v>EPA
United States
Environmental Protection
Agency
Municipal Environmental Research EPA-600/2-78-076
Laboratory June 1978
Cincinnati OH 45268
Research and Development
Water Factory 21:
Reclaimed Water,
Volatile Organics,
Virus, and
Treatment
Performance
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. Special” Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-076
June 1978
WATER FACTORY 21:
RECLAIMED WATER, VOLATILE ORGANICS, VIRUS,
AND TREATMENT PERFORMANCE
by
Perry L. McCarty, Martin Reinhard,
Carla Dolce, and Huong Nguyen
Civil Engineering Department
Stanford University
Stanford, California 94305
and
David G. Argo
Orange County Water District
Fountain Valley, California 92708
Grant No. EPA-S-803873
Project Officer
John English
Wastewater Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIHER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does men-
tion of trade names or commercial products constitute endorsement or recoin—
mendation for use.
11
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FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and Integrated attack on the problem,
Research and development is that necessary first step in problem solu-
tion and It Involves defining the problem, measuring its Impact, and search-
ing for solutions. The Municipal Environmental Research Laboratory develops
new and improved technology and systems for the prevention, treatment, and
management of wastewater and solid and hazardous waste pollutant discharges
from municipal and community sources, for the preservation and treatment of
public drinking water supplies, and to minimize the adverse economic, social,
health, and aesthetic effects of pollution. This publication Is one of the
products of that research; a most vital cóimnunications link between the re-
searcher and the user community.
This report describes the performance of Water Factory 21, a 0.66 m 3 /s
advanced wastewater treatment plant designed to treat municipal wastewater so
that it can be used to recharge a groundwater system. Through this project
groundwater supplies are being replenished, saltwater—endangered aquifers are
being protected, and water Is being reclaimed for future use.
Francis T. Mayo, Director
Municipal Environmental
Research Laboratory
111
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ABSTRACT
Water Factory 21 is a 0.66 rn 3 /s (15 mgd) advanced wastewater treatment
plant designed to improve the quality of biologically treated municipal waste-
water so that it can be used to provide the injection water for a seawater
barrier system. Processes included are lime treatment, ammonia stripping,
breakpoint chlorination, filtration, activated—carbon adsorption, reverse os-
mosis, and final chlorination. Because of interest in the use of reclaimed
water to augment the domestic water supply, this study was initiated to eval-
uate the effluent quality and efficiency of treatment for inorganic, organic,
and biological contaminants. This report covers the first one and one—half
years of plant operation.
Chemical clarification with lime at pH greater than 11.3 removed 60 per-
cent of the influent COD, 99 percent of the phosphates, and greater than 50
percent of the barium, cadmium, chromium, copper, iron, lead, manganese, sil-
ver, and zinc. Removal of mercury, selenium, and arsenic were minimal.
Ammonia stripping with two towers in series removed an average 82 percent of
the influent ammonia, and was highly effective in reducing the concentrations
of a wide range of low molecular weight and non—polar organics such as one—
and two—carbon halogenated organics, chlorinated benzenes, and hydrocarbons.
These in general were not removed efficiently by other processes.
Activated—carbon adsorption was effective not only for general COD re-
moval, but also for the removal of a wide range of specific organic compounds
such as chlorinated benzenes and aromatic hydrocarbons, many of which are of
toxicological significance. This process in combination with the others re-
sulted in an overall COD removal of 90 percent, producing an effluent with a
mean COD of 15 mg/i.
Breakpoint chlorination (9:1 weight ratio of Cl 2 to N11 3 —N) is effective
in reducing ammonia nitrogen to 1 mg/i; however, it results in the production
of relatively high concentrations of chlorinated organics, particularly the
haiofornis, if carried out before carbon adsorption, and depresses pH if prac-
ticed following carbon adsorption. The latter point of application is prob-
ably best for breakpoint chlorination as it minimizes effluent organics and
pH control is technically feasible. Pilot studies with reverse osmosis indi-
cated removals of 95 percent for general inorganics and 93 percent for COD.
However, haloforms, chlorinated benzenes, and other low molecular weight or—
ganics were not removed.
Most influent samples taken were positive for virus and the presence of
over 25 different viruses was verified. However, of 77 effluent samples ana-
lyzed, only one was positive for virus, and contained one plaque of Polio
Type 2. This single incidence appears to have been associated with an occa-
sional problem of activated—carbon fines in the effluent.
iv
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This report is a progress report submitted In partial fulfillment of
Research Grant No. EPA—S—803873 by the Orange County Water District under
sponsorship of the U.S. Environmental Protection Agency. This report covers
the period of January 1, 1976, to July 31, 1977, and was completed January 1,
1978.
V
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CONTENTS
Foreword
Abstract
Figures
Tables
Acknowledgments
111
iv
viii
ix
x
18
18
19
19
28
48
55
55
55
56
57
60
60
64
66
71
1
2
4
5
5
8
10
10
10
10
15
1. Introduction
2. Conclusions
3. Recommendations
4. Water Factory 21
General Description .
Process Description .
5. Sampling and Analytical Procedures
Sampling
General Inorganics and Heavy Metals
Organics
Viruses
6. Results
Characteristics of Influent Water
Treatment Plant Performance . .
General Inorganics and Heavy Metals
Organics
Virus
7. Discussion
Background
General Inorganics
Heavy Metals
Organics
Virus
Plant Reliability
References
Appendices
A. Major Design Criteria, OCWD 0.66 1n 3 /s Advanced Wastewater
Treatment Plant
B. Summary Analyses for General Constituents, Trace
Inorganics, Radioactivity and Pesticides
vii
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FIGURES
Number Page
1 Processes and sampling locations at Water Factory 21 . . . . 6
2 Variation in flow rate at Water Factory 21 during the two
periods of this study 7
3 Haloform concentrations after October 1976 when breakpoint
chlorination was initiated; upper: filtration effluent (Q6);
lower: plant effluent (Q9) 33
4 Chromatograms of CLS extracts with simultaneous flame
ionization and electron capture detection. A: Q2 taken
6/12—13/1977; B: Q9 taken 6/12—13/1977 (numbers refer to
Table2S) 40
5 ECD—chromatogram (setting 337/2k) of Qi extract, internal
standard 2.34 ig/l. 1: diethylphthalate; 4: dioctyl—
phthalate; 3: retention time as lindane; 2: unknown . . . 41
6A Pesticide standard (ECD setting 337/2 ). 1: BHC isomers
260 pg; 2: lindane 260 pg; 3: heptachior 160 pg; 5: aidrin
160 pg; 7: dieldrin 160 pg; 8: DDE 194 pg; 9: endrin 170
pg; 10: TDE 500 pg; 11: DDT 240 pg; i.s.: internal stan-
dard, 1170 pg; 4, 6: impurities 42
6B PCB arochior 1242 standard, 2.66 ng; internal standard, 0.464
ng. Detector 337/2k 42
7 Typical total ion chromatogram (computer reconstructed) of
a CLS extract from Q2. Lower graph is independently
normalized. Numbers refer to substances in Table 25 . . . 47
8 Probability plot of virus assay levels 50
9 Seasonal variation In natural viruses in Water Factory 21
influent 52
A—l Reverse osmosis plant flow diagram 70
V1i]
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TABLES
Number Page
1 Water Factory Sampling Schedule, January 1976 through June
1976 11
2 Water Factory Sampling Schedule, October 1976 through June
30, 1977 12
3 General Analytical Procedures 13
4 Summary of Virus Concentration Methods 16
5 Mean Characteristics of Secondary Effluent Treated at
Water Factory 21 18
6 Mean Characteristics of Treated Water and Regulatory
Requirements, January 1976 through June 1976 20
7 Changes in General Parameters by Chemical Clarification,
January through June 1976 (Monthly Mean Values) 21
8 Chemical Clarification. Heavy Metals Removal, January
through June 1976 21
9 Ammonia Removal by Stripping, January through June 1976 . . . 22
10 Heavy Metals Removal by Carbon Adsorption, January through
June1976 23
11 Mean Characteristics of Treated Water and Regulatory
Requirements, October 1976 through June 1977 24
12 Changes in General Parameters by Chemical Clarification,
October 1976 through June 1977 (Monthly Mean Values) . . 26
13 Effect of Chemical Treatment on Heavy Metals, October 1976
through June 1977 27
14 Effectiveness of Ammonia Stripping Process, October 1976
through June 1977 27
15 Filter Performance for Turbidity Reduction, October 1976
through June 1977 28
ix
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TABLES (continued)
Number Page
16 Heavy Metals Removal by Activated Carbon, October 1976
through June 1977 29
17 COD Removal by Water Factory 21 30
18 TOC Removal by Water Factory 21 30
19 Haloforin Concentrations Prior to Breakpoint Chlorination,
January 1976 through June 1976 31
20 Haloform Concentrations during Second Period, October 1976
through June 1977 32
21 Concentrations of Highly Volatile Constituents Other than
Haloforms ( tg/l), October 1976 through June 1977 . . . . 35
22 Closed—Loop Stripping Analyses for Selected Organics,
October 1976 through June 1977 36
23 Efficiency of Ammonia Stripping and Carbon Adsorption for
Removal of Selected Trace Organics Based upon Paired
Samples 38
24 PCBs and Phthalate Concentrations at Various Sampling
Points, April 1977 through June 1977 43
25 Compounds in WF—2l Samples Analyzed by CLSA and Their TIC
Peak Heights Relative to the Internal Standard, 1—C1—C8 . . 45
26 Substances Tentatively Identified in Hexane Extracts . . . . 46
27 Virus Concentration in Influent (Q1) 49
28 Viruses Identified in Water Factory 21 Influent (Qi) . . . . 51
29 Virus Concentration in Chemical Clarifier Effluent (Q2),
November 1975 through June 1976 53
30 Variability of Inorganic Constituents in Water Factory 21
Effluent 61
31 Variability of Organic Constituents in Water Factory 21
Effluent 62
x
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ACKNOWLEDGMENTS
Ms. Betsy Martin, Orange County Water District, participated in field
virus concentrations for this project. Dr. Lawrence Leong and Dr. Rhodes
Trussell, Project Engineers with James N. Montgomery, Consulting Engineers,
Inc., were responsible for viral assay and technical direction for this phase
of the project, respectively.
Appreciation is extended to the California Department of Public Health
for their conducting the extensive virus assays for this project, and to
David Dickson, Research Assistant, Stanford University, who assisted in anal-
yses for organic constituents.
In addition to the support provided by the Orange County Water District
and the U.S. Environmental Protection Agency, project financial assistance
was provided by OWRT, U.S. Department of the Interior through Grant 14—34—
0001—7503, the California Department of Water Resources through Grant No.
B52353, and various member agencies of WaterCare.
xi
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SECTION 1
INTRODUCTION
The Orange County Water District (OCWD) has constructed Water Factory 21
and a series of injection wells near the Pacific Coast in order to reduce sea-
water intrusion into the groundwater supply by recharge of reclaimed waste—
water (9). Water Factory 21 is a 0.66 m 3 /s (15 mgd) advanced wastewater
treatment plant which was designed to improve the quality of biologically
treated municipal wastewater so that it could be used to provide the injection
water needed for the seawater barrier system. Processes included in this f a—
cility are lime treatment for suspended solids and heavy metal removal, ammo-
nia stripping and breakpoint chlorination for nitrogen removal, filtration
and activated—carbon adsorption for organics and additional suspended solids
removal, reverse osmosis for demineralization, and final chlorination for
disinfection.
Because of the high quality of water reclaimed by Water Factory 21, in-
terest has increased in the potential of using the reclaimed and injected
wastewater to augment the domestic water supply. However, inadequate knowl-
edge of inorganic, organic and biological constituents remaining after ad—
vanced wastewater treatment has caused concern among health agencies respon-
sible for protecting the safety of groundwater supplies. Because of such
concern, this study was undertaken to: (1) characterize the quality of Water
Factory 21 effluent, (2) assess the reliability of treatment plant operation
for removal of trace contaminants, and (3) evaluate the effectiveness of the
individual processes and processes in combination for removing materials of
public health concern.
This report is a summary of the results of inorganic and organic analy-
ses, viral assays, and an evaluation of the performance for the first one
and one—half years of operation of Water Factory 21.
1
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SECTION 2
CONCLUSIONS
The results of the first one and one—half years of operation of Water
Factory 21 have indicated that the advanced wastewater treatment plant is
capable of removing a variety of inorganic, organic, and biological contami-
nants present in trickling filter treated municipal wastewater.
Chemical clarification with lime at a pH greater than 11.3 resulted in
more than 50 percent reduction in the concentration of trace heavy metals
such as barium, cadmium, chromium, copper, iron, lead, manganese, silver, and
zinc. Mercury, selenium, and arsenic were not removed significantly by this
process. The lime process also removed 60 percent of the influent COD, only
a portion of which was In suspended form, and 99 percent of the influent
phosphates.
Following lime clarification ammonia stripping with two towers operated
in series removed an average of 82 percent of the influent ammonia. In ear—
her studies with the towers operated in parallel, removal was only 56 per-
cent. In addition, ammonia stripping resulted in a high degree of removal of
a variety of low molecular weight organic compounds, many of which were not
efficiently removed by the other processes in the treatment system, such as
activated—carbon adsorption and reverse osmosis. Included in the compounds
removed were several chlorinated organics. This indicates that air stripping
can be an important complementary process for removal of trace organic mate-
rials.
Activated—carbon adsorption was effective not only for general COD re-
moval but also for the removal of a wide range of specific organic compounds,
many of which are of toxicological significance. This process in combination
with the others resulted in an overall COD removal of 90 percent, producing
an effluent with a mean COD of 15 mg/i.
Breakpoint chlorination at a weight ratio of 9 parts chlorine to 1 part
ammonia nitrogen was effective for reducing the ammonia nitrogen concentra-
tion to 1 mg/i. However, this process also caused the production of high
concentrations of chlorinated organics such as the haloforms, created prob—
lems in pH control, and adversely affected the effectiveness of activated—
carbon adsorption. These problems except p11 control are minimized if break-
point chlorination is practiced after rather than before activated carbon.
Virus were present In most samples of secondary treated wastewater re-
ceived at Water Factory 21. The advanced wastewater treatment was effective
In removal of the virus as only one was found in the 77 samples of final
2
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effluent analyzed. The appearance of this single virus appears to have been
related to an operational problem which resulted in the escape of activated—
carbon fines in the effluent.
Pilot plant studies indicated that reverse osmosis was effective in re-
moving about 95 percent of the total dissolved solids in advanced treated
effluent. It also removed 93 percent of the organics as measured hy the COD
test, although many trace organics with low molecular weight such as the
haloforms were not removed by this process.
The combined advanced wastewater treatment processes employed at Water
Factory 21 are capable of meeting the regulatory requirements for injection
water as needed for the seawater barrier system. They also show promise for
producing a water which may satisfy public health concerns associated with
mixing of the injected water with groundwater in an aquifer used for general
municipal purposes.
3
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SECTION 3
RECOMMENDATIONS
This study has provided extensive data which can be used to evaluate the
effectiveness of advanced wastewater treatment for removing inorganic, organ1 ,
and biological materials of public health concern. Problems which require
further evaluation are indicated in the following.
The effect of breakpoint chlorination or a free chlorine residual on the
capacity of activated carbon, and its potential for release of specific orga-
nic materials from activated carbon needs further study.
Breakpoint chlorination results in the formation of high concentrations
of several chlorinated organics of public health concern. The low nitrogen
requirement which necessitated the use of breakpoint chlorination should be
reevaluated. The potential benefits from the required ammonia nitrogen con-
centrations of 1 mg/l in the injection water are offset by a high cost for
breakpoint chlorination, increased concentrations of chlorinated organics,
and reduced treatment plant reliability. Also, operational procedures which
will minimize chlorinated organic formation need to be developed.
Activated—carbon fines cause problems when present In effluents from ad-
vanced wastewater treatment systems including clogging of reverse osmosis
membranes and well injection systems, as well as Increasing the potential for
pathogen passage through the system. Methods for reducing activated—carbon
fines need to be explored.
The program for measuring trace organics needs to be modified to allow
more frequent and precise quantification for those specific organics which
are of health concern. For these materials, the individual treatment proces-
ses should be more closely evaluated to determine the effect of operational
variables on the efficiency of removal. Because of time and expense, this
may necessitate modification of the routine monitoring program.
Many organics are not measureable by currently available analytical tech-
niques. In order to gain some Idea of the health risks associated with such
materials, some method of biological testing of the organics, such as bac-
terial mutagenicity should be instigated and the results should be compared
with those from alternative supplies.
4
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SECTION 4
WATER FACTORY 21
GENERAL DESCRIPTION
The wastewater reclamation plant was designed to treat 0.66 in 3 /s (15 mgc
of municipal trickling filter effluent by the processes indicated in Figure 1.
These Include lime clarification with sludge recalcining, ammonia stripping,
recarbonation, breakpoint chlorination, mixed—media filtration, activated—
carbon adsorption and carbon regeneration, post—chlorination, and reverse os—
inosis (RO) demineralization.
The plant operation covered in this report has been divided into two
distinct periods. Plant operation began in January of 1976 and was main-
tained continuously through June, 1976. During this period the water being
treated was not injected, the plant was operated for the specific purpose of
gathering data to determine treatment capability. Following a plant shutdown
which occurred during July, August and September of 1976 for routine mainte-
nance and modifications, operations were restarted in October and were main-
tained continuously for the duration of the study period. Figure 2 illus-
trates the variation in flow rate through the plant during these two periods
of operation. Generally, plant flows were maintained in the 0.22 to 0.26 m 3 Is
range.
Water Factory 21 is composed of dual unit processes which allow the indi-
vidual units to be operated near design capacity even when the total system
was operated at reduced flow. Typical flow rates for the various processes
are as follows:
Process
Normal Percent of Design
Flow Rate
Prior
to
October 1976
After
October
1976
Lime Clarification
100
80
Ammonia Stripping
100
40
Recarbonation
50
80
Filtration
100
100
Carbon Adsorption
100
100
Final Chlorination
20
40
5
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CHLORINATION
CHEMICAL
CLARIFICATION
ACTIVATED
CARBON
ADSORPTION
Processes and sampling locations at Water Factory 21.
0 1
C l 2
08
109 EFFLUENT
AIR
LIME
SLUDGE
CO 2
AMMONIA
STRIPPING
RECARBONATION
REVERSE
OSMOSIS
FILTRATION
Figure 1.
6
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.4
.3
(I)
E
IJJ
I-
0
-J
0
MONTH OF OPERATION
Figure 2. Variation in flow rate at Water Factory 21 during the two periods of this study.
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PROCESS DESCRIPTION
The individual processes at Water Factory 21 are illustrated in Figure 1.
The major design criteria for each process are listed in detail in Appendix A.
A general description of each process is given in the following.
Chemical clarification is accomplished in separate rapid mix flocculation
and sedimentation basins. Lime is used as a primary coagulant and is added
in slurry form to the rapid mix basin. Lime feed is automatically controlled
to achieve an optimum pH of 11.3. A lime dose of 350 to 400 mg/l as calcium
oxide is sufficient to maintain this pH. The three—stage flocculation basins
are operated with G values of 100, 25, and 20 s_i in the first, second, and
third flocculation basins, respectively. Detention time in the flocculation
basin is approximately ten minutes in each compartment. An anionic polymer,
Dow A 23, is used as a settling aid in the third—stage basin. A polymer dose
of 0.1 mg/i is usually added as a settling aid to improve clarification. The
water flows from the bottom of the third flocculation basin into a settling
basin. The settling basin is also equipped with inclined settling tubes to
improve clarification. This process has been found effective for reducing
turbidity, phosphates and suspended solids.
