14I 08/10/93 1525 7 160 <.5 <1 <5 <3 (MLS12) 08/11/93 1520

—

—

—

—

—

—

08/12/93 1315 7 160 <.5 1 <5 <308/13/93 1530 9 160 <.5 1 <5 308/16/93 1250 8 150 <.5 <1 <5 <308/23/93 1520 9 160 <.5 <1 <5 <308/24/93 1220 9 160 <.5 <1 <5 <308/28/93 1335 7 160 <.5 <1 <5 <308/29/93 1220 8 160 <.5 <1 <5 <308/30/93 1230 7 160 <.5 <1 <5 <3

2S/11W-18L14J 08/10/93 1500 7 150 <.5 <1 <5 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 163

(MLS11) 08/11/93 1240 6 150 <0.5 <1 <5 <3

08/12/93 1250 5 150 <.5 <1 <5 <308/13/93 1500 10 140 <.5 <1 <1 <308/16/93 1245 11 130 <.5 <1 <1 <308/23/93 1500 8 150 <.5 <1 <1 408/24/93 1200 8 150 <.5 <1 <1 <308/28/93 1315 6 150 <.5 <1 <1 <308/29/93 1200 6 150 <.5 <1 <1 <308/30/93 1215 6 160 <.5 <1 <1 <3

2S/11W-18L14K 08/10/93 1415 8 160 <.5 <1 <1 <3(MLS10) 08/11/93 1210 7 160 <.5 <1 <1 <3

08/12/93 1220 6 160 <.5 <1 <1 <308/13/93 1300 11 140 <.5 <1 <1 <308/16/93 1200 13 130 <.5 <1 <1 <308/23/93 1230 9 150 <5 <1 <1 <308/24/93 1105 10 150 <.5 <1 <1 <308/28/93 1250 6 160 <.5 <1 <1 <308/29/93 1125 6 160 <.5 <1 <1 <308/30/93 1150 6 160 <.5 1 <1 <3

2S/11W-18L14L 08/10/93 1345 6 150 <.5 <1 <1 <3(MLS9) 08/11/93 1115 8 160 <.5 <1 <1 <3

08/12/93 1130 7 160 <.5 <1 <1 <308/13/93 1230 12 140 <.5 <1 <1 <308/16/93 1130 15 130 <.5 <1 <1 308/23/93 1210 10 140 <.5 <1 <1 <308/24/93 1045 10 140 <.5 <1 <1 308/28/93 1230 8 160 <.5 <1 <1 <308/29/93 1105 8 170 <.5 <1 <1 <308/30/93 1130 7 170 <.5 <1 <1 <3

2S/11W-18L14M 08/10/93 1230 14 150 <.5 1 <1 <3(MLS8) 08/11/93 1030 15 160 <.5 <1 <1 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
164 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/12/93 1100 16 160 <0.5 <1 <5 4 08/13/93 1150 15 150 <.5 <1 <5 <3 08/16/93 1100 18 140 <.5 1 <5 4 08/23/93 1145 18 150 <.5 1 <5 <3 08/24/93 1020 18 140 <.5 <1 <5 4 08/28/93 1120 16 150 <.5 <1 <5 4 08/29/93 1050 17 160 <.5 <1 <5 3 08/30/93 1050 5 150 <.5 2 <5 <3 2S/11W-18L14N 08/10/93 1115 14 150 <.5 <1 <5 <3 (MLS7) 08/11/93 1000 16 150 <.5 1 <5 5 08/12/93 1030 18 140 <.5 <1 <5 3 08/13/93 1040 17 130 <.5 <1 <5 5 08/16/93 1015 18 140 <.5 <1 <5 3 08/23/93 1100 17 140 <.5 <1 <5 <3 08/24/93 0930 17 130 <.5 <1 <5 5 08/28/93 1050 18 130 <.5 <1 <5 5 08/29/93 1030 19 130 <.5 <1 <5 3 08/30/93 1030 20 130 <.5 <1 <5 <3 2S/11W-18L14O 08/10/93 1010 15 150 <.5 1 <5 4 (MLS6) 08/11/93 0930 20 150 <.5 <1 <5 4 08/12/93 0930 21 140 <.5 <1 <5 5 08/13/93 1015 22 150 <.5 <1 <5 3 08/16/93 1000 21 150 <.5 <1 <5 <3 08/23/93 1050 17 150 <.5 <1 <5 4 08/24/93 0850 18 150 <.5 <1 <5 <3 08/28/93 1020 20 150 <.5 <1 <5 <3 08/29/93 1015 23 140 <.5 <1 <5 <3 08/30/93 1000 21 150 <.5 <1 <5 <3 2S/11W-18L14P 08/10/93 0846 19 140 <.5 1 <5 <3 (MLS5) 08/11/93 0900 22 140 <.5 <1 <5 4

08/12/93 0900 20 140 <.5 1 <5 4

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 165

08/13/93 0845 24 140 <0.5 <1 <5 <308/16/93 0900 22 140 <.5 <1 <5 408/23/93 0945 22 150 <.5 <1 <5 <308/24/93 0830 24 130 <.5 1 <5 408/28/93 0930 25 130 <.5 <1 <5 <308/29/93 0930 26 130 <.5 <1 <5 308/30/93 0920 29 130 <.5 1 <5 <3

2S/11W-18L14Q 08/10/93 0845 21 150 <.5 <1 <5 <3(MLS4) 08/11/93 0845 24 140 <.5 1 <5 4

08/12/93 0845 27 140 <.5 <1 <5 308/13/93 0810 27 140 <.5 2 <5 408/16/93 0845 24 140 <.5 1 <5 <308/23/93 0920 23 140 <.5 <1 <5 <308/24/93 0815 25 140 <.5 <1 <5 608/28/93 0930 24 130 <.5 1 <5 <308/29/93 0910 25 130 <.5 2 <5 408/30/93 0820 26 130 <.5 <1 <5 <3

2S/11W-18L15LYS 08/10/93 1955 2 120 <.5 <1 <1 2(SS-RED at 49 ft) 08/11/93 1815 1 120 <.5 <1 1 1

08/12/93 1550 1 120 <.5 <1 <1 108/13/93 0905 1 110 <.5 <1 <1 208/16/93 0750 1 120 <.5 <1 <1 208/23/93 0850 3 110 <.5 <1 <1 208/24/93 1800 — — — — — —08/28/93 1900 2 110 <.5 <1 <1 208/29/93 1800 3 110 .5 <1 <1 208/30/93 0900 120 <.5 <1 <1 2

2S/11W-18L16LYS 08/10/93 2015 28 45 <.5 <1 <1 2(SS-ORG at 25 ft) 08/11/93 1835 35 66 <.5 <1 1 <1

08/12/93 1555 20 100 <.5 <1 <1 <108/13/93 0915 21 110 <.5 <1 <1 <1

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
166 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 0755 17 140 <0.5 <1 <1 <1 08/23/93 0851 19 100 <10 <1 <1 <1 08/24/93 1800 23 73 <.5 <1 <5 <3 08/28/93 1900 19 120 <.5 <1 <1 1 08/29/93 1800 21 93 <.5 <1 <1 <1 08/30/93 0900 17 140 <.5 <1 <1 <1 2S/11W-18L17LYS 08/10/93 2025 10 140 <.5 <1 <1 3 (SS-YEL at 15 ft) 08/11/93 1830 7 120 <.5 <1 60 1 08/12/93 1610 7 130 <.5 <1 10 1 08/13/93 0920 8 130 <.5 <1 4 <1 08/16/93 0800 8 140 <.5 <1 2 <1 08/23/93 0853 8 130 <.5 <1 2 <1 08/24/93 1800 9 120 <.5 <1 6 <3 08/28/93 1900 9 150 <.5 <1 7 <1 08/29/93 1800 7 130 <.5 <1 <1 <1 08/30/93 0900 8 140 <.5 <1 1 <1 2S/11W-18L18LYS 08/10/93 2100

— 100 <10 <1 1

(SS-GRE at 10 ft) 08/11/93 1840

— 150 <.5 <1 1 <1

08/12/93 1615 10 150 <.5 <1 <1 <108/13/93 0925 10 150 <.5 <1 <1 <108/16/93 0805 11 160 <.5 <1 <1 <108/23/93 0854 11 140 <.5 <1 2 208/24/93 1800

—

—

—

—

—

—

08/28/93 1900 9 140 <.5 <1 2 108/29/93 1800 9 130 <.5 <1 <1 <108/30/93 0900 9 150 <.5 <1 <1 <1

2S/11W-18L19LYS 08/10/93 2110

—

—

— <1 <1 3

(SS-BLU at 5 ft) 08/11/93 1845 37 160 <.5 1 22 5

08/12/93 1620 130 <.5 <1 22 508/13/93 0930 38 63 <.5 <1 1 308/16/93 0810 33 62 <.5 <1 <1 3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 167

08/23/93 0855 34 70 <0.5 <1 5 408/24/93 1800 37 39 <.5 <1 <5 <308/28/93 1900 34 53 <.5 <1 <1 408/29/93 1800 — — — <1 <1 208/30/93 0900 32 51 <.5 <1 <1 4

2S/11W-18L20LYS 08/10/93 2107 — 100 <10 — <1 —(CR-YEL at 15 ft) 08/11/93 1855 — 140 <.5 <1 <1 <1

08/12/93 1645 10 160 .5 <1 1 <108/13/93 0940 7 150 <.5 <1 <5 <308/16/93 0925 170 <.5 <1 1 108/23/93 0902 9 150 <.5 <1 <1 308/24/93 1800 9 150 <.5 <1 <5 <308/28/93 1900 9 150 <.5 <1 <1 <108/29/93 1800 7 160 <.5 <1 <1 <108/30/93 1022 — — — <1 <1 <1

2S/11W-18L21LYS 08/10/93 2145 — — — — — —(CR-GRE at 9 ft) 08/11/93 1850 23 55 <.5 <1 <1 <1

08/12/93 1635 19 69 <.5 <1 <1 <108/13/93 0935 20 71 <.5 <1 <1 208/16/93 0920 20 74 <.5 <1 <1 208/23/93 0903 19 65 <.5 <1 <1 208/24/93 1800 22 56 <.5 <1 <5 <308/28/93 1900 19 70 <.5 <1 <1 208/29/93 1800 19 65 <.5 <1 <1 108/30/93 1020 — — — 1 <1 1

2S/11W-18L23LYS 08/10/93 2200 — — — — — —(TF-ORG at 25 ft) 08/11/93 1915 13 160 <.5 <1 <5 <3

08/16/93 1205 3 85 <.5 <1 <1 <108/23/93 0936 2 84 <.5 <1 1 <108/24/93 1800 — — — — — —08/30/93 1515 3 87 <.5 <1 <1 <1

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
168 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L25LYS 08/10/93 2205

—

—

—

—

—

—

(TF-GRE at 10 ft)2S/11W-18L26LYS 08/10/93 2110

—

—

—

—

—

—

(TF-BLU at 5 ft) 08/23/93 0940

—

—

—

—

—

—

08/24/93 1800

—

—

—

—

—

—

2S/11W-18L27 08/10/93 1835 8 86 <0.5 <1 <5 5(PR8 at 49 ft) 08/11/93 1730 8 87 <.5 <1 <5 4

08/12/93 1730 8 84 <.5 <1 <5 408/13/93 1820 7 88 <.5 <1 <5 <308/16/93 1650 7 85 <.5 <1 <5 508/23/93 1530 8 88 <.5 <1 <5 408/24/93 1305 8 85 <.5 <1 <5 408/28/93 1350 9 93 <.5 <1 <5 308/29/93 1305 8 92 <.5 <1 <5 408/30/93 1450 8 92 <.5 <1 <5 <3

2S/11W-18L28 08/10/93 2145 3 91 <.5 <1 <5 <3(PR9 at 25 ft) 08/11/93 1500 3 95 <.5 <1 <5 <3

08/12/93 1600 3 97 <.5 <1 <5 <308/13/93 1600 2 95 <.5 <1 <5 <308/16/93 1910 3 98 <.5 <1 <5 <308/23/93 1730 3 110 <.5 <1 <5 <308/24/93 1510 3 110 <.5 <1 <5 <308/28/93 1530 3 110 <.5 <1 <5 <308/29/93 1535 3 100 <.5 <1 <5 <308/30/93 1620 3 110 <.5 <1 <5 <3

2S/11W-18L29 08/10/93 1100 21 120 <.5 <1 <5 <3(PR10 at 60 ft) 08/11/93 1045 5 82 <.5 <1 <5 <3

08/12/93 0945 6 76 <.5 <1 <5 <308/13/93 1120 5 82 <.5 <1 <5 <308/16/93 1035 5 83 <.5 <1 <5 <308/23/93 1250 6 86 <.5 <1 <5 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 169

08/24/93 0720 6 85 <0.5 <1 <5 <308/28/93 1000 6 92 <.5 <1 <5 308/29/93 1140 5 94 <.5 <1 <5 <308/30/93 1250 6 94 <.5 <1 <5 <3

2S/11W-18L30 08/10/93 1550 6 79 <.5 2 <5 <3(PR11 at 36 ft) 08/11/93 1300 19 120 <.5 2 <5 <3

08/12/93 1200 22 120 <.5 <1 <5 <308/13/93 1330 20 120 <.5 <1 <5 <308/16/93 1450 19 110 <.5 <1 <5 <308/23/93 1015 19 120 <.5 <1 <5 <308/24/93 1130 18 110 <.5 <1 <5 <308/28/93 1215 18 120 <.5 <1 <5 <308/29/93 0955 18 120 <.5 1 <5 <308/30/93 1100 18 120 <.5 <1 <5 <3

POND AT PICO 08/10/93 2200 4 34 <.5 <1 <5 <3(PR12) 08/11/93 2100 3 43 <.5 <1 <5 <3

08/12/93 2030 3 38 <.5 <1 <5 <308/13/93 0910 2 44 <.5 <1 <5 <308/16/93 1940 3 38 <.5 <1 <5 <308/23/93 1920 3 42 <.5 <1 <5 <308/23/93 1930 3 42 <.5 <1 <5 <308/23/93 1950 2 41 <.5 <1 <5 <308/23/93 2030 3 39 <.5 <1 <5 <308/24/93 1720 3 41 <.5 <1 <5 <308/28/93 1745 3 40 <.5 <1 <5 <308/29/93 1700 3 38 <.5 <1 <5 <308/30/93 1745 3 39 <.5 <1 <5 <3

SEWAGE EFFLUENT 08/10/93 2245 3 42 <.5 <1 <5 <3(PR13) 08/11/93 2045 4 46 <.5 <1 <5 <3

08/12/93 1950 2 45 <.5 <1 <5 <308/13/93 1900 1 44 <.5 <1 <5 <3

Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued

Station name

(Local identifier) Date Time

Arsenic, 

dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
170 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 2000 2 41 <0.5 <1 <5 <3 08/23/93 2010 3 42 <.5 <1 <5 <3 08/24/93 1750 2 43 <.5 <1 <5 <3 08/28/93 1805 3 48 <.5 <1 <5 <3 08/29/93 1720 2 49 <.5 <1 <5 <3 08/30/93 1810 2 48 <.5 <1 <5 <3 Appendix 2C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, arsenic–cobalt—Continued Station name (Local identifier) Date Time Arsenic, dissolved 

(μg/L as As)

(01000)

Barium, 

dissolved

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt, 

dissolved 

(μg/L as Co)

(01035)
Appendixes 171

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)

2S/11W-18L10LYS 08/10/93 2110 2 53 <1 <4 910(CR-RED at 50 ft) 08/11/93 1900 2 3 1 <4 930

08/12/93 1655 2 3 1 <4 97008/13/93 1020 3 8 3 <4 97008/16/93 1050 <1 8 2 <4 99008/23/93 1054 2 <3 4 <4 96008/24/93 1800 <10 4 10 <4 86008/28/93 1900 6 9 3 <4 95008/29/93 1800 4 <3 <1 <4 1,00008/30/93 1118 4 5 1 <4 980

2S/11W-18L11LYS 08/10/93 2135 4 6 2 <4 460(CR-ORG at 25 ft) 08/11/93 1905 3 4 2 5 460

08/12/93 1700 3 5 2 9 46008/13/93 1025 5 <3 2 4 44008/16/93 1055 2 19 3 10 45008/23/93 1109 2 3 2 5 46008/24/93 1800 <10 5 <10 7 46008/28/93 1900 3 5 2 6 49008/29/93 1800 3 5 <1 4 51008/30/93 1115 3 8 2 4 470

2S/11W-18L13LYS 08/10/93 2140 9 44 <1 10 1,100(CR-BLU at 13.5 ft) 08/11/93 1910 10 21 <1 16 890

08/12/93 1710 10 14 <1 <4 76008/13/93 1030 9 16 <1 11 72008/16/93 1100 3 21 1 10 70008/23/93 1112 2 46 1 9 70008/24/93 1800 <10 39 <10 10 75008/28/93 1900 4 1,200 <1 10 990

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese[See table 1 for explanation of local identifier listed under station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, no data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; TF, Teflon lysimeter; MLS, multilevel sampler]
172 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/29/93 1800 5 27 <1 9 840 08/30/93 1120 7 — <1 —

—

2S/11W-18L14A 08/10/93 2110 <10 170 <10 6 2,400(MLS20) 08/11/93 2000 <10 140 <10 6 2,000

08/12/93 2000 <10 140 <10 11 2,00008/13/93 1920 <10 130 <10 <4 1,90008/16/93 1855 <10 150 <10 10 2,10008/23/93 1900 <10 160 <10 6 2,20008/24/93 1700 <10 110 10 7 2,10008/28/93 1730 <10 120 <10 8 1,90008/29/93 1635 <10 110 <10 <4 1,80008/30/93 1730 <10 120 <10 4 1,800

2S/11W-18L14B 08/10/93 2040 <10 24 <10 6 770(MLS19) 08/11/93 1930 <10 150 <10 5 2,100

08/12/93 1920 <10 21 <10 11 75008/13/93 1845 <10 21 <10 7 71008/16/93 1818 <10 15 <10 11 70008/23/93 1830 <10 28 <10 10 71008/24/93 1650 <10 9 <10 10 72008/28/93 1715 <10 18 <10 10 66008/29/93 1620 <10 18 20 8 69008/30/93 1715 <10 17 <10 7 660

2S/11W-18L14C 08/10/93 2005 <10 39 <10 6 760(MLS18) 08/11/93 1900 <10 31 <10 6 720

08/12/93 1845 <10 25 <10 11 67008/13/93 1800 <10 25 <10 7 63008/16/93 1745 <10 19 <10 12 63008/23/93 1815 <10 37 <10 10 68008/24/93 1615 <10 10 20 12 68008/28/93 1655 <10 26 <10 9 66008/29/93 1600 <10 23 <10 9 670

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 173

08/30/93 1630 <10 21 <10 5 660

2S/11W-18L14D 08/10/93 1930 <10 81 <10 11 920(MLS17) 08/11/93 1830 — — — — —

08/12/93 1800 <10 30 <10 12 73008/13/93 1745 <10 56 <10 8 76008/16/93 1705 <10 18 <10 8 78008/23/93 1800 <10 62 <10 13 87008/24/93 1550 <10 17 <10 11 77008/28/93 1640 <10 62 <10 10 82008/29/93 1540 <10 63 <10 7 79008/30/93 1600 <10 53 <10 7 770

2S/11W-18L14E 08/10/93 1915 <10 32 <10 10 720(MLS16) 08/11/93 1745 <10 24 10 7 660

08/12/93 1700 <10 18 <10 11 63008/13/93 1720 <10 21 10 8 60008/16/93 1620 <10 20 <10 7 66008/23/93 1710 <10 24 <10 11 78008/24/93 1525 <10 9 20 11 72008/28/93 1620 <10 22 <10 10 69008/29/93 1510 <10 23 10 6 66008/30/93 1540 <10 26 <10 7 670

2S/11W-18L14F 08/10/93 1755 <10 6 <10 6 190(MLS15) 08/11/93 1700 — — — — —

08/12/93 1620 <10 <3 <10 12 17008/13/93 1700 <10 4 10 9 17008/16/93 1530 <10 5 <10 9 23008/23/93 1700 <10 5 <10 7 28008/24/93 1450 <10 <3 <10 13 27008/28/93 1600 <10 5 10 12 26008/29/93 1450 <10 3 10 10 24008/30/93 1440 <10 6 <10 8 250

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
174 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14G 08/10/93 1710 <10 7 <10 9 240 (MLS14) 08/11/93 1610 <10 7 <10 9 250 08/12/93 1500 <10 5 <10 13 230 08/13/93 1645 <10 8 <10 11 230 08/16/93 1550 <10 7 <10 15 250 08/23/93 1630 <10 9 <10 16 310 08/24/93 1430 <10 4 10 13 290 08/28/93 1500 <10 9 <10 12 270 08/29/93 1250 <10 8 <10 12 270 08/30/93 1430 <10 7 <10 9 250 2S/11W-18L14H 08/10/93 1625 <10 8 20 9 360 (MLS13) 08/11/93 1545 <10 8 <10 10 290 08/12/93 1445 <10 5 <10 13 280 08/13/93 1620 <10 8 <10 10 290 08/16/93 1430 20 10 <10 11 320 08/23/93 1600 <10 8 <10 13 310 08/24/93 1315 <10 5 <10 15 300 08/28/93 1515 <10 9 <10 13 270 08/29/93 1235 <10 11 10 10 320 08/30/93 1310 <10 8 <10 10 310 2S/11W-18L14I 08/10/93 1525 <10 7 <10 8 180 (MLS12) 08/11/93 1520

—

—

—

—

—

08/12/93 1315 <10 4 <10 15 17008/13/93 1530 <10 8 <10 12 18008/16/93 1250 20 13 <10 12 23008/23/93 1520 <10 6 <10 14 23008/24/93 1220 <10 4 <10 13 22008/28/93 1335 <10 9 <10 13 24008/29/93 1220 <10 9 <10 9 24008/30/93 1230 <10 10 <10 11 240

2S/11W-18L14J 08/10/93 1500 <10 6 <10 9 200

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 175

(MLS11) 08/11/93 1240 <10 5 <10 11 200

08/12/93 1250 <10 <3 <10 14 18008/13/93 1500 <10 5 <10 10 17008/16/93 1245 10 6 <10 11 22008/23/93 1500 <10 4 <10 15 26008/24/93 1200 <10 3 <10 14 26008/28/93 1315 <10 6 10 13 26008/29/93 1200 <10 7 10 9 27008/30/93 1215 <10 9 10 14 280

2S/11W-18L14K 08/10/93 1415 <10 5 <10 12 290(MLS10) 08/11/93 1210 <10 7 <10 8 290

08/12/93 1220 <10 10 <10 13 27008/13/93 1300 <10 8 <10 9 24008/16/93 1200 <10 7 <10 10 29008/23/93 1230 <10 6 <10 13 40008/24/93 1105 <10 5 <10 11 40008/28/93 1250 <10 7 <10 13 40008/29/93 1125 <10 6 <10 9 41008/30/93 1150 <10 6 <10 10 380

2S/11W-18L14L 08/10/93 1345 <10 7 <10 8 290(MLS9) 08/11/93 1115 <10 5 10 10 290

08/12/93 1130 <10 <3 <10 15 27008/13/93 1230 <10 4 <10 9 23008/16/93 1130 <10 7 <10 11 30008/23/93 1210 <10 4 <10 11 42008/24/93 1045 <10 3 <10 11 40008/28/93 1230 <10 9 20 12 45008/29/93 1105 <10 5 <10 9 49008/30/93 1130 <10 <3 <10 10 470

