UPGRADING WASTEWATER STABILIZATION
PONDS TO MEET NEW DISCHARGE STANDARDS
SYMPOSIUM PROCEEDINGS
Editors:
E. Joe Middlebrooks
Donna H. Falkenborg
Ronald F. Lewis
Donald J. Ehreth
PRWG1S9-1
Utah Water Research Laboratory
College of Engineering
Utah State University
Logan, Utah 84322
November 1974
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UPGRADING WASTEWATER STABILIZATION PONDS TO MEET
NEW DISCHARGE STANDARDS
Proceedings of a
Symposium held at Utah State University
Logan, Utah
August 21-23, 1974
Edited by
E. Joe Middlebrooks
Donna H. Falkenborg
Ronald F. Lewis
Donald J. Ehreth
Sponsored by
Utah Water Research Laboratory
and the
Division of Environmental Engineering
College of Engineering
Utah State University
Logan, Utah
and the
Office of Research and Development
Environmental Protection Agency
National Environmental Research Center
Cincinnati, Ohio
and the
Municipal Pollution Control Division
Washington, D.C.
Utah Water Research Laboratory
College of Engineering
Utah State University
Logan, Utah 84322
November 1974 PRWG1S9-1
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ACKNOWLEDGMENTS
This publication and the Symposium were partially supported by Grant Number R-803294-
01-0 received from the National Environmental Research Center, Environmental Protection
Agency, Cincinnati, Ohio.
The great expenditure of time and effort made by the Symposium participants and authors
of the papers is gratefully acknowledged. Without such willingness to share knowledge and
experiences, meetings such as this would be impossible.
E. Joe Middlebrooks
Dean
College of Engineering
Utah State University
iii
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TABLE OF CONTENTS
Page
INTRODUCTORY REMARKS
W. A. Rosenkranz 1
REVIEW OF EPA RESEARCH AND DEVELOPMENT LAGOON UPGRADING PROGRAM
FOR FISCAL YEARS 1973, 1974, and 1975
R. F. Lewis 3
STATE OF THE ART OF LAGOON WASTEWATER TREATMENT
R. E. McKinney 15
CONSTRUCTION PROCEDURES AND REVIEW OF PLANS AND GRANT
APPLICATIONS
W.R.Uhte 21
POLISHING LAGOON EFFLUENTS WITH SUBMERGED ROCK FILTERS
W.J. O'Brien 31
STABILIZATION POND UPGRADING WITH INTERMITTENT SAND FILTERS
E. J. Middlebrooks and G. R. Marshall 47
INTERMITTENT SAND FILTRATION TO UPGRADE LAGOON EFFLUENTS-
PRELIMINARY REPORT
J. H. Reynolds, S. E. Harris, D. Hill, D. S. Filip, and E. J. Middlebrooks 71
PERFORMANCE OF RAW WASTE STABILIZATION LAGOONS IN MICHIGAN
WITH LONG PERIOD STORAGE BEFORE DISCHARGE
D. M. Pierce 89
SEPARATION OF ALGAE CELLS FROM WASTEWATER LAGOON EFFLUENTS
R. A. Gearheart and E. J. Middlebrooks 137
UPGRADING LAGOON TREATMENT WITH LAND APPLICATION
R. E. Thomas 183
LAGOON EFFLUENT SOLIDS CONTROL BY BIOLOGICAL HARVESTING
V/.R. Duffer 187
PROGRESS REPORT: BLUE SPRINGS LAGOON STUDY, BLUE SPRINGS,
MISSOURI
CM. WalterandS. L. Bugbee 191
COST-EFFECTIVENESS ANALYSIS FOR WATER POLLUTION CONTROL
R. Smith 199
NOTES
Research on Cold Climate Wastewater Lagoons
H. J. Coutts .227
Polishing Gravel and Activated Carbon Filter on Aerated Lagoon Effluents
G. Hartmann 229
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TABLE OF CONTENTS (Continued)
Page
MEMBERS OF THE SYMPOSIUM 231
APPENDIX 233
AUTHOR INDEX 237
SUBJECT INDEX 241
VI
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INTRODUCTORY REMARKS AT THE EPA/ORD INTRA-AGENCY
WORKSHOP ON WASTEWATER TREATMENT PONDS
W. A. Rosenkranzl
In June of 1973, Region X sent a letter to
consulting engineers, municipal officials, agencies,
and others concerned with Water Pollution Control.
That letter contained the following statement:
"It is generally recognized that neither standard
oxidation lagoons nor aerated lagoons by themselves
will be able to achieve the required level of treatment.
Therefore, this region will not be able to approve
construction grants for projects proposing lagoons as
the method of wastewater treatment unless such
lagoons are part of a system designed to preclude any
discharge or which incorporates supplemental treat-
ment components capable of improving the effluent
quality to an acceptable level. Meeting our minimum
treatment requirements might be achieved by com-
bining the lagoon treatment with an irrigation ef-
fluent disposal system, by adding supplemental treat-
ment components or by constructing a non-overflow
lagoon."
A report prepared for the Office of Research
and Development by George Barsom of Ryckman,
Edgerley, Tomlinson, and Associates, Inc., entitled
"Lagoon Performance and the State of Lagoon
Technology" had an overall negative viewpoint as to
the suitability of lagoons for secondary treatment and
repeatedly cited the lack of hard performance data on
lagoons. The data contained in the report gave no
assurance that there were existing lagoon designs
capable of meeting the secondary treatment
standards.
On behalf of the Office of Research and
Development of the Environmental Protection
Agency (EPA), I wish to welcome you to the
Intra-Agency Workshop on Wastewater Treatment
Pond Upgrading Technology. You are a select group
of EPA staff and state officials brought together to
review the Office of Research and Development's
program for upgrading wastewater treatment ponds.
Before you leave, we intend to pass on to you the
most recent results of our on-going research pro-
grams, and program plan for the future. The results of
*W. A. Rosenkranz is Director, Municipal Pollution
Control Division, Office of Research and Development,
Environmental Protection Agency, Washington, D.C.
the workshop should provide you with solutions to
the problems posed by Region X and Mr. Barsom.
The question as to whether lagoons, as they
now exist, meet the new secondary treatment
standards and what methods would work to upgrade
lagoon treatment in cases where they presently do
not meet the standards is of high priority for many
Regional Offices of EPA. This is because nearly 90
percent of the wastewater lagoons in the United
States are located in small communities of 5,000
people or less. These communities, many with an
average daily wastewater flow of only 175,000 to
200,000 gallons, do not have the resources to keep
operators at the treatment sites throughout the day.
EPA, in my view, has a definite responsibility in
this area. The agency has defined secondary treat-
ment, obviously with the knowledge of the numbers
of treatment ponds that exist, and knowing that
effluent quality from the ponds is questionable. I also
clearly recall that, in the early days of the construc-
tion grant program, the regions spent considerable
effort in convincing state agencies that treatment
ponds were a viable treatment process. If there can be
developed economical upgrading techniques which
can save the sunk capital costs, we owe that to the
communities with ponds. A high degree of technical
knowledge is usually lacking in the operators from
these communities. Often, only periodic inspection or
maintenance is carried out by the community's work
force. Therefore, the development of relatively inex-
pensive methods for upgrading lagoons that do not
require sophisticated and constant operation or ex-
tensive maintenance is urgently needed.
The majority of the research needs identified
this year by our regional offices pertaining to
biological treatment are concerned with lagoon up-
grading, particularly algal removal from lagoon ef-
fluents. As you may be aware, three pilot-scale
research contracts are currently in progress to evalu-
ate removal of algae from lagoon effluents.
The projects and technology to be discussed
during this seminar were planned to have a quick
payoff because it is felt that they can be completed
in time to impact the July 1, 1977, federal deadline
for achievement of secondary treatment in all
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Rosenkranz
municipal installations. The projects funded at Utah
State University, which are the intermittent sand
filter and land application of algae laden effluents,
and at the University of Kar>,oi, ue submerged rocx
filter, offer good potential for cost effective upgrac,-
ing technology.
We feel thai our research program plan will
identify the inadequacies of facultative and aerated
lagoons. Recommended practices for disinfecting
lagoon effluents are needed, whether we are consider-
ing inherent destruction of coliforms (natural die-off
relative to detention time), chlorination, or other
disinfection processes. Work is also planned on
control of nutrients. The broad objective is the
development and demonstration of technology which
can be recommended in your respective regions as
cost effective for upgrading applications.
Prior to today's assembly, there were at least
two major symposia held to disseminate information
on wastewater treatment pond technology, and
several EPA Technology Transfer Seminars to dis-
seminate upgrading technology to consulting engi-
neers. This conference differs from the make-up of
previous seminars and symposia in that investigators
engaged in research activities have been brought
together with regulatory personnel and those engaged
in approving treatment plant design to discuss current
research, design, and operational findings of waste-
water treatment ponds.
The workshop agenda contains topics including
the basic biology of the treatment mechanism, algal
removal process evaluations, disinfection technology,
and cost effective analysis. We look forward to
reviewing any special problem confronting your
specific region. While we may not have all the answers
to these problems, we must make our R&D program
responsive to your needs. An assembly such as this is
a useful mechanism to that end.
In the next two and one-half days, we will
recap past experience and discuss on-going projects in
detail. You will be informed of our R&D program
plan, which was prepared to delineate the course of
action and tentative resource allocations to produce
an array of upgrading technologies. Unfortunately,
our declining budget situation has precluded alloca-
ting resources as originally proposed, but we will
attempt to optimize our investment to ensure
maximum utilization of resources to produce the
results required. Consequently, our demonstration
sites will not span all temperature zones, waste
compositions, etc., but sites representative of the
broadest spectrum of conditions possible will be
selected.
As a result of specific problems in Region X,
personnel from the Advanced Waste Treatment Re-
search Laboratory in Cincinnati, Ohio, and R&D
Headquarters met with the regional staff to discuss
specifics of their policy statement and the R&D
program plan. Based on those conversations, it was
concluded that the research program of improving
effluents of wastewater treatment ponds would be
responsive 10 Region X's needs. However, it was also
concluded that the output from the program would
be available in design-manual form too late. Region X
staff urged us to prepare an interim report on
whatever methodology was available. It was readily
apparent that regional offices need whatever data are
available as quickly as possible so that they can be
better prepared to ensure that the requirements of
the FWPCA Amendment of 1972 would be satisfied
with regard to evaluation of cost effective alter-
natives.
Mr. John Rhett, Deputy Assistant Administra-
tor for Water Program Operations, repeated the
regions' request for interim data from our upgrading
program. It became imperative that an interim report
on R&D's program be prepared. We know of no
better way to provide you with that interim report
than to gather together as we are now doing. Your
needs were the catalyst that precipitated the events
leading up to this workshop.
As a result of your requests and input, we have
adjusted our program plan. Due to reduced research
budget resources, we are constrained in our participa-
tion in the construction phases of demonstration
projects. We are in a position where we must rely on
you to assist us in putting together demonstration
projects with joint R&D-construction grant funding.
Your assistance is required to optimize our R&D
dollars. You will continue to have a direct hand in
planning future research in this field. Either before
you leave, or when you return to your respective
regions, we want your recommendations for future
development and/or demonstration projects.
Before closing I'd like to mention two other
factors which 'will-or should-impact our R&D. This
first is recognition of new technologies that may
impact pond design and performance. Such things as
pressure and vacuum sewer systems may change the
volume and character of raw wastes. The other factor
is that, while we are attempting to upgrade ponds to
secondary levels, many are or will be located on water
quality limited streams, requiring best practicable
treatment above secondary. Let's not repeat our past
mistakes and ignore future technology and/or ad-
ministrative actions which could further impact the
use of treatment ponds.
We intend to be directly responsive to your
needs and hope that the information passed on to
you during the course of the workshop will satisfy
your most immediate requirements. Perhaps this
meeting will set the stage for future meetings of
similar nature. If you have suggestions for improving
the substance or format we would like to have them.
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REVIEW OF EPA RESEARCH AND DEVELOPMENT LAGOON
UPGRADING PROGRAM FOR FISCAL YEARS 1973,1974, AND 1975
R.F.Lewis1
Introduction
This paper will review the Environmental
Protection Agency Research and Development Pro-
gram for upgrading the performance of lagoon waste-
water treatment systems. Specifically, those lagoon
projects initiated in fiscal years 1973 and 1974 and
those planned for fiscal year 1975 will be discussed.
In developing an upgrading program for any
widely used wastewater treatment process, it is
important to consider the types of communities
served by that process, the personnel and financial
resources of those communities, the performance
norm and variability of the process operating in a
conventional non-upgraded mode, and the degree of
effluent quality improvement required to satisfy
pertinent federal and water quality standards. Before
reviewing the fiscal year 1973, 1974, and 1975
projects, these considerations will first be discussed
briefly as related to facultative and aerated lagoons.
The role these factors had in determining the course
and priorities of the EPA research and development
lagoon upgrading program will be emphasized.
Approximately 90 percent of the wastewater
lagoons in the United States are located in small
communities of 10,000 people or less. During the
period of 1940-1974, wastewater lagoons rapidly
gained popularity as a means of treating wastewaters
from isolated industries, such as meat packing plants,
and from small rural communities. A recent report by
Barsom (1973) shows that in 1945 there were 45
lagoons treating municipal wastes, while by 1960 the
number of lagoons had increased to 4,476. To this
number must also be added the many privately
owned lagoons treating wastewaters from motels,
schools, trailer parks, and feed lots that have not been
listed in state or national registers. The proliferation
and acceptance of lagoon treatment for small com-
munities was especially evident in the western and
southern portions of the United States.
1R. F. Lewis is with the National Environmental
Research Center, Advanced Waste Treatment Research
Laboratory, Office of Research and Development, Cincinnati,
Ohio.
For these small communities, lagoons have
proven to be relatively stable treatment.systems able
to handle fairly wide diurnal or daily fluctuations in
wastewater flow and organic loading with negligible
effect on effluent quality. The reason lagoons can
handle these variations is that the long detention
times utilized (10 to 150 days) provide great equaliza-
tion of flow and load. Lagoons generally cost less
than other biological processes to install, and they do
not require around-the-clock surveillance. Main-
tenance work can be performed by the community
work force.
The first lagoons to be used for secondary
treatment were generally single-cell facultative
lagoons. Due to the problems of short circuiting and
poor treatment during cold weather with these early
single-cell systems, multi-cell facultative lagoons,
aerated lagoons, or combinations thereof are specified
by most design engineers today. In certain states,
intermittent-discharge lagoons have also been widely
used in recent years.
Summary of Existing Lagoon Performance
and Characteristic Effluent Quality
A comprehensive analysis of the performance
capabilities of existing lagoons is difficult because of
the lack of consistent, reliable information and
analytical data. Since most lagoons are located in
smaU communities that do not have highly trained
personnel, very few laboratory analyses are
performed on either the influent or effluent from
these lagoons. The Barsom (1973) survey reported
that only 28 of 50 states required routine monitoring
of influent loading parameters. The problems most
often cited by state engineers were offensive odors
(all 50 states), short circuiting (23 states), and algae
carryover problems (21 states).
One of the major obstacles in improving the
application of lagoon technology in the past has been
the failure of engineers to relate lagoon performance
to causative factors, and to modify established design
criteria accordingly. This has created a lack of
confidence in the treatment technique in general, and
a reluctance on the part of regulatory authorities to
endorse new applications of lagoon treatment sys-
tems.
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Lewis
The state-of-the-art report on lagoon
technology by Barsom (1973) is the most comprehen-
sive study of lagoon performance presently available.
Information was assembled during this study by
questionnaires and direct contact of state water
pollution control agencies, municipalities, and in-
dependent researchers. The investigation evaluated
data on lagoon performance from all 50 states and
approximately .3,000 lagoon installations although
Barsom felt that the data were reliable for only about
200 of the lagoons surveyed. Figure 1, taken from
Barsom's report, shows the national average median
effluent values for the BOD and suspended solids of
facultative lagoons, aerated lagoons, oxidation
ditches, and tertiary lagoons. The average median
effluent BOD ranged from 23 to 42 mg/1 and the
average median effluent suspended solids ranged from
37 to 67 mg/1. Figures 2 and 3, also taken from
Barsom's report, indicate the BOD and suspended
solids levels in facultative lagoon effluents in different
geographical areas of the United States, showing the
average median in each area and the range of values
found in that area. For these areas, the average
median effluent BOD and suspended solids ranged
from-25 to 75 mg/1 and from 40 to 540 mg/1,
respectively. For aerated lagoons, Figures 4 and 5,
again taken from Barsom's report, show that the
average median effluent BOD by geographic region
varied from 30 to 80 mg/1, and the average median
effluent suspended solids varied from 60 to 210 mg/1.
TERTIARY
LAGOON
O
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LEGEND
I. Southwest Region
2. South Central Region
3. Southeast Region
4. Ohio Basin
5. Great Lakes Region
6. Missouri Basin
7. Middle Atlantic Region
8. Northeast Region
9. Northwest Region
• Range
• Average Effluent
Median
123456789
TEST LOCATION
Figure 2. Regional average median effluent values
and ranges of values for BOD in facultative
lagoons.
LEGEND
Southwest Region
2. South Central Region
3. Southeast Region
Basin
Great Lakes Region
>uri Basin
7. Middle Atlantic Region
8. Northeast Region
west Region
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Figure 1. National average median effluent values for
BOD and suspended solids.
Average Effluent
Median
12345678
TEST LOCATION
Figure 3. Regional average median effluent values
and ranges of values for suspended solids in
facultative lagoons.
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Review of EPA Research and Development Lagoon Upgrading Program
V.
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r-
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4-
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2.
3.
4.
5.
6.
7.
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9.
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LEGEND
Southwest Region
South Central Region
Southeast Region
Ohio Basin
Great Lakes Region
Missouri Basin
Middle Atlantic Region
Northeast Region
Northwest Region
Range
L
m
Average
Effluent
Median
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TEST LOCATION
8 9
Figure 4. Regional average median effluent values
and ranges of values for BOD in aerated
lagoons.
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Figure 5. Regional average median effluent values and
ranges of values for suspended solids in
aerated lagoons.
Previous Lagoon Projects Sponsored by
EPA or Predecessor Organizations
Over the period of time covering the increased
utilization of lagoons, the EPA and its predecessor
organizations have sponsored several meetings and
research projects on the general topic of wastewater
lagoons and in a few cases on means to upgrade
lagoons. These have included the First and Second
International Symposium for Waste Treatment
Lagoons in 1960 and 1970; the treatment of tanning
wastes by an anaerobic-aerobic lagoon system
(Parker, 1970); a review manual on "Waste Treatment
Lagoons-State-of-the-Art" by McKinney et al.
(1971); a project on "Supplementary Aeration of
Lagoons in Rigorous Climate Areas" (Champlin,
1971); studies on tertiary treatment of lagoon ef-
fluents for phosphorus removal and reuse of the
effluent for a recreational lake (Dryden and Stern,
1968); various studies by the EPA staff at the Arctic
Research Laboratory in Fairbanks, Alaska, on lagoon
treatment in cold climates, including a study on
coarse-bubble diffusers for aerated lagoons in cold
climates (Christiansen, 1973); and the previously
mentioned review of "Lagoon Performance and the
State of Lagoon Technology" by Barsom (1973).
However, this previous involvement at the federal
level lacked overall planning and had no organized
strategy to systematically encourage improved lagoon
design and operation.
Secondary Treatment Standards
The recent promulgation of Secondary Treat-
ment Standards for municipal installations by EPA
(Secondary Treatment Information, 1973) has
provided the necessary stimulus to develop a vigorous
multiple-faceted lagoon upgrading research program.
These regulations which will be effective on July 1,
1977, state that effluent BOD (5-day) and suspended
solids shall not exceed an arithmetic mean value of 30
mg/1 each for effluent samples collected in a period of
30 consecutive days nor shall they exceed 15 percent
of the arithmetic mean of the BOD (5 -day) and
suspended solids values for influent samples collected
at approximately the same times during the same
period (85 percent removal). For effluent samples
collected in a period of 7 consecutive days, the
arithmetic mean of the effluent BOD (5-day) and
suspended solids values shall not exceed 45 mg/1 each.
The geometric mean of the value for fecal coliform
bacteria for effluent samples shall not exceed 200 per
100 milhliters for samples collected in a period of 30
consecutive days nor 400 per 100 milhliters for
samples collected hi a period of 7 consecutive days.
The effluent values for pH shall remain within the
limits of 6.0 to 9.0.
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Lewis
Research Needs Identified for
Lagoon Upgrading Program
The major research needs for wastewater
lagoons identified over the past several years by EPA
regional and headquarters personnel and by a variety
of state, academic, and private groups are summarized
below:
1. Develop and demonstrate low cost suspended
solids and algal removal processes.
2. Establish design guidelines of practice for
lagoon effluent discharge to the land.
3. Establish disinfection guidelines and demon-
strate applicable methods.
4. Develop and demonstrate nutrient control
technology.
5. Characterize the various alternatives of up-
grading lagoons so that construction grant funds can
best be utilized, and that construction grants person-
nel will have assurance that a given design will at least
have the potential of satisfying applicable effluent
standards.
6. Evaluate the utilization of algae to produce a
useful produce either as a direct protein supplement
for animal feed, or as a source of food for biological
predators.
7. Develop and demonstrate methods to con-
trol weeds and other undesirable aquatic growths in
lagoons.
Fiscal Year 1973 Projects
Removal of algae from
lagoon effluents
With the promulgation of the EPA Secondary
Treatment Standards and the publication of the
Barsom (1973) report, attention was suddenly
focused on lagoon treatment technology. It became
evident that a careful and comprehensive reappraisal
of lagoon capabilities and deficiencies was needed to
determine the advisability of new lagoon construction
and potential methods for successfully upgrading the
more than 4,000 existing lagoons to consistent
secondary treatment quality. Methods for solving
many of the operational problems such as offensive
odors were known by engineering firms and consul-
tants who had kept abreast of the continuing evolution
of lagoon designs. This information has been col-
lected and presented at EPA Technology Transfer
Design Seminars and published in a Technology
Transfer Design Seminar handout. One major prob-
lem, however, that seriously affected effluent quality
at least in certain periods of the year in almost all
lagoon systems was the amount of algae contained in
the effluent. These algae settle out in the bottom of a
receiving stream or lake, undergo death and degrada-
tion, and exert a long-term oxygen demand and
oxygen sag. The experimental work at Lancaster,
California (Dryden and Stern, 1968), and research in
South Africa and by the firm of Brown and Caldwell,
Inc., at Stockton, California, showed that for larger
lagoons with skilled operators, tertiary chemical
coagulation followed by sedimentation-filtration or
froth-flotation effectively removed the algae from the
effluent as well as removing phosphorus to low levels.
However, it was felt that less costly and less operator
intensive methods were needed for the smaller com-
munities where personnel are customarily not avail-
able.
A Request for Proposals (RFP) for simple,
reliable, low-cost methods to remove algae and
suspended solids from lagoon effluents elicited a total
of 27 responses proposing a great variety of potential
algal removal techniques. After evaluation by a panel
composed of members of the staff of the Biological
Treatment Section of the Advanced Waste Treatment
Research Laboratory at the National Environmental
Research Center in Cincinnati, three projects were
chosen for funding as being most likely to meet the
criteria set forth in the RFP. They are passage of
lagoon effluent through a slow-rock filter being
studied by Dr. Walter O'Brien at the University of
Kansas, passage of lagoon-effluent through inter-
mittent slow-sand filters, and crop irrigation and land
spreading of lagoon effluents. These latter two
projects were combined into a single research con-
tract to Utah State University. This work is under the
overall guidance of Dr. E. Joe Middlebrooks. The
University of Kansas study is being conducted at the
Eudora, Kansas, lagoon (three cells hi series), and the
Utah State projects are being conducted at the Logan,
Utah, lagoon (seven cells, five in series, the first two
in parallel). Site plans of these two lagoons are
illustrated in Figures 6 and 7, respectively. The details
of these projects are given in other reports presented
at this symposium.
Manual on algae and water pollution
A sole source contract was awarded to Dr. C.
M. Palmer in fiscal year 1973 for a revision and
expansion of his manual "Algae in Water Supplies."
The title and emphasis will be changed with inclusion
of additional color plates, an expanded key for
identification of algae, and new chapters. The new
chapters will discuss Algae and Eutrophication, Algae
and Pollution, Algae as Indicators of Water Quality,
Algae in Streams, and Algae in Sewage Stabilization
Ponds.
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Review of EPA Research and Development Lagoon Upgrading Program
ROCK FILTER EFFLUENT
PUMPED ROCK FILTER INFLUENT
o-
CELL
C
2nd CELL
B
7.8
Ac
PRIMARY I INFLUENT
LAGOON
A
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Figure 6. Flow diagram of Eudora, Kansas, .lagoon treatment system.
ROCK
FILTER
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spreading system
Figure 7. Flow diagram of Logan, Utah, lagoon treatment system.
-------
Lewis
Fiscal Year 1974 Projects
Performance evaluation of existing
facultative lagoons
As was stated earlier, there is a wide variation in
the design of lagoon systems and long-term perfor-
mance data are generally lacking, particularly for
continuous-discharge facultative and aerated lagoons.
Typically, there is no formal test program at most
lagoons, or at best, infrequent grab sampling and
analysis. The EPA Task Force Committee assembled
to prepare a Technical Bulletin on Design Criteria for
Lagoons found little evidence of evaluation of
existing lagoon performance in relation to design.
What data do exist indicate that multiple-cell lagoons
(series or parallel-series operation) perform better
than one large lagoon of equivalent detention time,
and that effluent quality is deteriorated either by
large amounts of algae during summer periods or by
excessive cold and icing over leading to anaerobic
conditions during the winter. It was felt to be of
utmost importance to determine early in the program
whether well-designed, multiple-cell, continuous-
discharge lagoons can meet the 1977 Secondary
Treatment Standards on .a year-round basis without
additional treatment. To accomplish this, it was
decided that a performance evaluation of several
lagoons in different climates and geographical loca-
tions of the country was an essential first step.
Qualified contractors were solicited via an RFP
to submit well-designed facultative and aerated
candidate lagoon systems amenable to rigorous sampl-
ing and analytical evaluation for a period of one year.
Twenty-four hour composite sampling was specified
on a twice-a-week basis except for four periods during
the year (once each season) when sampling was to be
conducted for 30 consecutive days. It was
emphasized that the candidate lagoons should not be
presently over-loaded, and that provisions for
accurate flow measuring (influent and effluent) had
to be assured. Lagoons serving populations greater
than 5,000 were not considered.
Sixteen proposals were received comprising a
total of 39 candidate lagoons. Due to funding
constraints, it was possible to award contacts for
evaluation of only four multi-cell, continuous-
discharge, facultative lagoon systems. The contracts
were awarded to the University of Kansas, Utah State
University, Mississippi State University, and JBF
Scientific Corporation for evaluation of lagoons at
'Eudora, Kansas; Corinne, Utah; Kilmichael,
Mississippi; and Peterborough, New Hampshire,
respectively. All are three-cell series lagoon systems
except Corinne which utilizes seven cells in series.
The locations of these four lagoons are spotted on a
map of the United States in Figure 8. The location of
a similar performance evaluation being conducted by
EPA Region VII personnel at Blue Springs, Missouri,
is also shown in Figure 8. The site plan of the Eudora
lagoon was illustrated previously in Figure 6. Site
plans for the Corinne, Kilmichael, and Peterborough
lagoon systems are given in Figures 9, 10, and 11,
respectively. Information on acreage, average flow,
and organic loadings for the four lagoons being
surveyed by the research and development program is
presented in Table 1. Table 2 summarizes the
sampling and analytical format for the project.
Measurements of daily flow entering and leaving the
lagoon systems will allow the determination of
long-term water balances (accounts for evaporation
and percolation losses). The enumeration of fecal
coliform bacteria in the lagoon effluents will show
whether or not the long detention time in lagoon
systems is sufficient to reduce the numbers to the
levels specified in the secondary treatment standards.
The Peterborough system employs chlorination be-
fore discharge of effluent to the receiving water.
Soluble BOD and COD measurements before and
after chlorination will provide information on the
possible solubilization of organic matter due to lysing
of algal cells arising from the application of chlorine.
Lagoon Workshop Symposium
This symposium is being sponsored with fiscal
year 1974 funds and was planned to accelerate the
exchange of information between the research staffs
conducting experimental work on upgrading lagoon
treatment systems and the EPA and state officials
charged with regulatory and permit activity and
decisions on construction grant applications.
Table 1. System parameters for facultative lagoon
survey.
Site
Peterborough, N.H.
Corinne, Utah
Eudora, Kansas
Kilmichael, Miss.
Total
Acre-
age
20.7
9.5
19.3
8.1
Average
Flow
mgd)
.150*
.070
.120
.110?
Lagoon Loadings
Ob BOD5/day/
acre)
Primary
Cell
4045
35
34
51
Total
Lagoon
15-20
14
13
33
-------
H, N.H.
CORINIS«E,UTAH
/ • L
rKILMICHAEL. MISS
Figure 8. Location of facultative lagoon treatment systems being tested for year-round performance.
-------
10 Lewis
EFFLUENT
INFLUENT
SAMPLING
STATION
Figure 9. Flow diagram of Corinne, Utah wastewater Figure 10. Flow diagram of Kilmichael, Mississippi,
lagoon treatment system. lagoon treatment system.
Table 2. Sampling and analytical guide for performance evaluation of existing facultative lagoons.
Parameter
WWFlow
Daily Total
Type of Sample
Continuous
Min. & Peak
pH
WW Temp.
D.O.
Alkalinity
Total
BOD5a _
Soluble BOD5a
Susp.
Fecal
Solids"
Coliforms
Total CODC
Soluble COD0
Total po
TKNC
NH3-NC
N02-NC
N03-NC
Grab, in-situ
Grab, in-situ
Grab, in-situ
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Lagoon
Influent
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Sample Location
Between
Cells of
Multi-Cell
Lagoons
X
X
X
X
X
X
X
X
X
X
Lagoon
Effluent
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
After
Chlorination
X
X
X
X
X
X
X
X
X
X
X
Algae Cell Count
by Microscope
Composite
X
X
X
"Nitrification inhibited in BOD bottle.
^f LSS and MLVSS analysis (grab) will be performed on the contents of the aerated lagoon.
cAnalyses to be performed in Cincinnati.
-------
Review of EPA Research and Development Lagoon Upgrading Program 11
Pond No. 3
6.5 Ac
FROM
SECONDARY CELL B
OF LOGAN
LAGOON
Pond No. I
8.5 Ac
Pond No. 2
5.7 Ac
INFLUENT-*-
r€FFLUENT
To chlorine contact tank
FROM INTERMITTENT
SLOW-SAND FILTERS
k
-cu
I.
2.
D
cone*
(S) (tonotM tomplt locations for chloriM contact tank
infhJtntt a at attention tlm«« of 15,30, a 45 min.
BC
different d.
Figure 11. Flow diagram of Peterborough, New Ham-
pshire, lagoon treatment system.
Figure 12. Process test sequence for lagoon chlo-
rination study.
Fiscal Year 1975 Projects
Disinfection study (planned)
A scope-of-work has been planned and a con-
tract is being prepared for a chlorine disinfection
study to be carried out by Utah State University at
the Logan, Utah, lagoon. The site plan for the Logan
lagoon system was shown previously in Figure 7.
Effluent to be disinfected can be taken from the
intermittent slow-sand filters, from cell Bj
(secondary cell), or from cell E (final effluent). This
will enable evaluation of a variety of concentrations
of fecal coliform bacteria, algae, and suspended solids
in the effluents to be disinfected. Four experimental
chlorine contact tanks will be constructed with
baffles to control short circuiting. The flow of
effluents through each tank will be precisely con-
trolled. Samples will be analyzed 2 days per week on
tank influents and at the 15-, 30-, and 45-minute
detention points. Three of the chlorination systems
will be operated in parallel with different chlorine
concentrations using effluent from either cell Bj or
cell E as tank feed. The other experimental system
will evaluate chlorination of effluent from the inter-
mittent slow-sand filters. A diagram of the proposed
chlorination experimental layout is presented in
Figure 12. A summary of the sampling and analytical
program for this project is given in Table 3. The
objectives of this comprehensive disinfection project
are to learn more precisely the factors affecting
disinfection of lagoon effluents and the conditions
under which chlorine dosing will release soluble
organics through lysis of algal cells. As can be seen in
the sampling schedule, the die-off of fecal coliforms
from cell to cell of the Lopn lagoon will also be
studied.
Nitrification of lagoon effluent
with a rotating biological
contactor (planned)
Nitrification does not normally occur in facul-
tative lagoon systems because the concentration of
nitrifying bacteria in the upper aerobic zone is not
sufficient for significant oxidation of ammonia nitro-
gen. The numbers of nitrifying bacteria may be low
because of inhibition by the algae or because the
nitrifying bacteria tend to adsorb onto soil particles
and other aggregates and settle out into the anaerobic
zone where they cannot carry out their activities.
Many lagoon treatment systems, thus, may have high
levels of effluent ammonia nitrogen (20 to 30 mg
NH^-N/l) that can seriously interfere with chlorine
disinfection, can exert an oxygen demand in the
receiving waters if nitrification occurs in those waters,
and may be a major cause of eutrophication in
receiving waters.
A scope-of-work has been discussed with the
University of Michigan to conduct a lagoon nitrifica-
-------
12
Lewis
Table 3. Sampling and analytical program for lagoon disinfection project.
Unfiltered-effluent
from Cell B!
FUtered effluent
from Cell Bj before
Chlorination
40! (15 minutes)
4 0, (30 minutes)
4 03 (45 minutes)
Raw Wastewater
Effluent from
Cells Aj & A2
Effluent from
Cells B, & E
Effluent from
Cells C & D
Analyses/day
of sampling
Total
BOD
X
X
X
3
Total
COD
X
X
X
X
7
Sol.
COD
X
X
X
X
X
X
15
Nl^-N
X
X
X
X
X
X
15
Turbidity
X
X
X
X
X
14
Sulfides
X
X
X
X
X
14
TSS
&
vss
X
X
X
X
X
X
15
pH
Temp.
D.O.
X
X
X
X
x
x
12
MPN&
MF
Total
Coliforms
XX
XX
XX
XX
XX
XX
XX
XX
XX
42
MPN&
MF
Fecal
Coliforms
XX
XX
XX
XX
XX
xa
xa
xa
Xs
35
Chlorine
Residual
X
X
X
12
aMPN not required.
6 = mean residence time.
tion grant project at the Genoa, Ohio, waste water
lagoon system. This is a two-cell facultative lagoon as
shown in the site plan in Figure 13. The project will
investigate if it is possible to nitrify the effluent from
a continuous-discharge lagoon using a rotating
biological contactor (RBC) unit (also known as
rotating biological discs or rotating biological sur-
face), and will attempt to quantify seasonal effects. A
six-stage RBC pilot plant will be utilized with 15
4-foot diameter discs in each stage yielding a total of
90 discs. This provides 2,272 sq ft of disc surface area
and with a nominal loading of 2.6 gpd/sq ft will
require a throughput of 5,900 gpd. Pumpage will be
variable over a range down to 0.5 gpd/sq ft. Com-
posite samples of the RBC feed (lagoon effluent) and
after each of the six stages will be collected three
times per week. Analyses to be performed include
organic, ammonia, nitrite and nitrate nitrogen, BOD,
COD, suspended solids, biomass on the discs, pH,
wastewater temperature, and alkalinity. Adjustments
of the flow and organic and ammonia loadings will be
made to optimize the biological response. The effects
of seasonal temperatures on the kinetics of nitrifica-
tion will be observed and the best configuration of
the six stages (series, parallel, or a combination
thereof) defined. The work plan also calls for loading
the system to failure of nitrification and then noting
6.77 Ac
B
6.77 Ac
INFLUENT
EFFLUENT
RBC
PILOT
PLANT
Figure 13. Flow diagram of Genoa, Ohio, lagoon
treatment system.
-------
Review of EPA Research and Development Lagoon Upgrading Program 13
the rate of recovery of nitrification upon the resump-
tion of normal loading.
Hopefully, this project will generate design
criteria for future full-scale work and will eventually
prove the RBC approach to be a simple, reliable
method for nitrification of lagoon effluents.
Combined phosphorus and nitrogen
control in a lagoon (planned)
A joint inhouse/extramural project is being
planned to begin early in calendar year 1975 to
remove phosphorus from and nitrify the effluent of
the St. Charles, Maryland, lagoon. The site plan
shown in Figure 14 indicates this is a six-cell series
lagoon with the first two cells being aerated followed
by four facultative cells. The average flow to this
six-cell system is 0.6 mgd. Equipment installation and
overall project direction will be the responsibility of
the staff of the Joint EPA/District of Columbia Pilot
Plant located several miles away. A service contract
with the Charles County (Maryland) Community
College is being contemplated to provide necessary
day-to-day operation, weekend surveillance, and
analytical work.
EFFLUENT
INFLUENT
SURFACE
AERATOR
Figure 14. Flow diagram of St. Charles lagoon treat-
ment system-site of planned nutrient
control project.
Phosphorus removal will be effected by the
addition of alum to different cells of the lagoon
system. Studies will be conducted to determine which
of the first two or three cells is optimal for
phosphorus removal. The rate of sludge buildup at the
bottom of the cells will be followed. The chemical
feed system will be designed to provide good mixing
with cell influent wastewater. A most important
observation will be whether the precipitated
phosphorus sludge tends to settle out in a "clump" or
:venly distributes itself across the cell bottom. This
vill have ramifications concerning the frequency at
vhich the chemical sludge will have to be removed by
'clamming" and also the possible resuspension of
>recipitation phosphorus particles by wind action.
The nitrification studies on the lagoon effluent
will be similar to those planned at Genoa, Ohio, with
the exception that a plastic-media trickling filter pilot
unit will be used instead of an RBC pilot system. The
purpose of the study and parameters to be evaluated
will nearly parallel that work.
This project should aid in the development of
guidelines for design and operation to simultaneously
remove phosphorus and oxidize ammonia nitrogen
for those lagoons faced with both eutrophication and
excessive oxygen depletion in their receiving waters.
Summary of Lagoon Upgrading Projects
A summary of fiscal year 1973,1974, and 1975
research and development sponsored lagoon upgrad-
ing projects and the cost of each project are given in
Tables 4 and 5, respectively. For fiscal year 1975,
lagoon upgrading received the largest share of re-
search and development funds of any of the
biological wastewater treatment processes.
Table 4. Ust of EPA lagoon projects FY 73-75.
1. Algae Removal (FY'73)
A. Intermittent slow-sand filter, Utah State
University
B. Crop irrigation and land spreading, Utah
State University
C. Slow-rock filter, University of Kansas
2. Manual on Algae and Pollution (FY '73), Dr.
Palmer
3. Facultative Lagoon Performance Survey (FY'74)
4. Lagoon Symposium (FY '74)
5. RBC Nitrification Following Lagoon (FY'75
Planned)
6. Phosphorus Precipitation in and Plastic Media
Nitrification Following Lagoon (FY'75 Planned)
7. Lagoon Disinfection (FY'75 Planned)
8. Aerated Lagoon Performance Survey (FY'75
Tentative)
-------
14
Lewis
Table S. Summary of Ord funding for lagoon upgrad-
ing projects.
Description
Amount ($ K)
FY'73 FY'74 FY'75
1. Manual on Algae in 12
Water Pollution
2. Algae Removal Projects 322
3. Facultative Lagoon
Performance Survey
4. Lagoon Symposium
5. RBC Nitrification Follow-
ing Lagoon (Planned)
6. Phosphorus Removal in
and Plastic Media Nitri-
fication Following Lagoon
(Planned)
7. Lagoon Disinfection
Project (Planned)
8. Aerated Lagoon Performance
Survey (Tentative Based on
Availability of Funds)
148
10
70
49
166
105
(350)
TOTALS
334
158 390
(350)
Future Planned Studies
Sufficient funds were not available in fiscal year
1974, nor are they as yet available in fiscal year 1975,
to include well-designed aerated lagoons and aerated/
facultative lagoon combinations in the performance
survey currently beginning on existing facultative
lagoons only. It is hoped that funds will yet be made
available in fiscal year 1975 for this important survey.
If not, the project will be programmed into the fiscal
year 1976 budget. It is anticipated that $350,000 -
400,000 will be required to evaluate four to five such
lagoons for 1-year each.
In future years, it is hoped that studies can be
undertaken to evaluate the use of algae as food
sources for animals or predators. It is probable that
unique designs to limit the predators to certain cells
of a lagoon system will be needed and that the factors
affecting the development of the predators will have
to be understood to develop a successful scheme of
operation. Additionally, to create the necessary
credibility and confidence to convince design engi-
neers to utilize the upgrading techniques currently
being researched, full-scale demonstrations of the
more successful methods of removing algae from the
controlling nutrients in lagoon effluents are planned.
The principal objective of the entire lagoon upgrading
program is to develop design and operating guidelines
to meet a variety of effluent quality needs, and to do
so with an array of upgrading techniques applicable
to the small community nature of lagoon users. Only
in this way can the relative simplicity of operation
and maintenance and the low cost that have made
lagoons such a popular method of wastewater treat-
ment for small communities in the past be retained.
References
Barsom, G. 1973. Lagoon performance and the state of
lagoon technology. EPA Environmental Protection
Technology Series EPA-R-2-73-144. June.
Champlin, R. L. 1971. Supplementary aeration of lagoons in
rigorous climate areas. EPA Water Pollution Control
Research Series 17050 DVO. October.
Christiansen, C. D. 1973. Coarse bubble diffusers for aerated
lagoons in cold climates. EPA Arctic Environmental
Research Laboratory, College, Alaska, Working Paper
No. 17. January.
Dryden, F. D., and G. Stern. 1968. Renovated waste water
creates recreational lake. Environmental Science and
Technology 2:268-278.
McKinney, R. E., J. N. Dornbush, and J. W. Vennes. 1971.
Waste treatment lagoons-state-of-the-art. EPA Water
Pollution Control Research Series 17090 EHX. July.
Parker, C. E. 1970. Anaerobic-aerobic lagoon treatment for
vegetable tanning wastes. EPA Water Pollution Control
Research Series 12120 DIK. December.
Secondary Treatment Information. 1973. Federal Register
38(159):22,298-22,299. Pt. II. August 17.
-------
STATE OF THE ART OF LAGOON
WASTEWATER TREATMENT
R. E. McKinney1
Oxidation ponds have had extensive use in the
United States for the treatment of domestic and
industrial wastewaters from small communities and
isolated industrial plants. The advantages of the
oxidation pond systems lie in their simplicity of
design, construction, and operation. No other waste-
water treatment system is as easy to design, construct,
or operate. In spite of its simplicity, the oxidation
pond system produces a high degree of wastewater
stabilization. In recent years with greater emphasis on
wastewater treatment, some concern has been raised
as to effluent quality produced by oxidation ponds.
With the EPA requirements for secondary treatment
clearly requiring a 30 mg/1 BOD5 and a 30 mg/1
suspended solids for all municipal effluents, the
oxidation pond has been signaled out for its potential
failure to meet these standards. Unfortunately, few
people responsible for enforcement of EPA regula-
tions are concerned about wastewater treatment and
the consequences of eliminating oxidation ponds as
wastewater treatment systems. While oxidation ponds
have been in use for many years, there have been few
documented cases of serious pollution problems
created by the effluent discharged from oxidation
ponds. The reason for this is that oxidation ponds are
essentially small treatment devices that produce a
relatively small discharge. The nature of the BOD and
the suspended solids from oxidation ponds are
different than the discharges from other treatment
devices; but this difference has largely gone un-
noticed. It is time that we recognize that the BODS
and the suspended solids discharged from an oxida-
tion ponds system are definitely different than the
BOD5 and the suspended solids from other treatment
systems. The impact on the receiving waters is
different even though they are measured in the same
units. Unfortunately, there has been a tendency to
lump everything together into a single simple
standard that can be easily administered without any
thinking or understanding of either the problem or its
solution.
1R. E. McKinney is Parker Professor of Civil Engineer-
ing, University of Kansas, Lawrence, Kansas.
Current Design Concepts
The design criteria for oxidation ponds develop-
ed empirically by trial and error. Engineers took the
data from California and Texas and applied it to
other locations throughout the country. They soon
learned that California and Texas were different from
their part of the country and that oxidation ponds
worked differently in different parts of the country.
More was learned from the initial failures than from
the initial successes. Oxidation ponds were built too
small as well as too large. Both systems produced
problems which required further engineering before
solutions were developed. Neither system produced
impossible solutions. As information was developed
through field experience, it was possible to evolve a
sound set of design criteria that fit different parts of
the country.
Unfortunately, little operational data were
generated from oxidation ponds. Oxidation ponds
were too small to require extensive analytical data.
Simplicity of operation eliminated the need for
operators and little data were generated. A few tests
were made periodically that showed that oxidation
ponds performed reasonably well but the data were
limited. When problems occurred, more extensive
sampling was made to confirm that a problem existed
and to base a case for requiring expanded treatment.
Slowly, a large mass of data began to be accumulated
on problem ponds and a question was raised as to
whether or not oxidation ponds should be used for
wastewater treatment. The question is a valid one
which must be answered in both technical and
nontechnical terms. There is a need to know exactly
how oxidation ponds function and exactly what kind
of effluent can be produced on a day in and day out
basis. There is also a need to examine the alternatives
to oxidation ponds and their impact on society if it is
necessary to replace oxidation ponds.
Oxidation ponds are simply large flat holes in
the ground with adequate capacity to hold the
wastewaters for several months. It was found that
oxidation ponds should not be too shallow as weeds
would grow up and create a place for mosquitoes to
grow. At the same time the ponds should not be too
IS
-------
16
McKinney
deep as there has to be adequate surface for algae to
grow and to produce sufficient oxygen to keep the
system aerobic at all times. Experience indicated that
a 4-foot water depth was reasonable for all parts of
the country except the desert southwest where
evaporation required deeper ponds. It was soon
learned that flexibility to control the water depth in
the ponds was also desirable. Often effluent control
structures permitted operation between 3 and 5 feet.
The ponds were drawn down to minimum depth once
cold weather set in and were allowed to rise up to
maximum depth by spring time. In this way the
sewage was actually retained during the low tempera-
ture periods and discharged when maximum flow
conditions existed in the receiving stream.
The size of oxidation ponds was dictated by the
population served with a theoretical volume of
wastewater per capita. In the southwestern part of
the country the rate of evaporation during the
summer dictated the size of the ponds while the
length of winter dictated the size of ponds in
northern climates. For the most part, the initial
ponds were conservatively designed with 120-180 day
retention periods. As results indicated satisfactory
operation, engineers slowly reduced the size of the
ponds down to 90 days and then to 60 days in some
instances. With the reduction in retention time came
an increase in organic load. At 180 days retention the
theoretical design population was 72 people/acre with
a BOD5 load of 12 Ibs/acre/day. The more conveni-
ent design parameter soon became population per
acre since the calculation was made so easily. At 100
people/acre the theoretical retention time became
over 120 days and the load was 17 Ibs BOD,/
acre/day. At 200 people/acre the retention period
was reduced in half and the organic load doubled. As
engineers became more sophisticated, the popula-
tion/acre design criteria was replaced by the BOD /
acre/day loading rate. A 40 Ib BOD5/acre/day loading
rate became popular as the basis of design of
oxidation ponds. Even a 65 Ib BOD5/acre/day loading
rate was employed; but problems began to occur and
the loading rate was reduced. At 65 Ibs BOD,/
acre/day there was an increase in operational prob-
lems and engineers have tended to back off from such
loads even though the literature indicates that opera-
tion as high as 100 Ibs BOD5 /acre/day should be
possible without problems. For the most part engi-
neers have relied more on field evaluations than on
laboratory scale or even pilot scale research studies
over a relatively short period of time. It should be
recognized that no one likes to talk about treatment
systems that fail to operate satisfactorily. For this
reason it has been extremely difficult to obtain data
necessary to develop sound design criteria. Each state
regulatory agency seems to have arbitrarily developed
a set of criteria that they felt comfortable with and
have proceeded to use. For the most part there is
little scientific or technical basis for the design
criteria.