Following settling, ammonia stripping Is accomplished in a countercur-
rent induced draft tower at an air to water ratio of 3000 m 3 /m 3 . The depth
of the polypropylene splash bar packing is 7.6 m. Each tower was originally
designed to operate Independently; however, due to poor initial ammonia re-
movals, the towers were modified to operate in series. Performance prior to
modification had Indicated ammonia removals of 50—65 percent. Fcllowing the
tower modification, removals have been increased to 80—85 percent.
Breakpoint chlorination has been practiced since October, 1976, for ni-
trogen control. It was found that a chlorine to ammonia nitrogen weight
ratio of 9 or greater was required to decrease ammonia nitrogen levels to 1
mg/i or less. Three different locations for breakpoint chlorination were
evaluated: just after ammonia stripping, while pH is high; between first and
second stage recarbonation; and in conjunction with final chlorination. Each
location was found to have relative advantages and disadvantages.
In the recarbonation process, carbon dioxide is added to lower pH to ap-
proximately 7.5. The recarbonation basin also served as a chlorine contact
chamber during some portions of this study to allow detention time for break-
point chlorination reactions to occur.
Following the recarbonation basin, the effluent passes through open
gravity mixed—media filter beds designed for a hydraulic loading rate of
0.2 in 3 /m 2 —min. The filter media is 0.76 m deep and consists of layers of
coarse coal, silica sand, and garnet. It is supported by a layer of silica
and garnet gravel with a Leopold underdrain. Alum (11 mg/l) and polymer
(0.05 mg/l) are added to improve clarification.
The water is then pumped through packed—bed, upflow pressure contactors
filled with Calgon Filtersorb 300 granular activated carbon. There are 17
8
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contactors each operating in parallel and with an empty bed contact time of
30 minutes. The hydraulic loading rate for each column is 0.2 m 3 /m 2 —min.
Following activated—carbon treatment the effluent flows to the final
chlorination basin for post—chlorination, followed by 30 minutes of contact
time at the design flow of 0.66 m 3 /s.
A 0.22 m 3 /s reverse osmosis plant will treat a portion of the reclaimed
water following activated—carbon treatment, so that when blended with the re-
maining portion, an adequate reduction in total dissolved solids can be ob-
tained. During this study the full—scale reverse osmosis plant was under
construction, but effluent was available for evaluation from a 0.9 m 3 /h pilot
plant using spiral—wound membrane elements. The pilot RO plant was operated
on either activated—carbon effluent or mixed—media filter effluent. A flow
diagram of the full—scale reverse osmosis plant is shown in Appendix A Figure
A—l. The plant incorporates feeding sodium hexametaphosphate as a scale
precipitation inhibitor, 25 p cartridge filtration, prechiorination and pH
control with sulfuric acid.
9
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SECTION 5
SAMPLING AND ANALYTICAL PROCEDURES
SAMPLING
Analyses for chemical oxygen demand (COD), total organic carbon (TOC),
inorganic constituents, and heavy metals were conducted by the Water Factory
21 analytical laboratory. Viral analyses were conducted by James Montgomery
Engineers, Pasadena, California. Specific organic constituents were analyzed
in the Stanford Water Quality Control Research Laboratory. Grab and composite
samples were stored under refrigeration prior to organic analysis. Composite
samples were prepared by mixing equal volumes of nine grab samples taken at
three—hour intervals over a 24—hour period. Samples analyzed at Stanford were
shipped by air in insulated containers, and arrived on the same day. Specific
methods used in sample preservation prior to analysis are given under the
specific analytical procedures which follow. Sampling locations are desig-
nated by numbers preceded by the letter Q in Figure 1.
GENERAL INORGANICS AND REAVY METALS
The sampling and analytical procedures for general inorganics and heavy
metals are described for two distinct periods. First is the period prior to
injection and encompasses January, 1976, through June 1976. The other period
coincides with the start of injection, from October 1976, through June, 1977.
Table 1 indicates the sampling schedule and frequency for all inorganic and
heavy metals analyses prior to October, 1976, and Table 2 for the period after
October, 1976. The major difference between the two schedules is a decrease
in heavy metals sampling frequency from daily composites during the first pe-
riod to weekly composites for the second period. Also, additional samples
from the pilot RO unit were taken during the second period. All analyses
were conducted in accordance with Standard Methods (1). Table 3 summarizes
the particular procedures from Standard Methods used for each parameter.
ORGANICS
COD and MBAS were determined on composite samples using the standard
procedures listed in Table 3. TOC was determined on composite samples using
a Beckman 915A TOC analyzer. The characterization of trace organic substances
in water was performed for a number of selected substances on a routine basis.
A broad and detailed characterization was attempted with some of the samples.
In the following, the three basic procedures for the routine analysis of or—
ganics are described: VOA (volatile organic analysis), CLSA (closed—loop
10
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TABLE 1. WATER FACTORY 21 SANPLING SCHEDULE
January 1976 through June 1976
— Parameter
Sample Points
Plant Clarifier
Influent Effluent
1 Q2
Ammonia
Tower ill
Effluent
Q3
Ammonia
Tower //2
Effluent
Q4
Recarb.
Interned.
Settling
Q5A
Recarb.
Basin
Effluent
Q5
Filter
Effluent
Q6
Carbon
Effluent
Q8
Chlorine
Contact
Basin
Effluent
Q9
T.mperature 1
pit
EC
Turbidity
NH 3 -N
Total & Free
Chlorine Res.
TOC
COD
MBAS
Phenol
Cyanide
Trace Elements 3
Alkalinity
Calcium
Mg
Total Hardness
Sodium
Sulfate
Chloride
P0 4 —P
TKN
ORG—N
F
B
Coliform
Virus 4
Color
2G
26
2G
OC
DC
PC
PC
PC
Vc
PC
DC
PC
DC
PG
2G
2G
20
26
20
DC
DC
DC
PC
DC
PC
DC
PG
C
26
20
PG
26
20
PG
26
26
PG
PG
20
2G
PG
PG
26
DC
vc
PC
DC
PG
20
26
2
DC
vc 2
vc 2
PC
26
(2G)
(26)
2G
2G
(PC )
(PC)
(DC I
DC )
( DC )
(PC)
( DC)
(PC )
( DC)
( DC)
PC
PC
(VGJ
C
DC — Daily composite (1 grab every 4 hr. 500 ml sample) 1 Air and water in and out.
O — Grab sample 2
Each carbon column
DG — Daily grab sample 3
26 — One grab every 2 hr. (day shift only) Trace elements include: arsenic, chromium (VI),
CM — Once per month grab barium, copper, mercury, selenium, cadmium, silver,
lead, zinc, Fe, Mn.
LEGEND: Test by operations lab. 4
Te t by t b Sampli ’ ig and concentration on—site by B. Martin.
analysis by Montgomery Engineers
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TABLE 2. WATER FACTORY 21 SAMPLING SCHEDULE
October 1976 through June 30, 1977
p,)
Parameter
Sample Points
Plant Clarifier
Influent Effluent
Qi Q2
Ammonia
Tower #1
Effluent
Q3
Ammonia
Tower 02
Effluent
Q4
Recarb.
Intermed.
Settling
Q5A
Recarb.
Basin
Effluent
Q5
Filter
Effluent
Q6
Carbon
Effluent
QS
Chlorine
Contact
Basin
Effluent
Q9
HO Plant
Influent
Q2 IA
RO Plant
Effluent
g2 1 5
pH
EC
Turbidity
NH 3 -N
Total Free
Chlorine Has.
TOC
COD
IIBAS
Phenol
Cyanide
Trace Elements
Alkalinity
Calcium
Hg
Total Hardness
Sodium
Sulfate
Chloride
P0 4 -P
TKN
ORG—N
F
B
Colifonu
Virus ’
Color
DC
DC
CA
DC
DC
WC
WC
WC
WC
WC
DC
DC
DC
WC
WG
D C
20
DC
CA
2C
DC
WC
WC
DC
DC
DC
WC
WG
26
20
20
DC
20
20
2G
26
20
CA
DC
DC
WC
WC
WC
WC
SC
WC
WC
WC
DC
20
20
WC
WC
WC
DC
DC
WC
WG
DC
WC
DC
DC
DC
DC
DC
DC
D C
DG
DC
DC
DC — Daily composite (1 grab every 4 hr. 500 ml sample)
C — Grab sample
DC — Daily grab sample
2G - One grab every 2 hr. (day shift only)
CM - Once per month grab
WC — 24 hr composite taken once per week
CA — Control panel value — online instrument average
WC — Grab sample once per week
Trace elements include: arsenic, chromium (V I), barium, copper, meroury, selenium, cadmium, silver, lead, zinc, Fe, Mn.
Sampling and concentration on—site by B. Martin, analysis by Montgomery Engineers.
-------
TABLE 3. GENERAL ANALYTICAL PROCEDURES
Parameter
Method
Page Number from
Standard Methods
(1),l4th Edition
conductivity @ 25°C direct, specific conductance meter 71
pH direct, pH meter 460
total dissolved glass fiber filtration, water bath
solids (TDS) (100°C) and oven drying (180°C) 92
calcium titration with EDTA 189
magnesium atomic absorption, flame 148
sodium atomic absorption, flame 250
potassium atomic absorption, flame 234
aluminum atomic absorption, graphite furnace 148
iron atomic absorption, graphite furnace 148
manganese atomic absorption, graphite furnace 148
silver atomic absorption, graphite furnace 148
arsenic atomic absorption, graphite furnace 148
barium atomic absorption, graphite furnace 148
cadmium atomic absorption, graphite furnace 148
chromium atomic absorption, graphite furnace 148
copper atomic absorption, graphite furnace 148
lead atomic absorption, graphite furnace 148
selenium atomic absorption, graphite furnace 148
zinc atomic absorption, graphite furnace 148
mercury flameless atomic allsorption 156
alkalinity as CaCO 3 , titration with H 2 S0 4 278
chloride titration with Hg(N03)2 304
fluoride specific ion electrode 391
sulfate turbidimetric 496
phosphate ascorbic acid 481
nitrate—nitrogen brucine sulfate 427
ammonia—nitrogen 1. Kjeldahl method 438
2. phenate method 416
organic—nitrogen Kjeldahl 437
boron curcumin 287
methylene blue active
substance (MBAS) methylene blue 600
chemical oxygen
demand (COD) dichromate digestion 550
silica molybdosilicate 487
hardness, total EDTA 202
phenol colorimetric (AAP) 582
dissolved oxygen iodometric, azide modification 443
dissolved sulfide methylene blue 503
coliform membrane filter 928
fecal coliform membrane filter 937
color visual comparison 64
cyanide distillation and colorimetric 361
Table 3 continued
13
-------
Table 3 continued
Parameter
Method
Page Number from
Standard Methods
(l),l4th Edition
residual chlorine
odor
radioactivity
gross alpha
gross beta
1. amperometric
2. DPD
threshold procedure
internal proportional count.
internal proportional count.
322
332
*
648
648
*flMethods for Chemical Analysis of Water and Wastes,” page 287, EPA—625—6—
74—003 (1974).
stripping analysis), and SEA (solvent extraction analysis). The procedures
and findings of the detailed characterization are given in Section 6.
VOA
Organics with high volatility were determined by stripping, concentration
on a porous polymer trap, and gas chromatography (Tracor MT—220) using a Hall
electrolytic conductivity detector as described by Bellar and Lichtenberg (2),
but as modified by Symons et al. (3). One ml of 0.1! sodium thiosulfate was
added to 50—mi vials at the time of grab sample collection to reduce residual
chlorine. Organics measured include most haloforms, and various other chlori-
nated one— and two—carbon organics. Concentrations measured were 0.1 pg/l
and higher.
CLSA
Closed—loop stripping by the Grob procedure (12) allows analysis for a
broad range of volatile organics present in the ng/l range and above, such as
solvents, petroleum products, and chlorobenzenes. However, it is not very ef-
fective in quantitatively analyzing for haloforms in the pg/i range. Organics
in 200 to 500 ml of composite sample were removed by recirculation for two
hours of a small volume of air through the sample and over an activated char-
coal filter. The filter was extracted with 20 p1 of CS 2 , approximately 10 p1
of which could be recovered. An aliquot of 2 p1 was used for high resolution
gas chromatographic (CC) analysis (Finnigan 9610), using a glass capillary
column (25 in UCON KB, Jaeggi Laboratory for GC, Trogen, Switzerland) and flame
ionization detection (FID). The gas chromatograph was equipped with a Grob
type injector (Brechbiihler AG, Urdorf, Switzerland). In May, an effluent
stream splitter was introduced for simultaneous flame ionization and electron
capture detection. For mass spectrometric (MS) identification (Finnigan 4000),
a 3—Ui aliquot was used. Monochlorinated normal alkanes (l—Cl- 8, l—Cl—C12,
i—Cl—C16) were added to samples for internal standards. The method was cali-
brated with tetrachiorethylene, chlorobenzenes, and aromatic hydrocarbons,
recoveries from 40 to 80 percent were measured.
14
-------
SEA
Solvent extraction analysis was used for pesticides (including PCB’s) and
non—volatile organics. Initially, GC with a packed column was used, following
procedures outlined by the EPA (5). This permitted detection of pesticides
In concentrations of 10 to 100 ng/l and above. From the beginning of October
1976 analyses were conducted with a GC system (same as above) with a glass
capillary column (20 m SE 54, Jaeggi Laboratory), and equipped with a wide—
range electron capture detector (ECD, Analog Technology Model 140). The spe-
cially designed interface consists of a temperature—stabilized hea&ing block
for preheating Argon/methane (95/5) pure gas and capillary column inlet.
One—liter composite samples were extracted with 25 ml of hexane, dried with
sodium sulfate, concentrated to 2 ml, and cleaned on a florisil column (15).
Two .il were injected splitless onto the 90°C column, and after solvent elu—
tion, the oven temperature was increased at a rate of 4°C/mm from 90°C to
230°C. This procedure allowed an improved peak separation. An internal stan-
dard, l,4—bis—(trichloromethyl)—benzene (Aldrich Chemical Co.), was added for
quantification of halogenated compounds.
VIRUSES
Virus monitoring was conducted by James N. Montgomery, Consulting Engi-
neers, Inc., Pasadena, California (3MM). The concentration methods used are
summarized in Table 4, which includes a brief description of each method, the
amount and type of chemical added, the sample volume usually tested, methods
of elution, detection limits, the location where the method was used, and the
corresponding dates. These methods were developed from a pooling of the in-
formation gathered by the San Diego County Health Department; Baylor Univer-
sity; the Los Angeles County Sanitation Districts; the University of Califor-
nia, Berkeley; the University of North Carolina, Chapel Hill; and James N.
Montgomery. The various methods were employed in an effort to improve virus
recovery and to reduce manpower requirements.
The concentration of enteric viruses in the final concentrated eluate
was determined by the plaque assay method employing either a Buffalo Green
Monkey kidney continuous cell line (BGM) maintained at JNN or a Primary Afri—
eaii Green Monkey kidney (PAG) cell line purchased commercially. The general
method consisted of adding Earle’s Balanced Salts, Fetal Calf Serum (FCS),
and antibiotics to the sample, incubating at 37°C for 90 mi diluting with
0.05M Tris Buffer, inoculating a 30— or 60—mi prescription bottle containing
the attached cell line, incubating for 90 mm at 37°C (absorption), washing
the cells with Phosphate Buffered Saline (PBS), overlaying them with agar,
and incubating at 37°C. Plaques were counted on days 2 through 7.
During the course of this study it was found that many of the apparent
plaques were not caused by animal viruses, and hence confirmation of plaques
was required in order to obtain a time count. For confirmation, cellular
debris from all suspected plaques were passed to tubes containing a monolayer
of BGM cells and maintenance media, placed on a roller apparatus, and incu-
bated for 7 to 8 days. A small sample was then passed to a new tube of the
same kind and these tubes were examined for cytopathic effects during 2 to 7
15
-------
TABLE 4. SUMMARY OF VIRUS CONCENTRATION METHODS
Adsorption or
K—27 filter
Direct
flocculation
Direct
flocculation
Adsorption ot
K—27 filter
Adsorption ot
K—27 and Cox
Filter
Adsorption ot
K—27 and Cox
Filter
lycine
H 11.5
utrienl
roth
)H 9.0
glycine
,H 11.5
utrienl
Broth
pH 9.0
Flocced, centri-
fuged, eluted up
glycine, 3 times,
last pellet dis-
solved and used
to plaque.
Same as A.
Same as A.
Flocced, centri-
fuged, eluted
twice with nutri-
ent broth, pH 9.0,
flocced atpH4.3,
dissolved at pH
9.0 and plaqued.
Same as A.
10/8/76—
11/23/76
12/3/76—
6/2/77
6/20/7 7—
7/21/ 77
12/1/75—
6/9/76
6/15/76-
7/16/ 7(
7/20/76-
7/29/7(
10/8/76-
6/2/7
6/20/ 77-
7/21/7;
Final
Detec—
Loca-
Sam-
Chem—
ample
luant
Eluant
tion
tion
)ling
icals
To lume
Tolume
Reconcentration
Volume
Limit
Sam—
Period
Meth.
Description
Added
Amount
gal
1ution
ml
— Method
ml
PFU/m 3
pled
Used
1ycine
II 11.5
I-
0• ’
11/25/75
— 7/28/7
A.
B.
C.
D.
E.
F.
Al(III) O.0005M
Acid pH 3.5
A1(III) O.003M
Al (III)
Al (III)
Al(TII) O.0005M
Acid pH 3.5
A1(III) O.005N
Acid pH 3.5
Al(III) O.0005M
Acid pH 3.5
50
1
2
2
1100
50
50
4000
200
200
500
8000
1500
1500
80
80
80
80
80
80
glycine
2xl0 2 Ql
Qi
5x10 3 Q1
5xl0 3 Ql
2 Q2
Q3
Q4
2x10 2 Q9
2x10 2 Q9
Same as A.
Same as C.
-------
days thcubation. The positives were then recorded as confirmed plaques.
Tubes determined as positive were then frozen at —70°C. All Q9 positives
were identified as were a small percentage of the positive Qi samples byJNM.
In addition, identifications were made by the California Department of Public
Health.
Virus identifications by 3MM were accomplished using the Lim—Belnish—
Melnick cross—secting antisera. A microtiter system using a cytopathic effect
(CPE) as a positive response was employed in some identifications and a plaque
reduction method was employed for others. After an initial titering of the
isolated virus, it is appropriately diluted to 100 TCID 50 /0.l ml mixed with
the cross—secting antisera, incubated one hour at room temperature, and inocu-
lated into inicrotiter dishes or plaquing bottles. Neutralization of the CPE
from a plus four to a plus one or an 80% reduction of plaques is the criteria
used for identification.
17
-------
SECTION 6
RESULTS
CHARACTERISTICS OF INFLUENT WATER
Water Factory 21 reclaims treated municipal wastewater obtained from the
Orange County Sanitation District. This wastewater has received primary and
secondary treatment by trickling filtration. The effluent characteristics as
determined from this study are given in Table 5 for the two separate periods
of operation of Water Factory 21.