2S/11W-18L14M 08/10/93 1230 <10 74 <10 10 1,000(MLS8) 08/11/93 1030 <10 77 <10 9 1,000

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
176 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/12/93 1100 <10 51 <10 14 960 08/13/93 1150 <10 49 <10 7 810 08/16/93 1100 <10 54 <10 13 850 08/23/93 1145 <10 66 <10 10 920 08/24/93 1020 <10 61 <10 12 850 08/28/93 1120 <10 48 <10 11 840 08/29/93 1050 <10 63 <10 8 860 08/30/93 1050 <10 59 <10 7 790 2S/11W-18L14N 08/10/93 1115 <10 11 <10 6 830 (MLS7) 08/11/93 1000 <10 15 <10 7 790 08/12/93 1030 <10 10 <10 25 720 08/13/93 1040 <10 15 <10 8 660 08/16/93 1015 <10 16 <10 8 710 08/23/93 1100 <10 14 <10 12 800 08/24/93 0930 <10 18 <10 9 720 08/28/93 1050 <10 18 <10 10 690 08/29/93 1030 <10 20 20 7 710 08/30/93 1030 <10 17 <10 5 670 2S/11W-18L14O 08/10/93 1010 <10 18 <10 10 900 (MLS6) 08/11/93 0930 <10 17 <10 9 890 08/12/93 0930 <10 17 <10 14 840 08/13/93 1015 <10 19 <10 7 840 08/16/93 1000 <10 24 <10 12 840 08/23/93 1050 <10 24 <10 11 900 08/24/93 0850 <10 16 <10 8 860 08/28/93 1020 <10 25 10 9 880 08/29/93 1015 <10 19 <10 7 840 08/30/93 1000 <10 20 <10 5 800 2S/11W-18L14P 08/10/93 0846 <10 17 <10 5 790 (MLS5) 08/11/93 0900 <10 35 <10 8 780

08/12/93 0900 <10 18 <10 13 690

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 177

08/13/93 0845 <10 19 <10 6 73008/16/93 0900 <10 20 <10 14 74008/23/93 0945 <10 47 <10 7 71008/24/93 0830 <10 18 <10 8 72008/28/93 0930 <10 23 <10 9 69008/29/93 0930 <10 21 10 6 73008/30/93 0920 <10 13 <10 5 680

2S/11W-18L14Q 08/10/93 0845 <10 6 <10 9 740(MLS4) 08/11/93 0845 <10 7 20 8 650

08/12/93 0845 <10 11 <10 11 63008/13/93 0810 <10 18 <10 7 64008/16/93 0845 <10 13 <10 12 64008/23/93 0920 <10 13 <10 12 69008/24/93 0815 <10 18 <10 10 69008/28/93 0930 <10 16 <10 10 60008/29/93 0910 <10 11 20 8 61008/30/93 0820 <10 14 <10 5 550

2S/11W-18L15LYS 08/10/93 1955 <1 70 <1 <4 430(SS-RED at 49 ft) 08/11/93 1815 <1 120 <1 <4 610

08/12/93 1550 <1 78 <1 <4 66008/13/93 0905 <1 53 <1 <4 61008/16/93 0750 <1 95 <1 <4 66008/23/93 0850 <1 21 <1 <4 58008/24/93 1800 — — — — —08/28/93 1900 <1 99 <1 <4 71008/29/93 1800 <1 94 <1 <4 66008/30/93 0900 <1 89 <1 <4 770

2S/11W-18L16LYS 08/10/93 2015 <1 43 <1 <4 10(SS-ORG at 25 ft) 08/11/93 1835 <1 13 <1 <4 44

08/12/93 1555 <1 41 <1 <4 26008/13/93 0915 <1 33 <1 <4 420

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
178 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 0755 <1 67 <1 <4 250 08/23/93 0851 <1 30 <1 <10 110 08/24/93 1800 <10 14 <10 10 40 08/28/93 1900 <1 67 <1 <4 150 08/29/93 1800 <1 20 <1 <4 170 08/30/93 0900 <1 5 <1 9 79 2S/11W-18L17LYS 08/10/93 2025 8 3,700 9 4 95 (SS-YEL at 15 ft) 08/11/93 1830 4 1,800 5 4 76 08/12/93 1610 <1 380 <1 <4 120 08/13/93 0920 <1 260 <1 7 140 08/16/93 0800 <1 150 <1 6 200 08/23/93 0853 <1 310 <1 4 87 08/24/93 1800 <10 360 <10 5 100 08/28/93 1900 <1 880 1 7 180 08/29/93 1800 <1 230 <1 5 150 08/30/93 0900 <1 230 <1 <4 220 2S/11W-18L18LYS 08/10/93 2100 3 — 2 —

—

(SS-GRE at 10 ft) 08/11/93 1840 2 6 <1 11 17

08/12/93 1615 1 6 <1 13 5808/13/93 0925 2 26 <1 18 24008/16/93 0805 <1 420 <1 15 29008/23/93 0854 3 790 4 9 16008/24/93 1800

—

—

—

—

—

08/28/93 1900 1 380 1 10 15008/29/93 1800 1 310 <1 9 15008/30/93 0900 <1 120 <1 14 210

2S/11W-18L19LYS 08/10/93 2110 1 — <1 —

—

(SS-BLU at 5 ft) 08/11/93 1845 23 13,000 47 14 250

08/12/93 1620 18 8,800 33 9 18008/13/93 0930 2 390 2 <4 3508/16/93 0810 <1 81 <1 8 33

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 179

08/23/93 0855 7 2,000 10 <4 6508/24/93 1800 <10 800 <10 <4 3408/28/93 1900 <1 280 1 <4 2208/29/93 1800 <1 — <1 — —08/30/93 0900 <1 87 <1 <4 21

2S/11W-18L20LYS 08/10/93 2107 — — — — —(CR-YEL at 15 ft) 08/11/93 1855 5 5 1 8 140

08/12/93 1645 6 14 2 7 16008/13/93 0940 <10 10 <10 10 15008/16/93 0925 4 18 2 6 17008/23/93 0902 2 15 2 10 17008/24/93 1800 <10 25 <10 11 17008/28/93 1900 7 13 1 11 18008/29/93 1800 8 15 <1 8 18008/30/93 1022 8 — 2 — —

2S/11W-18L21LYS 08/10/93 2145 — — — — —(CR-GRE at 9 ft) 08/11/93 1850 5 17 5 31 86

08/12/93 1635 4 16 3 23 13008/13/93 0935 3 10 3 21 15008/16/93 0920 4 33 4 26 16008/23/93 0903 2 27 3 25 14008/24/93 1800 <10 21 10 30 11008/28/93 1900 3 27 4 25 17008/29/93 1800 4 19 4 24 16008/30/93 1020 4 — 4 — —

2S/11W-18L23LYS 08/10/93 2200 — — — — —(TF-ORG at 25 ft) 08/11/93 1915 <10 60 10 7 860

08/16/93 1205 2 9 1 <4 13008/23/93 0936 3 <3 1 <4 13008/24/93 1800 — — — — —08/30/93 1515 3 8 <1 <4 140

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
180 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L25LYS 08/10/93 2205

—

—

—

—

—

(TF-GRE at 10 ft)2S/11W-18L26LYS 08/10/93 2110

—

—

—

—

—

(TF-BLU at 5 ft) 08/23/93 0940

—

—

—

—

—

08/24/93 1800

—

—

—

—

—

2S/11W-18L27 08/10/93 1835 <10 <3 <10 <4 520(PR8 at 49 ft) 08/11/93 1730 <10 <3 <10 <4 520

08/12/93 1730 <10 <3 <10 8 53008/13/93 1820 <10 7 <10 <4 54008/16/93 1650 <10 <3 <10 8 55008/23/93 1530 <10 <3 <10 5 56008/24/93 1305 <10 <3 <10 6 54008/28/93 1350 <10 <3 20 <4 58008/29/93 1305 <10 <3 <10 <4 58008/30/93 1450 <10 <3 <10 <4 580

2S/11W-18L28 08/10/93 2145 <10 4 <10 <4 13(PR9 at 25 ft) 08/11/93 1500 <10 <3 <10 5 13

08/12/93 1600 <10 <3 <10 9 1308/13/93 1600 <10 <3 <10 <4 1308/16/93 1910 <10 <3 <10 8 1408/23/93 1730 <10 <3 <10 6 1408/24/93 1510 <10 6 <10 7 1508/28/93 1530 <10 <3 20 7 1408/29/93 1535 <10 4 <10 4 1408/30/93 1620 <10 3 <10 5 14

2S/11W-18L29 08/10/93 1100 <10 <3 <10 9 66(PR10 at 60 ft) 08/11/93 1045 <10 <3 <10 <4 530

08/12/93 0945 <10 <3 <10 10 52008/13/93 1120 <10 <3 <10 <4 52008/16/93 1035 <10 <3 <10 10 56008/23/93 1250 <10 <3 <10 6 580

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 181

08/24/93 0720 <10 <3 <10 <4 57008/28/93 1000 <10 <3 <10 7 60008/29/93 1140 <10 <3 10 <4 61008/30/93 1250 <10 5 <10 <4 620

2S/11W-18L30 08/10/93 1550 <10 <3 <10 5 530(PR11 at 36 ft) 08/11/93 1300 <10 3 <10 9 67

08/12/93 1200 <10 <3 <10 14 6908/13/93 1330 <10 <3 <10 8 6408/16/93 1450 <10 <3 <10 13 6508/23/93 1015 <10 4 <10 14 6708/24/93 1130 <10 <3 <10 13 6308/28/93 1215 <10 4 <10 12 6108/29/93 0955 <10 6 20 10 6508/30/93 1100 <10 <3 <10 8 68

POND AT PICO 08/10/93 2200 <10 <3 <10 14 3(PR12) 08/11/93 2100 <10 15 <10 16 7

08/12/93 2030 <10 6 <10 20 408/13/93 0910 <10 9 <10 17 108/16/93 1940 <10 4 <10 21 508/23/93 1920 <10 4 <10 20 108/23/93 1930 <10 <3 <10 22 108/23/93 1950 <10 5 <10 21 308/23/93 2030 <10 4 <10 17 108/24/93 1720 <10 3 20 20 208/28/93 1745 <10 4 <10 20 408/29/93 1700 <10 <3 10 15 208/30/93 1745 <10 4 <10 17 2

SEWAGE EFFLUENT 08/10/93 2245 <10 41 <10 19 12(PR13) 08/11/93 2045 <10 31 <10 17 16

08/12/93 1950 <10 23 <10 19 1408/13/93 1900 <10 33 <10 17 14

Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper, 

dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
182 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 2000 <10 24 <10 21 15 08/23/93 2010 <10 27 <10 17 12 08/24/93 1750 <10 18 <10 19 13 08/28/93 1805 <10 27 <10 19 15 08/29/93 1720 <10 20 20 17 15 08/30/93 1810 <10 25 <10 16 15 Appendix 2D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, copper–manganese—Continued Station name (Local identifier) Date Time Copper, dissolved

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

Lithium,

dissolved 

(μg/L as Li)

(01130)

Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 183

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)

2S/11W-18L10LYS 08/10/93 2110 <10 2 <1 530 — 15(CR-RED at 50 ft) 08/11/93 1900 <10 2 <1 510 — 10

08/12/93 1655 <10 2 <1 550 — 1008/13/93 1020 <10 4 <1 530 — 5308/16/93 1050 10 2 <1 550 — 2508/23/93 1054 <10 7 <1 530 — 6808/24/93 1800 <10 <10 <1 500 9 3308/28/93 1900 20 65 <1 510 — 5708/29/93 1800 <10 9 <1 530 — 3108/30/93 1118 <10 5 <1 540 6 20

2S/11W-18L11LYS 08/10/93 2135 20 3 <1 430 — 35(CR-ORG at 25 ft) 08/11/93 1905 20 3 <1 440 — 15

08/12/93 1700 20 3 <1 460 — 1408/13/93 1025 <10 5 <1 450 — 3108/16/93 1055 30 2 <1 460 — 4008/23/93 1109 <10 6 <1 460 — 4208/24/93 1800 20 <10 <1 470 <6 2108/28/93 1900 <10 5 <1 490 — 4608/29/93 1800 <10 4 <1 490 — 3008/30/93 1115 30 3 <1 460 — 22

2S/11W-18L13LYS 08/10/93 2140 60 11 <1 590 — 21(CR-BLU at 13.5 ft) 08/11/93 1910 11 <1 560 — 8

08/12/93 1710 50 10 <1 570 — 908/13/93 1030 <10 13 <1 570 — 1408/16/93 1100 60 15 <1 560 — 1808/23/93 1112 30 14 <1 540 — 2808/24/93 1800 40 <10 <1 550 <6 1508/28/93 1900 — 12 <1 550 — 25

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, no 

data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; TF, Teflon lysimeter; MLS, multilevel sampler]
184 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/29/93 1800 50 14 <1 550

— 16

08/30/93 1120

— 11 <1 —

—

—

2S/11W-18L14A 08/10/93 2110 20 <10 3 520 <6 9(MLS20) 08/11/93 2000 10 <10 <1 480 <6 <3

08/12/93 2000 20 <10 <1 530 <6 308/13/93 1920 20 <10 <1 530 <6 <308/16/93 1855 10 <10 <1 600 <6 <308/23/93 1900 20 <10 1 630 <6 <308/24/93 1700 10 <10 1 600 <6 508/28/93 1730 <10 <10 2 560 <6 408/29/93 1635 <10 <10 <1 540 <6 <308/30/93 1730 20 <10 <1 550 <6 6

2S/11W-18L14B 08/10/93 2040 <10 <10 <1 610 <6 18(MLS19) 08/11/93 1930 20 10 <1 500 <6 <3

08/12/93 1920 20 <10 <1 670 <6 2208/13/93 1845 20 <10 <1 610 <6 2208/16/93 1818 20 <10 <1 580 <6 1808/23/93 1830 10 <10 <1 600 <6 1508/24/93 1650 20 <10 <1 630 6 2308/28/93 1715 10 <10 <1 580 <6 1408/29/93 1620 <10 <10 2 620 <6 1408/30/93 1715 <10 <10 <1 580 <6 14

2S/11W-18L14C 08/10/93 2005 <10 <10 <1 640 <6 24(MLS18) 08/11/93 1900 <10 <10 <1 630 <6 23

08/12/93 1845 10 <10 2 610 <6 2208/13/93 1800 <10 <10 <1 570 <6 2608/16/93 1745 10 <10 <1 570 <6 2208/23/93 1815 20 <10 1 610 <6 1108/24/93 1615 10 <10 1 600 8 2908/28/93 1655 <10 <10 1 570 <6 1808/29/93 1600 <10 <10 <1 590 <6 10

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 185

08/30/93 1630 10 <10 <1 580 <6 16

2S/11W-18L14D 08/10/93 1930 <10 <10 <1 630 <6 32(MLS17) 08/11/93 1830 — — — — — —

08/12/93 1800 20 <10 3 540 <6 2408/13/93 1745 <10 10 <1 560 <6 2708/16/93 1705 20 10 <1 550 <6 4708/23/93 1800 10 <10 <1 590 <6 1508/24/93 1550 10 <10 <1 600 8 3908/28/93 1640 <10 <10 <1 550 <6 1608/29/93 1540 10 <10 <1 560 <6 1508/30/93 1600 <10 <10 <1 550 <6 17

2S/11W-18L14E 08/10/93 1915 <10 <10 <1 650 <6 18(MLS16) 08/11/93 1745 <10 <10 <1 610 <6 19

08/12/93 1700 <10 <10 <1 620 <6 1908/13/93 1720 10 <10 <1 590 <6 1708/16/93 1620 10 <10 <1 610 <6 1808/23/93 1710 <10 <10 <1 690 <6 1808/24/93 1525 <10 10 <1 710 9 3508/28/93 1620 <10 <10 <1 620 <6 1408/29/93 1510 <10 <10 <1 610 <6 1008/30/93 1540 <10 <10 <1 630 <6 32

2S/11W-18L14F 08/10/93 1755 <10 <10 <1 630 6 5(MLS15) 08/11/93 1700 — — — — — —

08/12/93 1620 <10 <10 <1 700 7 708/13/93 1700 <10 <10 <1 650 7 908/16/93 1530 <10 <10 <1 770 <6 808/23/93 1700 <10 <10 <1 770 <6 1008/24/93 1450 <10 <10 <1 780 8 1008/28/93 1600 <10 <10 <1 730 <6 608/29/93 1450 <10 <10 <1 750 <6 508/30/93 1440 <10 <10 <1 720 <6 9

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
186 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14G 08/10/93 1710 <10 <10 <1 610 <6 11 (MLS14) 08/11/93 1610 <10 <10 <1 630 <6 17 08/12/93 1500 <10 <10 <1 630 <6 14 08/13/93 1645 10 <10 <1 650 <6 13 08/16/93 1550 <10 <10 <1 710 <6 14 08/23/93 1630 10 <10 2 700 9 15 08/24/93 1430 <10 <10 <1 790 7 11 08/28/93 1500 <10 <10 <1 670 6 21 08/29/93 1250 20 <10 <1 690 <6 16 08/30/93 1430 <10 <10 <1 670 <6 7 2S/11W-18L14H 08/10/93 1625 <10 <10 <1 610 <6 6 (MLS13) 08/11/93 1545 <10 <10 <1 640 <6 6 08/12/93 1445 <10 <10 1 670 <6 7 08/13/93 1620 <10 <10 <1 660 <6 17 08/16/93 1430 10 <10 <1 620 <6 13 08/23/93 1600 <10 <10 <1 650 7 5 08/24/93 1315 <10 <10 <1 650 <6 13 08/28/93 1515 <10 <10 2 610 7 3 08/29/93 1235 <10 <10 <1 640 <6 4 08/30/93 1310 <10 <10 <1 620 <6 7 2S/11W-18L14I 08/10/93 1525 <10 <10 <1 590 <6 5 (MLS12) 08/11/93 1520

—

—

—

—

—

—

08/12/93 1315 <10 <10 2 640 <6 708/13/93 1530 <10 <10 <1 650 6 1208/16/93 1250 20 10 <1 550 <6 1508/23/93 1520 10 <10 <1 640 7 608/24/93 1220 10 <10 <1 630 <6 2308/28/93 1335 <10 <10 1 610 <6 708/29/93 1220 <10 <10 <1 610 <6 508/30/93 1230 <10 <10 <1 620 <6 5

2S/11W-18L14J 08/10/93 1500 <10 <10 <1 600 <6 4

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 187

(MLS11) 08/11/93 1240 <10 <10 <1 610 <6 <3

08/12/93 1250 <10 <10 2 630 <6 508/13/93 1500 20 <10 <1 560 <6 808/16/93 1245 30 10 <1 500 7 908/23/93 1500 <10 <10 3 590 9 <308/24/93 1200 <10 <10 <1 600 <6 608/28/93 1315 <10 <10 2 590 7 308/29/93 1200 <10 <10 <1 610 <6 <308/30/93 1215 <10 <10 2 650 6 <3

2S/11W-18L14K 08/10/93 1415 <10 <10 <1 620 <6 7(MLS10) 08/11/93 1210 <10 <10 <1 610 <6 10

08/12/93 1220 10 <10 1 630 7 908/13/93 1300 20 <10 <1 510 <6 1308/16/93 1200 30 10 <1 490 6 1608/23/93 1230 10 <10 <1 550 7 908/24/93 1105 <10 <10 <1 570 <6 1108/28/93 1250 <10 <10 <1 600 <6 808/29/93 1125 <10 <10 <1 610 <6 908/30/93 1150 10 <10 <1 600 <6 4

2S/11W-18L14L 08/10/93 1345 <10 <10 <1 600 <6 6(MLS9) 08/11/93 1115 10 <10 1 610 <6 7

08/12/93 1130 10 <10 1 610 <6 808/13/93 1230 20 <10 <1 500 6 1108/16/93 1130 20 10 <1 470 6 2508/23/93 1210 20 <10 1 540 7 408/24/93 1045 10 <10 <1 510 7 808/28/93 1230 <10 <10 <1 600 7 908/29/93 1105 <10 10 <1 610 6 608/30/93 1130 <10 <10 <1 620 <6 <3

2S/11W-18L14M 08/10/93 1230 10 <10 1 550 <6 19(MLS8) 08/11/93 1030 <10 10 <1 540 <6 25

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
188 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/12/93 1100 20 <10 2 560 <6 20 08/13/93 1150 <10 <10 <1 510 <6 22 08/16/93 1100 20 10 <1 510 <6 35 08/23/93 1145 20 <10 <1 550 <6 13 08/24/93 1020 20 <10 <1 510 <6 18 08/28/93 1120 <10 <10 <1 520 <6 18 08/29/93 1050 <10 <10 1 560 <6 15 08/30/93 1050 10 <10 <1 550 <6 13 2S/11W-18L14N 08/10/93 1115 20 <10 <1 480 <6 9 (MLS7) 08/11/93 1000 30 10 <1 460 <6 6 08/12/93 1030 20 10 <1 450 <6 5 08/13/93 1040 20 <10 <1 430 <6 3 08/16/93 1015 30 10 <1 440 <6 10 08/23/93 1100 20 <10 <1 460 <6 8 08/24/93 0930 20 <10 <1 440 <6 10 08/28/93 1050 <10 <10 2 420 <6 5 08/29/93 1030 <10 <10 <1 440 <6 10 08/30/93 1030 <10 <10 <1 430 <6 4 2S/11W-18L14O 08/10/93 1010 20 10 <1 500 <6 8 (MLS6) 08/11/93 0930 20 <10 <1 450 <6 11 08/12/93 0930 20 <10 2 440 <6 11 08/13/93 1015 20 <10 <1 460 <6 12 08/16/93 1000 20 10 <1 460 <6 18 08/23/93 1050 20 <10 <1 500 <6 9 08/24/93 0850 10 <10 <1 460 <6 10 08/28/93 1020 <10 <10 <1 490 <6 10 08/29/93 1015 <10 <10 <1 450 <6 8 08/30/93 1000 20 <10 <1 460 <6 8 2S/11W-18L14P 08/10/93 0846 20 10 <1 510 <6 8 (MLS5) 08/11/93 0900 20 10 <1 470 <6 13

08/12/93 0900 10 <10 <1 460 <6 14

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 189

08/13/93 0845 <10 10 <1 450 <6 2108/16/93 0900 30 20 <1 480 <6 1508/23/93 0945 20 10 <1 510 <6 1108/24/93 0830 10 <10 <1 450 <6 1008/28/93 0930 <10 <10 <1 440 <6 1008/29/93 0930 <10 <10 <1 430 <6 1008/30/93 0920 <10 <10 <1 440 <6 8

2S/11W-18L14Q 08/10/93 0845 20 10 <1 460 <6 12(MLS4) 08/11/93 0845 <10 20 <1 420 <6 6

08/12/93 0845 20 <10 <1 440 <6 808/13/93 0810 20 <10 <1 410 <6 908/16/93 0845 20 20 <1 430 <6 1208/23/93 0920 20 <10 <1 440 <6 408/24/93 0815 20 10 1 460 <6 1108/28/93 0930 10 <10 <1 420 <6 808/29/93 0910 <10 10 <1 430 <6 1108/30/93 0820 <10 <10 <1 430 <6 7

2S/11W-18L15LYS 08/10/93 1955 <10 8 <1 530 — <3(SS-RED at 49 ft) 08/11/93 1815 <10 8 <1 500 — 9

08/12/93 1550 20 6 <1 470 — 408/13/93 0905 <10 5 <1 450 — 508/16/93 0750 <10 7 <1 450 — 308/23/93 0850 <10 11 <1 480 — <308/24/93 1800 — — — — — —08/28/93 1900 20 6 <1 470 — 708/29/93 1800 <10 5 <1 510 — 308/30/93 0900 10 7 <1 520 — 6

2S/11W-18L16LYS 08/10/93 2015 20 8 <1 310 — <3(SS-ORG at 25 ft) 08/11/93 1835 10 5 <1 380 — 8

08/12/93 1555 <10 3 <1 560 — <308/13/93 0915 <10 4 <1 600 — 6

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
190 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 0755 10 5 <1 710

— <3

08/23/93 0851 16 12 <1 550 <1 <1008/24/93 1800 20 <10 <1 420 <6 408/28/93 1900 20 6 <1 590