Biological Concepts
In order to properly design oxidation ponds it
is essential to understand the biology and the
biochemistry occurring within the ponds. Over the
years considerable information has been developed on
various aspects of oxidation ponds but seldom has the
information been put together in a usable format for
the design engineer. The net effect has been that the
engineer has simply followed the state health depart-
ment design criteria without any regard to the results
obtained. Too often, if problems resulted, the engi-
neer was quick to point out that the system followed
state design criteria and the problem was not his
responsibility.
Initially, the biochemical reactions were
thought to be a simple set of symbiotic reactions
between the bacteria and the algae. The bacteria
aerobically stabilized the organic matter in the
wastewaters to carbon dioxide and converted it back
to oxygen which the bacteria needed for their aerobic
reaction. All that was needed was time for the
bacteria to metabolize the organic matter and ade-
quate surface for the algae to obtain enough light for
their metabolic reactions. The simple symbiotic reac-
tion was not as simple as it seemed at first. The
bacterial reaction was one of synthesis, followed by
endogenous respiration. The synthesis reaction re-
quires oxygen for the metabolism of the organic
matter to form new cell mass, carbon dioxide, water,
and ammonia. The following reaction is representa-
tive of the metabolism of domestic sewage by
bacteria in a mixed culture environment. Only the
biodegradable fraction of the domestic sewage is used
in this equation.
Synthesis:
C7.1 H12.6 °3.0N + 3'° °2 -* C5H9°3N + 2A C02
+ 1.8H20
With a normal domestic sewage having 200 mg/1
BOD5, 112 mg/1 oxygen would be required to
stabilize the organic matter in the sewage and 154
mg/1 VSS as microbial solids would be created. These
micfobial solids are unstable organic matter and
continue to undergo aerobic degradation via
endogenous respiration as follows:
Endogenous Respiration:
C5H9O3N + 4 02 — 0.2 C5H903N
= 4C02+0.8NH3 + 2.4H20
-------
State of the Art of Lagoon Wastewater Treatment
17
The endogenous respiration reaction results in the
production of 30 mg/1 inert organic solids as dead
microbial cells while using 150 mg/1 oxygen and
releasing 13 mg/1 ammonia nitrogen and 206 mg/1
carbon dioxide. The inert organic solids are still
suspended solids that settle very slowly since they
were individual bacteria cells. The empirical formula-
tion used in the above equations was C^gC^N
instead of the more classical CjHyC^N. The reason
for this is that a number of studies over the past 20
years have indicated that C5H9O3N is the more
correct value. The most recent study was made at the
University of Kansas this past year and produced
extensive data on the validity of the C5H^03N value.
These equations show the two basic bacterial
metabolism reactions at completion but give no
information about the degree of completion and the
time required to reach the completion of each phase.
An oxidation pond system is not a concentrated
biological reactor like a trickling filter or activated
sludge, but rather is a dispersed biological reactor like
the BOD bottle. Under aerobic conditions the
bacteria will complete the synthesis reaction in 24 to
48 hours and the endogenous respiration reaction in
an additional 18 days. From a practical point of view
over 99+ percent of the metabolizable organic matter
in the domestic sewage will have been metabolized at
the end of the synthesis phase. If the bacteria were
not dispersed, they could be quickly separated with
the production of a high quality effluent. In most
oxidation ponds the bacteria metabolism will be
complete with the production of 30 mg/1 VSS and
about 15 mg/1 inorganic SS, 314 mg/1 carbon dioxide,
and 13 mg/1 ammonia nitrogen while demanding 262
mg/1 oxygen.
The metabolism of the organic matter dispersed
in the domestic sewage results in a relatively clear
liquid containing considerable carbon dioxide,
ammonia nitrogen, and phosphates. In the presence
of light energy the algae are able to convert these
elements into new cells by a synthesis reaction similar
to the bacterial synthesis reaction.
Synthesis:
Algae,
>C,Hq(X,
593
Unfortunately, the algae reverse the stabilization
reaction and take stable materials and convert them
back to unstable organic compounds in the form of
algal protoplasm. If the 314 mg/1 carbon dioxide
produced by the bacterial metabolism reactions were
all metabolized by the algae, 20 mg/1 ammonia
nitrogen would be required to synthesize 187 mg/1
VSS as algal cells and 229 mg/1 oxygen would be
released. If the reactions stopped there, it would be a
standoff with all the organic matter being converted
from domestic wastewater organics to bacteria and
algal cell mass. The oxygen demand by the bacteria
would exceed the oxygen production by the algae,
262 mg/1 oxygen demand in contrast to 229 mg/1
oxygen production. If an additional source of oxygen
were not readily available, the oxidation pond could
not remain aerobic. There is also another factor that
has to be considered. The algae cells are unstable
organic matter the same as bacteria cells and also
undergo endogenous respiration.
Endogenous Respiration:
C5H903N + 4 02^ 0.2 C5H903N + 4 C02
+ 0.8NH3 + H20
The endogenous respiration reaction of the algae is
exactly the same as the endogenous respiration
reaction of the bacteria. Approximately 37 mg/1 of
dead algal cells will remain as inert VSS with 19 mg/1
inorganic suspended solids. The oxygen demand
would be 183 mg/1 with 16 mg/1 ammonia nitrogen
released. The overall reaction would result in a
combined suspended solids production of 67 mg/1
VSS and an oxygen deficit of 216 mg/1 from a
wastewater having an initial BODS of 200 mg/1. If the
reactions stopped here there would be a serious
problem. Fortunately the reactions continue.
Algae undergo endogenous respiration like
bacteria; but with the release of carbon dioxide, new
algal cells are produced as long as there is sunlight
available for metabolism. The net effect is that the
algae recycle their carbon from active protoplasm to
gas back to active protoplasm with a small fragment,
approximately 20 percent, being shunted off to inert
volatile organic suspended solids. The two reactions
occur simultaneously and pass almost unnoticed.
During the dark period algae demand oxygen the
same as bacteria and synthesis must wait until light is
available.
The cycling between synthesis-endogenous
respiration and back to synthesis is not enough to
keep the system aerobic nor will it solve the balance
between the bacteria and the algae. Something more
is needed. That something more is the alkalinity that
exists in the sewage. The alkalinity forms a source of
carbon for the algae to grow, as shown below.
Alkalinity:
5 Na2CQ3 + 5 62
2 H20
The production of oxygen requires the conversion of
inorganic carbon to organic carbon. If 300, mg/1
alkalinity as CaCC>3 were present in the domestic
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18
McKinney
wastewaters, the algae would convert half of it to
the carbonate form and raise the pH while producing
79 mg/1 VSS and 96 mg/1 oxygen. Unfortunately the
additional oxygen is produced at the expense of
additional organic matter. The combination of
organic metabolism, alkalinity, and time permits the
oxidation pond to produce the oxygen needed for
waste stabilization. For the oxidation pond to have a
net gain in oxygen, it is necessary for the algae to
recycle the carbon through several cycles to create
inert organic solids that are not oxidized in the
oxidation pond. With domestic sewage as used in the
previous equations, the minimum balanced retention
period would be 160 days. Fortunately, sedi-
mentation of both orgafiic solids in the raw wastes
and algae has resulted in balanced operations at 90 to
100 days retention instead of 160 days.
The key to successful production of quality
effluents from oxidation ponds lies in algal removal.
Most of the efforts to reduce the algae in the
effluents from oxidation ponds have centered on
effluent structures drawing off the effluent from
below the pond surface. Since light is critical for the
algae, the motile algae tend to predominate over the
nonmotile forms in oxidation ponds and migrate to
the desired level near the pond surface. The
predominant nonmotile algae tend to have a high
surface area to mass ratio so that they easily remain
dispersed when agitated slightly. Wind action over the
surface of oxidation ponds tends to keep the non-
motile algae suspended while the motile algae have no
difficulty remaining suspended. The nonmotile algae
settle slowly and eventually are removed by sedi-
mentation where wind action is minimal. The use of
multiple series ponds results in decreasing algal
concentrations where submerged pipes are used be-
tween ponds. In effect, the algae retention time is
increased over the liquid retention time. Un-
fortunately, the effluent quality from multiple cell
oxidation pond systems is not satisfactory unless the
retention period is quite long, 120-180 days, or unless
mixing action is minimized. Recent studies on algal
removal from oxidation pond effluents center on
rock filtration and sand filtration. It is hoped that
information will be forthcoming to demonstrate the
validity of these techniques.
Coliform Reductions
In addition to BOD and SS reductions, EPA
regulations require coliform reductions to 200 fecal
coliforms per 100 ml. The reduction in fecal coli-
forms follows normal die-off relationships. There are
no antibiotics or toxic materials produced in the
oxidation ponds that reduce the fecal coliforms. The
only factors affecting fecal coliforms are starvation
and predation. The lack of sufficient organic matter
results in starvation of the fecal coliforms while
certain protozoa and crustaceans act as predators on
the fecal coliforms the same as on the other bacteria
in oxidation ponds. Overall, it appears that multicell
ponds will be needed with a total retention period
between 60 and 100 days to meet EPA effluent
requirements without chlorination. Mixing by wind
action in single cell ponds will permit short circuiting
and make it all but impossible to meet effluent
criteria without chlorination.
Microbiology of Oxidation Ponds
While an understanding of microbiology is not
essential to the design of oxidation ponds it does help
understand the reactions which occur and the changes
that take place during the different seasons of the
year. The primary bacteria in oxidation ponds appear
to be Achromobacter, Pseudomonas, and
Flavobacterium and coliforms. All of the bacteria
grow quickly until the organic matter is stabilized and
then die off as a result of simple starvation.
The algae which grow in oxidation ponds are
related to the chemical quality of the system. For the
most part the motile flagellated algae predominate
since they can easily move to the optimum light level.
Chlamydomonas, Euglena, Chlorogonium, Phacus,
Pandorina, and Carteria are the major green
flagellated algae predominating in oxidation ponds.
The predominant green nonflagellated algae include
Chlorella, Ankistrodesmus Microactinium,
Scenedesmus, Acttnastrum,_ and Closterium. All of
these algae except Chlorella have sharp projections
that maximize surface area per unit mass and are able
to survive in the presence of predators. Filamentous
algae are predominately blue green algae such as
Oscillatoria, Anabaena, and Phormidium, Anacytis is
also a colonial form of blue green algae found in
oxidation ponds. Navicula is the most common
diatom. The filamentous algae and the colonial algae
survive primarily because animal predators remove
the flagellated algae and Chlorella, leaving these
undesirable forms to predominate.
The free swimming protozoa Paramecium,
Glaucoma, Colpidium, and Euplotes have been ob-
served in oxidation ponds. Vorticella is a common
stalked ciliated protozoa found occasionally. Rotifers
and the crustaceans, Daphnia, Moina, and Cyclops
represent higher animal predators that can quickly
remove the motile green algae and Chlorella. These
large predators metabolize the available algae and
then starve to death, creating a cyclic pattern of
growth, death, and regrowth. The undesirable algae
predominate when the predators reach peak popula-
tion since the predators do not metabolize these
algae. For this reason some ponds become essentially
clear when the crustaceans predominate but other
ponds appear to remain green.
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State of the Art of Lagoon Wastewater Treatment 19
Temperature
Temperature is an important parameter affect-
ing oxidation ponds. Not only does temperature have
a normal effect on the rate of metabolism of the
different groups of microorganisms in the oxidation
pond but it has a special effect when the temperature
changes suddenly. As the temperature changes
normally, the rate of metabolism changes by a factor
of 2 with each 10°C temperature change. In the warm
summer periods, the rate of microbial growth in-
creases for the bacteria, the algae and the higher
animals. As long as the temperature change is
relatively slow, there is no problem. With a sudden
change in temperature, either up or down, there are
short term problems. The reasons for the problems lie
in the differential growth rates of the various micro-
organisms. The bacteria grow the fastest and respond
more quickly to the temperature changes. This means
that the rate of oxygen demand increases faster than
the rate of oxygen supply when the temperature rises.
The algae are larger organisms and respond slower. If
the bacteria respond too rapidly and create excess
turbidity or form black sulfide precipitates, the
growth of the algae is retarded even more and the
adverse impact is extended even further. Recovery
depends upon the growth of the algae and the
production of oxygen. A sudden drop in temperature
can slow the algae down sufficiently that they settle
out before reacting as they should. In the fall a
sudden frost will result in the algae dropping out
because the low temperature is accompanied by less
wind action and more quiescent conditions. The
entire pond becomes quite clear. This is the time that
regulatory authorities recommend drawing down the
pond, since the water quality is at maximum. While
many engineers feel that little action occurs during
the winter period, this is not entirely true. Microbial
reaction continues at a slow rate. The dear oxidation
pond begins to turn green even under an ice cover.
The response is related to light and temperature. By
spring there is a reasonable biological activity but the
melting of the ice cover is generally accompanied by
too rapid a surface temperature increase. The ac-
cumulated organic matter that remained unstabilized
after the long winter period stimulates the rapid
bacteria growth and the unpleasant anaerobic condi-
tions that persist for a few weeks. When the tempera-
ture change is gradual and the ice melting is
accompanied by a lowering temperature, the adverse
conditions are minimized. Like it or not, sudden
temperature changes always bring major changes for
oxidation ponds.
Evaporation
The large surface area of the oxidation ponds
offers a real opportunity for evaporation. In the
eastern part of the United States the rate of rainfall
exceeds the rate of evaporation and actually dilutes
the effluent. As oxidation ponds move westward, the
rate of evaporation equals the rate of rainfall; and
then the rate of evaporation exceeds the rainfall. In
the far west the rate of evaporation exceeds rainfall
many times over and requires a deep pond system
with minimum surface area.
It would seem that a zero discharge system
would be considered the most desirable. There is no
doubt that many small oxidation ponds can be
designed as zero discharge systems with the rate of
evaporation just equal to the rate of inflow. At the
same time, it should be recognized that zero discharge
systems accumulate all the salts and inert solids that
enter the oxidation ponds. Eventually, the zero
discharge system must be abandoned as being unsuit-
able for biological life and returned to the environ-
ment. While such eventuality will be a considerable
period in the future, it must be faced. Overall, the
continuously discharging oxidation pond offers the
best system for pollution control for small com-
munities and industries that require maximum waste-
water treatment with minimum effort.
Design Criteria
Oxidation pond design is still a retention time
problem. Most plants are designed on conventional
concepts but operate at much lower loading rates.
The reasons for this are simply that we tend to
overestimate both the wastewater flow and its BOD5
when we apply a general overall design factor. It is
easy to apply a single factor, and since it is
conservative the engineer continues to use it. Oxida-
tion ponds can play a real role in wastewater
treatment for small systems provided they are proper-
ly designed. It should be recognized that a single
pond system is not satisfactory as it tends to short
circuit both algae and fecal coliforms. A multiceU
oxidation pond system is the only thing that will
produce the desired results. It is important that we
recognize that a three-cell system will probably
provide the best system. A 120-day retention period,
three equal cell system with submerged transfer pipes
should provide an effluent suitable for EPA
secondary treatment requirements. There may be a
few days in the summer when the suspended solids
and BOD in the effluent exceed the 30-30 standards
but the impact on the receiving stream will not be
great enough to warrant serious reaction against the
treatment system. In the late winter 01 early spring
the fecal coliform criteria may be exceeded for a few
days, but once again there is no real evidence that
deviation from the fecal coliform criteria represents
any hazard whatsoever. It is important that standards
reflect real conditions and hypothetical conditions.
Oxidation ponds are simple devices that are
based on sound scientific principles. Oxidation ponds
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20 McKinney
offer no magic solutions or fancy technological
developments. They are economical to build and to
operate. No one wants to collect data on their
operating characteristics. No one wants to accept
responsibility for oxidation ponds. This is a highly
sophisticated era which is more concerned with
technological development than with solving real
problems. It should be recognized that oxidation
ponds can treat wastewaters adequately to meet the
needs of the environment if engineers will use the
knowledge they already have.
The discharge of raw wastewaters to oxidation
ponds results in the discharge of settleable solids that
will readily settle out when the velocity drops below
minimum levels. The initial discharge of wastewaters
should be to a deep section 5 to 10 feet deep and
below the normal floor level of the oxidation pond.
The solids should accumulate around the influent
pipe and create a special anaerobic zone that removes
most of these solid materials from the oxidation pond
reaction. The extra depth in a center section also
results in keeping some of the anaerobic end products
from entering the aerobic zone of reaction. There is
nothing special about shallow oxidation ponds except
where zero discharge ponds are desired or where light
is limiting.
Evaporation is a major factor in oxidation pond
operation and misinterpretation of the operational
data. Evaporation concentrates the residuals and
produces a greater concentration effect than would
have been produced if evaporation had not occurred.
An effluent standard based on concentration alone
fails to consider the influent volume and requires an
effluent quality that is difficult to obtain even with
the most sophisticated system. It is important that we
develop criteria that account for evaporation and
produce the effluent necessary to prevent significant
environmental pollution.
Conclusions
Oxidation ponds have proved over the years to
be one of the most significant forms of economical
wastewater treatment for small communities and
isolated industries. Unfortunately, a lack of under-
standing of the fundamental biochemistry has re-
sulted in considerable criticism of oxidation ponds.
The development of a rigid EPA effluent criteria for
domestic wastewater treatment systems has also
raised a question as to the validity of using oxidation
ponds for wastewater treatment systems. When a
total evaluation is made of all factors involved, it is
apparent that oxidation ponds have a place in
wastewater treatment. With proper design using
multiple ponds and adequate holding time and
properly designed transfer and effluent pipe struc-
tures, oxidation ponds will produce a satisfactory
effluent when consideration is made for evaporation
over such a large surface area. In a few instances the
application of rock filters or slow sand filters may be
necessary to produce a high quality effluent; but a
high quality effluent can be produced on a
continuous basis. The question is not how should
oxidation ponds be used, but rather how can engineers
improve oxidation pond design to meet effluent
criteria and still maintain their economical design and
simplicity of operation.
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CONSTRUCTION PROCEDURES AND REVIEW OF
PLANS AND GRANT APPLICATIONS
W. R. Uhte
\
General Problems with Wastewater
Stabilization Ponds
Before getting down to the nitty-gritty on the
design, construction, and operation considerations
which are involved in federal and state review and
approval of upgrading wastewater stabilization ponds,
let's first discuss some of the general problems usually
connected with such facilities. As most pond installa-
tions are the equivalent of small plants some of the
introductory remarks of Professor George Tchobano-
glous in his paper on "Wastewater Treatment for
Small Communities" given at the Conference on
Rural Environmental Engineering, Warren, Vermont,
September 1973, are directly applicable to this
discussion.
Design
Design of wastewater stabilization ponds for
smaller communities is an area that has not received
the attention it requires or deserves. Many times large
consulting firms will pass up the design of such
facih'ties or assign them to young, inexperienced
engineers. In other cases, small firms with little or no
experience have undertaken the design of these
ponds. Consequently, many of them have now proven
to be inadequate to meet original requirements and
therefore have no chance of meeting the more
stringent discharge requirements established by vari-
ous federal and state agencies. Clearly, the design of
ponds that work, is the responsibility of the engineer
and not the contractor or owner.
It must be pointed out, however, that design
fee schedules and allowable design costs have effec-
tively perpetuated this dilemma. A small complete
wastewater stabilization pond will require just about
the same engineering design effort as a large pond.
Unfortunately most owners and often even the
federal and state regulatory agencies do not recognize
this fact and refuse to accept the high engineering
costs for the smaller units. Technology transfer
information can be helpful, but full recognition of
need for reasonable fees would also upgrade design.
!W. R. Uhte is Project Manager, Brown and CaMwell,
Walnut Creek, California.
Operation and maintenance
Most wastewater stabilization ponds are built
and then practically forgotten. If they are visited
more than once or twice a year the owner complains
that it is a problem installation. Although the more
stringent discharge requirements will be a great
impact on the need for better operation and main-
tenance an even greater impact on manpower require-
ments will result simply from the requirement to
produce continuing operational data. Recently it was
indicated that the effluent monitoring requirements
for a small, less than 1/2 acre, pond installation
amounted to 4 man hours per day. This, of course,
included two men for safety, travel time and the
necessary waiting time between consecutive coliform
samples but not laboratory time. It is probably
typical for the time which will be necessary to meet
the monitoring requirement at most installations.
Once the owner has accepted this situation it
will not be difficult to see that much of the other
routine maintenance around the ponds also receives
attention. Good pond design should include the
selection of equipment which will reduce the work
associated with such operation and maintenance to a
minimum. Such equipment should be well proven,
with adequate service and parts centers available
within reasonable distances in case of breakdowns.
Budget limitations
With water pollution such a topical item it has
been fairly easy lately to convince the voters that
capital improvements to the waste treatment system
are worthwhile. This is especially true with federal
and state participation covering up to 87% percent of
the costs. However, operation and maintenance of the
wastewater stabilization ponds have usually been put
on the welfare side of the budget; i.e., the side which
doesn't produce tangible results such as a library or
city park. Unfortunately this intangible side of the
budget is the first in line when cuts are to be made in
annual expenditures. Often such wastewater facilities
are put on emergency budgeting and only when they
get into trouble with the local pollution control
agency does the owner seriously consider their
budget.
21
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22
Uhte
Probably the greatest challenge to the up-
grading of wastewater stabilization ponds is going to
be in the development of adequate annual operation
and maintenance budgets. These receive no federal or
state aids, will be literally hundreds of times the costs
of existing budgets and will face a long history of
being considered an intangible budget item. Only by
careful evaluation of the grant requirements for
proper operation and maintenance, effluent monitor-
ing and fiscal solvency will this challenge be met. The
following discussions of detail design, construction
and operation considerations must keep in mind the
ever present need to assure that whatever is
accomplished under capital improvements be fully
implemented on a continuing basis.
Design Considerations
As indicated earlier neither the contractor nor
the owner can do much about the design of waste-
water stabilization pond. This task is the responsi-
bility of the design engineer and involves the deter-
mination of safe loading levels, proper pond recircula-
tion and configuration, good inlet and outlet
hydraulics, adequate scum control, safe dike con-
struction, and the correct location and sizing of
ancillary facilities.
Loading levels
Most wastewater stabilization ponds are faculta-
tive ponds having depths between 3 and 8 feet. The
ponds have two active treatment zones: An aerobic
surface layer and an anaerobic bottom layer. Oxygen
for aerobic stabilization in the surface layer is
provided by photosynthesis and surface reaeration,
while the decomposition of the sludge in the bottom
layer takes place anaerobically. The carbon dioxide
given off by the aerobic bacteria degrading organic
wastes in the surface zone and by the anaerobic
bacteria degrading the sludge in the bottom zone is
reused by the surface layer algae to form algal
biomass. This algal biomass produces oxygen to
support the aerobic activity and dead cells which
settle to the bottom and support the anaerobic
activity. Facultative ponds are usually loaded be-
tween 15 and 80 pounds of BOD5 per acre per day,
although special seasonal loadings of up to 1 SO to
175 pounds of BOD5 per acre per day have been
found practical.
Other types of ponds are sometimes utilized for
special purposes. These include high-rate aerobic
ponds, anaerobic ponds, tertiary ponds and aerated
lagoons. High-rate aerobic ponds are usually limited
to applications wishing to produce a maximum algal
biomass, are shallow (12 - 18 inches in depth), and
are usually loaded from 60 to 200 pounds of BOD5
per acre per day. Anaerobic ponds are normally so
heavily loaded that no aerobic zone exists. The entire
pond is devoid of oxygen with loadings usually
ranging from 200 to 1000 pounds per acre per day.
Tertiary ponds are similar to facultative ponds,
however they are usually very lightly loaded (less
than 15 pounds of BOD5 per acre per day) and
therefore minimize the formation of the heavy algal
biomass. They are normally used for polishing ef-
fluents from conventional secondary treatment pro-
cesses. Aerated lagoons derive practically all of the
oxygen for aerobic stabilization from mechanical
means. No algal biomass is formed so photosynthetic
oxygen generation plays no role in the process. Some
surface aeration from natural sources does exist,
however, aerated lagoons cannot be designed based
on surface area loadings. They must be designed
utilizing activated sludge parameters for detention
and oxygenation capacity.
So far only surface loading rates have been
discussed. While these are probably the most useful in
determining pond performance, detention time can
also be effective. Usually with facultative ponds of
reasonable depths (4 to 6 feet) and surface loadings
(50 pounds BODs per acre per day) sufficient
detention times (90 to 100 days) will be achieved.
However, a weak sewage or a system with large
quantities of infiltration or inflow can change this
situation. An existing pond can be upgraded by either
increasing its detention time, decreasing its areal
BOD5 loading or by doing both.
If there is insufficient area for proper pond
expansion the ponds may be deepened to achieve the
necessary detention time and supplemented with
powered mixing and aeration to decrease its areal
loading rate. This supplementation is usually achieved
by installation of either compressed air diffusers or
mechanical aerators. Ponds which require relatively
minor supplemental aeration on a uniform basis
throughout the year usually find compressed air
aeration best. The efficiency of oxygen transfer from
air to process BODS demand is usually less than 8
percent. If the ponds must operate the year around in
a cold climate, then compressed air aeration will
prevent surface freezing and allow direct surface
oxygen transfer to supplement whatever photo-
synthetic activity is available.
When the supplemental requirements are high
(from 20 to 50 percent of natural photosynthetic and
surface activity) or when the requirements are either
seasonal or intermittent, mechanical aerators are
used. Two types of mechanical aerators are available:
Cage aerators and the more common turbine or
propeller vertical-shaft aerators. Mechanical aerators
usually have a BOD5 reduction capacity of between
1.0 and 1.5 pounds BOD 5 per horsepower-hour. The
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Construction Procedures and Review of Plans and Grant Applications 23
vertical-shaft turbine or propeller units are usually
conservatively designed for about 1.15 pounds BOD5
per horsepower-hour and the cage aerators for about
1.3 pounds BOD5 per horsepower-hour.
Cage aerators may be used in relatively shallow
pond depths (4 to 6 feet), and are usually mounted
directly alongside pond dikes. This mounting assures
easy access for maintenance and results in reliable
above water electric power supply. Mixing energy
from the cage aerators seems to have a very large zone
of influence. Surface agitation has been measured on
photographs over 1000 feet from the aerator. When
properly placed near the multiple inlets to a pond the
cage aerators have a tremendous pumping and mixing
capacity.
Vertical shafted turbine or propeller aerators
require greater pond depths (10 to 15 feet) or
specially armoured depressed areas under each unit.
Pond depth is directly related to aerator horsepower
capacity. The units must be mounted within the
ponds, thereby requiring special access walkways or
boat access and underwater cabling for power and
control. Vertical shafted aerators tend to recycle
much of their pumped pond volume and therefore
seem to have less mixing or agitation influence on the
pond surface.
Although the vertical-shafted aerators seem to
cost slightly less initially their maintenance and
operation costs are usually more expensive than cage
aerators. Either type of mechanical aerator may prove
cost effective for any given pond installation. There-
fore, any comparison should be made giving full
consideration of all the facts.
In addition to transferring oxygen to the pond
contents, aeration and its resulting mixing also tends
to break up thermal stratification which often
develops in quiescent ponds. This allows for deeper
penetration of sunlight and increases the growth of
algae, thereby increasing the pond's capacity for
organic loading. Surface agitation from such aeration
also keeps the thin surface layer of slick or scum from
forming and assures maximum photosynthetic rates
and surface aeration.
Wastewater stabilization ponds inherently
provide a cost effective means of treatment for
excessive summer seasonal organic loadings and win-
ter infiltration and inflow hydraulic loadings. Pond
loadings should be conservative to assure this
flexibility. Federal grant personnel should be quick to
recognize these inherent advantages and minimize the
special studies required for the tributary system's
infiltration and inflow status. The volume of buffer
built into a stabilization pond system eliminates the
need for any consideration of shock or diurnal
loading variations.
Pond recirculation and configuration
Upgraded wastewater stabilization ponds
should include provisions for pond recirculation.
Properly designed pond recirculation will involve
recycling from four to eight times the average design
flow into the system. It should be designed to
thoroughly mix the pond contents with the incoming
flow prior to its introduction into the pond(s). This
pre-mixing provides photosynthetic oxygen from the
pond for the immediate satisfaction of the incoming
load, assures a completely mixed environment within
the feed zones of the pond system, helps to prevent
odors and anaerobic conditions within the feed zones,
assists in providing pond mixing and simplifies inlet
and interpond transfer hydraulics.
The transportation of the recycling pond con-
tents should be via open channels whenever possible.
Channels should be of sufficient size to keep
velocities low (under 10 feet per minute) and total
head loss to a minimum (less than H inch) when the
system is being operated at maximum recirculation
rates. Low lift, high capacity irrigation type propeller
pumps usually provide the best efficiencies and
lowest first costs for this type of work, although
non-clog, self-priming centrifugals and Archimedes
screw type pumps are also sometimes used. Regard-
less of the pumps which are used, however, the pump
station should be designed to minimize maintenance
and maximize flexibility. If the pump's intake and
discharge piping is designed to maintain a siphon
condition, pond operating levels can be varied several
feet without affecting the pump's capacity or
efficiency.
Good pond configuration will use all of the
natural and mechanical forces available to achieve full
use of the entire wetted area. Inlets, transfer points,
and outlets should be located to eliminate dead spots
and short circuiting. A proper design will include a
study of the prevailing wind directions and will locate
outlets in those areas of the pond where surface scum
might accumulate. Pond size need not be a limitation
if adequate recirculation, distribution, and orienta-
tion is maintained.
Often the site or process limitations require
multiple pond configurations. This might also result
simply from the necessity of upgrading existing
facilities. Under these conditions recirculation be-
comes even more important. When the multiple
ponds are in a series configuration, the recirculation
reduces the BOD in the mixture entering the first
pond and this assures that the organic load is spread
more evenly throughout all the ponds. This can be an
immediate aid in the reduction of odors, especially
where the first pond has been an anaerobic pond. The
parallel configuration for multiple ponds is even more
effective in reducing pond loadings because its in-
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24
Uhte
fluent is spread evenly across all ponds. In parallel
operation recirculation makes distribution simpler for
it eliminates the limitations of diurnal flow variations.
Probably the most effective multiple pond
configuration with recirculation involves a parallel-
series arrangement whereby the parallel ponds are
loaded as facultative ponds with recirculation and the
final series pond is designed as a natural tertiary unit.
This arrangement allows for the final series pond to
be operated on an intermittent basis for effluent
solids control without affecting the operation of the
recirculation system. It also provides a positive
separation between recirculating pond contents and
the final effluent outlet.
Inlet and outlet hydraulics
Without pond recirculation it is almost impos-
sible to achieve good inlet hydraulics. Such hydraulics
must always be designed for peak wet weather flows
because this is the capacity of the incoming sewer
system. If the influent is pumped into the pond it is
usually easier to achieve the proper inlet hydraulics,
but often this must be at the sacrifice of good
pumping station and upstream sewer system design.
Seasonal and diurnal variations will usually mean that
for a major part of the time gravity flows will be
insufficient to achieve the proper distribution and
mixing velocities for good pond feed conditions or
the sewage will be stored for increasing lengths of
time until sufficient volume has accumulated to
operate the influent pumps at their peak flow rate.
This can result in system septicity and odor produc-
tion.
Although most of the literature indicates that
ponds should be fed by a single pipe near the center
of the pond, this becomes unnecessary when pond
recirculation is employed. A single inlet will not
achieve full utilization of the wetted area of a pond.
Most smaller ponds can utilize multiple entry and
single exit systems and assure full utilization. Large
ponds (over 20 acres) will usually require multiple
inlets and outlets. Even a smaller pond may require
multiple inlets and outlets if its configuration and
orientation cannot be made to take advantage of its
natural flow pattern. When multiple inlet and outlet
pipes are used with a recirculation system, inlet and
outlet hydraulic losses should be maintained at least
ten times the total distribution or collection channel
head loss.
If a system must operate over a large variation
of flow it should be designed to normally provide
good distribution at average daily flow rates and
utilize overflow bypassing weirs for those periods
when it has to handle peak flows. A good single pipe,
multiple port inlet design will result in a 1 foot head
loss at average design flow (port exit velocity approxi-
mately 8 feet per second). The ports of this single
pipe should all be oriented in same direction to
induce a mass movement away from the outlet which
is usually located nearby. A second pipe with low
head overflow weir inlet may be used to accom-
modate peak flows.
Scum control
Probably the greatest operational problem en-
countered with wastewater stabilization ponds in-
volves the control of surface accumulations of scum
and the odors which develop when these accumula-
tions become septic. A good design will eliminate
those areas in which scum normally accumulates and
will make it possible for any scum which is formed to
be recirculated within the system until it is either
degraded aerobically or becomes sufficiently water-
logged to settle to the bottom and decomposes
anaerobically.
Control of scum accumulations is best achieved
by the elimination of all shoreline or aquatic growths,
by proper pond orientation and by the good location
of adequate numbers of pond inlets and outlets.
Weeds and aquatic growths usually are controlled by
periodic spraying, although cutting, sheep grazing and
actual physical removal may also be used. Design
considerations should assure adequate pond depths to
eliminate aquatic growths (usually 4 feet or more)
and sufficient shoreline access to make weed control
easy.
Earlier design considerations have covered the
need for proper pond orientation and the location
and number of inlets and outlets. It should be further
pointed out, however, that proper transfer pipe
design must assure the maintenance of water surface
continuity within the entire recirculation system.
This means that the pipes must be large enough to
limit peak head loss to about 3 to 5 inches with the
pipes flowing about two-thirds to three-quarters full.
By operating these transfer pipes less than full,
unobstructed water surface is maintained between the
supply and return channels and the ponds.
Pond transfer pipes are usually best fabricated
of bitumastic-coated, corrugated-metal pipe with
seepage collars located near the midpoint. This type
of pipe is relatively inexpensive, strong enough to
withstand rough handling and rapid back filling,
flexible enough to allow for the differential settle-
ment often encountered in pond-dike construction,
and sufficiently corrosion resistant to assure long life
under the proposed wet and dry operating conditions.
Expensive isolating control gates are unneces-
sary if each of the transfer pipes are accessible from
the pond and channels by boat. Such gates can be
replaced with specially made fiberglass plugs which
-------
Construction Procedures and Review of Plans and Grant Applications 25
can be used to close the pipes to be taken out of
service. When such a system is used the design
engineer can afford to provide extra transfer inlets
and outlets to assure good distribution and then
throttle their utilization as required. Hydraulic cal-
culations for partially full transfer pipes require quite
a few assumptions, therefore a few extra pipes for
flexibility and operation assurance are often well
justified.
Dike construction
Pond and channel dikes are usually designed
with side slopes between 6 horizontal to 1 vertical
and 2 horizontal to 1 vertical. Normally good pond
soil will support side slopes of 3 horizontal to 1
vertical. However, a proper design will have the
opinion of a qualified soils and foundation engineer
to back up its final decision. Safety considerations
usually require dike freeboards to be at least 2 and
often 3 feet above the pond's peak operating water
level.
Dike slopes not only depend on the material
available for their construction, but also must con-
sider the wind and water-erosion effects and the
protection to be provided. All soils, regardless of
slope, need protection in zones subject to turbulence
and agitation. Such zones can be created by wind
induced wave action, inlet and outlet increased
hydraulic activity and aerator agitation. Whenever
protection is provided around such zones it should
extend several feet beyond the areas involved. Wave
protection should extend 1 foot above and below the
extreme operating water levels.
Erosion protection can be provided by cobbles,
broken or cast-in-place concrete, wooden bulkheads,
or asphalt strips. Whatever is used should recognize
the need to control shoreline and aquatic growths.
The steeper the side slope the less area there is for
such protective coverings and aquatic or shoreline
growths. Larger ponds in windy areas require heavier
erosion protection.
Dike tops should be of sufficient width (10 to
12 feet) to support a 12-inch thick all-weather gravel
road. Road surfaces should be crowned to assure
quick rainwater runoff and minimum dike erosion.
All pond and channel dikes must be provided with
such all-weather access roads so that operating
personnel may conveniently maintain necessary pond
surveillance and control of insects, erosion and plant
growth.
Ancillary facilities
Each pond installation must be provided with
means for easily launching trailer mounted boats into
all water bodies, with means of periodically ascer-
taining the quantity of influent entering the system,
with a method of continuously measuring the
quantity of effluent being discharged from the system
and with portable grab and composite sampling
equipment which can be used to monitor either the
influent or effluent on any required cycle.
Boat launching ramps should be built to pro-
vide'all weather access and good vehicle traction and
support for all parts of the ramp above and at least 3
feet below operating water levels. If the level varies
several feet, the ramp should extend to a sufficient
depth to allow the boat to be launched at the
minimum operating level. Ramps should be construc-
ted of concrete, at least 8 feet in width, and provided
with a 6-inch curb on the outboard edge.
Influent flow measurements should be made
possible by means of pump calibration or manually
read flumes designed to minimize flow turbulence
and interference. If sufficient head is available a
calibrated weir may be used. However, this is a
potential odor hazard if the incoming sewage is
septic. Periodic influent flow checks should be made
to assure that the ponds are not losing flow due to
excess exfiltration and to get some estimate of
evaporation losses.
The continuous effluent flow measuring system
should be designed to provide the most accurate
measurement possible without excessive operation or
maintenance. Proper design should include the use of
accurate V-notch or Cipolletti weirs with simple float
actuated electrically timed recorders. Electric timing
action should be backed up with a spring power
action to assure continuity during power outages. The
flow record must be continuous if effluent quantities,
treatment efficiencies and total receiving water
loadings are to be reasonably determined.
Recent developments in sampler technology
have brought on to the market several portable
samplers capable of gathering both 24-hour com-
posite or grab samples. With or without electric
power available these samplers can provide even the
smallest pond installation with the quality
measurement capability necessary to satisfy all local,
state, and federal water quality requirements. Some
samplers even provide for "dry ice" compartments to
keep the collected samples chilled.
No write-up on ancillary facilities for waste-
water stabilization ponds would be complete without
some mention of housing for operation, maintenance,
and laboratory activities. Certainly the added treat-
ment and monitoring requirements resulting from the
new federal and state regulations will warrant some
type of facility capable of supporting these activities.
Smaller installations may attempt to contract for
these services and therehv honefullv share such
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26
Uhte
facility costs with others. Some may feel that such
facilities are best located in the owner's corporation
yard. Wherever they are, however, they must reflect
the fact that wastewater stabilization ponds are no
longer the type of secondary treatment plant which
can be built and promptly forgotten. They must now
be regularily operated, maintained and monitored.
As a minimum such facilities should contain
operator wash and toilet facilities; proper housing for
plant growth control equipment; access boat and
portable sampling equipment; and compact labora-
tory capabilities. Minimum laboratory tests should
include dissolved oxygen, BOD5, total solids,
suspended solids, volatile solids, and coliform deter-
minations.
Construction Considerations
Once engineering design and local, state, and
federal design reviews have been completed a contract
for the construction of the wastewater stabilization
ponds is put out to competitive bid. In this manner
the owner selects the lowest responsible bidder to
construct the project. Major state and federal
monetary participation dictates that this phase of the
upgrading process receives as much attention as the
design. Many an excellent design has been sacrificed
to loose contract requirements or weak inspection
practices. It is very important therefore that these
aspects of construction receive careful consideration.
Contract requirements
A good contract begins with a proposal which
allows the prospective contractors to clearly under-
stand what they will be obligated to construct and
the rules and regulations which will govern and limit
their construction procedures. A clear and concise set
of drawings and specifications which compliment
each other are the keys to this understanding.
Additional supporting documents often include soils
engineering reports, up-to-date as-built drawings of
existing facilities and horizontal and vertical survey-
ing control data.
Drawings must provide the contractor with
sufficient information to construct all site and struc-
ture improvements in the locations selected. Some-
times on a small contract most of the material quality
requirements can also be set forth on the drawings.
Most of the time, however, these requirements are
reserved for the technical part of the specifications.
Regardless of where they are placed, it is always
important that both documents compliment and not
contradict each other. Contradictions can result in
the contractor providing an inferior product.
In addition to the technical specifications a
good specification document will also provide the
prospective contractor with bidding information,
copies of all bidding and contract forms and docu-
ments and a complete listing of the rules and
regulations governing the project's construction. Bid-
ding information should indicate the routine and
special instructions necessary to the submission of a
responsible bid. This should include instructions on
how the contractor should handle any qualified or
variation bids, contingency allowances and major
equipment listings. Most sewage treatment facility
contracts are best bid as lump sum contracts,
especially when the owner cannot afford the extra
supervisory expense of assuring the accuracy of unit
price quantities. The lump sum contract also makes it
possible to assign the complete responsibility of
constructing an operable facility to the contractor. If
he can prove inadequacy of design to accomplish this,
he of course can relieve himself of this responsibility.
Sometimes after reviewing the contract docu-
ments a contractor will feel that he can accomplish
the same end result by a somewhat different route. If
the contract specification provides a perspective
contractor a means of submitting an acceptable bid
under these circumstances the owner may save
money. A good qualified and variation bid clause will
do just that.
No engineer can anticipate all of the situations
which may develop during construction of a facility.
This is especially true with the upgrading of existing
facilities. A good design will limit these extra work
items to less than 2 to 5 percent of the contract cost,
however, depending on the contract size. To assure
the prospective contractor that such conditions are
going to be expeditiously and properly handled, a
contigency allowance of these approximate amounts
is included within his bid. If the extra work does not
materialize then the money is never spent.
Major equipment listings are a means of assur-
ing that the owner receives his major equipment at
the best price available and that the successful
contractor will not be able to shop around for lower
prices after he has been awarded the contract. When
used, such listings must meet the federal regulations
requiring the listing of two or more acceptable
manufacturers with space for the contractor to
write-in other manufacturer's considered "or equal."
By including all the necessary bond forms and
other contract documents within the contract
specifications the owner eliminates the risk that some
proposed contractor will submit a bid with an
unacceptable guarantee bond or sign a contract and
submit unacceptable material and performance
bonds. It also makes the conditions of bidding and
being allowed to perform completely and equally
clear to every interested contractor.
-------
Construction Procedures and Review of Plans and Grant Applications 27
The rules and regulations governing construc-
tion procedures must be mutually equitable if the
contract is to stand up in any court test. This part of
the contract specifications must be written primarily
for the protection of both parties. Neither the owner
nor the contractor should be required to be deprived
of their basic rights. The owner has a right to expect a
finished product within the time specified which
meets the quality requirements listed. The contractor
in turn has a right to select the method of producing
that finished product within the limits of any listed
restrictions and to be paid for his production in this
manner listed.
Any encroachment by either party into this
basic relationship can weaken its entire premise. The
owner should not have the right to stop work, unless
the contractor is in flagrant breach of contract, and
the contractor must operate within the limits set forth
in the specifications. If the owner feels he is getting
unacceptable quality or if the work is falling behind
schedule he should withhold contract payments, not
shut down or speed up the work or in any other
manner encroach upon the contractor's methods of
operation.
The contractor must also realize that the limits
set forth cannot be exceeded. Two examples of such
limits are the bypassing of existing treatment facilities
and the providing of necessary equipment main-
tenance instruction. Monetary penalties should be
spelled out within the contract specifications for
bypassing with gradation for degrees and times
involved. These penalties should reflect the effect on
the owner's reputation and any possible penalties
imposed by a regulatory agency. They should be
sufficiently expensive to force him to make no
bypassing a major consideration in his methods of
construction. Equipment maintenance instructions
are required prior to the placing of the equipment
into operation and for the proper preparation of
operation and maintenance manuals. To assure their
delivery the contractor should be informed that once
the 75 percent level of completion has been reached
no further progress payments will be made until all
such instructions have been submitted and found
acceptable.
Inspection practices
Often it is assumed by the owner that once the
engineer has completed the design drawings and
specifications he need no longer take an active role in
the completion of the project. This is most often true
of those owners who already have a construction
inspection department overseeing other types of
projects under their jurisdictions. Unfortunately this
is also sometimes quietly accepted by the engineer,
because he realizes that under such an arrangement it
will be far more difficult for the owner to make any
charge of legal liability hold up in court.
To assure that the design engineer accepts his
full responsibility for a project it is necessary for him
to also have the full responsibility for the resident
engineering and inspection of the construction of that
project. The review of shop submittal drawings of
process equipment and piping layouts provides the
design engineer with the final opportunity to visualize
the system's operation and correct any error which
has heretofore escaped detection. In addition, the
continuous involvement of the design engineer assures
that those basic decisions which are often inherent in
a design are also reflected in the quality of the final
construction.
For wastewater stabilization ponds the major
responsibility of inspection will involve the super-
vision of soil compaction as part of the construction
of pond and channel dikes and the assurance that
vertical control (elevation) tolerances are within
contract requirements. Good inspection requires that
an inspector be present whenever the contractor is
doing any work on the project.
Operation Considerations
As major contributors to the cost of the
construction of the upgraded wastewater stabiliza-
tion ponds it seems only natural for federal and state
environmental protection agencies to have a great
interest in their performance. Present federal and
some state regulations already require all grant
supported plants to have an operation and main-
tenance manual prepared by the design engineer, to
require its personnel to take part in operation training
programs, to receive periodic operation performance
evaluations by agency representatives and to have
developed a system of user charges (or equivalent)
sufficient to cover all annual costs, including capital
cost recovery.
Operation and maintenance (O/M) manuals
To be of real value to the operation staff of the
new or upgraded facility the O/M manual must
provide them with a complete description of (1) the
treatment processes involved, including its idio-
syncrasies, and its normal reaction to stress and
seasonal changes; (2) the physical layout, including
hydraulic flow pattern, equipment operation and
monitoring and control devices; (3) process testing,
including laboratory analysis both for control and
monitoring treatment efficiencies and results; (4)
maintenance requirments, including routine preven-
tive and corrective programs; (5) safety restrictions
and precautions; and (6) emergency operation
procedures. The manual must be presented in words
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28
Uhte
and pictures which are understandable to lay person-
nel and should be prepared as soon as practical so
that it is available prior to plant set-up. Some parts of
the write-up could be valuable early in design, but
unless the engineer is assured of adequate remunera-
tion there is little incentive to take the time or make
the effort involved at this stage of the process. Some
form of up-dating should be made after the plant has
operated through a complete seasonal cycle.