TARLE 5. MEAN CHARACTERISTICS OF SECONDARY EFFLUENT
TREATED AT WATER FACTORY 21
First Period —
Second Period —
Entire Period—
Jan. 1976
Oct. 1976
Jan. 1976
through
through
through
Parameter
June 1976
June 1977
June 1977
General, mg/i
Na
209
218
212
Ca
102
110
104
Mg
25
24
25
Cl
231
258
239
SO 4
284
—
—
Alkalinity (CaCO 3 )
306
—
—
Hardness (CaCO 3 )
N11 3 —N
358
43
374
37
363
39
Org—N
1.6
8.3
5.9
P0 4 —P
5.2
5.6
5.5
B
—
1.0
—
TDS
—
1020
—
COD
108
142
131
Other
pH
7.6
7.5
7.5
EC (pS/cm)
1870
1850
1860
Turbidity (TU)
24
42
36
*
Values
18
-------
TREATMENT PLANT PERFORMANCE
Results of analysis for general inorganic and heavy metals, organics, and
viruses are given in the following paragraphs together with an evaluation of
the effectiveness of individual and combinations of processes in removing con-
stituents of interest. In general, the results are divided into the two main
periods of plant operation, that prior to October 1976 before injection was
started, and that period after October 1976 when injection was initiated.
GENERAL INORGANICS AND HEAVY METALS
Detailed summaries of data obtained for general inorganics and heavy me-
tals are tabulated in Appendix B for the period before October 1976, the pe-
riod after October 1976, and the total period. These tables contain mean
values, standard deviations (which assume normal distribution), ranges, and
numbers of samples analyzed. The following comparisons are made primarily
with mean values.
January 1976 through June 1976
A comparison of the influent, effluent and regulatory requirements for
inorganics and heavy metals for this period is given in Table 6. The results
illustrate that inorganics and heavy metals are sufficiently removed by the
advanced wastewater treatment processes to meet regulatory requirements. The
mineral quality including ammonia in general exceeded regulatory limits.
Since this was during a testing period of operation and prior to injection,
no blending, demineralization, or breakpoint chlorination for ammonia removal
was provided.
Chemical Clarification——
Lime is used as the primary coagulant in the chemical clarification pro-
cess. Lime is slaked and added as a slurry to the rapid mix basin, the water
is then flocculated in three separate individual flocculation basins, where
an anionic polymer is added to improve clarification. Lime addition is con-
trolled automatically to achieve a treatment pH of 11.3, which corresponds to
a dose of approximately 350—400 mg/l as calcium oxide. The flocculated water
is settled in the sedimentation basins, which are equipped with settling tubes.
Chemical clarification is effective in reducing turbidity, COD and phosphate
concentrations. Operation of the chemical clarifier at pH of 11.3 or greater
provides good removal efficiency. A monthly and period summary for some of
the parameters monitored on a continuous basis is given in Table 7. Chemical
clarification was also effective in reducing many of the heavy metals remain-
ing in the secondary effluent. Lime treatment reduced arsenic, barium, cad-
mium, Cr(VI), copper, iron, lead, manganese, silver, and zinc concentrations.
The percentage removal for each metal is summarized in Table 8. Those metals
which were not reduced by chemical treatment were mercury and selenium.
Ammonia Stripping——
The effluent from the chemical clarifier had an average pH of 11.4 and
was pumped to the top of the ammonia stripping towers. Tower No. 1 was op-
erated until May 1, 1976, at full design capacity of 2.7 m 3 /rn 2 —h of packing
19
-------
TABLE 6. hEAR CHARACTERISTICS OF TREATED WATER AND REGULATORY REQUIRE}IENTS
January 1976 through June 1976
Regulatory
Chlorine
Require—
for
Ammonia
Contact
Overall
ment
Plant
Clarif.
Tower
Filter
Carbor
Basin
Reduc—
Blended
Param—
Infi.
El flu
Effi.
Effl.
Effi.
El 11.
tion
Injection
eter
Inits
Q1_
O2
Q4
Q6
Q8
Q9
Percent
Alk tg/i 306 328 — — 137 55 —
N11 3 —N g/l — 43 19 — 17 60 1.0
TKN g/1 — 44 — 0.5 0.9 96 1.0
B ig/l — — — 0.63 — 0.5
Ca ig/1 102 142 107 — —
Cl ig/l 231 — 246 — 120
EC iS/cm 1870 — 1470 21 900
F g/1 — — 0.64 — 0.8
Mg ag/i 25 1.0 — 96 —
pH 7.6 11.4 6.7 — 6.5—8.0
P0 4 —P ag/i 5.2 0.09 — 98 —
Na ag/i 209 — 205 — 110
S04 ag/i 284 — 312 125
TH ig/i 358 359 — 271 — 220
Turb. ‘U 24 1.9 0.5 0.9 96 1.0
CN tg/l — — — — — — 200
COD ig/k 108 53 45 13 88 30*
As tg/1 2.5 1.1 1.1 1.1 56 50
Ba Lg/1 81 41 32 33 59 1000
Cd ig/l 9 2.9 2.5 2.2 76 10
Cr ig/1 192 88 84 48 75 50
Cu ig/1 285 93 88 27 91 1000
Fe ig/l 179 17 40 45 75 300
Pb ig/i 40 23 22 26 35 50
Mn ig/1 38 1.5 2.3 4.1 89 50
Hg ig/i 1.2 0.9 1.2 4.9 0 5
Se ig/1 6.2 6.5 6.3 6.4 0 10
Ag ig/1 13 8 12 14 — 0 50
Zn ig/i 300 29 670 124 — 59 —
Gross ctCi/1 — — — — 0.3 —
Gross B pCi/i 28 —
E.co li <2.0 <2.0
*Regtllatory requirement for effluent COD pertains to carbon effluent (Q8).
area, corresponding to a 3000 1n 3 /m 3 air to water ratio at ambient air temper-
atures. During this period, however, it was observed that significant air
short circuiting occurred within the tower. Therefore, it is believed that
the actual air to water ratios were only about 700 to 1500 m 3 /m 3 . From
January through April, the average ammonia removal was only 54 percent.
20
-------
TABLE 7. CHANGES IN GENERAL PARAMETERS BY CHEMICAL CLARIFICATION
January through June 1976 (Monthly Mean Values)
Parameter
Units
Jan
Feb
Mar
Apr
May
June
Avg.
COD
Inf., Qi
mg/i
—
113
101
96
107
120
107
Eff., Q2
mg/i
—
54
51
47
51
59
52
Reduct.
%
—
52
50
51
52
51
51
P0 4 —P
Inf., Qi
mg/i
5.7
5.9
4.9
5.8
4.3
4.7
5.2
Eff., Q2
mg/i
0.05
0.08
0.17
0.02
0.05
0.16
0.09
Reduct.
%
99
99
97
100
99
97
98
Turbidity
Inf., Qi
mg/i
21
23
22
17
25
33
24
Eff., Q2
mg/i
1.3
2.3
1.5
1.6
1.7
2.2
1.8
Reduct.
%
94
90
93
91
93
93
92
pH
Inf., Qi
units
7.6
7.7
7.7
7.7
7.7
7.6
7.7
Eff., Q2
units
11.5
11.4
11.4
11.4
11.3
11.3
11.4
Magnes iuni
Inf., Qi
mg/i
26
26
24
24
24
—
25
Eff., Q2
mg/i
2.0
1.1
1.3
0.8
0.7
1.2
Reduct.
%
92
96
95
97
97
—
95
Calcium
Inf., Qi
mg/i
L09
94
iii
105
106
98
104
Eff., Q2
mg/i
135
141
162
151
129
138
143
Increase
Z
24
50
46
44
22
41
38
TABLE 8. CHEMICAL CLARIFICATION. HEAVY METALS REMOVAL
January through June 1976
Parameter
Units
Plant
Influent
Qi
Clarifier
Effluent
Q2
Percent
Removed
As
ugh
2.5
1.1
56
Ba
uig/1
81
41
49
Cd
uig/l
9
2.9
68
Cr
ig/l
192
88
54
Cu
g/l
285
93
67
Fe
ulg/i
179
17
91
Pb
g/l
40
23
43
Mn
g/l
38
1.5
96
Hg
ag/i
1.2
0.9
25
Se
j ig/i
6.2
6.5
no
change
Ag
pg/l
13
8
38
Zn
jig/i —
300
29
90
21
-------
Ammonia tower No. 2 was modified to reduce short circuiting and was
placed in operation about Nay 1, 1976. During May and June ammonia removal
increased to 63 percent as indicated in Table 9. Aimnonia—nitrogen influent
concentrations varied from a high of 100 mg/i during May to a low of 27 mg/i
during January, with a mean of 43 mg/i. Effluent ammonia—nitrogen concentra-
tions averaged 18 mg/l during the entire six months. Since the water being
treated at this time was not injected, no further nitrogen control was prac-
ticed prior to October, 1976.
Recarbonation——
Recarbonation was achievedby diffusing carbon dioxide gas into the flow
in two stages with allowance for intermediate settling. The first stage re-
duced pH between 9.5 and 10.3. Following intermediate settling, additional
CO 2 was added in the second stage to reduce pH to about 7.0. The cool and
compressed stack gases from the lime recalcining furnace provided the source
of CO 2 . The purpose of two—stage recarbonation is to remove as much calcium
as possible and thus reduce TDS. However, during actual operation the calcium
carbonate fioc which precipitated in the intermediate settling basin was very
fine and difficult to settle and so the performance of the recarbonation basin
for removing TDS and calcium was poor.
Mixed—Media Filtration——
Following pH adjustment in the recarbonation basin, the wastewater flows
into open gravity—flow multimedia filters. Enhancement of turbidity removal
is accomplished by the addition of alum (12 mg/i) and Dow A23 anionic polymer
(0.05 mg/i). Typical filter runs averaged 20—22 hours at a mean effluent
turbidity of 0.5 TU.
Activated—Carbon Adsorption——
The activated—carbon adsorption process follows mixed—media filtration.
The plant design includes 17 parallel carbon contactors, 16 can be operated
in parallel, with one remaining unit available for carbon storage. Columns
No. 3, 4, and 5 were used primarily during this period of operation. Results
TABLE 9. AMMONIA REMOVAL BY STRIPPING
January Through June 1976
Month
Stripping
Tower
Number
Mean NH3—N, mg/i
Percent
Removal
Influent
Q2
Effluent
Q4
January
February
March
April
May
June
Average
1
1
1
1
2
2
38
49
45
43
44
38
43
18
22
21
18
16
14
18
53
55
53
58
64
63
58
22
-------
on organic removals by activated carbon are given later. Activated, carbon
was effective in reducing the concentration of cadmium, chromium, copper, and
zinc as listed in Table 10. The data also show that activated—carbon treat-
ment resulted in significant increases in iron and manganese concentrations,
although the resulting concentrations were below regulatory limits and re-
sulted in no adverse effect. Data also show that activated—carbon treatment
had little effect on arsenic, barium, lead, mercury, selenium, and silver at
the low concentrations which were present in the influent.
October 1976 through June 1977
During this period, breakpoint chlorination was Initiated to reduce the
ammonia concentration to meet requirements for injection., One part of treated
water was then blended with two parts of well water from a deep aquifer in
order to reduce the mineral content as required by regulations. Injection of
blended water was Initiated during this period. In addition, pilot studies
were started with reverse osmosis treatment of reclaimed wastewater as an al-
ternative method for reducing the mineral content to an acceptable level.
A summary of water quality at different points in the treatment system
and a comparison with the regulatory requirements is given in Table 11. Each
volume of Water Factory 21 effluent is blended with two volumes of water ob-
tained from deep wells to form blended injection water (QlO). The quality of
this blended water is compared in Table 11 with the quality requirements for
injection water as issued by the California State Water Quality Control Board
——Santa Ana Region. The regulatory limit of 1 mg/i of ammonia is presently
under question. In addition, the need for demineralization is apparent and
it is anticipated that with the completion of a new 0.22 m 3 /s RO plant, the
overall reduction in EC required will be met in the future without the need
to blend with groundwater.
TABLE 10. HEAVY METALS REMOVAL BY CARBON ADSORPTION
January through June 1976
Parameter
Units
Carbon
Influ
Q6
Col
ent
Carbon
Ef flue
Q8
Col
nt
Percent
Removal
As
iig/l
1.1
1.1
no change
Ba
pg/i
32
33
no change
Cd
pg/l
2.5
2.2
12
Cr
pg/l
84
48
43
Cu
pg/l
88
27
69
Fe
pg/i
40
45
increase
Pb
pg/i
22
26
no change
Mn
pg/l
2.3
4.1
increase
Hg
pg/i
1.2
4.9
increase
Se
pg/i
6.3
6.4
no change
Ag
pg/i
12
14
no change
Zn
pg/i
670
124
81
23
-------
TABLE 11. MEAN CHARACTERISTICS OF TREATED WATER AND REGULATORY REQUIREMENTS
October 1976 through June 1977
Blended Injection
Plant
Clarif.
Recarb.
Filter
Carbon
eduction
Water
Mean
Regulatory
Param—
Infi.
Effi.
Effi.
Effi.
Effi.
Qi to Q8
Conc.
Require—
eter
Units
Qi
Q2
Q5
Q6
Q8
Percent
Ql0
metit
Aik mg/i — — 116 — 121 —
NR 3 _N* mg/i 45 37 — 3.3 93 0.9 1.0
NOD—N mg/i - - — - 1.0 -
Org—N mg/i — - — - 0.7 —
TKN mg/i 53 41 4.6 91 1.6 10
B mg/i 1.0 0.84 — — — 0.36 0.5
Ca mg/i 110 0 103 37 —
Ci mg/i 258 — — 103 120
E Coil MPN/ 41x 106 16 < 2 < 2
100 mJ
EC PS/cm 1850 2070 780 900
F mg/i — — 0.53 0.8
Mg mg/i 24 0.2 — 0.6 —
pH 7.5 11.5 8.1 7.6 6.5—8.0
P0 4 —P mg/i 5.6 0.07 — — —
Na mg/i 218 — — 127 110
SO 4 mg/i — — — — — 83 125
TH mg/i — — — — — 99 220
Turb. TU 42 .1.1 1.2 0.34 — — 0.42 1.0
COD mg/i 142 52 — 45 18 87 11 30**
TOC mg/i — — — 14 6.7 — — —
MBAS mg/i — — — — — — 0.05 0.5
As pg/i 3.3 2.5 — 1.8 2.4 27 2.6 50
Ba pg/i 81 36 — 31 31 62 14 1000
Cd pg/i 29 2.4 — 1.8 1.7 94 0.6 10
Cr pg/i 154 37 — 41 26 83 8.8 50
Cu pg/i 266 73 — 49 32 88 12 1000
Fe pg/i 325 40 — 207 66 80 71 300
Pb Pg/i 19 3.6 4.7 5.3 72 2.8 50
Mn Pg/i 35 4.4 6.2 4.9 86 4.6 50
Hg pg/i 9 2.6 3.6 6.7 26 2.4 5
Se pg/i <2.5 <2.5 <2.5 <2.5 — 1.8 10
Ag Pg/i 5.5 0.8 1.3 1.5 73 0.8 50
Zn Pg/i 380 239 412 162 57 160 —
CN Pg/i — — — — — <0.01 200
Phejxl Pg/i — 1.3 —
*
Ammonia tower effluent (Q4) = 6.5.
**
COD of 30 mg/i appiie to carbon effluent (Q8).
24
-------
Chemical Clarification-—
The general performance of the chemical clarifier during the second pe-
riod is given in Table 12. Chemical clarification continued to be effective
for reducing COD, turbidity, phosphate, and magnesium when operated at pH val-
ues of greater than 11.3. Chemical clarification also reduced several heavy
metals concentrations as indicated by the summary in Table 13. The metals
removed include barium, cadmium, chromium, copper, iron, lead, manganese,
silver, and zinc.
Ammonia Stripping——
During the operational period prior to October 1976, ammonia removal ef-
ficiencies had averaged a maximum of 65 percent. In an attempt to improve the
efficiency of this operation, the ammonia towers were modified during the
plant shutdown and repiped so that two towers could be operated in series.
The effect of this modification on the performance of ammonia stripping is
indicated in Table 14. Overall performance was increased to achieve over 80
percent removal of ammonia nitrogen. During the summer months, ammonia nitro-
gen removals exceeded 90 percent. The first stripping tower reduced ammonia
concentrations from an average of 32 mg/i to 11.2 mg/i, for a reduction of
65 percent. The second tower then further reduced this concentration to a
mean average of 5.7 mg/l or by an additional 49 percent. Influent ammonia
nitrogen concentrations ranged from a high of 85 mg/i in November to a low of
13 mg/i during January.
Recarbonation and Breakpoint Chlorination——
Since two—stage recarbonation had proven to be difficult to operate dur-
ing the first evaluation period, it was decided to operate the recarbonation
basin as a single—stage system. Thus sufficient carbon dioxide was added to
reduce the pH from 11.3 to a range between 7.5 and 8.0. Since the residual
ammonia remaining after stripping still exceeded the injection requirements,
the District also began breakpoint chlorination in October. Large quantities
of chlorine were required (9:1 chlorine to ammonia ratio) which reduced the
pH. In order to prevent excessive pH decrease it was found desirable to use
breakpoint chlorination in conjunction with recarbonation. At this point
chlorination reduced the quantity of CO 2 needed for pH reduction and pH con-
trol was easier. Addition of chlorine in the recarbonation basin provided
sufficient contact time for ammonia oxidation and resulted in a reduction of
ammonia nitrogen from an average of 5.7 mg/i to less than 1 mg/i, as well as
reducing pH to an average of 8.3.
As discussed in a subsequent section on organics, breakpoint chlorina-
tion had an undesirable effect in that it resulted in the production of
chlorinated organics, particularly various haloforms, and these were only
partially removed by activated—carbon adsorption. For this reason, break-
point chlorination at the recarbonation basins was discontinued in April 1977
and was attempted with effluent from the activated—carbon contactors. Here,
pH control proved difficult and ammonia removal was less efficient.
The requirement for 1 mg/l maximum ammonia nitrogen in the injection
water has been questioned by the OCWD and they have appealed to have the
limit raised. Some removal of ammonia through ion exchange is expected as
the injected water moves through the aquifer. Also, the high costs for
25
-------
TABLE 12. CHANGES IN GENERAL PARM1ETERS BY CHEMICAL CLARIFICATION
October 1976 through June 1977 (Monthly Mean Values)
Parameter
Units
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
May
June
Avg.