— 7

08/29/93 1800 <10 10 <1 470

— <3

08/30/93 0900 20 10 <1 630 <1 4

2S/11W-18L17LYS 08/10/93 2025 30 110 3 510

— 32

(SS-YEL at 15 ft) 08/11/93 1830 <10 62 4 520 1 24

08/12/93 1610 <10 11 <1 600

— 5

08/13/93 0920 <10 10 <1 610

— <3

08/16/93 0800 <10 11 <1 670

— <3

08/23/93 0853 10 13 <1 640

— <3

08/24/93 1800 <10 <10 1 590 <6 708/28/93 1900 20 16 <1 710

— 7

08/29/93 1800 <10 18 <1 640

— <3

08/30/93 0900 20 21 <1 700

— <3

2S/11W-18L18LYS 08/10/93 2100

— 5 <1 —

—

—

(SS-GRE at 10 ft) 08/11/93 1840 <10 4 <1 630

— 5

08/12/93 1615 <10 3 <1 600

— <3

08/13/93 0925 20 4 <1 600

— 9

08/16/93 0805 20 4 <1 620

— 6

08/23/93 0854 <10 9 <1 550

— 8

08/24/93 1800

—

—

—

—

—

—

08/28/93 1900 <10 7 <1 550

— 8

08/29/93 1800 20 5 <1 540

— 8

08/30/93 0900 10 4 <1 600

— <3

2S/11W-18L19LYS 08/10/93 2110

— 15 <1 —

—

—

(SS-BLU at 5 ft) 08/11/93 1845 10 82 2 370

— 110

08/12/93 1620 40 60 3 400

— 69

08/13/93 0930 20 14 <1 360

— 7

08/16/93 0810 70 10 <1 390

— 11

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 191

08/23/93 0855 40 27 <1 300 — 2608/24/93 1800 30 10 <1 250 <6 808/28/93 1900 40 11 <1 340 — 708/29/93 1800 — 12 <1 — — —08/30/93 0900 30 9 <1 320 — 4

2S/11W-18L20LYS 08/10/93 2107 — — — — — —(CR-YEL at 15 ft) 08/11/93 1855 <10 3 <1 540 — 52

08/12/93 1645 10 4 <1 610 — 5508/13/93 0940 30 <10 <1 570 <6 5708/16/93 0925 <10 5 <1 630 — 12008/23/93 0902 10 9 <1 550 — 5008/24/93 1800 10 20 <1 580 <6 5608/28/93 1900 20 9 <1 590 — 5908/29/93 1800 <10 7 <1 620 — 5108/30/93 1022 — 6 <1 — — —

2S/11W-18L21LYS 08/10/93 2145 — — — — — —(CR-GRE at 9 ft) 08/11/93 1850 <10 10 <1 310 — 29

08/12/93 1635 <10 9 <1 380 — 2508/13/93 0935 <10 9 <1 380 — 708/16/93 0920 <10 16 <1 380 — 3808/23/93 0903 10 15 <1 340 — 3408/24/93 1800 30 10 <1 300 <6 2008/28/93 1900 <10 12 <1 370 — 3508/29/93 1800 30 13 <1 350 — 2108/30/93 1020 — 13 <1 — — —

2S/11W-18L23LYS 08/10/93 2200 — — — — — —(TF-ORG at 25 ft) 08/11/93 1915 10 <10 <1 590 <6 28

08/16/93 1205 <10 2 <1 560 — 1008/23/93 0936 <10 2 <1 550 — <308/24/93 1800 — — — — — —08/30/93 1515 10 2 <1 570 — <3

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
192 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L25LYS 08/10/93 2205

—

—

—

—

—

—

(TF-GRE at 10 ft)2S/11W-18L26LYS 08/10/93 2110

—

—

—

—

—

—

(TF-BLU at 5 ft) 08/23/93 0940

—

—

—

—

—

—

08/24/93 1800

—

—

—

—

—

—

2S/11W-18L27 08/10/93 1835 20 <10 <1 500 <6 <3(PR8 at 49 ft) 08/11/93 1730 <10 <10 <1 490 <6 <3

08/12/93 1730 10 <10 2 480 <6 <308/13/93 1820 <10 <10 <1 490 <6 <308/16/93 1650 10 <10 <1 490 <6 <308/23/93 1530 10 <10 <1 510 <6 <308/24/93 1305 <10 <10 <1 490 <6 <308/28/93 1350 <10 <10 1 520 <6 <308/29/93 1305 <10 <10 <1 510 <6 508/30/93 1450 <10 <10 <1 510 <6 7

2S/11W-18L28 08/10/93 2145 <10 <10 <1 530 <6 <3(PR9 at 25 ft) 08/11/93 1500 <10 <10 <1 560 <6 <3

08/12/93 1600 <10 <10 1 580 <6 408/13/93 1600 <10 <10 <1 560 <6 408/16/93 1910 <10 <10 <1 600 <6 <308/23/93 1730 <10 <10 <1 660 <6 <308/24/93 1510 10 <10 <1 640 <6 <308/28/93 1530 <10 <10 <1 660 <6 <308/29/93 1535 <10 <10 <1 610 <6 <308/30/93 1620 <10 <10 <1 620 <6 4

2S/11W-18L29 08/10/93 1100 <10 <10 <1 540 7 8(PR10 at 60 ft) 08/11/93 1045 20 <10 <1 460 <6 <3

08/12/93 0945 20 <10 2 440 <6 <308/13/93 1120 <10 <10 <1 450 <6 308/16/93 1035 20 <10 <1 470 <6 408/23/93 1250 20 <10 2 490 <6 <3

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 193

08/24/93 0720 10 <10 <1 480 <6 408/28/93 1000 <10 <10 <1 500 <6 <308/29/93 1140 10 <10 <1 520 <6 408/30/93 1250 10 <10 <1 510 <6 5

2S/11W-18L30 08/10/93 1550 20 <10 <1 460 <6 <3(PR11 at 36 ft) 08/11/93 1300 <10 <10 <1 540 7 <3

08/12/93 1200 10 <10 <1 560 6 <308/13/93 1330 <10 <10 <1 510 7 408/16/93 1450 <10 <10 <1 510 7 <308/23/93 1015 <10 <10 1 520 8 <308/24/93 1130 <10 <10 <1 500 7 <308/28/93 1215 <10 <10 <1 500 7 <308/29/93 0955 <10 <10 <1 540 7 408/30/93 1100 <10 <10 <1 540 <6 <3

POND AT PICO 08/10/93 2200 10 <10 <1 510 <6 10(PR12) 08/11/93 2100 20 10 <1 540 <6 35

08/12/93 2030 20 <10 2 510 <6 2908/13/93 0910 10 10 <1 530 <6 3608/16/93 1940 20 <10 <1 520 <6 2808/23/93 1920 20 <10 <1 540 <6 4608/23/93 1930 10 <10 <1 540 <6 5008/23/93 1950 10 <10 <1 530 <6 4408/23/93 2030 20 10 <1 550 <6 3608/24/93 1720 20 <10 <1 540 <6 3808/28/93 1745 <10 <10 <1 520 <6 3208/29/93 1700 10 <10 <1 510 <6 3108/30/93 1745 20 <10 <1 520 <6 48

SEWAGE EFFLUENT 08/10/93 2245 30 <10 <1 540 <6 60(PR13) 08/11/93 2045 <10 <10 <1 540 <6 58

08/12/93 1950 10 10 <1 530 <6 4908/13/93 1900 <10 <10 <1 510 <6 42

Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
194 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 08/16/93 2000 10 10 <1 510 <6 45 08/23/93 2010 20 <10 2 530 <6 51 08/24/93 1750 20 <10 <1 520 <6 55 08/28/93 1805 20 <10 <1 510 <6 51 08/29/93 1720 10 10 <1 540 <6 55 08/30/93 1810 10 <10 <1 520 <6 52 Appendix 2E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during August 1993, molybdenum–zinc—Continued Station name (Local identifier) Date Time Molybdenum, dissolved

(μg/L as Mo)

(01060)

Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

 Strontium, 

dissolved 

(μg/L as Sr)

(01080)

Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 195

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)

2S/11W-18L14A 04/04/94 1940 — 7.1 936 — 260 73 19 84 160(MLS20) 04/05/94 1205 — 7 927 21.8 270 77 19 81 160

04/05/94 1800 2 7 925 21.7 270 76 19 81 16004/06/94 1400 2.4 7.1 923 21.9 260 72 19 82 16004/07/94 0900 2.2 7 1,020 22 290 81 20 88 16004/08/94 0825 2.2 7 1,050 21.8 280 79 21 100 17004/21/94 0915 — 7.1 1,060 23 230 64 17 120 18006/01/94 1455 .4 7.1 1,000 23 230 64 16 110 170

2S/11W-18L14C 04/07/94 0915 3.8 7.1 1,090 22.3 250 72 18 110 180(MLS18) 04/08/94 0830 2.8 7.1 1,130 22.3 260 73 19 130 1802S/11W-18L14F 04/04/94 1930 — 7 958 — 280 76 21 83 160(MLS15) 04/05/94 1145 1.8 6.9 940 21.9 280 79 20 81 160

04/05/94 1750 2.2 7 925 21.8 270 76 20 81 16004/06/94 1350 5.8 7.1 1,080 21.3 270 73 20 110 17004/07/94 0945 2.8 7 1,100 22.6 250 71 18 120 18004/08/94 0845 4.8 7 1,200 22.1 310 85 23 130 17004/21/94 0945 — 7.1 1,040 23 210 59 16 120 17006/01/94 1435 .6 7.1 1,050 22 240 67 17 120 180

2S/11W-18L14K 04/04/94 1855 .6 7.2 919 — 230 64 17 91 170(MLS10) 04/05/94 1123 1.8 7.1 924 21.4 250 70 18 91 170

04/05/94 1740 2.2 7.2 926 21.2 250 71 18 90 18004/06/94 1145 5.2 7.1 1,100 20.3 270 75 20 120 18004/07/94 1000 6.6 7.1 1,130 22.7 250 73 17 120 18004/08/94 0910 4.6 7.1 1,120 22.7 250 71 17 120 18004/21/94 1000 — 7.1 1,040 23 220 61 16 120 180

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; μS/cm, microsiemens per centimeter; oC, degrees Celsius; ft, feet below basin floor or land surface; 

mg/L, milligrams per liter; —, no data; MLS, multilevel sampler]
196 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 06/01/94 1350 .4 7.2 1,030 20.5 290 78 22 94 180 2S/11W-18L14L 04/04/94 1835 0.8 7.2 920

— 240 66 17 90 170

(MLS9) 04/05/94 1100 .6 7 929 21.2 260 73 18 90 180

04/05/94 1645 3 7.1 920 20.9 250 72 18 88 17004/06/94 1125 6 7.1 1,100 20.2 280 77 20 110 17004/07/94 1018 4.6 7 1,120 23 240 69 17 120 18004/08/94 0945 1.8 7.1 1,110 22.9 250 71 17 120 18004/21/94 1020

— 7.1 1,030 23 220 59 17 120 170

06/01/94 1315 .6 7 1,030 20 290 78 23 91 180

2S/11W-18L14M 04/04/94 1750 1.2 7 942

— 250 71 18 88 160

(MLS8) 04/05/94 1046 2 7 947 21.3 270 75 19 91 160

04/05/94 1635 3 7 943 21.3 270 75 19 90 16004/06/94 1045 4.6 7.1 1,060 20.7 280 78 20 100 17004/07/94 1040 4.2 7.1 1,120 23 250 71 18 120 18004/08/94 0930 4.6 7.1 1,200 22.4 290 83 21 130 18004/21/94 1040

— 7.2 1,050 23 230 62 17 120 180

06/01/94 1210 .4 7.2 1,040 21 260 71 19 110 190

2S/11W-18L14N 04/04/94 1730 1 7.1 937

— 250 70 19 90 160

(MLS7) 04/05/94 1010 1 7 925 20.6 250 71 18 87 170

04/05/94 1540 2.8 7.1 928 20.8 250 71 18 89 17004/06/94 1000 2.8 7.1 1,070 21 280 78 20 100 17004/07/94 1100 4.8 7 1,120 23 250 69 18 120 18004/08/94 0950 2.6 7.1 1,150 22.7 270 76 19 130 18004/21/94 1050

— 7.2 1,050 23 210 58 16 120 180

06/01/94 1100 .6 7.2 1,040 20.5 250 67 19 110 190

2S/11W-18L14O 04/04/94 1715 1.8 7.1 907

— 240 67 18 88 160

(MLS6) 04/05/94 0950 1.2 7 929 20.7 260 72 19 88 160

04/05/94 1532 2.2 7.1 945 20.6 270 75 19 89 160

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(

oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)
Appendixes 197

04/06/94 0950 3.8 7.1 1,090 21.2 270 75 20 110 17004/07/94 1120 4.8 7.1 1,120 22.9 250 71 17 120 18004/08/94 1045 3.2 7.1 1,150 22.7 270 75 19 130 18004/21/94 1105 — 7.1 1,050 23 220 60 17 120 18006/01/94 1040 .4 7.2 1,060 21 230 64 18 110 210

2S/11W-18L14P 04/04/94 1630 1.2 7.2 936 — 250 69 18 86 160(MLS5) 04/05/94 0900 2.8 7 933 20.8 250 72 18 87 160

04/05/94 1505 3.2 7 979 20.8 280 77 20 91 16004/06/94 0818 4.6 7.1 1,080 21 270 73 20 110 17004/07/94 1130 3.2 7.1 1,130 22.9 240 68 17 130 18004/08/94 1055 3 7.1 1,170 22.4 270 74 20 130 18004/21/94 1135 — 7.2 1,050 23 220 61 17 120 18006/01/94 0935 .6 7.2 1,050 21 250 68 20 110 200

2S/11W-18L14Q 04/04/94 1605 — 7.1 1,040 — 260 69 20 110 140(MLS4) 04/05/94 0830 6.4 7 1,120 19.5 280 77 21 120 140

04/05/94 1450 6.4 7 1,210 19.7 350 95 26 120 14004/06/94 0820 5 7.1 1,130 21.9 220 59 17 140 18004/07/94 1144 2.8 7.2 1,150 23 210 58 16 150 19004/08/94 1125 2 7.1 1,150 22.7 270 75 19 130 18004/21/94 1145 — 7.5 1,070 23 200 53 16 140 18006/01/94 0915 .8 7.3 1,090 22 220 59 18 140 240

2S/11W-18L27 04/04/94 1905 — 7.1 910 — 290 81 21 74 160(PR8 at 49 ft) 04/05/94 1700 — 7.1 897 — 290 80 21 73 160

04/06/94 1030 1.6 7.1 911 20.6 280 78 20 71 16004/07/94 1425 — 7.2 910 — 270 76 20 71 16004/08/94 1040 4 7.1 923 20.2 290 81 21 74 16004/21/94 1740 — 7.1 927 20.4 300 83 22 75 16006/01/94 1330 — 7 920 22 280 78 20 78 160

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)
198 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L28 04/04/94 1720 1.6 7 933

— 290 80 21 72 150

(PR9 at 25 ft) 04/05/94 1805 2.4 6.9 928

— 280 80 20 75 150

04/06/94 1205 2.8 6.9 958 22.8 280 77 21 79 16004/07/94 1200

— 6.9 1,030 22.7 290 82 21 88 160

04/08/94 1000 1.4 6.9 1,060 21.9 300 82 22 100 16004/21/94 1625

— 7 1,060

— 220 61 17 120 170

06/01/94 1515 .6 6.9 1,050 24 260 71 19 110

—

2S/11W-18L29 04/04/94 2000

— 7.1 957

— 320 88 23 69 170

(PR10 at 50 ft) 04/05/94 1405

— 7.1 952

— 320 88 23 71 170

04/06/94 1550

— 7.2 952 20.7 300 83 22 72 170

04/07/94 1030

— 7.1 951 19.7 300 84 21 69 170

04/07/94 1200

— 7.1 951 19.7

—

—

—

— 170

04/08/94 1200 3.4 7.1 956

— 310 85 23 72 170

04/21/94 1445

— 7 933 21 310 85 23 70 160

06/01/94 1130

— 7 937 21 300 83 22 73 160

2S/11W-18L30 04/04/94 1550

— 7 914 22.8 250 71 18 85 160

(PR11 at 36 ft) 04/05/94 1550 2 7 911

— 250 70 18 84 160

04/06/94 1445

— 6.9 922 22.4 250 70 18 85 160

04/07/94 0930 1.6 6.9 947 22 260 76 18 83 15004/07/94 0931 6.9 945 22 270 78 19 87 15004/08/94 1200 1.6 6.8 1,040 22 300 87 21 91 16004/21/94 1315

— 7 1,050 22.5 230 65 17 120 170

06/01/94 1015

— 6.8 984

— 240 69 17 100 160

POND AT PICO 04/05/94 0845

— 7.3 1,100 22.8 230 62 19 120 190

(PR12) 04/05/94 0943

— 7.3 1,100 21.5 230 61 18 120 190

04/05/94 1055

— 7.3 1,110

— 240 63 19 120 190

04/05/94 1154

— 7.3 1,100

— 240 63 19 120 190

04/05/94 1421

— 7.3 1,080

— 230 61 19 120 180

04/05/94 1607

— 7.3 1,100

— 230 62 19 120 190

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(

oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)
Appendixes 199

04/05/94 1714 — 7.4 1,120 — 240 63 19 120 19004/05/94 1830 — 7.3 1,130 24.2 240 64 19 120 18004/06/94 0745 — 7.3 1,130 — 230 60 19 130 19004/07/94 0800 4.6 7.2 1,150 22.3 230 61 18 130 19004/07/94 0805 5.6 7.2 1,150 22.3 240 63 19 130 19004/07/94 0810 5.4 7.2 1,150 22.1 220 60 18 130 19004/07/94 1430 4.8 7.3 1,130 23.1 230 61 18 120 19004/07/94 1530 4.6 7.3 1,120 23.4 230 61 18 120 18004/07/94 1540 5 7.3 1,130 23 230 61 18 120 19004/07/94 1825 5 7.3 1,130 23.1 230 63 18 120 19004/07/94 1830 5 7.3 1,130 22.9 230 61 18 120 19004/07/94 1845 4.6 7.2 1,130 22.9 220 59 18 120 19004/08/94 1130 — 7.2 1,140 22.4 240 63 19 130 19004/21/94 0800 — 7.3 1,180 21.9 230 60 19 120 18004/21/94 0815 — 7.2 1,070 23 230 60 19 120 17004/21/94 0820 — 7.2 1,070 21.4 220 57 18 120 17004/21/94 0825 — 7.2 1,070 21.4 230 61 18 120 180

SEWAGE EFFLUENT 04/05/94 0915 — 7.3 1,090 — 220 60 18 120 —(PR13) 04/05/94 1020 — 7.3 1,100 — 230 61 19 120 190

04/05/94 1105 — 7.3 1,060 — 230 61 18 120 18004/05/94 1210 — 7.3 1,060 — 230 60 19 120 18004/05/94 1420 — 7.3 1,110 — 240 64 19 120 18004/05/94 1545 — 7.3 1,150 — 240 63 19 120 19004/05/94 1650 — 7.5 1,160 — 240 64 19 120 19004/05/94 1835 — 7.2 1,160 21.7 230 62 19 120 19004/06/94 1215 — 7.5 1,080 23.3 230 61 18 130 19004/07/94 1215 6.8 7.3 1,060 23.4 220 59 18 120 18004/08/94 1215 7 7.3 1,100 23.3 230 59 19 130 210

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)
200 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/21/94 1530

— 7.3 1,110 24 220 59 18 120 190

Appendix 3A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, oxygen–alkalinity—Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

pH, 

field, 

(standard 

units)

(00400)

Specific 

conductance, 

field

(μS/cm)

(00095)

Water 

temperature 

(

oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L 

as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L 

as Mg)(00925)

Sodium, 

dissolved 

(mg/L 

as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field, 

(mg/L as 

CaCO3)

(39036)
200 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus—Continued Station name (Local Identifier) Date Time Bromide, dissolved (mg/L as Br) (71870) Chloride, dissolved (mg/L as Cl) (00940) Fluoride, dissolved (mg/L as F) (00950) Silica, dissolved (mg/L as SiO2) (00955) Sulfate, dissolved (mg/L as SO4) (00945) Nitrogen, ammonia, dissolved (mg/L as N) (00608) Nitrogen, nitrate, dissolved (mg/L as N) (00618) Nitrogen, nitrite plus nitrate, dissolved (mg/L as N) (00631) Nitrogen, nitrite, dissolved, mg/L as N (00613) Phos- phorus, ortho phosphate, dissolved (mg/L as P) (00671) 2S/11W-18L14A 04/04/94 1940

— 102

— 24 158 0.23 0.87 0.89 0.02 0.3

(MLS20) 04/05/94 1205

— 104

— 25 162 .21 .97 .99 .02 .24

04/05/94 1800

— 101

— 25 158 .2 .95 .97 .02 .25

04/06/94 1400

—

—

— 23

— .14 2.07 2.1 .03 .21

04/07/94 0900

— 119

— 24 157 .16 4.75 5.3 .55 .24

04/08/94 0825

— 127

— 23 154 .16 5.75 6.3 .55 .23

04/21/94 0915

— 129

— 21 147 .19 3.2 4.4 1.2 .31

06/01/94 1455

— 108

— 22 152 .15 1.36 1.4 .04 .32

2S/11W-18L14C 04/07/94 0915

— 129

— 22 147 .1 7.17 7.8 .63 .71

(MLS18) 04/08/94 0830

— 133

— 22 163 .33 7.15 7.8 .65 .88

2S/11W-18L14F 04/04/94 1930

— 112

— 22 162 .02 1.26 1.3 .04 .29

(MLS15) 04/05/94 1145

— 118

— 23 172 .03 1.36 1.4 .04 .28

04/05/94 1750

— 104

— 21 160 .02 1.68 1.7 .02 .29

04/06/94 1350

— 135

— 20 154 .02 7.2 8.3 1.1 .35

04/07/94 0945

— 133

— 21 150 .03 7.1 8.2 1.1 .55

04/08/94 0845

— 133

— 22 208 .05 9.63 9.7 .07 .64

04/21/94 0945

— 129

— 20 144 1.9 2.27 2.3 .03 .98

06/01/94 1435

— 121

— 20 143 1.3 3.28 3.3 .02 .79

2S/11W-18L14K 04/04/94 1855

— 93

— 19 154 .02 2.38 2.4 .02 .61

(MLS10) 04/05/94 1123

— 92

— 19 154 .04 2.47 2.5 .03 .59

04/05/94 1740

— 90

— 19 155

—

—

—

—

—

04/06/94 1145

— 132

— 21 155 .02 8.95 9.1 .15 .75

04/07/94 1000

— 136

— 21 153 .04 7.86 8.2 .34 1

04/08/94 0910

— 136

— 20 149 .04 7.22 7.9 .68 1.1

04/21/94 1000

— 128

— 20 144 1.5 2.69 2.7 .01 1.3

Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less than value shown; —, no data; MLS, multilevel sampler]
Appendixes 201

06/01/94 1350 — 112 — 16 162 1.2 .66 .68 .02 .93

2S/11W-18L14L 04/04/94 1835 — 91 — 18 152 0.04 2.47 2.5 0.03 0.5(MLS9) 04/05/94 1100 — 91 — 19 153 .02 2.58 2.6 .02 .56

04/05/94 1645 — 88 — 19 155 .02 3.09 3.1 .01 .4904/06/94 1125 — 131 — 21 158 .02 8.53 8.8 .27 .8604/07/94 1018 — 138 — 20 151 .03 7.4 8.2 .8 .9204/08/94 0945 — 136 — 20 146 .19 6.1 7.6 1.5 1.104/21/94 1020 — 127 — 19 141 1.5 3.69 3.7 .01 1.506/01/94 1315 — 112 — 16 167 1.4 .58 .59 .01 .98

2S/11W-18L14M 04/04/94 1750 — 99 — 22 162 .12 1.66 1.7 .04 .6(MLS8) 04/05/94 1046 — 96 — 22 169 .1 2.15 2.2 .05 .63

04/05/94 1635 — 94 — 21 168 .08 2.46 2.5 .04 .5904/06/94 1045 — 124 — 21 158 .09 6.47 6.9 .43 .5704/07/94 1040 — 134 — 21 156 .12 7.34 7.8 .46 .9704/08/94 0930 — 135 — 22 199 .18 8.3 8.7 .4 .9704/21/94 1040 — 128 — 21 146 1.6 2.05 2.1 .05 1.206/01/94 1210 — 116 — 19 149 1.2 1.07 1.1 .03 1

2S/11W-18L14N 04/04/94 1730 — 86 — 21 181 .1 2.8 2.9 .1 .83(MLS7) 04/05/94 1010 — 91 — 20 163 .06 2.77 2.8 .03 .76

04/05/94 1540 — 91 — 20 162 .05 2.77 2.8 .03 .7104/06/94 1000 — 121 — 21 168 .05 7.21 7.7 .49 .804/07/94 1100 — 134 — 21 151 .05 7.55 8.1 .55 .9904/08/94 0950 — 135 — 21 172 .2 7.84 8.4 .56 1.104/21/94 1050 — 128 — 19 143 1.5 2.72 3 .28 1.306/01/94 1100 — 115 — 20 148 1.2 .53 .55 .02 1.3