Many problems can befall those unwary engi-
neers who assume that this is a simple and relatively
inexpensive task. Unfortunately it is similar to the
design costs previously mentioned, in that small
installations will often require as much or more time
and expense than large installations. If 0/M manuals
are to become the backbone of successful, efficient
operation, their true value and cost must be recog-
nized and accepted by all owners and federal and
state personnel. These costs can amount to sums
which are from 1 to 10 percent of the facilities
construction cost depending on whether the plant is a
major multimillion dollar or a minor hundred
thousand dollar facility. These costs may seem high
when compared to normal design fees, but when
compared to the accumulated annual cost savings a
good manual can accomplish, they become practically
insignificant. Federal and state insistence for quality
manuals and their willingness to share in' the costs of
their preparation is one way they can make it easier
for the owner to meet the annual budget challenge.
Operation training programs
In most instances owners of upgraded waste-
water stabilization ponds will not be able to hire
trained experienced personnel to perform their
plant's necessary operation and maintenance tasks.
Consequently there is, and will continue to be, a great
need for operator training programs. Federal and
state involvement in the development and
implementation of these programs is essential.
On-the-job training with mobile classrooms
provides the most effective programs for the smaller
treatment plants. This is especially true of stabiliza-
tion pond operation. This makes good sense because
of the need to minimize annual budget impacts. Pond
owner budgets do not have room for travel or
away-from-the-job expenses. In addition, in many
cases the treatment process or configuration for
individual plants varies so greatly that the most
efficient training for unskilled lay personnel is to
train them for specific tasks and not general concepts.
Such on-the-job training should incorporate the
use of the plant's 0/M manual as much as possible. In
most instances, if the specific 0/M manual for the
facility was systematically studied and thoroughly
explained to the plant's personnel the training would
meet its goals. Such a review would also provide the
owner with an outside opinion of the adequacy of the
manual, assure its completeness, and present the
federal or state supported trainer with a golden
opportunity for developing favorable public relations
for the whole environmental protection effort.
Performance evaluations
In many areas performance evaluation programs
are just getting started, but already they have raised
questions regarding their ability to gather truly
representative and meaningful data. Certainly plant
performance, housekeeping and maintenance can be
observed and meaningfully recorded. When it comes
to the determinations of operator training and
competency, however, observers must be careful not
to accept at face value any single group's viewpoint.
Data collected during these evaluations must reflect a
consensus of the complete staff. This complicates the
data gathering and probably increases its cost, but
without such meaningfully developed data these
evaluations could easily result in conclusions and
reactions which are completely unverifiable.
Some type of public relations program should
be instigated to assure that all plant personnel are
aware of the performance evaluation program and
what it is set-up to accomplish. Its positive aspects of
determining national, state and local needs and the
importance of sharing of meaningful data should be
emphasized. At no time should the program be
allowed to get the reputation that it's just another
attempt to develop a technique for "big brother to
keep his eye on you."
User charges and self-sufficiency
Federal, and in some cases state, grant regula-
tions already require that grant supported treatment
facilities develop and place into action a program of
user charges, including a capital cost recovery system,
which will assure each system's complete self-
sufficiency upon completion of the present upgrading
program. Revenue program guidelines further
illuminating the restrictions or objectives of this
program have been adopted by several states. If
upgrading of wastewater stabilization ponds is to
achieve its twin goals of improving the discharge from
these ponds and providing the data necessary for the
documentation of these improvements, then each
grant eligible project must have enforced upon itself
the necessary user revenue sharing required for this
self-sufficiency. Complete information on this user
revenue sharing system must be presented to the
voters prior to their being asked to accept the capital
obligation for upgrading.
Although most financial programs will require
the efforts of experts in the public financing field, the
-------
Construction Procedures and Review of Plans and Grant Applications 29
owner and federal and state agencies should insist
that the design engineer also be actively involved.
Preparation of population growth projections, user
participation estimates, capital costs and operation
and maintenance costs are all areas where input from
the engineer is essential.
Summary and Conclusions
Although in many instances this discussion has
spoken of design, construction, and operation con-
siderations in general terms most of the comments
include specific data, techniques, parameters, and
recommendations which when applied judicially to
review and approval programs should provide guide-
lines for judging a project's acceptability. Although it
may seem to be the result of an in-born prejudiced or
misplaced self-esteem, the one theme throughout the
discussion which cannot be ignored is the need for
the complete involvement of the design engineer
throughout all phases of a project's development.
Federal and state regulatory agencies should insist
that owners assure this continuity of involvement and
take advantage of the responsibility it brings.
-------
POLISHING LAGOON EFFLUENTS WITH
SUBMERGED ROCK FILTERS
W. J. O'Brien^
Lagoons have been widely used in the United
States during the past 20 years for the treatment of
wastewater from small municipalities and isolated
industrial plants. Their popularity has been based
upon relatively low first cost, low operation and
maintenance costs, and a high standard of reliability
in producing stabilization of the raw wastewater.
The major flaw with lagoons is the algae which
are often present in the final effluent. These algae can
be removed by a wide variety of coagulation, filtra-
tion, flotation, and oxidation techniques. (See Mc-
Garry, 1970; Tenny et al., 1969; Shindala and
Stewart, 1971; Berry, 1961; Borchardt and O'Melia,
1961; Dodd, 1973; Levin et al., 1962; Parker et al.,
1973; Ort, 1972; Folkman and Wachs, 1973.) How-
ever, the complexity and the cost of operating most
of these processes negate the advantages inherent in
the use of lagoons. Submerged rock filters have the
potential for avoiding these problems.
Preliminary investigation on the use of sub-
merged rock filters for algal removal was conducted
with laboratory scale units by Martin (Martin, 1970;
O'Brien et al., 1973). Additional research with pilot
scale units located outdoors was completed by Martin
and Weller (1973). The findings of these two studies
formed the basis for the field scale trials reported
herein.
Experimental Facilities
The research filters are located at Eudora,
Kansas. The influent for the research pond is ob-
tained from the effluent pipe of the three-cell lagoon
system illustrated in Figure 1. This lagoon system is
very flexible with regard to the sequence of cells
which may be used for treatment. Between June 16,
1973, and February 19, 1974, the facility was
operated with cell 2 as the primary and cell 3 as the
secondary. From February 20, 1974, to the present
time, the system has used cell 1 as the primary, cell 2
as the secondary, and cell 3 for the tertiary treat-
ment.
The sewered population of Eudora is 2,200.
The average daily dry weather sewage flow is approxi-
mately 208 I/capita/day (55 gpcd), however, there is
a large increase in flow during periods of heavy
precipitation. The capacity of the lagoon system,
when operated with a water depth of 1.52 m (5 ft), is
summarized in Table 1. The values given for hydraulic
detention time in Table 1 assume plug flow in each
cell and no water loss occurs from evaporation or
seepage.
Table 1. Physical characteristics of the Eudora waste-
water lagoon system.
Cell Surface Area, Water Volume
Number hectares 106 liters
Time)day&
1
2
3
3.16
1.50
3.17
45.7
21.3
45.9
100
46
100
1\V, J. O'Brien is Professor of Civil Engineering,
University of Kansas, Lawrence, Kansas.
The effluent from cell 3 is collected in a wet
well and pumped through a 102 cm (4 in) diameter
plastic pipe to the research facility. A 5.5 m (18 ft)
length of 15.2 cm (6 in) diameter cast iron pipe is
used to go through the berm of the experimental
lagoon into the inlet structure. The inlet structure
divides the flow into two portions and provides for
the measurement of each portion with a 15° V-notch
weir plate. The lagoon is divided into two parallel
basins by an asphalt coated sheet piling wall. Each
basin contains an influent pond, a rock filter, and an
effluent pond. Flow leaving the experimental facility
is collected in an outlet structure which contains two
parallel channels equipped with stop planks to
control the elevation of the water surface and with
15° V-notch weir plates. Immediately preceding the
stop planks are baffles which protrude 76 cm (30 in)
below the water surface. The purpose of these baffles
is to prevent ice formation in the outlet structure
during the winter and to prevent surface scum from
leaving the ponds during the summer.
The effluent from the experimental lagoon is
collected in a wet well and is pumped back to the
inlet structure of the Eudora lagoon system. Plans of
31
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32
O'Brien
*^v Flow ^ adjustment valve
X ,i sampling
Pump station W\Sampling
for transferring ^location A
lagoon effluent
to filter.
Sampling
location
!|_
location B
Experimental rocK
filter facility
Sampling
location 0
Cell 2
Lagoon influent
structure
Pump ' station to
return filtered
effluent to lagoon
Figure 1. Physical layout of Eudora, Kansas, municipal sewage oxidation pond system and relative location of
experimental rock filter facility (for illustrative purposes only-not drawn to scale).
the experimental lagoon, the inlet structure, and the
outlet structure are shown in Figures 2,3, and 4.
A cross section of the rock filters is given in
Figure 5. The filters are constructed of crushed
limestone having the size gradations listed in Table 2.
Throughout the remainder of this paper the
two filters will be differentiated by designating them
as large rock or small rock.
Both filters are 1.4 m (4.5 ft) high and have 1:3
side slopes. The large rock filter is 5.5 m (18 ft) wide
at the top, 13.7 m (45 ft) wide at the bottom, and
12.5 m (41 ft) long at the top. The small rock filter is
6.1 m (20 ft) wide at the top, 14.3 m (47 ft) wide at
the bottom, and 11.9 m (39 ft) long at the top.
The volume of submerged rock, the volume of
the influent and effluent ponds, and the surface area
of these ponds when the water depth is 1.22 m (4 ft)
are summarized in Table 3.
Each filter also contains three sampling tubes
spaced at 2.7 m (9 ft) intervals across the cross-
sectional axis. These tubes are constructed from 10.2
cm (4 in) diameter plastic pipe and contain 1.27 cm
(.5 in) diameter holes spaced at 7.62 cm (3 in)
intervals. There are four holes located 90° apart at
each interval.
Table 2. Size gradation of the rock used in the two
experimental filters.
Sieve Opening
cm
5.08
3.81
2.54
1.91
1.27
0.95
0.67
0.47
% Weight
Large Rock
7.4
28.8
52.0
10.4
1.3
0.1
Retained
Small Rock
13.4
33.1
39.0
10.4
3.2
0.9
Porosity
0.44
0.44
TableS. Physical dimensions of the experimental
filter system when the water depth is 1.22
meters.
Volume of Influent Pond m3
Surface Area of Influent Pond m2
Volume of Submerged Rock m3
Volume of Effluent Pond m3
Surface area of Effluent Pond m2
Large
Rock
126.5
165.7
126.6
84.3
137.1
Small
Rock
119.4
157.6
142.1
86.1
125.0
-------
Polishing Lagoon Effluents with Submerged Rock Filters 33
Pump Station for Transferring
Lagoon Effluent to Filter
\. Flow Adjustment Valve
X
10.2 cm plastic pipe
It
if
u
u
II
cm
CI Pipe
|! Sampling Location
r Inlet Structure
Vertical
Sampling Tubes
Sampling
Location
C—<
Outlet Structure /
0
i—
6
-4-
9
-1
Scale in Meters
n
u
11 15.2cm
i*/ CI Pipe
n
n
Pump Station to Return Lj
Filter Effluent to Lagoon—*
Figure 2. Plan of experimental rode filter field test facility.
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34
O'Brien
Experimental Program
The experimental lagoon was placed into opera-
tion on January 4, 1974, and completed filling on
January 10.
Starting January 25 three grab samples, taken
between 7 and 12 a.m., have been collected per week
from the effluent of the final cell of the Eudora
lagoon system, the influent to the experimental
lagoon, and the effluent leaving the ponds behind the
large and the small rock filters. These sampling
locations are illustrated in Figures 1 and 2. Samples
were also collected twice weekly from tubes 1,3,4,
and 6 within the filters (see Figure 2) from April 8
through June 24. Tubes 2 and 5 were sampled twice
weekly from May 17 through June 24. All six tubes
were sampled on July 12, 19, and 29.
Prior to April 1, in-place temperature measure-
ments were made with a mercury thermometer. No
dissolved oxygen measurements were taken. Begin-
ning April 1, in situ dissolved oxygen measurements
were made with a portable polarographic membrane
dissolved oxygen probe and temperature measure-
ments were obtained with a resistance wire probe.
The pH of the samples was measured with a labora-
tory pH meter located in the nearby Eudora Water
Treatment Plant.
The samples obtained from the lagoon effluent,
the influent to the experimental lagoon, and the
effluent leaving the ponds behind the large and the
small rock filters were analyzed for total suspended
solids (TSS), volatile suspended solids (VSS), total
and soluble COD, total and soluble BOD5, NH3-
nitrogen, and phosphorus. Chlorophyll analyses were
Top
Stop Plonk Grooves
Aluminum Weir
Side
9 j 2
Scale in feet
Sec. A-A
Baffle
Board
*
Figure 3. Plan of influent structure of the experimental lagoon.
-------
Polishing Lagoon Effluents with Submerged Rock Filters
35
1
1
• 1-
1
• — -
Zl
L|
Stop Plonk Grooves
Aluminum Weir
NBaffle Board
Scale in feet
Sec. B-B
Side
Sec. A-A
Figure 4. Plan of effluent structure of the experimental lagoon.
Stop Plank for Controlling
Voter Level
Walkway
/10.2 cm plastic pipe with
/ 1.27 cm dia. holes spaced
\ at 762cm. intervals.
Four holes at each interval.
•Lagoon Bottom
El. 246.3m
Figure 5. Cross-section of rock filter.
-------
36
O'Brien
also conducted starting with the samples collected on
April 12. Samples obtained from sampling tubes 1
through 6 were tested for TSS, VSS, total and soluble
COD, and chlorophyll. A profile of the in-place
temperature and concentration of dissolved oxygen
was also made in each sampling tube at 0.3 m (1 ft)
intervals.
The procedures used to determine TSS, VSS,
COD, BOD,, and pH followed the methods specified
in the 13th edition of Standard Methods for the
Examination of Water and Wastewater (American
Public Health Association, 1971). However, the mag-
nesium carbonate precoat specified in this method
was not applied to the filter pads. Total phosphorus
was measured by the procedure specified in Methods
for Analysis of Water and Wastes (Environmental
Protection Agency, 1971). Ammonia nitrogen was
measured with a Model 95-10 Orion Ammonia
Electrode connected to a Model 320 Fisher Accumet
pH Meter.
The rate of flow entering and leaving both
experimental filters was measured by determining the
head on each weir with a point gage.
Experimental Results
The hydraulic loading and detention times
within the experimental filter system are summarized
in Table 4. These values assume plug flow through the
filters which probably does not occur because of the
increase in cross-sectional area with depth. Liquid loss
from seepage or evaporation was not considered. The
time periods during which pumping did not occur,
either due to pump malfunction or to the loss of
electrical power, were excluded from the calculations.
This occurred from February 26 through March 2,
from April 22 through April 26, from June 15
through June 17, and from July 14 through July 15.
Monthly summaries of the water quality of the
flow discharged from the Eudora lagoon system, the
flow entering the experimental lagoon, the flow
leaving the pond behind the large rock filter, and the
flow leaving the pond behind the small rock filter are
provided in Tables 5 through 8. In these tables the
water temperature is expressed in °C; TSS, VSS,
COD, BOD5, and dissolved oxygen are expressed in
mg/1 of the parameter; ammonia is expressed in mg/1
as nitrogen; total phosphorus is expressed in mg/1 as
phosphorus; and chlorophyll is expressed in micro-
grams/I as chlorophyll.
The magnitude of the parameters measured in
the samples obtained from the tubes located within
the filters are summarized in Tables 9 and 10. The
value used in preparing these tables was the average
concentration obtained from samples obtained at
four equally spaced depth intervals within each tube.
Changes in the concentration of TSS, VSS, total
and soluble COD and chlorophyll at different depths
in the filters were not significant. The temperature
and the concentration of dissolved oxygen in the
upper 0.3 m (1 ft) of water was usually greater than
that observed in the lower 0.9 m (3 ft).
Discussion
The data presented in Tables 5 and 6 clearly
indicate biological metabolism occurred in the wet
well and pipeline used to transfer the lagoon effluent
to the experimental site. However, the changes which
occurred in the water quality were not large enough
Table 4. Hydraulic loading and detention times within the experimental lagoon system.
Large Rock
Month
February
March
April
May
June
Julv
February
March
April
May
June
July
Influent Pond
Detention
Time, Days
2.7
6.0
2.4
2.0
1.3
3.9
2.7
6.7
2.5
2.1
1.4
4.0
Filter
Hydraulic Loading
1/day/m3
367.4
165.4
418.9
492.9
743.9
257.2
Small
307.8
124.7
339.5
397.6
604.3
210.6
gal/day/ft3
2.7
1.2
3.1
3.7
5.6
1.9
Rock
2.3
0.9
2.5
3.0
4.5
1.6
Detention
Time, Hours
28.7
63.9
25.2
21.4
14.2
41.1
34.3
84.7
31.1
26.6
17.5
50.1
Effluent Pond
Detention
Time, Days
1.8
4.0
1.6
1.4
0.9
2.6
2.0
4.9
1.8
1.5
1.0
2.9
-------
Polishing Lagoon Effluents with Submerged Rock Filters 37
to significantly influence the performance of the
submerged rock filters.
The data in Tables 7 and 8 can be subdivided
into three intervals of time. The first occurred from
the start of operation in January through March 22.
During this period the filters functioned primarily as
sedimentation basins. However, the capture of sus-
pended solids was relatively low because a biological
slime layer had not become completely established on
the surfaces of the rock. Algae which settled in the
upper portions of the filters were therefore re-
suspended in the flow moving through lower portions
of the filter and eventually washed through the
barrier formed by the rocks. This situation was
changed by the development of a biological slime
layer on the rock surfaces which trapped the algae
upon contact. Previous investigations with pilot scale
filters indicate approximately 20 days are required to
establish a slime layer when the average water
temperature is 32 °C(Martin and Weller, 1973).
Approximately four months were required to develop
a slime layer in this investigation because the
temperature of the water was much lower.
The response of the filters during this initial
period was also profoundly influenced by the changes
which took place within the lagoon system. During
December, January, and the first half of February,
the lagoons were covered by ice and the ammonia
concentration increased appreciably. The ammonia
concentration continued to increase until the water
temperature increased to approximately 7°C. This
triggered an algal bloom which started February 22
and peaked on March 6. The bloom was terminated
by a rapid population increase by Daphnia. Large
numbers of these animals were present in the system
until the end of March. Grazing by Daphnia eventual-
ly lowered the suspended solids concentration in the
kgoon effluent to less than 10 mg/1.
The second time interval started March 23 and
extended through May 6. During this period the
water temperature increased to approximately 20°C
and the biological slime layer became fully developed
on the rock surfaces. The effect of this layer upon the
performance of the filters is vividly shown by the
suspended solids and the dissolved oxygen observa-
tions summarized in Tables 9 and 10. Throughout
Table 5. Summary of water quality measurements, effluent from the Eudora wastewater lagoon.
Month
February
Average
Range
March
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Water
Temp.
5.1
1.0
7.5
10.2
6.0
15.0
15.4
11.0
20.0
22.2
18.9
25.5
23.2
17.8
27.0
29.2
26.2
32.0
Dis-
solved
Oxygen
11.8
5.7
16.4
6.6
1.0
13.9
5.0
2.2
7.8
5.4
2.6
7.9
PH
7.6
7.3
8.2
7.8
7.4
8.5
8.0
7.2
8.6
8.6
8.3
9.3
8.6
8.3
8.8
8.8
8.5
9.1
TSS
73
46
123
66
9
156
47
25
64
54
34
89
52
42
67
57
42
69
VSS
58
45
77
47
8
106
33
13
54
41
29
58
40
27
52
44
32
57
Total
COD
132
76
188
139
88
208
99
64
140
102
68
139
96
82
114
99
77
136
Sol.
COD
41
20
68
56
20
92
65
52
88
52
32
68
45
31
56
49
36
65
Total
BOD5
28
15
39
16
7
30
20
9
30
16
8
25
13
9
18
14
9
17
Sol.
BOD5
7
5
10
5
3
8
5
2
8
3
2
6
3
2
5
4
2
6
Ammo-
nia
N
15.2
11.5
21.0
12.0
9.5
16.0
8.9
5.0
12.0
0.9
0.1
4.4
0.15
0.05
0.21
0.07
0.05
0.17
Phos.
P
8.1
7.0
9.4
6.5
4.7
9.5
6.1
3.4
10.3
2.7
2.0
3.5
2.3
1.9
2.5
1.6
1.3
1.9
Chlo-
rophyll
a + b
355a
176
514
278
142
548
176
131
228
144
86
194
aData collected fiom April 12 through 29.
-------
38
O'Brien
this period the concentration of ammonia nitrogen in
the system was large enough to support a significant
amount of algal regrowth in the ponds behind the
filters. Regrowth of algae has continued to occur in
these ponds throughout May, June, and July, but the
magnitude decreased because of the drop in the
concentration of ammonia in the lagoon effluent.
The third time period started May 6 and will
continue through the remainder of the summer and
early fall. It has been characterized by a gradual
decrease in suspended solids in the effluent from the
submerged filters and by the onset of anaerobic
conditions within the filters. The anaerobic environ-
ment was first established in the downstream portions
of the filters and has slowly moved toward the
influent sampling tubes. The influent tube in both
filters was anaerobic throughout the bottom two-
thirds of the water column on July 29. The con-
centration of dissolved oxygen in the water moving
through the upstream face of the filters will continue
to fluctuate throughout the remainder of the summer
and the fall. The major variables which determine
how much of the filter volume is aerobic are water
temperature and the velocity of water entering the
filter.
A bright green scum layer consisting primarily
of Chlorella and numerous species of protozoa and
rotifers developed upon the surface of the ponds
behind the filters in late April and continued to occur
intermittently throughout May, June, and July. The
conditions which lead to the development of this
layer were apparently the release of ammonia by the
anaerobic decomposition of algae in the filters and
the relatively thin layer of oxygenated water near the
pond surface. The effect of this scum on the effluent
quality is not directly reflected in the parameters
summarized in Tables 7 and 8 because the baffles on
the effluent structure were withdrawing water from
the ponds at approximately the mid-depth.
The original objective in providing ponds be-
hind the filters was to increase the concentration of
dissolved oxygen and to lower the concentration of
ammonia in the final effluent. However, as indicated
in Tables 7 and 8, the ponds have not been effective
for oxygen transfer and have produced a significant
Table 6. Summary of water quality measurements, influent to the experimental lagoon.
Month
February
Average
Range
March
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Water
Temp.
4.9
1.0
7.5
10.0
5.0
17.0
14.4
10.4
19.0
21.5
18.1
25.0
23.8
19.8
26.5
28.2
26.0
30.6
Dis-
solved
Oxygen
5.3
1.0
8.2
3.3
0.5
6.3
3.5
1.8
5.1
0.6
0.2
1.6
pH
7.6
7.3
8.1
7.7
7.4
8.1
7.9
7.3
8.5
8.5
8.1
9.2
8.5
8.3
8.8
8.6
8.4
8.8
TSS
67
45
117
63
11
157
42
20
75
48
30
72
44
38
58
48
33
64
VSS
56
38
87
45
9
109
31
13
51
39
23
55
34
23
44
36
24
53
Total
COD
147
112
172
139
76
220
113
76
160
100
72
141
84
69
96
104
85
144
Sol.
COD
55
28
76
57
32
84
64
52
84
49
36
76
43
27
51
50
38
69
Total
BOD5
27
15
37
17
7
34
19
8
31
19
9
32
12
9
17
11
7
15
Sol.
BOD5
6
5
8
5
3
8
5
1
8
3
2
5
3
1
6
4
2
6
Ammo-
nia
N
15.5
12.5
20.0
11.3
18.0
9.0
8.2
4.7
13.0
0.95
0.05
3.50
0.18
0.05
0.80
0.20
0.05
0.30
Phos.
P
7.9
7.3
8.4
6.4
3.1
8.6
5.8
3.4
7.6
2.8
2.2
3.3
2.3
2.0
2.6
1.7
1.3
1.9
Chlo-
rophyll
a + b
314a
175
382
246
114
443
162
130
200
123
31
168
Data collected from April 12 through 29.
-------
Polishing Lagoon Effluents with Submerged Rock Filters 39
deterioration in the net removal of suspended solids
by providing an environment conducive to algal
multiplication prior to final discharge of the effluent.
A more effective configuration for the system would
be to abut the filter to the lagoon berm. The effluent
would be removed through a submerged conduit and
aerated prior to final discharge.
A filter system based on this concept has been
designed by Lane-Riddle Engineers, Inc. of Higgins-
ville, Missouri, to upgrade an existing lagoon system
located at California, Missouri. This installation con-
sists of three cells operated in series. The surface area
of each cell at the 1.52 m (5 ft) water depth are:
Primary 7.49 ha (18.5 acres); secondary 2.27 ha (5.6
acres), and tertiary 0.77 ha (1.9 acres). The design
population is 3600 based on an average flow of
378.51/capita/day (100 BPcd). The rock filter is
placed along one side of the existing tertiary cell,
Figure 6. The rock used is a dolemictric limestone
obtained from a quarry near Jefferson City, Missouri.
The size gradation is summarized in Table 11.
The hydraulic loading on the filter is
405.51/day/m3 (3 gal/day/ft3). This is based upon
the inflow of 378.51/capita/day (100 gpcd) with no
adjustment for either evaporation or seepage. Only
the rock upstream from the effluent collection pipe is
considered part of the filter. The rock located
between the pipe and the existing berm is simply fill
material. The rock filter is placed upon a 15.2 cm (6
in) thick mat of crusher run base rock. The effluent
collection line consists of 48.77 m (160 ft) of double
perforated corrugated metal pipe connected to 54.86
m (180 ft) of single perforated corrugated metal pipe.
Both pipes are 16 gage metal and are 30.48 cm (12
in) in diameter. The pipes are connected to the
existing effluent structure through a series of cor-
rugated metal bends which control the water depth in
the tertiary cell at either 0.91 m (3 ft) or 1.52 m (5
ft). All metal parts are coated with asbestos bonded
asphalt. The interior and the exterior of the concrete
effluent structure is also coated with asphalt.
Oxygenation of the final effluent is provided by a
cascade aerator located at the end of the outfall pipe.
Construction of the filter at California, Missouri,
was done by city employees under the supervision of
B. J. Gilbert, Superintendent of Utilities. The con-
struction costs are summarized in Table 12. Obviously
Table 7. Summary of water quality measurements, effluent from the large rock filter.
Month
February
Average
Range
March
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Water
Temp.
5.1
2.0
7.5
10.2
6.8
17.0
14.8
10.5
18.9
21.6
18.1
25.0
24.3
18.8
26.8
28.4
26.1
31.1
Dis-
solved
Oxygen
7.0
1.5
12.5
0.5
0.0
2.5
0.1
0.0
0.3
0.4
0.0
1.2
pH
7.6
7.0
8.1
7.9
7.5
8.6
8.0
7.4
8.6
8.4
7.9
8.8
8.4
8.0
8.7
8.3
8.0
8.4
TSS
56
41
84
59
10
124
34
14
61
34
17
79
24
17
31
24
19
34
VSS
48
29
70
41
8
94
26
11
51
25
12
35
15
6
24
15
8
25
Total
COD
132
80
180
110
60
176
86
60
124
76
51
97
61
47
76
67
53
90
Sol.
COD
47
24
72
47
32
60
55
40
68
48
32
60
43
35
56
51
37
67
Total
BOD5
21
13
29
13
7
29
19
9
32
13
6
18
9
7
14
9
5
13
Sol.
BOD5
6
5
11
4
1
7
5
2
8
4
3
7
4
2
8
6
3
9
Ammo-
nia
N
14.7
12.5
19.5
7.9
2.3
18.0
5.0
2.0
8.5
1.26
0.90
2.30
1.13
0.60
2.60
1.49
0.69
3.00
Phos.
P
7.4
7.1
8.0
6.2
5.0
7.6
5.7
3.5
6.8
2.7
2.4
3.1
2.1
1.6
2.6
1.6
1.5
1.7
Chlo-
rophyll
a + b
206a
146
305
148
51
313
79
58
105
59
33
83
aData collected from April 12 through 29.
-------
40
O'Brien
the primary factor in the cost of a submerged rock fil-
ter is the filter rock. The design of the California,
Missouri, installation is prudently conservative in the
selection of both the rock size and the hydraulic load-
ing. When additional information is available to better
define the long term operating characteristics of sub-
merged filters, the use of smaller, more heavily loaded
units will undoubtedly occur.
A major question concerning rock filters is
solids buildup and either clogging or sloughing of
material by the system. This is a valid concern
because matter is not destroyed. The real question
then is, "How soon will the system fail?" Obviously
the answer cannot be based upon field experience
because filters have not been in use long enough to
provide this information. However, the problem may
be approached by considering a steady state mass
balance. The following assumptions are made:
1. The hydraulic loading rate on the filter is
1081.41/day/m3 (8 gal/day/ft3)
2. The average influent total suspended
solids are 60 mg/1 (80 percent VSS)
3. The average effluent total suspended
solids are 20 mg/1 (80 percent VSS)
4. The specific gravity of the fixed SS is 2.0
5. The specific gravity of the inert VSS is
1.0
6. Sixty percent of the influent VSS is non-
biodegradable
7. The final residue from the influent biode-
gradable VSS is 20 percent of the initial
mass and are inert VSS
Buildup Influent FSS (60-20) (0.20) = 8 mg/1
Influent Inert VSS (60-20) (0.80) (.60)
= 19.2 mg/1
Residual Biodegradable VSS (12.8 mg/1) (.2)
= 2.6 mg/1
AVolume/day
8 2.6 19.2
1
1
gal-
= (25.8) (8) (231 x ID"6) in3/ft3 = 0.04768 in3/ft3
or 17.40in3/ft3/yr.
Table 8. Summary of water quality measurements, effluent from the small rock filter.
Month
February
Average
Range
March
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Water
Temp.
5.1
2.0
7.5
9.9
6.8
14.0
14.8
10.5
19.0
21.7
18.5
25.0
24.5
18.9
26.5
28.6
26.2
31.2
Dis-
solved
Oxygen
6.9
1.8
13.2
0.6
0.0
2.0
0.1
0.0
0.3
0.2
0.0
0.5
PH
7.6
7.0
8.2
7.9
7.5
8.7
7.9
7.3
8.4
8.4
8.0
8.7
8.3
8.0
8.7
8.3
8.1
8.5
TSS
52
41
61
46
12
114
25
15
40
34
8
81
22
17
34
23
17
29
VSS
48
39
58
34
10
83
20
9
31
23
8
38
14
9
27
14
9
21
Total
COD
137
104
196
107
60
160
86
56
120
71
48
88
62
53
72
65
51
100
Sol.
COD
49
20
92
52
24
80
52
40
68
49
30
64
44
27
55
51
41
63
Total
BOD5
21
13
32
13
6
25
16
9
27
12
5
19
8
6
12
9
5
14
Sol.
BOD5
6
4
9
5
2
9
6
3
12
4
2
6
4
3
8
5
2
7
Ammo-
nia
N
15.0
12.0
20.0
9.4
5.0
14.5
6.5
4.5
10.0
1.47
0.80
2.80
1.49
0.65
2.70
1.90
0.96
3.40
Phos.
P
7.3
5.9
8.0
6.1
5.2
7.3
5.8
3.1
7.0
2.6
2.2
3.0
2.1
1.7
2.5
1.6
1.4
1.8
Chlo-
rophyll
a + b
140*
111
153
170
56
337
63
39
92
67
28
133
Data collected from April 12 through 29.
-------
Polishing Lagoon Effluents with Submerged Rock Filters
41
Table 9. Summary of water-quality measurements obtained from the sampling tubes located in the large rock
filter.
Month
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Maya
Average
Range
June
Average
Range
July
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
Water
Temp.
14.5
10.7
18.5
21.5
18.1
24.7
23.5
18.6
25.9
28.9
27.9
29.9
24.7
24.1
25.0
23.5
18.4
26.1
29.4
28.9
30.1
14.6
10.9
18.2
21.2
18.2
24.2
23.7
19.0
25.7
29.4
28.7
30.4
Dissolved
Oxygen
Tube
2.0
0.5
4.8
0.6
0.2
1.0
1.3
0.2
2.4
1.3
0.2
2.3
Tube
0.0
0.0
0.0
0.0
0.0
0.0
0.2
0.1
0.2
Tube
1.5
0.0
8.8
0.0
0.0
0.0
0.0
0.0
0.0
0.3
0.5
0.1
TSS
vss Total
v:>:> COD
Sol.
COD
Chlorophyll
a + b
No. 3 Influent Side of Filter
53
33
79
70
23
122
48
40
50
28
23
35
No. 2 Center
27
23
31
28
24
32
16
13
19
44
25
66
54 106
14 80
78 231
39 91
34 84
42 104
20
12
30
of Filter
16
10
21
20
14
23
11
8
15
54
46
61
48
42
53
243
166
417
217
84
432
154
124
187
75
71
81
106
89
147
No. 1 Effluent Side of Filter
24
7
39
29
19
49
29
23
35
11
9
14
20
4
35
21 73
13 50
35 98
17 67
10 55
24 84
6
2
9
53
44
68
53
46
68
136
78
175
85
53
146
79
58
89
Observations cover the period from May 20-31.
-------
42
O'Brien
Table 10. Summary of water quality measurements obtained from the sampling tubes located in the small rock
filter.
Month
Water
Temp.
Dissolved
Oxygen
TSS
u<::> COD COD
Chlorophyll
a + b
Tube No. 6 Influent Side of Filter
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
May3
Average
Range
June
Average
Range
July
Average
Range
April
Average
Range
May
Average
Range
June
Average
Range
July
Average
Range
14.9
10.6
18.8
21.6
18.1
25.8
23.6
18.9
26.0
29.6
27.9
30.9
25.5
25.2
25.7
24.0
19.0
26.3
29.8
29.0
30.3
14.5
10.8
18.7
22.4
18.8
25.6
24.2
19.9
26.4
29.5
29.2
29.9
1.8
0.4
3.2
0.8
0.1
1.8
3.4
1.8
5.2
2.0
0.1
4.1
Tube
0.0
0.0
0.0
0.0
0.0
0.0
0.2
0.1
0.3
Tube
0.1
0.0
0.3
0.0
0.0
0.0
0.0
0.0
0.0
0.1
0.0
0.2
60
35
90
122
31
242
45
37
49
34
31
40
49
26
78
102 298 46
25 89 39
208 642 56
37 95 46
29 81 41
43 112 50
28
24
36
278
150
389
208
101
386
168
132
180
No. 5 Center of Filter
26
19
32
24
20
28
12
8
14
No. 4 Effluent
16
3
28
27
15
40
20
17
23
12
12
13
17
15
21
18
15
24
9
6
12
Side of Filter
13
2
27
19 84 52
11 57 36
30 138 66
14 71 53
10 63 43
18 80 68
8
5
12
76
56
112
74
55
89
91
63
142
109
45
203
45
31
66
Observations cover the period from May 20-31.
-------
Polishing Lagoon Effluents with Submerged Rock Filters 43
Table 11. Size gradation of the rock used in the sub-
merged filter at California, Missouri.
% Passing Screen
by Weight
Screen Size
cm
85 -100
0- 15
0- 5
7.62 - 12.70
6.35- 7.62
below 6.35
Table 12. Construction cost of the submerged rock
filter installation at California, Missouri
(August 1974).
Filter Rock; 4787.90 tons @ $9.50/ton $45,485.05
4342.63 metric tons @
$10.47/metric ton
Base Rock; 514.30 tons @ $3.69/ton 1,897.77
466.47 metric tons @
$4.07/metric ton
Filter piping 3,675.84
Truck Loader and Operator; 106.5 hr @ 2,236.50
$21.00/hr
City Employees; Salary and Wages 1,327.15
Total $54,622.31
The porosity of both the large and small rock
used in this study was 0.44, so the void space is 760
cubic inches per cubic foot. On the basis of the
preceding example, it would take approximately 43
years to fill these voids with solids.
Obviously, the steady state assumption used
above is an over simplification. During the late fall,
winter, and early spring the rate of biological de-
composition will be extremely slow because of the
low water temperature. There will also be a period
during the spring when the TSS will be significantly
greater than 60 mg/1 due to the nutrients stored in
and released from the bottom sediment in the lagoon
system. The rate of decomposition during the sum-
mer months will be greater than the rate of solids
removal from the liquid flowing through the filter
during this period. The rate of solids accumulation
during part of each year could easily be several times
that computed for the steady state system. The
effective life of a rock filter will, therefore, be shorter
than the value computed in the example. However,
because of the extremely low organic loading on
submerged rock filters, and the slow rate of solids
accumulation within these filters, the effective life
should exceed the 20 to 30 design year life used for
alternative treatment techniques.
The void space available in both of the rock
filters constructed for this investigation was approxi-
mately the same. However, the size of the voids is
also important because the many small volume voids
located between small rocks can be plugged by the
layers of biological slime formed on the rocks. This
type of failure is expected to eventually occur in the
small rock filter used in this study. On the basis of
the information presently available, a filter having
voids which are large enough to avoid plugging can be
constructed from rock having a minimum size grada-
tion approximately equal to the large rock filter used
in this investigation and a maximum size gradation
approximately equal to the filter installed at Califor-
nia, Missouri. As the rock size gradation increases the
maximum allowable hydraulic loading will decrease.
However, additional research will be required before a
precise relationship between rock size, flow rate, and
suspended solids capture efficiency is available.
As shown in Tables 9 and 10, during the initial
period of operation most of the reduction in sus-
pended solids occurs in the first 2.74 m (9 ft) of
horizontal flow through the rock. The solids capture
efficiency of this portion of the filter will decrease
with time because the volume of void space will
become smaller as inert material builds up and the
velocity of flow through this portion of the filter
increases. The net effect is analogous to the sedi-
mentation phenomenon observed in slightly inclined
tube settlers. In these units the settling zone moves
downstream along the axis of the tube as the time of
operation increases. Additional research is needed to
quantify this response in submerged rock filters.
A second area of concern is the production of
hydrogen sulfide by anaerobic decomposition of the
algae. In the absence of sulfate, algal decomposition
under anaerobic conditions consists of the production
of volatile acids and their subsequent reduction to
methane. However, if sulfite is present no methane
fermentation occurs (Lawrence et al., 1966). A
reasonably accurate prediction of the rate of sulfide
production can be made by considering the COD
change in the system (Force and McCarty, 1969). The
reaction is:
• S=+4H2O
In other words, 64 g of organic matter, on a COD
basis, will reduce one mole of sulfate and produce 32
g of sulfide ion. The sulfide ion in turn establishes an
equilibrium with hydrogen ion to form HS" and/or
H2S depending upon the pH of the solution.
The data for June for the large rock filter can
be used to illustrate the magnitude of the problem.
The average total COD entering the experimental
lagoon was 84 mg/1 and the average total COD in the
sampling pipe on the effluent side of the filter was 67
mg/1. Therefore:
-------
44 O'Brien
Effluent collection
line 30.48 cm. dia.
double perforated
corrugated metal
pipe 48.77m. long.
Effluent collection
line 30.48 cm. dia.
single perforated
corrugated metal
pipe 54.86 m. long.
Effluent discharge
5.03 m
11.89 m
Section A-A
Effluent
structure
Existing
rock
rip-rap
Figure 6. Plan of submerged rock filter constructed at California, Missouri.
-------
Polishing Lagoon Effluents with Submerged Rock Filters 45
ACOD = 17 mg/1 and AS" = (17 mg/1) (fj)= 8.5 mg/1
The total alkalinity of the lagoon effluent at
Eudora ranges between 260-275 mg/1 as CaCO3. The
minimum pH observed within the filters is 7.9. The
primary ionization constant of hydrogen sulfide is 1.1
x 10"' at 25°C. Therefore, approximately 10.3
percent of the S= will exist as H2S (0.9 mg/1) and
89.7 percent will be HS- (7.9 mg/1). At the present
time the odor of H,S at Eudora is minimal. The
intensity of the H-S odor will be increased somewhat
by aerating the final effluent. However, in most
locations where lagoon systems are already in use this
will not be a significant problem.
A third area of concern is the increase in
ammonia nitrogen in effluent from the rock filter. In
the pilot scale units this increase ranged from 2 to 3
mg/1 as nitrogen. The increase observed in the field
scale filters has ranged from 1 to 2 mg/1. It is
important to remember, however, that the total
ammonia concentration in the effluent is between 1
to 4 mg/1 as nitrogen. This is significantly less than
the 6 to 20 mg/1 of ammonia nitrogen present in the
effluent from conventional secondary treatment
systems (Earth and Mulbarger, 1966; Fruh, 1967). In
locations where the concentration of ammonia nitro-
gen in the receiving water is critical a very simple
adaptation of the submerged filter could be used to
nitrify the final effluent (McHamess and McCarty,
1973).
Conclusions
The following conclusions can be drawn from
the three phases of investigation that have been
carried out on the submerged rock filter:
1. During the first six months of operation the
field scale installation has responded in the same way
the pilot scale system did during the summer of 1973.
Both units went through an initial phase during which
the biological slime layer was becoming established
on the rock surfaces. During this period the capture
of suspended solids was relatively poor. After the
biological slime layer was established on the rocks the
removal of suspended solids increased dramatically.
2. The biological slime layer will function in an
anaerobic environment during part of each year. This
will require providing aeration facilities for the filter
effluent. This unit need not be elaborate and in many
instances a sample cascade aerator will be sufficient.
3. If sulfate is present in the carriage water,
hydrogen sulfide will be produced. If the total
alkalinity in the lagoon effluent is greater than 260
mg/1 as CaC03 the pH of the final effluent wfll be
high enough
minimum.
to reduce the odor problem to a
4. The rate of solids accumulation in the filters
will be very slow. As long as the size of the void space
between the rocks is large enough the prevent
plugging the effective life of the filter should be
greater than 20 to 30 years.
5. Rock sizes greater than 2.54 cm and less
than 12.70 cm will make satisfactory filters. Most of
the rock used in any one filter should be within a
range of 5 cm in diameter to insure a maximum
amount of void volume. As the rock size increases the
maximum allowable hydraulic loading will decrease.
More investigation is needed to fully define the
relationship between rock size and hydraulic loading.
6. Enough information is now available to
establish tentative design guidelines for submerged
rock filters. These guidelines can be further refined as
additional data becomes available.
7. Submerged rock filters are not going to be a
panacea for all lagoon installations. However, the
results obtained to date indicate these units will be
applicable for upgrading the lagoon systems already
in operation in many small municipalities.
Acknowledgmen ts
The major portion of this investigation was
carried out under contract 68-0280 between the
Environmental Protection Agency and the University
of Kansas Center for Research. The cooperation of
the City of Eudora, and most especially Mr. John N.
Pinnick, Superintendent of Utilities, is gratefully
acknowledged.
Laboratory assistants on the project were:
Christopher Yu, Hsiang Huang, Frank B. Nelson,
Richard A. Hirsekorn, Steven S. Innes, Lynn E.
Osborn, and Rodney J. Hofen
Bibliography
American Public Health Association. 1971. Standard meth-
ods for the examination of water and wastewater, 13th
Ed. A.P.H.A., New York, N.Y.
Earth, E. F., and M. Mulbarger. 1966. Removal of nitrogen
by municipal wastewater treatment plants. lout. Water
Pollution Control Federation, 38:1208.
Berry, A. E. 1961. Removal of algae by miciostiainers.
Journal American Water Works Association 53:1503.
Borchardt, I. A., and C. E. O'Melia. 1961. Sand filtration of
algae suspensions. Journal American Water Works
Association 35:1493.
-------
46
O'Brien
Dodd, J. C. 1973. Harvesting of algae with a paper precoated
belt-type filter. Dissertation Abstracts 34:2447-8.
Environmental Protection Agency. 1971. Methods for
chemical analysis of water and wastes. Analytical
Quality Control Laboratory, Cincinnati, Ohio.
Folkman, Y., and A. M. Wachs. 1973. Removal of algae from
stabilization pond effluents by lime treatment. Water
Research 7:419.
Force, E. G., and P. L. McCarty. 1969. The rate and extent
of algal decomposition in anaerobic waters. Proceedings
of the 24th Industrial Waste Conference, Purdue
University, 13.
Ftuh, E. G. 1967. The overall picture of eutrophication.
Jour. Water Pollution Control Federation, 39:1449.
Lawrence, A. W., P. L. McCarty, and F. J. A. Guerin. 1966.
The effects of sulfides on anaerobic treatment. Inter-
national Journal of Air and Water Pollution, 10:207.
Levin, G. V., et al. 1962. Harvesting of algae by froth
Flotation. Applied Microbiology 60:169.
Martin, D. M. 1970. Several methods of algae removal in
municipal oxidation ponds. M.S. Thesis, University of
Kansas.
Martin, J. L., and R. Weller. 1973. Removal of algae from
oxidation pond effluent by upflow rock filtration. M.S.
Thesis, University of Kansas.
McGarry, M. G. 1970. Algae flocculation with aluminum
sulfate and poly electrolytes. Journal Water Pollution
Control Federation 42:R 191.
McHamess, D. D., and P. L. McCarty. 1973. Field study of
nitrification with the submerged filter. EPA-R2-73-158
Environmental Pollution Technology Series, Environ-
mental Protection Agency.
O'Brien, W. J. et al. 1973. Two methods for algae removal
from oxidation pond effluents. Water and Sewage
Works 120:66.
Ort, J. E. 1972. Lubbock wraps it up. Water and Wastes
Engineering 9(9): 6 3.
Parker, D. S. et al. 1973. Algae removal improves pond
effluent. Water and Wastes Engineering 10(1):26.
Shindala, A., and J. W. Stewart. 1971. Chemical coagulation
of effluents from municipal waste stabilization ponds.
Water and Sewage Works 118:100.
Tenny, M. W. et al. 1969. Algal flocculation with synthetic
polyelectrolytes. Applied Microbiology 18:965.
U.S. Geological Survey. 1973. Methods for collection and
analysis of aquatic biological and microbial samples.
Book S, Chapter A4, Techniques of Water Resources
Investigations.
-------
STABILIZATION POND UPGRADING WITH
INTERMITTENT SAND FILTERS
E. J. Middlebrooks and G, R. Marshall
i
Introduction
Nature of the problem
Many rural communities are still fortunate to
be surrounded by large areas of open and relatively
inexpensive land. It was because of this land that
many of these communities adopted waste stabiliza-
tion lagoons as a means of wastewater treatment. This
treatment scheme requires large tracts of land, but
the important consideration was that it gave a
satisfactory effluent for minimum cost and main-
tenance. With the implementation of new water
quality standards, a better quality effluent is neces-
sary. If small cities and towns are to economically
produce a higher quality effluent, some form of
treatment must be utilized that will continue to take
advantage of the large areas of relatively inexpensive
land surrounding these communities. One method of
treatment that capitalizes on the availability of large
land areas is intermittent sand filtration.
Objectives
The objective of this study was to evaluate the
performance of laboratory and pilot field scale
intermittent sand filters as a polishing process that
would upgrade existing wastewater treatment
facilities. Particular attention was directed toward
ascertaining the effectiveness of the intermittent sand
filter as a means of removing the highly variable
quantities of algae present in stabilization ponds
during the warmer months of the year. These results
were used to develop preliminary design criteria for
intermittent sand filters that would consistently
produce an effluent of a quality that would meet
stringent water quality standards. Details of this
study were reported by Marshall and Middlebrooks
(1974).
'E. I. Middlebrooks is Dean, College of Engineering,
and G. R. Marshall is Research Assistant, Division of
Environmental Engineering, College of Engineering, Utah
State University, Logan, Utah.