COD
Inf., Qi mg/i 142 138 142 127 130 122 130 122 208 142
Eff., Q2 mg/i 56 49 51 46 48 44 46 48 72 52
Reduct. 61 64 64 64 63 64 65 61 65 63
PO 4 —P
Inf., Qi mg/i 5.9 5.3 6.0 6.1 5.9 5.5 5.1 5.5 5.2 5.6
Eff., Q2 mg/i 0.12 0.03 0.10 0.10 0.08 0.05 0.05 0.06 0.05 0.07
Reduct. 98 99 98 98 99 99 99 99 99 99
turbidity
m l., Qi TU 26 33 49 41 44 41 35 53 42
Eff., Q2 TU 1.3 1.1 1.3 0.9 1.1 1.3 1.2 1.0 1.1
Reduct. 95 97 97 98 98 97 97 98 97
pH
ml., Qi pH 7.6 7.6 7.5 7.5 7.5 7.6 7.6 7.3 7.4 7.5
Elf., Q2 pH 11.3 11.6 11.6 11.5 11.5 11.5 11.4 11.4 11.6 11.5
Magnesium
Inf., Qi mg/i 22 22 22 22 24 24 24 26 27 24
Elf., Q2 mg/i 0.3 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.2 0.2
Reduct. 98.6 99.6 99.6 99.6 99.2 99.2 99.2 98.9 99.3 99.2
-------
TABLE 13. EFFECT OF CHEMICAL TREATMENT ON HEAVY METALS
October 1976 through June 1977
Heavy
Metal
Clarifier
Influent
(Ql), pg/l
Clarifier
Effluent
(Q2),pg/l
Percent
Removal
As
3.3
2.5
24
Ba
81
36
56
Cd
29
2.4
92
Cr
154
37
76
Cu
266
73
73
Fe
325
40
88
Pb
19
3.6
81
Mn
35
4.4
87
Hg
9
2.6
71
Se
<2.5
<2.5
—
Ag
5.5
0.8
85
Zn
380
239
37
TABLE 14. EFFECTIVENESS OF AMMONIA STRIPPING PROCESS
October 1976 through June 1977
Month
October
November
December
January
February
March
April
May
June
Mean NH 3 —N conc., mg/i
Influent Effluent
(Q2) (Q4)
34 5.7
33 4.9
30 5.4
24 6.0
37 5.5
36 7.6
41 8.7
37 7.5
46 6.5
Percent
Removal
83
85
82
75
85
79
79
80
86
Average
35
6.4
82
breakpoint chlorination, the increased concentrations of chlorinated organics
which result, and the potential decrease in activated—carbon adsorption have
made the OCWD question whether the benefits of the low ammonia requirements
are worth the costs.
Filtration——
Following single—stage recarbonation, the water receives mixed—media
filtration prior to activated—carbon adsorption. Again, alum (12 mg/i) and
Dow A23 anionic polymer (0.05 mg/l) were added to improve turbidity removal.
Typical filter runs were 20—30 hours, with a mean filter run of 26 hours, re-
sulting in an average effluent turbidity of 0.28 TU. Table 15 summarizes
27
-------
TABLE 15. FILTER PERFORMANCE FOR TURBIDITY REDUCTION
October 1976 through June 1977
Month
Mean Turbidity, TU
Percent
Removal
Influent
(Q5)
Effluent
(Q6)
October
November
December
January
February
March
April
Nay
June
Average
6.7
1.4
1.4
0.90
1.2
1.1
1.1
1.3
1.4
1.8
0.72
0.31
0.24
0.18
0.24
0.34
0.3
0.5
0.4
0.36
89
79
83
80
80
69
73
62
71
80
filter performance for the second period of plant operation. These data dem-
onstrate the consistent performance of the mixed—media filters and their abil-
ity to produce water with turbidities below 1 TU as required by State regula—
tions.
Activated—Carbon Adsorption——
During the second period the activated—carbon columns were operated in a
packed—bed upflow configuration, with a 30—minute contact time. Overall per-
formance of the granular activated—carbon system was good. Ability to remove
organics is summarized later under organics.
Activated—carbon treatment was also effective in reducing several heavy
metals as summarized in Table 16. Chromium, copper, iron, lead and zinc were
reduced in concentration, and all other metals exhibited essentially no change
or a slight increase In concentration. However, effluent concentrations of all
heavy metals are sufficiently low to meet U.S. EPA drinking water standards.
Chlorination——
Following activated—carbon treatment, the water flows by gravity to the
chlorine contact basin, primarily for post—chlorination to destroy any bac-
teria or virus. Prior to April 1977 breakpoint chlorination was practiced at
the recarbonation basin and post—chlorination required only a small chlorine
dose of 2—5 mg/i to insure complete disinfection and removal of bacteria and
virus as discussed later under VIRUS.
ORGANICS
COD and TOC
The COD analysis gives a general measurement of the total concentration
28
-------
TABLE 16. HEAVY METALS REMOVAL BY ACTIVATED CARBON
October 1976 through June 1977
Heavy
Metal
Mean Concentration, ilg/l
Percent
Removal
Influent
(Q6)
Effluent
(Q8)
As
Ba
Cd
Cr
Cu
Fe
Pb
Mn
Hg
Se
Ag
Zn
1.8
31
1.8
41
49
207
4.7
6.2
3.6
<2.5
1.3
412
2.4
31
1.7
26
32
66
5.3
4.9
6.7
<2.5
1.5
162
increase
0
6
37
35
68
increase
21
increase
—
increase
61
of organics present in a water in terms of the quantity of oxygen which would
be required for oxidation to carbon dioxide, water and ammonia. Results of
COD analysis on composite samples taken at various locations at Water Factory
21 during the first and second periods of operation, and over the entire pe-
riod are summarized in Table 17. Influent COD and plant performance in the
removal of COD were similar during the two periods. Influent COD averaged
131 mg/l, and this was reduced by 60 percent to 52 mg/i by chemical treatment.
This only partly resulted from removal of suspended organics. The filter
effluent contained 45 mg/l COD, and this was reduced 67 percent to 15 mg/i by
passage through activated carbon, which was particularly effective for dis-
solved organics. Water Factory 21 overall removed 90 percent of the influent
organics.
TOC is also a general parameter for total organics. The mean influent
(Q6) and effluent (Q8) concentrations for activated carbon adsorption listed
in Table 18 indicate this process removed approximately 49 percent of the or-
ganic carbon passing through it, which is somewhat less than for COD reii val.
Perhaps activated carbon is more selective in the removal of reduced organics
having a higher COD to TOC ratio.
The coefficient of variation (100 standard deviation/mean) for effluent
COD was 53 percent and for TOC was 35 percent. These values are quite small
and indicate that the treatment systems produce an effluent which is rela-
tively consistent in general organic content.
Volatile Organic Analysis
This analysis was conducted on grab samples obtained periodically since
February 1976. Concentrations of the two major haloforins found during the
first period before breakpoint chlorination was initiated are indicated in
29
-------
TABLE 17. COD REMOVAL BY WATER FACTORY 21
Sampling Period
and
Characteristic
Plant
Influeni
Ql
Chem.Treat.
Effluent
Q2
Filter
Effluent
Q6
ict.Carb.
ff1uent
Q8
RO
Influent
Q21A
RO
Effluent
Q21B
Jan. through June
1976
Mean, mg/i
108
53
45
13
Std. dev.,mg/1
16
7
7
8
Range, mg/i
78—14/
23—69
25—67
2—52
No. samples
78
80
87
238
Oct. 1976 through
June 1977
Mean, mg/i
142
52
45
18
24
1.8
Std. dev.,mg/i
37
11
7
7
14
1.5
Range, mg/i
89—27:
20—109
31—78
4—51
4—69
<1—9
No. samples
160
160
160
159
118
119
Total Period, Jan.
1976 through June
1977
Mean, mg/i
Std. dev.,mg/i
131
35
52
10
45
7
15
8
Range, mg/i
78—27
20—109
25—78
2—52
No. samples
238
240
247
397
TABLE 18. TOC REMOVAL BY WATER FACTORY 21
Sampling Period
Activated Carbon
Activated Carbon
and
Influent
Effluent
Characteristic
Q6
Q8
January through June 1976
Mean, mg/i
15
7.3
Std. dev., mg/i
4
2.6
Range, mg/i
8—31
3.5—20
No. samples
82
238
October 1976 through June 1977
Mean, mg/i
14
6.7
Std. dev., mg/i
3
2.2
Range, mg/i
0.5—28
2.5-14
No. samples
111
117
Total Period, January 1976
through June 1977
Mean, mg/i
14
7.1
Std. dev., mg/i
3
2.5
Range, mg/i
0.5—31
2.5—20
No. samples
193
355
30
-------
Table 19. Influent concentrations were low and were decreased even further
through ammonia stripping. Lime treatment had essentially no effect on halo—
form concentration. Chlorination for disinfection only (< 10 mg/i Cl 2 ) after
activated—carbon treatment appears to have increased the concentration of
chloroform (CHC1 3 ) and broxnodichloromethane (CHBrC1 9 ) slightly.
Following the initiation of breakpoint chlorination in October 1976, con-
centrations of the various haloforins increased significantly during treatment
(Table 20). Breakpoint chlorination generally followed ammonia stripping and
maximum concentrations of haloforms were noted in samples taken prior to
activated—carbon contacting. Activated—carbon treatment was responsible for
a reduction in haloform levels.
These results are better illustrated in Figure 3 showing haloform concen-
trations for the influent to the carbon contactors and for the final effluent.
Haloform formation was variable. For the first month, chlorine dosages var-
ied widely as did haloform concentration while seeking good operational pro-
cedures. After this period, however, haloform concentrations still varied
considerably. For a few days in December, breakpoint chlorination was prac-
ticed in the final chlorine contact chamber rather than after ammonia strip-
ping, and resulted In a decrease in haloforms at point Q6. From April through
June chlorination for ammonia removal was practiced at Q8 only, resulting in
a significant reduction in haloforms at Q6.
Figure 3 illustrates that the haloform concentration in the final ef flu-
ent was less variable and lower than in samples taken before activated—carbon
treatment. Of particular significance is the decrease in effluent haloform
concentration during December which resulted when the flow was diverted
to carbon contactors containing fresh activated carbon. Haloforms soon began
passing through the contactors, but at significantly reduced concentrations.
TABLE 19. HALOFOR}f CONCENTRATIONS PRIOR TO BREAKPOINT CHLORINATION
January 1976 through June 1976
Characteristic
Sampling Location
Influen
Ql
Act.—Carb
Influent
Q6
Act.—Carb.
Effluent
Q8
Final
Effluent
Q9
CUC1 3
Mean, pg/l
Standard deviation, pg/i
Range, pg/l
Number of samples
CHBrC1 2
Mean, pg/i
Standard deviation, pg/l
Range, pg/i
Number of samples
1.5
1.0
0.4—5.5
39
0.2
0.3
0.0—1.2
14
0.3
0.2
0.1—0.6
4
0.0
0.0
0.0
4
0.6
0.4
0.4—1.0
3
0.1
0.2
0.0—0.3
3
2.1
1.1
0.6—5.3
40
0.9
1.0
O.03.9
40
31
-------
TABLE 20. HALOFORN CONCENTRATIONS DURING SECOND PERIOD
October 1976 through June 1977
Sample Location
Ammonia
Activ.-
Contact
Clarif.
Tower
Filter
Carbon
Basin
RO
RO
Influent
Effluent
Effluent
Effluent
Effluent
Effluent
Influent
Effluent
Ql
Q2
Q4
Q6
Q8
Q9
Q21A
Q2 IB
CHO1 3
Mean, pg/i 2.5 1.2 0.2 19 9.3 10 5.5 9.6
Std. Dev,, pg/i 6.1 0.7 0.1 22 8.5 8.4 8.1 10.5
Range, pg/i 0.2—39 0.4—2.3 0.1—0.5 0.1—97 0.3—36 0.8—40 0.1—21 0.1—35
No. of Samples 40 ii 32 36 39 40 6 16
CHBrC1 2
Mean, pg/l 0.24 0.4 0.03 8.8 2.1 3.6 4.6 5.7
Std. Dev., pg/l 0.22 0 .6 0.1 70 2.4 3.0 9.1 8.0
Range, pg/i 0—1.1 0—1.4 0—0.2 0—32 Tr—l0 0.2—14.0 0—23 Tr—22
No. of Samples 26 9 20 38 39 40 6 16
CHBr 2 C1
Mean, pg/i 2.2 0.1 0.06 4.0 0.6 2.0 1.8 22
Std. Dev. , pg/l 3.2 0.3 0.10 5.0 0.9 2.3 3.4 4.6
Range, pg/i 0—10.0 0—0.7 0—0.3 0—18.0 0—3.5 0—10 0—7.9 0—17
No. of Samples 20 9 10 33 31 38 6 15
CHBr 3
Mean, pg/i 0.5 0 0 1.8 0.2 0.4 O.i 0.5
Std. Dev. ,pg/1 1.0 0 0 5.1 0.5 0.6 0.2 1.0
Range, pg/i 0—2.9 0 0 0—23 0—2.3 O—i.8 0—0.4 0—2.8
No. of Samples 14 5 9 23 23 26 3 10
-------
Figure 3.
0’
I —
z
w
0
z
0
0
z
0
I —
z
I i i
0
z
0
C.)
Haloform concentrations at filtration effluent and activated—carbon effluent during second
period of operation (October 1976 through June 1977).
DAY OF OPERATION
-------
During periods when breakpoint chlorination was changed to point Q8, the ef-
fluent haloform concentration did not increase above the previous effluent
level, suggesting perhaps that the major organic precursors of the haloforins
were effectively removed by carbon contacting. However, the required 9:1 ra-
tio of chlorine to ammonia could not be maintained at Q8 due to pH problems
and this may have reduced the potential for haloform formation also. Some
haloforms were formed as can be seen by a comparison of Q6 and Q9 concentra-
tions after April 1977 (Figure 3).
The VOA analysis allows measurement for chlorinated compounds other than
haloforms as listed in Table 21 for the period since October 1976. The chrom-
atographic peaks for l,l,l—trichloroethane and carbon tetrachloride coincided
so that differentiation between these compounds was not possible. However,
the presence of l,1,l—trichloroethane, but not carbon tetrachioride, was veri-
fied by GC/MS. Because insufficient samples were analyzed, it is difficult to
draw firm conclusions.
The data in Table 21 do illustrate the effectiveness of ammonia strip-
ping in removal of volatile compounds (compare Q4 with Q2 values). No other
process at Water Factory 21, including activated—carbon contacting, was gen-
erally as effective in the removal of these materials, although each process
played a part in the overall removals obtained.
Closed—Loop Stripping Analysis
Samples taken between 1/19/77 and 6/12/77 and from various stages of the
treatment were extracted and analyzed. On 9 sampling dates complete sets of
samples (Ql, Q2, Q4, Q6, Q 8 , Q9) were taken, and on 4 sampling dates only the
chlorinated effluent and the reverse osmosis plant effluent were sampled. In
Ql, the load of organics was often too high and results were not reliable.
Eight of the most prominent substances of health significance (ethylben—
zene; chlorobenzene/o—xylene; 1, 3—,l ,4—, and 1 ,2—dichlorobenzene; 1,2, 4—tn—
chlorobenzene and naphthalene) were selected as indicators for the efficiency
of the various treatment processes. Mean values, standard deviation, range,
and numbef of samples are given in Table 22. Average concentrations in Ql
vary from 210 ng/l for l,2,4—trichlorobenzene to 2000 ng/1 for 1,4— and 1,2—
dichlorobenzenes. Individual measurements vary more than one hundred percent
and the standard deviations in some cases are larger than the mean value.
Therefore direct comparisons of the mean values are difficult.
A better picture of the effect of the treatment is obtained by averaging
the change of the paired values (values obtained from samples taken at the
same time). For the 2 processes which are effective In removing volatile
trace organics (ammonia stripping, and activated—carbon treatment) these
values are included in Table 23. All selected trace contaminants showed an
average removal of more than 60 percent during ammonia stripping with the ex-
ception of naphthalene (40 percent) and 1,2,4—trichlorobenzene (50 percent).
In a few cases, an apparent increase in the concentration was measured which
probably was caused by variations in the influent concentrations. The effec-
tiveness of ammonia stripping in removing this broad range of organic
34
-------
TABLE 21. CONCENTRATIONS OF HIGHLY VOLATILE CONSTITUENTS OTHER THAN HALOFORMS (ugh)
October 1976 through June 1977
(J
U I
Sample Location
Influent
Qi
Clarif.
Effluent
Q2
Ammonia
Tower
Effluent
Q4
Filter
Effluent
Q6
Activ.—
Carbon
Effluent
Q8
Contact
Basin
Effluent
Q9
RO
Influent
Q21A
RO
Effluent
Q21B
CH 2 C1 2
Mean
Std. Dev.
Range
No. of Samples
C1 3 C—CH 3 ICC1 4
Mean
Std. Dev.
Range
No. of Samples
C1 2 C = CHC1
Mean
Std. Dev.
Range
No. of Samples
CC12 CC1 2
Mean
Std. Dev.
Range
No. of Samples
24
20
1.7—74
40
6.3
4.7
0—24
37
1.5
1.5
0—39
33
1.3
3.0
0—15
24
6.2
7.1
0.9—12
11
3.9
9.1
0—28
11
0.7
0.9
0—2.4
10
0.4
0.4
0—1.0
9
2.7
3.1
Tr.—12
32
0.2
0.6
0—2.5
28
0.1
0.3
0—1.4
27
0.03
0.07
0—0.2
12
3.3
4.1
0.1—18
38
0.08
0.2
0—1.2
36
0.1
0.4
0—2.4
33
0.3
0.6
0—20
33
2.6
8.9
0.2—12
38
0.08
0.2
0—1.0
34
0.03
0.06
0—0.2
33
0.1
0.3
0—0.9
31
3.4
5.6
0.2—33
40
0.1
0.3
0—1.2
37
0.04
0.1
0—0.3
34
0.1
0.3
0—0.9
38
0.8
0.4
0.4—1.5
6
0
0
O—Tr.
6
Tr.
Tr.
O—Tr.
6
Tr.
Tr.
0—0.1
6
1.4
1.6
0.2—6.2
16
0.03
0.08
0—0.3
16
0.03
0.06
H0.O2
15
0.04
0.07
0—0.2
14
Tr less than 0.05
-------
TABLE 22. CLOSED—LOOP STRIPPING ANALYSES FOR SELECTED ORGANICS (ng/1)
October 1976 through June 1977
Sample Location
Influent
Ql
Clarif.
Effluent
Q2
Ammonia
Tower
Effluent
Q4
Filter
Effluent
Q6
Activ.—
Carbon
Effluent
Q8
Contact
Basin
Effluent
Q9
RO
Effluent
Q21B
Ethyl benzene
Mean 1300 310 70 60 30 40 35
Std. Dev. ± 910 260 60 20 20 50 20
Range 230—1900 110—880 10—170 30—100 Tr.—50 Tr.—180 Tr.—60
No. of Samples 3 7 8 8 7 16 6
Chlorobz /O—Xylene
Mean 900 540 130 100 50 70 90
Std. Dev. 540 490 80 60 50 90 65
Range 200—1300 130—1700 25—240 30—210 Tr.-130 Tr.—370 Tr.—150
No. of Samples 4 8 8 8 5 16 6
1, 3—Dichlorobenzene
Mean 300 130 30 30 5 140 16
Std. Dev. 310 170 30 60 10 180 20
Range 60—840 15—530 0—60 0—160 0—20 0—500 0—40
No. of Samples 5 8 8 8 8 14 5
1, 4—Dichlorobenzene
Mean 2000 800 50 30 20 15 20
Std. Dev. 1790 540 40 10 20 10 30
Range 600—4900 130—1900 Tr.—120 Tr.—40 0—50 Tr.—30 0—60
No. of Samples 5 8 7 7 8 14 5
1, 2—Djchlorobenzene
Mean 2000 1100 340 300 60 100 70
Std. Dev. 1560 1070 320 450 50 80 70
Range 600—4700 40—3200 Tr.—750 10—1200 0—130 Tr.—320 Tr.—200
No. of Samples 5 8 8 8 7 15 6
Table 22 continued
-------
TABLE 22 (cOntinued)
( )
Sample Location
Influent
Ql
Clarif.