2S/11W-18L14O 04/04/94 1715 — 86 — 20 165 .03 2.97 3 .03 .84(MLS6) 04/05/94 0950 — 92 — 20 166 .06 2.56 2.6 .04 .8

04/05/94 1532 — 90 — 20 177 .03 3.28 3.3 .02 .71

Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus—Continued

Station name

(Local Identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L 

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

mg/L as N

(00613)

Phosphorus, 

ortho

phosphate, 

dissolved 

(mg/L as P)

(00671)
202 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/06/94 0950

— 126

— 21 162

—

—

—

—

—

04/07/94 1120

— 136

— 21 153 0.08 7.81 8.4 0.59 1.1

04/08/94 1045

— 136

— 21 169 .34 7.41 8.2 .79 1.2

04/21/94 1105

— 130

— 20 146 1.8 2.27 2.4 .13 1.3

06/01/94 1040

— 120

— 20 139 1.4 .89 .92 .03 1.4

2S/11W-18L14P 04/04/94 1630

— 95

— 20 167 .04 2.05 2.1 .05 .65

(MLS5) 04/05/94 0900

— 96

— 21 162 .04 2.16 2.2 .04 .63

04/05/94 1505

— 90

— 21 191 .04 3.38 3.4 .02 .68

04/06/94 0818

— 119

— 21 175 .03 7.51 7.9 .39 .89

04/07/94 1130

— 141

— 21 160 .25 7.25 8.1 .85 1.1

04/08/94 1055

— 136

— 22 178 .95 7.57 8.4 .83 1.1

04/21/94 1135

— 128

— 20 146 1.8 2.18 2.3 .12 1.2

06/01/94 0935

— 121

— 19 137 1.3 .77 0.8 .03 1.3

2S/11W-18L14Q 04/04/94 1605

— 76

— 21 256 .02

— 5.7 <.010 1.2

(MLS4) 04/05/94 0830

— 74

— 22 308 .02 7.18 7.2 .02 1.1

04/05/94 1450

— 88

— 20 339 .03 7.46 7.8 .34 .95

04/06/94 0820

— 127

— 21 166 .07 7.9 9 1.1 1

04/07/94 1144

— 135

— 21 153 .86 6.7 8 1.3 1.2

04/08/94 1125

— 137

— 21 169 .36 7.37 8.2 .83 1.2

04/21/94 1145

— 128

— 21 149 2 1.87 2.1 .23 1.2

06/01/94 0915

— 142

— 22 95 1.5 .17 .19 .02 2.3

2S/11W-18L27 04/04/94 1905 0.14 97 0.3 22 150 .03 1.48 1.5 .02 .16(PR8 at 49 ft) 04/05/94 1700 .14 100 .3 22 150

—

— 1.4

—

—

04/06/94 1030

— 99

— 21 151 .03 1.49 1.5 .01 .17

04/07/94 1425

— 98

— 21 149 .02

— 1.5 <.010 .17

04/08/94 1040

— 102

— 22 151 .02

— 1.7 <.010 .16

04/21/94 1740 .14 96 .3 22 150 .02 2.17 2.2 .03 .1506/01/94 1330 .15 94 .4 21 150 .03 1.38 1.4 .02 .18

2S/11W-18L28 04/04/94 1720

— 107

— 23 158 .01

— 1.3 <.010 .06

Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus—Continued

Station name

(Local Identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L 

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

mg/L as N

(00613)

Phosphorus, 

ortho

phosphate, 

dissolved 

(mg/L as P)

(00671)
Appendixes 203

(PR9 at 25 ft) 04/05/94 1805 — 107 — 23 156 0.02 1.49 1.5 0.01 0.06

04/06/94 1205 — 109 — 23 159 .02 2.48 2.6 .12 .0604/07/94 1200 — 123 — 22 156 .02 5.9 6.9 1 .0604/08/94 1000 — 130 — 22 152 .02 6.2 7.7 1.5 .0604/21/94 1625 — 123 — 20 140 .03 6.4 8.2 1.8 .0706/01/94 1515 — 123 — 21 142 .03 4.8 6 1.2 .08

2S/11W-18L29 04/04/94 2000 — 109 — 22 158 .02 1.28 1.3 .02 .1(PR10 at 50 ft) 04/05/94 1405 — 109 — 22 157 .03 1.28 1.3 .02 .11

04/06/94 1550 — 109 — 21 156 .03 1.28 1.3 .02 .1104/07/94 1030 — 108 — 21 155 .02 1.39 1.4 .01 .104/07/94 1200 — — — — — — — — — —04/08/94 1200 — 109 — 22 157 .03 — 1.5 <.010 .1204/21/94 1445 — 103 — 21 — .02 1.49 1.5 .01 .106/01/94 1130 — 101 — 21 154 .02 1.68 1.7 .02 .1

2S/11W-18L30 04/04/94 1550 — 99 — 21 156 .03 — 1.4 <.010 .48(PR11 at 36 ft) 04/05/94 1550 — 99 — 21 156 .03 1.39 1.4 .01 .46

04/06/94 1445 — 102 — 21 158 .02 — 1.5 <.010 .4104/07/94 0930 — 105 — 22 158 .02 2.7 2.8 .1 .3804/07/94 0931 0.15 100 0.4 22 160 .03 2.7 2.8 .1 .3804/08/94 1200 — 130 — 22 — .02 5.7 6.9 1.2 .3504/21/94 1315 — 125 — 20 140 .02 4.9 7.2 2.3 .3506/01/94 1015 — 108 — 21 146 .01 4.09 4.5 .41 .32

POND AT PICO 04/05/94 0845 — 131 — 20 150 4.7 5.3 6.8 1.5 1.9(PR12) 04/05/94 0943 — 130 — 20 149 4.7 5.4 6.9 1.5 1.8

04/05/94 1055 — 129 — 20 151 4.7 5.2 6.7 1.5 204/05/94 1154 — 128 — 20 150 4.3 5.4 6.8 1.4 1.804/05/94 1421 — 125 — 20 149 3.2 6 7.2 1.2 204/05/94 1607 — 129 — 20 147 3.9 6.2 7.4 1.2 1.9

Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus—Continued

Station name

(Local Identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L 

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

mg/L as N

(00613)

Phosphorus, 

ortho

phosphate, 

dissolved 

(mg/L as P)

(00671)
204 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/05/94 1714

— 131

— 20 150 4.6 6.3 7.5 1.2 2.2

04/05/94 1830

— 134

— 20 150 5.3 6.6 7.8 1.2 2.2

04/06/94 0745

— 133

— 20 149 6 5.9 7.3 1.4 2.2

04/07/94 0800

— 137

— 20 146 5.1 6.1 7.7 1.6 2

04/07/94 0805

— 137

— 20 147 5.2 6.3 7.9 1.6 2

04/07/94 0810

— 138

— 20 148 5.2 6.1 7.8 1.7 2

04/07/94 1430

— 135

— 20 144 4.5 6 7.6 1.6 2

04/07/94 1530

— 137

— 20 145 4.5 6.2 7.8 1.6 2

04/07/94 1540

— 136

— 20 144 4.5 6 7.7 1.7 2

04/07/94 1825

— 139

— 20 145 5 6.3 7.9 1.6 2

04/07/94 1830

— 138

— 20 145 5.1 6.1 7.8 1.7 2

04/07/94 1845

— 137

— 20 144

—

—

—

—

—

04/08/94 1130 0.04 130 0.7 20 140 5.6 12.3 14 1.7 204/21/94 0800

— 129

— 20 140 2.6 6.3 7.2 .9 1.9

04/21/94 0815

— 129

— 20 140 2.5 4.6 7.1 2.5 1.8

04/21/94 0820

— 129

— 19 138 2.6 6.12 7 .88 1.9

04/21/94 0825

— 129

— 20 139 2.6 6.1 7 .9 1.9

SEWAGE EFFLUENT 04/05/94 0915

— 127

— 20 141 4.9 4.7 6.3 1.6 1.7

(PR13) 04/05/94 1020

— 131

— 20 149 2.8 6 7 1 2.1

04/05/94 1105

— 123

— 20 142 3.4 5.3 6.8 1.5 1.5

04/05/94 1210

— 120

— 20 148

—

—

—

—

—

04/05/94 1420

— 134

— 20 149 3.3 6.8 7.9 1.1 2.1

04/05/94 1545

— 141

— 20 148 6.6 6.6 7.8 1.2 2.3

04/05/94 1650

— 140

— 20 148 8 6.9 8.1 1.2 2.3

04/05/94 1835

— 140

— 19 148 9 7.9 9.2 1.3 2.4

04/06/94 1215 .1 120 .5 20 150 2.5 8.4 9.5 1.1 2.104/07/94 1215

— 124

— 20 140 2.9 5.7 6.8 1.1 1.7

04/08/94 1215

— 118

— 20 142 3 6.5 7.7 1.2 1.7

04/21/94 1530

— 136

— 20 134 8 4.3 5.4 1.1 2.1

Appendix 3B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, bromide–phosphorus—Continued

Station name

(Local Identifier) Date Time

Bromide, 

dissolved 

(mg/L

as Br)

(71870)

Chloride, 

dissolved 

(mg/L 

as Cl)

(00940)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

mg/L as N

(00613)

Phosphorus, 

ortho

phosphate, 

dissolved 

(mg/L as P)

(00671)
Appendixes 205

Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt—Continued

Station name

(Local identifier) Date Time

Barium,

dissolved 

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt,

dissolved 

(μg/L as Co)

(01035)

2S/11W-18L14A 04/04/94 1940 220 <0.5 <1 <5 6(MLS20) 04/05/94 1205 210 <.5 1 <5 8

04/05/94 1800 210 <.5 <1 <5 504/06/94 1400 220 <.5 <1 <5 504/07/94 0900 240 <.5 <1 <5 504/08/94 0825 250 <.5 <1 <5 <304/21/94 0915 220 <.5 <1 <5 <306/01/94 1455 190 <.5 <1 <5 <3

2S/11W-18L14C 04/07/94 0915 190 <.5 3 <5 <3(MLS18) 04/08/94 0830 190 <.5 <1 <5 <32S/11W-18L14F 04/04/94 1930 210 <.5 <1 <5 5(MLS15) 04/05/94 1145 200 1.1 1 <5 4

04/05/94 1750 190 1.1 1 <5 404/06/94 1350 210 <.5 <1 <5 <304/07/94 0945 190 <.5 <1 <5 <304/08/94 0845 230 <.5 <1 <5 <304/21/94 0945 180 <.5 2 <5 <306/01/94 1435 180 <.5 <1 <5 <3

2S/11W-18L14K 04/04/94 1855 130 <.5 <1 <5 <3(MLS10) 04/05/94 1123 130 1.1 2 <5 <3

04/05/94 1740 130 <.5 1 <5 <304/06/94 1145 150 <.5 1 <5 <304/07/94 1000 140 <.5 <1 <5 404/08/94 0910 130 <.5 <1 <5 <304/21/94 1000 140 <.5 2 <5 <306/01/94 1350 150 <.5 1 <5 <3

2S/11W-18L14L 04/04/94 1835 120 <.5 <1 <5 <3(MLS9) 04/05/94 1100 120 1.2 <1 <5 <3

Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, no data; MLS, multilevel sampler]
206 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/05/94 1645 120 1.2 1 <5 <3 04/06/94 1125 140 <.5 2 <5 <3 04/07/94 1018 130 <.5 <1 <5 <3 04/08/94 0945 130 <.5 1 <5 <3 04/21/94 1020 130 <.5 <1 <5 <3 06/01/94 1315 150 <.5 <1 <5 <3 2S/11W-18L14M 04/04/94 1750 160 <.5 <1 <5 <3 (MLS8) 04/05/94 1046 160 1.2 1 <5 <3 04/05/94 1635 160 1.3 1 <5 <3 04/06/94 1045 170 <.5 1 <5 <3 04/07/94 1040 150 <.5 <1 <5 <3 04/08/94 0930 180 <.5 <1 <5 <3 04/21/94 1040 150 <.5 <1 <5 <3 06/01/94 1210 160 <.5 <1 <5 <3 2S/11W-18L14N 04/04/94 1730 150 <.5 1 <5 <3 (MLS7) 04/05/94 1010 150 1.2 2 <5 <3 04/05/94 1540 150 <.5 1 <5 3 04/06/94 1000 170 <.5 <1 <5 <3 04/07/94 1100 160 <.5 <1 <5 <3 04/08/94 0950 170 <.5 2 <5 <3 04/21/94 1050 150 <.5 2 <5 <3 06/01/94 1100 160 <.5 <1 <5 3 2S/11W-18L14O 04/04/94 1715 160 <.5 2 <5 <3 (MLS6) 04/05/94 0950 150 1.1 <1 <5 <3 04/05/94 1532 160 1.1 1 <5 <3 04/06/94 0950 180 <.5 <1 <5 4 04/07/94 1120 160 <.5 <1 <5 <3 04/08/94 1045 180 <.5 5 <5 <3 04/21/94 1105 170 <.5 <1 <5 <3 06/01/94 1040 160 <.5 <1 <5 <3 Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt—Continued Station name (Local identifier) Date Time Barium, dissolved 

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt,

dissolved 

(μg/L as Co)

(01035)
Appendixes 207

2S/11W-18L14P 04/04/94 1630 160 <0.5 1 <5 <3(MLS5) 04/05/94 0900 160 1 <1 <5 4

04/05/94 1505 170 1 <1 <5 <304/06/94 0818 170 <.5 <1 <5 <304/07/94 1130 160 <.5 <1 <5 <304/08/94 1055 180 <.5 <1 <5 <304/21/94 1135 160 <.5 <1 <5 <306/01/94 0935 160 <.5 <1 <5 <3

2S/11W-18L14Q 04/04/94 1605 160 <.5 <1 <5 <3(MLS4) 04/05/94 0830 170 <.5 <1 <5 <3

04/05/94 1450 190 <.5 <1 <5 <304/06/94 0820 140 <.5 <1 <5 <304/07/94 1144 140 <.5 <1 <5 <304/08/94 1125 180 <.5 3 <5 <304/21/94 1145 130 <.5 <1 <5 <306/01/94 0915 140 <.5 1 <5 3

2S/11W-18L27 04/04/94 1905 140 <.5 1 <5 11(PR8 at 49 ft) 04/05/94 1700 140 <.5 <1 <5 12

04/06/94 1030 140 <.5 <1 <5 1304/07/94 1425 140 <.5 <1 <5 1004/08/94 1040 150 <.5 <1 <5 904/21/94 1740 140 <.5 2 <5 1306/01/94 1330 140 <.5 <1 <5 14

2S/11W-18L28 04/04/94 1720 150 <.5 1 <5 6(PR9 at 25 ft) 04/05/94 1805 150 1 <1 <5 5

04/06/94 1205 150 <.5 <1 <5 404/07/94 1200 170 <.5 <1 <5 504/08/94 1000 170 <.5 <1 <5 <304/21/94 1625 130 <.5 <1 <5 <306/01/94 1515 150 <.5 <1 <5 <3

Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt—Continued

Station name

(Local identifier) Date Time

Barium,

dissolved 

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt,

dissolved 

(μg/L as Co)

(01035)
208 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L29 04/04/94 2000 150 <0.5 <1 <5 8 (PR10 at 50 ft) 04/05/94 1405 150 1 2 <5 10 04/06/94 1550 150 <.5 <1 <5 12 04/07/94 1030 150 <.5 2 <5 11 04/07/94 1200

—

—

—

—

—

04/08/94 1200 160 <.5 <1 <5 1004/21/94 1445 150 <.5 <1 <5 1406/01/94 1130 150 <.5 <1 <5 10

2S/11W-18L30 04/04/94 1550 140 <.5 3 <5 4(PR11 at 36 ft) 04/05/94 1550 130 <.5 <1 <5 5

04/06/94 1445 140 <.5 <1 <5 <304/07/94 0930 150 <.5 2 <5 604/07/94 0931 150 <.5 2 <5 404/08/94 1200 170 <.5 3 <5 <304/21/94 1315 140 <.5 <1 <5 <306/01/94 1015 140 <.5 <1 <5 <3

POND AT PICO 04/05/94 0845 42 1.3 <1 <5 <3(PR12) 04/05/94 0943 40 1.1 <1 <5 <3

04/05/94 1055 40 1.2 1 <5 <304/05/94 1154 41 1.2 <1 <5 <304/05/94 1421 40 <.5 <1 <5 <304/05/94 1607 41 <.5 <1 <5 <304/05/94 1714 42 <.5 2 <5 <304/05/94 1830 43 1.1 <1 <5 <304/06/94 0745 43 <.5 <1 <5 <304/07/94 0800 42 <.5 <1 <5 <304/07/94 0805 41 1.3 <1 <5 <304/07/94 0810 42 <.5 3 <5 <304/07/94 1430 41 <.5 <1 <5 <304/07/94 1530 41 <.5 2 <5 <304/07/94 1540 39 <.5 <1 <5 <3

Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt—Continued

Station name

(Local identifier) Date Time

Barium,

dissolved 

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt,

dissolved 

(μg/L as Co)

(01035)
Appendixes 209

04/07/94 1825 40 <0.5 2 <5 304/07/94 1830 41 <.5 4 <5 <304/07/94 1845 41 <.5 <1 <5 <304/08/94 1130 41 <.5 2 <5 <304/21/94 0800 41 <.5 <1 <5 <304/21/94 0815 42 <.5 <1 <5 <304/21/94 0820 40 <.5 1 <5 <304/21/94 0825 41 <.5 1 <5 <3

SEWAGE EFFLUENT 04/05/94 0915 38 <.5 2 <5 <3(PR13) 04/05/94 1020 39 <.5 2 5 <3

04/05/94 1105 35 1.2 <1 <5 <304/05/94 1210 39 <.5 <1 <5 <304/05/94 1420 40 1.1 2 <5 <304/05/94 1545 41 <.5 <1 <5 <304/05/94 1650 42 1.1 <1 <5 <304/05/94 1835 43 <.5 <1 <5 <304/06/94 1215 38 <.5 <1 <5 <304/07/94 1215 38 <.5 <1 <5 <304/08/94 1215 40 <.5 <1 <5 <304/21/94 1530 43 <.5 <1 <5 <3

Appendix 3C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, barium–cobalt—Continued

Station name

(Local identifier) Date Time

Barium,

dissolved 

(μg/L as Ba)

(01005)

Beryllium, 

dissolved 

(μg/L as Be)

(01010)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

Chromium, 

dissolved

(μg/L as Cr)

(01030)

Cobalt,

dissolved 

(μg/L as Co)

(01035)
210 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese—Continued Station name (Local identifier) Date Time Copper, dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

Lithium, 

dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)

2S/11W-18L14A 04/04/94 1940 <10 330 <10 <4 2,700(MLS20) 04/05/94 1205 <10 310 <10 7 2,600

04/05/94 1800 <10 320 <10 6 2,60004/06/94 1400 <10 190 <10 6 2,00004/07/94 0900 <10 170 10 6 2,00004/08/94 0825 10 110 <10 6 1,90004/21/94 0915 20 86 10 6 1,70006/01/94 1455 <10 68 <10 <4 1,600

2S/11W-18L14C 04/07/94 0915 10 11 <10 11 170(MLS18) 04/08/94 0830 20 9 <10 12 1402S/11W-18L14F 04/04/94 1930 <10 5 <10 8 220(MLS15) 04/05/94 1145 <10 6 <10 13 220

04/05/94 1750 <10 10 <10 12 19004/06/94 1350 10 11 <10 8 7804/07/94 0945 10 14 <10 11 4204/08/94 0845 20 11 <10 11 3004/21/94 0945 20 10 <10 12 8206/01/94 1435 20 9 <10 10 150

2S/11W-18L14K 04/04/94 1855 <10 <3 <10 9 77(MLS10) 04/05/94 1123 <10 <3 <10 12 69

04/05/94 1740 <10 <3 <10 11 6404/06/94 1145 10 14 <10 10 1704/07/94 1000 10 13 <10 11 804/08/94 0910 10 9 <10 12 304/21/94 1000 20 12 10 10 4806/01/94 1350 <10 3 10 10 250

2S/11W-18L14L 04/04/94 1835 <10 <3 20 9 31(MLS9) 04/05/94 1100 <10 6 <10 13 22

Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value 

shown; —, no data; MLS, multilevel sampler]
Appendixes 211

04/05/94 1645 <10 <3 <10 14 1804/06/94 1125 20 12 <10 9 804/07/94 1018 10 10 <10 11 204/08/94 0945 10 12 10 14 304/21/94 1020 20 11 <10 12 5306/01/94 1315 <10 <3 <10 11 190

2S/11W-18L14M 04/04/94 1750 <10 65 <10 8 530(MLS8) 04/05/94 1046 <10 68 <10 12 490

04/05/94 1635 <10 60 <10 12 44004/06/94 1045 10 42 <10 8 37004/07/94 1040 10 23 20 11 22004/08/94 0930 20 28 <10 11 24004/21/94 1040 20 40 <10 11 33006/01/94 1210 <10 39 <10 9 530

2S/11W-18L14N 04/04/94 1730 <10 5 <10 7 760(MLS7) 04/05/94 1010 <10 8 10 12 640

04/05/94 1540 <10 7 <10 11 62004/06/94 1000 <10 13 10 8 60004/07/94 1100 20 17 <10 11 15004/08/94 0950 20 10 <10 10 16004/21/94 1050 10 12 <10 11 25006/01/94 1100 10 3 <10 8 480

2S/11W-18L14O 04/04/94 1715 <10 <3 <10 8 230(MLS6) 04/05/94 0950 <10 5 <10 12 680

04/05/94 1532 <10 4 <10 14 16004/06/94 0950 10 17 <10 8 7904/07/94 1120 10 15 <10 11 3804/08/94 1045 20 13 <10 10 5104/21/94 1105 20 13 <10 11 11006/01/94 1040 10 <3 <10 10 380

Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper,

dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

Lithium, 

dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)
212 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L14P 04/04/94 1630 <10 11 <10 8 260 (MLS5) 04/05/94 0900 <10 6 <10 12 230 04/05/94 1505 <10 4 <10 14 190 04/06/94 0818 10 25 30 11 130 04/07/94 1130 20 16 <10 11 46 04/08/94 1055 20 14 <10 13 62 04/21/94 1135 20 16 <10 12 130 06/01/94 0935 10 6 <10 8 420 2S/11W-18L14Q 04/04/94 1605 <10 6 <10 11 16 (MLS4) 04/05/94 0830 <10 <3 <10 13 21 04/05/94 1450 <10 7 10 14 45 04/06/94 0820 10 16 20 18 32 04/07/94 1144 10 16 <10 20 16 04/08/94 1125 20 12 <10 10 48 04/21/94 1145 20 10 <10 15 69 06/01/94 0915 10 3 <10 8 360 2S/11W-18L27 04/04/94 1905 <10 <3 <10 6 960 (PR8 at 49 ft) 04/05/94 1700 <10 <3 <10 6 940 04/06/94 1030 <10 <3 <10 <4 930 04/07/94 1425 <10 5 <10 5 880 04/08/94 1040 <10 <3 <10 <4 950 04/21/94 1740 <10 <3 <10 6 930 06/01/94 1330 <10 6 20 <4 930 2S/11W-18L28 04/04/94 1720 <10 <3 <10 7 15 (PR9 at 25 ft) 04/05/94 1805 <10 <3 <10 10 14 04/06/94 1205 <10 5 <10 6 13 04/07/94 1200 10 7 <10 6 15 04/08/94 1000 20 11 <10 6 14 04/21/94 1625 20 10 20 5 12 06/01/94 1515 20 7 <10 7 36 Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese—Continued Station name (Local identifier) Date Time Copper, dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

Lithium, 

dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 213

2S/11W-18L29 04/04/94 2000 <10 <3 <10 6 1,100(PR10 at 50 ft) 04/05/94 1405 <10 <3 <10 8 1,100

04/06/94 1550 <10 7 <10 4 1,10004/07/94 1030 <10 <3 <10 <4 1,10004/07/94 1200 — — — — —04/08/94 1200 <10 <3 10 <4 1,10004/21/94 1445 <10 4 <10 <4 1,10006/01/94 1130 <10 <3 <10 <4 1,100