History of intermittent sand filters
Intermittent sand filtration of sewage began in
this country in 1889 in Massachusetts, and for many
years was centered in the New England area. Approxi-
mately 450 intermittent filter plants were in opera-
tion in this country during 1945. But later reports
showed a decrease to 398 in use by 1957. Of those
still in use by 1957, 94 percent were serving
communities with populations under 10,000 (ASCE
and FSIWA, 1959).
Successful research efforts at the Lawrence
Experiment Station, Lawrence, Massachusetts, re-
sulted in an increase in the use of intermittent sand
filters until land costs forced many communities to
seek other methods of treating wastewaters. Large
numbers of small residential centers such as isolated
tourist courts, motels, trailer parks, drive-in theaters,
consolidated schools, and housing developments be-
gan to spring up all over Florida following World War
II. It was soon realized that an economic method of
sewage treatment would be necessary for these small
communities, and the study of intermittent sand
filtration was undertaken at the University of Florida
at Gainesville (Calaway et al., 1952; Furman et al.,
1949; and Grantham et al., 1949). Much of the
modern day knowledge on intermittent sand filters
has come out of the studies carried out at Gainesville.
Methods and Procedures
Experimental equipment
The study consisted of both laboratory (Phase
I) and field scale (Phase II) experiments.
Laboratory study
Nine laboratory scale filter columns were
erected as shown in Figure 1. Each individual filter
column was constructed of 6-inch diameter (15 cm)
plexiglass cylinders 6 feet (1.85 m) in length. A
flanged coupling was provided in the middle of each
column to facilitate the filter cleaning operation.
47
-------
I'-,
Middlebrooks and Marshall
Figure 1. Nine laboratory scale intermittent sand filters shown during daily
loading under laboratory conditions.
The filter underdrain material for each labora-
tory filter consisted of 3-inch layers of 1/4, 3/4, and
\Vi inch maximum diameter rock supported on
stainless steel mesh. A depth of 28 inches (71 cm) of
filter sand was then placed upon the quarter inch
diameter rock (6 mm). Sands with effective sizes of
0.17, 0.35, and 0.72 mm and uniformity coefficients
of 5.8, 3.8, and 2.6, respectively, were employed.
The 0.17 mm (.0067 inch) effective size sand
was the basic sand from which the other two sizes
were produced. The sand was a washed bank run sand
that was primarily used as fine aggregate in concrete.
The 0.35 mm (.0137 inch) sand was produced by
sieving the 0.17 mm (.0067 inch) sand through a U.S.
series number 50 sieve, the 0.35 mm (.0137 inch)
sand being the portion remaining on the sieve. The
0.72 mm (.0283 inch) sand was produced through the
use of the U.S. series number 30 sieve.
Logan City, Utah, wastewater stabilization
pond effluent was applied once daily to each of the
laboratory filters. In order to control the suspended
solids concentration in the lagoon effluent applied to
the filters, the wastewater effluent was diluted, if
necessary, with aerated tap water. Dilution factors
were determined on a day to day basis by carrying
out a daily suspended solids analysis on the filter
influent. Also, prior to dosing, the water temperature
was recorded in addition to any other observations
noted that day with respect to general filter operation
or lagoon performance.
Hydraulic loading rates of 100,000 gpad
(153.18 m3/hectare-day), 200,000 gpad (306.36
m3 /hectare-day), and 300,000 gpad (459.54
m3/hectare-day) were applied throughout the experi-
ment. Three loading periods of approximately 6
weeks in duration were employed. A loading period
constituted a period of operation during which the
applied algae concentration was held constant. Plug-
ging is defined as the point in time when all of the
specified quantity of wastewater placed on a filter
does not pass through the filter in a 24-hour period.
Plugging did not occur during any of the three
loading .periods in the laboratory. At the end of the
Loading Periods I and II, the filters were dismantled,
the top 10 cm (4 inches) of sand removed from each
and replaced with new sand of the same specifica-
tions, and the filters were returned to service the
same day. At the end of Loading Period III, the top
of the sand bed was not removed and daily operation
was continued to determine an estimate of the time
of operation possible before plugging occurs.
Suspended solids concentrations of 15 mg/1
(Loading Period II), 30 mg/1 (Loading Period I), and
45 mg/1 (Loading Period III) were maintained
through each of the loading periods. During the first
two loading periods, the wastewater used for filter
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 49
Figure 2. Nine prototype intermittent sand filters located at the point of dis-
charge for the Logan City wastewater stabilization ponds which
were used for study under actual field conditions.
loading was obtained directly from the Logan City
Wastewater Stabilization Ponds. This water was ob-
tained once weekly and stored under refrigeration for
use throughout the remainder of the week. During
the final loading period, the influent to the filters was
obtained from model stabilization ponds operated in
the laboratory. These ponds were enriched with
inorganic nutrients and were illuminated on a fixed
cycle of 16 hours of light and 8 hours of darkness. In
addition, when water was removed each day for filter
loading, the sample was replaced with tap water and
once weekly the sample was replaced with water
obtained from the Logan City wastewater stabiliza-
tion ponds.
Field study
Nine prototype field filters were erected at the
discharge point of the Logan City wastewater stabili-
zation ponds and are shown in Figure 2. These units
were 4 feet square (1.2 m x 1.2 m) and 6 feet (1.8 m)
in height and were constructed of exterior plywood
lined with fiberglass and resin. Underdrain construc-
tion was the same as the laboratory filters with the
exception being that each of the three layers of gravel
were 4 inches (10 cm) in depth.
Six filters each were filled with sands of
effective sizes of 0.17 and 0.72 mm (.0067 and .0283
inch) to depths of 30 inches (76 cm). The remaining
three units were initially filled with 1/4 inch (6 mm)
maximum diameter rock to a depth of 60 inches (152
cm). Later in the study the 1/4 inch rock was
replaced with sand of 0.17 mm effective size provid-
ing six filters with the basic sand.
Lagoon effluent was applied to the filters with
three calibrated pumps operated for a specified
period of time. During the fourth week of operation,
spreading units were installed to assure better
distribution of the raw water on the filter bed. A
typical spreading unit is shown in Figure 3.
During the first season of operation, the field
filters were also loaded once daily at rates of 100,000
gpad (153.18 m3/hectare-day), 200,000 gpad (306.36
m3/hectare-day), and 300,000 gpad (459.54 m3/hec-
tare-day). The hydraulic loading rates applied in the
second season are summarized in Table 1. The filter
containing 0.17 mm effective size sand loaded at
900,000 gpad (1,378.62 m3/hectare-day) was
operated at this rate for only 28 days because of the
lack of adequate freeboard to compensate for changes
in percolation rate due to increased head loss.
A daily sample of filter influent was taken for
suspended solids and pH analyses. All other influent
parameters were measured on a weekly basis with the
exception being the bacteriological samples which
were taken immediately following the daily dosing
with stabilization pond effluent. No attempt was
-------
50 Middlebrooks and Marshall
made to maintain a specified suspended solids con-
tent in the field experiments.
Sampling
Laboratory filter effluent samples were col-
lected once weekly and composited from 2 days of
operation. Filter influent samples were collected for
analysis on the days corresponding to the effluent
composite sample.
Figure 3. Typical troughs used on the field prototype
filters to protect the sand bed and to evenly
distribute the applied wastewater over the
filter bed.
Raw or influent water samples for bacterial
analysis were collected just prior to adding the pond
effluent to the filters and analyzed for total bacteria
and total coliform bacteria. The following day,
effluent samples were then taken and analyzed for
total bacteria and total coliform bacteria.
Effluent samples from the field filters were
collected once a week and the samples were taken
immediately following the application of the pond
effluent. A filter influent sample was taken daily.
Analyses
Suspended solids, pH, and temperature mea-
surements were performed on filter influent samples
on a daily basis for both the laboratory and the
prototype field filters. Filter influent and effluent
samples were analyzed once weekly for biochemical
oxygen demand (BOD), ammonia, nitrite, nitrate,
orthophosphate, total unfiltered phosphorus, sus-
pended solids, and pH. In addition, flask bioassays
were performed on the laboratory filter effluent to
determine if viable algae cells were in the effluents.
Approximately 200 ml of each filter effluent were
placed in a 500 ml Erlenmeyer flask and exposed to
the lighting pattern described for the laboratory
ponds. Growth was measured three to four times
weekly in each flask by determining the optical
density of the suspension.
Suspended and volatile suspended solids, reac-
tive orthophosphate, and reactive nitrite and nitrate
were measured by methods outlined in the Practical
Handbook of Seawater Analysis (Strickland and
Parsons, 1968). Total phosphorus and biochemical
oxygen demand analyses were performed in accor-
dance with Standard Methods (1971). Ammonia
concentration was determined by methods described
in Limnology and Oceanography (Solorzano, 1969).
Table 1. Physical characteristics of the filters and the hydraulic loading rates applied to the field filters.
Filter
Unit
Code
A4
A5
A6
A7
A8
A9a
C4
C5
C6
Effective Size
mm
0.17
0.17
0.17
0.17
0.17
0.17
0.72
0.72
0.72
of Sand
inches
0.0067
0.0067
0.0067
0.0067
0.0067
0.0067
0.0283
0.0283
0.0283
Filter
Depth
in
30
30
30
30
(0
JO
K)
!()
30
Hydraulic
gpad
400,000
500,000
600,000
700,000
800,000
900,000a
400,000
500,000
600,000
Loading Rate
m /hectare-day
612.72
765.90
919.08
1,072.26
1,225.44
1,378.62
612.72
765.90
919.08
aLoaded at this rate for 28 days only.
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 51
Total plate counts were made in accordance with
Standard Methods (1971) with the exception being
that all plates were incubated at 20 °C for 7 days
(Calaway et al., 1952). Total coliforms were deter-
mined by the procedures described in Standard
Methods (1971).
Results and Discussion
Algae genera
Laboratory filters
Water applied to the laboratory filters were
effluent from domestic wastewater stabilization
ponds and many different species of algae were
present. Chlamydomonas sp. was predominant in
both the Logan City and the laboratory stabilization
ponds. In most cases, the predominant groups of
organisms in the filter effluent were "fusiform
diatoms." They appeared at one time or another in all
effluent samples studied and were observed quite
regularly in the applied water.
There were cases where Chlamydomonas sp.,
Scenedesmus sp., and diatoms were observed separa-
tely and in various combinations in the effluents.
There were a few effluent samples in which algae
ZYX5 M^8 usually occurredin *« °17
mm (0067 inch) effective size sand subjected to the
lowest loading rate. When the lagoon effluents were
applied to the filters, the alpe, Chlamydomonas sp.,
were usually found in a "clumped" or palmelloid
state and in the effluent were observed to be single,
motile cells in nearly every case. This palemelloid
state may have contributed significantly to the
removal efficiencies obtained with the filters.
Field filters
Table 2 summarizes the results of the micro-
scopic analyses for the field filters. As reported for
the laboratory filters, Chlamydomonas sp. were again
predominant in the filter influent during the second
year of the field study. A variety of genera was
present in the lagoon effluent, but Chlamydomonas
sp. represented a minimum of 70 percent of the algal
population throughout the study.
Oxidation of nitrogen
Laboratory filters
Ammonia concentrations in the influents and
effluents were not measured until Loading Period III.
As the applied, effluent and removal values show
(Table 3), ammonia was present in large quantities
and was readily oxidized. This is in agreement with
earlier results reported at the University of Florida
where settled primary sewage was applied to inter-
mittent sand filters (Furman et al., 1949; and
Grantham et al., 1949).
Table 4 shows the relationship between
hydraulic loading rate, sand size, and the effluent
nitrate concentration for the three algal concentra-
tions applied (Loading Periods I, II, III). During
Loading Period III, the ammonia concentration,
Table 3, was found to be high in the artificially
produced wastewater stabilization pond effluent
when compared with concentrations that would be
expected to exist in a tertiary treated wastewater
stabilization pond effluent. Thus, the large increase in
nitrification observed during Period HI, when com-
pared with that of Periods I and II, was probably
Table 2. Algae genera population estimates for the influent and effluent samples from the field filters.
Sample
Date
26 July
2 Aug.
9 Aug.
15 Aug.
22 Aug.
28 Aug.
7 Sept.
13 Sept.
19 Sept.
27 Sept.
Genera
Influent
Sample
Chlamydomonas
Anabaena
0%
0%
0%
a
a
5%
10%
15%
20%
10%
Vegetative
25%
25%
25%
20%
5%
5%
10%
10%
5%
a
Palmelloid Daphnia
70%
70%
70%
70%
85%
80%
75%
75%
70%
80%
a
a
a
a
a
a
a
a
a
a
Diatom
5%
5%
5%
5%
5%
5%
5%
a
5%
10%
Euglena
a
a
a
5%
5%
5%
a
a
0%
0%
AS
Anabaena
0%
0%
0%
0%
0%
0%
a
5%
10%
0%
& C5 Effluent Samples
Chlamy.
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
80% (dead)
75% (dead)
80% (dead)
Debris Diatom
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
15%
15%
15%
15%
15%
15%
15%
15%
15%
20%
Occasional.
-------
52
Middlebrooks and Marshall
Table 3. Mean applied and effluent ammonia nitrogen concentrations obtained during Loading Period III in the
laboratory study.
Applied
NH4-N
(mg/1)
2.13
Effluent NH4-N Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
.006 .004 .006
0.35 mm
Hydraulic
Loading Rates,
gpadx la3
100 200 300
.006 .014 .017
0.72 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
.043 .146 .217
Table 4. Mean applied and effluent nitrate nitrogen concentrations obtained in the laboratory study.
Loading
Period
I
II
III
Applied
NCyN
(mg7l)
0.034
0.110
0.165
Effluent NO3-N Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10~3
100 200 300
1.45 1.25 1.20
0.96 0.91 0.91
4.04 3.57 3.89
0.35 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
0.99 1.12 1.63
0.84 0.81 0.74
3.82 3.44 3.03
0.72 mm
Hydraulic
Loading Rates,
gpad x 10~3
100 200 300
1.06 1.02 1.09
0.82 0.71 0.76
3.97 3.17 2.81
caused by the greater amounts of ammonia nitrogen
present in the artificially enriched wastewater ef-
fluent produced in the laboratory ponds, and was
probably not related to the increased applied algae
concentrations during Loading Period III.
Filters constructed of sands with smaller effec-
tive sizes more readily oxidized ammonia to nitrate
(Table 4). This result agrees with the findings of
Grantham et al. (1949), Furman et al. (1949), and
Pincince and McKee (1968).
Table 3 shows the changes in ammonia-nitrogen
concentrations at the three hydraulic loading rates
and filter sand sizes. The 0.72 mm (.0283 inch)
effective size sand filter showed a slight decrease in
ammonia-nitrogen reduction as the hydraulic loading
rate increased. This decrease was probably caused by
increased submergence, decreased aeration, and a
reduction in the contact time within the filter bed.
Field experimental results shown in Tables 5
and 6 were in agreement with the results observed in
the laboratory filters. The 0.17 mm (.0067 inch)
effective size sand was somewhat more efficient in
the oxidation of ammonia-nitrogen than the 0.72 mm
(.0283 inch) sand. Ammonia-nitrogen oxidation was
not continued in the second year of the field study;
however, as the hydraulic loading is increased, a
corresponding decrease in oxidation would be ex-
pected. The rock filtering media oxidized little of the
ammonia-nitrogen to nitrate. This is probably due to
the short time required for the liquid to pass through
the media.
BOD removal
Laboratory filters
As shown in Table 7, the concentration of
BOD5 in the lagoon effluent applied to the labora-
tory filters was close to the existing Utah standard of
5 mg/1 even before filtration during Loading Periods I
and II. This was caused by two factors: The necessity
to dilute the effluent to obtain the desired suspended
solids concentration applied to the filters, and the
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 53
Table 5. Mean applied and effluent ammonia nitro-
gen concentrations obtained in the field
study during the first year.
Applied
NH4-N
(mg/1)
1.09
Mean Effluent
NH4-N Concentrations, mg/1
.17 mm
0.013
.72mm
0.426
6 mm max.
dia. rock
1.10
Table 6. Mean applied and effluent nitrate nitro-
gen concentrations obtained in the field
study during the first year.
Applied
NO,-N
(mg/1)
0.078
Mean Effluent
NO3-N Concentrations, mg/1
.17 mm
0.996
.72mm
1.11
6 mm max.
dia. rock
0.479
Table 7. Mean applied and effluent BOD5 concentrations obtained in the laboratory study.
Loading
Period
I
II
III
Applied
BOD5
(mg/1)
6.71
6.34
36.5
Effluent BOD5 Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10~3
100 200 300
1.15 1.55 2.31
1.17 1.26 1.96
5.81 5.64 7.14
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
2.51 2.61 2.97
2.44 2.08 2.41
11.21 10.83 11.53
0.72 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
2.89 3.09 3.01
2.33 2.50 1.93
12.26 12.72 13.25
high degree of BOD5 removal produced by the
5-stage Logan lagoon system.
Results of the laboratory study were in good
agreement with results obtained by Grantham et al.
(1949). Examination of Table 8 shows that the
loading rates used had little effect on BOD5 removal.
However, the data show a trend toward an increase in
the concentration of BOD5 in the effluent as the
loading rate increased. Higher loadings would probab-
ly show an even greater increase in effluent BOD5
concentrations for all sand sizes. With respect to sand
size, the effect of loading rate does slightly decrease
the filter's ability to remove the applied BODS which
agrees with the findings of Grantham et al. (1949).
Field filters
At the same hydraulic loading rates as those
employed in the laboratory filters, BOD5 removals
obtained during the first year in the field units in
general agreed with the laboratory findings with the
exception being the lower removal efficiencies ob-
tained with the 0.72 mm (.0283 inch) sand used in
the field (Table 9). The differences in performance
summarized in Table 8 were probably caused by the
10-20°F greater operating temperature under labora-
tory conditions. In general, lower air temperatures
produce filter effluents with higher BOD5> This effect
was even more pronounced in larger sized sands
studied by Grantham et al. (1949). Coarser sands
allow better aeration which would allow the air
temperature to exert a much greater effect on the
biological activity.
The mean monthly influent and effluent BOD5
concentrations obtained during the second year of
field operation at various hydraulic loading rates for
the two effective size sands (0.17 and 0.72 mm) are
presented in Table 10. The BOD5 of the influent
remained essentially constant during the second year
of operation ranging from 10.0 to 24.9 mg/1 with an
average value of 13.7 mg/1 and a median value of 12.5
mg/1. There appears to be little variation in the
effluent BOD5 concentration with hydraulic loading
rate for the 0.72 mm effective size sand; whereas, the
0.17 mm effective size sand shows a definite increase
in effluent BOD5 concentration as the hydraulic
loading rate was increased. It is likely that the
effluent BOD5 concentration would also increase for
the 0.72 mm sand sizes if the loadings were increased
to 0.7 and 0.8 mgad.
The mean effluent BODe concentrations for the
0.17 mm effective size sand filters loaded at 700,000
and 800,000 gpad (1072.3 and 1225.4 m3/hec-
-------
54 Middlebrooks and Marshall
Table 8. The comparison of BOD, removal for the laboratory filters during Loading Period II and the field fil-
ters containing 0.72 mm (.0283 inch) size sand.
Hydraulic Loading (gpad)
100,000 (153.4 m3/hectare-day)
200,000 (306.4 m3/hectare-day)
300,000 (459.5 m3/hectare-day)
Percent BOD5
Removal
Under Laboratory
Conditions
(70°F Ave. Air)
63.2
59.6
69.6
Percent BOD5
Removal
Under Field
Conditions
(60°F Ave. Air)
24.3
17.8
29.6
tare-day) was twice as high as the values obtained at a
hydraulic loading rate of 600,000 gpad (Table 10). A
higher effluent concentration was expected, but
whether such a large increase would have occurred if
all of the filters had operated for an equal time period
is unknown. However, based upon the data collected
in this study it appears that BODs removal efficiency
reaches a limit in the vicinity of a hydraulic loading
rate of 600,000 gpad.
BOD5 reductions with the 0.17 mm effective
size sand filters ranged between 38.7 and 97.4
percent with the lower reductions occurring principal-
ly at the higher hydraulic loading rates (700,000 and
Table 9. Mean applied and effluent BODS concen-
trations obtained in the field study during
the first year of operation.
Applied
mg/1
6.18
Ave. Effluent BOD^ Concentrations, mg/1
0.17 mm
1.07
0.72 mm
4.70
6 mm max.
dia. rock
4.92
800,000 gpad). BOD5 reductions obtained with the
0.72 mm effective size sand appeared to be in-
dependent of the hydraulic loading rate and ranged
between 27.0 and 80.7 percent.
Mean BOD5 reductions for the second season
for the 0.17 mm sand ranged from 70.4 percent at a
hydraulic loading rate of 800,000 gpad to 88.4
percent for the 400,000 gpad rate. Mean BOD5
reductions for the 0.72 mm sand were essentially
constant for all hydraulic loading rates and ranged
from 59.9 to 63.2 percent.
Phosphorus removal
Phosphorus was initially removed by the inter-
mittent sand filters, but removal was greatly affected
by the length of time that the units had operated and
the hydraulic loading rate. Because little biological
growth occurs on or in the filter as the water passes
through, it is unlikely that any significant phosphorus
removal was obtained through growth needs. There-
fore, the most obvious explanation of the relatively
large phosphorus removals obtained at the beginning
of the experiments was ion exchange. The sands
contained some forms of carbonate which probably
Table 10. Mean influent and effluent BODs concentrations obtained with each sand size and hydraulic loading
rate during Phase II under field conditions.
Month
June
July
Aug.
Sept.
Mean
Monthly
Influent
BOD
Concen-
tration
(mg/1)
12.1
12.6
12.9
16.1
Mean Monthly Effluent BOD5 , mg/1
Effective Size, 0.17 mm
Hydraulic Loading Rates, gpad
400,000
ǥȣ
0.75 93.8
1.5 88.1
2.2 82.9
2.0 87.6
500,000
•* £.
1.2 90.1
0.87 93.1
3.1 76.0
1.7 89.4
600,000
•*£.
1.3 89.3
1.1 91.3
3.1 76.0
1.8 88.8
700,000
•* L.
3.5 72.2
4.2 67.4
3.4 78.9
800,000
"* £.
3.3 73.8
4.3 66.7
4.7 70.8
Effective Size, 0.72 mm
Hydraulic Loading Rates, gpad
400,000
-ȣ.
4.5 62.8
5.4 57.1
6.2 51.9
5.9 63.4
500,000
"•» &
3.6 70.2
5.7 54.8
5.8 55.0
5.1 68.3
600,000
-» M.
3.9 67.8
5.9 53.2
6.8 47.3
5.4 66.5
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 55
served as the exchange medium. Once saturated, there
would be no phosphorus removal of any con-
sequence. Phosphorus removals in the field units
followed the same pattern observed in the laboratory.
Algal removal
Algal concentrations in the influent were
estimated by the suspended solids technique which
measures a variety of organisms, inert suspended
matter, and a number of various algae species.
Effluent algal concentrations were also estimated as
volatile suspended solids to overcome the disad-
vantages of the silts and clays washed from the filters
during the early stages of the study.
Laboratory filters
Suspended and volatile suspended solids con-
centrations applied and in the effluents of the
laboratory filters are shown in Tables 11 and 12 for
the various hydraulic loading rates and sand sizes
employed. The suspended and volatile suspended
solids removals were independent of the hydraulic
loading rates employed. However, after the silt and
clay were removed, it appeared that a general trend
was developing which indicated an increase in ef-
fluent solids concentration as the hydraulic loading
was increased, particularly when greater concentra-
tions of suspended solids were applied.
Suspended solids removals were directly related
to the effective size of the sands at the higher solids
loading rates. At lower loadings the removals ob-
tained on the 0.72 mm (.0283 inch) sand were
approximately equal to the removals obtained with
the 0.35 mm (.0137 inch) filters.
Some algae passed through the entire depth of
the filter bed as verified by microscopic examination
of the effluents. Borchart and O'Melia (1961), Ives
(1961), and Folkman and Wachs (1970) have re-
ported similar results. Percent removal efficiencies
increased with the application of higher algal con-
centrations, but more algae passed the filter than at
the lowest applied concentration. Flask bioassay
results are presented later in an attempt to study the
ability of those algae present in the effluent to grow.
Field filters
Algal removals by the field filters during the
first year of operation are not shown because the silt
and clay that was washed from the filters made
interpretation of the results impossible. During the
second year of operation, algal concentrations were
Table 11. Mean applied and effluent suspended solids concentration obtained in the laboratory study.
Loading
Period
I
II
III
Applied
Suspended
Solids
mg/1
31.0
13.7
46.3
Effluent Suspended Solids Concentrations, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
5.53 7.93 11.2
3.96 4.80 6.05
1.86 1.93 5.33
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
10.6 10.9 12.8
9.39 8.19 6.50
9.47 11.9 13.7
0.72 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
13.6 11.9 11.0
11.0 8.15 7.28
16.6 15.9 16.5
Table 12. Mean applied and effluent volatile suspended solids concentrations obtained in the laboratory study.
Loading
Period
II
III
Applied
Volatile
Suspended
Solids
mg/1
9.16
41.3
Effluent Volatile Suspended Solids Concentration, mg/1
Effective Size of Filter Media
0.17 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
1.99 2.14 2.30
1.46 1.70 3.48
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
3.38 3.33 3.40
7.28 7.14 8.31
0.72 mm
Hydraulic
Loading Rates
gpadx 10'3
100 200 300
3.85 4.00 3.17
10.1 13.1 13.2
-------
56
Middlebrooks and Marshall
estimated by measuring fluorescence2 and by deter-
mining suspended and volatile suspended solids.
Linear regression analyses of the solids and
fluorescence measurements produced a linear rela-
tionship significant at the 1 percent level.
Influent and effluent algal concentrations ex-
pressed as suspended solids produced by the field
filters are summarized in Table 13. Volatile sus-
pended solids concentrations are shown in Table 14.
Data for the 0.17 mm effective size sand filter loaded
at 900,000 gpad are not presented because of the
relatively short period of operation. However, algal
removals were similar to those obtained with the
800,000 gpad loading rate.
Figure 4 shows the relationship between the
hydraulic loading rates and the suspended and volatile
suspended solids concentrations in the filter effluents
for the 0.17 and 0.72 mm effective size sands. Algal
removal apparently is independent of hydraulic load-
ing rate up to a loading of approximately 600,000
gpad.
Effluent suspended solids concentrations for
the months of May and June 1973 were much greater
than the concentrations in the effluents. This was
attributed to the washing of fines and clay from the
filter sand. Filter media were produced from pit run
sands containing large quantities of fines and clays
that were easily washed from the filters. Clean water
Table 13. Mean influent and filter effluent algal concentrations measured as suspended solids for each sand size
and hydraulic loading rate studied during Phase II under field conditions.
•&
1
May
June
July
Aug.
Sept.
Mean
Monthly
Influent
Algae
Cone, as
Suspended
Solids
(mg/1)
5.0
6.5
29.8
44.2
25.2
Mean Monthly Effluent Suspended Solids Concentrations and Percent Removals
Effective Size Sand, .17 mm
400,000
/i %
mg/1 Red.
25.1 -
15.7 -
14.2 52.3
23.2 47.5
8.7 65.5
Hydraulic Loading Rate, gpad
500,000
/i %
mg/1 Red.
56.0 -
38.9 -
23.9 19.8
18.8 57.5
13.6 46.0
600,000
m^1 Ited.
20.9 -
14.5 -
20.2 32.2
30.0 32.1
8.8 65.1
700,000
mg/1 Red
21.4 28.2
34.5 21.9
20.5 18.7
800,000
/i %
m^ Red.
15.4 48.3
39.1 18.6
16.5 34.5
Effective Size Sand, .72 mm
Hydraulic Loading Rate, gpad
400,000
m^ Red.
31.7 -
11.6 -
17.9 39.9
33.0 25.3
12.4 50.8
500,000
/i *
"^ Red.
7.5 -
9.4 -
14.4 51.7
22.4 49.3
12.4 50.8
600,000
m«/1 Red
15.9 -
12.5 -
16.9 43.3
26.9 39.1
11.4 54.8
Table 14. Mean influent and filter effluent algal concentrations measured as volatile suspended solids for each
sand size and hydraulic loading rate studied during Phase II under field conditions.
1
o
&
May
June
July
Aug.
Sept.
Mean
Monthly
Influent
Algae
Cone, as
Suspended
Solids
(mg/1)
2.2
3.6
23.6
34.3
22.3
Mean Monthly Effluent Volatile Suspended Solids Concentration and Percent Removals
Effective Size Sand, .17 mm
Hydraulic Loading Rate - gpad
400,000
•* Red.
2.2 -
1.6 55.6
4.5 80.9
5.1 85.1
2.7 87.9
500,000
"* R?d.
4.5 -
2.4 33.3
6.8 71.2
4.3 87.5
5.6 74.9
600,000
•*£
1.6 27.3
1.3 63.9
4.4 81.4
6.2 81.9
2.5 88.8
700,000
•*&
9.8 58.5
17.8 48.1
6.6 70.4
800,000
"* £.
5.6 76.3
13.7 60.1
8:4 62.3
Effective Size Sand, .72 mm
Hydraulic Loading Rate - gpad
400,000
"•"£
3.8 -
1.9 47.2
5.5 76.7
8.9 74.1
4.8 78.5
500,000
•*&.
1.5 31.8
1.7 52.8
4.9 79.2
12.1 64.7
2.1 90.6
600,000
m8fl M.
3.5 -
2.2 38.9
6.5 72.5
9.1 73.5
4.1 81.6
2G. K. Turner Associates, Palo Alto, California.
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 57
was not available to prewash the filters; therefore, it
was necessary to wash with effluent. Much more
material was washed from the 0.17 mm effective size
sand because much of the fines were removed when
preparing the 0.72 mm sand by screening.
At the 500,000 gpad hydraulic loading rate,
monthly mean volatile suspended removals were
essentially equal for the 0.17 and 0.72 mm effective
size sands. Efficiencies fluctuated considerably from
one sand to the other during the study period. But in
general the 0.17 mm effective size sand produced a
better quality effluent, particularly at the 600,000
gpad loading rate. Volatile suspended solids removal
efficiencies appeared to be improving with the age of
the filters, which is probably related to the washing
of debris from the units (Table 14).
Examination of the effluent suspended solids
concentrations at various hydraulic loading rates
shown in Figure 4 indicates that the 0.72 mm filters
were more efficient. However, the volatile suspended
31
30
29
28
27
26
25
24
23
18
co!7
916
o15
40 13
p!2
lit , |
o II
I'9°
co 8
to 7
6
5
4
3
2
I
0
/ N
'X—X AVERAGE
EFFLUENT S.S.
0.17mm FILTERS
0—0 AVERAGE
EFFLUENT S.S.
0.72mm FILTERS
X—X AVERAGE
EFFLUENT VSS. -
0.17mm FILTERS
0—0 AVERAGE
EFFLUENT VSS.
0.72mm FILTERS
l
i
II
m
c
9$
m
m
7o
60
r
5S
4?
(O
33
2
I
0.4 0.5 0.6 0.7 0.8
HYDRAULIC LOADING RATE, mgpad
Figure 4. The relationship between the suspended and volatile suspended solids concentrations and the
hydraulic loading rates for the field filters.
-------
58
Middlebrooks and Marshall
solids data show just the opposite. Again, this
discrepancy is explained by the washing of silt and
clay into the effluents.
Laboratory bioassay results indicated that as
greater concentrations of algae were applied to the
filters more viable cells passed through the 30 inches
of sand. As shown in Table 14, during August when
the algal concentration was at a maximum, more
algae as volatile suspended solids passed the filters.
Although removal efficiencies appeared to im-
prove with the age of the project, noticeable increases
in removal efficiencies as the filters approached
plugging did not occur. This is counter to the
laboratory results and cannot be readily explained
except by the variation normally occurring in solids
analyses.
Bacterial removal
Stream standards recently adopted by the State
of Utah include acceptable levels for both total and
fecal coliform organisms. The standards require that a
Class "C" water have an arithmetic monthly mean
value of total and fecal coliform that does not exceed
5,000 and 2,000 per 100 ml, respectively (Middle-
brooks etal., 1972).
Laboratory filters
Total coliform removals of better than 86
percent were obtained with all three sand sizes but
due to the high applied counts (610,000 colonies/100
ml) the process was not able to meet the earlier noted
standards in this particular application. Even at
removals above 95 percent, lesser numbers of applied
coliforms would have to be applied in order to meet
Class "C" discharge standards. Calaway et al. (1952)
presented similar results.
As the effective size of the sand was decreased,
coliform removals increased, which agrees with the
findings of Calaway et al. (1952). But, at the hydrau-
lic loading rates employed, total coliform removals
with the 0.72 mm (.0283 inch) sand were equal to
those obtained in the filters containing 0.35 mm
(.0137 inch) sand.
Total coliform removals were independent of
the hydraulic loading rates employed, but it is
doubted that this would apply at higher loadings.
Calaway et al. (1952) found that at hydraulic loading
rates approximately twice the rates used in this study
that bacteria penetrated the bed to much greater
depths. Therefore, more bacteria would be expected
to pass the filter at higher loading rates. However, at
the hydraulic loading rates of 100,000 (153.4
m3/hectare-day), 200,000 (306.4 mS/hectare-day),
and 300,000 (459.5 m3/hectare-day) gallons per acre
per day, the coliforms removal was independent of
loading.
Total plate counts for bacteria showed that the
total number of bacteria in the filter influent was
essentially unchanged by any of the three sand sizes
studied. Also, hydraulic loading rate did not affect
the numbers of bacteria present in the effluent.
Field filters
In an attempt to interpret the bacterial removal
results obtained with the laboratory filters, total
bacterial counts were performed on influent and
effluent samples collected from the 0.17 mm and
0.72 mm effective size sands with both loaded at
500,000 gpad (765.90 m3 /hectare-day). After the
0.17 mm filters plugged and were cleaned, total
bacterial counts were reduced by 99 percent three
days after operation was resumed. But after 18 days
of consecutive loading, the same filter effluent
contained higher concentrations of bacteria than
found in the influent. This increase in effluent
concentration with time of operation after cleaning is
probably attributable to two factors: (1) The
bacterial population in the filter dies off during the
drying period before removing the top few inches of
sand, and (2) when operation is resumed, the clean
sand serves as an efficient filter but as more and more
bacteria penetrate the bed and multiply, more are
washed into the effluent.
The intermittent sand filter is as much a
biological as a physical process and is capable of
producing large populations of bacteria within the
filter bed. Treatment provided by the intermittent
filter when used as a polishing device is accomplished
throughout the entire depth of the filter and not
limited to the top 12 inches of the bed as implied in
other studies.
Effluent algal bioassays
As mentioned earlier, microscopic examination
indicated that algae were passing through the filters.
In an attempt to quantify the degree of passage, flask
bioassays were employed to assess the number of
viable algae in the effluents.
Algal growth, measured by an increase in light
absorbancy, showed a much greater response in the
effluents obtained from the filters when receiving the
highest algal concentrations. Microscopic examination
also showed higher concentrations of algae in the
effluents when the highest concentration of algae was
applied.
-------
Stabilization Pond Upgrading with Intermittent Sand Filters
59
All of the flask assays exhibited a lag period of
approximately three days before any significant
growth occurred. This lag or acclimation period
required for the algae to respond to a new environ-
ment could be advantageous in that it would allow
the effluent to be transported considerable distances
before an effect could develop. This would allow
much of the algae that had passed the filter to settle
out or be scavenged before growth could develop. If
in the future it becomes necessary to meet more
stringent requirements, disinfection would eliminate
practically any surviving algal cells.
Microscopic examinations of the field filter
effluents yielded similar results, but flask bioassays
were not performed on the field filter effluents.
Filter conditions at plugging
Laboratory filters
Plugging did not occur during the three original
loading periods used in the laboratory study. To
obtain an estimate of the time required for plugging
to occur, dosing was continued after Loading Period
III without removing any sand from the beds and
using algal suspensions from the model stabilization
ponds. In order to estimate the plugging time under
the most severe conditions evaluated, it was decided
to continue loading at the Loading Period III con-
centrations.
A comparison of the effluent BOD5 values at
the time of plugging with those observed during
normal operation showed no noticeable differences.
Effluent suspended solids concentrations at the time
of plugging were almost equal and near zero. This
indicates that breakthrough does not occur in an
intermittent sand filter. This finding is in agreement
with the work of Ives (1961) which showed that as
the specific deposit increased, the filter coefficient
increased. Since the hydraulic head above the sand
was not increased to the point that the filter
coefficient was forced to decrease, the filters would
plug when the filter coefficient was at a maximum. If
it were practical to increase the head on intermittent
sand filters, breakthrough might occur as in a high
rate or pressurized filter.
Possibly the most important polishing
mechanisms in intermittent sand filtration is the
surface mat or "schmutzdecke" which is composed of
suspended matter trapped on the surface of the filter.
In this study the mat was composed primarily of
algae that had been deposited upon the sand surface.
Following Loading Periods I and II, the filters
did not seem to have a predominant surface skin of
deposited suspended matter. The top 2 inches (5 cm)
of sand seemed to be cemented together by the
trapped suspended matter. Below this, the sand
particles, although moist, were loose and apparently
unaffected by suspended matter. At no time was any
of the applied suspended matter detected at depths
below the top 2 - 3 inches (5 - 7.5 cm). Sand 2 - 3
inches (5 - 7.5 cm) below the surface mat examined
at the end of Loading Periods I and II did not appear
to be affected by the applied algal suspensions. Once
this sand had become dry, it was hard to tell it from
new, clean sand. As the individual filters began to
plug under the continued loadings following Loading
Period III, a more predominant skin was noted on the
sand surface. This skin was, in most cases, approxi-
mately one-sixteenth of an inch (1.6 mm) thick and
covered the entire filter. During Loading Period III,
the 0.17 mm (.0067 inch) and the 0.35 mm (.0137
inch) sands had surface mats that were moist,
somewhat porous, and flat or well conformed to the
sand surface. But the surface mat for the 0.72 mm
(.0283 inch) sand, although moist, was curled and
irregular. If a plugged filter is allowed to dry, the
surface mat will curl away from the top surface of the
sand. This indicates why raking or scraping has been
shown to extend the length of filter runs.
Field filters
At the higher hydraulic loading rates employed
in the field study, the surface mats for both the 0.17
and 0.72 mm sands followed essentially the same
pattern as that observed in the laboratory. The 0.17
mm field filters operated approximately the same
period of time before plugging as reported for the
laboratory filters (Table 15). At the loading rates
employed (400,000 to 600,000 gpad) with the 0.72
mm filters, plugging did not occur during the entire
study. Based upon the results of both the laboratory
and field studies, it appears that much higher
hydraulic loading rates can be employed with the
0.72 mm filters. Higher hydraulic loading rates may
result in more efficient solids removals with the 0.72
mm filters because of an increase in thickness of the
mat that would accumulate on the surface and serve
to trap more of the algae and debris. More detailed
economic studies of the operation of the filters needs
to be completed, but it appears that the hydraulic
loading rate for the 0.17 mm effective size sand filters
is limited to approximately 1 mgpad.
The 0.17 mm filters were cleaned by raking
only which accounts for the relatively short periods
of operation between the first and second plugging. If
a conventional cleaning by removing the top 2 - 3
inches of sand had been performed, the second period
of operation would have matched the initial period.
However, because raking is an inexpensive method of
extending the period between sand removals, it
-------
60
Middlebrooks and Marshall
Table 15. Operational history of the field filters during the second year.
Filter
A4
A5
A6
A7
A8
C4
C5
C6
Date
Began
Loading
14 May
14 May
14 May
9 July
9 July
14 May
14 May
14 May
Date
1st
Plug
10 Aug
10 Aug
7 Aug
10 Aug
10 Aug
27 Septa
27 Septa
27 Septa
Ave.
SSmg/1
Applied
20.75
20.75
18.18
42.12
42.12
25.10
25.10
25.10
Type
Cleaning
Rake
Rake
Rake
Rake
Rake
Date
Loading
Resumed
21 Aug
21 Aug
21 Aug
21 Aug
15 Aug
Date
2nd
Plug
27 Sept3
27 Sept3
12 Sept
27 Sept3
7 Sept
Ave.
SS mg/1
Applied
27.57
27.57
29.58
27.57
34.99
Date
Loading
Resumed
24 Sept
7 Sept
Plug
Type 3r(j
Cleaning Hug
Rake 27 Septa
Rake 27 Septa
Ave.
SSmg/1
Applied
24.57
23.82
Project ends.
should be considered part of the routine operating
procedure.
Time of operation
Laboratory filters
Figure 5 shows the effect of sand size and run
time before plugging occurs. It is again evident that
the finer sands produce the lowest effluent suspended
solids concentrations. But it is also quite apparent
that this improved effectiveness was attained at the
expense of a reduction in operation time before
plugging.
As the operating time increased, an increase in
the suspended solids removal efficiency was noted.
This is the same as noted by Ives (1961); i.e., as the
specific deposit increases, the filter coefficient in-
creases. Knowledge of this situation could prove to be
valuable when operating a number of filters. Regular
analysis of the effluent for suspended solids would
allow one to predict when plugging was likely to
occur.
Continued operation eventually caused plugging
in all filters. The results show that the 0.72 mm
(.0283 inch) filter operated 175 consecutive days
before plugging when loaded at a mean algal con-
centration of 51 mg/1, the 0.17 mm (.0067 inch) sand
operated 68 consecutive days at a mean algal con-
centration of 43 mg/1, and the 0.35 mm (.0137 inch)
sand operated 99 consecutive days at an applied algal
concentration of 45 mg/1.
s
Ul
32
A 0.1 7 mm
O 0.35mm
X 0.72mm
PLUGGED
PLUGGED
PLUGGED
_L
-I—I L
J 1 L
J I 1 L
15 22 29 36 43 50 51 64 71 78 65 92 99 106 113 120 127 (34 Wl (48 155 162 169 176 183 190
CONSECUTIVE DAYS
Figure 5. Observed times of operation under approximately 45 mg/I applied algae afforded by each sand size
under laboratory conditions and the resulting effect on effluent suspended solids concentration.
(Loading Period in plus continuation.)
-------
Stabilization Pond Upgrading with Intermittent Sand Filters
61
Table 16 shows in more detail the operational
results for all the filters during the continuation of
Loading Period III. Removing the top 4 inches (10
cm) of sand from the filters after plugging, replacing
it with new sand, and putting the unit back in
operation gives second performance periods generally
less than the original period. Longer operating periods
were expected with the lower hydraulic loading rates;
however, the 0.17 mm (.0067 inch) and 0.35 mm
(.0137 inch) effective size filters at the lowest loading
rate were the first to plug.
Figure 6 shows that the highest hydraulic
loading rate studied also allowed greater volumes of
applied water to pass the filter bed before plugging
occurred. As the figure shows, the result was the same
for all the sand sizes studied.
Field filters
As reported for the laboratory filters, the finer
sand produced a superior effluent in all categories
measured, and again this higher efficiency was at-
tained at the expense of a reduction in operation time
before plugging (Table 15).
The increase in suspended solids removal ef-
ficiency with increasing operating time was observed
for the field filters, but the effluent concentrations
appeared to reach a limit and did not continue to
drop until plugging occurred. The removal efficiency
increase with time of operation in the field filters
appeared to be more closely associated with the
washing of fines from the filters. However, there is no
reason not to expect similar performances between
the laboratory and field filters, and it may be that the
lack of a decrease in effluent solids concentration is
attributable to a continuous washing of fines from
the filters up to plugging. After more than one
summer of operation, it is likely that a pattern as
observed in the laboratory would evolve in the field.
Since the 0.72 mm field filters did not plug during
the summer of operation, it is possible that the
laboratory study results would have been duplicated
had the project continued, or had the suspended
solids concentrations in the influent been increased.
The 0.72 mm filters operated 137 consecutive
days without plugging when loaded at 0.4, 0.5, and
0.6 mgpad with a lagoon effluent containing an
average suspended solids concentration of 25 mg/1. It
was not surprising that these units did not plug,
because laboratory units with the same sand and a
hydraulic loading rate of 0.3 mgpad operated 175
days before plugging and were dosed with a lagoon
effluent containing an average suspended solids con-
centration of 51 mg/1.
The consecutive days of operation for the 0.17
mm filters appear to be directly related to the
hydraulic loading rates. Figure 7 shows that up to a
loading rate of 0.6 mgpad the filters operated
approximately 100 days before plugging when receiv-
ing a lagoon effluent containing a mean algal con-
centration of 20 mg/1. During these 100 days, the
filter influent algae concentration ranged from 4 to
51 mg/1. At loading rates of 0.7 and 0.8 mgpad, the
0.17 mm filters operated only 32 consecutive days
when receiving a lagoon effluent containing a mean
suspended solids concentration of 42 mg/1, and a
range of concentrations varying between 30 and 50
mg/1. Because of the large difference in the mean
applied suspended solids concentrations, it is impos-
sible to compare the performances at the two
Table 16. Results of the continuation of Loading Period III showing approximate period of operation by the
laboratory filters using two cleaning methods. Loading Period III began 11/1/72 at which time
all filters had the top 4 inches (10 cm) of sand removed and replaced with new sand.
Filter
SF11
SF12
SF13
SF21
SF22
SF23
SF31
SF32
SF33
Date
First
Plugging
4/14
4/27
4/25
12/26/72
12/27/72
3/5/73
12/18/72
1/28/73
1/17/73
Mean
Applied
SSto
Date
51.46
51.08
51.08
44.57
44.57
48.79
46.35
45.19
44.47
Type
Geaning
raking
scraping
scraping
raking
scraping
scraping
scraping
Date
Put
Back
in Use
4/20/73
1/10/73
1/10/73
3/8/73
1/10/73
1/30/73
1/30/73
Date
Second
Plugging
2/6/73
4/2/73
1/20/73
3/14/73
Mean
Applied
SS from
First
Plugging
51.76
53.59
63.56
Type
Geaning
scraping
raking
scraping
raking
Date
Put
Back
in Use
,2/8/73
1/30/73
3/21/73
Date
Third
Plugging
4/3/73
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62
Middlebrooks and Marshall
hydraulic loading rates, or to develop relationships
between consecutive days of operation and the
hydraulic loading rate.
The results are useful in estimating the number
of time during an algae growing season that the filters
must be raked and cleaned. During the early spring
and summer it is likely that the units will perform
effectively for the first 3 months, and removing the
top 2 to 4 inches of sand the units should perform a
minimum of one month even at very high algal
concentrations in the filter influent. It is possible that
the consecutive days of operation at the 0.7 and 0.8
mgpad hydraulic loading rates will match those at the
0.4 to 0.6 mgpad rates when receiving equal con-
centrations of influent algae. Length of operation and
the economics of maintenance will be answered in the
continuation of the project which will be conducted
on a prototype scale.
When the filters plugged, the surface mat and
approximately the top 2 inches of sand were raked
and broken up and then placed in service again.
Figure 7 shows that there was not a relationship
between hydraulic loading rate and consecutive days
of operation following the raking. The 0.17 mm
filters receiving 0.4, 0.5, and 0.7 mgpad of lagoon
effluent had loaded for 38 days and were still
operating after the first raking when the project was
terminated. The filters receiving 0.6 and 0.8 mgpad
plugged within 22 days after the raking. Mean
suspended solids concentrations in the lagoon ef-
fluent applied to all of the 0.17 mm filters following
raking were approximately equal, but the two filters
that plugged the second time did receive the highest
concentrations of algae, 29.6 mg/1 for the 0.6 mgpad
loading rate and 35.0 mg/1 for the 0.8 mgpad loading
rate.