Effluent
Q2
Ammonia
Tower
Effluent
Q4
Filter
Effluent
Q6
Activ.—
Carbon
Effluent
Q8
Contact
Basin
Effluent
Q9
RO
Effluent
Q21B
l,2,4—Trichlorobenzer
Mean
Std. Dev.
Range
No. of Samples
Naphthalene
Mean
Std. Dev.
Range
No. of Samples
210
270
Tr.—520
4
220
130
130—410
4
190
170
0—510
8
530
380
90—940
7
70
70
0—160
8
180
160
40—500
8
20
50
0—110
8
110
100
0—230
8
10
10
0—20
8
40
40
0—100
8
120
190
0—500
16
30
30
0—80
14
60
80
0—120
6
20
10
Tr.—40
6
Tr 20 ng/1.
-------
volatiles is not surprising since the enrichment procedure in the analytical
test is similar to the ammonia—stripping process.
The effectiveness of the activated—carbon treatment can be seen from the
averaged relative removals calculated from the paired values Q6 and Q8 in
Table 23. The data indicate an average removal of more than 50 percent for
all of the selected compounds. Again in a few cases, the concentration of the
effluent was found to be higher than the corresponding concentration of the
influent, thus causing a big variation in the averaged removal. For the other
processes, an interpretation of removal efficiency is more difficult. Lime
clarification (Ql, Q2) reduced concentrations in all cases except for naph—
thalene (Table 22). The Influent water contained particulate as well as sol-
uble organic matter, and this made quantification unreliable; therefore no
valid data on removal efficiency can be given for this process at this time.
Recarbonation and filtration (Q4, Q6) do not affect the concentration of
the volatile compounds significantly. Also, for the reverse osmosis (RO) pro-
cess, rio significant removal effect could be found. The RO effluent (Q21B)
samples showed approximately the same mean concentrations as the chlorination
effluent (Q9). The same was found for the haloforms (Table 20). However, RO
was quite effective in overall COD removal (Table 17). Thus, many organics
are removed by RO, but not the more volatile and low molecular weight sub-
stances measured by VOA and CLSA. Removal of volatiles by the overall plant
TABLE 23. EFFICIENCY OF AMMONIA STRIPPING AND CARBON ADSORPTION FOR
REMOVAL OF SELECTED TRACE ORGANICS BASED UPON PAIRED SAMPLES
Process
Ammonia
Stripping
Carbon
Adsorption
‘
No. of
Paired
i amp±es
Percent Removal
No. of
Paired
Samples
Percent Removal
Mean
Std.
Dev.
Mean
Std. —
Dev.
Ethy lbenzene
Chlorobenzene/
o—xylene
1,3—Dichlorobenzene
l,4—Dichlorobenzene
1,2—Dichlorobenzene
1,2, 4—Trichloro—
benzene
Naphthalene
6
7
7
7
7
6
6
80
60
80
90
70
50
40
10
25
20
10
35
60
70
6
5
6
6
5
50
50
*
60
70
*
70
25
40
40
35
30
*Values too close to the detection limit to calculate reliably the
efficiency of removal.
38
-------
(except lime treatment) is illustrated in Figure 4. Illustration A represents
a chroinatogram of a CLS extract of a Q2 sample, illustration B one of a Q9
sample (samples taken 6/23/77). The column effluent was detected simulta-
neously with a flame—ionization detector and with an electron capture detector.
The major contaminants remaining at Q9 are those with a strong ECD response,
which represents halogenated substances produced by chlorination, mainly tn—
halogenated methanes as indicated previously under VOA analysis.
Solvent Extraction Analysis
Pesticides and PCBs——
During the initial period of WF21 operation, effiqent samples were ex-
tracted with hexane and tested for the organochlorine pesticides indicated in
the following. The detection limits for BHC, lindane, DDE, dieldrin, endrin,
aidrin, and heptachior were around 10 ng/i, and for DDT and methoxychior
around 100 ng/l. In the 15 samples analyzed between February 12 and June 24,
1976, no pesticides were found above these limits. In the second period from
October 1976 through June 1977, samples were analyzed and again, no pesti-
cides could be found in the effluent within the above detection limits (see
Appendix Table B—8).
Figure 5 shows the profiles of a typical chromatogram obtained from a
hexane extract of an influent sample (Qi). Figures 6A and 6B represent simi—
lar analyses of pesticide and PCB standards. None of the peaks matches unam-
biguously with those of the pesticides except for heptachlor. However,
investigations with GC/MS did not confirm this finding since no trace of
heptachior could be found. There is a pattern of peaks which matches a test
chromatogram of a PCB 1242 solution. Elemental sulfur was occasionally iden-
tified in the influent. Other peaks not belonging to the PCB pattern have
not yet been identified.
The measured PCB values are given in Table 24. Their concentrations in
the influent were consistently high. Values varied from 2.3 to 7.8 pg/i and
the average was 4.8 pg/i. Lime clarification reduced the mean concentration
to 1.3 pg/i and in all subsequent samples the mean values remained around 0.4
pg/i. This is the detection limit at this time and there may well be inter-
ferences which cause this relatively high number. In addition, the pattern
changes in some cases and no reliable quantification was possible. Estimated
values are given in parentheses.
Phthalates——
Diethylphthalate and dioctyiphthaiate (bis (2—ethylhexyi)--phthalate) were
quantified by means of the same internal standard. The dibutylphthalate peak
was obscured by a sulfur peak which prevented quantification. The mean val-
ues of the determined quantities of diethylphthaiate and dioctylphthaiate are
also given in Table 24. In the influent (Qi) and the lime—treated effluent
(Q2) the concentrations found are consistently in the low microgram per liter
level. Values range from approximately 1 to more than 10 pg/l. For diethyl—
phthalate no clear removal effects can be seen since individual measurements
seem erratic for unknown reasons. The mean value for dioctylphthalate was
lower after lime treatment (by about 60 percent). However during the
39
-------
B-
A.
Figure 4.
Chromatograins of CLS extracts with simultaneous flame ionization
and electron capture detection. A: Q2 taken 6/12—13/1977;
B: Q9 taken 6/12—13/1977 (numbers refer to Table 25).
40
! 10 20 30 40 50 TIME, mm
SOLVENT 58 88 118 148 178 TEMP, °C
B
29 23
28
I
0
29
B
22
0
L
SOLVENT
23
ATTEN
10 8
58
B.
20
88
30
118
40
148
50 TIME, mm
II
178 TEMP,°C
-------
0 0 20 30 TIME, mm
I L—.
90 210
70
1
230 TEMP, °C
Figure 5. ECD—chromatogram (setting 337/2k) of Qi extract, internal standard
2.34 pg/i. 1: dlethyiphthaiate; 4: dioctylphthalate; 3: retention
time as lindane; 2: unknown.
IS.
QI 5/1-2/77
POB
4
130
41
-------
I I.S.
2
j PESTICIDE STANDARD
8
I JJ
0 10 20 30 TIME., mm
F- II
90 130 170 210 230 TEMP, C
Figure 6A. Pesticide standard (ECD setting 337/2 ). 1: BHC isomers 260 pg;
2: lindane 260 pg; 3: heptachlor 160 pg; aidrin 160 pg; 7: diel—
drin 160 pg; 8: DDE 194 pg; 9: endrin 170 pg; 10: TDE 500 pg;
11: DDT 240 pg; 1.s.: internal standard, 1170 pg; 4,6: impurities.
PCB
IS. AROCHLOR 1242
0 10 20 30 TIME, mm
I II II I
90 30 170 210 230 TEMP, °C
Figure 6B. PCB arochior 1242 standard, 2.66 ng; internal standard, 0.464 ng.
Detector 337/2k.
42
-------
TABLE 24. PCBs AND PHTIIALATE CONCENTRATIONS AT VARIOUS SAMPLING POINTS*
April 1977 through June 1977
.
Sample Location
Influent
Qi
Clarif.
Effluent
Q2
Ammonia
Tower
Effluent
Q4
Filter
Effluent
Q6
Activ.—
Carbon
Effluent
Q8
Basin
Effluent
Q9
RO
Effluent
Q21B
PCB 1242
Mean, pg/i
Std. Dev., pg/i
Range, pg/i
No. ofSainp les
Diethyl phthalate
Mean, pg/i
Std. Dev., pg/i
Range, pg/i
No. ofSamp les
Dioctyl phthaiate
Mean, pg/i
Std. Dev., pg/i
Range, pg/i
No. ofSampies
4.8
2.0
2.3—7.8
6
6.1
4.4
2.5—13
5
8.2
5.0
1.7—14
5
1.3
1.0
0.3—3.1
6
8.3
3.7
1.7-19
5
2.8
2.9
0.3—7.6
6
(0.3)
0.5
0.1—0.8
6
5.6
3.7
2.1—10
6
1.0
0.6
0—2.0
6
(0.3)
0.4
0—0.8
5
10.9
8.2
3.6—21
5
1.3
0.7
0.4—2.0
5
(0.2)
0.4
0—0.8
6
5.8
4.9
0—13
6
1.4
1.4
0—4.0
6
(0.3)
0.4
0—1.0
8
2.5
2.6
0—6
8
2.0
2.0
0.4—6
8
0
3
1.3
0—2.7
3
2.0
0.4—5.3
3
*
Values in parentheses are estimates.
-------
subsequent treatment, the average concentration did not change significantly.
At this point the origin of these materials present in secondary effluent is
not known.
Detailed Characterization
A number of extracts have been investigated with GCIMS without an attempt
at quantification. The main emphasis to date has been to detect the presence
or absence of substances of toxicological concern. Since only a small number
of samples have been analyzed, no definite conclusions about variability in
contaminant levels can be drawn.
The organics found can be divided Into the following categories based
upon their presumed origin.
A. Aromatic hydrocarbons
B. Synthetic chlorinated compounds
C. Chlorination products
D. Natural products
E. Miscellaneous
The organic substances tentatively identified by GC/MS are listed in Table 25.
The numbers refer to Figure 7 which shows a total ion chromatogram of a CLS
extract of the Q2 sample taken on 2/6/77. The amount of internal standards
added (l—chloroalkanes; 1—Cl—C 2 , 1—Cl—C 8 , 1 —Cl—C 10 ) were 500 ng/l and compar-
ison of the peak heights may be used to approximate the concentrations. In
Table 25 relative heights in different sample locations are given which give
an indication of the degree of removal or formation during treatment. The
trend observed is the same as in the routine analysis: Ammonia stripping and
activated—carbon treatment are effective in removing the volatile organics.
Chlorination products are found in the influent and in the effluent. Their
concentration increases upon chlorination (see volatile organic analysis). In
addition to the haloforms, which are analyzed by the VOA, a number of other
substances which are produced by chlorination have been found: Halogenated
ketones (Peak 32, 24, 25) and chioroxylene (33). Their concentration is in
the low nanogram per liter range.
In Table 26 substances are listed which were found in the hexane ex
tracts. Identifications are based on mass spectra only and are tentative for
most substances.
44
-------
TABLE 25. COMPOUNDS IN WF—21 SAMPLES ANALYZED BY CLSA AND THEIR TOTAL ION
CURRENT PEAK HEIGHTS RELATIVE TO TIlE INTERNAL STANDARD, 1. C1_C8*
Peak No.
Sample Location
Clarif
Filter
Act iv.
Carbon
Basin
in
Effi.
Effi.
Effi.
Effi.
Figure 7
Co pound
Q2
Q6
Q8
Q9
A. Aromatic Hydrocarbons
1 Benzene
2 Toluene 3.32 0.76 0.26 0.24
3 Ethylbenzene 1.34 0.17 0.09 0.05
4 p—xy lene 0.80 0.15 0.08 0.05
5 in—xy lene 2.98 0.44 0.13 0.12
6 o—xy lene 1.27 0.44 0.13 0.12
7 C 3 _benzenest 0.5 0.15 0.06 0.05
8 C 4 —benzenes
9 Indane
10 C 1 —indanes
11 Naphtha lene 1.06 0.24 0.25 0.11
12 Nethy lnaphthalenes 0.67 0.18 0.06 0.1
13 C 2 —naphtha lenes
14 Styrene
B. Synthetic Chlorinated Compounds
15 Trichioroethylene 1.12
16 Tetrachioroethylene
17 Trichioroethane Tr
18 Hexachioroethane 0.4 0.24 0.08 0.08
19 Chlorobenzene
20 1, 2—dichlo rob enzene
21 1,3- .dich lorobenzene 1.11 0.09 0.01
22 1,4—dichlorobenzene 2.94 0.29 0.05
23 Trichlorobenzene 0.87 0.06 0.01
24 Tetrachlorobenzene
25 PCB (1— and 2—chiorines) Tr
C. Chlorination Products
26 • Chloroform
27 Dichlorobromomethane 0.3 0.53 0.23 0.20
28 Chlorodibromoniethane 6.3 0.27 0.32
29 Bromoform 0.45
30 Dichloroiodomethane 0.09 0.09 0.03
31 Chiorobromo iodomethane
32 1,l,l—trichloroacetone
33 Chloroxylene
34 Chlorobromopentanone
35 Bromoketone 0.3 1.1 0.12 0.12
TABLE 25 continued
45
-------
TABLE 25 continued
Peak No.
in
Figure 7
Compound
Sample Location
Clarif.
Effi.
Q 2
Filter
Effi.
Q6
Activ.
Carbon
Effi.
Q8
Basin
Effi.
Q9
36
37
38
39
40
41
42
D. Natural Products
0.05
> 4
1.97
1
0.34
0.20
1.0
Terpene
Terpene alcohol
E. Miscellaneous
Phthalates
Benzaldehyde
Tolualdehydes
Ethyiphenol
Apparent MW 196
*
blank indicates peak height not measurable.
tValue of one typical compound of this group measured.
TABLE 26. STJBSTABCES TENTATIVELY IDENTIFIED IN HEXANE EXTRACTS
Substance
Sample Location*
Clarif.
Effl.
Q2
Basin
Effl.
Q9
PCB (see Table 24)
Biphenyl
Alkylated biphenyls
Phenanthrene/Anthracene
Methylphenanthrene
Diethylphthalate (Table 24)
Dibutylphthalate
Dioctylphthalate (Table 24)
Sulfur S 8
x
X
X
x
X
x
X
x
X
Tr
Tr
Tr
x
X
X
*
x = present in measurable concentration.
Tr= close to detection limit.
—— = not detectable
The complexity of the mass spectra did not allow an identifica-
tion of a number of peaks yet.
46
-------
0-2 2/6/77 2S IS
Q-2 2/6/77 250 IS
100
150
00
c j
Figure 7. Typical total ion chromatogram (computer reconstructed) of a CLS
extract from Q2. Lower graph is independently normalized.
Numbers refer to substances in Table 25.
L
( -ii
1!
N -.
‘1
L
‘I
‘-I
-l
CN
TIC 2
c — i
50
200
00
250
47
-------
VIRUS
James N. Montgomery Engineers (JMM) determined the number of virus in
samples taken from the following locations at Water Factory 21: (1) the in—
fluent, Qi, (2) the lime—clarifier effluent, Q2, and (3) the final effluent,
Q9. In addition, samples were analyzed occasionally to determine the types of
virus present. Most identifications were conducted by the California Depart-
ment of Public Health, but some were made by JMM.
Virus in Water Factory 21 Influent
A snmm ry of results for native virus assays of influent samples is given
in Table 27 and Figure 8. The geometric mean values listed at the bottom of
Table 27 were taken from the 50—percent value from Figure 8 for the period
from November 1975 through June 1976, and from a similar plot for the data
from October 1976 through July 1977. Several samples analyzed had no detect-
able viruses. For example, of the 77 samples analyzed between October 1976
and July 1977, 29 contained no detectable viruses (Table 27). The number of
viruses which were measured in the remaining samples are listed in increasing
order in the tables.
A comparison of the data in Table 27 for the two different periods indi-
cates that for the BGN procedure, plaque confirmation as defined in the Sampl-
ing and Analytical Procedures section is essential. The values obtained for
the second period when confirmation of the assay results was made were thirty-
fold lower than for the first period when it was not.
Figure 9 illustrates the seasonal distribution of virus, and as commonly
believed, the data suggest that virus levels are lowest during the winter and
highest during the summer. Also, between December 1, 1976 and March 15, 1977
only 48 percent of the samples were positive for virus, while during the
warmer remainder of the year, 68 percent of the samples were positive.
Table 28 presents a summary of the viruses identified in influent samples
to Water Factory 21. The significance of these particular virus isolates in
relation to human disease has not been investigated.
Virus in Chemical Clarifier Effluent
Virus were measured in the effluent from the clarifier after lime treat-
ment (Q2) only during the first period from November 1975 through June 1976.
The purpose was to determine the effectiveness of lime treatment at pH greater
than 11.3 on virus reduction. During this period, however, the viral assays
were not confirmed as this was then not known to be necessary, and so actual
effluent concentrations are not known. The results do suggest, however, that
reductions by lime treatment are significant. A summary of the analyses con-
ducted Is given in Table 29. The geometric mean values were obtained as be-
fore from the intersection of the drawn line through data on log—probability
paper with the 50—percent point on the graph. A comparison of the calculated
geometric mean values with those for the same period and same assay procedure
in Table 27 indicates that lime treatment resulted in 99.88 percent reduction
48
-------
TABLE 27. VIRUS CONCENTRATION IN INFLUENT (Q1)
November 1975 through June 1976
Oct. 1976 through July 1977
PAG (unconfirmed)
BGM (unconfirmed)
BGN (confirmed)
No. of
Samples
iø pfu/m 3
No. of
Samples
,
1O 3 pfu/m
No. of
Samples
10 pfu/m 3
1 N.D.* 0 29 N.D.*
1 0.18 1 4.0 5 0.5
1 2.0 1 6.6 5 0.8
1 2.5 1 10.6 2 1.1
1 3.2 1 12.5 7 1.3
2 4.0 1 13.2 1 1.6
1 5.0 1 16 3 1.9
1 5.3 1 26 3 2.1
1 8.7 1 29 1 2.4
1 9.3 1 40 1 2.6
1 13.2 1 49 1 2.9
1 148 1 52 1 3.2
1 63 2 3.4
1 160 1 3.7
1 260 2 4.2
1 4.5
1 4.8
2 5.0
2 5.3
1 5.6
1 5.8
1 6.1
1 6.6
1 6.9
1 7.1
1 48
13 4.5 14 27 77 1.1
(Total (Geom. (Total (Geom. (Total (Geom.
Samples) Mean) Samples) Mean) Samples) Mean)
*
None detected.
as determined by the unconfirmed PAG procedure and 97.7 percent by the uncon—
firmed BGM procedure.
Samples obtained during this period were also analyzed by the California
Department of Public Health. For influent samples the State laboratory found
all 12 samples analyzed to be positive. For samples after chemical treatment,
49
-------
%J I
.05
.5
5
I0
20
40
60
80
90
95
99
99.9
99.99
.01
.1 I 10 100
VIRUS ASSAY, thousand PFU/m 3
Figure 8. Probability plot of virus assay levels.