2S/11W-18L30 04/04/94 1550 <10 <3 <10 8 74(PR11 at 36 ft) 04/05/94 1550 <10 <3 10 11 72

04/06/94 1445 <10 4 <10 9 7904/07/94 0930 <10 4 30 10 8804/07/94 0931 <10 6 <10 13 9004/08/94 1200 10 9 <10 10 11004/21/94 1315 20 12 <10 9 9406/01/94 1015 10 5 <10 7 120

POND AT PICO 04/05/94 0845 <10 35 <10 19 23(PR12) 04/05/94 0943 <10 28 <10 19 22

04/05/94 1055 <10 37 <10 19 1804/05/94 1154 <10 19 <10 19 1604/05/94 1421 <10 18 <10 18 1404/05/94 1607 <10 17 10 18 1504/05/94 1714 <10 18 <10 18 1404/05/94 1830 <10 16 <10 19 1404/06/94 0745 <10 32 <10 16 1204/07/94 0800 <10 24 <10 16 1104/07/94 0805 <10 28 <10 19 1104/07/94 0810 <10 26 <10 16 1104/07/94 1430 <10 21 <10 15 1104/07/94 1530 <10 20 <10 15 1004/07/94 1540 <10 22 <10 15 11

Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese—Continued

Station name

(Local identifier) Date Time

Copper,

dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

Lithium, 

dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)
214 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/07/94 1825 <10 26 <10 14 11 04/07/94 1830 <10 19 <10 16 10 04/07/94 1845 <10 19 20 15 10 04/08/94 1130 <10 32 <10 19 12 04/21/94 0800 <10 25 <10 14 15 04/21/94 0815 <10 36 <10 15 15 04/21/94 0820 <10 23 <10 15 13 04/21/94 0825 <10 25 <10 14 15 SEWAGE EFFLUENT 04/05/94 0915 <10 36 <10 17 13 (PR13) 04/05/94 1020 <10 34 <10 19 11 04/05/94 1105 <10 29 <10 18 11 04/05/94 1210 <10 30 <10 18 10 04/05/94 1420 <10 27 <10 19 10 04/05/94 1545 <10 23 <10 18 9 04/05/94 1650 <10 25 <10 20 10 04/05/94 1835 <10 26 <10 18 13 04/06/94 1215 <10 32 <10 17 13 04/07/94 1215 <10 31 <10 15 11 04/08/94 1215 <10 37 10 16 8 04/21/94 1530 <10 32 <10 13 13 Appendix 3D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, copper–manganese—Continued Station name (Local identifier) Date Time Copper, dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

Lithium, 

dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 215

Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

 Strontium ,

dissolved

(μg/L as Sr)

(01080)

2S/11W-18L14A 04/04/94 1940 <10 <10 <1 790(MLS20) 04/05/94 1205 20 <10 <1 810

04/05/94 1800 <10 10 <1 80004/06/94 1400 <10 <10 <1 81004/07/94 0900 <10 10 <1 86004/08/94 0825 <10 <10 1 89004/21/94 0915 20 <10 1 73006/01/94 1455 30 <10 <1 670

2S/11W-18L14C 04/07/94 0915 10 <10 <1 650(MLS18) 04/08/94 0830 10 <10 <1 6502S/11W-18L14F 04/04/94 1930 <10 <10 <1 760(MLS15) 04/05/94 1145 <10 <10 <1 740

04/05/94 1750 <10 <10 <1 72004/06/94 1350 20 <10 <1 73004/07/94 0945 <10 <10 <1 66004/08/94 0845 <10 <10 <1 80004/21/94 0945 20 <10 2 55006/01/94 1435 20 <10 <1 600

2S/11W-18L14K 04/04/94 1855 20 <10 <1 520(MLS10) 04/05/94 1123 20 <10 <1 540

04/05/94 1740 20 <10 <1 56004/06/94 1145 <10 <10 <1 62004/07/94 1000 <10 <10 <1 55004/08/94 0910 10 <10 <1 55004/21/94 1000 30 <10 <1 49006/01/94 1350 30 <10 <1 610

2S/11W-18L14L 04/04/94 1835 <10 <10 <1 520(MLS9) 04/05/94 1100 10 <10 <1 540

Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, 

no data; MLS, multilevel sampler]
216 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/05/94 1645 20 <10 2 530 04/06/94 1125 20 <10 <1 610 04/07/94 1018 <10 <10 <1 540 04/08/94 0945 10 <10 1 530 04/21/94 1020 10 <10 <1 470 06/01/94 1315 10 <10 <1 610 2S/11W-18L14M 04/04/94 1750 <10 <10 <1 620 (MLS8) 04/05/94 1046 <10 <10 <1 620 04/05/94 1635 20 <10 <1 620 04/06/94 1045 30 <10 2 650 04/07/94 1040 <10 <10 <1 550 04/08/94 0930 20 <10 <1 670 04/21/94 1040 20 <10 <1 500 06/01/94 1210 30 10 <1 570 2S/11W-18L14N 04/04/94 1730 20 <10 <1 550 (MLS7) 04/05/94 1010 10 <10 <1 520 04/05/94 1540 20 <10 <1 540 04/06/94 1000 <10 <10 <1 590 04/07/94 1100 <10 <10 <1 540 04/08/94 0950 10 <10 <1 570 04/21/94 1050 30 <10 <1 470 06/01/94 1100 20 <10 <1 540 2S/11W-18L14O 04/04/94 1715 20 <10 <1 540 (MLS6) 04/05/94 0950 <10 <10 <1 540 04/05/94 1532 10 <10 <1 560 04/06/94 0950 <10 <10 <1 600 04/07/94 1120 <10 <10 <1 530 04/08/94 1045 30 <10 <1 580 04/21/94 1105 20 <10 <1 490 06/01/94 1040 20 <10 1 520 Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium—Continued Station name (Local identifier) Date Time Molybdenum, dissolved 

(μg/L as Mo)

(01060)

 Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

 Strontium ,

dissolved

(μg/L as Sr)

(01080)
Appendixes 217

2S/11W-18L14P 04/04/94 1630 <10 <10 <1 590(MLS5) 04/05/94 0900 10 <10 <1 580

04/05/94 1505 <10 <10 <1 59004/06/94 0818 <10 <10 <1 60004/07/94 1130 <10 <10 <1 52004/08/94 1055 20 <10 <1 61004/21/94 1135 30 <10 <1 49006/01/94 0935 30 <10 <1 570

2S/11W-18L14Q 04/04/94 1605 <10 <10 <1 520(MLS4) 04/05/94 0830 10 <10 <1 560

04/05/94 1450 10 <10 <1 70004/06/94 0820 <10 <10 <1 46004/07/94 1144 20 <10 1 44004/08/94 1125 30 <10 <1 58004/21/94 1145 10 <10 <1 45006/01/94 0915 40 10 <1 490

2S/11W-18L27 04/04/94 1905 20 <10 2 780(PR8 at 49 ft) 04/05/94 1700 10 <10 <1 770

04/06/94 1030 <10 <10 2 77004/07/94 1425 <10 <10 <1 76004/08/94 1040 10 <10 1 80004/21/94 1740 10 <10 <1 81006/01/94 1330 <10 <10 <1 750

2S/11W-18L28 04/04/94 1720 <10 10 <1 890(PR9 at 25 ft) 04/05/94 1805 <10 <10 <1 850

04/06/94 1205 <10 <10 <1 87004/07/94 1200 10 10 <1 91004/08/94 1000 <10 <10 1 92004/21/94 1625 10 <10 <1 71006/01/94 1515 20 <10 <1 810

Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

 Strontium ,

dissolved

(μg/L as Sr)

(01080)
218 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 2S/11W-18L29 04/04/94 2000 <10 <10 <1 860 (PR10 at 50 ft) 04/05/94 1405 10 <10 1 840 04/06/94 1550 <10 <10 <1 850 04/07/94 1030 <10 <10 <1 820 04/07/94 1200

—

—

—

—

04/08/94 1200 20 <10 <1 86004/21/94 1445 10 <10 <1 84006/01/94 1130 10 <10 <1 810

2S/11W-18L30 04/04/94 1550 30 <10 <1 640(PR11 at 36 ft) 04/05/94 1550 30 10 <1 630

04/06/94 1445 <10 <10 <1 65004/07/94 0930 20 <10 <1 66004/07/94 0931 10 <10 <1 69004/08/94 1200 20 <10 <1 76004/21/94 1315 20 <10 <1 61006/01/94 1015 20 <10 <1 640

POND AT PICO 04/05/94 0845 10 <10 <1 520(PR12) 04/05/94 0943 20 <10 <1 520

04/05/94 1055 20 <10 <1 52004/05/94 1154 10 <10 <1 52004/05/94 1421 20 <10 <1 52004/05/94 1607 20 <10 <1 53004/05/94 1714 10 <10 <1 52004/05/94 1830 10 10 <1 54004/06/94 0745 <10 <10 <1 54004/07/94 0800 20 10 <1 52004/07/94 0805 20 <10 <1 53004/07/94 0810 30 10 <1 52004/07/94 1430 20 <10 <1 51004/07/94 1530 10 <10 <1 51004/07/94 1540 <10 <10 <1 510

Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

 Strontium ,

dissolved

(μg/L as Sr)

(01080)
Appendixes 219

04/07/94 1825 <10 <10 <1 51004/07/94 1830 10 10 <1 52004/07/94 1845 10 <10 <1 52004/08/94 1130 20 <10 1 53004/21/94 0800 <10 <10 <1 51004/21/94 0815 20 <10 1 51004/21/94 0820 20 <10 <1 50004/21/94 0825 20 <10 <1 510

SEWAGE EFFLUENT 04/05/94 0915 20 <10 2 500(PR13) 04/05/94 1020 30 <10 2 520

04/05/94 1105 20 <10 <1 49004/05/94 1210 20 <10 <1 52004/05/94 1420 10 <10 1 54004/05/94 1545 20 <10 <1 54004/05/94 1650 10 <10 <1 55004/05/94 1835 10 10 <1 54004/06/94 1215 10 <10 <1 52004/07/94 1215 <10 <10 <1 50004/08/94 1215 40 10 <1 52004/21/94 1530 <10 <10 <1 510

Appendix 3E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, molybdenum–strontium—Continued

Station name

(Local identifier) Date Time

 Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

 Strontium ,

dissolved

(μg/L as Sr)

(01080)
220 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen 16/18—Continued Station name (Local identifier) Date Time Vanadium, dissolved

(μg/L as V)

(01085)

 Zinc ,

dissolved 

(μg/L as Zn)

(01090)

Hydrogen-2/1 

(per mil)

(82082)

 Nitrogen-15/14, 

ammonium 

fraction

(per mil)

(82691)

 Nitrogen-15/14, 

nitrate fraction, 

(per mil)

(82690)

 Oxygen-18/16,

(per mil)

(82085)

2S/11W-18L14A 04/04/94 1940 <6 <3 −57.6

— 47.1

−7.94

(MLS20) 04/05/94 1205 <6 8 —

—

—

—

04/05/94 1800 <6 11

—

—

—

—

04/06/94 1400 <6 10

—

—

—

—

04/07/94 0900 <6 7 —

—

—

—

04/08/94 0825 <6 8 —

—

—

—

04/21/94 0915 <6 <3 —

—

—

—

06/01/94 1455 <6 14

—

—

—

—

2S/11W-18L14C 04/07/94 0915 8 56

—

—

—

—

(MLS18) 04/08/94 0830 11 120

—

—

—

—

2S/11W-18L14F 04/04/94 1930 <6 7 −57.7

— 53.3

−7.99

(MLS15) 04/05/94 1145 <6 8 —

—

—

—

04/05/94 1750 6 9 —

—

—

—

04/06/94 1350 <6 13

—

—

—

—

04/07/94 0945 10 23

—

—

—

—

04/08/94 0845 9 11

—

—

—

—

04/21/94 0945 11 16

—

—

—

—

06/01/94 1435 <6 18

—

—

—

—

2S/11W-18L14K 04/04/94 1855 6 <3 −55.3

— 40.4

−7.79

(MLS10) 04/05/94 1123 <6 7 —

—

—

—

04/05/94 1740 7 4 —

—

—

—

04/06/94 1145 6 34

−62.7

— 7.6

−8.59

04/07/94 1000 9 33

—

—

—

—

04/08/94 0910 7 15

—

—

—

—

04/21/94 1000 9 <3 —

—

—

—

06/01/94 1350 <6 15

−55.0

— 65.3

−7.68

Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen-18/16[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; per mil, part per thousand; <, actual value 

less than value shown; —, no data; MLS, multilevel sampler]
Appendixes 221

2S/11W-18L14L 04/04/94 1835 <6 <3 −55.5 — 39.3 −7.74(MLS9) 04/05/94 1100 <6 <3 — — — —

04/05/94 1645 <6 5 — — — —04/06/94 1125 <6 17 −61.5 — 8.1 −8.5704/07/94 1018 8 20 — — — —04/08/94 0945 7 16 — — — —04/21/94 1020 9 5 — — — —06/01/94 1315 <6 11 −55.0 — 66.7 −7.72

2S/11W-18L14M 04/04/94 1750 <6 14 −56.5 — 41.7 −7.81(MLS8) 04/05/94 1046 <6 18 — — — —

04/05/94 1635 <6 15 — — — —04/06/94 1045 7 23 −61.8 — 9.5 −8.3804/07/94 1040 11 73 — — — —04/08/94 0930 10 58 — — — —04/21/94 1040 10 24 — — — —06/01/94 1210 <6 36 −55.6 — 54.3 −7.63

2S/11W-18L14N 04/04/94 1730 <6 5 −55.1 — 31.5 −7.62(MLS7) 04/05/94 1010 <6 9 — — — —

04/05/94 1540 7 15 — — — —04/06/94 1000 6 13 −60.9 — 10.2 −8.3804/07/94 1100 12 34 — — — —04/08/94 0950 11 20 — — — —04/21/94 1050 11 16 — — — —06/01/94 1100 7 7 −54.5 — 60.9 −7.28

2S/11W-18L14O 04/04/94 1715 7 5 −54.4 — 31.5 −7.7(MLS6) 04/05/94 0950 <6 11 — — — —

04/05/94 1532 8 15 — — — —04/06/94 0950 11 22 −61.3 — 9 −8.4504/07/94 1120 11 43 — — — —04/08/94 1045 11 27 — — — —

Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen 16/18—Continued

Station name

(Local identifier) Date Time

Vanadium, 

dissolved

(μg/L as V)

(01085)

 Zinc ,

dissolved 

(μg/L as Zn)

(01090)

Hydrogen-2/1 

(per mil)

(82082)

 Nitrogen-15/14, 

ammonium 

fraction

(per mil)

(82691)

 Nitrogen-15/14, 

nitrate fraction, 

(per mil)

(82690)

 Oxygen-18/16,

(per mil)

(82085)
222 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/21/94 1105 14 18

—

—

—

—

06/01/94 1040 11 16

−54.0

— 52.6

−7.16

2S/11W-18L14P 04/04/94 1630 8 30

−55.3

— 37.8

−7.76

(MLS5) 04/05/94 0900 7 22

—

—

—

—

04/05/94 1505 7 35

—

—

—

—

04/06/94 0818 9 36

−61.3

— 10.9

−8.32

04/07/94 1130 14 47

—

—

—

—

04/08/94 1055 12 31

—

—

—

—

04/21/94 1135 13 18

—

—

—

—

06/01/94 0935 9 29

−54.2

— 52.6

−7.16

2S/11W-18L14Q 04/04/94 1605 14 <3 −50.6

— 22.9

−7.15

(MLS4) 04/05/94 0830 10 4 —

—

—

—

04/05/94 1450 10 19

—

—

—

—

04/06/94 0820 11 30

−61.8

—

—

−8.50

04/07/94 1144 13 34

—

—

—

—

04/08/94 1125 9 34

—

—

—

—

04/21/94 1145 13 15

—

—

—

—

06/01/94 0915 10 26

−45.4 28.8

−5.03

2S/11W-18L27 04/04/94 1905 9 4 —

— 41.2

—

(PR8 at 49 ft) 04/05/94 1700 10 <3 —

—

—

04/06/94 1030 6 9 −57.8

— 41.8

−7.96

04/07/94 1425 <6 <3 —

—

—

—

04/08/94 1040 <6 6 —

—

—

—

04/21/94 1740 9 <3 —

—

—

—

06/01/94 1330 <6 20

—

—

—

—

2S/11W-18L28 04/04/94 1720 <6 <3 −56.8

— 50.9

−7.99

(PR9 at 25 ft) 04/05/94 1805 <6 4 —

—

—

—

04/06/94 1205 <6 6 —

—

—

—

04/07/94 1200 7 <3 —

—

—

—

04/08/94 1000 7 4 —

—

—

—

Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen 16/18—Continued

Station name

(Local identifier) Date Time

Vanadium, 

dissolved

(μg/L as V)

(01085)

 Zinc ,

dissolved 

(μg/L as Zn)

(01090)

Hydrogen-2/1 

(per mil)

(82082)

 Nitrogen-15/14, 

ammonium 

fraction

(per mil)

(82691)

 Nitrogen-15/14, 

nitrate fraction, 

(per mil)

(82690)

 Oxygen-18/16,

(per mil)

(82085)
Appendixes 223

04/21/94 1625 <6 5 — — — —06/01/94 1515 <6 4 — — — —

2S/11W-18L29 04/04/94 2000 <6 <3 — — — —(PR10 at 50 ft) 04/05/94 1405 <6 9 — — — —

04/06/94 1550 6 10 — — — —04/07/94 1030 <6 <3 — — — —04/07/94 1200 — — — — — —04/08/94 1200 <6 4 — — — —04/21/94 1445 <6 <3 — — — —06/01/94 1130 <6 14 — — — —

2S/11W-18L30 04/04/94 1550 7 7 — — — —(PR11 at 36 ft) 04/05/94 1550 9 <3 — — — —

04/06/94 1445 9 <3 — — — —04/07/94 0930 9 <3 — — — —04/07/94 0931 11 <3 — — — —04/08/94 1200 7 <3 — — — —04/21/94 1315 9 <3 — — — —06/01/94 1015 6 17 — — — —

POND AT PICO 04/05/94 0845 <6 48 — — — —(PR12) 04/05/94 0943 <6 42 — — — —

04/05/94 1055 <6 42 — — — —04/05/94 1154 <6 42 — — — —04/05/94 1421 <6 43 — — — —04/05/94 1607 <6 41 — — — —04/05/94 1714 <6 51 — — — —04/05/94 1830 <6 52 — — — —04/06/94 0745 <6 58 — — 9.4 —04/07/94 0800 <6 50 — — — —04/07/94 0805 <6 55 — — — —04/07/94 0810 <6 47 — — — —

Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen 16/18—Continued

Station name

(Local identifier) Date Time

Vanadium, 

dissolved

(μg/L as V)

(01085)

 Zinc ,

dissolved 

(μg/L as Zn)

(01090)

Hydrogen-2/1 

(per mil)

(82082)

 Nitrogen-15/14, 

ammonium 

fraction

(per mil)

(82691)

 Nitrogen-15/14, 

nitrate fraction, 

(per mil)

(82690)

 Oxygen-18/16,

(per mil)

(82085)
224 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 04/07/94 1430 <6 50

—

—

—

—

04/07/94 1530 <6 39

—

—

—

—

04/07/94 1540 <6 49

—

—

—

—

04/07/94 1825 <6 58

—

—

—

—

04/07/94 1830 <6 45

—

—

—

—

04/07/94 1845 <6 58

—

—

—

—

04/08/94 1130 <6 59

—

—

—

—

04/21/94 0800 6 56

—

—

—

—

04/21/94 0815 <6 57

—

—

—

—

04/21/94 0820 <6 44

—

—

—

—

04/21/94 0825 <6 57

—

—

—

—

SEWAGE EFFLUENT 04/05/94 0915 <6 47

—

—

—

—

(PR13) 04/05/94 1020 7 48

—

—

—

—

04/05/94 1105 <6 45

—

—

—

—

04/05/94 1210 <6 55

—

—

—

—

04/05/94 1420 <6 49

—

—

—

—

04/05/94 1545 <6 52

—

—

—

—

04/05/94 1650 <6 44

—

—

—

—

04/05/94 1835 <6 44

—

—

—

—

04/06/94 1215 <6 52

−62.7

— 14.9

−8.65

04/07/94 1215 7 47

—

—

—

—

04/08/94 1215 <6 48

—

—

—

—

04/21/94 1530 <6 38

—

—

—

—

Appendix 3F. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during April and June 1994, vanadium–oxygen 16/18—Continued

Station name

(Local identifier) Date Time

Vanadium, 

dissolved

(μg/L as V)

(01085)

 Zinc ,

dissolved 

(μg/L as Zn)

(01090)

Hydrogen-2/1 

(per mil)

(82082)

 Nitrogen-15/14, 

ammonium 

fraction

(per mil)

(82691)

 Nitrogen-15/14, 

nitrate fraction, 

(per mil)

(82690)

 Oxygen-18/16,

(per mil)

(82085)
Appendixes 225

Appendix 4A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, oxygen–alkalinity—

Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

 pH, water, 

whole, field 

(standard 

units)

(00400)

Specific 

conductance, field

(μS/cm )

(00095)

Water 

temperature

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

 Sodium, 

dissolved 

(mg/L as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field 

(mg/L

as CaCO3) 

(39036)

2S/11W-18L14 A 09/06/94 1530 0.4 7.2 1,080 21.6 — — — — 160(MLS20) 09/07/94 0915 2.4 7 1,180 23.6 — — — — 170

09/09/94 1030 .4 7.2 1,090 28.2 — — — — 17009/12/94 0845 .4 7.2 1,060 27.8 — — — — 18009/16/94 0830 — 7.2 1,090 27.7 — — — — 19009/19/94 1425 .4 7.2 1,070 27.9 — — — — 18009/22/94 0915 .6 7.2 1,070 27.5 — — — — 180

2S/11W-18L14E 09/06/94 1325 .2 7.1 1,150 21.3 — — — — 170(MLS16)2S/11W-18L14F 09/07/94 1035 6 7 1,070 27.5 — — — — 170(MLS15) 09/09/94 1000 .4 7.2 1,100 28.2 — — — — 180

09/12/94 0850 .4 7.2 1,020 27.8 — — — — 18009/16/94 0900 7.2 1,100 27.6 — — — — 19009/19/94 1430 .4 7.1 1,050 27.9 — — — — 17009/21/94 1145 1.2 7.2 1,090 27.5 230 62 18 120 18009/22/94 0920 .6 7.2 1,090 27.3 — — — — 180

2S/11W-18L14I 09/16/94 1000 — 7.2 1,090 27.8 — — — — 190(MLS12) 09/19/94 1545 1 7.1 1,040 27.9 — — — — 1802S/11W-18L14J 09/07/94 1215 6 7 1,070 27.9 — — — — 180(MLS11) 09/12/94 1040 .4 7.2 1,010 27.4 — — — — 1802S/11W-18L14K 09/09/94 1230 .8 7.1 1,080 28.7 — — — — 180(MLS10)2S/11W-18L27 09/06/94 1440 .4 7.1 996 21.8 — — — — 150(PR8 at 49 ft) 09/07/94 1150 .4 7.1 997 21.9 — — — — 150

09/09/94 1330 .6 7.1 1,020 22.1 — — — — 150

Appendix 4A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, oxygen–alkalinity[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; μS/cm, microsiemens per centimeter; oC, degrees Celsius; ft, feet below basin floor or land surface; mg/L, 

milligrams per liter; —, no data; MLS, multilevel sampler]
226 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 09/12/94 1320 .6 7.1 1,040 21.4