Although direct comparisons of the lengths of
performance at the various hydraulic loading rates are
difficult, it is obvious that the length of runs for all of
the sands and hydraulic loading rates are of adequate
length to make intermittent sand filtration competi-
tive with all other processes available to upgrade
lagoon effluents to meet new water quality standards.
Figure 8 shows the volume of lagoon effluent
applied to the field filters during the 137 days of
operation. As reported for the laboratory filters, the
1000
(II) -0.72mm, lOO.OOOgpad
(12) -0.72mm,200,000gpad
(13) -0.72mm,300,000gpad
(21) -0.35mm,100,OOOgpad
(22) -0.35mm.200,OOOgpad
(23) -0.35mm,300,OOOgpod
(31) —0.17mm, 100,OOOgpod
(32) —O.I 7 mm,200, OOOgpad
(33) — 0.17 mm,300,OOOgpod
50 100 ISO 200
DAYS OPERATED UNTIL PLUGGING
2 SO
Figure 6. The relationship observed between the volume of water applied until plugging occurred under labora-
tory conditions. 1-66-6
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 63
105
CO
§ 99
o
O
o
O
o
a.
0
<
o
87
81
75
69
63
57
45
•
CO
o
o
33
27
81
15
X—X CONSECUTIVE DAYS OF OPERATION
- UNTIL FIRST PLUGGING
X---* CONSECUTIVE DAYS OF OPERATION
AFTER RAKING FLOWING FIRST PLUGGING
-^PROJECT TERMINATED BEFORE SECOND PLUGGING
0.4 0.5 0.6 0.7
HYDRAULIC LOADING RATE, mgpod
0.8
Figure 7. Consecutive days of operation until plugging occurred in the 0.17 mm effective size sand filters at
various hydraulic loading rates.
-------
64
Middlebrooks and Marshall
LU
UJ
13
0.
<
UJ
3
U.
O
2J
=3
115000
MOO 00
105000
100000
95000
90000
85000
SO 000
75000
70000
65000
60000
550001-
50000
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
TOTAL VOLUME OF SEWAGE /
EFFLUENT IN LITERS APPLIED TO /
EACH FILTER VS. TIME IN DAYS /
10 20 30 40 50 60 70 80 90 100 110 (20 130 140
TIME (DAYS)
Figure 8. Hie relationship observed between the volume of water applied until plugging occurred under field
conditions. Discontinuity in the lines represents the rest and cleaning period following plugging.
-------
Stabilization Pond Upgrading with Intermittent Sand Filters
65
greatest volume of water was treated in a given time
span by the filters receiving the highest hydraulic
loading rates even when plugging occurred and it was
necessary to rest the filter and rake the surface before
returning it to operation.
Overall evaluation of the process
Ability to meet present state standards
Intermittent sand filtration was evaluated to
assess its capability to produce an effluent that would
meet the Utah Class "C" stream standards shown in
Table 17 when imposed as discharge standards. In a
system such as the Logan City wastewater stabiliza-
tion ponds, the intermittent sand filter would pro-
duce an effluent meeting Class "C" discharge
standards 99 percent of the time. The 0.17 mm
(.0067 inch) effective size laboratory filters only
produced an effluent with a mean BOD5 greater than
5 mg/1 (maximum effluent BODs equal 8 mg/1) when
loaded at the highest algal concentration and with an
influent BODs concentration averaging 36 mg/1. The
BODs concentration (36 mg/1) in the influent during
Loading Period III was much higher than normally
obtained from a well operated secondary wastewater
treatment plant. The 0.17 mm field filters produced
an effluent with a BOD, concentration of less than 5
mg/1 on all days of operation when loaded at 0.6
mgpad or less. Effluent BOD5 concentrations for the
filter loaded at 0.7 mgpad exceeded 5 mg/1 on only 2
days out of 69 days of operation and the maximum
value in the effluent was 6.7 mg/1. The average BOD,
in filter A7 effluent was 3.7 mg/1 for the entire period
of 69 days. A loading of 0.8 mgpad produced an
effluent of slightly poorer quality but still reduced
the BOD5 to a mean value of 4.1 mg/1. Thus, most
properly operated secondary treatment plants in the
state would be able to meet Class "C" discharge
standards with the addition of intermittent sand
filtration. Even under such heavy BOD5 loadings as
studied during Loading Period III in the laboratory,
reductions were greater than 80 percent for the 0.17
mm (.0067 inch) sand at all hydraulic loading rates.
Middlebrooks et al. (1972) reported the ef-
fluent characteristics of 11 existing wastewater treat-
ment plants in the State of Utah, some of which were
heavily overloaded. Seven were trickling filters and
five were wastewater stabilization ponds. Assuming
that equivalent' reductions in BOD5, suspended solids,
and coliform organisms would be obtained by inter-
mittent sand filtration on all types of secondary
treatment plant effluents, seven of the eleven plants
would be able to meet the BOD5 standards for Class
"C" discharged waters by adding intermittent sand
filters. If the overloading were corrected and the
plants operated properly, all 11 plants could meet
Class "C" discharge standards by installing inter-
mittent filters. Several of these plants were serving
metropolitan areas, and it may not be feasible to
utilize intermittent filters because of land limitations
and economic constraints usually associated with
metropolitan areas.
On the basis of the mean total coliforms per
100 ml reported, five of the eleven Utah wastewater
treatment facilities would be able to meet Class "C"
discharge standards by the addition of intermittent
sand filtration. If the plants were not overloaded, in
all probability the coliform requirements could be
met in all 11 plants. Again, the addition of a
disinfection step would aid materially in meeting
coliform removal requirements as well as eliminate
the contributions to a downstream algae bloom
problem.
Class "C" discharge requirements for pH value
and dissolved oxygen are normally easily met by
secondary treatment, and the intermittent sand filtra-
tion of these effluents further refines effluents. The
pH values of the Logan lagoon effluents were
approximately equal to a value of 9. When passed
through the filters, the pH was reduced to values
approximately within the limits imposed. Six to nine
mg/1 of dissolved oxygen were readily produced by
intermittent sand filtration which also meets Class
"C" water standards.
Cost estimate
A general approach was taken in the prepara-
tion of the cost estimates for an effluent polishing
intermittent sand filter process. The estimates shown
Table 17. Class "C" stream standards for the State of Utah (Middlebrooks et al., 1972).
Parameter
Concentration or Unit
pH
Total Coliform, Monthly Arithmetic Mean
Fecal Coliform, Monthly Arithmetic Mean
BOD,, Monthly Arithmetic Mean
Dissolved Oxygen
Chemical and Radiological
6.5 - 8.5
5,000/100 ml
2,000/100 ml
5 mg/1
> 5.5 mg/1
PHS Drinking Water Standards
-------
66
Middlebrooks and Marshall
for initial plant construction outlays are of a higher
degree of reliability than the values estimated for
operation. Much better estimates of operational
expenses will be afforded by the future prototype
study.
The in-place total construction cost estimates
were prepared through the aid of a local consulting
engineering firm. Thus, they are representative of the
outlay necessary to construct a typical intermittent
sand filter process in the intermountain area during
1973.
The construction and annual operation cost
estimate shown for the 15 mgd Logan City facility is
not as general in nature as the other estimates. This
estimate was based upon two assumptions: One, the
process would be located such that pumping of the
applied effluent was not necessary; two, additional
cost for land is not necessary as the final one and a
half existing tertiary ponds would be drained and the
polishing filters would be located within these
boundaries. Also, the 15 mgd Logan stabilization
pond system is presently the largest existing facility
of this type in Utah. A cost estimate for this facility
will then provide an expense evaluation for the entire
range of stabilization pond systems in Utah.
A large difference was found between locally
available filtering media and specially prepared media,
so an economic evaluation of the two types of media
was made. In this case, the 0.17 mm (.0067 inch) size
media was locally available and the 0.35 mm (.0137
inch) and the 0.72 mm (.0283 inch) sizes were
specially prepared. The specially prepared media in
this area was found to be more than five times more
costly than the locally available media. Based on the
assumptions that the 0.17 mm (.0067 inch) locally
available media was approximately two and one-half
times more costly to operate than the 0.72 mm
(.0283 inch) media, the 0.17 mm (.0067 inch) media
was found to be the economic choice for a 1 mgd and
the 15 mgd existing lagoon system.
The construction costs determined in Estimates
1 through 4, Table 18, reflect a paired bed operation
designed at 300,000 gpad (459.5 m3/hectare-day)
and 800,000 gpad (1225.4 m3/hectare-day) and the
application of the effluent to the filter in less than 90
minutes. It was assumed that in a municipal construc-
tion effort such as this, at least 75 percent of the
construction cost would be funded by federal aid.
Also, costs without federal assistance are reported.
The construction costs for Estimate 5, Table
18, reflect an optimum design situation for a 1 mgd
facility. Conditions considered optimum are
minimum bed area operated under scheduled rota-
tion, no pumping required for dosing, locally avail-
able media, and plastic bed liners not required. Under
these conditions with the aid of federal funds, a filter
process designed at 800,000 gpad (1225.4 m3/hec-
tare-day) for a 1 mgd facility would cost the
community $14,500 to construct.
Sand or media expense is approximately 25
percent of the total construction cost. Also, the
plastic liner for the bed is approximately 25 percent
of the total construction cost. Whether or not the
liners are a required expense in constructing effluent
polishing intermittent sand filters will depend on the
specific conditions and regulations governing each
location and installation of this process. As shown in
Estimate 5, considerable savings are made by not
installing the plastic bed liners. In rural areas, land
costs for this process are less than 5 percent of the
total construction costs.
Costs per million gallons of effluent produced
are shown in Table 18 with and without federal
assistance. Without federal funds, the costs are greatly
increased. The effect of an optimum condition
application is noted by the cost of $16 per million
gallons (Table 18). Combined effects of larger scale
operation and specific application, which in this case
held conditions near optimum, are noted by the $15
per million gallons cost for the Logan City facility.
Table 18. Estimated cost per million gallons of filtrate produced by various designs of an effluent polishing
intermittent sand filter process.
Application
conditions
General (Estimate 1)
General (Estimate 2)
General (Estimate 3)
Specific (Estimate 4)
Optimum (Estimate 5)
Design
Flow
Rate
1 mgd
1 mgd
1 mgd
15 mgd
1 mgd
Design
Hydraulic
Loading
Rate
0.3 mgad
0.8 mgad
0.8 mgad
0.6 mgad
0.8 mgad
Effective
Sand Size
.17mm
.17mm
.72mm
.17mm
.17mm
Cost With Cost Without
Federal Federal
Assistance Assistance
$/ 1 0 3gallons $/ 1 03 gallons
$47
$33
$46
$15
$16
$115
$ 61
$145
$ 48
$ 26
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 67
Finally, for the general applications estimates when a
1 mgd plant constructed with 0.17 mm (.0067 inch)
effective size locally available media is compared to
one constructed of a specially prepared media. The
cost of operation and media using the 0.17 mm
(.0067 inch) effective size sand designed for a
hydraulic loading rate of 0.3 mgd is essentially equal
to the operation and media costs for the coarser 0.72
mm (.0283 inch) effective size specially produced
sand. If the 0.72 mm (.0283 inch) effective size
specially prepared sand filter were designed using
much higher loading rates and optimum conditions,
the cost per million gallons for this particular sand
would decrease to the point where it would become
economically competitive.
From the present understanding of the opera-
tion of effluent polishing intermittent sand filters, a
cost ranging between $15 to $47 per million gallons
can be assumed to be representative of this process.
Table 19 lists alternative methods to meet Class "C"
water standards and their estimated costs as reported
by Middlebrooks et al. (1972). Based on these values,
the earlier stated cost for an effluent polishing
intermittent sand filter process is quite competitive.
There are many avenues of approach that may be
taken to produce the same high quality effluent of
this process at even lower expense. Coupling this
possibility with the fact that a majority of the
existing wastewater effluents in Utah can be upgraded
to meet Class "C" water standards by the addition of
this process, intermittent sand filtration of waste-
water effluents has been found to be an economically
feasible method of wastewater effluent polishing.
Summary and Conclusions
The major objective of this study was to
evaluate the performance of the intermittent sand
filter and to determine if it was capable of upgrading
existing wastewater treatment plants in the State of
Utah to meet Class "C" water quality standards.
Table 19. Cost of alternative methods of polishing
wastewater effluents (Middlebrooks et al.,
1972).
Method
Cost per
106 gal.
Chemical treatment (solids contact) $60-130
Granular or mixed media filtration w/chem $50
Dissolved air flotation $110
Electrodialysis $200
Microstraining $18
Hydraulic loading rate was found to have little
effect on any of the parameters studied in the
laboratory portion of the study. In the field experi-
ments at much higher hydraulic loading rates and
varying algal concentrations, suspended and volatile
suspended solids removal appeared to decrease with
an increase in hydraulic loading. Although significant
quantities of applied algae were removed by filtra-
tion, cells were found to pass the entire bed depth.
Sand size was found to have a general effect on the
quality of the effluent produced by filtration. Sand
size was also found to be related to the time of
operation before plugging occurred. It was concluded
that intermittent sand filtration was capable of
upgrading a majority of the existing wastewater
effluents in Utah to meet Class "C" water standards.
In addition to the above, the following general
observations and conclusions were made:
1. Smaller effective size sands better oxidize
nitrogen compounds.
2. Hydraulic loading rate has little effect on
ability of the sand filter to oxidize nitrogen at the
loading rates studied in the laboratory.
3. The nitrogen form which is being oxidized
is principally that of ammonia.
4. After establishing equilibrium with the
media, intermittent sand filters do not remove a
significant quantity of dissolved phosphorus com-
pounds.
5. Hydraulic loading rate has little effect on
BOD5 removal when secondary wastewater effluent is
applied to intermittent sand filters with bed depths of
30 inches.
6. BOD removal increased as the effective size
of the sand decreased. The 0.17 mm effective size
sand filters produced a project low mean effluent
BOD5 concentration of 1.6 mg/1 at the 0.4 mgpad
loading rate and a high value of 4.1 mg/I at 0.8
mgpad. The project mean effluent BOD5 concentra-
tion for the 0.72 mm effective size sand filters ranged
from 5.0 to 5.5 mg/1 for the 0.4,0.5, and 0.6 mgpad
hydraulic loading rates.
7. BOD5 removal was independent of the
applied BOD value at the concentrations studied in
the laboratory.
8. Viable algal cells passed the entire depth of
all the filter sands studied.
9. Hydraub'c loading rate did not affect the
algae or suspended solids removal efficiency at the
-------
68 Middlebrooks and Marshall
100,000 (153.4 m3/hectare-day), or 200,000 (153.4
m3/hectare-day), or 300,000 (454.9 m3/hectare-day)
gallons per acre-day loadings employed in the labora-
tory study. The effects of hydraulic loading rate on
SS removals in the field studies were inconclusive
because of the large quantities of fines washed from
the filters, but volatile suspended solids removals did
indicate a reduction in removal efficiency as the
hydraulic loading rate was increased.
10. Smaller effective size sands produced bet-
ter algal or suspended and volatile suspended solids
removals.
11. Sand size was not a significant factor in
algal removal at applied algal concentrations of 15
and 30 mg/1, but was significant when the concentra-
tion was increased to 45-50 mg/1 in both the
laboratory and field filters.
12. Intermittent sand filtration produced a 90
percent reduction in the total coliform count in the
laboratory filters.
13. Coliform removal was independent of the
hydraulic loading rates employed in the laboratory
filters.
14. Total bacterial counts as measured by the
standard plate count apparently was not reduced by
any of the sands studied.
15. Filter plugging causes no decline or im-
provement in the effluent BOD at or near the time of
plugging.
16. Immediately before plugging occurred in
the laboratory filter, the filter effluent suspended
solids concentrations were approximately zero. As
the filter operates with time, the suspended solids
removal efficiency increases reaching a maximum
point at the time of plugging. This did not occur in
the field, but if fines were washed from the filter
before placing it in operation, it is likely that a similar
pattern would occur.
17. At hydraulic loading rates of 0.4 to 0.6
mgpad the 0.17 mm effective size sand filters will
operate approximately 100 days before cleaning is
required when receiving a lagoon effluent containing
a mean suspended solids concentration of 20 mg/1.
18. At loading rates of 0.7 and 0.8 mgpad the
0.17 mm filters will operate 32 consecutive days
before requiring cleaning when receiving lagoon ef-
fluent containing a mean suspended solids concentra-
tion of 42 mg/1.
19. Laboratory filters containing sands of 0.72
mm effective size operated 175 consecutive days
before plugging when dosed with a lagoon effluent
containing a mean suspended solids concentration of
51 mg/1 at a rate of 0.3 mgpad.
20. Field filters containing 0.72 mm effective
size sand operated 137 consecutive days before
terminating the study without plugging when loaded
at 0.4, 0.5, and 0.6 mgpad with a lagoon effluent
containing a mean suspended solids concentration of
25 mg/1.
21. If operated and loaded properly, all exist-
ing wastewater treatment plants in the State of Utah
could be upgraded by intermittent sand filtration to
meet Class "C" state standards.
22. Based upon current cost figures it appears
that an effluent polishing intermittent sand filter
process can be constructed and operated for a cost
ranging between $15 to $47 per million gallons of
filtrate.
Literature Cited
American Society of Civil Engineers and Federation of
Sewage and Industrial Wastes Association. 1959. A
Joint Conference on Sewage Treatment Plant Design.
New York.
Borchart, Jack A., and Charles R. O'Melia. 1961. Sand
filtration of algal suspensions. Journal of the American
Water Works Association 53(12):1493-1502.
Calaway, W. T., W. R. Carroll, and S. K. Long. 1952.
Hetetotiophic bacteria encountered in intermittent
sand filtration of sewage. Sewage and Industrial Wastes
Journal 24(5):642-653.
Folkman, Yair, and Alberto M. Wachs. 1970. Filtration of
Chtorella through dune-sand. Journal of the Proceed-
ings of the American Society of Civil Engineers,
Sanitary Engineering Division, 96(SA3):675-690. June.
Furman, Thomas De Saussure, Wilson T. Calaway, and
George R. Grantham. 1949. Intermittent sand filters-
multiple loadings. Sewage and Industrial Wastes Journal
27(3):261-276.
Grantham, G. R., D. L. Emerson, and A. K. Henry. 1949.
Intermittent sand filter studies. Sewage and Industrial
Wastes Journal 21(6):1002-1015.
Ives, Kenneth J, 1961. Filtration of radioactive algae. Journal
of the Proceedings of the American Society of Civil
Engineers, Sanitary Engineering Division, 87(SA3):
23-37. May.
Marshall, G. R., and E. Joe Middlebrooks. 1974. Intermittent
sand filtration to upgrade existing wastewater treat-
ment facilities. PRJEW115-2, Utah Water Research
Laboratory, College of Engineering, Utah State Univer-
sity, Logan, Utah.
-------
Stabilization Pond Upgrading with Intermittent Sand Filters 69
Middlebrooks, E. Joe, James H. Reynolds, Gerald L. Shell,
and Norman B. Jones. 1972. Modification of existing
wastewatei treatment plants in Utah to meet Class "C"
water quality standards. Joint Meeting, Intel-mountain
Section, American Water Works Association and Utah
Water Pollution Control Association. September 23-24,
Provo, Utah. 32 p. (Mimeographed).
Pincince, Albert B., and Jack E. McKee. 1968. Oxygen
relations in intermittent sand filtration. Journal of
Proceedings of the American Society of Civil Engineers,
Sanitary Engineering Division, 89(SA6):1093-1119.
December.
Solorzano, L. 1969. Determination of ammonia in natural
waters by the phenolhypochlorite method. Limnology
and Oceanography 14:799-800.
Standard Methods for the Examination of Water and Waste
Water, Thirteenth Edition. 1971. American Public
Health Association, New York. 874 p.
Strickland, J. D. H., and T. R. Parsons. 1968. A practical
handbook of seawater analysis. Fisheries Research
Board of Canada, Ottawa, Bulletin Number 167. 311 p.
-------
INTERMITTENT SAND FILTRATION TO UPGRADE
LAGOON EFFLUENTS-PRELIMINARY REPORT
J. H. Reynolds, S. £ Harris. D. Hill,
D. S. Filip, andE. J. Middlebrooks1
Introduction
Nature of the problem
Approximately 90 percent of the waste-
water lagoons in the United States are located in
small communities of 5,000 people or less. These
communities, many with an average daily wastewater
flow rate of only 175,000-200,000 gallons, do not
have the resources to keep men at the lagoon sites
throughout the day. A high degree of technical
knowledge is usually lacking in these communities.
Often only periodic inspection or maintenance is
carried out by the general municipal employees.
Therefore, the development of a relatively inexpen-
sive, low operation and maintenance method for pol-
ishing lagoon effluent to meet the requirements of
PL 92-500 is needed.
There are many sections of the country that are
still fortunate to be surrounded by large areas of open
and relatively inexpensive land. It was originally due
to this reason that many of these communities
adopted waste stabilization lagoons as a means of
wastewater treatment. Although this treatment
scheme requires large tracts of land, the important
consideration was that it gave a satisfactory effluent
for minimum cost and maintenance. But now a better
quality effluent is necessary. If small cities and towns
are to economically produce a higher quality effluent,
some form of treatment must be utilized that will
continue to take advantage of the large areas of
relatively inexpensive land surrounding these com-
munities. One method of treatment that capitalizes
on the availability of large land areas is intermittent
sand filtration.
In most areas of the country where intermittent
sand filtration has been used, the lack of large
J. H. Reynolds is Assistant Professor of Civil and
Environmental Engineering, Utah Water Research Labora-
tory; S. E. Harris and D. Hill are graduate students in Civil
and Environmental Engineering, D. S. Filip is Research
Biologist, Utah Water Research Laboratory; and E. J.
Middlcbrooks is Dean of Engineering, Utah State University,
Logan, Utah.
inexpensive tracts of land was a major factor con-
tributing to a decline in use. Thus, the relatively
inexpensive tracts of rural land available near many
lagoon sites is a definite asset. Intermittent sand fil-
tration becomes even more economically attractive if
filter media are available locally.
Objectives
The objective of this study was to evaluate and
compare the performance of a full-scale intermittent
sand filter with results obtained using laboratory and
pilot field scale intermittent sand filters as a polishing
process that would upgrade existing wastewater treat-
ment facilities. Particular attention was directed
toward ascertaining the effectiveness of the inter-
mittent sand filter as a means of removing the highly
variable quantities of algae present in stabilization
ponds during the warmer months of the year. The
ultimate objective is to develop design criteria for
intermittent sand filters that will consistently
produce an effluent of a quality that would meet
stringent water quality standards.
Previous Investigations
Historical background
Use of intermittent sewage filtration began in
this country in the late nineteenth century. The first
intermittent sewage filters were put in use in 1889 in
Massachusetts. For many years their use was centered
in the New England area. By 1945, approximately
450 intermittent filter plants were in operation in this
country. But later reports showed a decrease to 398
in use by 1957. It was also noted (ASCE and FSIWA,
1959) that 94 percent of those still in use by 1957
were serving communities with populations under
10,000.
The intermittent sewage filter has long been
known to have the ability to produce effluents of
relatively high quality as did the slow sand filter for
culinary waters. The decline of intermittent sewage
filters was related to the same factors that caused the
decline of slow sand filters-an increase in quantity of
71
-------
72 Reynolds, Harris, Hill, Filip, Middlebrooks
water to be filtered due to a growing population, and
to the rising costs of land.
Intermittent sand filtration, as noted earlier,
began in the New England area of this country.
Located in Lawrence, Massachusetts, was the
Lawrence Experiment Station at which many of the
first studies on intermittent sand filtration were
accomplished. This region of the country was ideal
for the application of such a process as intermittent
sand infiltration. Many small rural communities were
developing to the point that it was necessary to treat
their wastewater at a central plant which was
economical for the small town. Land to build the
filters upon was readily available at reasonable rates
and there was also abundant quantities of well graded
bank run sand available. These conditions encouraged
efforts in research at the Lawrence Experiment
Station to improve the intermittent sand filter. As a
result of this experimentation and success, the use of
intermittent sand filters increased.
Following World War II, many people found
the mild climate and sparsely populated land of
Florida an ideal place to live following retirement.
Large numbers of small residential centers such as
isolated tourist courts, motels, trailer parks, drive-in
theaters, consolidated schools, and housing develop-
ments began to spring up all over Florida. It was soon
realized that an economic method of sewage treat-
ment would be necessary for these small com-
munities. Thus, the study of intermittent sand filtra-
tion was undertaken at the University of Florida at
Gainesville, (Calaway et al., 1952; Furman et al.,
1949; and Grantham et al., 1949). Much of the
modern day knowledge on intermittent sand filters
has come out of the studies carried out at Gainesville.
All of this work was concentrated on treating raw or
primary effluent wastewaters. A detailed review of
the University of Florida study and other in-
vestigations dating back to 1908 has been presented
by Marshall and Middlebrooks (1974).
Laboratory and pilot scale studies
Marshall and Middlebrooks (1974) evaluated
the performance of laboratory and pilot scale inter-
mittent sand filters to determine if the process was
capable of upgrading existing wastewater treatment
plants in the State of Utah to meet Class "C" water
quality standards (BOD ^ 5 mg/1, pH = 6.5-8.5, total
coliform g 5,000/100 ml, fecal coliform ^
2,000/100 ml, and D.O. > 5.5 mg/1). Effective size of
the sand, hydraulic loading rate, and algal concentra-
tions were the variables studied. Hydraulic loading
rate was found to have little effect on any of the
parameters studied in the laboratory portion of the
study. In the field experiments at much higher
hydraulic loading rates and varying algal concentra-
tions, suspended and volatile suspended solids re-
moval appeared to decrease with an increase in
hydraulic loading. Although significant quantities of
applied algae were removed by filtration, cells were
found to pass the entire bed depth. Sand size was
found to have a general effect on the quality of the
effluent produced by filtration. Sand size was also
found to be related to the time of operation before
plugging occurred. BOD removal increased as the
effective size of the sand decreased. The 0.17 mm
effective size sand filters produced a project low
mean effluent BOD5 concentration of 1.6 mg/1 at the
0.14 mgad loading rate and a high value of 4.1 mg/1 at
0.8 mpd. The project mean effluent BOD5 con-
centration for the 0.72 mm effective size sand filters
ranged from 5.0 to 5.5 mg/1 for the 0.4, 0.5, and 0.6
mgad hydraulic loading rates. Hydraulic loading rate
did not affect the algae or suspended solids removal
efficiency at the 100,000 (153.4 m3/hectare-day), or
200,000 (306.8 m3/hectare-day), or 300,000 (454.9
m3/hectare-day) gallons per acre-day loadings em-
ployed in the laboratory study. The effects of
hydraulic loading rate on SS removals in the field
studies were inconclusive because of the large
quantities of fines washed from the filters, but
volatile suspended solids removals did indicate a
reduction in removal efficiency as the hydraulic
loading rate was increased. Immediately before plug-
ging occurred in the laboratory filter, the filter
effluent suspended solids concentrations were
approximately zero. As the filter operated with time,
the suspended solids removal efficiency increased
reaching a maximum point at the time of plugging.
This did not occur in the field, but if fines were
washed from the filter before placing it in operation,
it is likely that a similar pattern would occur. At
hydraulic loading rates of 0.4 to 0.6 mgad the 0.17
mm effective size sand filters were found to operate
approximately 100 days before cleaning is required
when receiving a lagoon effluent containing a mean
suspended solids concentration of 20 mg/1. At loading
rates of 0.7 and 0.8 mgad the 0.17 mm filters will
operate 32 consecutive days before requiring cleaning
when receiving lagoon effluent containing a mean
suspended solids concentration of 42 mg/1. Based
upon current cost figures it appears that an effluent
polishing intermittent sand filter process can be
constructed and operated for a cost ranging between
$15 to $47 per million gallons of filtrate. It was
concluded that intermittent sand filtration was cap-
able of upgrading a majority of the existing waste-
water effluents in Utah to meet Class "C" water
standards.
Experimental Procedures
Experimental facility
The experimental facility is located at the
Logan Municipal Sewage Lagoons as shown in Figure
1. The facility consists of six, 25 ft x 36 ft (900 sq ft
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents
73
Figure 1. Location map.
surface) intermittent sand filters. A cross section of a
typical filter is shown in Figure 2. The soil embank-
ment around each filter is constructed of bank run
granular fill material. Each filter contains 1 foot of
graded gravel (1/4 in max. diameter to 1 1/2 in max.
diameter) and 3 feet of pit run concrete sand. The
sand has an effective size of 0.170 mm and a
uniformity coefficient of 9.74. A sieve analysis of the
sand is shown in Table 1. The filters are lined with a
vinyl liner (10 mm) to prevent infiltration of subsur-
face groundwater or exfiltration of filter influent.
The filter construction provides 3 feet of freeboard
above the sand surface.
The filters are loaded once daily with either
tertiary or secondary effluent from the Logan
Municipal Sewage Lagoon system (depending on
Table 1. Sieve analysis of filter sand.3
U.S. Sieve
Designation
Number
3/8"
4
10
40
100
200
ae = 0.170 mm;
Size of
Opening
(mm)
3/8"
4.76
.
0.42
0.149
0.074
; u = 9.74.
Percent
Passing
(%)
100.0
92.1
61.7
27.0
6.2
1.7
which effluent has the highest suspended solids
concentration). The hydraulic loading of each filter is
accomplished in less than 30 minutes. The loading
rates being studied are 0.2, 0.4, 0.6,0.8,1.0, and 1.2
mgad. When the total amount of applied influent to a
filter does not drain through the filter in 24 hours,
the filter is considered to be plugged and is taken out
of service and cleaned.
Geaning is accomplished by removing the top
1/2 to 2 inches of filter sand. The sand is stockpiled
and will eventually be washed. The organic washing
from the sand will be recycled to the primary lagoon
and the clean filter sand will be replaced in the filter.
Sampling and analyses
Samples of filter influent and effluent are
collected and analyzed for suspended solids and
'volatile suspended solids three times a week, bio-
chemical oxygen demand (BODc) once a week and
chemical oxygen demand (COD), total phosphorus,
orthophosphorus ammonia, nitrite, pH, temperature,
and dissolved oxygen are monitored once each week.
The effluent samples are collected 2 hours after each
filter is loaded. The procedure employed for each
analysis is shown in Table 2.
Results and Discussion
General
Data collection began on July 12, 1974, after
the filters had been "washed" to remove dirt and fine
-------
74 Reynolds, Harris, Hill, Filip, Middlebrooks
inorganic material generated by the filter con-
struction. Data collection continued until a filter
plugged and was taken out of service. The data
presented in this report were collected during the first
experiment period (July 12, 1974, to August 22,
1974) of the project. All data collected during the
report period Jiave been averaged and these average
values are reported in Table 3. The number of
individual data points averaged depends on the length
of the particular filter run. However, in no case were
fewer than three data points used to obtain an
average value.
Algae
The characteristics of the influent algal popula-
tion are shown in Table 4. The predominant algae are
small coccoid blue-green, which have been tentatively
-LINER
INFLUENT
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents
75
Table 2. Procedures for analysis performed.
Analysis
Procedure
Ref. No.
Biochemical Oxygen Demand
Chemical Oxygen Demand
Suspended Solids
Volatile Suspended Solids
Total Phosphorus
Orthophosphorus
Ammonia
Nitrite
Nitrate
Dissolved Oxygen
Temperature
pH
Standard Methods
Standard Methods
Standard Methods
Standard Methods
EPA Methods
Strickland & Parsons (Murphy-Rfley Technique)
Solorzano (Indophenol)
Strickland and Parsons (Diasotization Method)
Strickland & Parsons (Cadmium-Reduction
Method)
Standard Methods
Standard Methods
Standard Methods
APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
EPA, 1971
Strickland & Parsons, 1968
Solorzano, 1969
Strickland & Parsons, 1968
Strickland & Parsons,, 1968
APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
Table 3. Average of all samples collected during the experimental period.
Loading
Rate in
mgad
Influent
0.2
0.4
0.6
0.8
1.0
1.2
BOD5
mg/1
8.1
2.4
1.7
2.3
3.5
2.8
4.3
COD
mg/1
69.7
42.1
27.8
27.5
40.6
39.8
49.7
Sus-
pended
Solids
mg/1
26.1
6.8
3.7
5.5
7.2
7.1
4.8
Volatile
Sus-
pended
Solids
mg/1
16.9
0.9
1.0
1.4
0.7
1.0
0.8
Total
Phos-
phorus
mg/1
2.082
1.756
1.595
1.767
1.863
1.980
1.776
Orthcc
Phos-
phate
mg/1'
1.754
1.695
1.458
1.644
1.683
1.717
1.657
NH3-N
mg/1
2.469
0.166
0.197
0.293
0.322
0.486
0.541
N02-N
mg/1
0.025
0.083
0.025
0.055
0.090
0.160
0.154
N03-N
mg/1
0.100
4.670
4.936
4.985
4.372
3.664
3.383
PH
8.8
8.0
8.1
8.0
7.9
8.1
8.1
Temp.
°C
23.2
23.6
24.4
23.7
25.0
25.1
24.0
Dis-
solved
Oxygen
mg/1
4.2
6.2
6.1
5.9
5.7
5.0
4.8
Algal
Mass
Removed
Kg
a
21.988
21.538
26.108
18.783
19.008
12.336
aNot applicable.
identified as Aphanocapsa sp. The concentration of
this particular alga has increased rapidly in recent
weeks. The unknown unicellular green alga reported
in Table 4 has been tentatively identified as the
palmelloid state of Chlamydomonas sp.
The algal population is much different than
that employed in previous laboratory and field scale
intermittent sand filter experiments (Marshall and
Middlebrooks, 1974). The algal population used in
earlier experiments was predominantly
Chlamydomonas sp.
Length of filter run
The length of filter run for each hydraulic
loading rate is shown in Figure 3. As expected the
length of filter run is directly related to the hydraulic
Table 4. Algae present in influent.
Alga
Blue Green Coccoid
Oscillatoria sp.
Mcrocystis sp.
Navicula sp.
Unknown Pennate
Pediastrum sp.
Schoideria sp.
Unknown Unicellular
Green
Unknown Euglenoid
Total
Zooplankton
Cells per ml
Aug. 6
33,920
53
0
8,480
1,272
1,696
53
0
53
45,527
178
Aug. 9
92,928
132
0
5,016
1,696
0
66
0
66
99,904
123
Aug. 14
100,188
858
330
17,688
2,508
0
396
1,254
330
123,552
186
-------
76 Reynolds, Harris, Hill, Filip, Middlebrooks
loading rate. The length of filter run varied from 14
days with a hydraulic loading rate of 1.2 mgad to 42
days with a hydraulic loading rate of 0.2 mgad.
These lengths of filter run are somewhat shorter
than those reported earlier (Figure 4) for laboratory
and pilot scale filters (Marshall and Middlebrooks,
1974). However, the average influent suspended
solids concentration for previous investigations was
20.0 mg/1 while for the present study the average
influent suspended solids concentration was 26.1
mg/1 with a range of 10.9 mg/1 to 72.1 mg/1.
The time of day at which the filters are loaded
may significantly effect the length of filter run.
Filters which are loaded early in the morning and
have influent standing on them throughout the entire
daylight period may experience a tremendous amount
of algal growth in the liquid above the filter itself. An
experiment was conducted in which 6-inch diameter
plexiglass columns were filled with filter influent and
placed on the filter surface. The bottoms of the
columns were sealed to prevent concentration of the
algae as the water percolated through the sand and
the water level in the column was held at the same
level as the water on the filter by removing water
from the column every hour. The experiment was
conducted with three columns which permitted light
penetration and three dark columns which did not
permit light penetration to use as a control. The
suspended solids concentration and the volatile sus-
pended solids concentration of the columns were
monitored with time. The results are recorded in
Table 5 and shown graphically in Figure 5. The water
remained on the surface of the filter for over 12
hours after loading and at the end of the daylight
period approximately 1 foot of influent water re-
mained on the filter surface. The suspended solids
concentration had increased from 77.1 mg/1 at 1 hour
after loading to 222.4 mg/1 at 12 hours after loading.
This indicates that the average algal concentration
filtered may have been 45 percent greater than the
influent measurements indicate. Thus, the filter per-
formance data presented in the report may be
extremely conservative.
As shown by Figure 5 and Table 5, the increase
in the volatile suspended solids concentration in the
50
40
IS 30
Q.
O
O
CO
20
Q 10
42
28
26
21
19
14
0.2 0.4 0.6 0.8 1.0
LOADING RATE, mgad
1.2
Figure 3. Days of operation before plugging.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents 77
liquid standing on the filter during daylight hours is
similar to the increase in suspended solids concentra-
tion. The volatile suspended solids concentration
increased from 55.29 mg/1 at 1 hour after loading the
filter to 109.03 mg/1 at 12 hours after loading the
filter. This represents an increase in volatile sus-
pended solids concentration of 97 percent. This
further indicates the conservative nature of the
performance data presented in this report.
These results indicate that the length of filter
run could be substantially increased by either loading
the filters at night after sundown or by covering the
filters to prevent photosynthesis.
An attempt was made to determine the actual
mass of suspended matter removal by each filter
before plugging. This was accomplished by multiply-
ing the influent suspended solids concentration by
the volume of liquid filtered by each filter daily.
Because influent suspended solids were not moni-
tored daily, it was necessary to extrapolate values for
those days without influent suspended solids data by
averaging the data of the day before and following
the day without data. The results are reported in
Table 3 and shown graphically in Figure 6. Ad-
mittedly, this is only an approximation, but it is
superior to not analyzing the data.
Figure 6 clearly indicates that the 0.6 mgad
loading rate removed a substantially greater total
mass than did any of the other filters. A possible
explanation for this phenomenon is that these filters
are a biological system, and much of their treatment
capability is related to aerobic bacteria (see section
on nutrient removal). Thus, like any other biological
system, there exists an optimum organic (nutrient)
loading rate. Below this optimum rate, the organisms
receive insufficient nutrients to establish a maximum
population. Above this optimum rate, the organisms
receive too much organic matter and anaerobic
conditions exist which restrict filter performance.
Effluent quality with time
When the filters were initially placed in opera-
tion, the effluent suspended solids concentration (i.e.,
34.6 mg/1 at 0.4 mgad) far exceeded the influent
125
100
2 75
50
CO
o 25
0.4 0.5 0.6 0.7 0.8
LOADING RATE IN mgad
Figure 4. Days of operation for field scale filters with 0.17 mm sand.
0.9
-------
78 Reynolds, Harris, Hill, Filip, Middlebrooks
Table 5. Algal growth on filters with time.
Time
in
Hours
1.0
2.3
3.6
5.0
6.0
8.0
10.0
12.0
Average
Algal
Suspended
Solids
(mg/1)
77.1
81.3
92.9
90.0
93.3
102.0
164.0
222.4
111.6
Growth3
Volatile
Suspended
Solids (mg/1)
55.29
56.32
62.33
63.19
66.98
74.94
80.48
109.03
71.07
Suspended
Solids
(mg/1)
75.2
81.4
77.4
73.6
73.1
69.2
68.9
78.9
74.7
Control3
Volatile
Suspended
Solids (mg/1)
49.99
55.44
50.55
49.23
53.24
49.23
48.12
52.19
50.99
aAverage of three columns.
250
E 200
CO
9 150
o
CO
g 100
o
LU
Q.
CO
CO
50
EXPERIMENTAL SUSPENDED SOLIDS
CONTROL SUSPENDED SOLIDS
EXPERIMENTAL VOLATILE SS
CONTROL VOLATILE SS
-£r &-•£*
468
TIME IN HOURS
10
12
14
Figure 5. Algal growth on filters with time.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents 79
suspended solids (i.e., 24.9 mg/1). However, the
effluent volatile suspended solids concentration (i.e.,
2.5 mg/1 at 0.4 mgad) was substantially less than the
influent volatile suspended solids concentration (i.e.,
17.8 mg/1). Essentially, the high initial effluent
suspended solids concentration was composed of
inorganic material being "washed" from the filters.
This material had a fine sand texture and was
probably very fine sand, dirt, and grit introduced into
the filter system by the filter construction process.
After several days of operation, this phenomenon
ceased.
The effluent suspended solids of each filter were
monitored with time after loading on three separate
occasions to determine if variations existed. A typical
plot is shown in Figure 7. It was found that the
effluent suspended solids concentration peaks be-
tween 20 and 30 minutes after loading. This is
probably due to the high velocity through the filter
caused by the maximum head on the filter immedi-
ately following loading. However, on all effluent
samples taken with time the volatile suspended solids
concentration was less than 1.0 mg/1 (influent VSS »
17.0 mg/1). Thus, the variation in effluent suspended
solids is probably caused by "filter washing."
Because of this variation in effluent quality with
time, it was decided to sample the effluent 2 hours
after loading.
Suspended solids and volatile
suspended solids
The average effluent suspended solids concen-
tration for each hydraulic loading rate is reported in
Table 3, and shown graphically in Figure 8. The
average influent suspended solids concentration was
26.1 mg/1 while the average effluent suspended solids
concentration varied from 3.7 mg/1 (0.4 mgad) to 7.2
mg/1 (0.8 mgad). However, a maximum influent
suspended solids concentration of 72.1 mg/1 resulted
in effluent suspended solids concentration of less
than 4.0 mg/1 for the 0.2 mgad and the 0.4 mgad
hydraulic loading rates (all other filters were plugged
at this time).
In general, the filtered effluent suspended solids
concentration increased slightly with an increase in
the hydraulic loading rate.
The average effluent volatile suspended solids
concentration for each hydraulic loading rate is
25
CD
§20
o
o
5 15
< 10
§ 5
<
i
0 0.2 0.4 0.6 0.8 1.0
LOADING RATE IN mgad
Figure 6. Total mass removed by each filter before plugging.
1.2
1.4
-------
80 Reynolds, Harris, Hill, Filip, Middlebrooks
reported in Table 3, and shown graphically in Figure
9. The average influent volatile suspended solids
concentration was 16.9 mg/1 while effluent volatile
suspended solids concentrations were all less than 1.5
mg/1. A maximum influent volatile suspended solids
concentration of 63.4 mg/1 resulted in an effluent
volatile suspended solids concentration of 1.2 mg/1
for both the 0.2 mgad and the 0.4 mgad loaded filters
(all other filters were plugged at the time).
In general, the filtered effluent volatile sus-
pended solids concentration appears to be in-
dependent of the hydraulic loading rate. Also, these
results indicate that the filters remove over 90
percent of the applied volatile suspended solids.
BODS and COD
The average biochemical oxygen demand
(BOD5) of the filtered effluent for each hydraulic
loading rate is reported in Table 3, and shown
graphically in Figure 10. The average influent BOD5
was 8.1 mg/1 while the average effluent BOD5 ranged
from 1.7 mg/1 for a hydraulic loading rate of 0.4
mgad to 4.3 mg/1 for a hydraulic loading rate of 1.2
mgad. The maximum influent BOD, applied to the
filters was 14.3 mg/1 with the corresponding effluent
BOD ranging from 1.3 to 2.8 mg/1.
In general, the filtered effluent BOD5 increased
with an increase in the hydraulic loading rate.
However, such increases are relatively slight and may
not be statistically significant.
The chemical oxygen demand (COD) of the
filtered effluent for each hydraulic loading rate is
reported in Table 3, and shown graphically in Figure
11. The average influent COD was 69.7 mg/1, while
the effluent COD values changed from 27.5 mg/1 (0.6
mgad) to 49.7 mg/1 (1.2 mgad).
In general, the pattern of COD removal was
similar to that for BOD5 removal. The effluent COD
appeared to increase slightly with increases in the
hydraulic loading rate.
Ammonia, nitrite, nitrate
The ammonia, nitrite, and nitrate concentra-
tions in the filtered effluent for each hydraulic
SUSPENDED SOLIDS VS.TIME LOADING RATE *0.4 mgad
0 JULY 29, 1974
A JULY 30, 1974
VSS < 1.0 mg/1
INFLUE_NT_
INFLUENT
75 100 125 150
TIME (mln)
175 200 225
Figure 7. Filtered effluent suspended solids concentration with time.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents
81
loading rate is reported in Table 3 and shown
graphically in Figures 12, 13, and 14. The influent
ammonia-nitrogen concentration averaged 2.469 mg/1
NH,-N while effluent ammonia-nitrogen concentra-
tions were all less than 0.541 mg/lNH3-N. Figure 12
indicates that the effluent ammonia-nitrogen con-
centration increases with an increase in hydraulic
loading rate. The influent ammonia-nitrogen is
probably converted to nitrate-nitrogen by nitrifica-
tion (see Figure 14) rather than being physically
removed. Thus, the increase in effluent ammonia-
nitrogen with hydraulic loading rate indicates that
less nitrification occurs at the higher loading rates.
The decrease in the nitrification process at the
higher hydraulic loading rate is evident in the
nitrite-nitrogen and nitrate-nitrogen concentration of
the filtered effluents. Figure 13 indicates that
effluent nitrite-nitrogen almost doubled between the
0.2 mgad and the 1.2 mgad hydraulic loading rates.
Figure 14 indicates a definite decline in effluent
nitrate-nitrogen concentration
hydraulic loading rate.
with increased
The apparent decrease in nitrification with
increasing hydraulic loading rates suggests that the
bacterial population in the higher loaded filters is less
efficient. This could be a result of organic overloading
which may cause anaerobic conditions to exist within
a portion of the sand filter bed and restrict the
nitrification process.
Phosphorus
The values for both influent and effluent total
phosphorus and orthophosphorus are reported in
Table 3. Although effluent phosphorus concentra-
tions are less than influent values, previous experi-
ments (Marshall and Middlebrooks, 1974) have in-
dicated that this is due to ion exchange within the
filter sand bed and that once the ion exchange sites
become saturated, phosphorus removal does not
CO
o
CO
o
tu
o
z
UJ
Q.
CO
o
CO
20
Q 15
10
INFLUENT
0.2 0.4 0.6 0.8 1.0 1.2
LOADING RATE IN mgad
Figure 8. Suspended solids in filtered effluent.
-------
82 Reynolds, Harris, Hill, Filip, Middlebrooks
IO.W
16.0
>.
z
to 12-0
Q
8 10.0
£
i 8.0
UJ
Q.
§6.0
UJ
C 4.0
5
_j
5 2.0
16.5
'**
t
f*
••f
.•>-'
.:!
rn
Bl r«3 I'M E^l P^l I3«l
H- TJ T» T» TJ TJ T>
1 1 1 1 1 1 1
J C\J * - -
Figure 9. Filter volatile suspended solids performance.
occur. Thus, further operational experience is re-
quired before any definite conclusion on filter
phosphorus removal performance can be justified.
Filter performance evaluation
A crude attempt to select the optimum
hydraulic loading rate based on the information
presented in this report is presented in Table 6. Seven
parameters were selected to indicate overall filter
performance. Each hydraulic loading rate was rated
with a number between one and six. A rating of one
indicates superior performance in a particular para-
meter while a rating of six indicates poor perfor-
mance. In areas where two filters had equal perfor-
mance the rank order was averaged.