LU
-j
z
LU
>
V I
U,
U)
(I)
0
F-
z
LU
U
LU
50
-------
TABLE 28. VIRUSES IDENTIFIED IN WATER FACTORY 21 INFLUENT (Q1)
Virus
Calif. Dept. of Health
James Montgomery
No. of
Samples
Total No.
of Plagues
No. of
Sample
Total No.
of Plagues
Polio2 16 27 1 4
Echol 8 17
Echo7 7 16
Reo2 5 12
Echol4 7 8
Coxsackie B5 6 8 1 1
Polio3 7 7
Echo8 6 6
Reo 6 6
Unknown 5 5
Echol2 3 5
Coxsackie B4 5 5
Coxsackie B2 3 4
Coxsackie B3 1 3
Echoll 2 3
Reol 3 3
Coxsackie B6 2 2
Coxsackie A17 2 2
Coxsackie A13 1 1
Coxsackie A18 1 1
Coxsackie A20 1 1
Echo3 1 1
Echo9 1 1
Echol9 1 1
Echo25 1 1
Poijol 1 1 1 1
Total No. Samples with Virus 46 4
the State laboratory found only 3 samples to be positive while JMM found 28
ositives. This discrepancy again indicates the importance of conducting
confirmed analyses. It also leaves open the question of the true effective-
ness of lime treatment on virus reduction. The three viruses identified in
the three positive samples by the State laboratory for lime—treated effluent
samples were Echo 8, Echo 20, and Polio 1. Of the three, only Echo 8 was
also found in the plant influent during this period.
Viruses in Final Effluent (Q9 )
Over the period of this study, 77 samples of chlorinated final effluent
(Q9) were analyzed for virus. Only one of the samples analyzed was positive
for virus. This sample was collected on March 1, 1977. There was one con—
firmed plaque in the four ml assayed in this sample. Identification by the
51
-------
48
I0
8
In
E
z
4
cfl4
0
I
I.-
2
0
OCT
NOV
1976
E 1
ii
E L]
DEC
JAN
FEB
MAR
APR
1977
MAY
JUN
JUL
Figure 9. Seasonal variation in natural viruses in Water Factory 21 influent.
-------
TABLE 29. VIRUS CONCENTRATION IN CHEMICAL CLARIFIER EFFLUENT (Q2)
November 1975 through June 1976
FAG (unconfirmed)
BGM (unconfirmed)
No. of
Samples
pfu/rn 3
No. of
Samples
1O 3 fufm 3
15
N.D.
4
N.D.
3
0.03
1
0.05
1
0.05
2
0.11
2
0.08
1
0.13
1
0.53
1
1
2
5
1
2
1
1
1
1
2
1
1
2
1
1
0.19
0.20
0.3
0.5
0.8
1.1
1.3
1.6
1.8
2.1
2.6
3
4
5
7
11
22
0.005
32
0.6
(Total
(Geoni.
(Total
(Geom.
Samples)
Mean)
Samples)
Mean)
plaque reduction technique indicated that it was Polio Type 2. The one con-
firmed plaque in four ml assayed for the plant influent (Qi) on that same day
was also identified as Polio Type 2.
The firm of .1MM which conducted the assays for virus indicated the pos-
sibility that the virus could have resulted either from cross—contamination
or was actually indigenous to the effluent sample analyzed. They felt that
the possibility of cross—contamination was low and thus the virus was most
likely indigenous to the sample.
On the day that the virus was detected, there was an operational problem.
An unusually high concentration of activated—carbon fines was in the effluent;
for this reason the turbidity was 2.3 and the pH was 6.6. At the time of
sampling, the chlorine residual was not determined, but because of normal
interactions between chlorine and activated carbon, it could have been low.
53
-------
It has been well documented that the presence of particulates interferes
with disinfection. Activated carbon has been shown to be a very effective
virus adsorbent, consequently any virus in the effluent would likely be on
the carbon. Activated carbon also reacts very quickly to remove chlorine and
as a result the attached virus are likely to have been protected from its
action. The release of activated—carbon fines has been an occasional problem
at Water Factory 21 and for this reason, some major modifications have been
completed in an effort to reduce the problem.
54
-------
SECTION 7
DISCUSSION
BACKGROUND
This study has been conducted to evaluate the effectiveness of advanced
wastewater treatment for removal of inorganic, organic, and biological con—
taminants which remain in municipal wastewater after normal secondary treat-
ment. The performance of Water Factory 21 was evaluated during the first one
and one—half years of its operation. This advanced treatment plant receives
up to 0.66 m 3 /sec (15 mgd) of trickling filter effluent from the Orange County
Sanitation District and treats it by a combination of physical and chemical
processes. The ability of this treatment plant to effectively remove many
materials of toxicological significance prior to reuse or gro undwater injec-
tion has been demonstrated. The information this study has generated should
be useful in evaluations of the reliability of advanced treatment plant opera-
tion and the determination of quality of reclaimed waters relative to that of
potential alternative supplies.
GENERAL INORGANICS
The advanced was tewater treatment at Water Factory 21 has resulted in
changes in the concentrations of ammonia, phosphate, calcium and magnesium.
In addition, treatment of a portion of the wastewater by a reverse osmosis
pilot plant has resulted in a significant reduction of inorganics in general.
Ammonia is removed both by air stripping and by breakpoint chlorination.
During the first six months of operation only ammonia stripping was practiced,
and this process reduced the concentration of ammonia nitrogen from 43 to 19
mg/i for an average removal of 56 percent. The operation of the two strip-
ping towers was then modified to provide for series rather than parallel op-
eration. Even though the same quantity of air was used (3000 IL 3 air/rn 3 water),
this change resulted in decreasing the ammonia nitrogen from 37 to 6.5 mg/i,
which is a reduction of 82 percent. Thus, series operation offers a decided
advantage.
Breakpoint chlorination resulted in reduction of ammonia nitrogen to the
1 mg/i level required by regulations. This necessitated a chlorine to ammo-
nia nitrogen weight ratio of 9 or greater. Breakpoint chlorination was dif-
ficult to control when it was combined with disinfection in the final chlorine
contact chamber because the high concentration of chlorine required resulted
in an excessive decrease in pH. This problem was solved by moving the
55
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breakpoint chlorination process upstream to the effluent from the ammonia
stripping tower. Here, the pH was near 11 and the water had a good buffering
capacity. After chlorine addition, the pH was lowered to the desired level
by recarbonation, and the recarbonation basins provided the time required for
ammonia oxidation to be completed.
A significant disadvantage of breakpoint chlorination, however, was the
forniationof several chlorinated organics which were not efficiently removed
by activated—carbon adsorption. This was previously discussed more fully
under the section on Organics. There was also concern over the effect the
resulting free chlorine residual might have on the capacity of the activated—
carbon columns. For these reasons and because the cost of breakpoint chlori-
nation is high, the OCWD has requested that the 1 mg/l limit on ammonia nitro-
gen In injection water be reviewed, especially since some additional removal
by ion exchange In the aquifer Is likely.
Chemical treatment with lime at a pH greater than 11.3 is very effective
for the removal of phosphates and magnesium. Over the entire one and one—half
years of this study, phosphate phosphorus was reduced from a mean influent
concentration of 5.5 mg/i to 0.08 mg/i, or 99 percent, and magnesium was re-
duced from a mean influent concentration of 25 mg/l to 0.7 mg/i, or 97 percent.
Calcium concentration, however, increased through lime addition during the
first six months of operation from 102 mg/i to 142 mg/i, but was reduced dur-
ing ammonia stripping, recarbonation and settling to a final effluent concen-
tration which averaged 107 mg/i.
During the last year of operation, a pilot reverse osmosis (RO) system
was operated to determine efficiency for dissolved salt removal which could
be expected when the 0.22 m 3 /s (5 mgd) full—scale facility was completed.
The pilot RO unit reduced the specific conductance from a mean value of
1530 to 80 S/cm,or by 95 percent. It also reduced the sodium, chloride, sul-
fate, and COD concentrations by 93, 94, 100, and 93 percent, respectively.
Certain low molecular weight organics were not removed effectively as dis-
cussed later under the section on Organics. However, the above results indi-
cate that RO treatment is quite effective for removal of a broad range of
general inorganics and organics.
HEAVY METALS
Of the several heavy metal trace contaminants monitored, only one was
continuously higher in concentration In the secondary influent to Water Fac-
tory 21 than the regulatory requirements for the effluent from the advanced
wastewater treatment plant. This was chromium, and it was removed down to
the regulatory requirement of 50 ug/l by the treatment processes. Thus, heavy
metal removal is not a critical aspect of Water Factory 21 operation. How-
ever, it is worthwhile to consider the effectiveness of heavy metal removal
by the treatment plant both for other applications and because several trace
metals in the influent on occasion rise above the limits.
Two metals, mercury and selenium, were not removed to a significant de-
gree by the advanced wastewater treatment system. Also, arsenic was not
56
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removed significantly during the last year of operation, although during the
first six months there was an indication that chemical treatment removed some-
what over 50 percent. All three metals were in the low g/l range, near the
detection limit. Therefore, firm conclusions about removability cannot be
made.
All other trace heavy metals monitored were generally removed 50 percent
or more by chemical treatment. These included barium, cadmium, chromium,
iron, lead, manganese, silver, and zinc. Subsequent treatment (RO was not
evaluated, however) did not result in additional removal except for chromium,
copper, and zinc which were reduced an additional 41, 64, and 78 percent, re-
spectively, by activated—carbon treatment.
Chemical treatment was consistently good for iron and manganese, provid-
ing over 85 percent removal. Copper removals averaged between 65 and 75 per-
cent for the two different periods, and barium removal varied between 50 and
60 percent. Silver, chromium, lead, and cadmium removals averaged from 40 to
65 percent during the first six months, but increased during the last year of
operation to over 75 percent, with cadmium reductions the best at 94 percent.
On the other hand, zinc removal was highest during the first period (90 per-
cent) and lowest during the second period (37 percent).
Iron and zinc concentrations were quite variable throughout the plant,
especially during the first six months of operation, due to corrosion, espe-
cially in the ammonia stripping tower. Zinc in particular increased in con-
centration from 29 to 670 jig/l through ammonia stripping, although the concen-
tration was then reduced to 133 pg/l by activated-carbon treatment. The
corrosion problem was not so severe during the last year of the study.
These results indicate that the concentration of many heavy metals of
health concern can be reduced by chemical treatment with lime at a pH greater
than 11.3. This treatment should provide a good safeguard against occasional
high concentrations of heavy metals, which may be present in municipal waste—
waters. In the case at hand, however, in the influent water only chromium
exceeded the regulatory requirements for the effluent and necessitated reduc-
tion on a continuous basis. Some of the other metals exceeded requirements
occasionally, thus treatment was required to insure continuous compliance
with regulations. Lime treatment was the most effective process in general
at Water Factory 21 for this purpose.
ORGANICS
General
The COD analysis measures a broad group of organic compounds and thus
changes in ttu.s parameter provide indications of the overall performauce or
the treatment system for organics in general. The COD of the secondary in—
fluent to Water Factory 21 averaged 131 mg/i. This was reduced by 60 percent
(about 36 percent particulate and 24 percent dissolved) to a mean concentra-
tion of 52 mg/l by chemical treatment due to the removal of suspended organics.
57
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An additional reduction in the mean COD concentration to 45 mg/i took
place after ammonia stripping and filtration. Activated—carbon adsorption
provided an additional 67 percent reduction to a mean value of 15 mg/i, which
had a standard deviation of 8 mg/i in the 397 samples analyzed over the one
and one—half years of operation. Thus, overall COD reduction by the advanced
wastewater treatment plant was almost 90 percent. While the COD procedure
provides information on organics in general, it does not indicate the perfor-
mance for removal of many individual organics which may be of toxicological
concern.
Trace Organic Contaminants
The trace organics identifiable by closed—loop stripping analysis have
been divided arbitrarily Into five separate groups as related to their most
probable origin. Presence of Group A compounds reflects contamination of
water with petroleum products. This can be concluded from the fact that var-
ious groups of isomers such as the xylenes are present in typical relative
concentrations. Quantification of the complex mixture of substances in petro-
leum products is obviously very difficult. The aliphatic portion of such
products are probably removed to a large degree during secondary treatment,
either due to their better microbial degradability or through aeration. This
was indicated in an earlier investigation (6).
The Group B synthetic chlorinated products are widely used in household
and in industry. They are commonly found in natural waters and in drinking
water supplies of all industrialized nations (8). Their occurrence in Water
Factory 21 samples is therefore not surprising. The first quantitative esti—
mates indicate that they are present all the time.
The Group C compounds are formed during the chlorination process in water
and wastewater treatment plants, and include the well—known haloforms (2,3,10).
However, other chlorinated organics such as chloroxylene (7), and alpha—
haloketones (6) are also known to be formed, leading us to assume that these
compounds as well as the bromochloroketone and trichloroacetone found are
products of chlorination at Water Factory 21 and of its chlorinated influent.
The Group A alkylated benzenes may also be chlorinated (7). The structure of
some of the organics which resulted from chlorination remain to be elucidated.
Natural products identified include terpenes and terpene alcohols.
Little attention has been given to these materials since they are not of
health concern. They are removed effectively during treatment.
The Group E substances do not fit into the other categories. Except for
phthalates, which are widely used as plasticizers, little is known of their
origin.
The SEA analysis permits the identification of additional groups of com—
pounds, including chlorinated pesticides, PCBs, and some of the polynuclear
aromatics. They are of public health concern and some members are included
in the EPA primary drinking water standards and those formulated by the World
Health Organization (13). Additional information on their frequency distribu-
tion in reclaimed waters is desirable.
58
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A major concern is the high concentration of polychlorlnated biphenyls
in the plant influent. It was found to be about 10 times higher than in an
earlier investigation (16). Although they are removed to a large extent,
traces have been found in the effluent. A more sensitive procedure will al-
low more precise monitoring of PCBs in the product water. On the other hand,
chlorinated hydrocarbon pesticides were not detected. Schmidt, Risebrough,
and Gress (16) reported a DDT concentration up to 0.64 pg/i. The current
lack of detection probably reflects the fact that this pesticide is no longer
in heavy use.
Efficiency of Advanced Wastewater Treatment
The initial results from this study indicate that advanced was tewater
treatment is capable of removing about 90 percent of the total organic mate-
rial remaining after primary and secondary treatment of municipal wastewaters.
For many of the relatively low molecular weight organics of health concern,
the efficiency of removal was greater than 90 to 95 percent. On the other
hand, there was a group of organics which were formed by chlorination, and
the effluent concentration of these was greater than the influent concentra-
tion. A problem for future operation is how to minimize the formation of
such chlorination products and at the same time satisfy other effluent re-
quirements related to pathogens and nitrogen species.
Chemical clarification and activated—carbon adsorption are well—known
processes for removing organic materials. This study has demonstrated that
air stripping for ammonia removal is also highly effective for the removal of
a wide range of organic materials of toxicological significance. In particu-
lar this process is effective in removing a wide range of highly volatile,
low molecular weight, and relatively nonpolar organics which are not easily
removed by activated—carbon adsorption or reverse osmosis. Included are
several one— and two—carbon halogenated solvents and chlorination products.
In addition, several aromatic compounds such as chlorinated and alkylated
benzenes and naphthalenes are significantly removed by air stripping, thus
reducing the need for reliance solely on activated—carbon adsorption. An ad-
ditional important aspect for Water Factory 21 is that the group of organics
removed by air stripping are some of the most likely compounds to cause prob-
lems If Injected into a groundwater aquifer, because of their refractory
nature and potential for movement with little hinderance from adsorption.
The intermedla transfer of organics from the water to the air by ammonia
stripping may cause some concern, and the environmental implications need to
be considered. This should be viewed in a broad context since a similar in—
termedia transfer would no doubt result from any discharge of wastewaters to
surface waters, whether or not ammonia stripping is employed. An additional
consideration is that the lifetime of many refractory organics is less in
the air because of exposure to solar radiation than In the ground. A reso—
lution of these complex issues was not attempted in this study.
The formation of chlorinated organics by breakpoint chlorination raises
additional issues which need to be resolved. Are health risks in a ground-
water injection system greater from pathogens or from chlorinated organics?
Is removal of ammonia to low levels, requiring breakpoint chlorination,
59
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necessary to the satisfactory operation of an injection system and to the
quality of withdrawn water? These questions also have not been addressed in
this study but remain for future research.
This study has shown that the combination of processes used at Water Fac-
tory 21 is effective for reducing the concentration of a broad range of organic
materials present in effluents from secondary wastewater treatment. Future
studies will be concerned with additional quantification of materials of
health concern, seeking of analytical procedures for other organics of impor-
tance, and determining their variation with time in Water Factory 21 effluent.
The information provided should aid in the formulation of policy decisions
about wastewater reuse in general, and in particular for municipal purposes.
VIRUS
Enteric viruses have been found present in a majority of the Influent
samples to Water Factory 21. Over 25 different viruses have been identified
in these samples. A reduction in viral numbers appears to occur during chem-
ical treatment, although this analysis was conducted during the first six
months of operation, when confirmed assays were not conducted. Subsequent
studies have Indicated that confirmed analyses are essential to a good inter-
pretation of data.
Over 77 samples of final effluent were analyzed for virus concentration.
Only one sample was positive for virus. This positive response appears to be
related to the discharge of a relatively high concentration of activated—
carbon fines In the effluent. Water Factory 21 has recently undergone modif I—
cation to reduce such carbon fines in the future, which should also reduce
the potential for virus passage.
PLANT RELIABILITY
An important aspect of this study was an evaluation of the reliability
of Water Factory 21 to produce an effluent with good consistency in quality.
In order for a plant to be reliable, either (1) the plant must be able to
successfully treat wastewaters with great variability In quality, (2) the
flexibility must be available so that the treatment plant need not accept a
wastewater for treatment if It Is of questionable quality, or (3) if the
treated water does not meet the intended reuse criteria, then it must be pos-
sible to dispose of it by other means. In addition, the treatment plant must
be able to treat the wastewater with its normal variability and consistently
and reliably improve its quality to the required level.
Water Factory 21 has been designed to provide considerable flexibility
in line with the above. The OCWD can treat wastewater at whatever constant
flow rate It desires. The Orange County Sanitation Districts, which supply
the secondary effluent to OCWD, have on occasion had problems either in the
operation of their biological treatment plant or with the introduction of un-
usual wastes into the contributing sewers. They have then notified the OCWD,
and if found desirable for water quality considerations, Water Factory 21 has
60
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been shut down. Water Factory 21 is also routinely shut down for a period of
two to three months each year for general maintenance or plant modifications.
In addition, plant operation is stopped whenever desirable for emergency
maintenance or less extensive modifications. When the plant is restarted,
treated water can be discharged to a sewer until the quality is consistent
with regulatory requirements. This flexibility is possible since the ef flu-
ent is recharged to the groundwater aquifer which is a large storage basin,
unaffected by short—term stoppages in the injection of treated water.
The plant operation can be properly balanced within one day after
starting and effluent quality is then consistent and adequate. The ability
to stop plant operation at will and to restart it rapidly gives a good meas-
ure of assurance on plant reliability.
The other measure of reliability is consistency in the characteristics
of the reclaimed water. A measure of this can be obtained from the variabil-
ity in measured effluent quality. Table 30 indicates the variability of in-
organic constituents and Table 31 the variability of organic constituents in
Water Factory 21 effluent. Most values represent analyses of final effluent
after chlorine contact (Q9), although some as indicated are from before chlo-
rine contact (Q8). The values are summarized from the detailed results listed
in Appendix B.
TABLE 30. VARIABILITY OF INORGANIC CONSTITUENTS IN WATER FACTORY 21 EFFLUENT
Constituent
January through
June 1976
October 1976 through
June 1977
Mean Conc.