—

—

—

— 160

09/16/94 1150

— 7.1 1,040 24.3

—

—

—

— 170

09/19/94 2005 2 7 1,080 23.8

—

—

—

— 180

09/22/94 1215 .6 7 1,040 26.3

—

—

—

— 180

2S/11W-18L28 09/06/94 1210 .6 7 1,060 21.5

—

—

—

— 150

(PR9 at 25 ft) 09/07/94 0945 3.6 7.1 1,050 26.2

—

—

—

— 170

09/09/94 1045 .8 7.1 1,090 29.2

—

—

—

— 180

09/12/94 1430 .4 7.1 1,020 28.5

—

—

—

— 180

09/16/94 1325

— 7 1,100 28.2

—

—

—

— 190

09/19/94 1815 .6 7.1 1,060 27.4 230 61 18 110 17009/22/94 1330 .6 7.2 1,090 28.4

—

—

—

— 180

2S/11W-18L29 09/06/94 1620 .8 7.1 940 22.2

—

—

—

— 170

(PR10 at 60 ft) 09/07/94 1435 .4 7.1 942 21.9

—

—

—

— 160

09/09/94 1530 .4 7.1 938 22.1

—

—

—

— 160

09/12/94 1000 .6 7.1 943 20.6

—

—

—

— 160

09/16/94 1055

— 7.1 999 20.8

—

—

—

— 150

09/19/94 1415 .4 7.1 1,040 20.6

—

—

—

— 150

09/22/94 0930 .6 7 1,050 20.7

—

—

—

— 160

2S/11W-18L30 09/06/94 1835 .8 7 1,060 20.5

—

—

—

— 120

(PR11 at 36 ft) 09/07/94 1630 .4 7 1,090 20.9

—

—

—

— 170

09/09/94 1700 3.6 7.1 1,080 28.3

—

—

—

— 170

09/12/94 1100

— 7.1 1,050 27.8

—

—

—

— 170

09/16/94 0925

— 7.1 1,100 27.5

—

—

—

— 190

09/19/94 1600 .6 7.1 1,060 27.9 230 65 17 120 16009/22/94 1115 .6 7.2 1,080 27.7

—

—

—

— 180

POND AT PICO 09/07/94 1515 6 7.3 1,160 29.7

—

—

—

— 190

 (PR12) 09/09/94 1625

— 7.4 1,170 29.4

—

—

—

— 180

Appendix 4A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, oxygen–alkalinity—

Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

 pH, water, 

whole, field 

(standard 

units)

(00400)

Specific 

conductance, field

(μS/cm )

(00095)

Water 

temperature

(

oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

 Sodium, 

dissolved 

(mg/L as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field 

(mg/L

as CaCO3) 

(39036)
Appendixes 227

09/12/94 1415 6.4 7.3 1,010 28.9 — — — — 17009/16/94 1030 — 7.2 1,080 27.9 — — — — 19009/19/94 1845 4.6 7.1 1,080 27.6 — — — — 16009/22/94 1345 3 7.2 1,080 28.3 — — — — 18009/23/94 1145 7 7.1 1,100 27.8 220 60 18 120 170

Appendix 4A. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, oxygen–alkalinity—

Continued

Station name

(Local identifier) Date Time

Oxygen, 

dissolved 

(mg/L)

(00300)

 pH, water, 

whole, field 

(standard 

units)

(00400)

Specific 

conductance, field

(μS/cm )

(00095)

Water 

temperature

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaCO3)

(00900)

Calcium, 

dissolved 

(mg/L as Ca)

(00915)

Magnesium, 

dissolved 

(mg/L as 

Mg)

(00925)

 Sodium, 

dissolved 

(mg/L as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field 

(mg/L

as CaCO3) 

(39036)
228 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 4B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, bromide–nitrogen—Continued Station name (Local identifier) Date Time Bromide, dissolved (mg/L as Br) (71870) Chloride, dissolved (mg/L as Cl) (00940) Chlorine, total residual (mg/L) (50060) Fluoride, dissolved (mg/L as F) (00950) Silica, dissolved (mg/L as SiO2) (00955) Sulfate, dissolved (mg/L as SO4) (00945) Nitrogen, ammonia, dissolved (mg/L as N) (00608) Nitrogen, nitrate, dissolved (mg/L as N) (00618) Nitrogen, nitrite plus nitrate, dissolved (mg/L as N) (00631) Nitrogen, nitrite, dissolved, (mg/L as N) (00613) 2S/11W-18L14A 09/06/94 1530 <0.2 106

— 0.2

— 224

— 0.67

— <0.020

(MLS20) 09/07/94 0915 <.2 133 3.6 .3

— 195

— 8.74

— 1.26

09/09/94 1030 .5 139 5.6 .5

— 136

— 4.84

— 2.45

09/12/94 0845 <.2 119 3.4 .3

— 134

— 5.67

— 1.98

09/16/94 0830 1.4 134

— .3

— 134

— 2.89

— <1.28

09/19/94 1425 <.2 124 1.6 .4

— 137

— 5.86

— .78

09/22/94 0915 <.2 130 .4 .5

— 135

— 4.31

— .3

2S/11W-18L14E 09/06/94 1325 .6 117

— .3

— 193

— 10.3

— .07

(MLS16)2S/11W-18L14F 09/07/94 1035 <.2 129 3.6 <.6

— 142

— 4.53

— 1.78

(MLS15) 09/09/94 1000 <.2 139 5.6 <.2

— 136

— 4.54

— 2.75

09/12/94 0850 <.2 112 2.8 .4

— 131

— 5.88

— 1.81

09/16/94 0900 .7 132

— .37

— 133

— 3.56

— .15

09/19/94 1430 <.2 119

— .5

— 137

— 6.64

— .03

09/21/94 1145 .11 130

— .6 22 130 2.9

— 4.8 <.010

09/22/94 0920 <.2 134

— .4

— 135

— 4.78

— <.020

2S/11W-18L14I 09/16/94 1000 .4 129

— .2

— 134

— 4.4

— .86

(MLS12) 09/19/94 1545 <.2 115 1 .4

— 134

— 6.5

— .53

2S/11W-18L14J 09/07/94 1215 .2 123 6.4 .5

— 147

— 3.86

— 2.37

(MLS11) 09/12/94 1040 .4 111 2.8 .5

— 134

— 5.49

— 1.82

2S/11W-18L14K 09/09/94 1230 <.2 131 5.2 .4

— 140

— 3.49

— 2.49

(MLS10)2S/11W-18L27 09/06/94 1440 .3 105

— .3

— 194

— .83

— <.020

(PR8 at 49 ft) 09/07/94 1150 <.2 107

— .2

— 199

— .84

— <.020

09/09/94 1330 <.2 106

— <.2

— 210

— .64

— <.020

09/12/94 1320 <.2 121 5.6 .2

— 164

— 3.1

— 1.47

Appendix 4B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, bromide–nitrogen[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less than value 

shown; —, no data; MLS, multilevel sampler]
Appendixes 229

09/16/94 1150 <0.2 124 — 0.3 — 146 — 5.12 — 2.5109/19/94 2005 <.2 130 0.4 .2 — 138 — 4.31 — 2.0409/22/94 1215 <.2 126 4 .3 — 134 — 4.27 — 1.82

2S/11W-18L28 09/06/94 1210 <.2 108 — .2 — 226 — .17 — <.020(PR9 at 25 ft) 09/07/94 0945 .5 127 5.2 .5 — 140 — 3.81 — 1.95

09/09/94 1045 <.2 140 6.8 .5 — 134 — 4.86 — 3.3709/12/94 1430 <.2 112 5.6 .3 — 130 — 5.59 — 2.5409/16/94 1325 <.2 134 — .5 — 134 — 3.29 — 2.5509/19/94 1815 .09 120 4 .7 22 130 2.5 6 8 209/22/94 1330 <.2 133 3.2 .4 — 135 — 4.34 — 1.68

2S/11W-18L29 09/06/94 1620 <.2 102 — .2 — 160 — 1.02 — <.020(PR10 at 60 ft) 09/07/94 1435 <.2 100 — .2 — 160 — 1.02 — <.020

09/09/94 1530 1.2 102 — .3 — 171 — 1.02 — <.02009/12/94 1000 <.2 98 — .2 — 168 — 1.43 — .0109/16/94 1055 <.2 108 — .3 — 189 — 1.33 — .3309/19/94 1415 <.2 111 .8 .2 — 199 — 2.44 — .509/22/94 0930 <.2 129 3 .3 — 168 — 3.98 — 1.72

2S/11W-18L30 09/06/94 1835 <.2 120 — .5 — 183 — 3.86 — <.02(PR11 at 36 ft) 09/07/94 1630 <.2 125 3.2 .4 — 168 — 6.09 — 1.22

09/09/94 1700 .3 137 9.6 .5 — 132 — 4.9 — 3.2109/12/94 1100 .1 120 4.6 .5 — 139 — 6.52 — 2.7709/16/94 0925 .4 134 — .4 — 137 — 3.05 — 2.5809/19/94 1600 .06 120 1 .7 22 130 1.7 6.1 7.9 1.809/22/94 1115 .2 132 2 .4 — 136 — 4.1 — .93

POND AT PICO 09/07/94 1515 <.2 149 4 .4 — 133 — 5.11 — 1.66(PR12) 09/09/94 1625 <.2 148 4.6 .3 — 138 — 6.62 — 1.81

09/12/94 1415 <.2 111 4.6 .4 — 133 — 6.19 — 1.9509/16/94 1030 <.2 125 — .4 — 137 — 4.39 — 2.3409/19/94 1845 .2 121 5.6 .3 — 138 — 7.07 — 2.64

Appendix 4B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, bromide–nitrogen—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L as Br)

(71870)

Chloride, 

dissolved 

(mg/L as Cl)

(00940)

Chlorine, 

total 

residual 

(mg/L)

(50060)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

(mg/L as N)

(00613)
230 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 09/22/94 1345 <0.2 129 6 0.5

— 136

— 5.8

— 2.43

09/23/94 1145 .04 130 7 .7 22 130 4.1 5.4 7.8 2.4

Appendix 4B. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, bromide–nitrogen—Continued

Station name

(Local identifier) Date Time

Bromide, 

dissolved 

(mg/L as Br)

(71870)

Chloride, 

dissolved 

(mg/L as Cl)

(00940)

Chlorine, 

total 

residual 

(mg/L)

(50060)

Fluoride, 

dissolved 

(mg/L as F)

(00950)

 Silica, 

dissolved 

(mg/L as 

SiO2)

(00955)

Sulfate, 

dissolved 

(mg/L as 

SO4)

(00945)

Nitrogen, 

ammonia, 

dissolved 

(mg/L as N)

(00608)

Nitrogen, 

nitrate, 

dissolved 

(mg/L as N)

(00618)

Nitrogen, 

nitrite plus 

nitrate, 

dissolved 

(mg/L as N)

(00631)

Nitrogen, 

nitrite, 

dissolved, 

(mg/L as N)

(00613)
Appendixes 231

Appendix 4C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, phosphorus–chromium—Continued

Station name

(Local identifier) Date Time

Phosphorus 

ortho-phosphate, 

dissolved 

(mg/L as P)

(00671)

 Barium,

dissolved 

(μg/L as Ba)

(01005)

 Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Boron, 

dissolved 

(μg/L as B)

(01020)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

 Chromium, 

dissolved 

(μg/L as Cr)

(01030)

2S/11W-18L14A 09/06/94 1530 0.5 — — — — —(MLS20) 09/07/94 0915 <.4 — — — — —

09/09/94 1030 .5 — — — — —09/12/94 0845 1.2 — — — — —09/16/94 0830 1.2 — — — — —09/19/94 1425 1.6 — — — — —09/22/94 0915 1.1 — — — — —

2S/11W-18L14E 09/06/94 1325 1.1 — — — — —(MLS16)2S/11W-18L14F 09/07/94 1035 .7 — — — — —(MLS15) 09/09/94 1000 1.3 — — — — —

09/12/94 0850 1.1 — — — — —09/16/94 0900 1.3 — — — — —09/19/94 1430 .9 — — — — —09/21/94 1145 1.9 170 <0.5 430 <1 <509/22/94 0920 1.5 — — — — —

2S/11W-18L14I 09/16/94 1000 1.8 — — — — —(MLS12) 09/19/94 1545 1.7 — — — — —2S/11W-18L14J 09/07/94 1215 .8 — — — — —(MLS11) 09/12/94 1040 1.7 — — — — —2S/11W-18L14K 09/09/94 1230 1.5 — — — — —(MLS10)2S/11W-18L27 09/06/94 1440 1 — — — — —(PR8 at 49 ft) 09/07/94 1150 .3 — — — — —

09/09/94 1330 1.3 — — — — —09/12/94 1320 .2 — — — — —09/16/94 1150 .4 — — — — —

Appendix 4C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, phosphorus–chromium[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; mg/L, milligrams per liter; μg/L, micrograms per liter; 

<, actual value less than value shown; —, no data; MLS, multilevel sampler]
232 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 09/19/94 2005 0.3

—

—

—

—

—

09/22/94 1215 <.4

—

—

—

—

—

2S/11W-18L28 09/06/94 1210 1.1

—

—

—

—

—

(PR9 at 25 ft) 09/07/94 0945 <.4

—

—

—

—

—

09/09/94 1045 <.4

—

—

—

—

—

09/12/94 1430 1.7

—

—

—

—

—

09/16/94 1325 1.1

—

—

—

—

—

09/19/94 1815 1.5 150 <0.5 430 <1 <509/22/94 1330 1.4

—

—

—

—

—

2S/11W-18L29 09/06/94 1620 <.4

—

—

—

—

—

(PR10 at 60 ft) 09/07/94 1435 <.4

—

—

—

—

—

09/09/94 1530 1.4

—

—

—

—

—

09/12/94 1000 <.4

—

—

—

—

—

09/16/94 1055 .6

—

—

—

—

—

09/19/94 1415 2.4

—

—

—

—

—

09/22/94 0930 .4

—

—

—

—

—

2S/11W-18L30 09/06/94 1835 <.4

—

—

—

—

—

(PR11 at 36 ft) 09/07/94 1630 .6

—

—

—

—

—

09/09/94 1700 1.9

—

—

—

—

—

09/12/94 1100 1.6

—

—

—

—

—

09/16/94 0925 3.3

—

—

—

—

—

09/19/94 1600 1.6 150 <.5 410 <1 <509/22/94 1115 1.2

—

—

—

—

—

POND AT PICO 09/07/94 1515 .8

—

—

—

—

—

(PR12) 09/09/94 1625 11.4

—

—

—

—

—

09/12/94 1415 1.5

—

—

—

—

—

09/16/94 1030 1.7

—

—

—

—

—

09/19/94 1845 1.7

—

—

—

—

—

09/22/94 1345

—

—

—

—

—

—

09/23/94 1145 2 43 <.5 450 <1 <5

Appendix 4C. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, phosphorus–chromium—Continued

Station name

(Local identifier) Date Time

Phosphorus 

ortho-phosphate, 

dissolved 

(mg/L as P)

(00671)

 Barium,

dissolved 

(μg/L as Ba)

(01005)

 Beryllium, 

dissolved 

(μg/L as Be)

(01010)

Boron, 

dissolved 

(μg/L as B)

(01020)

 Cadmium, 

dissolved 

(μg/L as Cd)

(01025)

 Chromium, 

dissolved 

(μg/L as Cr)

(01030)
Appendixes 233

Appendix 4D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, cobalt–manganese—Continued

Station name

(Local identifier) Date Time

 Cobalt, 

dissolved

(μg/L as Co)

(01035)

Copper, 

dissolved 

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

 Lithium, 

Dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)

2S/11W-18L14A 09/06/94 1530 — — — — — —(MLS20) 09/07/94 0915 — — — — — —

09/09/94 1030 — — — — — —09/12/94 0845 — — — — — —09/16/94 0830 — — — — — —09/19/94 1425 — — — — — —09/22/94 0915 — — — — — —

2S/11W-18L14E 09/06/94 1325 — — — — — —(MLS16)2S/11W-18L14F 09/07/94 1035 — — — — — —(MLS14) 09/09/94 1000 — — — — — —

09/12/94 0850 — — — — — —09/16/94 0900 — — — — — —09/19/94 1430 — — — — — —09/21/94 1145 <3 10 17 <10 19 8709/22/94 0920 — — — — — —

2S/11W-18L14I 09/16/94 1000 — — — — — —(MLS12) 09/19/94 1545 — — — — — —2S/11W-18L14J 09/07/94 1215 — — — — — —(MLS11) 09/12/94 1040 — — — — — —2S/11W-18L14K 09/09/94 1230 — — — — — —(MLS10)2S/11W-18L27 09/06/94 1440 — — — — — —(PR8 at 49 ft) 09/07/94 1150 — — — — — —

09/09/94 1330 — — — — — —09/12/94 1320 — — — — — —09/16/94 1150 — — — — — —09/19/94 2005 — — — — — —

Appendix 4D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, cobalt–manganese[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value 

shown; —, no data; MLS, multilevel sampler]
234 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California 09/22/94 1215

—

—

—

—

—

—

2S/11W-18L28 09/06/94 1210

—

—

—

—

—

—

(PR9 at 25 ft) 09/07/94 0945

—

—

—

—

—

—

09/09/94 1045

—

—

—

—

—

—

09/12/94 1430

—

—

—

—

—

—

09/16/94 1325

—

—

—

—

—

—

09/19/94 1815 <3 <10 9 30 15 11009/22/94 1330

—

—

—

—

—

—

2S/11W-18L29 09/06/94 1620

—

—

—

—

—

—

(PR10 at 60 ft) 09/07/94 1435

—

—

—

—

—

—

09/09/94 1530

—

—

—

—

—

—

09/12/94 1000

—

—

—

—

—

—

09/16/94 1055

—

—

—

—

—

—

09/19/94 1415

—

—

—

—

—

—

09/22/94 0930

—

—

—

—

—

—

2S/11W-18L30 09/06/94 1835

—

—

—

—

—

—

(PR11 at 36 ft) 09/07/94 1630

—

—

—

—

—

—

09/09/94 1700

—

—

—

—

—

—

09/12/94 1100

—

—

—

—

—

—

09/16/94 0925

—

—

—

—

—

—

09/19/94 1600 <3 10 10 20 13 9609/22/94 1115

—

—

—

—

—

—

POND AT PICO 09/07/94 1515

—

—

—

—

—

—

(PR12) 09/09/94 1625

—

—

—

—

—

—

09/12/94 1415

—

—

—

—

—

—

09/16/94 1030

—

—

—

—

—

—

09/19/94 1845

—

—

—

—

—

—

09/22/94 1345

—

—

—

—

—

—

09/23/94 1145 <3 <10 35 40 16 16

Appendix 4D. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, cobalt–manganese—Continued

Station name

(Local identifier) Date Time

 Cobalt, 

dissolved

(μg/L as Co)

(01035)

Copper, 

dissolved 

(μg/L as Cu)

(01040)

Iron, 

dissolved

(μg/L as Fe)

(01046)

 Lead, 

dissolved 

(μg/L as Pb)

(01049)

 Lithium, 

Dissolved 

(μg/L as Li)

(01130)

 Manganese, 

dissolved 

(μg/L as Mn)

(01056)
Appendixes 235

Appendix 4E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

Strontium, 

dissolved

(μg/L as Sr)

(01080)

 Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)

2S/11W-18L14 A 09/06/94 1530 — — — — — —(MLS20) 09/07/94 0915 — — — — — —

09/09/94 1030 — — — — — —09/12/94 0845 — — — — — —09/16/94 0830 — — — — — —09/19/94 1425 — — — — — —09/22/94 0915 — — — — — —

2S/11W-18L14E 09/06/94 1325 — — — — — —(MLS16)2S/11W-18L14F 09/07/94 1035 — — — — — —(MLS15) 09/09/94 1000 — — — — — —

09/12/94 0850 — — — — — —09/16/94 0900 — — — — — —09/19/94 1430 — — — — — —09/21/94 1145 30 <10 2 500 12 2809/22/94 0920 — — — — — —

2S/11W-18L14I 09/16/94 1000 — — — — — —(MLS12) 09/19/94 1545 — — — — — —2S/11W-18L14J 09/07/94 1215 — — — — — —(MLS11) 09/12/94 1040 — — — — — —2S/11W-18L14K 09/09/94 1230 — — — — — —(MLS10)2S/11W-18L27 09/06/94 1440 — — — — — —(PR8 at 49 ft) 09/07/94 1150 — — — — — —

09/09/94 1330 — — — — — —09/12/94 1320 — — — — — —09/16/94 1150 — — — — — —09/19/94 2005 — — — — — —09/22/94 1215 — — — — — —

2S/11W-18L28 09/06/94 1210 — — — — — —

Appendix 4E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, molybdenum–zinc[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, no data; MLS, multilevel sampler]
236 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, Californi (PR9 at 25 ft) 09/07/94 0945

—

—

—

—

—

—

09/09/94 1045

—

—

—

—

—

—

09/12/94 1430

—

—

—

—

—

—

09/16/94 1325

—

—

—

—

—

—

09/19/94 1815 50 20 1 560 16 1409/22/94 1330

—

—

—

—

—

—

2S/11W-18L29 09/06/94 1620

—

—

—

—

—

—

(PR10 at 60 ft) 09/07/94 1435

—

—

—

—

—

—

09/09/94 1530

—

—

—

—

—

—

09/12/94 1000

—

—

—

—

—

—

09/16/94 1055

—

—

—

—

—

—

09/19/94 1415

—

—

—

—

—

—

09/22/94 0930

—

—

—

—

—

—

2S/11W-18L30 09/06/94 1835

—

—

—

—

—

—

(PR11 at 36 ft) 09/07/94 1630

—

—

—

—

—

—

09/09/94 1700

—

—

—

—

—

—

09/12/94 1100

—

—

—

—

—

—

09/16/94 0925

—

—

—

—

—

—

09/19/94 1600 60 10 2 620 17 1009/22/94 1115

—

—

—

—

—

—

POND AT PICO 09/07/94 1515

—

—

—

—

—

—

(PR12) 09/09/94 1625

—

—

—

—

—

—

09/12/94 1415

—

—

—

—

—

—

09/16/94 1030

—

—

—

—

—

—

09/19/94 1845

—

—

—

—

—

—

09/22/94 1345

—

—

—

—

—

—

09/23/94 1145 30 10 3 490 <6 51

Appendix 4E. Water-quality data for samples collected near the research basin, Montebello Forebay, Los Angeles County, California, during September 1994, molybdenum–zinc—Continued

Station name

(Local identifier) Date Time

Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

 Nickel, 

dissolved 

(μg/L as Ni)

(01065)

 Silver, 

dissolved 

(μg/L as Ag)

(01075)

Strontium, 

dissolved

(μg/L as Sr)

(01080)

 Vanadium, 

dissolved 

(μg/L as V)

(01085)

Zinc,

dissolved 

(μg/L as Zn)

(01090)
Appendixes 237

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L10LYS 08-10-93 2130 120 68 <1 — — —

(CR-RED at 50 ft) 08-11-93 1900 115 72 <1 0.1 <0.1 <3

08-12-93 1655 127 76 <1 <.1 <.1 <3

08-13-93 1020 129 76 <1 <.1 <.1 <3

08-16-93 1050 135 77 <1 <.1 <.1 <3

08-23-93 1054 120 67 <1 <.1 <.1 <3

08-24-93 1800 118 64 <1 .08 <.01 <3

08-28-93 1900 117 62 <1 .26 <.01 <3

08-29-93 1800 125 65 <1 .34 <.01 <3

08-30-93 1118 134 68 <1 .25 <.01 <3

2S/11W-18L11LYS 08-10-93 2135 120 64 <1 .2 <.1 <3

(CR-ORG at 25 ft) 08-11-93 1905 121 66 <1 .2 <.1 <3

08-12-93 1700 122 68 <1 .2 <.1 <3

08-13-93 1025 123 69 <1 .1 <.1 <3

08-16-93 1055 124 69 <1 .1 <.1 <3

08-23-93 1109 — 65 <1 .15 <.01 <3

08-24-93 1800 122 68 <1 .06 <.01 <3

08-28-93 1900 118 64 <1 .05 <.01 <3

08-29-93 1800 120 65 <1 .05 <.01 <3

08-30-93 1115 121 64 <1 .08 <.01 <3

2S/11W-18L13LYS 08-10-93 2140 112 134 <1 <.1 .1 <3

(CR-BLU at 13.5 ft) 08-11-93 1910 109 135 <1 <.1 .1 <3

08-12-93 1710 93 138 <1 <.1 <.1 <3

08-13-93 1030 105 137 <1 <.1 <.1 <3

08-16-93 1100 97 137 <1 <.1 <.1 <3

08-23-93 1112 80 131 <1 <.01 <.01 <3

08-24-93 1800 102 131 <1 <.01 <.01 <3

08-28-93 1900 100 123 <1 <.01 <.01 <3

08-29-93 1800 110 124 <1 <.01 <.01 <3

08-30-93 1120 104 122 <1 <.01 <.01 <3

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993

[See table 1 for explanation of local identifier below station name; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less 

than value shown; —, no data; CR, ceramic-cup lysimeter; SS, stainless steel lysimeter; MLS, multilevel sampler; samples differing by one minute represent 

duplicate analyses]
238 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14A 08-10-93 2110 117 82 <1 0.6 <0.1 <3