The average rating for each filter was then
determined without giving particular weight to any
one parameter. The results indicated that the filters
with a hydraulic loading rate of 0.4 mgad or 0.6 mgad
were superior to the other hydraulic loading rates.
However, such a selection must be viewed with
extreme caution because of the limited data available
for analysis and the selection process employed. The
result could be substantially different if the selection
parameters were weighted according to importance
based on design, construction, and operational
criteria.
0»
E
O
00
10.0
8.0
6.0
4.0
2.0
INFLUENT
'0 0.2 0.4 0.6 0.8 1.0
LOADING RATE IN mgad.
1.2 1.4
Figure 10. BOD5 in filtered effluent.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents 83
120
Q
O
O
IOO
80
60
40
20
INFLUENT
Q2 0.4 0.6 0.8 1.0
LOADING RATE IN mgad
Figure 11. COD in filtered effluent.
1.2 1.4
o»
E
2.5
2.0
1.5
- 1.0
10
0.5
INFLUENT
0.2 0.4 0.6 0.8 1.0 1.2
LOADING RATE IN mgad
1.4
Figure 12. Ammonia nitrogen in filtered effluent.
-------
84 Reynolds, Harris, Hill, Filip, Middlebrooks
i
CVJ
O
0.25
0.20
0.15
0.10
0.05
INFLUENT
V0 0.2 0.4 0.6 0.8 1.0 1.2
LOADING RATE IN mgad
Figure 13. Nitrite nitrogen in filtered effluent.
5.0
4.0
3.0
1.4
i
to
O
2.0
1.0
0 (X2 0.4 0.6 0.8 1.0 1.2
LOADING RATE IN mgad
1.4
Figure 14. Nitrate nitrogen in filtered effluent.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents
85
Table 6. Overall filter performance evaluation.
Loading
Rate in
mgad
0.2
0.4
0.6
0.8
1.0
1.2
BOD5
3
1
2
5
4
6
COD
5
2
1
4
3
6
SS
4
1
3
6
5
2
vss
3
4.5
6
1
4.5
2
NO3-N
3
2
1
4
5
6
Algal
Mass
Removal
2
3
1
4
5
6
Hydraulic
Loading
Rate
6
5
4
3
2
1
Average
Ranking
3.71
2.64
2.57
3.85
4.07
4.14
Comparison With Previous Results
The full-scale filters have basically duplicated
the performance of the laboratory and pilot scale
units (Marshall and Middlebrooks, 1974). In all cases
when the BOD, SS, VSS, and nutrient concentrations
applied to the systems were approximately equal,
removals obtained at various hydraulic loading rates
are practically indistinguishable between the labora-
tory, pilot, and full-scale filters.
Fines were washed from the full-scale filter
media for a considerable period of time as was the
case with both the laboratory and pilot scale units.
This accounted for the majority of the solids in the
effluents from the filter units. Volatile suspended
solids averaged less than 1 mg/1 in the effluent from
the full-scale filters at all six loading rates employed;
whereas, in the laboratory and pilot units the effluent
VSS concentrations frequently exceeded 4 mg/1.
Whether this difference was caused by the
characteristics of the genera of algae being removed
or is attributable to variations in laboratory technique
cannot be determined. However, there were sig-
nificant differences in the genera of algae present.
During both the laboratory and pilot studies,
Chlamydomonas sp. were the predominant genera in
the lagoon effluent with only an occasional diatom
(5 percent) or Anabaena sp. (5-20 percent). At no
time were there less than 75 percent Chlamydomonas
sp. in the effluents applied to the filters. The
full-scale filters received a lagoon effluent containing
mostly a blue-green coccoid alga, tentatively
identified as Aphanocapsa sp. and Chlamydomonas
sp. were present in only small amounts (see Table 4).
Because the performance of the full-scale filters was
in most cases superior to the laboratory and pilot
units, it appears that algal genera have little impact on
the intermittent sand filter. The Aphanocapsa sp. are
much smaller than the Chlamydomonas sp. and do
not agglomerate; therefore, a large percentage of the
Aphanocapsa sp. would be expected to penetrate and
pass the filters. However, this did not occur with the
.170 mm effective size sands used in the full-scale
filters.
BOD, removals were essentially the same for all
three size systems, and an effluent containing less
than 5 mg/1 was obtained at all hydraulic loading
rates. The mean influent BOD5 concentrations
applied to the laboratory and pilot filters were
approximately 50 percent greater (13 mg/1 versus 8
mg/1) than that applied to the large units, but
approximately equal quality effluents were produced.
Apparently, as in other biological systems, there are
certain compounds which are difficult to biodegrade
during the short residence time in the filters. Con-
sequently, a minimum effluent BOD5 concentration
of approximately 2 mg/1 can be obtained with the
intermittent sand filter.
The pH values of all filter effluents were
approximately 8.0, but ranged from 7.9 to 8.9. The
value was influenced greatly by the characteristics of
the lagoon effluents.
Effluent D.O. measurements were not perfor-
med on the laboratory and pilot units. In the
full-scale unit the D.O. concentration of the effluents
were directly related to the loading rates. Up to a
loading rate of 0.8 mgad the effluent D.O. con-
centration was greater than 5.5 mg/1 as required in
the Utah Class "C" standard. Above 0.8 mgad the
effluent D.O. concentration dropped below 5.0 mg/1
in several samples.
Because of the differences in applied algal
concentration, a direct comparison of the length of
run obtained with the various size units is difficult.
However, at common hydraulic loading rates and
approximately equal algal concentrations, the units
operated about equal periods of time before plugging.
Approximately one month of continuous operation
at the peak algae production in the lagoons can be
expected with a filter containing sand with an
effective size of 0.17 mm. The larger surface areas
exposed to the sunlight in the large filters introduced
-------
86 Reynolds, Harris, Hill, Fitip, Middlebrooks
a variable not encountered in the laboratory and
encountered to a more limited extent in the shaded
pilot units. A significant increase in algal concentra-
tions due to growth after the lagoon effluent was
applied to the filters probably accounted for the
slightly shorter filter runs obtained in the full-scale
units. The same asymptotic relationship developed in
all size units when the days of operation were plotted
versus the hydraulic loading rate. A loading rate of
approximately 0.5 mgad continues to appear to be
the optimum based upon solids and BOD, removals
and period of operation between cleanings.
The large units have so far confirmed the
conclusions based upon the laboratory and pilot scale
system. Intermittent sand filtration treating
secondary lagoon effluent is capable of consistently
producing an effluent with VSS and BODj concentra-
tions of less than 5 mg/1, and provides operational
simplicity and economy.
Series Intermittent Sand Filter Performance
A study is currently underway at the Utah
Water Research Laboratory, Utah State University, to
determine the feasibility of operating intermittent
sand filters with different effective size sands in
series. At present three pilot scale (16 sq ft surface
area each) series filter operations are under study.
Each filter operation consists of three filters in series
with the initial filter having an effective size sand of
0.72 mm, the intermediate filter sand effective size is
0.4 mm, and the final polishing filter has an effective
size sand of 0.17 mm (see Figure 15). Hydraulic
loading rates for the three systems are 0.5 mgad, 1.0
mgad, and 1.5 mgad. Preliminary results indicate that
0.5 mgad
1.0 mgad
0.72mm
1.5 mgad
0.72mm
0.72mm
0.40mm
0.40mm
0.40mm
0.17mm
0.17mm
0.17mm
Figure 15. Series intermittent sand filtration operation.
-------
Intermittent Sand Filtration to Upgrade Lagoon Effluents 87
a high quality effluent is produced and that the
length of filter run is substantially increased.
Summary and Conclusions
Wastewater lagoons provide simple, economical,
and low maintenance waste treatment for many small
communities. However, the degree of treatment
possible with lagoons may be inadequate to meet
future discharge standards. Therefore, a definite need
exists to develop a system which can simply and
economically upgrade lagoon effluents to a level
which satisfies future discharge requirements.
A full-scale experimental intermittent sand fil-
tration system has been constructed at the Logan
Municipal Sewage Lagoons by the Utah Water Re-
search Laboratory, Utah State University. The objec-
tive of the project is to evaluate the performance of
intermittent sand filters in upgrading the quality of
wastewater lagoon effluent. Data have been collected
and analyzed from July 12, 1974, to August 22,
1974, for hydraulic loading rates ranging from 0.2
mgad to 1.2 mgad.
Based on the information presented in this
article and previous studies (Marshall and Middle-
brooks, 1974) the following conclusions can be made.
1. The algal genera present in the lagoon
effluent have little impact on perfor-
mance of the intermittent sand filters.
2. Length of filter run is directly related to
influent algal concentration and hydraulic
loading rate.
3. The full-scale filters had a slightly shorter
length of filter run than did previous
laboratory and pilot scale filters.
4. The length of filter run observed in the
full-scale filters was substantially affected
by algal growth in the liquid above the
filter.
5. The length of filter run varied from 14
days with a hydraulic loading rate of 1.2
mgad to 42 days with a hydraulic loading
rate of 0.4 mgad.
6. The filter with a hydraulic loading rate of
0.6 mgad removed over twice as much
total suspended matter as did the filter
with a hydraulic loading rate of 1.2 mgad.
7. It is necessary to allow a period of time
for the filters to "wash" out fines intro-
duced during construction, before a low
effluent suspended solids concentration
can be achieved.
8. With an average influent suspended solids
concentration of 26.1 mg/1, all filters
produced an effluent suspended solids
concentration of less than 7.2 mg/1.
9. Effluent suspended solids concentration
increased slightly with an increase in the
hydraulic loading rate.
10. With an average influent volatile
suspended solids concentration of 16.9
mg/1, all filters produced an effluent with
less than 1.5 mg/1 of volatile suspended
solids.
11. The filtered effluent volatile suspended
solids concentration is independent of
hydraulic loading rate.
12. The intermittent sand filter can produce a
consistent effluent BOD5 of less than 5.0
mg/1.
13. Filtered effluent BOD5 increases slightly
with an increase in the hydraulic loading
rate.
14. Filtered effluent COD increases slightly
with an increase in the hydraulic loading
rate.
15. Influent ammonia-nitrogen concen-
trations were reduced from 2.469 mg/1
NH3-N to less than 0.541 mg/1 NH3-N by
all hydraulic loading rates.
16. The full-scale intermittent sand filters
essentially confirm the previous labora-
tory and pilot scale studies.
17. Experiments are currently being con-
ducted to evaluate the performance of
series intermittent sand filter operations.
Acknowledgments
The work upon which this article is based was
performed pursuant to Contract No. 68-03-0281 with
the Environmental Protection Agency.
Dr. Ronald F. Lewis has been the Project
Officer supervising this contract for the Environ-
mental Protection Agency.
References
American Society of Civil Engineers and Federation of
Sewage and Industrial Wastes Association. 1959. A
Joint Conference on Sewage Treatment Plant Design.
New York.
APHA, AWWA, WPCF. 1971. Standard methods for the
examination of water and wastewater. 13th Ed.,
American Public Health Association, Inc., New York,
New Yoik.
Calaway, W. T., W. R. Carroll, and S. K. Long. 1952.
Heterotrophic bacteria encountered in intermittent
sand filtration of sewage. Sewage and Industrial Wastes
Journal 24(5):642-653.
EPA. 1971. Methods for chemical analysis of water and
wastes. Environmental Protection Agency.
-------
88
Reynolds, Harris, Hill, Filip, Middlebrooks
Furtnan, Thomas De Saussure, Wilson T. Calaway, and
George R. Grantham. 1949. Intermittent sand filters-
multiple loadings. Sewage and Industrial Wastes Journal
27(3):261-276.
Grantham, G. R., D. L. Emerson, and A. K. Henry. 1949.
Intermittent sand filter studies. Sewage and Industrial
Wastes Journal 21(6):1002-1015.
Marshall, G. R., and E. Joe Middlebrooks. 1974. Intermittent
sand filtration to upgrade existing wastewater treat-
ment facilities. PRJEW115-2, Utah Water Research
Laboratory, College of Engineering, Utah State Univer-
sity, Logan, Utah.
Solorzano, L. 1969. Determination of ammonia in natural
waters by the phenolhypochlorite method. Limnology
and Oceanography 14(5): 799-801.
Strickland, J. D. H., and T. R. Parsons. 1968. A practical
handbook of seawater analysis. Bulletin No. 167,
Fisheries Research Board of Canada, Ottawa.
-------
PERFORMANCE OF RAW WASTE STABILIZATION LAGOONS IN MICHIGAN
WITH LONG PERIOD STORAGE BEFORE DISCHARGE
D. M. Pierce
1
Background
In recent years the prevalance and popularity of
the waste stabilization lagoon have grown in many
sections of the country. Many additional projects of
this kind are now under construction or in the
planning stage, largely in very small communities.
Some, however, are proposed for flows of up to one
million gallons per day. Although several thousand
municipal projects of this kind are in operation
today, and generally considered to be performing
quite satisfactorily, very little factual information has
been assembled on their performance. So today, with
the adoption of regulations calling for a minimum of
secondary treatment as specifically defined and
future requirements for "best practicable treatment"
there is an urgent need to assess the capability of this
method of treatment when opeated under a variety of
conditions.
Information collected at municipally-owned
and operated lagoons in Michigan during the past 5
years indicates that systems with relatively low
organic loadings, long storage periods, and twice-
yearly discharge hold promise of meeting the require-
ments for secondary treatment. The special EPA
work group on waste stabilization lagoons has ex-
pressed interest in exploring the efficacy of this
method and how it can be managed most effectively
to achieve maximum performance dependably.
Accordingly a study was undertaken for this purpose.
The person conducting this study is intimately
familiar with the Michigan program, having been
responsible for state regulatory control of design and
operation of municipal wastewater facilities for many
years until last July. This relationship assured the full
cooperation and support of both regulatory agency
personnel and municipal officials and employees in
assembling and interpreting the essential information.
Many conferences were held with division engineers.
Visits were made to operating faculties in company
with operation personnel. Many people performing
1D. M. Pierce is special consultant for the U.S.
Environmental Protection Agency.
the analyses on the lagoon effluent samples provided
valuable and timely information, particularly on
samples recently analyzed.
Faculties Studied
To obtain maximum available pertinent infor-
mation it was decided to assemble information on all
municipal raw waste stabilization lagoons discharging
effluents during the past 2 years. Presently there are
about 125 municipal lagoon systems in the state.
Many have not had their first discharge by reason of
the recency of their completion, or because of soil
conditions favoring high on-site percolation rates. A
few of the facilities have some aeration facilities.
Others were designed for percolation into the ground.
Neither of these were included in the study.
It was found that 49 of the systems are
representative of the selected pattern of long storage
and twice-annual discharge. Each of these have
sufficient operational data to permit a meaningful
evaluation of performance.
Although there are quite a range in design
features and operational methods, ah1 conform to a
general pattern adopted by the state regulatory
agency several years ago as part of the overall
pollution control plan related to water quality stan-
dards.
Essential Features of Michigan
Lagoon Program
The following information is provided to
acquaint the reader with pertinent background on
concepts relating to loadings, construction features
and management methods used by operating per-
sonnel and the relationship between the operator and
the state regulatory agency. This should be helpful in
the interpretation and understanding of the data
collected and analyzed in this study.
Design features
Generally, the principles of design specified in
Chapter 90 of the Recommended Standards for
Sewage Works adopted by the Great Lakes-Upper
89
-------
90
Pierce
Mississippi Board of State Sanitary Engineers (Ten
States' Standards) have been incorporated in these
projects. In all cases the design loading has been
approximately 100 persons (or PE) and 20 Ibs BOD5
per acre. Inlet, outlet, and interconnecting piping
usually permits control of raw sewage into any cell
and the discharge of treated wastewaters from any
cell. Valving permits a variety of flow patterns with
capability to isolate any cell or combination of cells.
Sealing of the bottom and side slopes is provided in
all of these systems to permit control of water depths
within practical limits. Clay is most commonly used
although bentonite has been mixed with resident soils
at a few locations.
Apportionment of surface area and capacity
among the cells in the system varies considerably.
Maximum operating water depth usually is about 6
feet plus or minus 1 foot. (See Table 1 for capacity
and discharge data.) Quite commonly cells are equal
in area and volume. Some have equal area in each cell,
but different maximum operating water depths.
Usually the shape, area, and depths depend to some
extent on topography and shape of available pro-
perty, relative elevation of inlet sewer and point of
lagoon discharge, depth to rock or water table, cost of
earth moving, and related considerations.
Great care is taken in the earth work during
construction to provide good mixing of the sealing'
materials with native soils, a level bottom free of
debris or organic material and a well aligned shore-
line. Slopes are seeded or sodded to reduce erosion
and to permit grass mowing and weed control.
Discharge control facilities are designed to
permit selection of any desired elevation for dis-
charge, ranging from highest water elevation (auto-
matic overflow level) to within a foot or so of the
bottom.
All of these systems were designed for semi-
annual discharge, with retention of total flow from
the sewer system from late November until about
April 15 and from about May 15 to October 15. It is
expected that the contents will be discharged during a
period of 2 to 4 weeks depending on the quantity
stored; rates of percolation, precipitation and evapor-
ation; hydraulic capacity limitations of the piping
system; and the quality of the effluent in relation to
conditions in the receiving water body. This leaves
some 150-170 days for summer and winter storage
without discharge. Since in Michigan annual precipi-
tation and evaporation are about equal, the volume
accumulated in 160 days between discharge periods
would increase water depth by about 5 feet, assuming
an average flow of 100 gallons per capita per day and
no percolation. If the rate of percolation is 1/8 inch
per day, the 5-foot increase in water depth would be
reduced by 20 inches leaving 3 to 3H feet of depth to
be discharged. Experience has shown that actual
accumulations may range from 1 foot to as much as 8
feet in the theoretical 160-day period. In some
instances combinations of low per capita flow rates,
high percolation, high evaporation and low precipi-
tation rates result in such a low increase in water
volume that no discharge is needed or desirable in one
of the normal semi-annual discharge periods. There
are several situations of this kind, particularly in the
early years of operation, where no discharge is made
for up to two years. These are not included in this
study. In other circumstances where per capita flow is
high, usually by reason of high inflow-infiltration
rates, minimal percolation and high precipitation-
evaporation ratios, the rate of accretion in the
lagoons is so high that discharge periods in either or
both spring and fall must be extended over a period
of 30 days or more after accumulation to the
maximum safe water elevation.
Operation and maintenance practices
The state regulatory agency requires each
municipality to delegate full responsibility for lagoon
operation and maintenance to one person on its
public works staff. Wastewater Division personnel
work with this person and other members of the
work force in a continuing consultation and sur-
veillance program, including both assembled and
on-the-job training and advice. A manual on opera-
tion and maintenance principles is furnished each
local operating agency for general guidance in addi-
tion to the manual which EPA now requires for each
funded project.
Regular operation routine involves daily visita-
tion and maintenance of lift stations. Usually the
lagoon site is visited each day of the 5-day working
schedule to observe conditions and perform essential
operations. All lagoon properties are fenced and have
locked gates. On each visit the operator drives his
pickup truck on the roadway atop the dykes making
a complete tour of the lagoons to observe their
condition. He looks for signs of burrowing rodents,
surface scum, sludge buildup near inlets, emergent
weeds, and evidence of erosion. Action is taken as
soon as possible to correct any adverse conditions.
Grass and weeds on dyke slopes and tops are mowed
when needed to assure a dense growth for erosion
control. Brush and weeds at the shoreline are re-
moved or otherwise controlled to prevent spreading
which would interfere with natural waste treatment
processes. Attention is given to management of flow
into and between cells. In some systems normal flow
patterns consist of the raw waste entering Cell No. 1
and flowing to Cell No. 2 through the connecting
pipe located near the bottom. Flow from Cell No. 2
to Cell No. 3 is similar to this. In other systems
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 91
differences in elevation require manual regulation of
flow between the cells by the operation of valves.
Prom time to time conditions require re-routing of
flow for water depth adjustment, temporary resting
of a cell, repair work, etc. Stop gates, valves, and
control structures are examined occasionally and
maintained or repaired if needed.
Records and reports
Observations are recorded routinely on stan-
dard monthly operation reports furnished by the
state regulatory agency, Forms D-4.9 and D-4.9a.
Sewage flow quantities (where measured), power
consumption, and weather data are recorded daily.
Lagoon liquid depth, dissolved oxygen, and ice
conditions are recorded at least one day per week
during the storage season and daily during discharge.
Flow patterns among the lagoons and effluent dis-
charge are to be recorded regularly on Form D-4.9a.
Discharge control program
Discharge of effluents follows a consistent
pattern for all lagoons. The following steps are
usually taken:
1. Isolate the lagoon to be discharged, usually
the final one in the series, by valving-off the inlet line
from the preceding lagoon.
2. Arrange with a nearby community to
analyze samples for chemical analysis including BOD,
suspended solids, volatile suspended solids, pH, and
frequently for total phosphorus.
3. Plan work so as to spend full time on
control of the discharge throughout the period.
4. Sample contents of lagoon to be discharged
for dissolved oxygen, noting turbidity, color and any
unusual conditions.
5. Note conditions in the stream to receive the
effluent.
6. Notify Basin Engineer of Wastewater Divi-
sion of the state regulatory agency of results of these
observations and plans for discharge and obtain his
approval.
7. If discharge is approved, proceed as follows:
Commence discharge and continue so long as weather
is favorable, dissolved oxygen is near or above
saturation values and turbidity is not excessive
following the prearranged discharge flow pattern
among the lagoons. Usually this consists of drawing
down the last lagoon in the series, or last two if there
are three or more, to about 18-24 inches after
isolation, interrupting the discharge for a week or
more to divert raw waste to the last lagoon (or to No.
2 if there are three or more) and resting the No. 1
lagoon before its discharge. When this lagoon is drawn
down to about 24 inches or so the usual series flow
pattern is resumed.
During discharge to the receiving waters sam-
ples are taken at least three times each day near the
discharge pipe for immediate dissolved oxygen
analysis. Composite samples of the lagoon effluent
are collected, usually 5 days per week, at points
designated by the Basin Engineer (see 6 above) for
chemical analyses. Each such sample is composed of
at least three equal volume portions collected morn-
ing, noon, and late afternoon. Samples are refrig-
erated during collection and delivered within 24
hours (usually same day) to the laboratory con-
ducting the analyses. The analyst must have demon-
strated capability to perform the analysis. All work is
performed in accordance with Standard Methods on
unfiltered samples.
At least one grab sample per day, 5 days per
week, is collected for analysis of fecal and total
coliforms in sterilized bottles furnished by the State
Department of Public Health. The standard bacteri-
ological analysis form F216a is used to record
pertinent information and is mailed with the bottle to
the department for analysis.
The person performing the chemical analyses
furnishes the operator and the regulatory agency a
copy of the test results when all analyses for the
seasonal discharge have been completed, using Form
R4613. Coli test results are recorded on the Standard
Bacti form and furnished to the Wastewater Division
and the operator.
The Study and What It Reveals
The prime objective of this study is to deter-
mine whether and under what conditions the secon-
dary treatment requirements can be met by raw waste
stabilization lagoons designed and operated in the
manner outlined in the foregoing discussion.
Attention was given to factors which might affect the
level of performance, as reflected in effluent quality.
Factors considered were effect of differences in
population loadings per acre or unit volume; number
of cells; length of discharge period; comparison of
spring with fall discharges; effect of ice cover and low
temperatures without ice; relationship of BOD5 to
suspended solids under varying conditions; and trends
and levels of coliforms under varying conditions; and
relationship of total coli to fecal coli.
-------
92
Pierce
Study methods
The cooperation and assistance of the Munici-
pal Wastewater Division, Department of Natural
Resources, was solicited in providing access to all
pertinent records, reports, and design data. This was
provided in full measure in many most helpful ways.
Discussions with division staff members assisted
greatly in identifying the lagoons which have dis-
charged effluents during the past 2 years and in
obtaining desired information on design features,
population loadings, presence of industrial wastes,
identification of operating personnel and any unusual
problems known to exist which might affect per-
formance. All monthly operation reports and dis-
charge reports were made available for review. Many
were discussed with the responsible basin engineer for
clarification and analysis.
Many of the operators were contacted directly,
by telephone or visitation, to obtain additional
information or to discuss reported conditions. In
several instances where chemical data on the effluent
discharges could not be found, the information was
secured promptly on request to the person per-
forming the analyses.
Data reviewed and recorded
It was determined that 49 municipal lagoons
met the selection criteria. All available data on
construction features, loadings and operating reports
were reviewed. These consisted of (1) monthly
operation reports for each lagoon system for the
years 1972 and 1973 and (2) discharge data for the 2
years. These data are recorded on Table 1.
Loadings
Loadings shown in Table 1 for each lagoon
system are expressed in terms of connected popula-
tion for the lagoon capacities listed. Unfortunately
there is insufficient flow data or raw sewage sampling
for most lagoons to be of much value. It may be
noted that most loadings are reasonably close to the
design value of 100 persons per acre, although several
are significantly lower than this and a few are well
above. Discussion with basin engineers revealed that
no industrial wastes are tributary to any of the
systems either in significant volume or characteristics.
Lagoon capacity
Of the 49 systems studied, 27 have 2 cells, 19
have 3 cells, 2 have 4 and 1 has 5. The number of
cells has no relationship to the total area or volume.
Acreage apportionment between cells is frequently
divided equally, although neither this ratio nor the
relative depths of the cells follow any consistent
pattern as may be noted from Table 1. Quite
commonly maximum operating water depths range
from 60 to 84 inches with 72 inches found most
frequently.
Discharge patterns and periods
The most common pattern of discharge is to
release the stored contents from the last cell in the
series following a period of several days, usually
about a week, with no inflow from preceding cells
and to reverse the process after this discharge is
completed. At some locations no isolation is provided
and inflow from Cell No. 1 to Cell No. 2 (or to Cells
2 and 3) continues during the total drawdown period.
Many communities do not record the information on
Form D-4.9a in a sufficiently clear and complete
fashion to show just what flow pattern is used and
how it is changed during the period of discharge. This
information was not required by the department until
a year or so ago. All available information is recorded
in Table 1, as explained in its attached legend.
Whenever possible the spring discharge is de-
layed until after the ice on the lagoon surface has
completely melted. Some locations have found it
necessary to discharge small quantities during the
early spring ice cover when water levels reach
elevations which would either produce automatic
overflows or endanger the integrity of the dykes.
From the column entitled No. of Days Since Ice-Out
indicates that ice remained in 1972 on most lagoons
until about April 15, but was gone by March 15 in
1973. Most systems are predicated on ice free con-
ditions by April 1.
Periods of discharge shown.under that title in
Table 1 indicate a substantial variation in calendar
period and number of days. Some of the periods
shown include the intermediate isolation time be-
tween discharges from Cell No. 2 (or 2,3,4) and Cell
No. 1; others clearly separate the two periods. The
total length of discharge periods for the 186 dis-
charges recorded in Table 1 are as follows:
No. Days Discharged
0-5
6-10
11-15
16-20
21-25
26-30
31 or more
No. Discharge Periods
15
69
46
24
11
8
13
-------
Month
.19
Exhibit I
OPERATION REPORT OF WASTE STABILIZATION LAGOONS
, Michigan
Operator
MOPH
D- 4.9
DATE
1
2
3
4
5
6
7
8
9
10
11
12
13
U
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
TOTAL
WEATHER
TEMP. -F
Max.
^~>p^
Win.
§^%^ir
a
Ty»e
b
Wind
Precip.
inches
Flaw
MGD
Power
KWH
LIQUID DEPTH-Ft.
CELL
1
igpf^
2
3
T'
D. 0. Mg/l
TIME
1
CELL
*
3
%
ICE
COVER
ODORS
R L MARKS
a. Weather Type - C- Clear CL - Cloudy R- Rain
b. Wind - Indicate strength and direction — S- Strong
c. Odors - S- Slight M- Moderate 0- Offentive
W- Windy CA- Calm
M- Med. W- Weak
- Complaints
-------
D-4.9 - INSTRUCTIONS
Weother - Report Doily
Temp. - Data should be from a reliable source in community. Data must be from a maximum-minimum thermometer.
Precip. (inches) - Data should be from a reliable source in the community, either at the plant or elsewhere. Do not use general area data. For
information regarding official weather stations, write State Climatologist, Room 202, Manly Miles Building, 1405 South Harrison, East Lansing,
Michigan 48823. If no reliable source is available install a precipitation gage as recommended by the State Climatologist.
Flow (MGO) - Report Dolly
The raw sewage flow should be reported in million gallons per day (MGD), for example: 70,000 gallons per day as 0.07 MGD.
375,000 gallons per day as 0.38 MGD.
3,750,000 gallons per day as 3.75 MGD.
Use no more than three figures.
Power — Report Doily
Report the power consumed for pumping at the major pump station in kilowatt hours (KWH).
Liquid Depth - Report ot Leost Weekly
The depth to the nearest one-half foot in each of the lagoon cells, for example: 2 foot 2 inches as 2 ft.
4 foot 7 inches as 4l/2 ft.
5 foot 10 inches as 6 ft.
Dissolved Oxygen
Report time when a dissolved oxygen sample is taken. The dissolved oxygen concentration should be reported at least once a week in each cell
during the period when the lagoon is not being discharged and once a day during discharge on the cell being discharged, recording
the minimum D.O. value of at least three samples taken during the day (morning, noon and evening).
Ice Cover — Report ot Least Weekly
Report the percentage of the lagoon system covered with ice. If measurements of ice and snow depths are taken report these results in remarks column.
Odors
Report odor condition as noted on form. If odors are not detectable indicate with dashed line in appropriate space. Discuss any unusual circumstances
concerning odors in remarks column.
Remarks
This space should be reserved for any observations and information not included in other parts of this form. Observations on algae concentrations (both
suspend*-^ and floating) color and turbidity in the lagoon along with comments on efforts to control rodents, insects and weeds should be reported. Prob-
lems with industrial waste, storm water or infiltration should also be noted. If additional space is necessary, please use Supplemental Remarks Sheet.
Flow Pottern
Indicate by brief sketches on Supplemental Remarks Sheet (MDPH - D-4.9a) the pattern (or route) of flow through the lagoon system.
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 95
Exhibit 2
WASTE STABILIZATION LAGOONS
SUPPLEMENTAL REMARKS SHEET
., Michigan
Month 19 Operator .
H.OW I'ATThRN (Sketch flow pattern in space provided below, indicating dates during month. If more than
one pattern was used make an additional sketch for each period.)
From _ __ _ To
(Dale)
From _________ To
(Data)
From To
(Dmtt) (Dmle)
REMARKS
-------
96 Pierce
D-4.9a
INSTRUCTIONS
Row PiUtcrn
Indicate by brief sketches on Supplemental Remarks Sheet (MDPH- 4.9a) the pattern (or route) of
flow through the lagoon system.
Examples:
From
Raw
October 1, 1968
(Dale)
To
October 4, 1968
(Date)
From
October 5. 1968
(Date)
To
October 13. 1968
(Date)
Raw
Discharge
From
October 14, 1968
(Date)
Raw
To
October 22, 1968
(Date)
From
October 23, 1968
(Date)
Raw
To
October 31. 1968
(Dale)
Discharge
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 97
Exhibit 3
Sample
No.
BACTKRim.Or.lCAL ANALYSIS
SEWAGE, INDUSTRIAL WASTES AND SURFACE WATERS
MICHIGAN DEPARTMENT OF PUBLIC HEALTH
BUREAU OF LABORATORIES
Lansing Houghton Powers Grand Rapids
F21h., 10M 768
Received
Note: Use pencil - Answer all questions and underline words thai apply.
1. Source Sta. No. County _
2. Location
3. Date
4. Water temperature.
, Time.
.Depth
Pt. in cross section
. Collected by ...
- Width Flow _.
5. Turbidity: turbid, slightly turbid, clear, evidence of sewage, septic.
6. Color _ Odor: offensive, strong, light, none.
7. Bottom: sand, gravel, silt, clay, rocky, sludge.
8. Vegetation: weeds, algae, fungi. Amount: abundant, sparse, none.
9. Fish life: yes, no. Species .
10. Weather: clear, partly cloudy, cloudy, rain.
11. Wind: strong, moderate, calm. Direction
12. Nearest source of pollution
13. Distance to source of pollution
14. Use of frontage and/or water: water supply, public park, bathing, fishing,
residential, farming, pasture, undeveloped, or
15. Report results to ;
LABORATORY RESULTS
MEMBRANE FILTER
METHOD
All results reported
as counts per 100 ml.
Coliforms
DIFFERENTIAL TESTS
Fecal Coliforms
Fecal Streptococcal
Group
Examiner
Address.
Reported-Copies
I
(Ij
Chief, Bureau ol Lcbo, Horn-:.
Effluent quality—BOD and suspended solids
Records were reviewed and recorded for
analyses of BOD and suspended solids on 1475
samples from the 49 lagoon systems. Each of these
samples was a daily composite collected by the
operator. This information is recorded under Dis-
charge Data-Chemical in Table 1. Ranges of Values
and arithmetic averages are shown for each seasonal
discharge period.
The BOD and suspended solids data were
analyzed statistically in terms of probability of
occurrence. All values were arranged in order of
magnitude and plotted on normal probability paper
with concentration (mg/1) plotted against probability
the value would not be exceeded under similar
conditions. Separate plots were made for 2-cell and 3
or more cell systems. These plots (see Figures 1,2,
and 3) reveal the following quality levels.
% Probability of Occurrence
Mean for Period
Most Probable
90% Probability
2 Cells
BOD SS
17 30
27 46
3 or
More Cells
BOD SS
14 27
27 47
The distribution of values is reasonably con-
sistent with normal distribution showing a high
degree of uniformity for BOD and a reasonably good
distribution for suspended solids. No statistically
significant difference can be seen between the 2-cell
and 3 or more cell systems for the loadings experi-
enced.
The data do not reveal any detectable differ-
ence in levels of BOD or suspended solids between
spring and fall discharges, including those from under
the ice. Nor is any variation noted with variations in
number of days discharged. Further, study of re-
corded water levels during discharge failed to show
any definite trend related to rate of drawdown
(inches per day) or from initial drawdown to low
discharge level. The exception to this is when the
water level is reduced below about 18 inches or when
the point of drawoff is at or below that level. In these
cases BOD and suspended solids concentration in-
crease sharply.
Effluent quality—coliforms
Analyses for total coli and fecal coli performed
by the bacteriological laboratories of the Michigan
Department of Public Health were reported on
-------
98
Pierce
standard forms F216a. A total of 1523 such forms
were reviewed and the fecal coli per 100 mis recorded
in Table 1. This represents 1523 individual samples
analyzed, one for each day the samples were collected
by the operators.
The fecal coli data were reviewed for con-
formity with the secondary treatment requirements
of 200 for 30 consecutive samples and 400 for 7
consecutive samples. Where these standards are met,
this is indicated by an X. When the geometric mean
exceeded these levels the mean is recorded.
These data clearly indicate that the 200 and
400 levels were met consistently except: (1) When
the ponds were ice covered or a few days following
final thawing of ice, and (2) late in the fall at some
locations as water temperatures reach low levels in
the lagoons (Birch Run, Bridgman, and Plainfield
Township). This temperature dependency deserves
further study, but it is clear that low fecal coli levels
cannot be achieved dependably when ponds are
ice-covered or a few days afterward.
Although analyses for total coli have been
performed routinely on lagoon samples for several
years, the state regulatory agency did not require
fecal coli data until about 2 years ago. Facts on fecal
coli levels are just now emerging. There are still a few
locations today where only total coli data are
available as noted in Table 1.
An in-depth study of fecal coli data was made
to examine seasonal trends in coli levels, both total
and fecal. Typical facilities were selected and all
available data are recorded in Table 2. These data
reveal the dramatic decrease in fecal coli levels from
ice covered conditions to warmer weather conditions.
The lack of any consistent relationship between
total coli and fecal coli shown in Table 2 is typical of
what generally was found at other installations.
No relationship or indicated trend could be
found between fecal coli concentrations and levels of
BOD or solids in the effluent. There appeared to be
no difference in coli levels for 2 cells compared with
3 or more cell systems.
General Conclusions
Study of operational data and related infor-
mation from 49 lagoons for two years clearly
demonstrates that, with long period storage prior to
fall and spring release, lagoons can consistently
produce effluents meeting EPA requirements for
secondary treatment for BOD and fecal coli and
generally can meet the suspended solids requirement,
when loadings are in the 100 person per acre range.
No data were available to indicate the effect of higher
loadings or short retention periods. It is recognized
that performance at this level requires the application
of generally accepted principles of design and con-
struction and that a reasonable amount of attention
by well trained and interested public works oriented
operators is essential.
-------
STATE OF MICHIGAN
DEPARTMENT OF NATURAL RESOURCES
Exhibit 4
WASTE STABILIZATION LAGOON DISCHARGE REPORT
R 4613 4/74
19.
Michigan
Sup«rinttnd«nt's Signature
Plant No. Mo. V Sampling Point Cod*
*
MF
MPN
Facal
31616
31615
Tol»l
31S04
31505
o
A
1 2
PN
ff
O1
02
O3
04
05
06
07
08
09
10
11
12
13
14
IS
16
17
18
19
2O
21
22
23
24
26
27
28
29
30
TI-
ME
WA
FLOW
MGD
50050
BOD
14
mg/l'
00310
SS
19
mg/l
00530
VSS
24
mg/l
00535
TOTAL-P
29
mg/l
00665
NH3-N
34
mg/l
00610
pH
39
su
00400
F. COLI*
44
*/100ml
31616
31615
T. COLI*
49
*/ 100ml
315O4
315O5
'
ICE COVER
ON STREAM
54
\
01 355
,'•• -
REMARKS OR OTHER PARAMETERS
59
64
69
74 78
80
C
^
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
3
c
c
c
c
-
;
:
J
c
:
;
;
:
c
j
c
9
14
19
24
19
-------
100
Pierce
WASTE STABILIZATION LAGOON DISCHARGE REPORT INSTRUCTIONS
Discharge reports are to be submitted by the tenth of the calendar month following
a month during which a discharge occurred. They should be mailed to: Municipal
Wastewater Division, Department of Natural Resources, Stevens T. Mason Building,
Lansing, Michigan 48926.
Enter lagoon identification code number in the six spaces following the letters ID.
In the next four spaces enter the date with the first two spaces being the month
and the next two being the year. The last three spaces should contain the sampling
point code assigned to your lagoon for final effluent. For example, ID 740055 10 73 000
would be the code for Yale's October 1973 discharge data.
If the results of a test reveal no detectable amount of the substance, then report
that the amount is less than the least detectable amount. For example, if the least
detectable amount of an analysis is 0.1 mg/1 and the analysis indicates less than
that amount, then report it as L 0.1. A dash should never be used. A blank implies
that no analysis was made.
If the magnitude of the numbers for a particular parameter exceeds four digits, the
row marked SF should be used. A Scaling Factor (SF) of 2 above a column would mean
that the numbers reported in that column should be multiplied by 100 to equal the
actual value of that parameter. Other Scaling Factors are as follows:
Multiplier
Scaling Factor
10
1
fO(T
2
1000
3
10000
4
100000
5
Etc.
IMPORTANT:
In no instance shall any number be reported in more than four digits
plus a decimal point or five digits without a decimal point.
FLOW - Total daily discharge flow should be reported using three figures.
example, 451600 gallons per day should be reported as 0.452 MGD.
For
REMARKS OR OTHER PARAMETERS - This space is provided for notes to the basin engineer
or for the record.Other parameters may be reported in these columns by listing the
parameter abbreviation and units in the top two rows, the Parameter Number (PN) in
the third, and the Scaling Factor (SF), if any, in the fourth. Parameter Numbers
may be obtained from your basin engineer or selected from the abbreviated list on
the Additional Chemical Analyses Sheet (R4612).
TOTAL - Enter column totals 1n the row marked TL, where it is not blacked out.
MEAN - Enter the Arithmetic Mean (Average) for all parameters except Coliform.
The Geometric Mean should be reported for the Coliform data.
If the discharge is covered by an NPDES permit with a 7 day Average (or Daily
Maximum or Minimum) condition, then, for such parameters, report the required data
in the row marked WA for Weekly Average. The 7 Day Average should be computed
from what appears to be the worst seven consecutive days.
-------
Table 1. Capacity and discharge data, waste stabilization lagoons, Michigan, 1972-73.
CAPACITY AND DISCHARGE DATA - WASTE STABILIZATION LAGOONS - MICHIGAN 1972-73
COMMUNITY
Ashley
Belding
Birch Run
Breckeoridge
POPULATION
DESIGN CONN
600
8000
1200
1250
550
4000
1300
1800
LAGOON CAPACITY
in
u
u
2
4
2
2
CELL 1
< ^ 5 «
U U B. 3!
3.0
20.3
6.0
6.0
108
72
72
72
CELL 2
5? *-• a S
3.0
15. J
6.0
6.0
108
72
96
72
CELL 3
3^N H w
O A. ^
5j ^ § "
*15.0
72
FLOW PATTERN
Al
Bl
Bl
"AI
Bl
Al
w
Crt
5°
og
0
"10
0
0
55
30
30
DISCHARGE DATA - EFFLUENT QUALITY
PERIOD OF
DISCHARGE
DATES
FROM-TO
72-04-14
to 05-15
73-03-23
to 03-30
73-04-23
to 04-27
72-04-11
to 04-27
72-10-02
to 10-25
73-03-16
to 04-09
73-11-05
to 11-13
72-04-12
to 04-28
72-06-06
to 06-19
72-10-28
to 10-30
72-11-08
to 11-16
73-04-12
to 05-07
19-22
72-05-10
to 05-22
72-10-16
to 10-31
I
32
8
1
17
24
24
c
17
14
8
9
25
13
16
CHEMICAL
W t-
8
8
9
11
<
3
16
14
9
18
13
1C
BOD
(mg/1)
RANGE AVG
7-9
~ 9-15
2-15
1-2
1-11
" 3-10
15-28
10-40
12-20
21-32
19-38
14-59
6-26
8
11
5
1
7
6
18
23
15
24
27
37
21
Susp.
Sol.
(ng/1)
RANGE AVG
32-41
11-63
14-60
2-14
27-58
no data
24-68
8-62
10-31
36-140
12-52
10-80
36
24
30
9
35
41
26
16
35
50
26
43
FECAL COLI
«!
<
36
8
5
9
11
ch
ch
17
14
7
9
18
8
N(
RANGE
*C10-36000
i.10-320
<.10-20
*10-1300
*10
.orinated
.orinated
^10-5100
4. 10-4100
*. 10-350
4600-5500
.C10-750
20-1100
) data
EPA SID.
200 400
X
X
X
X
X
X
X
X
4900
X
X
X
X
X
X
X
775
X
X
5000
X
X
NOTES
*Exceeded
stds. before
ice out
*
Cells 3 6, 4
each 7.5
acres
Ice cover
until 4-15-S
2 Coli
samples ^210
No fecal
coli data
for other
periods. Total coli
tests.
s
>o
t
s-
-------
Table 1. Continued.
COMMUNITY
Breckenridge
Continued
Bridgman
Brooklyn
BIT owns town
Township
Wayne County
POPULATION
DESIGN CONN
1250
1250
1200
1050
1800
1308
1107
1360
LAGOON CAPACITY
VI
tl
CJ
%
2
3
J
2
CELL 1
5 tj B, Z
5e ^ w C
6.0
4.5
5.0
7.7
72
72
78
60
CELL 2
«jj *-\
IS
6.0
4.C
3.5
10.8
es
Sjg
Q~
72
72
72
60
CELL 3
x ,-,
S^ H W
u a, a
tf < [4 *H
-< ^- Q ^
4.0
3.5
72
72
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
61
Al
Bl
~~A1
A4
Al
A2
Al
Al
A4
A3
Al
1*1
n
5g
Q H
tj
30
0
15
30
40
25
Ib
PERIOD C
DISCHARC
DATES
FROM-TO
72-11-13
to 11-24
73-04-12
to 04-27
73-05-23
to 05-31
73-10-24
to 10-31
72-04-05
to 04-07
72-04-24
to 05-03
72-05-06
to 05-12
72-10-15
to 10-27
72-11-12
to 11-21
73-04-18
to 05-20
72-05-15
b 7 2-05-25
72-10-17
to 10-26
73-04-09
to 04-18
73-10-12
to 10-18
72-10-30
to 12-01
73-04-02
to 04-30
F
,E
VI
3
o
>*
12
16
9
8
3
10
7
13
10
32
11
10
10
7
32
'i
-------
Table I. Continued.
COMMUNITY
Brownstovn
Township —
Wayne County
Continued
Brown City
Byron Center
Caoden
Capac
POPULATION
DESIGN CONN
1050
1850
600
1400
1360
1142
405
1279
LAGO
to
i
2
3
2
2
CELL 1
25 G o. z
2 -< 3 1-1
7.7
6.5
3.3
7.0
60
72
69
72
DH CAPACIT
CELL 2
5 G g. z
10.8
6.5
2.6
7.0
60
72
60
72
CELL 3
3 O flu SB
&< U M
4.5
72
DISCHARGE DATA - EFFLUENT 0
FLOW PATTERN
Bl
Al
A/
Al
A4
A4
A4
H
%
M
(H
*0
45
55
10
1
14
PERIOD OF
DISCHARGE
DATES
FROM-TO
73-10-29
to 11-15
72-04-10
to 04-24
73-04-25
to 05-03
73-10-19
to 11-02
73-05-08
to 06-01
72-09-06
to 09-15
72-10-30
to 11-07
72-11-17
to 11-21
73-03-22
to 03-30
73-05-01
to 05-09
73-10-31
to 11-07
72-04-21
to 05-15
72-10-27
to 11-11
72-11-20
to 11-30
CO
§
17
15
9
11
6
10
8
9
9
8
25
17
8
CHEMICAL
CO h
13
11
8
8
6
8
4
c
5
6
6
6
22
12
6
Susp.
BOD Sol.
(Bg/1) (mg/1)
RANGE AVG RANGE AVG
9-15
8-55
13-32
5-14
12-40
13-24
23-27
8-19
14-22
31-35
6-10
1-12
4-45
4-6
5-7
11
25
21
8
24
21
25
13
18
33
8
5
16
5
6
31-62
15-62
8-86
5-28
25-64
27-84
41-84
6-21
20-25
47-72
7-26
15-24
13-68
12-43
22-46
49
35
38
15
45
46
60
12
22
54
21
20
32
20
29
UALITY
FECAL COLI
CO t-
10
11
8
7
3
7
8
7
15
8
16
No
No
EPA STD.
RANGE 200 400
4.10-420
4.30-130
4.10-1300
*C 10-340
X100
« 10-1300
410-60
4: 10-50
A 10-90
410-160
£10-8000
data
data
*
«
X
X
*
*
*
X
*
*
*
-
*
X
X
X
*
X
X
X
SHEET
3
NOTES
* Ice out
about 4-15
Total coll
only
Total coll
only
§
!
f
J?
I
I
s-
-------
Table 1. Continued.
COMMUNITY
Capac
Continued
Carleton
Carson City
Coleman
Elkton
POPULATION
DESIGN
1400
2400
1500
2000
CONN
1279
2314
1200
1295
->
2
5
2
3
3
LAGOON CAPACITY
CELL 1
1!