Coef.
of Var.,
%
Mean Conc.
Coef.
of Var.,
%
Ca, mg/i
107
22
Na, mg/i
205
9
Cl, mg/i
246
9
SO 4 , mg/i
312
13
Alkalinity, mg/i
137
19
B, mg/i
0.63
22
F, mg/i
0.64
25
EC, pS/cm
1470
9
pH
6.7
2
Turbidity, TU
0.85
45
NH 3 —N, mg/i
3.3
88
As, pg/i
1.1
27
2.4
75
Ba, pg/i
33
70
31
71
Cd, pg/i
2.2
82
1.7
100
Cr, pg/i
48
67
26
92
Cu, pg/i
27
52
32
47
Fe, pg/i
45
150
66
120
Pb, pg/i
26
123
5.2
240
Mn, pg/i
4.1
34
4.9
90
Hg, pg/i
4.9
430
6.7
210
Se, pg/i
6.4
55
<2.5
—
Ag, pg/i
14
410
1.5
190
Zn, pg/l
124
58
162
48
61
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TABLE 31. VARIABILITY OF ORGANIC CONSTITUENTS IN WATER FACTORY 21 EFFLUENT
Constituent
January through June 1976
October 1976 through June 1977
Mean Cone.
Coef. of Var., Z
Mean Conc.
Coef. of Var., 7
COD, mg/i 13 62 18 39
TOC, mg/i 7.3 36 6.7 33
Org—N, mg/i 0.6 67 1.3 38
CHC1 3 , pg/i 2.1 52 10 84
CHBrC1 2 , pg/i 0.9 iii 3.6 83
CHBr 2 C1, pg/i 2.0 115
CHBr 3 , pg/i 0.4 150
CH 2 C1 2 , pg/i 3.4 160
C1 3 C—CH 3 /CC1 4 ,
pg/i 0.1 300
C1 2 C=CHC1,pg/1 0.04 250
CC 1 2 =CC 1 2 ,pg/1 0.1 300
Ethyl benzene,
ugh 40 125
Ch lorobenzene/
o—xylene,ng/1 70 130
1, 3—dichioro—
benzene, ng/i 140 130
1 ,4—dichioro—
benzene, ng/1 20 50
1, 2—dichioro—
benzene, ng/1 100 80
1,2, 4—trichioro—
benzene, ng/1 120 160
Naphtha lene,ng/1 30 67
PCB 1242, ng/i 300 130
Diethyl-
phthalate,ng/i 2500 104
Dioctyi—
phthaiate,ng/1 2000 100
The coefficients of variation listed in Tables 30 and 31 were obtained
by dividing the standard deviation for each constituent analysis by the mean
value and multiplying by 100. The result indicates the magnitude of the stan-
dard deviation in relationship to the mean. The mean and standard deviation
indicate the magnitude and spread of the data. If the data followed a normal
distribution, one could calculate from these values the frequency at which a
given effluent concentration for a given constituent would be exceeded in the
treated effluent.
Table 30 indicates that the variability of the general inorganic con-
stituents which comprise the major portion of the total dissolved solids is
low, the coefficient of variation Is generally less than 25 -percent. The
62
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variability of turbidity, ammonia concentration, and heavy metals in general
is much greater, sometimes exceeding 100 percent. Constituents falling in the
latter category are cadmium, iron, lead, mercury, and silver. A portion of
this variability is due to the fact that these concentrations are near the
analytical limit, at which point analytical errors tend to be quite high. At
such concentrations, contamination of samples can be a serious problem and
may contribute to the variability found. The high coefficients of variation
indicate that the mean values are affected significantly by a few high val-
ues. Also, coefficients of variation greater than 100 percent, and indeed
somewhat lower than this, suggest that the data do not follow a normal dis-
tribution. Probably a log normal distribution would fit the data much better.
This will be studied in more detail during the coming year of research.
The variability of organic constituents is shown in Table 31. That of
the gross parameters such as COD, TOC, and organic nitrogen are not as great
as for the individual constituents. Again this is partly reflective of the
variability of the analysis itself. The coefficient of variation is particu-
larly high for constituents such as C1 3 C—CH 3 /CC14, C1 2 CCHC1, and CC1 2 CC1 2
which are present in concentrations just at the borderline of detection. The
great variability here can be attributed largely to analytical problems. For
other constituents, with coefficients of variation near 100 percent, analyti-
cal problems are partly responsible, but most of the variation probably can
be attributed to actual variation in effluent quality.
It is no doubt desirable to be able to separate that portion of the meas-
ured constituent variability which is due to analytical errors and that which
is due to actual variation in treatment plant quality. However, for each
constituent of concern this can be a costly undertaking. The decision to make
the effort required should properly be related to the actual need for more re-
fined numbers. If the constituent is at a measured concentration which is
near a required limit, or if it exceeds the limit on occasion, then for that
constituent, more refined measurements may be fully justified. If even at
the highest concentrations measured, a given constituent is far below the re-
quired limit, then additional refinement can probably not be justified. Since
there are presently no regulatory requirements for organics except COD, addi-
tional refinements for most of the organics listed are perhaps not justified
at this time.
Another aspect of reliability in performance which must be considered at
*ater Factory 21 is ability of the aquifer itself to even out the variations
which occur. The aquifer system represents a very large reservoir. As the
reclaimed wastewater is injected into it, the organics will adsorb to and
then be desorbed from the clays, and by this process they will move more
slowly through the system than the water itself. This process of adsorption
and desorption will result in spreading of the peak and valley concentrations
of given organics so that variations of a given constituent at an observation
well will be very much less than in the injected water. This effect will be
greater the further the distance of the observation well from the point of
injection. For this reason, the mean concentration may be a much more mean-
ingful value than the extremes in reclaimed effluents used for groundwater in-
jection. It must be kept in mind, however, that if variation in effluent
quality is great, then many more samples must be analyzed in order to calcu-
late a mean value which is sufficiently close to the true mean.
63
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REFERENCES
1. Standard Methods for the Examination of Water and Wastewater (14th ed.).
American Public Health Association, Washington, D.C., 1976.
2. Bellar, T. A., and J. J. Lichtenberg. Determination Volatile Organics
at the pg/i Level in Water by Gas Chromatography. Jour. AWWA, 67:634,
1974.
3. Symons, J. N., et al. National Organics Reconnaissance Survey for
Halogenated Organics in Drinking Water. Jour. AWWA, 67:634, 1975.
4. Argo, David G. Wastewater Reclamation Plant Helps Manufacture Fresh
Water. Water & Sewage Works, Reference Issue, R—160, April 30, 1976.
5. U.S. Environmental Protection Agency. Methods for Organic Pesticides in
Water and Wastewater. National Environmental Research Center, Cincinnati,
1971.
6. Giger, V., N. Reinhard, C. Schaffner, and F. Zurcher. Analysis of Organic
Constituents, Chapter 26 in Identification and Analysis of Organic Pollu-
tants in Water (L. H. Keith, ed.), Ann Arbor Science Publishers, Ann
Arbor, Michigan, 1976. pp. 433—452.
7. Reinhard, M., V. Drevenkar, and W. Giger. Chlorination cf the Aromatic
Fraction of Dieselfuel. Jour. Chromatogr., 116:43, 1976.
8. Keith, L. H. (ed.). Identification and Analysis of Organic Pollutants
in Water, Ann Arbor Science Publishers, Ann Arbor, Michigan, 1976.
9. Argo, D. G. Advanced Wastewater Treatment Produces a Recyclable Product.
Proc. 5th Ann. md. Pollu. Control Conf., Water and Wastewater Manufac-
turer Assoc., April 1977, pp. 223—254.
10. Rook, J. J. Formation of Haloforms during Chlorination of Natural Waters.
Water Treatment and Examination, 23(2):234—254, 1974.
11. Stenhagen, E., S. Abrahamsson, and F. W. MacLafferty (eds.). Registry
of Mass Spectral Data, John Wiley & Sons, New York, 1974.
12. Grab, K., and F. Zurcher. Stripping of Trace Organic Substances, Jour.
Chromatogr., 117:285, 1976.
13. World Health Organization. European Standards for Drinking Water, 2nd
ed., 1970.
64
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14. Grob, K., and G. Grob. Techniques of Capillary Gas Chromatography, Jour.
Chromatogr., 5:3, 1972.
15. Law, M. L. R., and D. F. Goerlitz. Microcoluinn Chromatographic Cleanup
for the Analysis of Pesticides in Water, Jour. of the AOAC, 53(6):1296,
1970.
16. Schmidt, T. T., R. W. Risebrough, and F. Gress. Input of Polychiorinated
Biphenyls into California Coastal Waters from Urban Sewage Outfalls,
Bull. Env. Cont. & Tox., 6(3):253, 1971.
65
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APPENDIX A
TABLE A—i. MAJOR DESIGN CRITERIA
OCWD 0.66 m 3 /s ADVANCED WASTEWATER TREATNENT PLANT
INFLUENT PUMP STATION
Number of pumps: 32
Capacity: 0.41 in Is @ 8.8 m TDH 0.44 m 3 /s @ 8.2 in TDH
Type: Vertical mixed flow
CHEMICAL CLARIFICATION SYSTEM
Rapid Mixing
Number of basins: 2 in series
Mechanical mixer in each basin
Dimension: length — 3.7 in; width — 3.7 in; depth — 3.7 in
Detention time: 2.4 minutes total @ 0.66 m 3 /s
Chemical addition: First basin — lime, alum, recycled lime sludge
Second basin — polymer
Flocculation
Number of basins: 2, three compartments each 3
Detention time: 10 nun/compartment (30 mm total) @ 0.66 in Is
Chemical addition: Polymer, 1st and 3rd compartments
Dimensions: length — 15 in; width — 12.5 in; depth — 3.4 in
Flocculator mechanism: Oscillating type
Settling Basins
Number of basins: 2 rectangular
Dimensions: 37 in long x 12 in wide, each
Surface Overflow Rate: 2.7 m 3 /m 2 —hr @ 0.66 m 3 /s
Each basin equipped with settling tubes
Clarifier Effluent Pump Station
Number of pumps: 4
Capacity: 0.21 m 3 /s @ 23 in; 0.22 m 3 /s @ 20 in
Discharge: To ammonia stripping tower or to the OCSD plant or to
the recarbonation basins
Lime Feeders and Slakers
Number: 2 gravimetric feeders and paste type slakers
Capacity: 0.5 kg/s
66
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TABLE A—i. (continued)
Polymer Feed System
Number of mixing tanks:
Number of feed pumps: 3 4
Capacity: 0 to 0.1 in /h
2 (4 in 3 each)
dual head
each head
Alum Feed System
Number of storage tanks:
Number of feed pumps: 3
Capacity: 0.1 in 3 /h each
2 (18 m 3 each)
(2 double head and 1 single head)
head
AMMONIA STRIPPING/COOLING TOWERS
Number of towers: 2
Dimensions: length — 63 in; width
Capacity: 0.33 m 3 /s each @ 0.044
Number of fans: 6 per tower, 5.5
Air Capacity: 990 m 3 /s per tower
Not water streams: Tower No. 1 —
Tower No. 2 —
RECARBONATION
— 19 in; depth of packing = 7.6 in
in 3 /m 2 -min
in diameter, 2
(3000 m 3 /m 3 )
0.50 m 3 /s cool 46°C to 26°C
0.69 m 3 /s cool 50°C to 30°C
Number: 2 (3 compartment basins: 1st stage recarbonation, intermediate
settling, 2nd stage recarbonation)
Detention Time, 1st and 2nd stage recarbonation: 15 minutes each
Overflow rate, intermediate settling: 5 m 3 /m 3 —h @ 0.66 in 3 /s
FILTRATION
Number of filters: 4
Dimensions: 6.7 in x 7.3 in
Type: open, gravity, mixed media
Hydraulic loading rate: 0.2 m 3 /in 2 —min @ 0.66 m 3 /s
Maximum operating head loss: 3 in
Filter aids: alum and polymers
Backwash system: Hydraulic with rotating surface wash arms
Backwash rate — 0.6 m 3 /m 2 —Inin
Surface wash rate — 0.024 m 3 /m 2 —inin
Backwash water receiving tank volume: 705 in 3
ACTIVATED CARBON ADSORPTION
Number of contactors: 17
Normal Service: 16 in parallel operation, 1 for carbon storage and
standby service
Type: Upflow, countercurrent, in steel pressure vessels
Dimensions: Overall height — 12.5 in; Sidewall height — 7.3 in;
Diameter — 3.7 in 3
Contact Time: 34 minutes at 0.66 in Is
Carbon Size: 8 x 30 mesh
Carbon Weight: 35 Mg per contactor (660 Mg total)
speed electric motors
67
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TABLE A—i. (continued)
CHLORINATION
Number of contact basins: 1
In—line feeding and mixing
Contact Time: 30 minutes
Chlorine Feeders: 3 (900 kg/day each)
On site generation of chlorine: 900 kg/day
CHEMICAL SLUDGE TREATMENT AND RECOVERY SYSTEMS
Sludge Pumps
Number: 3 3
Capacity: 0.032 to 0.044 in /s
Influent solids capability: 5% maximum
Sludge Thickener
Number: 1
Dimensions: 14 in diameter, 2.5 in sidewater depth
Loading: 24 m 3 /rn 2 -d @ 1.5% solids from clarifier at flow of 0.66 m 3 /s
dry solids loading = 15 kg/m 3 —h
Thickened sludge concentration: 8 to 15% solids
Thickened Sludge Pumps
Number: 3
Capacity: 5 liter/rn at 18 in head each, variable speed
Influent solids capability: 18% maximum
Centrifuges
Number: 2
Capacity: 900 kg/hour each
Feed Rate: 3 to 6.6 liters/rn
Recalcining Furnace
Number: 1,6 hearth
Dimensions: 6.8 in OD; 6.1 in ID
Capacity: 0.1 to 0.5 kg/s dry CaO
Scrubber: 3 stage jet impingement
Fuel: natural gas with propane standby
Lime Storage Bins
Number: 2
Capacity: 32 Mg each
Dimensions: 3.8 in diameter by 4.6 m storage depth (overall height =
8.7 in)
Carbon Dioxide Compressors
Number: 3 3
Capacity: 0.76 in /s (12% C0 2 ) each
68
-------
TABLE A—i. (continued)
ACTIVATED CARBON REGENERATION
Regeneration Furnace
Number of furnaces: 1, 6 hearth
Dimensions: 2.8 m OD; 2.1 m ID
Capacity: 0.01 to 0.063 kg/s (dry basis)
Steam Addition: No. 4 and No. 6 hearths (optional); 1 kg steam per
kg carbon
Air Pollution Control:
Fuel: natural gas with propane standby
Scrubber: Venturi followed by water separator
Afterburner: Vertical, refractory lined steel, 760°C at 0.5 seconds
minimum gas retention time
Carbon Wash and Transfer Tanks
Number: 2
Dimensions: l.5nidiameter by 3 in high
Equipped with bag dump and dust collector
Regenerated Carbon Wash Tanks
Number: 2
Dimension: 1.5 m diameter by 3 m high
Spent Carbon Dewatering Tanks
Number: 2 (open top)
Dimensions: 1.5 m x 1.5 m x 4.4 in high
Furnace feed system: 0.3 m diameter screw conveyor, stainless steel
with capacity of 0.01 to 0.063 kg/s on a
dry basis
Carbon Slurry Pumps (transfer carbon from regeneration furnace to
carbon wash tanks)
Number:
Type: Diaphragm slurry, air operated, 7.6 cm suction and discharge
Capacity: 0.03 m Is max. with 4:1 turndown ratio
69
-------
SCALE
CHLORINATOR
I NHIBITOR
FEEDER
PRETREATME
0 TRANSFER
PUMPS
ACID
STORAGE
TANK
CLEANING
TANK
SOLUT ION
FLUSH
TANK
FLUSH
PUMPS
CLEANING
PUMPS
HIGH PRESSURE
FEED PUMPS
BLOWER
DECAR BONATOR
PRODUCT
PUMPS
z
Ill
-4
0
ACID ACID ACID ACID
TRANSFER DAY INJECTION DILUITON
PUMPS TANK PUMPS PUMPS
I
Figure A—i. Reverse Osmosis Plant Flow Diagram.
-------
APPENDIX B
SUMMARY ANALYSES FOR GENERAL CONSTITUENTS, TRACE INORGANICS,
RADIOACTIVITY AND PESTICIDES*
Table Number Page
B—i Summary Analyses for General Constituents,
January through June 1976 72
B—2 Summary Analyses for General Constituents,
October 1976 through June 1977 . 74
B—3 Summary Analyses for General Constituents,
January 1976 through June 1977 (Entire Period of Study). 77
Summary Analyses for Trace Inorganics,
January through June 1976 80
B—5 Summary Analyses for Trace Inorganics
October 1976 through June 1977 82
B—6 Summary Analyses for Trace Inorganics,
January 1976 through June 1977 (Entire Period of Study). 84
B—7 Radioactivity Analysis at Q9 . . 86
B—8 Pesticide Analyses 87
*
Description of sample locations referred to in tables are as follows:
Qi, Influent; Q2, Clarifier Effluent; Q4, Ammonia Tower Effluent; Q6, Filter
Effluent; Q 8 , Activated—Carbon Effluent; Q9, Chlorine Contact Basin Effluent;
Q21A, Reverse Osmosis Influent; and Q21B, Reverse Osmosis Effluent.
71
-------
TABLE B-i. SUMMARY ANALYSES FOR GENERAL CONSTITUENTS
January through June 1976
Constituent and
Parameter
Location*
Qi
Q2
Q4
Q6
Q8
Q9
Ca, mg/i
Mean 102 142 107
Std. dev. 10 29 23
Range 72—134 98—253 85—268
No. samples 90 90 87
Mg, mg/i
Mean 25 1,0
Std. dev. 1.5 1.0
Range 20—29 0.1—5
No. samples 70 68
Na, mg/i
Mean 209 205
Std. dev. 19 19
Range 178—284 173—261
No. samples 70 68
NU 3 —N, mg/i
Mean 43 19
Std. dev. 10 5
Range 2 7—100 10—36
No. samples 84 75
Ci, mg/i
Mean 231 246
Std. dev. 20 23
Range 201—311 158—306
No. samples 90 87
SO 4 , mg/i
Mean 284 312
Std. dev. 45 39
Range 219—403 238—408
No. samples 90 87
Alkalinity, mg/i
Mean 306 137
Std. dev. 35 26
Range 206—460
No. sampies 89 86
B, mg/i
Mean 0.63
Std. dev. 0.14
Range 0.3—1.1
No. samples 85
TABLE B-i continued
72
-------
TABLE B—i (continued)
Constituent and
Parameter
Location*
—
Qi
Q2
Q 4
Q6
Q8
Q9
F, mg/i
Mean 0.64
Std. dev. 0.16
Range 0.3—1
No. samples 86
P0 4 —P, mg/i
Mean 5.2 0.09
Std. dev. 1.2 0.17
Range 0—8 0.00—1.3
No. samples 90 90
EC, pS/cm
Mean 1870 1470
Std. dev. 160 130
Range 1270—254( 980—1820
No. samples 85 82
pH
Mean 7.6 11.4 6.7
Std. dev. 0.1 0.1 0.15
Range 7.4—8.1 11.2—11.7 6.3—7.2
No. samples 87 87 83
Turbidity, TIJ
Mean 24 1.9 0.85
Std. dev. 8 1.6 0.38
Range 0—45 0—13 0—3
No. samples 89 89 86
COD, mg/i
Mean 108 53 45 13
Std. dev. 16 7 7 8
Range 78—144 23—69 25—67 2—52
No. samples 78 80 87 238
TOC, mg/i
Mean 15 7.3
Std. dev. 4 2.6
Range 8—31 3.5—20
No. samples 82 238
Org—N, mg/i
Mean 1.6 1.1 0.6
Std. dev. 0.8 0.8 0.4
Range 0.5—5.3 0.2—4.8 0.2—2.6
No. samples 86 86 80
*
Sample Locations: Qi, Influent; Q2, Clarifier Effluent; Q 4 , Ammonia Tower
Effluent; Q6, Filter Effluent; Q8, Activated—Carbon Effluent; and Q9,
Chlorine Contact Basin Effluent.