(MLS20) 08-11-93 2000 119 73 <1 .7 <.1 <3

2001 119 73 <1 .7 <.1 <3

08-12-93 2000 118 77 <1 .8 <.1 <3

08-13-93 1920 120 83 <1 1.2 <.1 <3

08-16-93 1855 124 93 <1 1.3 <.1 <3

08-23-93 1900 127 87 <1 1.3 .02 <3

08-24-93 1700 110 74 <1 .88 .02 <3

08-28-93 1730 113 75 <1 .7 <.01 <3

08-29-93 1635 118 72 <1 .4 .01 <3

08-30-93 1730 123 69 <1 .26 <.01 <3

2S/11W-18L14B 08-10-93 2040 125 103 <1 1.3 <.1 <3

(MLS19) 08-11-93 1930 107 68 <1 .5 <.1 <3

08-12-93 1920 119 111 <1 1.3 <.1 <3

08-13-93 1845 125 110 <1 .9 <.1 <3

08-16-93 1818 135 105 <1 .1 <.1 <3

08-23-93 1830 130 98 <1 .62 <.01 <3

08-24-93 1650 124 95 <1 .61 <.01 <3

08-28-93 1715 114 94 <1 .44 <.01 <3

1716 114 92 <1 .46 <.01 <3

08-29-93 1620 119 92 <1 .39 .01 <3

1621 120 92 <1 .39 .01 <3

08-30-93 1715 107 97 <1 .33 <.01 <3

2S/11W-18L14C 08-10-93 2005 130 110 <1 2.7 <.1 <3

(MLS18) 08-11-93 1900 126 109 <1 1.9 <.1 <3

08-12-93 1845 118 111 <1 .8 <.1 <3

08-13-93 1800 121 107 <1 .3 <.1 <3

08-16-93 1745 121 101 <1 <.1 <.1 <3

08-23-93 1815 127 95 <1 .06 <.01 <3

08-24-93 1615 111 91 <1 .09 <.01 <3

08-28-93 1655 122 99 <1 .11 <.01 <3

08-29-93 1600 118 91 <1 .09 <.01 <3

08-30-93 1630 117 95 <1 .12 <.01 <3

1631 112 93 <1 .11 <.01 <3
Appendixes 239

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14D 08-10-93 1930 131 111 <1 1.3 <0.1 <3

(MLS17) 08-11-93 1830 121 107 <1 .6 <.1 <3

08-12-93 1800 112 115 <1 .2 <.1 <3

08-13-93 1745 118 114 <1 <.1 <.1 <3

08-16-93 1705 140 119 <1 <.1 <.1 <3

08-23-93 1800 135 107 <1 .04 <.01 <3

08-24-93 1550 144 111 <1 .08 <.01 <3

08-28-93 1640 124 107 <1 .11 <.01 <3

08-29-93 1540 123 103 <1 .07 <.01 <3

08-30-93 1600 111 100 <1 .09 <.01 <3

2S/11W-18L14E 08-10-93 1915 131 92 <1 1.4 <.1 <3

(MLS16) 08-11-93 1745 130 94 <1 .7 <.1 <3

08-12-93 1700 124 99 <1 .2 <.1 <3

08-13-93 1720 125 98 <1 <.1 <.1 <3

08-16-93 1620 140 108 <1 <.1 <.1 <3

08-23-93 1710 146 104 <1 .06 <.01 <3

1711 143 102 <1 .06 <.01 <3

08-24-93 1525 145 103 <1 .09 <.01 <3

08-28-93 1620 126 98 <1 .09 <.01 <3

08-29-93 1510 122 93 <1 .07 <.01 <3

08-30-93 1540 118 93 <1 .09 <.01 <3

2S/11W-18L14F 08-10-93 1755 136 85 <1 2.5 <.1 <3

(MLS15) 08-11-93 1700 137 90 <1 1.3 <.1 <3

08-12-93 1620 141 95 <1 <.1 <.1 <3

08-13-93 1700 134 92 <1 <.1 <.1 <3

08-16-93 1530 159 102 <1 <.1 <.1 <3

08-23-93 1700 157 97 <1 .07 <.01 <3

08-24-93 1450 171 101 <1 .12 <.01 <3

08-28-93 1600 133 92 <1 .09 <.01 <3

08-29-93 1450 146 96 <1 .09 <.01 <3

08-30-93 1440 137 92 <1 .11 <.01 <3
240 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14G 08-10-93 1710 140 91 <1 0.7 <0.1 <3

(MLS14) 08-11-93 1610 138 94 <1 <.1 <.1 <3

08-12-93 1500 123 101 <1 <.1 <.1 <3

08-13-93 1645 153 105 <1 <.1 <.1 <3

08-16-93 1550 156 119 <1 <.1 <.1 <3

08-23-93 1630 159 98 <1 .79 <.01 <3

08-24-93 1430 182 100 <1 .12 <.01 <3

08-28-93 1500 154 99 <1 .1 <.01 <3

08-29-93 1250 159 97 <1 .1 <.01 <3

08-30-93 1430 160 103 <1 .12 <.01 <3

2S/11W-18L14H 08-10-93 1625 152 101 <1 <.1 <.1 <3

(MLS13) 08-11-93 1545 157 104 <1 <.1 <.1 <3

08-12-93 1445 167 108 <1 <.1 <.1 <3

08-13-93 1620 151 111 <1 <.1 <.1 <3

08-16-93 1430 140 125 <1 .2 <.1 <3

08-23-93 1600 157 101 <1 .07 <.01 <3

08-24-93 1315 190 105 <1 .1 <.01 <3

08-28-93 1515 162 99 <1 .09 <.01 <3

08-29-93 1235 166 102 <1 .1 <.01 <3

08-30-93 1310 161 99 <1 .11 <.01 <3

2S/11W-18L14I 08-10-93 1525 132 103 <1 <.1 <.1 <3

(MLS12) 08-11-93 1520 146 105 <1 <.1 <.1 <3

08-12-93 1315 145 98 <1 <.1 <.1 <3

08-13-93 1530 132 118 <1 <.1 <.1 <3

08-16-93 1250 149 132 <1 <.1 <.1 <3

08-23-93 1520 169 105 <1 .07 <.01 <3

08-24-93 1220 148 108 <1 .09 <.01 <3

1221 149 101 <1 .1 <.01 <3

1222 170 109 <1 .1 <.01 <3

1223 152 105 <1 .07 <.01 <3

08-28-93 1335 157 101 <1 .1 <.01 <3

08-29-93 1220 170 108 <1 .11 <.01 <3

08-30-93 1230 153 100 <1 .11 <.01 <3
Appendixes 241

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14J 08-10-93 1500 169 107 <1———

(MLS11) 08-11-93 1240 167 104 <1 <0.1 <0.1 <3

08-12-93 1250 153 114 <1 <.1 <.1 <3

08-13-93 1500 114 133 <1 .3 <.1 <3

08-16-93 1245 150 136 <1 <.1 <.1 8.2

08-23-93 1500 167 107 <1 <.1 <.1 <3

08-24-93 1200 163 110 <1 .1 <.01 <3

08-28-93 1315 160 102 <1 .12 <.01 <3

08-29-93 1200 167 105 <1 .12 <.01 <3

08-30-93 1215 149 97 <1 .11 <.01 <3

2S/11W-18L14K 08-10-93 1415 172 109 <1 <.1 <.1 <3

(MLS10) 08-11-93 1210 165 105 <1 <.1 <.1 <3

08-12-93 1220 120 125 <1 <.1 <.1 <3

08-13-93 1300 108 135 <1 <.1 <.1 <3

08-16-93 1200 149 135 <1 <.1 <.1 <3

08-23-93 1230 150 115 <1 .3 <.01 <3

08-24-93 1105 144 110 <1 .29 <.01 <3

1106 156 116 <1 .3 <.01 <3

08-28-93 1250 160 104 <1 .73 <.01 <3

1251 162 107 <1 .74 <.01 <3

08-29-93 1125 163 105 <1 .54 <.01 <3

08-30-93 1150 166 106 <1 .39 <.01 <3

2S/11W-18L14L 08-10-93 1345 172 107 <1 .9 <.1 <3

(MLS9) 1346 172 107 <1 .9 <.1 <3

08-11-93 1115 165 105 <1 <.1 <.1 <3

08-12-93 1130 123 126 <1 2.2 <.1 <3

08-13-93 1230 133 135 <1 <.1 <.1 <3

08-16-93 1130 148 135 <1 <.1 <.1 <3

08-23-93 1210 129 124 <1 .2 <.01 <3

08-24-93 1045 121 116 <1 .2 <.01 <3

08-28-93 1230 139 113 <1 1.1 <.01 <3

08-29-93 1105 160 109 <1 .95 <.01 <3

08-30-93 1130 143 105 <1 .9 <.01 <3

1131 145 105 <1 .9 <.01 <3

1132 152 102 <1 .91 <.01 <3

1133 134 100 <1 .87 <.01 <3
242 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14M 08-10-93 1230 130 118 <1 0.2 <0.1 <3

(MLS8) 08-11-93 1030 126 118 <1 <.1 <.1 <3

08-12-93 1100 105 125 <1 .4 <.1 <3

08-13-93 1150 102 127 <1 <.1 <.1 <3

08-16-93 1100 129 130 <1 <.1 <.1 <3

08-23-93 1145 131 120 <1 .01 <.01 <3

08-24-93 1020 133 122 <1 .07 <.01 <3

08-28-93 1120 121 118 <1 .12 <.01 <3

08-29-93 1050 118 113 <1 .05 <.01 <3

1051 120 116 <1 .05 <.01 <3

1052 125 117 <1 .06 <.01 <3

1053 119 118 <1 .05 <.01 <3

08-30-93 1050 119 107 <1 .12 <.01 <3

2S/11W-18L14N 08-10-93 1115 109 137 <1 <.1 <.1 <3

(MLS7) 08-11-93 1000 101 136 <1 <.1 <.1 <3

08-12-93 1030 76 143 <1 <.1 <.1 <3

08-13-93 1040 93 135 <1 <.1 <.1 3.1

08-16-93 1015 134 128 <1 <.1 <.1 3.5

08-23-93 1100 121 125 <1 <.01 <.01 <3

08-24-93 0930 113 124 <1 .01 <.01 <3

08-28-93 1050 92 124 <1 <.01 <.01 <3

08-29-93 1030 99 126 <1 <.01 <.01 <3

08-30-93 1030 88 125 <1 <.01 <.01 <3

2S/11W-18L14O 08-10-93 1010 110 135 <1 <.1 <.1 <3

(MLS6) 08-11-93 0930 93 134 <1 <.1 <.1 <3

08-12-93 0930 70 138 <1 <.1 <.1 <3

08-13-93 1015 90 131 <1 <.1 <.1 <3

08-16-93 1000 116 123 <1 <.1 <.1 <3

08-23-93 1050 132 131 <1 <.01 <.01 <3

1051 131 131 <1 <.01 <.01 <3

1052 128 129 <1 .03 <.01 <3

1053 133 129 <1 .03 <.01 <3

08-24-93 0850 114 121 <1 <.01 <.01 <3

08-28-93 1020 100 121 <1 .04 <.01 <3

08-29-93 1015 102 122 <1 <.01 <.01 <3

08-30-93 1000 97 118 <1 .02 <.01 <3
Appendixes 243

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14P 08-10-93 0846 92 128 <1 <0.1 <0.1 <3

(MLS5) 08-11-93 0900 77 132 <1 <.1 <.1 3.6

08-12-93 0900 59 138 <1 <.1 <.1 <3

08-13-93 0845 50 136 <1 <.1 <.1 <3

08-16-93 0900 109 136 <1 <.1 <.1 <3

08-23-93 0945 115 132 <1 <.01 <.01 <3

08-24-93 0830 96 119 <1 <.01 <.01 <3

08-28-93 0930 91 125 <1 .01 <.01 <3

08-29-93 0930 77 121 <1 <.01 <.01 <3

08-30-93 0920 73 119 <1 <.01 <.01 <3

2S/11W-18L14Q 08-10-93 0845 75 128 <1 <.1 <.1 <3

(MLS4) 08-11-93 0845 44 126 <1 <.1 <.1 <3

08-12-93 0845 59 139 <1 <.1 <.1 3.5

08-13-93 0810 105 132 <1 <.1 <.1 <3

08-16-93 0845 104 123 <1 <.1 <.1 <3

08-23-93 0920 105 118 <1 <.01 <.01 <3

08-24-93 0815 105 120 <1 <.01 <.01 <3

08-28-93 0930 93 122 <1 <.01 <.01 <3

08-29-93 0910 80 122 <1 <.01 <.01 <3

08-30-93 0820 83 125 <1 <.01 <.01 <3

2S/11W18L15LYS08-10-93 1955 83 39 <1 .5 .1 <3

(SS-RED at 49 ft) 08-11-93 1815 88 42 <1 .5 .1 <3

08-12-93 1550 91 46 <1 .4 <.1 <3

08-13-93 0905 89 47 <1 .3 <.1 <3

08-16-93 0750 96 52 <1 .1 <.1 <3

08-23-93 0850 94 54 <1 .02 <.01 <3

08-24-93 1800 87 48 <1 .15 .02 <3

08-28-93 1900 92 51 <1 .03 <.01 <3

08-29-93 1800 93 51 <1 .05 <.01 <3

08-30-93 0900 101 54 <1 .06 <.01 <3

2S/11W18L16LYS08-10-93 2015 82 54 <1 <.1 .1 <3

(SS-ORG at 25 ft) 08-11-93 1835 108 63 <1 <.1 <.1 <3

08-12-93 1555 107 64 <1 <.1 <.1 <3

08-13-93 0915 111 64 <1 <.1 <.1 <3

08-16-93 0755 109 64 <1 <.1 <.1 <3

08-23-93 0851 106 59 <1 .04 <.01 <3

08-24-93 1800 93 53 <1 .01 <.01 <3

08-28-93 1900 101 57 <1 .04 <.01 <3

08-29-93 1800 90 51 <1 .02 <.01 <3

08-30-93 0900 100 54 <1 .03 <.01 <3
244 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L27 08-10-93 1835 112 60 <1 0.8 <0.1 <3

(PR8 at 49 ft) 08-11-93 1730 113 61 <1 .6 <.1 <3

08-12-93 1730 119 63 <1 .6 <.1 <3

08-13-93 1820 120 64 <1 .6 <.1 <3

08-16-93 1650 121 63 <1 .6 <.1 <3

08-23-93 1530 106 57 <1 .58 <.01 <3

08-24-93 1305 106 58 <1 .59 <.01 <3

08-28-93 1350 103 58 <1 .62 <.01 <3

08-29-93 1305 109 60 <1 .58 <.01 <3

08-30-93 1450 105 58 <1 .6 <.01 <3

2S/11W-18L28 08-10-93 2145 114 62 <1 .9 <.1 <3

(PR9 at 25 ft) 08-11-93 1500 116 64 <1 .8 <.1 <3

08-12-93 1600 115 67 <1 .8 <.1 <3

08-13-93 1600 117 67 <1 .7 <.1 <3

08-16-93 1910 119 73 <1 .6 <.1 <3

08-23-93 1730 119 72 <1 .45 <.01 <3

08-24-93 1510 121 76 <1 .48 <.01 <3

08-28-93 1530 123 73 <1 .43 <.01 <3

1531 123 73 <1 .43 <.01 <3

08-29-93 1535 116 67 <1 .38 <.01 <3

08-30-93 1620 123 69 <1 .41 <.01 <3

2S/11W-18L29 08-10-93 1100 135 82 <1 .2 <.1 <3

(PR10 at 60 ft) 08-11-93 1045 95 50 <1 .3 <.1 <3

08-12-93 0945 98 53 <1 .3 <.1 <3

08-13-93 1120 108 58 <1 .3 <.1 <3

08-16-93 1035 111 59 <1 .3 <.1 <3

1036 108 59 <1 .3 <.1 <3

1037 118 63 <1 .4 <.1 <3

1038 111 59 <1 .3 <.1 <3

08-23-93 1250 108 57 <1 .4 <.01 <3

08-24-93 0720 113 60 <1 .4 <.01 <3

08-28-93 1000 117 62 <1 .29 <.01 <3

08-29-93 1140 114 60 <1 .25 <.01 <3

08-30-93 1250 112 59 <1 .24 <.01 <3
Appendixes 245

Appendix 5. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during August 1993—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L30 08-10-93 1550 112 54 <1 0.3 <0.1 <3

(PR11 at 36 ft) 08-11-93 1300 133 80 <1 .3 <.1 <3

08-12-93 1200 112 73 <1 .3 <.1 <3

08-13-93 1330 129 77 <1 .3 <.1 <3

08-16-93 1450 121 78 <1 2.2 <.1 <3

08-23-93 1015 112 73 <1 1.5 <.01 <3

08-24-93 1130 112 75 <1 1.2 <.01 <3

08-28-93 1215 122 80 <1 .55 <.01 <3

08-29-93 0955 115 77 <1 .38 <.01 <3

08-30-93 1100 118 79 <1 .36 <.01 <3

08-10-93 2200 145 144 <1 <.1 <.1 <3

08-11-93 2100 144 133 <1 4.3 1.3 <3

08-12-93 2030 145 136 <1 4 1.7 <3

2031 145 136 <1 4.1 1.5 <3

2032 145 137 <1 4 1.7 <3

2033 148 135 <1 4.1 1.5 4

POND AT PICO 08-13-93 0910 145 136 <1 4.1 1.5 <3

(PR12) 08-16-93 1940 140 138 <1 4.1 2.6 <3

08-23-93 1920 127 123 <1 4.5 .29 <3

08-23-93 1930 118 119 <1 4.7 .25 <3

08-23-93 1950 126 113 <1 4.4 .22 <3

08-23-93 2030 136 122 <1 4.4 .23 <3

08-24-93 1720 124 126 <1 4.4 .23 <3

08-28-93 1745 126 126 <1 2.9 .28 <3

08-29-93 1700 116 114 <1 2.2 .26 <3

08-30-93 1745 120 119 <1 2.1 .25 <3

SEWAGE 08-10-93 2245 148 120 <1 5.8 1.6 <3

EFFLUENT 08-11-93 2045 140 124 <1 4 1.6 3

(PR13) 08-12-93 1950 132 134 <1 3.7 1.9 3

1951 132 135 <1 3.7 1.9 <3

08-13-93 1900 135 139 <1 4.5 2.1 <3

08-16-93 2000 130 135 <1 3.1 1.8 4

08-23-93 2010 120 108 <1 3 1.4 <3

08-24-93 1750 114 127 <1 3.1 1.6 <3

08-28-93 1805 119 132 <1 1.8 1.8 <3

08-29-93 1720 121 135 <1 4.3 1.5 —

08-30-93 1810 109 126 <1 1.9 1.5 <3
246 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

See footnote at end of table.

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14A 04-04-94 1940 158 102 <0.2 0.85 <0.01 <0.2

(MLS20) 04-05-94 1205 162 104 <.2 .97 <.01 <.2

04-05-94 1800 158 101 <.2 .94 <.01 .5

04-06-94 1400 157 99 <.2 2.06 .03 <.2

04-07-94 0900 157 119 <.2 4.84 .55 <.2

04-08-94 0825 154 127 <.2 5.83 .54 <.2

04-21-94 0915 147 129 <.2 3.06 1.20 <.2

09161 144 129 <.2 3.03 1.20 .4

06-01-94 1455 152 108 .2 1.34 .03 <.2

2S/11W-18L14C 04-07-94 0915 155 130 <.2 7.26 .63 .3

(MLS18) 04-08-94 0830 163 133 <.2 7.16 .65 .6

2S/11W-18L14F 04-04-94 1930 162 112 .3 1.27 .04 .2

(MLS15) 19311 158 111 .2 1.26 .04 .2

04-05-94 1145 172 118 .2 1.48 .03 <.2

04-05-94 1750 160 104 .3 1.70 <.01 .2

04-06-94 1350 154 135 .2 7.38 1.07 <.2

04-07-94 0945 150 133 <.2 7.08 1.04 <.2

04-08-94 0845 208 133 .3 9.48 .06 <.2

04-21-94 0945 144 129 <.2 2.43 <.013 .5

06-01-94 1435 143 121 .3 3.21 <.01 .5

2S/11W-18L14K 04-04-94 1855 154 93 <.2 2.27 <.01 .2

(MLS10) 04-05-94 1123 154 92 .8 2.40 <.01 <.2

04-05-94 1740 155 90 <.2 2.87 <.01 <.2

17411 156 91 <.2 2.90 <.01 .2

04-06-94 1145 155 132 <.2 8.55 .14 .2

04-07-94 1000 153 136 .2 7.73 .34 .5

04-08-94 0910 149 136 .3 7.22 .67 1.0

04-21-94 1000 144 128 .5 3.03 .01 1.0

06-01-94 1350 162 112 .3 .70 <.01 .4

2S/11W-18L14L 04-04-94 1835 152 91 <.2 2.47 <.01 .4

(MLS9) 04-05-94 1100 153 91 <.2 2.49 <.01 .3

04-05-94 1645 155 88 .2 3.05 <.01 <.2

04-06-94 1125 158 131 .9 8.41 .26 .5

04-07-94 1018 151 138 <.2 7.28 .78 .6

04-08-94 0945 146 136 .4 6.17 1.48 1.1

04-21-94 1020 141 127 <.2 3.74 <.01 1.1

06-01-94 1315 167 112 .3 .54 <.01 .6

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994

[See table 1 for explanation of local identifier below station name; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less 

than value shown; —, no data; MLS, multilevel sampler; samples differing by one minute represent duplicate analyses]
Appendixes 247

See footnote at end of table.

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14L 04-04-94 1835 152 91 <0.2 2.47 <0.01 0.4

(MLS9) 04-05-94 1100 153 91 <.2 2.49 <.01 .3

04-05-94 1645 155 88 .2 3.05 <.01 <.2

04-06-94 1125 158 131 .9 8.41 .26 .5

04-07-94 1018 151 138 <.2 7.28 .78 .6

04-08-94 0945 146 136 .4 6.17 1.48 1.1

04-21-94 1020 141 127 <.2 3.74 <.01 1.1

06-01-94 1315 167 112 .3 .54 <.01 .6

2S/11W-18L14M 04-04-94 1750 162 99 <.2 1.69 .03 .2

(MLS8) 04-05-94 1046 169 96 <.2 2.10 .03 <.2

04-05-94 1635 168 94 <.2 2.41 .02 <.2

04-06-94 1045 158 124 <.2 6.45 .44 <.2

04-07-94 1040 156 134 <.2 7.38 .46 .5

04-08-94 0930 199 135 .3 8.37 .39 <.2

09311 199 135 <.2 8.29 .39 <.2

04-21-94 1040 146 128 <.2 2.17 .04 .9

06-01-94 1210 149 116 .3 1.02 .02 .7

12111 150 117 .2 1.13 .02 .6

2S/11W-18L14N 04-04-94 1730 181 86 <.2 2.73 .09 <.2

(MLS7) 04-05-94 1010 163 91 <.2 2.71 .02 .4

04-05-94 1540 162 91 .3 2.70 <.01 .4

04-06-94 1000 168 121 <.2 7.10 .50 .6

04-07-94 1100 151 134 <.2 7.64 .51 .7

04-08-94 0950 172 135 <.2 7.73 .55 .8

04-21-94 1050 143 128 <.2 2.69 .27 1.2

06-01-94 1100 148 115 .3 .57 <.01 .9

2S/11W-18L14O 04-04-94 1715 165 86 <.2 2.93 .03 .4

(MLS6) 04-05-94 0950 166 92 <.2 2.57 .03 .6

09511 164 90 <.2 2.56 .03 .4

04-05-94 1532 177 90 .2 3.22 <.01 .4

15331 176 90 <.2 3.20 <.01 .6

04-06-94 0950 162 126 1.6 7.52 .58 <.2

04-07-94 1120 153 136 <.2 7.69 .56 .6

04-08-94 1045 169 136 <.2 7.40 .77 .5

04-21-94 1105 146 130 <.2 2.48 .12 .3

06-01-94 1040 139 120 .6 .81 .02 .9
248 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

See footnote at end of table.