7.0
5.0
8.0
11.0
x ^
72
72
96
72
CELL 2
li
7.0
4.5
Cei:
4.4
8.0
5.5
tl] f)
Q >-'
72
L *4
84
96
72
CELL 3
H o
4.5
Cel
5.8
5.5
|i
72
L 05
84
72
[FLOW PATTERN
A4
A4
A4
Al
Al
Al
Al
Al
Bl
Al
A
Al
u
o
CO
0
15
15
5
15
15
25
PERIOD OF
DISCHARGE
DATES
FROM TO
73-03-05
to 03-14
73-04-01
to 04-30
73-10-17
to 11-09
72-04-26
to 05-05
72-05-10
to 06-01
72-11-23
to 12-12
73-03-19
to 05-16
73-10-17
to 11-14
72-11-06
to 11-16
73-04-01
to 04-12
72-05-01
to 05-05
72-10-18
to 10-31
73-04-11
to 04-30
73-10-16
to 11-02
72 May
72 Oct
73-05-02
to 05-08
VI
1
iU
30
23
10
22
20
48
28
11
12
I
14
20
16
DISCHARGE DATA - EFFLUENT QUALITY
CHEMICAL
E3AYS
ffLING
7
20
17
4
i
6
14
4
11
7
c
11
11
14
BOD
(mg/1)
RANGE AVG
17-20
4-21
2-10
11-34
10
8-25
2-53
5-12
14-52
8-14
32-75
3-23
15-34
1-17
16-21
18
12
5
22
10
15
22
8
25
10
51
15
21
6
18
Susp.
Sol.
(mg/1)
RANGE AVG
14-33
13-90
3-59
32-81
7-41
24-48
10-84
12-18
12-53
12-56
10-50
5-32
16-92
2-19
51-90
24
37
30
62
20
39
46
14
24
26
32
16
49
10
68
FECAL COLJ
'# DAYS
'SAMPLING
6
21
17
7
19
12
35
11
11
7
e
9
8
10
N
RANGE
410-4800
*10-240
AlO-800
X10-140
A. 10-20
10-770
A10-50
AlO-10
* 10-10
.£. 10-400
-10
-------
Table 1. Continued.
COMMUNITY
Elkton
Continued
Fennvllle
Fowler
Fovlerville
Hemlock
POPULATION
DESIGN CONN
1800
1400
2000
1400
810
1000
1990
1390
LAGOON CAPACITY
Cfl
3
3
3
2
3
2
CELL 1
|G EJB
2 -4 u M
< >- Q ^
10.0
8.0
6.0
5.7
72
78
72
60
CELL 2
3 U S 5!
CA •< bl M
4.0
8.0
6.0
8.7
72
10.2
72
66
CELL 3
$ < U *
+;Z} S^,
4.0
6.0
72
72
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
A
A4
A4
Bl
A]
Bl
u
g
t-l
w
sg
a.
0
20
0
20
PERIOD OF
DISCHARGE
DATES
FROM-TO
73-10-15
to 10-2
72-04-05
to 04-11
72-06-13
to 06-22
72-11-14
to 12-01
73-04-06
to 04-15
72-11-13
to 11-17
72-12-07
to 12-14
73-04-0!
72-09-06
to 09-11
72-11-06
to 11-21
73-04-05
to 04-17
73-11-06
to 11-14
72-03-28
to 04-07
72-05-02
to 05-10
72-06-01
to 06-06
72-09-27
to 10-12
72-10-30
to 11-08
W
5
7
10
17
8
5
8
6
16
13
c
10
9
6
16
9
CHEMICAL
9 DAYS
SAKPLING
5
i
8
13
6
i
4
4
4
8
7
7
4
7
3
BOD
(mg/1)
RANGE AVG
1-7
11-16
6-30
7-40
11-16
4-7
8-10
2-6
4
3-8
18-54
16-66
32-44
21-76
32-42
4
13
16
15
13
6
9
3
4
5
44
37
38
40
36
Susp.
Sol.
dug/1)
RANGE AVG
2-7
21-41
17-80
13-59
36-86
10-21
10-22
3-14
2-5
5-11
6-16
36-60
22-34
24-46
24-54
4
34
33
40
55
15
14
10
3
7
10
53
26
40
35
FECAL COL I
V DAYS
SAMPLING
6
i
7
i
c
4
8
6
7
6
4
3
4
RANGE
,£.10-10
^.10-180
* 10-400
X 10-800
^•10-50
^10-40
^10-170
^10
^10-890
2000-10000
30-960
^10-80
90-3900
60-1500
EPA STD.
200 400
X
X
X
X
X
X
X
X
X
4700
315
X
340
240
X
X
X
X
X
X
X
X
X
4700
X
X
X
240
SHEET
5
NOTES
Ice cover
until 4-15
I
!
I
s
Cn
3-
I
-------
Table 1. Continued.
COMMUNITY
Hemlock
Continued
Ithaca
Kent City
POPULATION
DESIGN CONN
1400
3500
900
1390
2420
700
I
LAGOON CAPACin
3
u
2
3
3
CELL 1
SG si
is gc
5.7
15.1
4.5
60
72
60
CELL 2
«< x-> H «
3 O B, S!
pi < [d M
^ *"^ Q %«/
8.7
9.8
2.0
66
72
60
CELL 3
S c? o. a
Orf •< b] tH
9.6
2.0
72
84
DISCHARGE DATA EFFLUENT QUALITY
FLOW PATTERN
Al
Bl
El
Al
A2
A3
A3
Al
"A3
A3
Al
Al
' Al
Al
Al
Al
|°
u
20
0
0
24
15
15
10
PERIOD OF
DISCHARGE
DATES
FROM-TO
7 3-04-05
to 04-18
73-04-30
to 05-11
73-10-22
to 10-29
72-03-20
to 03-24
72-04-10
to 04-20
72-05-08
to 05-23
72-09-25
to 10-09
72-11-20
Eo 11-29
73-63-31
to 04-26
73-05-21
to 06-01
Oct 8
72-04-27
to 05-04
72-10-30
to 11-11
73-03-26
to 03-3a
73-04-11
to 04-14
73-05-21
to 05-24
73-11-04
to 11-12
1
14
12
8
5
11
16
15
10
17
12
8
19
5
4
4
9
CHEMICAL
» DAYS
SAMPLING
9
9
5
4
5
6
5
4
6
7
17
4
-
3
7
BOD
(mg/1)
RANGE AVG
18-36
18-32
13-19
11-34
16-40
12-52
4-8
16-19
12-70
20-40
16-37
3-15
27-32
17-23
7-9
7-11
26
23
15
20
22
28
6
17
40
27
14
S
28
19
8
9
Susp.
Sol.
(mg/1)
RADGE AVG
6-32
20-40
21-41
7-30
3-31
22-86
3-14
3-40
25-70
3-31
34-64
16-40^
No dat
— J
No dat
T4-18
No dat
20
25
31
17
20
50
8
16
45
19
43
26
I
17
FECAL COL I
# DAYS
SAMPLING
12
9
5
3
9
11
7
6
14
3
10
16
6
2
3
RANGE
180-4800
^.10-50
-10-10
.* 10-1380
^10-35000
^10-190
46 10-20
^•10
^W. 0—120
-110-350
A10-300
^10-1100
* 10-50
•*io
X.10
EPA STD.
200 400
490
X
X
X
500
X
X
X
X
X
X
*
*
X
*
830
JL
X
X.
1720
JL
X
X
X.
X
X
X
X
X
X
SHEET
6
NOTES
Ice cover
jntil 4-15
is?
re
-------
Table 1. Continued.
COMMUNITY
Laingsburg
'.akeview
Haybee
Memphis
Millington
POPULATION
DESIGN
1300
1150
1050
2000
1800
CONS
1100
1100
485
1120
1500
LAGOON CAPACITY
I
3
3
3
2
2
CELL 1
33 ^
< -^ H in
W U d. 55
•2 ^--
6.5
3.7
2.5
8.0
8.8
96
72
78
72
72
CELL 2
X X-
•rf ^ H W
[u U PT ^
Oj •< Ul l-<
-------
Table 1. Continued.
5?
COMMUNITY
Moienci
Mulllken
North Branch
Ovid
POPULATION
DESIGN
2850
750
1300
1600
CONN
2200
450
1100
1870
LAGOON CAPACITY
«j
o
=Sfe
2
3
3
CELL 1
w t?
52
14.8
2.5
8.9
1C *~*
H V3
P-. yz
W M
Q "*~*
84
60
72
CELL 2
W CJ
35
13.9
2.5
4.3
JK *"*
H c/3
E 2
U M
O -^
84
72
72
11
CELL 3
W Q
2.5
4.3
7.0
33 •—
H U5
a. z
U t-l
0 v-
84
72
78
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
Al
Al
A3
A2
Al
Al
~A1
ua
j
i-<
w
oB
!i
0
10
1
20
10
15
PERIOD
DISCHAR
DATES
FROM- TO
72-03-27
to 04-08
72-05-02
to 05-16
72-10-02
to 10-13
72-11-03
to 11-10
73-03-22
to 04-06
73-04-23
to 05-04
• 73-10-08
to 11-08
73-04-13
to 05-23
72-04-12
to 04-21
72-10-09
to 10-13
73-04-06
to 04-24
73-11-05
to 11-16
72-04-24
to 05-15
72-11-01
to 11-17
^71-03-28
to 04-08
OF
GE
w
5
Q
=fe
12
li
12
6
Ib
12
30
40
10
c
9
12
22
c
ii
CHEMICAL
# DAYS
SAMPLING
10
10
10
6
12
9
18
7
i
7
8
8
8
BOD
(mg/1)
RANGE AVG
2-36
9-32
1-6
5-9
5-15
7-22
3-9
23-47
2-9
7-36
4-13
6-15
7-18
20
23
4
6
8
13
5
34
6
18
8
8
11
Susp.
Sol.
(mg/1)
RANGE AVG
3-27
10-69
1-9
32-80
2-18
5-73
3-84
36-101
2-15
5-39
7-35
12-57
9-60
12
2!
4
50
12
25
27
61
V
18
19
29
32
FECAL COLI
# DAYS
SAMPLING
10
10
5
6
12
11
15
18
6
5
7
4
9
8
9
RANGE
^S.10-20
-616
^=10-10
-W. 0-800
«10-20
<10-190
«.10-400
<^10-40
^.10-630
AlO-40
4.W
'"
-------
Table 1. Continued.
COMMUNITY
Ovid
Continued
Pentwater
Pigeon
Plainfield
Township
Port Sanilac
Potterville
POPULATION
DESIGN
1600
1500
1300
370
700
1200
1400
CONN
1870
1385
1175
300
500
900
1360
LAGOON CAPACITY
CELLS
3
4
2
2
3
CELL 1
<: ^ H «
(d CJ O-, 55
< —
4.5
6.9
6.5
2.0
4.7
7.0
0 *"
72
48
72
60
72
60
CELL 2
< ^ H 3
cT
C4
-------
Table 1. Continued.
5?
COMMUNITY
Reading
Reese
Saint Charles
Sand Lake
POPULATION
DESIGN CONN
1250
1450
2400
448
1120
1200
1950
365
LAGOON CAPACITY
to
i
2
2
2
2
CELL i
•t ^ f-. CO
td U (L, T&
S5- w £i
7.6
7.2
11.0
2.0
72
72
60
96
CELL 2
•< /-x H to
D£
-------
Table 1. Continued.
COMMUNITY
Scottville
Shepherd
Stantop
Suttons Bay
POPULATION
DESIGN CONN
1900
1500
500
700
1140
1460
400
500
LAGOON CAPACITY
3
a
o
*a
2
2
2
3
CELL 1
s ^
< ^> H to
wo a* ^
53. WC
8.9
10.6
4.0
2.5
120
72
84
54
CELL 2
S G P. z
55- g~
10.1
6.1
3.0
2.5
120
72
96
60
CELL 3
50 *•>
•< /-x H W
bd O &4 55
03 < W w
•3 ~ Q~
2.0
60
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
A3
A4
I
to
V) £
3;
Ik 1-
10
Al 15
/
A4
A4
•A4
A4
Al
Al
0
15
15
1
PERIOD OF
DISCHARGE
DATES
FROM-TO
72-04-28
to 05-19
72-11-01
to 11-28
73-04-01
to 06-07
$2-03-28
to 04-19
72-04-29
to 05-25
72-11-01
to 11-30
73-10-15
to 10-31
72-05-01
to 05-08
72-10-23
to 10-27
73-03-2$
to 04-16
72-04-22
to 05-22
72-09-12
to 09-20
72-11-20
to 12-18
10-03
to 11-06
CO
1
^fc
8
28
68
22
36
30
17
8
b
1*
30
9
9
CHEMICAL
z
w t-
n
% 0
(
iy
39
15
23
21
8
E
6
8
15
4
—5
BOD
(mg/D
RANGE AVG
37-60
6-35
11-80
11-29
10-50
5-44
13-30
7-28
7-28
8-23
10-15
5-9
?-io
48
23
37
19
23
18
23
19
18
17
13
7
Susp.
Sol.
(ng/1)
RANGE AVG
17-74
3-38
7-170
12-72
6-68
2-82 '
10-40
11-33
11-23
12-36
12-62
12-20
3-37
54
21
25
44
32
16
19
19
15
30
34
14
12
FECAL COLI
t DAYS
SAMPLING
15
19
6
13
20
21
C
6
9
4
2(
4
(
RANGE
^10-130
^10-3400
* 10
290-31500
^10-1870
.410-760
^.10-40
A10-100
*10-70
^,10-10
^•10-100
^•10-210
^•10-40
EPA STD.
200 400
3.
X
X
2950
X
X
X
y.
x
X
X
X
X
800
X
7200
X
X
X
X
X
X
X
X
SHEET
11
NOTES
Ponds coverd
with ice
nearly all
this period
i
OS
c/j
a.
o
•8
o
-------
Table 1. Continued.
COMMUNITY
Vernon
Waldron
Wheat land
Township
Wright Township
Ottawa County
COPULATION
DESIGN CONN
900
600
1025
815
525
800
LAGOON CAPACITY
j
-J
4
*
3
2
3
CELL 1
X -^
•< ^ H en
W O pi "^
<: ^ Q *—
2.8
3.1
3.9
72
72
72
CELL 2
P3 "•
•rf --v t-< CO
•3 ^- Q —
3.0
3.1
3.0
72
72
72
CELL 3
•< .-* H co
W U B. Z
< ^ O -^
3.3
3.0
72
96
M
B
<:
8
t.
A4
A2
A4
e
CO
in g
gw
!fc M
10
5
PERIOD OF
DISCHARGE
DATES
FROM-TO
72-10-18
to 10-30
73-03-26
to 04-11
72-05-05
to 05-10
72-09-25
to 10-17
73-10-07
to 11
72-04-24
to 05-11
72-10-31
to 11-27
73-04-01
to 05-04
73-10-08
to 11-01
72-04-10
to 04-28
72-11-08!
to 11-13
72-12-11
to 12-13
73-04-08
to 04-llj
1
<*
13
16
6
23
18
28
34
24
19
6
j
4
DISCHARGE DATA - EFFLUENT QUALITY
CHEMICAL
§3
* &
9
11
4
15
10
24
19
6
5
j
T
BOD
(mg/1)
RANGE AVG
2-10
13-25
6-24
5-37
25-38
9-18
1-4
10-25
4-6
1-5
17-45
4
19
15
20
30
15
2
17
5
3
29
Susp.
Sol.
(mg/1)
RANGE AVG
6-22
22-102
72-88
12-70
72-120
6-50
5-56
37-92
3-30
10-38
42-52
10
49
80
33
101
42
2U
65
15
20
35
FECAL COLI
* a
8
9
4
13
10
19
11
10
3
RANGE
^J.0-20
^.10-220
^10
^10-6300
^ 10-180
^10-10
A10-90
*• 10-680
A10-80
EPA STD.
200 400
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
SHEET
12
NOTES
I
-------
Table 1. Continued.
COMMUNITY
Yale
Cooper svllle
POPULATION
DESIGN CONN
1800
3600
1505
2400
LAGOON CAPACITY
,j
a
i_>
2
3
CELL 1
Is 15
11.5
10.0
72
72
CELL 2
II 11
6.5
10.0
72
72
CELL 3
5 G a. 55
2 < W M
< C- o ^
*12.0
' ~~
*96
DISCHARGE DATA - EFFLUENT QUALITY
2
s
<
g
S!
Al
•]
w
g
St l-<
5
3i
~
PERIOD OF
DISCHARGE
DATES
FROM- TO
72-04-17
to 04-28
72-05-06
to 05-20
73-04-16
to 04-27
'73-05-07
to 05-18
73-10-22
to 11-02
72-11-01
to 11-15
73-05-08
to 05-15
CO
I
12
IS
12
12
11
16
8
CHEMICAL
P
n M
£ ri
h M
10
1C
10
10
10
11
- 4
BOD
(mg/1)
RANGE AVG
16-53
3-6
5-11
5-12
2-3
2-10
2-7
24
4
7
8
3
4
5
Susp.
Sol.
(mg/D
RANGE AVG
38-109
10-25
14-76
20-46
11-40
4-56
14-30
46
19
33
28
19
28
20
FECAL COLI
i
5 K>
g|
Sfc «
10
9
10
10
10
No
5
RANGE
^.10-1140
^10-720
^.10-30
^.io-io
^10-20
data
^.10
EPA SID.
200 400
X
X
X
X
X
X
X
X
X
X
X
X
SHEET
13
NOTES
*Total for
cells 3 & 4
I
3
<£,
50
I
I
f
-------
114
Pierce
Table 2. Typical data showing seasonal trends in coli concentrations, lagoon effluents, Michigan.
COMMUNITY
Ashley
(Spring 1972 Discharge)
Ashley
(Spring 1973 Discharge)
Capac
(Spring 1972 Discharge)
SAMPLE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
__
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
9
10
11
12
DATE
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
2-28
3-23
3-24
3-25
3-26
3-27
3-28
3-29
3-30
4-23
4-24
4-25
4-26
4-27
3-28
3-29
3-30
3-31
4-3
4-4
4-5
4-6
4-7
4-10
4-11
4-12
TOTAL COLI
120,000
322,000
265,000
355,000
450,000
51,000
23,000,000
290,000
117,000
1,230,000
66,000
83,000
73,000
68,000
78,000
67,000
8,100
31,000
1,600
400
9,000
500,000
11,600
68,000
46,000
55,000
540,000
74,600
300,000
48,000
28,000
10,500
6,900
6,300
10,800
65,000
660,000
1,600
21,000
22,000
23,000
56,000
4,800
47 ,000
31,000
12,400,000
645,000
150,000
865,000
1,200,000
1,800,000
91,000 000
860,000
1,850,000
496,000
52,300,000
35,000,000
FECAL
2,600
3,010
2,750
3,000
12,100
900
36,000
810
1,160
1,030
490
400
320
570
360
950
90
20
*10
•MO
*10
-------
Performance of Raw Waste Stabilization Lagoons in Michigan
115
Table 2. Continued.
COMMUNITY
Capac Continued
(Spring 1972 Discharge)
Capac
(Spring 1973 Discharge)
Ovid
(Winter-Spring 1972)
Ovid
Ovid
(Fall 1972 Discharge)
SAMPLE
NO.
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
1
2
3
4
5
DATE
4-13
4-14
4-17
4-18
4-19
4-20
4-21
4-24
4-25
4-26
4-27
4-28
5-01
5-02
5-03
4-02
4-03
4-04
4-05
4-06
4-09
4-10
4-11
4-12
4-13
4-16
4-17
4-18
4-19
4-20
4-23
4-24
4-25
4-26
4-27
4-30
3-14
3-15
3-16
3-17
3-18
3-20
3-21
3-22
3-23
3-24
3-27
3-28
3-29
4-24
4-25
4-26
4-27
4-28
4-29
5-13
5-15
10-03
11-01
11-09
11-10
11-11
TOTAL COLI
3,000,000
9,180,000
630,000
55,000
5,100,000
900,000
620,000
26,000
29,000
52,000
54,000,000
118,000
65,000
39,000
34,000
3,200
17,000
33,000
3,200
30,000
14.200
37,000
11,000
420,000
9,300
6,700
5,600
3,900
7,500
54,000
22,000
4,500
420,000
260,000
18,000
73,000
2,900,000
1,900,000
2,300,000
7,050,000
5,100,000
377,000
595,000
460,000
590,000
37,800
2,300,000
680,000
540,000
12,000
22,000
41,000
30,000
42,000
94.000
720,000
28,000,000
9,300
400
2,900
800
2,000
FECAL
3,000
2,800
790
780
4,000
7,000
1,150
450
400
850
1,900
160
170
80
30
10
10
20
50
240
20
50
30
10
170
10
100
10
50
40
10
10
90
50
140
150
30,000
1,000
50,000
53,200
53,500
2,800
20,500
53,000
42,000
2,160
1,580
2,610
100
400
40
90
40
250
390
-ilO
170
-10
-10
-10
-10
-10
COMMENTS
Lagqons were full on
March 14 and over-
flowing under iced-
over conditions until
about April 15. Con-
trolled discharge began
under ice-free
conditions on April 24.
Discharged from cell
No. 3 under controlled
conditions following
several months' storage.
-------
116
Pierce
Table 2. Continued.
COMMUNITY
Ovid Continued
(Fall 1972 Discharge)
Ovid
(Winter-Spring
1973 Overflow)
Rose City
(Winter-Spring 1972
Overflow & Discharge)
Rose City
(Fall 1972 Discharge)
Rose City
(Winter 1972-73 Overflow)
SAMPLE
NO.
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
DATE
11-12
11-13
11-14
11-15
11-16
11-17
1-16
1-17
1-18
1-19
1-20
1-21
1-22
3-12
3-13
3-14
3-15
3-28
3-29
3-30
3-31
4-02
4-03
4-04
4-05
4-06
4-23
4-24
4-25
4-26
4-27
3-06
3-07
3-08
3-09
4-08
4-09
4-10
4-11
5-06
9-27
9-28
10-17
10-18
10-19
10-20
10-21
11-08
11-09
11-10
12-19
12-20
12-22
1-25
1-26
1-27
1-28
1-30
1-31
2-01
2-02
3-19
3-20
TOTAL COL I
1,900
1,400
6,700
22,000
4,400
19,000
1,300
1,800
1,900
1,600
5,700
5,000
5,200
330,000
230,000
340,000
43,000
1,000
100
31,000
110,000
4,500
74,000
6,300
76,000
42,000
42,000
45,000
24,000
1,500
2,000
4,100,000
4,900,000
2,100,000
1,300,000
800,000
400,000
1,700,000
LI, 200, 000
1,700,000
59,000
490,000
47,000
2,000
3,000
4,200
1,800
230,000
210,000
48,000
4,300
2,500
1,800
35,000
240,000
600,000
23,000
5,700,000
2,200,000
6,000,000
2,300,000
'8,000,000
380,000
FECAL
*10
-*10
•4.10
30
10
^.10
-tlO
*10
-.10
*. 10
90
110
30
4,100
3,100
4,800
1,600
'10
*10
-C10
-610
10
40
160
70
•*10
<10
10
-tlO
^.10
10
60,000
110,000
10,000
10,000
16,000
12,000
47,000
31,000
3,300
10
290
50
10
10
30
-slO
360
3,700
1,800
«10
*10
-t 10
4,500
2,000
30,000
2,900
9,100
24,000
7,200
33,000
3,400
540
COMMENTS
Ice cover nearly off
on March 12.
Ponds still ice-coveret* .
Cell No. 1.
Cell No. 1
Cell No. 1
Cell No. 1
Ponds covered with ice.
Ice about out.
-------
Table 2. Continued.
Performance of Raw Waste Stabilization Lagoons in Michigan 117
COMMUNITY
Rose City
(Spring 1973 Discharge)
Pentwater
(Spring 1972 Discharge)
Pentwater
(Spring 1973 Discharge)
Scottville
(Spring 1972 Discharge)
SAMPLE
NO.
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
DATE
4-09
4-10
4-11
4-17
4-18
4-19
4-23
4-24
4-24
4-24
4-25
4-26
4-27
4-28
5-01
5-02
5-03
5-04
5-05
4-02
4-03
4-04
4-05
4-06
4-09
4-10
4-11
4-12
4-13
4-16
4-17
4-18
4-19
4-20
4-23
4-24
4-25
4-26
4-27
4-30
5-01
5-02
5-03
5-04
5-01
5-02
5-03
5-04
5-05
5-08
5-09
5-10
5-11
5-12
5-15
5-16
5-17
5-18
5-19
TOTAL COLI
480,000
54,000
790,000
120,000
3,400
8,000
2,000
4,800
6,100
8,000
131,000
97,000
56,000
146,000
86,000
190,000
89,000
310,000
105,000
800
2,000
3,200
1,300
40,000
36,000
2,100
300
26,000
52,000
34,000
17,000
23,000
400
1,900
3,900
29,000
38,000
3,500
5,800
900
2,300
24,000
6,600
5,200
37,000
38,000
52,000
213,000
38,000
32,000
113,000
2,500
780,000
9,300,000
43,000
83,000
42,000
14,200
2,000
FECAL
10
50
150
^10
-.10
20
— 10
-10
10
- 10
^10
— 10
—10
— 10
-10
-elO
10
-10
70
—10
—10
10
•cio
—10
<10
— 10
—10
*10
40
20
10
-10
—10
— 10
20
10
310
— 10
—10
-10
—10
20
*10
20
30
30
10
130
70
70
-.10
-110
—10
-S10
* 10
-£10
— 10
COMMENTS
-------
118 Pierce
Table 2. Continued.
COMMUNITY
Scottville
(Fal3J1972 Discharge)
Scottville
(Spring 1973 Discharge)
Shepherd
(Spring 1972 Discharge)
SAMPLE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
1
2
3
4
5
6
1
2
3
4
5
6
7
a
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
DATE
11-01
11-02
11-03
11-06
11-07
11-08
11-09
11-10
11-13
11-14
11-15
11-16
11-17
11-20
11-21
11-22
11-24
11-27
11-28
4-16
4-17
4-18
4-19
4-23
4-24
3-29
3-30
4-04
4-05
4-06
4-10
4-11
4-12
4-13
4-17
4-18
4-19
4-20
4-24
4-25
4-26
4-27
5-01
5-02
5-03
5-04
5-08
5-09
5-10
5-11
5-15
5-16
5-17
5-18
5-22
5-23
5-24
5-25
TOTAL COLI
6,500
9,600
26,000
190,000
22,000
9,000
12,000
140,000
34,000
230,000
230,000
41,000
210,000
21,000
100,000
53,000
90,000
370,000
400,000
25,000
19,000
2,300
25,000
37,000
3,700
1,100,000
1,400,000
730,000
764,000
625,000
490,000
7,300,000
126,000
94,500
77,000
104,000
33,000
31,000
40,000
54,500
20,000
9,000
36,500
250,000
41,000
14,900
65,000
89,000
250,000
8,500
71,000,000
8,000,000
11,600,000
9,800
96,000
98,000
4,700,000
51,000
FECAL
60
20
160
20
200
410
30
580
230
1,100
710
...
3,500
70
2,801
90
650
970
2,700
10
410
440
-6.10
*10
4.10
7,000
10,000
6,000
18,600
31,500
4,200
1,100
390
990
290
2,390
490
870
650
390
150
50
40
1,870
560
130
170
1,190
110
10
440
^10
^10
-610
^.10
10
40
20
COMMENTS
-------
Table 2. Continued.
Performance of Raw Waste Stabilization Lagoons in Michigan 119
COMMUNITY
Shepherd
(Fall 1972 Discharge)
SAMPLE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
DATE
10-30
10-31
11-01
11-02
11-06
11-07
11-08
11-09
11-13
11-14
11-15
11-16
11-20
11-21
11-22
11-27
11-28
11-29
11-30
OTAL COL1
23,000
1,600
2,100
1,000
2,100
2,200
3,300
2,300
2,000
1,500
3,000
3,400
300
2,800
32,000
20,000
8,600
15,000
1,900
FECAL
10
410
10
xio
-U.O
40
40
20
30
.410
30
20
10
,610
30
760
370
350
X10
COMMENTS
-------
9O--
80--
70--
6O-
50-
V40--
30--
20--
10-•
SUSP. SOLIDS
3 or more CELLS
SUSP SOUDS-2 CELLS
BOD-3 or more CELLS
BO D- 2 CELLS
90
—r
O.I
10
50
99
99.9
(X) PROBABILITY OF NOT EXCEEDING Y
Figure 1. Comparison of effluent quality 2-cell systems vs 3 or more with long period storage before discharge, Michigan.
-------
50- -
— 4O- -
30--
20--
10--
8
•S,
f
I
f
I
I
1
3-
O.I
1
10 50
(X) PROBABILITY OF NOT EXCEEDING Y
90
99.9
Figure 2. Comparison of effluent quality 2-cell systems vs 3 or more with long period storage before discharge, Nfichigan.
-------
90--
8O-
70--
60--
> 40--
SO--
20- -
10- •
to
10 50 90
(X) PROBABILiTY OF NOT EXCEEDING Y
99
99.9
Figure 1 Effluent quality 49 waste stabilization lagoons with long period storage before discharge, Michigan.
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 123
SUPPLEMENTARY STUDIES OF LAGOONS OF VARIOUS TYPES
The preceding report sets forth the results of
studies, conducted by this investigator during the fall
of 1973, of performance of 49 municipal lagoon
systems in Michigan treating raw wastewater. These
systems were selected for study because, individually
and collectively, they typify features of construction,
loadings, and maintenance and operational practices
which readily accommodate a common mode involv-
ing long period storage followed by control short
period discharge. Monthly records of one to two
years duration, supplemented by chemical and bacter-
iological data on samples collected during discharge
periods, provide an excellent indication of the per-
formance capability of the process and means by
which the adverse effects on the process of prolonged
periods of ice cover common to many northern states
may be overcome.
Supplementary studies were undertaken during
the summer of 1974 with the following objectives:
To evaluate performance of raw waste stabilization
lagoons in other northern states when managed in
essentially similar ways; to examine the methods in
use and results of chlorination for coliform bacteria
destruction both at lagoons so managed and those
with continuous discharge; and to collect available
information on nitrification phenomena. Results of
these studies led to an examination of performance of
lagoons used as oxidation ponds following trickling
filters at several typical installations and observations
of performance of an aerated lagoon followed by
chemical precipitation for phosphorus removal and
by chlorination for coli destruction.
Supplementary Studies of Raw Waste
Stabilization Lagoons with Long
Period Storage and Intermittent
Discharge
Several of the northern states have adopted a
program with criteria for design and operational
control of raw waste stabilization lagoons very similar
to those in Michigan. Typical of these are the
Minnesota and North Dakota programs.
Minnesota
As in Michigan the Minnesota Pollution Control
Agency has established criteria for raw waste sta-
bilization lagoon loadings in the 100 person per acre
range with provision for long period storage, restric-
ting discharge of effluents to early spring and late fall
with total retention from May 15 to October 31 and
during winter months. Discharge is authorized by the
state agency after testing of samples of lagoon
contents at point of discharge show BODj not greater
than 25 mg/1, total suspended solids not greater than
30 mg/1, and fecal coli concentrations not to exceed
200 MPN/100 mis. Present requirements call for
sampling prior to and during discharge and reporting
of results using the standard state report forms.
Some elements of the state program essential to
effective performance are the following, excerpted
from their Recommended Procedure for Sampling
and Discharging of Wastewater Stabilization Ponds.
Prior to any impending pond discharge a
representative pond sample(s) shall be taken to
determine pond effluent quality. This sample
shall be analzyed for 5-day biochemical oxygen
demand (BOD,), Total Suspended Solids
(TSS), and fecal coliform bacteria content In
municipalities with unusual industrial wastes
other tests by special request of the Agency
may be required.
All pond discharges shall have a 5-day
BODj concentration not to exceed 25 mg/1, a
TSS concentration not to exceed 30 mg/1, and a
fecal coliform bacteria count not to exceed 200
most probable number (MPN/100 ml).2
Notification of proposed discharge of the
ponds shall be made to either the district
representative in your area or the Section of
Municipal Works (MPCA). The request can be
written or by telephone and must Include the
analytical results of the representative pond
sample. Should the results of analysis of the
required samples exceed effluent standards, the
sampling procedures shall be repeated until
effluent standards can be met. Effluent may be
discharged only when it is in conformance with
the applicable regulations and terms of the
permit issued for the disposal system.
After notification, and if there is no
objection by the staff, discharge should be
accomplished by properly utilizing gate adjust-
ment in the outfall structure. Utilization of gate
adjustments should allow the pond to be
lowered down to the 18-inch to 1 foot level. At
no time should the pond be lowered beyond
the 1 foot of depth level.
2If fecal coliform group organisms exceed 200
MPN/100 ml, the effluent should be disinfected by use of
chlorine or other approved methods to bring it within
standards.
-------
124 Pierce
Caution should be used when discharging
so a minimum of bottom scouring occurs. A
rapid 01 uncontrolled discharge could cause
bottom scouring, thereby removing the seal.
Calculation of needed storage capacity
should be made by the operator. If more
storage capacity is required than provided for
by one release of a secondary pond, a refilling
of the secondary pond and a repeat of pro-
cedures should be undertaken (NOTIFICA-
TION FOR SECOND DISCHARGES IS ALSO
REQUIRED).
When refilling the secondary from the
primary for a second discharge, the operator
should only utilize gates in the control struc-
ture. Draw off from the primary should be
conducted carefully because short circuit
effects can occur if the refilling is too rapid or
bottom discharge valves are utilized. Improper
draw down of the primary could cause poorly
treated wastes to fill the secondary pond,
thereby lowering the quality in the secondary
pond so that further time would be needed to
stabilize, thereby causing further delay before
tests show the quality is satisfactory for a
second discharge.
A minimum of two weeks of actual
discharging is recommended. This does not
include time for testing between discharges.
The discharge should be slow and continuous in
nature with daily adjustment of the outfall
gates.
During discharge testing ... listing shall be
undertaken to substantiate effluent quality, i.e.,
twice a week until the discharge is complete.
The results of tests during discharge should be
submitted on the next regular monthly report
form.
Ponds do not operate themselves; they
require proper operation and regular mainten-
ance if extensive and expensive renovations are
to be eliminated.
The state agency summarized the results of
laboratory analyses of samples collected at typical
municipal raw wastewater lagoons during fall 1973
and spring 1974. In the fall, BOD5 at 36 of the 39
installations sampled was less than 25 mg/1 and
suspended solids less than 30. Tests for fecal coli were
made on samples from 17 installations and for total
coli at 14 other. All fecal coli concentrations were
200 or less per 100 mis and 10 of the 14 tested for
total coli were 1000 or less with maximum 3800 for
the other 4. Effluent quality for the spring discharge
as measured by these parameters was generally
similar. Tests were made at 49 municipal installations.
BOD5 at 5 lagoons exceeded 25 mg/1 with 3
exceeding 30, the high value being 39. Suspended
solids values ranged from 7 to 128 with 16 of the 49
exceeding 30 and 10 greater than 40. Only 3 of the
45 tested for fecal coli exceeded 200 per 100 mis.
North Dakota
Design criteria and modes of operation esta-
blished by the state regulatory agency (Department
of Public Health) are similar in most respects to those
in effect in Michigan and Minnesota. One significant
difference is the firm requirement, adopted early this
year, that at least three cells be provided and that the
area in the primary cell be approximately one-half the
total surface area of all the ponds. Total organic
loading on the primary cell may not exceed 30
pounds of BOD5 per acre per day and the total
loading for all ponds may not exceed 20 pounds per
acre per day. Further, the total hydraulic loading,
including infiltration and inflow, shall be used to
determine the volume required to provide a minimum
storage capacity of 180 days between the 2 and 5
foot liquid levels. Although provision must be made
for series operation "to meet effluent standards and
provide for better nutrient reduction," both series
and parallel operation is encouraged to provide
desirable flexibility for circumstances when one cell
must be taken out of use for repair, enlargement or
for some other reason.
The standards state that "For winter storage
the operating level should be lowered before ice
formation and gradually increased to 5 feet by the
retention of winter flows. In the spring, the level in
the secondary cell can be lowered to any desired
depth providing the liquid meets effluent standards
and approval to discharge has been obtained."
Discussions with responsible personnel of the
state regulatory agency reveal that lagoon systems
built and operated in conformity with these princi-
ples can consistently meet EPA requirements for
BOD, and fecal coli and come within reasonable
range of the requirement for total suspended solids.
The value of regular operational control in accor-
dance with well established principles is recognized.
Upper Peninsula, Michigan
Several small communities in Michigan's Upper
Peninsula have constructed raw waste stabilization
lagoons during the last 3 years. Five of these systems
had a spring discharge this year following several
months storage during the rigorous northern winter
with long periods of ice and snow cover. These
systems are all approximately at design loading of
100 persons per acre. Operational and maintenance
practices conform to those outlined in this report for
Michigan communities. None of the systems have
chlorination.
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 125
Table 1. Discharge data, Upper Peninsula Lagoons, Spring 1974.
Community
Bessemer Township
(2 cells)
Bergland Township
(3 cells)
Wakefield
(2 cells)
Total Coli
Powers
(2 cells)
Gwinn
(2 cells)
Date BOD5 Suspended
0974) OM» «*
Ice breakup began 4/10
5-7
5-16
5-17
5-18
5-19
5-20
Ice breakup began 4/22
5-1
5-3 o
5-13 Z
5-16
Ice breakup began 4/19
4-24
4-29
5-6
5-13
5-20
; zero ice 4/24
--
10
16
13
19
18
; zero ice 4/26
u
3 2
3*
06
; zero ice 4/23
15
27
21
25
23
-
10
32
13
16
23
72
82
60
30
21
34
35
52
54
Fecal Coli
per 100 mis
<100
<100
<100
<100
<100
<100
<100
<100
<100
<100
100*
2100*
700*
300*
100*
Ice breakup began 4/8; zero ice 4/18
4-25
5-7
5-9
5-10
5-15
6-4
6-5
6-17
6-18
CO
•!_»
M
Q
o
2
3
a
G
o
3
&
o
%
3
rt
<5
I
140
<10
M
< 10
< 10
<10
Belding, Michigan
Studies conducted by the City of Belding on its
5-cell raw waste stabilization lagoons shed additional
light on performance of facilities of this type. Of
particular interest are the data on progressive nitrifi-
cation through the several cells operated in series and
related levels of BOD5 and suspended solids. Of
interest also are the data on coliform reduction by
chlorination of the effluent.
The project is designed for long period storage
and seasonal discharge with provision for spray
irrigation of the effluent on nearby lands. Studies
have been financed by EPA R&D Grant and a wealth
of information has been collected for a period of
several years.
Facilities
Raw wastes are collected by the municipal
sewer system from a population of about 4,000.
Some minor industrial wastes are included. At the
lagoon site wastes flow through a small anaerobic cell
followed by four larger cells operated generally in
series. Total surface area is about 55 acres, Cell No. 2
having about 20 acres, Cell No. 3 15 acres, and Cells
No. 4 and No. 5 each about 7.5 acres.
Performance
Wastes are generally weak by reason of exten-
sive infiltration of surface water into the sewer
system. This is reflected in Table 2 of the Laboratory
Analyses Report prepared by the certified resident
operator for samples collected on July 21, 1972.
These are typical values for late spring, summer, and
early fall conditions in the several lagoons. Typical
also are the values for samples collected from each of
the first four ponds in the series. The quality of the
raw waste varies widely depending on rate of infil-
tration and inflow at the time. Quality as measured
by most of the parameters undergoes little change in
the fourth and fifth lagoon.
-------
126 Pierce
Quality of the effluent from Pond No. 5 during
cold weather conditions is indicated in Table 3,
Samples were collected during two periods of dis-
charge of the chlorinated effluent to the river. Several
trends may be noted. During the January discharge
BOD5 dropped to a very low level. Suspended solids
concentrations also were markedly lower, probably
by reason of reduced algal concentration. Ammonia
nitrogen was very high compared with warm weather
levels, continuing to increase as water temperatures
became critically low in late January. Phosphorus
concentrations increased gradually over the period.
No coli were found in the chlorinated effluent.
Characteristics of the effluent from Pond No. 5
discharged to the river are shown again in the
following analyses (Table 4) conducted by the opera-
tor for the 1974 spring discharge. All ponds were full
and overflowing at that time with no ice cover.
Table 4 indicates that BOD5 concentrations
remain low at about the same level as in the preceding
November and that suspended solids concentrations
are beginning to rise with increase in algae popula-
tion. Significantly, ammonia nitrogen has dropped
prior to April 26 and continues to drop, rapidly
reaching mid-summer levels. Lowering in phosphorus
levels is also apparent. Total coli concentrations vary
for no apparent reason.
Nitrification
The seasonal fluctuation in ammonia concen-
trations, associated with changes in water tempera-
ture are clearly indicated in Table 5 and Figure 1,
data for which were derived from the plant operation
reports. Ammonia concentration (NH3-N) is consis-
tently below 0.5 mg/1 during July-September rising
gradually through October-January with little
nitrification during periods of ice cover mid-January
through March, remaining at the 10-15 mg/1 level
until sometime in May in 1972 and late March in
1973. The lagoon surface was ice covered in 1972
until late April and about one month earlier in 1973.
Table 2. Quality of contents of 5 lagoons operated in series at Belding, Michigan.
Analysis
D.O.
Ammonia Nitrogen
Nitrate Nitrogen
pH
Total Phosphorus
Ortho Phosphorus
Suspended Solids
Influent
Raw Sewage
0.0 mg/1
34.6 mg/1
0.1 6 mg/1
7.1
12.5 mg/1
10 mg/1
121 mg/1
Eff. from
Pond No. 1
0.0 mg/1
27.3 mg/1
0.2 mg/1
7.3
9.9 mg/1
7.8 mg/1
76 mg/1
Eff. from
Pond No. 2
27.8 mg/1
2.7 mg/1
0.44 mg/1
8.6
3.0 mg/1
1.6 mg/1
146 mg/1
Eff. from
Pond No. 3
11. 2 mg/1
0.4 mg/1
0.5 mg/1
8.6
2.5 mg/1
2.0 mg/1
31 mg/1
Eff. from
Pond No. 4
5.0 mg/1
0.6 mg/1
0.1 9 mg/1
8.0
4.4 mg/1
3.4 mg/1
17 mg/1
Eff. from
Pond No. 5
10.8 mg/1
0.5 mg/1
0.08 mg/1
8.6
2.9 mg/1
2.3 mg/1
22 mg/1
Table 3. Effluent quality-Pond No. 5, late fall and winter discharge.
Date
1973
11-5
11-7
11-13
11-20
11-22
D.O.
10.5
10.7
10.8
9.7
10.0
BOD5
3.0
8.9
10.3
9.4
8.7
Suspended
Solids
52
60
102
78
52
NH3-N
2.4
5.58
5.58
5.82
5.22
NO3-N
0.35
0.33
0.41
1.1
0.97
Total
P
2.7
3.9
3.9
3.9
3.5
Total Coli
(MF).
0
0
0
0
0
1974
1-15
1-18
1-22
1-25
1-29
Total Discharge - 57,559,000 gallons
9.7
10.9
8.2
5.0
10.5
7.2
1.4
5.4
1.2
2.4
9.5
11
13.5
12.5
30
5.7
5.96
7.4
9.0
10.8
Total Discharge - approximately 38 million gallons.
0.82
0.66
0.22
0.16
0.15
3.4
3.6
4.0
4.4
5.1
0
0
0
0
0
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 127
Table 4. Characteristics of the effluent from Pond No. 5.
Date
1974
T26~
4-29
5-1
5-6
5-7
5-8
5-13
D.O.
17.5
12.0
10.7
9.4
10.0
10.3
9.6
BOD5
6.7
10.5
7.8
8.9
9.8
7.0
9.1
Suspended
Solids
53
30
16
23
12
16
27
NH3-N
3.3
3.5
2.6
1.0
0.75
0.8
0.1
NO3-N
1.1
1.0
1.3
1.4
1.5
1.4
1.0
Total
P
2.8
2.9
3.0
3.2
2.8
2.7
2.5
Total Coli
(MF)
—
<100
<100
1800
--
5500
<100
Note: All chemical results expressed as mg/1.
14--
0 I N I 0 I J I F
Figure 1. Seasonal variation in ammonia nitrogen lagoon effluent, fielding, Michigan, April 1972 - August 1973.
-------
128 Pierce
Table 5. Data showing seasonal variation in ammonia nitrogen in lagoon effluent, Belding, Michigan, 1972-1973.
Date
1972
Mar. 20
Mar. 25
Mar. 30
Apr. 4
Apr. 14
Apr. 19
Apr. 29
May 4
May 9
June 16
June 21
June 26
June 30
July 6
July 1 1
July 17
July 21
July 26
July 31
Aug. 5
Aug. 15
Aug. 21
Aug. 25
Aug. 30
Sept. 4
Sept. 9
Sept. 14
Day of
Year
79
84
89
94
104
109
119
124
129
167
172
177
181
187
192
198
202
207
212
217
227
233
237
242
247
252
257
NH3
(mg/1)
17.2
27
19
17
13
13.5
8.0
6.8
2.0
1.1
1.1
1.1
0.6
0.4
0.3
0.5
0.3
0.03
0.05
0.04
0.3
0.3
0.3
0.03
0.2
0.06
Date
Sept. 19
Sept. 25
Sept. 29
Oct. 9
Oct. 14
Oct. 19
Oct. 25
Oct. 30
Nov. 15
Nov. 18
Nov. 27
Nov. 30
Dec. 7
Dec. 11
Dec. 14
Dec. 19
Dec. 21
Dec. 26
Dec. 29
Dec. 31
1973
Jan. 1
Jan. 2
Jan. 5
Jan. 8
Jan. 11
Jan. 15
Jan. 18
Day of
Year
262
267
271
282
287
292
298
303
319
322
331
334
341
345
348
353
355
360
363
365
1
2
5
8
11
15
18
NH3
(mg/1)
0.3
0.3
0.3
0.8
1.8
1.7
3.5
3.6
1.5
0.2
0.4
1.6
0.9
1.6
1.2
2.1
2.1
2.3
2.4
2.8
3.0
3.1
5.7
6.0
Date
Jan. 22
Jan. 25
Jan. 29
Feb. 1
Feb. 5
Feb. 8
Feb. 12
Feb. 15
Feb. 19
Feb. 22
Feb. 26
Feb. 28
Mar. 16
May 24
May 31
June 7
June 14
June 21
June 28
JulyS
July 12
July 19
July 25
Aug. 2
Aug. 16
Aug. 23
Day of
Year
22
25
29
32
36
39
43
46
50
53
57
59
75
144
151
158
165
172
179
186
193
200
206
214
228
235
NHo
(mg/1)
7.4
9.0
10.8
11.1
8.5
10.1
10.6
10.1
9.8
9.6
11.1
10.4
9.6
0.4
0.5
0.1
0.4
0.3
0.3
0.3
0.3
0.2
0.2
0.2
0.2
0.2
Disinfection
Chlorination of lagoon effluent both during
discharge to the river and when irrigating is a regular
established practice. Facilities consist of gas chlori-
nators discharging through diffusers installed at the
entrance to a baffled chlorine contact tank. Control
of chlorine feed is exercised so as to maintain a
chlorine residual (total combined chlorine by OT
method) of as close to 0.5 mg/1 as possible. Records
indicate that this has been done effectively most of
the time with little difficulty.