73
-------
TAILE B—2. STM(ARY ANALYSES FOR GENERAL CONSTITUENTS
October 1976 through June 1977
Constituent
and Parameter
Location*
_______
Qi
Q2
Q6
Q8
Q9
Q21A
Q21B
Ca, lug/i
Mean 110
Std. dev. 22
Range 59—148
No. samples 37
Mg, mg/i
Mean 24 0.2
Std. dev. 2 0.1
Range 20—28 0.1—0.2
No. samples 34 35
Na, mg/i
Mean 218 210 14
Std. dev. 31 27 6
Range 165—264 81—263 8—27
No. samples 34 113 114
NH 3 —N, mg/i
Mean 45 37 3.3
Std. dev. 15 12 2.9
Range 18—138 13—85 0.0—14
No. samples 153 153 152
Cl, mg/i
Mean 258 277 18
Std. dev. 82 37 6
Range 191—737 179—523 10—42
No. samples 35 119 120
SO 4 , mg/i
Mean 248 1
Std. dev. 63 2
Range 150—500 <1—22
Alkalinity,
mg/i CaCO 3
Mean 116
Std. dev. 49
Range 27—330
No. samples 156
B, mg/i
Mean 1.0 0.84
Std. dev. 0.2 0.21
Range 0.7—1.8 0.1—1.6
No. samples 34 34
TABLE B—2 continued
74
-------
TABLE B—2 (continued)
Constituent
and Parameter-
Location *
Qi
Q2
Q8
Q9
Q21A
Q21B
F, mg/i
Mean
Std. dev.
Range
No. samples
P0 4 —P, iug/l
Mean 5.6 0.07
Std. dev. 0.8 0.04
Range 4—9 0.00—0.25
No. samples 156 155
TDS, mg/i
Mean 1020
Std. dev. 100
Range 860—126(
No. samples 51
EC, US/cm
Mean 1850 2070 1530 88
Std. dev. 280 240 200 36
Range 230—270( 1500—3100 620—l95( 37—230
No. samples 177 179 108 118
pH
Mean 7.5 11.5
Std. dev. 0.2 0.2
Range 6.5—7.9 11.6—11.9
No. samples 165 183
Turbidity, TU
Mean 42 1.1
Std. dev. 14 0.5
Range 19—95 0.1—4
No. samples 161 115
COD, mg/i
Mean 142 52 18 24 1.8
Std. dev. 37 11 7 7 14 15
Range 89—272 109—160 31—78 4—51 4—69 <1—9
No. samples 160 160 160 159 118 .119
TOC, mg/i
Mean 13.8 6.7
Std. dev. 2.9 2.2
Range 0.5—28 2.5—14
No. samples 111 117
TABLE B-2 continued
75
-------
TABLE B—2 (continued)
Constituent
and Parameter
Location *
Qi
Q2 Q6
Q8
Q9
Q21A
Q21B
Org—N, rag/i
Mean
8.3
3.9
1.26
Std. dev.
2.0
1.5
0.48
.
Range
5—23
1.7—10
0.0—3.8
No. samples
157
157
156
Phenol, ig/l
Mean
Std. dev.
Range
No. samples
CN,
Mean
Std. dev.
Range
No. samples
MBAS, rag/i
Mean
Std. dev.
Range
No. samples
*
Sample Locations: Qi, Influent; Q2, Clarifier Effluent; Q6, Filter Ef flu-
ent; Q8, Activated—Carbon Effluent; Q9, Chlorine Contact Basin Effluent;
Q21A, Reverse Osmosis Influent; and Q21B, Reverse Osmosis Effluent.
76
-------
TABLE B-3. SUMMARY ANALYSES FOR GENERAL CONSTITUENTS
January 1976 through June 1977 (Entire Period of Study)
Constituent
and Parameter
Location*
Qi
Q2
Q4
Q6
Q8
Ca, mg/i
Mean 104
Std. dev. 15
Range 59—148
No. Samples 127
Mg, mg/i
Mean 25 0.7
Std. dev. 1.7 0.9
Range 20—29 0.1—5
No. samples 104 103
Na, mg/i
Mean 212
Std. dev. 24
Range 165—284
No. samples 104
NH 3 —N, mg/i
Mean 39
Std. dev. 12
Range 13—100
No. samples 237
Cl, mg/i
Mean 239
Std. dev. 48
Range 191—737
No. samples 125
SO 4 , mg/i
Mean
Std. dev.
Range
No. samples
Aikalinity, mg/i
Mean
Std. dev.
Range
No. samples
B, mg/i
Mean
Std. dev.
Range
No. samples
TABLE B-3 continued
77
-------
TABLE B—3 (continued)
Constituent
and Parameter
Location *
Qi
Q2
Q4
Q6
Q8
F, mg/i
Mean
Std. dev.
Range
No. samples
P0 4 —P, mg/i
Mean
Std. dev.
Range
No. samples
TDS, mg/i
Mean
Std. dev.
Range
No. samples
EC, iS/cm
Mean
Std. dev.
Range
No. samples
pH
Mean
Std. dev.
Range
No. samples
Turbidity, TIJ
Mean
Std. dev.
Range
No. samples
COD, mg/i
Mean
Std. dev.
Range
No. samples
TOC, mg/i
Mean
Std. dev.
Range
No. samples
515
1.0
0—9
246
1860
250
1230—2700
262
7.5
0.2
6.5—8.1
252
36
15
0—95
250
131
35
78—272
238
0.08
0.11
0.0—1.3
245
11.5
0.2
11.2—11.7
270
1.4
1.2
0—13
204
52
10
20—109
240
45
7
25—78
247
14
3
0.5—31
193
15
8
2—52
397
7.1
2.5
2.5—20
355
TABLE B-3 continued
78
-------
TABLE B—3 (continued)
Constituent
and Parameter
Location *
Ql
Q2
Q4
Q6
Q8
Org—N, mg/i
Mean
5.9
2.9
Std. dev.
3.6
1.9
Range
0.5—23
0.2—10
No. samples
243
243
Phenol, pg/i
Mean
Std. dev.
Range
No. samples
CN
Mean
Std. dev.
Range
No. samples
MBAS, mg/i
Mean
Std. dev.
Range
No. samples
*
Sample Locations: Qi, Influent; Q2, Clarifier Effluent; Q4, Ammonia Tower
Effluent; Q6, Filter Effluent; and Q8, Activated—Carbon Effluent.
79
-------
TABLE B-4. SUMMARY ANALYSES FOR TRACE INORGANICS
January through June 1976
Constituent
and Parameter
Location*
Qi
Q2
Q6
Q8
As, pg/i
Mean 2.5 1.1 1.1 1.1
Std. dev. 1.1 0.7 0.4 0.3
Range 1—5.5 0—2.8 0.7—2.8 0.5—2.5
No. samples 74 74 71 76
Ba, pg/i
Mean 81 41 32 33
Std. dev. 21 22 22 23
Range 33—134 20—120 8—93 11—97
No. samples 74 74 71 76
Cd, pg/i
Mean 9 2.9 2.5 2.2
Std. dev. 6 1.7 1.6 1.8
Range 4—30 0.7—10 0.7—8 0.6—7.8
No. samples 74 74 71 76
Cr, pg/i
Mean 192 88 84 48
Std. dev. 86 51 45 32
Range 76—582 16—289 16—228 3—128
No. samples 74 74 71 76
Cu, pg/i
Mean 285 93 88 27
Std. dev. 67 28 24 14
Range 152—436 29—172 32—164 5—80
No. samples 74 74 71 76
Fe, pg/i
Mean 179 17 40 45
Std. dev. 68 ii 25 67
Range 58—398 6—53 15—185 18—309
No. samples 74 74 71 76
Ebb, pg/i
Mean 40 23 22 26
Std. dev. 77 39 31 32
Range 10—650 6—359 6—213 6—174
No. samples 74 74 71 76
In, pg/i
Mean 35 1.5 2.3 4.1
Std. dev. 10 1.5 1.1 1.4
Range 14—75 0.3—9 0.6—9 1.5—9
No. samples 74 74 71 76
TABLE B—4 continued
80
-------
TABLE B-4 (continued)
Constituent
and Parameter
Lo
cation*
Q2
Q6
Q8
Hg, Pg/i
Mean
1.2
0.9
1.2
4.9
Std. dev.
3.4
2.2
3.2
21
Range
No. samples
0.1—20
54
0.1—15
54
0.1—16
51
0.2—168
56
Se, pg/i
Mean
6.2
6.5
6.3
6.4
Std. dev.
2.9
3.5
3.3
3.5
Range
No. samples
2—13
74
2—17
74
2—14
72
2—22
76
Ag, pg/i
Mean
13
8
12
14
Std. dev.
52
33
64
58
Range
2—423
1—234
0.3—516
0.0—457
No. samples
57
57
54
59
Zn, pg/i
Mean
300
29
670
124
Std. dev.
210
84
320
72
Range
No. samples
140—1930
74
5—740
74
150—2400
71
12—536
76
*
Sample Locations: Qi, Infiuent; Q2, Clarifier Effluent; Q6, Filter Ef—
fluent; and Q8, Activated—Carbon Effluent.
81
-------
TABLE B—5. SUMMARY ANALYSES FOR TRACE INORGANICS
October 1976 through June 1977
*
Constituent
Location
and
Parameter
.
Qi
Q2
Q6
Q8
As, pg/i
Mean 3.3 2.5 1.8 2.4
Std. dev. 1.2 1.7 1.2 1.8
Range 1.5—5.0 0.0—5.0 0.0—5.0 0.0—5.0
No. samples 27 27 27 27
Ba, pg/i
Mean 81 36 31 31
Std. day. 26 21 19 22
Range 40—177 15—114 10—97 12—114
No. samples 26 26 26 26
Cd, jig/i
Mean 29 2.4 1.8 1.7
Std. dev. 16 1.6 1.0 1.7
Range 12—97 0.3—8.4 0.3—5.4 0.3—9.8
No. samples 32 32 32 32
Cr, jig/i
Mean 154 37 41 26
Std. dev. 76 25 39 24
Range 62—490 9—111 8—219 4—112
No. samples 33 33 33 33
Cu, pg/i
Mean 266 73 49 32
Std. dev. 87 25 34 15
Range 130—470 19—112 3—114 6—69
No. samples 27 27 27 27
Fe, pg/i
Mean 325 40 207 66
Std. dev. 156 45 275 77
Range 51—779 4—216 12—1520 12—449
No. samples 33 33 33 33
Pb, pg/i
Mean 19 3.6 8.0 5.3
Std. dev. ii. 2.5 15.5 12.5
Range 3—62 0.6—11 0.2—71 0.1—72
No. samples 26 26 26 27
Mn, pg/i
Mean 35 4.4 6.2 4.9
Std. dev. 13 9.2 7.5 4.4
Range 9—98 0.2—45 0.3—34 0.3—26
No. samples 33 33 33 33
TABLE B—S continued
82
-------
TABLE B—5 (continued)
Constituent
and Parameter
Location *
Qi
Q2
Q6
Q8
Hg, pg/i
Mean
9
2.6
3.6
6.7
Std. dev.
30
2.0
7.7
13.8
Range
0.1—177
0.7—11
0.6—46
0.3—57
No. samples
26
20
26
13
Se, pg/i
Mean
<2.5
<2.5
<2.5
<2.5
Std. dev.
Range
<2.5
<2.5
<2.5
<2.5
No. samples
30
33
33
33
Ag, pg/i
Mean
5.5
0.8
13
1.5
Std. dev.
1.4
0.6
1.6
2.8
Range
1.8—8
0.1—2.3
0.0—7.2
0.0—15
No. samples
21
16
21
21
Zn, pg/i
Mean
380
239
412
162
Std. dev.
130
105
328
78
Range
130—830
20—512
70—1980
20—304
No. samples
27
17
27
23
*
Sample Locations: Ql, Influent; Q2, Clarifier Effluent; Q6, Filter Ef-
fluent; and Q8, Activated—Carbon Effluent.
83
-------
TABLE B—6. SUMMARY ANALYSES FOR TRACE ENORGANICS
January 1976 through June 1977 (Entire Period of Study)
Constituent
and Paran ter
Location*
Qi
Q2
Q4
Q6
Q8
As, pg/i
Mean 2.7 1.5 1.3 1.4
Std. dev. 1.2 1.2 0.8 1.1
Range 1—5.5 0.0—5 0.0—5 0.0—5
No. samples 101 101 98 103
Ba, pg/i
Mean 81 40 32 32
Std. dev. 22 22 21 23
Range 33—177 15—120 8—97 11—114
No. samples 100 100 97 102
Cd, pg/i
Mean 15 2.7 2.3 2.1
Std. dev. 14 1.7 1.5 1.8
Range 4—97 0.3—10 0.3—8 0.3—9.8
No. samples 106 106 103 108
Cr, pg/i
Mean 180 72 70 41
Std. dev. 85 50 47 31
Range 62—582 9—289 8—228 3—128
No. samples 107 107 104 109
Cu, pg/i
Mean 280 88 77 28
Std. dev. 73 29 32 14
Range 130—470 19—172 3—164 5—80
No. samples 101 101 98 103
Fe, pg/i
Mean 224 24 93 121
Std. dev. 123 28 173 79
Range 51—779 4—216 12—1520 12—449
No. samples 107 107 104 109
Pb, pg/i
Mean 35 18 18 21
Std. dev. 67 35 28 30
Range 3—650 1—359 0.2—213 0.1—174
No. samples 100 100 97 103
Mn, pg/i
Mean 35 2.4 3.5 4.3
Std. dev. ii 5.4 4.7 2.7
Range 9—98 0.2—4.5 0.3—34 0.3—26
No. samples 107 107 104 109
TABLE B-6 continued
84
-------
TABLE B—6 (continu’ d)
Constituent
and Parameter
. *
Location
Q2
Q4
Q6
Q 8
Hg, pg/i
Mean
4
1.2
2.0
5
Std. dev.
17
2.3
5.2
20
Range
0.1—177
0.1—15
0.1—46
0.2—168
No. samples
80
74
77
69
Se, pg/i
Mean
5
5
5
5
Std.dev.
3
3
3
3
Range
<2—13
<2—17
<2—14
<2—22
No. samples
104
107
105
109
Ag, pg/i
Mean
11
6
9
10
Std. dev.
44
29
54
50
Range
2—423
0.1—234
0—516
0—457
No. samples
78
73
75
80
Zn, pg/i
Mean
321
68
600
133
Std. dev.
195
120
340
75
Range
130—193(
5—740
50—2400
12—536
No. samples
101
91
98
99
*
Sample Locations: Qi, Influent; Q2, Clarifier Effluent; Q4, Ammonia Tower
Effluent; Q6, Filter Effluent; and Q8, Activated—Carbon Effluent.
85
-------
TABLE B-7. RADIOACTIVITY ANALYSIS OF EFFLUENT (Q9)
Sample
Date
Gross Alpha Activity
pci/i
Gross Beta Activity
pCi/i
Jan. 31,
1976
0.6 ± 1.5
28 ± 8
Feb. 5
0.0 ± 1.2
28 ± 8
Feb. 9
0.6 ± 1.9
25 ± 11
Feb. 26
0.3 ± 1.3
22 ± 10
Mar. 4
0.0 ± 1.8
20 ± 10
Mar. 11
0.0 ± 1.6
22 ± 10
Apr. 15
0.0 ± 0.5
29 ± 9
Apr. 22
0.1 ± 1.0
20 ± 9
Apr. 29
0.0 ± 0.4
28 ± 10
May6
0.5±0.9
41±10
May13
0.0±0.8
40±11
May20
0.1±0.9
42±11
June3
0.0±0.5
31±11
June17
0.7±2.0
38±11
June24
2.2±1.8
23±11
Julyl
0.0±0.5
44±11
July15
0.6±1.0
50±9
July 22
0.1 ± 0.8
51 ± 10
Oct. 14
0.0 ± 1.8
49 ± 19
Oct. 21
0.0 ± 2.0
63 ± 20
86
-------
TABLE B—8. PESTICIDE ANALYSES
Pesticides Evaluated and Concentration Limit:
Concentration above which
pesticide not found in any
Pesticide sample, pg/i
BHC 0.01
Lindane 0.01
Heptachior 0.01
Aidrin 0.01
DDE 0.01
Dieidrin 0.01
Endrin 0.01
DDT 0.1
Methoxychior 0.1
Number and Location of Samples Analyzed for Pesticides:
Sampling Period Qi Q2 Q6 Q9
January through June 1976 3 1 9
October 1976 through June 1977 10 10 8 19
87
-------
TECHNICAL REPORT DATA
(Flease read Jias.tructions on the reverse before completing)
1. REPORT NO. 2.
EPA—600/2—78—076
3. REcIPIENT’S ACCESSIO #NO.
4. TITLE AND SUBTITLE
WATER FACTORY 21: RECLAIMED WATER, VOLATILE ORGANICS,
VIRUS, AND TREATMENT PERFORMANCE
5. REPORT DATE
June 1978 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Perry L. McCarty, Martin Reinhard, Carla Dolce,
Huong_Nguyen,_and_David_G._Argo
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Civil Engineering
Stanford University
Stanford, California 94305
10. PROGRAM ELEMENT NO.
1BC611
1L O OIITnAOT/GRANTNO.
EPA—S—803873
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory-—Cin.,OH
Office of Research and Development
US. Environmental Protection Agency
cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Pre—final 1—76 to 6—77
14,SPONSORING AGENCY CODE
EPA—600—14
15. SUPPLEMENTARY NOTES
Project Officer: John N. English 513/684—7613
16.ABSTKACT
This report describes the performance of Water Factory 21, a 0.66 m 3 /s advanced
wastewater treatment plant designed to reclaim secondary effluent from a municipal
wastewater treatment plant so that it can be used for injection and recharge of a
groundwater system. Included in this evaluation of the first one and one—half
years of performance are summary data for general inorganics, heavy metals, virus,
and a broad range of organic materials. Processes included in the plant are lime
treatment, ammonia stripping, breakpoint chlorination, filtration, activated—carbon
adsorption, reverse osmosis, and final chlorination. The performance of individual
processes as well as overall efficiency was evaluated.
17. KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIEIERS/OPEN ENDED TERMS
C. COSATI Field/Group
Waste Treatment Treatment
Water Reclamation
Nutrients
Viruses
Organic Compounds
Potable Water
Microorganisms
Reuse
Heavy Metals
Haloforms
Trihalomethanes
Advanced Was tewater
13B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
100
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9.73)
88
. U. S. G0V RNEIIT P INTIN 0FFICE 1978—757—140/1345 Regon No. 5-I l
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