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14P 04-04-94 1630 167 95 0.3 2.08 0.04 0.2

(MLS5) 04-05-94 0900 162 96 <.2 2.15 .03 .5

04-05-94 1505 191 90 <.2 3.22 <.01 .2

04-06-94 0818 175 119 <.2 7.26 .38 1.0

08191 173 120 <.2 7.26 .38 .6

04-07-94 1130 160 141 <.2 7.60 .88 .6

04-08-94 1055 178 136 <.2 7.52 .82 .5

10561 177 136 .2 7.52 .82 .8

04-21-94 1135 146 128 <.2 2.36 .11 1.1

11361 145 128 <.2 2.36 .11 1.3

06-01-94 0935 137 121 .4 .76 .03 1.1

2S/11W-18L14Q 04-04-94 1605 256 76 .2 5.75 <.01 .9

(MLS4) 04-05-94 0830 308 74 .7 7.00 <.01 .4

04-05-94 1450 339 88 .4 7.23 .34 .8

04-06-94 0820 166 127 <.2 7.76 1.08 .6

04-07-94 1144 153 135 <.2 6.71 1.25 .6

04-08-94 1125 169 137 <.2 7.43 .84 .8

04-21-94 1145 149 128 .2 2.02 .23 .8

06-01-94 0915 95 142 .5 .24 <.012 1.8

2S/11W-18L27 04-04-94 1905 151 99 <.2 1.44 <.01 <.2

(PR8 at 49 ft) 19061 152 102 <.2 1.48 <.01 <.2

19071 153 100 <.2 1.47 <.01 .4

04-05-94 1805 156 107 <.2 1.40 <.01 <.2

04-06-94 1205 159 109 .2 2.37 .11 <.2

12061 160 108 .2 2.36 .11 <.2

04-07-94 1425 149 98 <.2 1.49 <.01 <.2

04-08-94 1040 151 102 <.2 1.82 <.01 <.2

04-21-94 1740 153 100 .3 2.21 .02 <.2

17411 153 101 <.2 2.23 .02 <.2

17421 154 101 <.2 2.20 .02 <.2

06-01-94 1330 147 95 .2 1.32 <.01 <.2

1331 147 95 .5 1.31 <.014 .2

1332 148 96 .4 1.32 <.013 <.2
Appendixes 249

See footnote at end of table.

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L28 04-04-94 1720 158 107 <0.2 1.27 <0.01 <0.2

(PR9 at 25 ft) 17211 157 107 <.2 1.27 <.01 <.2

04-05-94 1700 149 98 .2 1.43 <.01 <.2

17011 150 99 .7 1.44 <.01 <.2

17021 151 100 .3 1.45 <.01 <.2

04-06-94 1030 151 99 <.2 1.50 <.01 <.2

04-07-94 1200 156 123 <.2 5.80 .95 <.2

04-08-94 1000 152 130 <.2 6.14 1.41 <.2

04-21-94 1625 140 123 <.2 6.53 1.79 <.2

06-01-94 1515 142 123 <.2 4.78 1.21 <.2

2S/11W-18L29 04-04-94 2000 158 109 .3 1.28 <.01 .4

(PR10 at 60 ft) 04-05-94 1405 157 109 .4 1.27 <.01 <.2

04-06-94 1550 156 109 <.2 1.29 <.01 <.2

04-07-94 1030 155 108 <.2 1.32 <.01 <.2

10311 157 109 <.2 1.34 <.01 <.2

04-08-94 1200 157 109 <.2 1.53 <.011 <.2

04-21-94 1445 — 103 — 1.64 <.01 —

06-01-94 1130 154 101 .2 1.74 .02 <.2

2S/11W-18L30 04-04-94 1550 156 99 <.2 1.42 <.01 <.2

(PR11 at 36 ft) 04-05-94 1550 154 99 .3 1.40 <.01 .2

04-06-94 1445 156 102 <.2 1.51 <.01 <.2

04-07-94 0930 158 105 .2 2.75 .09 <.2

09311 158 105 <.2 2.68 .10 <.2

09321 158 106 .3 2.69 .10 <.2

09331 159 105 .2 2.70 .10 <.2

04-08-94 1200 147 130 .2 5.89 1.11 .4

04-21-94 1315 140 125 <.2 5.22 2.23 <.2

06-01-94 1015 146 108 <.2 3.63 .39 .2
250 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

1Replicate analyses

Appendix 6. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during April and June 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate,

dissolved

(mg/L as N)

Nitrogen, 

nitrite,

dissolved

(mg/L as N)

 Orthophosphate,

dissolved

(mg/L as P)

POND AT PICO 04-05-94 0845 150 131 .3 5.43 1.46 1.7

(PR12) 04-05-94 0943 149 130 .2 5.28 1.48 1.5

04-05-94 1055 151 129 <.2 5.16 1.46 1.6

04-05-94 1154 150 128 <.2 5.24 1.37 1.7

04-05-94 1155 149 127 <.2 5.22 1.37 1.5

04-05-94 1421 149 125 .2 5.98 1.18 1.6

04-05-94 1607 147 129 <.2 6.17 1.17 1.3

04-05-94 1714 150 131 <.2 6.27 1.18 1.6

04-05-94 1830 150 134 <.2 6.48 1.21 1.5

04-06-94 0745 149 133 .3 5.97 1.36 1.7

04-07-94 0800 146 137 .3 6.25 1.58 1.5

04-07-94 0805 147 137 .2 6.31 1.59 1.3

04-07-94 0810 148 138 <.2 6.31 1.60 1.8

04-07-94 1430 144 135 <.2 5.98 1.59 1.5

04-07-94 1530 145 137 <.2 6.26 1.60 1.5

04-07-94 1540 144 136 <.2 6.06 1.59 2.0

04-07-94 1825 145 139 .4 6.40 1.62 1.6

04-07-94 1830 145 138 <.2 6.28 1.60 1.4

04-07-94 1845 144 137 .2 6.29 1.61 1.8

04-08-94 11301 145 136 <.2 5.95 1.73 1.6

11311 144 135 <.2 5.98 1.72 1.9

11321 145 134 .7 5.93 1.71 1.9

04-21-94 0800 140 129 <.2 4.74 2.43 1.3

04-21-94 0815 140 129 <.2 4.77 2.48 1.6

04-21-94 0820 138 129 <.2 4.81 2.45 1.2

04-21-94 0825 139 129 <.2 5.02 2.44 1.3

SEWAGE 04-05-94 0915 141 127 <.2 4.81 1.54 1.3

EFFLUENT 04-05-94 1020 149 131 .3 4.96 1.42 1.5

(PR13) 04-05-94 1105 142 123 <.2 5.22 1.42 1.0

04-05-94 1210 148 120 <.2 6.07 1.02 1.7

04-05-94 1420 149 134 .2 6.89 1.08 2.0

04-05-94 1545 148 141 .4 6.56 1.19 1.6

04-05-94 1650 148 140 <.2 — — 1.5

04-05-94 1835 148 140 <.2 7.70 1.30 1.9

04-06-94 1215 151 121 <.2 5.59 1.12 1.6

04-07-94 1215 140 124 <.2 5.51 1.11 1.0

04-08-94 1215 142 118 <.2 6.47 1.14 1.4

04-21-94 1530 134 136 <.2 4.31 1.06 1.7
Appendixes 251

Appendix 7. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during September 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved 

(mg/L)

Nitrogen,

nitrate

dissolved

(mg/L as N)

Nitrogen,

nitrite,

dissolved

(mg/L as N)

Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L14A 940906 1530 224 106 <0.2 0.67 <0.02 0.5

(MLS20) 940907 0915 195 133 <.2 8.74 1.26 <.4

940909 1030 136 139 .5 4.84 2.45 .5

940912 0845 134 119 <.2 5.67 1.98 1.2

940916 0830 134 134 1.4 2.89 1.28 1.2

940919 1925 137 124 <.2 5.86 .78 1.6

940922 0915 135 130 <.2 4.31 .30 1.1

2S/11W-18L14E 940906 1330 193 117 .6 10.27 .07 1.1

(MLS16) 1331 201 121 .2 10.38 .04 2.3

2S/11W-18L14F 940907 1035 142 129 <.2 4.53 1.78 .7

(MLS15) 940909 1000 136 139 <.2 4.54 2.75 1.3

940912 0850 131 112 <.2 5.88 1.81 1.1

940916 0900 133 132 .7 3.56 .15 1.3

940919 1430 137 119 <.2 6.64 .03 .9

940921 1145 137 133 <.2 4.85 <.02 2.5

940922 0920 135 134 <.2 4.78 <.02 1.5

2S/11W-18L14I 940916 1000 134 129 .4 4.40 .86 1.8

(MLS12) 940919 1545 134 115 <.2 6.50 .53 1.7

2S/11W-18L14J 940907 1215 147 123 .2 3.86 2.37 .8

(MLS11) 940912 1040 134 111 .4 5.49 1.82 1.7

2S/11W-18L14K 940909 1230 140 131 <.2 3.49 2.49 1.5

(MLS10)

2S/11W-18L27 940906 1440 194 105 .3 0.83 <.02 1.0

(PR8 at 49 ft) 940907 1150 199 107 <.2 .84 <.02 .3

940909 1315 210 106 <.2 .64 <.02 1.3

940912 1320 164 121 <.2 3.10 1.47 .2

940916 1150 146 124 <.2 5.12 2.51 .4

940919 2005 138 130 <.2 4.31 2.04 .3

940922 1215 134 126 <.2 4.27 1.82 <.4

Appendix 7. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during September 1994

[See table 1 for explanation of local identifier below station name; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less 

than value shown; —, no data; MLS, multilevel sampler; samples differing by one minute represent duplicate analyses]
252 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

Appendix 7. Water-quality data from analyses done in San Diego Geochemical Laboratory for samples collected near the research basin, Montebello 

Forebay, Los Angeles County, California, during September 1994—Continued

Station name

(Local identifier) Date Time

Sulfate,

dissolved

(mg/L)

Chloride,

dissolved

(mg/L)

Bromide,

dissolved

(mg/L)

Nitrogen,

nitrate

dissolved

(mg/L as N)

Nitrogen,

nitrite,

dissolved

(mg/L as N)

Orthophosphate,

dissolved

(mg/L as P)

2S/11W-18L28 940906 1210 226 108 <0.2 0.17 <0.02 1.1

(PR9 at 25 ft) 940907 0945 140 127 .5 3.81 1.95 <.4

940909 1045 134 140 <.2 4.86 3.37 <.4

940912 1430 130 112 <.2 5.59 2.54 1.7

940916 1325 134 134 <.2 3.29 2.55 1.1

940919 1815 135 120 .5 6.34 2.00 1.0

940922 1330 135 133 <.2 4.34 1.68 1.4

2S/11W-18L29 940906 1615 160 102 <.2 1.02 <.02 <.4

(PR10 at 60 ft) 940907 1435 160 100 <.2 1.02 <.02 <.4

940909 1530 171 102 1.2 1.02 <.02 1.4

940912 1000 168 98 <.2 1.43 .01 <.4

940916 1055 189 108 <.2 1.33 .33 .6

940919 1415 199 111 <.2 2.44 .50 2.4

940922 0930 168 129 <.2 3.98 1.72 .4

2S/11W-18L30 940906 1835 183 120 <.2 3.86 <.02 <.4

(PR11 at 36 ft) 940907 1520 168 125 <.2 6.09 1.22 .6

940909 1700 132 137 .3 4.90 3.21 1.9

940912 1100 139 120 .1 6.52 2.77 1.6

940916 0925 137 134 .4 3.05 2.58 3.3

940919 1600 135 121 .3 6.12 1.77 —

1601 133 122 <.2 6.09 1.73 3.4

940922 1115 136 132 .2 4.10 .93 1.2

POND AT PICO 940907 1515 133 149 <.2 5.11 1.66 .8

(PR12) 940909 1625 138 148 <.2 6.62 1.81 1.4

940912 1415 133 111 <.2 6.19 1.95 1.5

940916 1030 137 125 <.2 4.39 2.34 1.7

940919 1845 138 121 .2 7.07 2.64 1.7

940922 1345 136 129 <.2 5.80 2.43 —

940923 1145 137 130 <.2 5.57 2.34 1.8
Appendixes 253

Appendix 8A. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, oxygen–alkalinity[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25oC; ft, feet below basin floor or land 

surface; mg/L, milligrams per liter; —, no data]

Station name

(Local identifier) Date Time

 Oxygen, 

dissolved 

(mg/L)

(00300)

 pH, 

field 

(standard 

units)

(00400)

Specific 

conductance, field

(μS/cm) 

(00095)

Water 

temperature

(oC)

(00010)

Hardness, 

total 

(mg/L as 

CaC03)

(00900)

Calcium, 

dissolved 

(mg/L as Ca)

(00915)

 Magnesium, 

dissolved 

(mg/L as Mg)

(00925)

Sodium 

dissolved 

(mg/L as Na)

(00930)

Alkalinity, 

fixed 

endpoint, 

field 

(mg/L

as CaCO3) 

(39036)

2S/12W-24R1 04/07/94 1625 — 7.2 778 — 180 50 13 85 1502S/11W-19E1 04/07/94 1710 — 6.8 1,030 21.3 220 57 18 120 1602S/11W-19C1 04/06/94 1845 — 7 1,030 — 240 64 19 110 170

09/23/94 1340 2.4 7 1,060 22.4 — — — — 150

2S/11W-18P1 04/06/94 1745 — 6.9 1,030 20.2 220 59 18 120 160

09/23/94 1200 2.4 7 1,070 24.7 — — — — 180

2S/11W-18L35 09/21/94 1500 8.4 7.5 1,070 28.4 260 70 20 110 170(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510 5.6 7.6 1,060 20.3 370 110 22 80 210

09/12/94 1100 9 7.3 1,150 19.9 — — — — 22009/21/94 1030 8 7.2 1,140 19.8 400 120 25 83 220
254 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 8B. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, bromide–phosphorus [See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; mg/L, milligrams per liter; <, actual value less than value shown; —, no data] Station name (Local identifier) Date Time Bromide, dissolved (mg/L as Br) (71870) Chloride, dissolved (mg/L as Cl) (00940) Fluoride, dissolved (mg/L as F) (00950) Silica, dissolved (mg/L as SiO2) (00955) Sulfate, dissolved (mg/L as SO4) (00945) Nitrogen ammonia, dissolved (mg/L as N) (00608) Nitrogen nitrate, dissolved (mg/L as N) (00618) Nitrogen nitrite plus nitrate dissolved (mg/L as N) (00631) Nitrogen, nitrite, dissolved, (mg/L as N) (00613) Ortho- phosphate, dissolved (mg/L as P) (00671) 2S/12W-24R1 04/07/94 1625

—

—

— 16

— 0.02

— 9.9 <0.010 1.3

2S/11W-19E1 04/07/94 1710

—

—

— 21

— .49 2.49 2.5 .01 2.3

2S/11W-19C1 04/06/94 1845

—

—

— 18

— .03 5.38 5.4 .02 1.5

09/23/94 1340 <0.2 117 0.4

— 192

— 1.27 <.020 .7

2S/11W-18P1 04/06/94 1745

—

—

— 20

— .18

— 5 <.010 1.8

09/23/94 1200 <.2 140 .4

— 138

— 2.1

— <.020 3.4

2S/11W-18L35 09/21/94 1500 .12 130 .7 23 140 .03 4 6 2 1.2(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510

— 86

— 19 212 .01

— 3.3 <.010 .02

09/12/94 1100 <.2 89 .3

— 245

— 2.36 <.020 <.4

09/21/94 1030 .28 90 .3 20 240 <.010

— 2.7 <.010 .01
Appendixes 255

Appendix 8C. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, barium–chromium[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value 

shown; —, no data]

Station name

(Local identifier) Date Time

Barium,

dissolved 

(μg/L as Ba)

(01005)

Beryllium,

dissolved 

(μg/L as Be)

(01010)

 Boron,

dissolved

(μg/L as B)

(01020)

 Cadmium,

dissolved 

(μg/L as Cd)

(01025)

Chromium,

dissolved 

(μg/L as Cr)

(01030)

2S/12W-24R1 04/07/94 1625 97 <0.5 — <1 <52S/11W-19E1 04/07/94 1710 100 <.5 — <1 <52S/11W-19C1 04/06/94 1845 160 <.5 — <1 5

09/23/94 1340 — — — — —

2S/11W-18P1 04/06/94 1745 140 <.5 — <1 <5

09/23/94 1200 — — — — —

2S/11W-18L35 09/21/94 1500 200 <.5 470 <1 <5(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510 77 <.5 — <1 <5

09/12/94 1100 — — — — —09/21/94 1030 86 <.5 250 <1 <5
256 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 8D. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, cobalt–lithium [See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value shown; —, no data]Station name (Local identifier) Date Time Cobalt , dissolved 

(μg/L as CO)

(01035)

Copper,

dissolved

(μg/L as Cu)

(01040)

 Iron,

dissolved

(μg/L as Fe)

(01046)

Lead,

dissolved 

(μg/L as Pb)

(01049)

 Lithium,

dissolved 

(μg/L as Li)

(01130)

2S/12W-24R1 04/07/94 1625 <3 <10 6 20 92S/11W-19E1 04/07/94 1710 <3 10 7 <10 162S/11W-19C1 04/06/94 1845 5 10 31 <10 16

09/23/94 1340

—

—

—

—

—

2S/11W-18P1 04/06/94 1745 <3 10 11 <10 14

09/23/94 1200

—

—

—

—

—

2S/11W-18L35 09/21/94 1500 <3 20 8 <10 16(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510 <3 <10 6 <10 <4

09/12/94 1100

—

—

—

—

—

09/21/94 1030 <3 <10 7 <10 5
Appendixes 257

Appendix 8E. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, manganese–silver[See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; <, actual value less than value 

shown; -—, no data]

Station name

(Local identifier) Date Time

 Manganese,

dissolved 

(μg/L as Mn)

(01056)

Molybdenum, 

dissolved 

(μg/L as Mo)

(01060)

Nickel,

dissolved 

(μg/L as Ni)

(01065)

 Silver,

dissolved 

(μg/L as Ag)

(01075)

2S/12W-24R1 04/07/94 1625 38 20 <10 <12S/11W-19E1 04/07/94 1710 2 20 <10 <12S/11W-19C1 04/06/94 1845 460 30 <10 <1

09/23/94 1340 — — — —

2S/11W-18P1 04/06/94 1745 60 20 <10 <1

09/23/94 1200 — — — —

2S/11W-18L35 09/21/94 1500 800 30 <10 2(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510 4 <10 <10 <1

09/12/94 1100 — — — —09/21/94 1030 6 <10 <10 2
258 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California Appendix 8F. Water-quality data from selected production and monitoring wells, collected near the research basin, Montebello Forebay, Los Angeles County, California, strontium–oxygen 18/16 [See table 1 for explanation of local identifier below station name; number below the compound is the data parameter code, which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, feet below basin floor or land surface; μg/L, micrograms per liter; per mil, parts per thousand; <, actual value less than value shown; —, no data] Station name (Local identifier) Date Time Strontium, dissolved 

(μg/L as Sr)

(01080)

 Vanadium, 

dissolved 

(μg/L as V)

(01085)

 Zinc,

dissolved

(μg/L as Zn)

(01090)

 Hydrogen-2/1

(per mil)

(82082)

Oxygen-18/16 

(per mil)

(82085)

2S/12W-24R1 04/07/94 1625 360 <6 3 —

—

2S/11W-19E1 04/07/94 1710 470 8 14

—

—

2S/11W-19C1 04/06/94 1845 500 6 <3 —

—

09/23/94 1340

—

—

—

—

—

2S/11W-18P1 04/06/94 1745 470 6 6 —

—

09/23/94 1200

—

—

—

—

—

2S/11W-18L35 09/21/94 1500 560 10 360

—

—

(WPS at 20.6 ft)2S/11W-7J1 04/07/94 1510 620 <6 7 −57.5

−7.90

09/12/94 1100

—

—

—

—

—

09/21/94 1030 690 <6 <3 —

—
Appendixes 259

Appendix 9. Selected field measurements on samples collected for organic characterization, near the research basin, Montebello Forebay, Los Angeles 

County, California—Continued

Sample

identifier Date Time SC(μS/cm)

pH

(standard units)

Temperature,

water

(

oC)

Oxygen,

dissolved

(mg/L)

First recharge experiment

MLS4 08-23-93 0920 970 7.4 — —

MLS5 08-23-93 0945 960 7.7 — —

MLS6 08-23-93 1050 948 7.3 — —

MLS7 08-23-93 1100 976 7.5 — —

MLS8 08-23-93 1145 950 7.2 — —

MLS10 08-23-93 1210 958 7.4 — —

MLS11 08-23-93 1500 916 7.3 — —

PR8 08-23-93 1530 643 7.5 — —

PR9 08-23-93 1730 708 7.3 — —

PR12 (6 ft depth) 08-23-93 1920 954 7.6 — —

PR12 (surface) 08-23-93 1950 955 7.5 — —

PR13 08-23-93 2010 958 7.2 — —

Second recharge experiment

PR13 04-05-94 0730 1,100 7.1 23.3 4.6

MLS4 04-05-94 1300 1,133 6.9 20.1 5.5

PR10 04-05-94 1400 — — — —

PR11 04-05-94 1530 930 6.9 22.5 .5

PR9 04-05-94 1700 918 7.0 20.9 .7

PR8 04-05-94 1900 953 6.8 21.5 .7

MLS7 04-06-94 0900 1,084 7.0 20.7 2.3

MLS10 04-06-94 1100 1,112 7.0 20.7 5.1

MLS15 04-06-94 1200 1,087 7.0 22.1 3.9

PR12 04-06-94 1500 1,145 7.1 24.2 4.4

2S/11W-18P1 04-06-94 1730 1,047 6.7 20.2 1.2

2S/11W-19C1 04-06-94 1900 1,051 6.9 19.2 1.4

MLS20 04-07-94 0945 1,041 6.89 21.7 2.4

PR9 04-07-94 1200 1,045 6.76 22.4 .8

2S/11W-7J1 04-07-94 1430 1,082 7.12 20.4 5.6

MLS4 04-07-94 1700 1,165 6.98 22.8 .8

MLS5 04-07-94 1705 1,153 6.93 23.0 1.4

MLS6 04-07-94 1710 1,147 6.92 23.0 1.9

MLS7 04-07-94 1715 1,137 6.89 22.9 2.2

MLS8 04-07-94 1720 1,142 6.94 22.9 2.4

MLS9 04-07-94 1725 1,134 6.89 22.9 2.4

MLS10 04-07-94 1730 1,147 6.92 22.7 4.3

MLS11 04-07-94 1735 1,149 6.95 22.6 5.1

MLS12 04-07-94 1740 1,148 6.96 22.4 4.3

MLS13 04-07-94 1745 1,137 6.92 22.5 2.2

MLS14 04-07-94 1750 1,138 6.92 22.7 2.5

MLS15 04-07-94 1755 1,136 6.97 22.3 2.3

MLS16 04-07-94 1800 1,114 6.92 22.4 2.3

Appendix 9. Selected field measurements on samples collected for organic characterization near the research basin, Montebello Forebay, Los Angeles 

County, California

[SC, specific conductance; μS/cm, microsiemens per centimeter at 25oC; oC, degrees Celsius; mg/L, milligrams per liter; ft, foot; —, no data]
260 Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water, Los Angeles County, California

MLS17 04-07-94 1805 1,132 6.93 22.3 2.3

MLS18 04-07-94 1810 1,127 6.92 21.9 2.4

MLS19 04-07-94 1815 1,113 6.89 21.9 1.7

MLS20 04-07-94 1820 1,047 6.94 21.7 1.9

Third recharge experiment

PR9 09-19-94 1815 1,065 7.1 27.4 0.6

2S/11W-7J1 09-21-94 1030 1,144 7.2 19.8 8.0

MLS15 09-21-94 1145 1,090 7.2 27.5 1.2

WP5 09-21-94 1500 1,068 7.5 28.4 8.4

PR11 09-22-94 1115 1,075 7.2 27.7 .6

PR13 09-22-94 1345 1,084 7.2 28.3 3.0

Appendix 9. Selected field measurements on samples collected for organic characterization, near the research basin, Montebello Forebay, Los Angeles 

County, California—Continued

Sample

identifier Date Time SC(μS/cm)

pH

(standard units)

Temperature,

water

(

oC)

Oxygen,

dissolved

(mg/L)