As shown in Tables 3 and 4, these practices
usually have been effective in destruction of total
coli. Other data at the on-site laboratory indicate that
there are seldom any fecal coli found in these
chlorinated wastes.
Chlorination at Continuous Discharge
Stabilization Lagoons
The July 1, 1974, printout of the EPA data
bank (STPOM forms 5 and 12) identify nearly 100
municipal installations with Chlorination facilities at
raw waste stabilization lagoons. The majority of these
use gas type chlorinators with chlorine introduced at
the point where the lagoon effluent enters a chlorine
contact tank as it is being discharged for final
disposal. It is discouraging and quite revealing to note
that only seven of these are reported as recording
chlorine residuals after the contact period and only
four perform bacteriological analysis, two for fecal
coli and two for total coli. It is expected, of course,
that most if not all of these municipalities will soon
be performing such tests to meet EPA regulations and
NPDES requirements.
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 129
This investigator made a search of the technical
literature and talked with program directors in many
states, attempting to locate and obtain useful, reliable
information on lagoon effluent disinfection practice.
The paucity of available data of this kind confirms
that only a few municipalities in the nation perform
sufficient laboratory tests of this nature to provide a
basis either for control of the process or a reliable
indication of what is actually being achieved in
bacterial control.
In many of the states there are few if any
installations depending on effluent chlorination for
bacterial control. Rather the natural process of
die-off during long period storage under conditions
prevailing in the lagoon are depended upon for this
purpose. It is clear, however, that under many
circumstances of high loading, short residence time
and unfavorable climatic conditions, high concen-
trations of fecal coli have been found and can be
expected to be present in the lagoon discharge.
It is of interest, therefore, to examine the data
available on effluent disinfection practice and results.
As indicated herein the City of Belding, Michi-
gan, has established an effective method of disin-
fecting, with chlorine, effluents discharged from a
system of five lagoons operated in series after long
period storage. No data are available at this location
for short period storage or continuous discharge.
Chesterfield Township studies
The City of Detroit operates a raw waste
stabilization lagoon facility serving limited residential
areas in Chesterfield Township, Macomb County.
This facility is designed and operated for continuous
discharge with effluent disinfection. There are three
lagoons each of about equal size with a total area of
about 70 acres. Water depth is maintained constantly
at about 6 feet.
Raw wastewater is delivered to the lagoon site
by force main from a remote site. Daily flows
fluctuate between 0.5 mgd and 2.0 mgd, influenced
by infiltration and inflow to the sewer system. The
wastes are directed through the three cells in series,
then flow by gravity through a chlorine contact tank
after initial mixing with chlorine from two 1-ton
cylinders. Chlorine is usually fed at a constant 90 Ib
per day rate. Chlorine residuals after 5 minutes
contact are always at least 1.0 mg/1 and usually
higher.
Alum is fed into the pipe connecting Cells 2
and 3 at a constant rate of 6& gallons per hour (55
mg/1 A12S04). This is found to assist materially in
clarification of the contents of the final cell.
Samples of the effluent are collected twice
daily for chemical and bacterial analyses and chlorine
residuals are determined on each sample. The data
reported by the City of Detroit wastewater treatment
plant operations staff are summarized in Table 6.
Table 6. Effluent quality 3-cell continuous flow lagoons, Detroit (Chesterfield Twp.), Michigan, January 1973
May 1974.
Month
1973
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
1974
Jan.
Feb.
Mar.
Apr.
Mav
PH
6.5-6.8
6.7
6.2-8.4
7.7-8.7
8.1-9.0
7.8-8.6
7.0-8.3
7.4-8.5
7.9-8.6
7.3-7.9
7.6-7.9
7.8-8.2
7.6-8.1
6.8-7.5
7.7-8.5
7.2-8.1
7.5-8.7
BOD5 (n
Range
1-9
3-13
5-14
2-7
2-24
4-26
2-16
1-21
0-19
0-16
0-11
1-4
1-8
5-36
3-29
1-4
1-13
Avg.
4
9
10
4
10
16
11
5
4
4
2
2
2
19
9
2
1
Susp. Solids
Range
11-82
17-124
10-200
18-126
8-50
14-102
1949
5-68
3-83
2-38
4-29
3-47
4-19
9-82
8-36
15-66
13-58
(mg/1)
Avg.
34
35
68
47
31
61
47
31
34
15
11
14
7
39
21
35
41
Total P
mg/1
2.8-6.0
5.2-8.4
5.5-7.2
3.4-6.1
3.0-6.9
3.24.8
1.54.1
1.6-3.0
0.5-2.5
2.2-6.3
1.6-2.9
2.74.5
4.2-6.7
1.9-6.3
3.0-7.6
1.7-3.1
1.6-2.8
Fecal Coli
per 100 mis
<23-230
<23
<23
<23
<23
<23
<23
<23
<23
<23
<23
<23
<23-11000
23-2300
<23-730
<23
<23
-------
130
Pierce
No reliable data are available on fecal coli
concentrations of lagoon effluents prior to disin-
fection although spot samples taken from time to
time indicate that concentration is variable, ranging
from less than 10 to over 1000 per 100 mis.
The effluent samples are routinely tested for
total phosphorus. Concentrations range generally
from 1.5 to 6.0 mg/1 as P. No data are available on
phosphorus levels in the raw waste.
Illinois studies
The Illinois Environmental Protection Agency
assembled information for this report from their data
printout system on nine municipal waste stabilization
lagoons with chlorinated effluents. All of these
systems are of the continuous flow-through type.
Present loadings are 90-105 persons per acre (total
acreage) except for facility No. 4 which had about
160 persons per acre when sampled. This facility has
relatively small volume and surface area in Cells 2 and
3.
Samples are collected and analyzed by the
agency. Results are summarized in Table 7.
No information is available at this writing on
the type of chlorination facilities, chlorine feeding,
and mixing and contact tanks, nor is there infor-
mation on chlorine feed control related to chlorine
residual levels and coliform concentrations. Such data
are needed to determine the capability of the
facilities to achieve low fecal coli levels dependably.
The BOD5, suspended solids concentrations are
generally a bit higher than noted for the long period
storage and controlled discharge lagoons reported
here but ammonia and nitrate levels are very similar
to these. Here again high ammonia levels were
associated with cold weather and lowest levels with
summer temperatures.
Chlorination of Lagoon Contents
A small residential subdivision known as Red
Oaks of Chemung is served by a wastewater treatment
system consisting of 2-cell lagoons followed by spray
irrigation. The facilities are operated by the County
Department of Public Works.
The two cells are operated in series. All raw
wastewater is delivered to Cell No. 1 and transferred
by pumping to Cell No. 2 where the contents are
isolated for several weeks before chlorination of the
total liquid surface area prior to release for spray
irrigation.
The following procedure, established by the
consulting engineer who designed the facilities, is
utilized by operating personnel to assure effective
disinfection.
Irrigation from the north lagoon shall not
be carried out until the following chlorination
procedures have been accomplished. Twenty-
four hours prior to irrigation an application of
at least 8 mg/1 of available chlorine shall be
applied to the lagoon. The application shall be
as evenly distributed as possible by broad-
casting. Two hours before irrigation a second
application of at least 2 mg/1 of available
chlorine shall be similarly accomplished. Just
prior to each chlorine application at least two
samples shall be collected and a dissolved
oxygen test accomplished with the results being
recorded on the data forms. Before pumping to
irrigation a sample shall be collected and
analzyed for a free chlorine residual-no spray-
ing shall be accomplished unless a substantial
chlorine residual is displayed and duly re-
corded. These chlorine tests shall be conducted
at least twice during the period of pumping to
determine that a chlorine residual is being
maintained. If no residual can be detected,
spraying shall be halted.
When a chlorine residual has been esta-
blished and maintained, with additional spray-
Table 7. Summary by Illinois EPA analysis of results from nine municipal waste stabilization lagoons with
chlorinated effluents.
Facility
No.
1
2
3
4
5
6
7
8
9
No.
Samples
7
8
2
6
9
7
3
9
3
BOD5I
Range
1-37
4-27
13-27
18-50
1-38
15-45
0-25
12-46
9-33
Avg.
8
19
21
35
9
25
12
23
21
Susp.Sol.(mg/I) NH3-N
Range Avg. Range
4-74
6-80
11-35
70-160
1-19
13-88
1-58
3-66
22-92
26
45
26
105
8
60
25
38
54
0.7-7.0
0.2-1.2
0.4-1.8
0.3-3.1
0.1-5.9
0.2-8.3
0.2-7.1
0.2-3.0
0.3-2.5
(mg/1)
Avg.
2.1
0.5
1.1
1.0
1.0
2.7
2.5
0.9
1.0
NO3-N (mg/1)
Range Avg.
0-0.3
0-0.8
0.1-0.7
0-0.5
0-0.6
0-1.0
0.2-0.3
..
0-1.9
0.1
0.2
0.4
0.2
0.1
0.3
0.2
..
0.6
Fecal Col. (MPN)
p Geom.
Ran8B Mean
100-600
100-1700
0-100
100-3400
10-30000
10-1000
50-100
0-1300
0-140
184
237
10
546
272
116
62
19
5
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 131
ing contemplated foi the following day, the 24
hour prior application of 8 mg/1 wfll not be
essential. However, the two hour prior 2 mg/1
application shall be accomplished.
Chlorine applications shall be in accord
with the water level in the lagoon and the
computed quantities tabulated below.
Founds Chlorine
Required
Pounds Chlorine
Required
Liquid Volume 2 mg/1 40% 70% 8 mg/1 40% 70%
Depth in gals. Appli. Pow. Pow. AppU. Pow. Pow_
in Feet x 1,000 cation der der cation der der
1
2
3
4
5
6
7
8
9
255
530
825
1,143
1,485
1,852
2,244
2,662
3,107
4
9
13
18
24
30
36
42
50
10
21
33
46
60
74
90
107
124
6
12
19
26
34
42
51
61
71
16
34
53
73
95
119
144
170
199
41
85
132
183
238
296
359
426
497
23
48
75
105
136
169
205
243
284
The hypochlorite powder is distributed man-
ually with a rotary-type fertilizer spreader mounted
in a row boat. One man cranks the spreader while
another rows the boat back and forth until the entire
surface has been well covered.
Samples for bacterial analyses are collected by
the public works staff and sent to the state labora-
tories by sample mailers. Fifty-seven samples were
analyzed for total and fecal coli, 31 of which were
collected mornings, and 26 during afternoons on 31
days during irrigation periods. Total coli concen-
trations ranged widely from a few thousand to a few
hundred thousand with a geometric mean of 8984.
On the other hand fecal coli levels were less than 10
per 100 mis for SO of the 57 samples with a
geometric mean of about 10.
This appears to be a most effective method of
disinfection for small installations.
Lagoons Following Secondary Treatment
One hundred and ten lagoons following trick-
ling filters and activated sludge plants are recorded in
the July 1 EPA data bank printout of facilities in the
federal grant program. It is to be expected that many
more such facilities will be constructed to meet
present and future effluent requirements. It is useful,
therefore, to examine the great wealth of information
generated in the study of performance of lagoons
following trickling filters at the State Prison of
Southern Michigan.
State Prison of Southern Michigan
The treatment works serving the prison were
built in the late 1930's and have continued in service
without major modifications until polishing lagoons
were installed in 1968 to meet more stringent
requirements for discharge to a critically oxygen-
deficient stream receiving wastes from this and other
sources including the City of Jackson.
Facilities
Raw wastes enter old Imhoff Tanks after
screening arid grit removal, thence to trickling filters
from which the effluent is discharged to a 2-cell
lagoon normally operated in series. A yearly manage-
ment pattern of storage in and discharge from the
lagoons is utilized for controlled release to the Grand
River when flows and dissolved oxygen in the river
are relatively high and lagoon quality is optimum. In
a typical year storage without discharge begins in May
as river flow decreases and continues until about
November when lagoon contents are lowered in series
from about 10-foot depth to about 3 feet. When
water levels reach 10 feet again in December, the
lagoons are discharged in series under ice cover until
some time in April after ice has thawed when water
levels are again lowered to about 3 feet and made
ready for summer storage.
At the 10-foot operating level with cells in
series residence time at 1.1 mgd flow is about 120
days.
No aeration is provided. Wastes are not chlori-
nated at any point in the process.
Performance
The following data (Table 8) are taken from
operation reports submitted each month to the state
regulatory agency by the certified plant super-
intendent. Observations and laboratory testing of a
very thorough and varied nature are made daily
throughout the year by the operating staff.
During summer months ammonia nitrogen con-
centrations are typically around 0.5 mg/1 as N, rising
to about 2.0 with coldest water temperatures.
Analyses are made routinely for total coli in the
lagoon effluent or near the point of discharge.
Generally concentrations are very low. A large per-
centage of tests were registered as zero and seldom
exceeded 200 per 100 mis. During four days in
September and five in October the report indicates
TNTC (too numerous to count).
-------
132 Pierce
Table 8. Performance data of lagoons following trickling filters at State Prison of Southern Michigan at Jackson.
Item
Period
December 1971
Daily Range Mo. Avg.
Period
Year 1971
Monthly Range Ann. Avg.
Raw Flow (mgd)
BOD5 (mg/1)
Raw
T.F. Eff.
Lagoon Eff.
Susp. Sol. (mg/1)
Raw
T.F. Eff.
Lagoon Eff.
PH
Raw
Lagoon Eff.
Total Phosphorus
(mg/1 as P)
Raw
T.F. Eff.
Lagoon
NH3-N (mg/1)
Raw
T. F. Eff.
Lagoon Eff.
0.9-1.2
145-340
13-34
4-11
160-248
24-50
16-42
7.1-7.4
4.5-8.7
4.3-6.0
0.8-2.3
10-19
3.5-7.0
0.6-2.1
1.06
228
22
8
183
34
29
7.2
8.4
6.5
5.4
1.8
13.6
5.3
1.1
1.04-1.22
156-237
13-22
4-22
164-184
34-48
18-93
7.0-7.2
7.9-9.8
4.8-7.2
3.6-5.7
0.1-2.5
9.1-13.7
2.8-5.3
0.2-1.8
1.11
200
17
11
176
38
43
7.1
8.8
5.8
4.6
1.1
10.9
4.1
0.8
Fargo, North Dakota
Another example of lagoons installed to supple-
ment treatment provided by trickling filters are those
completed by the City of Fargo a year or so ago to
meet elevated effluent requirements for discharge to
the Red River of the North.
Facilities
Raw wastewater averaging 5-6 mgd, collected
by the municipal sewer system, passes through a
screening chamber, primary settling tanks, and two
trickling filters, one with stationary nozzles, the other
with rotary distributors, followed by final settling
tanks. Sludge digestion facilities complete the mechani-
cal plant portion now in use. Chlorination facilities
customarily used in the past have not been used since
the lagoons were placed in operation last fall. The
wastes from the plant are pumped some 4 miles to
the lagoon site which occupies one square mile.
Lagoons consist of five cells, four of which are used
as primary and secondary units on a selective basis
and the fifth, deeper than the others is used as the
final polishing unit prior to discharge.
Performance
The final cell normally is filled and isolated
with no inflow for several weeks before the contents
are released. Storage takes place through the long
winter months without discharge. When the quality
of the contents of Cell No. 5 are favorable for dis-
charge in the spring, the cells are progressively lower-
ed. This process continues through summer and fall,
drawing all cells down to lowest level consistent with
good effluent quality before the onset of winter
weather.
Effluent quality is typically as follows:
Trickling filter plant
BODJ5 30 • 40 mg/1 - mid-spring to mid-fall
60 • 70 mg/1 - cold weather
Suspended solids - A little higher than BOD
Lagoons
BOD5 10-15 mg/1, sometimes less
Suspended solids -10 - 20 mg/1 usually
Fecal coli < 100 per 100 mis consistently
Aerated Lagoons
The EPA data bank on facilities constructed or
proposed has record of 137 aerated lagoons as of My
1, 1974. These vary widely in construction features
and loadings and are designed to achieve a rather wide
range of effluent quality, either by themselves or in
combination with other treatment units.
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 133
Reed City, Michigan
A quite typical installation of this kind has
been in operation at Reed City, Michigan, since late
1971. These facilities were selected for study because
they typify the rather common circumstance of a
small community with a large but fluctuating organic
loading from industry where the treated wastes
discharge to a quite limited stream resource, requiring
a high quality effluent low in oxygen consuming
substances, nutrients, and coliforms. Industrial wastes
consist of 3040,000 gals/day of rinse water following
withdrawal of strong whey in cottage cheese manu-
facturing plant. BOD5 of these wastes ranges from
3000-4000 mg/1. The mixed wastes have BOD,
averaging about 350 mg/1 and total suspended solids
averaging about 160 mg/1.
Facilities
Raw wastes are discharged to three 1-acre
aerated lagoons approximately 10 feet deep (opera-
ting depth) equipped with 45,000 feet of perforated
piping (Hinde System). Lagoons are operated in
series. Residence time in each cell at present loadings
is about 10 days.
The lagoon effluent is returned to the old plant
site for phosphorus removal and disinfection.
Chemicals (lime or alum) are added in a rapid mix
chamber, thence to a flocculation chamber where a
polymer is added prior to discharge to the old
sedimentation tanks. Chlorine is applied by semi-
automatic gas chlorinators to the settled effluent
prior to entering the old baffled chlorine contact tank
Table 9. Performance data of aerated lagoons followed by chemical precipitation, sedimentation, and chlo-
rination at Reed City, Michigan.
10-25 minutes time of passage at present flow rates.
30004000 gallons of chemical sludges are withdrawn
daily from the sedimentation tanks to a small sealed
earthen lagoon and periodically removed for land
disposal.
Performance
The data in Table 9, extracted from the October
1972 and June 1973 monthly operation reports
submitted by the certified operator to the state
regulatory agency, are typical of loadings, chemical
dosages and effluent quality during 1972 and the
present time.
It is of interest to compare these results with
performance of the original primary plant which
consisted of grit removal, screening, plain sedi-
mentation tanks, chlorination and heated sludge
digesters. The operation report for September 1971
provides data for these facilities.
Item
Flow (mgd)
BODS
Raw
Eff.
Suspended Solids
Raw
Eff.
Chlorination
C12 feed (Ibs/day)
Residual (mg/1)
Coli, total per 100 mis
Range Mean
0.23-0.31 0.28
250-1120 557
150400 304
150-322 215
72-180 134
88-123 105
16-30
0-1500
Item
October 1972
June 1973
Range
Mean
Range
Mean
Flow (mgd)
Raw
Eff.
BOD5 (mg/1)
Raw
Eff.
Suspended Solids (mg/1)
Raw
Eff.
Total Phosphorus (P) in mg/1
Raw
Lagoon Eff.
Eff.
Chlorination
C12 feed (Ibs/day)
Residual (mg/1)
Coli, total (per 100 mis)
0.20-0.30
0.18-0.34
160-600
1-6
126-206
6-36
10-21
13.5-15.5
1.3-5.6
5-9
0.4-1.0
0-7.3
0.24
0.26
408
3
163
18
18
14.3
2.4
6.7
0.28-0.37
0.28-0.47
100460
1-13
110-186
7-25
6-17
12-13.5
2.6-12.2
8-17
0.8-1.5
443
0.33
0.35
306
8
159
17
13
13
6.7
13
-------
134
Pierce
Operational control
The treatment facilities and laboratory analyses
are under the control of the same certified operator
who capably operated the primary plant before,
during and after construction of the modifications
and additions. He has one assistant operator. Between
them they manage the facilities 7 days a week. Some
indication of the continuity of control is the recorded
data for chlorination. At least 6 readings, usually 8,
between 7 a.m. and 5 p.m. are taken daily on rate of
treated waste flow and chlorine feed rate and chlorine
residuals are determined for each reading. Chemical
analyses are made, usually 4 days per week, and many
physical measurements and observations are recorded
daily. Operators perform all maintenance and are
intimately familiar with all equipment and process
control measures. When questioned about attendance
on Saturday and Sunday the certified operator said,
"It's no different than managing a dairy herd. You've
got to milk them twice everyday."
Observations and Conclusions
1. Long period storage and controlled dis-
charge. Study of the history of performance of raw
waste stabilization lagoons with an effective discharge
control program involving long period storage and
seasonal discharge, including over 40 installations in
Minnesota and many in North Dakota, confirm the
observation made last year on the study of 49
Michigan installations of this kind that: (1) Such
lagoons can consistently produce effluents meeting
EPA requirements for secondary treatment for BOD,
and fecal coli and generally can meet the suspended
solids requirement when loadings are in the 100
persons per acre range, and (2) fecal coli requirements
of 200 and 400 per 100 mis cannot be met with such
facilities during winter ice cover and when water
temperatures approach freezing temperatures. Again
no data were available on performance of these
facilities at loadings above 20-25 pounds of BOD, per
acre per day (based on total acreage) or short
retention periods.
2. Continuous flow systems. Nine continuous
flow lagoons in Illinois with system loadings in the
100 person per acre range generally met the EPA sec-
ondary treatment requirements for BOD and sus-
pended solids.
3. Nitrification. Studies of a 5-cell lagoon sys-
tem at Belding demonstrated a high degree of nitri-
fication in the first three cells with ammonia nitrogen
falling from some 20-30 mg/1 in the raw waste to less
than 1 mg/1 in mid-summer but with practically no
nitrification during winter months. Ammonia levels in
the effluent fell in late spring and rose in early fall in
a cyclic fashion. Similar results were found at nine
typical continuous discharge lagoons in Illinois which
were selected for study by reason of their data on
effluent disinfection. This temperature relationship
was found in lesser degree at the State Prison of
Southern Michigan at Jackson where a 2-cell lagoon
system with controlled discharge is used to improve a
trickling filter effluent. Here ammonia concentrations
of around 0.5 mg/1 as N rise to about 2.0 mg/1 during
winter discharge.
4. Chlorination for disinfection. Little informa-
tion could be found on fecal coli concentrations
following disinfection of the lagoon effluent with
chlorine although over 100 such installations are
recorded in EPA's O&M file of facilities inspected.
Data from the nine continuous flow lagoons in
Illinois indicated fecal coli levels approaching the
required 200 per 100 ml standard but with a fair
percentage considerably higher. More study of
facilities of this kind is needed to determine what can
be achieved in such installations. Chlorination of the
effluent from a 3-cell continuous flow lagoon
operated by the City of Detroit with chlorine residual
levels consistently above 1 mg/1 produced a high
degree of kill. Fecal coli concentrations were nearly
always less than 23 per 100 mis. Excellent results
were obtained also from the 5-cell controlled dis-
charge lagoon at Belding, Michigan, with chlorine
residual concentrations consistently around 0.5 mg/1
after a 10-25 minute contact period.
5. Lagoons following trickling filters. Several
years of good records at the Southern Prison of
Michigan with two-stage lagoons with up to 4 months
residence time following standard rate trickling filters
document effluents have BODs usually less than 10
mg/1, total phosphorus under 2 mg/1 most of the year,
a high degree of nitrification during warm weather
and very low fecal cob* concentrations. Results at a
similar quite new installation at Fargo, North Dakota,
indicate promise of similar performance.
6. Aerated lagoons. An aerated lagoon fol-
lowed by chemical flocculation for phosphorus re-
moval at Reed City, Michigan, routinely produces an
effluent with BOD5 less than 10 mg/1 and suspended
solids under 20 mg/1. Fecal coli in the effluent are
consistently under 50 per 100 mis with low chlorine
feed rates and chlorine residuals of 0.5 to 1.5 mg/1.
7. Number of cells required. In our study of
performance of 49 raw waste stabilization lagoons
last fall it was observed that little difference could be
detected in the quality of effluent from 2-cell
compared with 3-cell systems. It was noted also that
all of the systems studied were either at or below the
design loading of 20 pounds BOD5 per acre per day
or 100 persons per acre. Generally, these facilities
receive more attention and are more effectively
-------
Performance of Raw Waste Stabilization Lagoons in Michigan 135
operated by specially trained public works personnel
than usually found elsewhere. Discharge occurs only
after long period storage and usually after a period of
several days or weeks of isolation of the discharging
cell. It was further noted that nearly all of the 49
systems were relatively young, having been in opera-
tion for 2 to 5 years and some even less.
Each of these factors provide some increase in
the chance that the effluent from a second cell be of
good quality. It is reasonable to expect, however, that
over a longer period of time the greater flexibility
afforded by a third cell will increase the capability of
the system to operate continuously at a high level of
effectiveness. The value of the third cell will be
greatly increased with provision for parallel or series
operation so that the wastes may be routed into or
out of any of the three cells. Experience throughout
the country clearly indicates that any one of the cells
may require isolation, drawdown for repairs or special
maintenance, often requiring long periods to correct
the problem. For these reasons many of the states
have adopted standards or guidelines calling for a
minimum of three cells for raw waste stabilization
lagoons, a decision well founded on practical con-
siderations.
8. These studies indicate that various types of
lagoon faculties with conservative loadings and effec-
tive operational control are producing effluents which
meet secondary treatment requirements and hold
promise of a high degree of nitrification and other
evidences of a high quality effluent. It is to be
expected that improved operational controls includ-
ing regular laboratory analyses will greatly improve
the performance of a high percentage of lagoons now
in use, at the same time providing a firmer base for
design of facilities for the future.
-------
SEPARATION OF ALGAE CELLS FROM WASTEWATER
LAGOON EFFLUENTS BY SOIL MANTLE TREATMENT
R. A. Gearheart and E. J. Middlebrooks1
Soil Mantle Disposal of
Lagoon Effluent
A review of the history of sewage treatment
indicates that wastewater irrigation was originally
developed in the early nineteenth century as a system
of both treatment and disposal (Rafter, 1897;
Rudolfs and Cleary, 1933; Mitchell, 1931). In recent
years, other forms of waste treatment have become
popular. The growth of technical knowledge has led
to a reexamination of the possibilities of treatment
and disposal of certain industrial, agricultural, and
domestic wastewaters through the application of
irrigation techniques (Riney, 1928; Mitchell, 1930;
Goudey, 1931; McQueen, 1934;DeTurk, 1935). Thus
the cycle has run its course, the earliest form of waste
treatment is now the subject of research and develop-
ment for the disposal of the water of our time
(Skulte, 1956; Dye, 1958; Henry et al., 1954; Hunt,
1954;Warrington, 1952; Wells, 1961).
However, irrigation with wastewater is not a
panacea for the economical treatment and disposal of
wastes. Sanitary, aesthetic, economic, ecological, and
other technical and practical considerations must be
carefully balanced for a sound wastewater irrigation
system.
The effect of sewage effluent on the yield of
agronomic crops has, in most cases, been found to be
beneficial (Hill et al., 1964; Herzik, 1956; Merz,
1956; Wilcox, 1949). Feinmesser (1970) obtained a
significant increase in the yield of reed canary grass.
Huekelekean (1957) obtained excellent crop yields in
Israel. Stokes et al. (1930) obtained yield increases in
Florida amounting to 240 percent for both Napier
grass and Japanese cane, when compared with the
unirrigated crops, or with the same crops irrigated
with well water. Day and Tucker (1960a, 1960b) and
Day et al. (1962) in Arizona, obtained beneficial
yield effects on small grains which were harvested as
pasture forage, as hay or as grain. Parizek et al.
lR. A. Gearheart is Associate Professor, Division of
Environmental Engineering, and E. J. Middlebrooks is Dean,
College of Engineering, Utah State University, Logan, Utah.
(1967) at Penn State, have extensively explored the
use of wastewater as a spray irrigant on forestry land.
More than 100 kinds of viruses are known to be
excreted by man and approximately 70 of these have
been found in sewage (Clark and Chang, 1962). Those
that appear to be transmitted through wastewaters
are the entero-viruses, poliomyelitis (Paul and Trask,
1942a, 1942b; Little, 1954;Kelley, 1957; Bancroft et
al., 1957), coxsachie (Clark, 1971) and infectious
hepatitis (Hayward, 1946; Dennis, 1959; Yogt,
1961). There are a limited number of studies of the
movement of viruses through granular media (Merrell,
1963). These studies showed that rapid sand filtration
preceded by coagulation and sedimentation only
partially remove virus. The removal of virus from
percolating water is largely due to sorption on the soil
particles. Soils having a higher clay content sorbed
virus more rapidly than those with less clay (Eliassen
etal., 1967).
The soil system is composed of gas, water
microorganisms, minerals, and organic matter which
form the solid matrix. Experience has indicated that
this dynamic system is constantly undergoing
physical, chemical, and biochemical interactions.
Wastewater applied to the soil mixes with the existing
soil water, becoming a part of the system, and may
alter the nature and rate of change of the physical,
chemical, and biochemical processes in the soil
system.
Many insoluble constituents such as suspended
minerals, participate organics, and inorganic precipita-
tes are quickly removed from the liquid by the
surface area of the soil. Some of these substances are
altered, but some become a permanent part of the
soil. Irrigation with wastewaters may produce bene-
ficial or detrimental changes in the soil system.
Physical clogging of the soil pores and the
resulting loss in the infiltration rate have caused many
wastewater soil treatment systems to fail (Avnimelech
and Nevo, 1964; Jones and Taylor, 1965; Mitchell
and Nevo, 1964; Winneberger et al., 1960; Thomas et
al., 1966; Amramy, 1961). The political hazard of
high sodium rates to the physical properties of certain
soils is of paramount concern. This phenomenon has
137
-------
138 Gearheart and Middlebrooks
been studied extensively for the improvement of
saline and alkali soils by the proper management of
irrigation practices (U.S. Salinity Laboratory, 1954).
It is well known that additions of organic matter
improve the aggregate stability of soils, and waste-
waters high in organics have been used to improve the
physical properties of soils (Merz, 1959).
It has been known for years that organic matter
serves as a granulating agent in soils. Bauer (1959)
showed that organic matter is conducive to the
formation of relatively large stable aggregates and
that the effect of organic matter is more pronounced
in soils containing small amounts of clay. Small
amounts of added organic matter appear to promote
large stable aggretages of clay, silt, and sand. The
organic content of oxidation pond effluent, both
dissolved and particulate (algae) may therefore have a
beneficial effect on the soil permeability. Soil micro-
organisms undoubtedly play a major role in pro-
ducing organic cementing materials. Martin and
Waksman (1940) observed that the growth of micro-
organisms led to the binding of soil particles, and the
more readily the substrate on which the micro-
organisms bred decomposed, the greater the effect on
aggregation. Plant roots appear to be very effective in
promoting aggregation by soils. The unusual aggre-
gation of soils in the roots of plants probably is the
consequence of mechanical disturbance by plant
roots and by wetting and drying, together with
cementation by organic compounds (Jenny and Gros-
senbecker, 1963). The efficiency of spray irrigation
of vegetated areas for wastewater disposal is un-
doubtedly due in part to enhancement of permeable
structures by plant roots.
Filtration is important for removing suspended
particles from wastewater effluents penetrating the
soils and for retaining the microorganisms that
facilitate biological decomposition of dissolved and
suspended organic matter. Even though the removal
of suspended particles from water flowing through
soils is easily observed, the processes involved are
difficult to describe in simple cases. Listed below are
three of the simplest mechanisms which might be
combined to describe more complex situations.
Case I—Straining at the soil surface. Under
these conditions the suspended particles
accumulate on the soil surface and be-
come a part of the filter.
Case II—Bridging. Under these conditions sus-
pended particles penetrate the soil surface
until they reach a pore opening that stops
their passage.
Case III—Straining and sedimentation. This
includes all of the conditions for Case I
and Case II except that the suspended
particles are finer than half of the
smallest pore openings.
Irrigation with wastewater has a marked in-
fluence on the chemical equilibria in the soil. Organic
matter and clay added in the suspended solids can
increase the cation exchange capacity of the soil
(Ramati and Mor, 1966). Many of the dissolved
chemicals in wastewater influence the suitability of
the soil for crop production. Nitrogen and phos-
phorus compounds have a beneficial fertilizer value
when retained in the soil and utilized by the crops.
Pollution of groundwater by nitrates which move
freely in the soil can be a serious problem (Ground-
water Contamination, 1961; Stewart, 1967). Release
of phosphorus from soils to our surface waters can
also contribute to pollution (Taylor, 1967). Boron
content has caused concern in areas where boron-
sensitive crops are irrigated with wastewater (State
Water Pollution Board of California, 1955). Toxic
concentrations of copper and zinc have apparently
accumulated in the soil at sewage farms (Rohde,
1962).
The application of soil mantle disposal to
upgrading lagoon effluent is limited by soil and
groundwater characteristics. However, most lagoons
are constructed in areas where land is available and
thus capital investment for land mantle disposal is
relatively low. Further, soil mantle disposal does not
create a sludge disposal problem, has a low main-
tenance and operation cost, and may provide addi-
tional irrigation water in arid regions. Therefore, it is
felt that soil mantle disposal may be of practical value
in upgrading lagoon effluent.
Soil Mantle Disposal
Experimental Design
The experimental design for use of the soil
mantle as an algal cell removal process consists of
several interacting processes. The first rationale for a
process would be that the soil mantle system would
essentially be used as a storage compartment for the
effluent. There would be no surface runoff or
groundwater movement of the effluent. Evaporation
from the soil, hydraulic conductivity, and lateral
dispersion would determine the storage capacity of
the soil. This process would have several severe
disadvantages, such as seasonal variation in soil
moisture storage potential, large volume of soil
necessary, and extensive drainage and surface leveling
to minimize runoff and groundwater implication.
Another process design would be to consider
the water requirements of the vegetation being irri-
gated and the possible removal of the algal cells by
impaction and impingement of the cells on the plants.
-------
Oxidation Pond Effluent ~
Water Demand
Utah Soil Types
Climatological
Cons ide ra t i ons
*• Forage Crops
Public Health Aspects
Storage
Cons iderat ions
t
±
Nozzle Configuration
Soil
Column
Pilot
Chemical
Physical
Biological
Return Flow
Characteristic
Constraints
For Waste Treatment
Systems
System
Design
Concepts
Organic
Loading
Nutrient
Loading
Hydraulic
Loading
Ion Exchange
Capacity
Bacteria And
Virus Dieoff
Field Test
With
Typical
Crops
Validation
Production
Of
Forage
Crops
Return Flow
Characteristic
Cost Of Waste
Treatment System
Value Of
Forage Crops
f
I
I
I
Figure 1. Information flow chart for the research project.
<*>
SO
-------
140 Gearheart and Middlebrooks
THEORETICAL ASPECTS
TREATMENT SYSTEM
DESIGN CRITERIA
Single cells
Colony of cells
Auto-flocculation
Other suspended solids
Cell lysing
Release of cellular
constituents
Cellular deposition
ALGAL CELL SOURCES
TRANSPORTATION
IRRIGATION PIPELINES
I
Cell lysing
Release of volatile
constituents
Evaporation
Reaeration
SOIL MANTLE
DISTRIBUTION SYSTEM
SPRAY NOZZLE
Size of algal cells
Concentration of algal cells
Seasonal variation
Temperature
Storage consideration
Pumping consideration
non-clog pump
Distance to be pumped
Frequency of pumping
Orifice clogging
Spray pattern
Uniformity coefficient
Nozzle pressure
Nozzle flow rate
Physical clogging
Physical degradation
Chemical degradation
Soil storage
Gass transfer
Ion exchange capacity
SOIL MANTLE
TREATMENT
SYSTEM
Infiltration rate
Soil texture
Surface drainage
Soil chemistry
SOIL MANTLE
RETURN FLOW
Biodegradation by-products
Water Quality Standard
Flow
Storage
RELEASE TO
SURFACE OR
SUBSURFACE
Figure 2. Soil mantle.
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 141
The root zone depth could be the level of intermittent
saturation required to satisfy the plants. This process
design has several limitations also, one being the sea-
sonal productivity and the amount of water necessary
for optimum plant growth.
A third process design could be envisioned that
would incorporate the advantages of two previously
mentioned systems. Soil moisture storage as well as
vegetation water requirements could be considered on
a seasonal basis. During the non-productivity period
of the year, the soil mantle system could be loaded to
maximum soil moisture conditions while during the
growing season the water requirement of the vegeta-
tion controls the rate of application. A storage
capacity of 120 days would suffice for cold weather
operations where ground conditions would not allow
irrigation.
The soil only system would develop infor-
mation typical of spring and fall spray irrigation of
oxidation pond effluent. Meaningful data concerning
soil moisture and storage capacity in terms of
application rates and cell removal could be developed.
The vegetation plot would allow an analysis of the
transpiration rates and the effect of plants on the
filtering phenomena of algal cells, such as im-
pingement, impaction, etc.
Soil mantle facility
The Utah State University reclamation farm
(110 acres) is located approximately in the center of
Cache Valley, where the land is essentially flat. The
slope is actually 0.07 percent to the west. Most any
type of irrigation system can be used without
expensive leveling. Much of the land in this area
contains humics which makes efficient farming ex-
tremely difficult. Fortunately only about 3 acres are
classed as humicy on the reclamation farm.
The top soil over most of the farm is extremely
thin (1 to 2 feet). The texture of this material is
mainly silty clay loam. Below this top soil is a tight
impermeable clay which may be gleyed or mottled
depending on the location on the farm. A soil survey
has been conducted on the reclamation farm by
drilling 34 test holes cored to a depth of 11 to 12
feet. The majority of the soil is clay with silty clay,
and silty-clay-loam within the surface 2 to 3 feet.
Most of the clay is tight and mottled or gleyed. A
stratified sand, silty clay layer can be found under
most of the farm at a depth of from 10 to 12 feet.
This material may be helpful in removing the water
coming up from the aquifer and down from the
surface.
An open drain exists on the reclamation farm
to remove surface water and some groundwater.
During the winter and spring months the drain carries
off about 3 second feet, helping drain the surface of
about 400 acres on the immediate area of the farm.
Experimental design
The experimental design will consist of eight 50
x 50 foot test plots irrigated at three different rates
(2, 7, 14 in/week). The effluent from Logan's
oxidation pond will be pumped approximately 1/2 of
a mile to the reclamation farm. Two test plots for
each application rate consisting of a forage crop,
alfalfa, and a soil only treatment plot will be irrigated
6 months out of the year for 2 years. One 4 in. drain
pipe will collect the return flow at a depth of 3 feet.
A sample port outside of the plot will allow the
collection and subsequent analysis of the return flow.
It is anticipated that only 14 inches/week will
saturate the soil to the point of producing a return
flow on a continuous basis.
A slotted two inch soil corning device will be
used to obtain samples on the various plots on a
weekly basis. The slotted corer will allow analysis of
the vertical stratification of the soil and its associated
water quality parameters. The upper most section of
the soU mantle will be most actively involved in
removal of the algal cells. The other water quality
parameters, BOD5, N-forms, P-forms,and dissolved
organic carbon will be analyzed on a vertical basis to
predict return flow characteristics.
Ten random samples will be obtained every two
weeks from the nine test plots. The following test will
be performed on the stratified samples over the two
6-month test periods.
Forage
Crop
Barren
Soil
Control
Organic Content
10/twice 10/twice 10/twice
monthly monthly monthly
N-Forms (NH4, 10
N03)
P-Forms (Total, 10
dissolved)
Soil moisture 10
BOD5 (If saturated) -
40
10
10
10
40
10
10
10
lo
The proposed method of application of oxida-
tion pond effluent is through a solid set irrigation
system. The system will be completely automated,
controlled by electric valves which will be varied to
give irrigation in blocks of four laterals operating
simultaneously. The system will be designed such that
the time of irrigation of any one block can be left
from a few minutes up to several hours, and the
-------
142 Gearheart and Middlebrooks
2in./wk.
7 in./wk.
(4 in./wk.
7 in /tub f
control
Holding
pond for
f.
Q
<
t
/f
Q
F(
T
\
J
X
P
fc
f
\
4
it
i
ft
y
3RAGE CROP
REATMENT
i
i
lagoon
TREATMENT ef"uent
100 ft.
1 ^
• f- A
i ~
I
i
r
«. ^
i c
i
i
i
i
From Logan/^
lagoon
i .
50 ft.
~* 1
1
C^50 ft. Drainage ports
I
•i A ^
1 W W
• ^ A
C, 3
• * A
• ft ^
1
1
) ]
.' J
.. cfc
(t
•i
Sprinklers spaced 3<
feet apart on 2" lia
elevated for a 6
1 * foot release.
4" perforated drain 36 in
deep
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 143
Table 1. Soil analysis for lagoon effluent irrigation study.
Texture
Organic Matter %
PH
ECe mmhos/cm
Phosphorus, ppm
Potassium, ppm
lime
Exchangeable Sodium, me/100 g
Total Sodium, me/ 100 g
Water Soluble Sodium, me/100 g
Cation Exchange Capacity, me/100
Percent Saturation
Drainage
Farm
Soil
clay
5.5
8.1
0.9
7.1
490
++
0.8
1.2
0.3
g 19.7
83
Hyde
Park
Bench
silt loam
1.9
7.6
0.6
4.5
398
-H-
0.2
0.2
<0.1
17.7
42
Brigham
City
Bench
sandy loam
2.3
7.1
1.1
13.0
171
+
0.2
0.2
<0.1
9.9
28
Four Miles
South Main
Logan
silt loam
3.7
7.4
0.5
27.0
490
+
0.3
0.3
< 0.1
23.6
56
system will automatically sequence from one block to
the next. Any one block can be completely skipped
in an irrigation sequence.
The sprinkler systems will be designed to
deliver 33 gpm/test plot. The sprinkler heads will
deliver .26 in/hour operating at 55 lbs/in2 with a
uniformity coefficient of above 85 percent. To
achieve the desired application rates of 2 in/week, 7
in/week, and 14 in/week at weekly irrigation periods
of 8, 24, 48 hours respectively would be required.
This would use a total of 115 hours a week which
would allow a simple timing control to operate off of
only one supply system.
Objective
To determine the efficiency of algal cell remov-
al from oxidation pond effluents spray irrigated on
one type of vegetation and on soil only control plot
and an effluent with no-algal cell control plot:
1. Design a drainage system for a one acre
experimental plot to monitor the effect of the
soU mantle system has on algal cell application.
2. Design a solid set irrigation system to deliver
three flow rates on three different experimental
plots as well as a control plot.
Install the drainage and irrigation system and
the sampling and flow measuring devices.
Spray irrigate the oxidation pond effluent on
the experimental plots measuring the following:
a. Initial algal cell concentration, BOD, sus-
pended solids, N-forms, and P-forms.
b. Continuous measurement of irrigation
rates, soil moisture, drainage return flow,
and evaporation rate.
c. Analyze drainage return flow for algal
cells, suspended solids, BOD, N-forms,
and P-forms.
d. Measure the productivity of the two
vegetation types at the three application
rates and with the no-algal cell effluent
irrigant.
e. Repeat the above experiment after the
first growing season in the fall and the
spring.
f. Determine the soil storage capacity as a
function of algal cell removal; determine
the application rate as a function of algal
cell removal; determine the vegetation as
a function of algal cell removal; deter-
mine the seasonal effect of algal cell
removal by the various experimental
plots.
g. Determine the system design based upon
cost of equipment, operating cost, and
any economic benefit from increased
production.
Introduction
Nature of the problem
During the last few years, people have become
increasingly concerned about the deteriorating
quality of the environment. This concern is beginning
-------
144 Gearheart and Middlebrooks
to express itself in many ways. Citizen action groups
have formed, laws are being passed, and more and
more research is being conducted in order to solve
these problems.
Among the laws being passed in the State of
Utah is a law that will increase the water quality
standards of most of the receiving waters in Utah
from Class D to Class C. As a result, the effluent
discharged into any of these receiving waters must
meet a more rigid standard of quality. The benefits of
such legislation should include more aesthetically
pleasing water and better environments for wildlife.
Obviously these improvements are extremely desir-
able and in general will be welcomed.
There are however, certain rather important
and critical considerations that arise from such a
course of action. In many cases wastewater treatment
facilities have already been constructed but were only
designed to meet Class D standards. When the Class C
standard becomes law, these existing facilities will no
longer be adequate and therefore will no longer be
allowed to discharge their effluents into any receiving
water covered by the law. The implication is clear.
Either existing facilities must be improved to the
point where the effluent can meet the new receiving
water standard, or a different method of disposing of
the effluent must be found. Improving present
facilities is going to be costly. At the hearings held in
Logan, Utah, in August of 1971, one industrial
representative asserted that the cost to his company
to meet the new standard would be in the neighbor-
hood of one million dollars. Sums of this magnitude
represent severe financial burdens for large com-
munities as well as industry. This figure becomes even
more alarming when initial capital costs are con-
sidered. But an even more critical situation is the
small community with a population of a few
thousand or less. The sums of money required will
probably be less, but still will be considerable. With
rather small tax bases, the large capital investment
required for treatment facilities that can meet the
standard is for all practical purposes out of the
question. When considered on a per capita basis, the
problem becomes even more clear. Given a tax
burden of one million dollars, a community of one
thousand taxpayers would each be required to pay
one thousand dollars. In a city of one hundred
thousand people, each taxpayer would only be
required to pay ten dollars. Therefore, the practice of
discharging treated waste effluent into the receiving
waters is no longer possible for these communities.
Obviously the problem becomes one of finding an
alternative method of disposal.
Purpose and scope of the study
The objective of this investigation is to study
the wastewater stabilization pond and the possible
use of the effluent as an irrigation water. Typical
pond effluents will be examined for possible toxic
effects of constituents and also for possible beneficial
effects such as fertilizer value.
Consideration will also be given to the applica-
tion of land use planning techniques for improving
stabilization pond system appearance and utilization.
Many pond systems perform rather well from an
engineering point of view, but appear as no more than
well engineered "holes-in-the-ground" visually. Sug-
gestions will be made for improving the appearance of
these ponds such that they improve rather than blight
the landscape. These suggestions will be supple-
mented with examples of actual projects to indicate
just a few of the possibilities available.
In summary the specific objectives to be dealt
with in this study are as follows:
1. Investigate the limitations of pond effluent
for use as irrigation water for crops.
2. Study the use of land planning techniques to
make ponds more visually pleasing.
3. From the above studies, make suggestions
for alternatives to meet the stated problems.
4. Suggest possible research activities neces-
sary.
Utah Water Quality Standards
Upgrading from Class D to
Class C standards
The difference between Class D and Class C
effluent quality standards can be compared by
referring to Table 2 (Middlebrooks, 1971). The most
significant difference between the two standards is
the 5-day BOD values. The reduction from 25 mg/1 to
5 mg/1 is the parameter that causes the greatest
concern. Middlebrooks et al. (1971) have shown that
present systems including waste stabilization ponds
do not meet Class C standards in this regard. It is this
aspect of the Class C water quality standards that
necessitates the rather expensive modifications
alluded to in the Introduction.
The other parameter of interest is the specifica-
tion of fecal coliform levels separately in the Class C
standard but not in the Class D standard. Middle-
brooks et al. (1971) have commented however, that if
a plant by proper operation is meeting the Class D
coliform standard, in all likelihood it will also meet
the Class C standard. Therefore the revised coliform
standard should not in general reflect itself in
increased capital cost improvements.
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 145
Table 2. Specific standards established for Class "C" and "D" water quality standards pertaining to wastewater
treatment plant effluents.
Concentration or Units
Parameter
Class "C"
Class "D"
PH
Coliform, monthly arithmetical mean
Fecal coliform, monthly arithmetical mean
BOD, , monthly arithmetical mean
Dissolved oxygen
Chemical and radiological
6.5-8.5
5,000/100 ml
2,000/1 00 ml
5mg/l
5.5 mg/1
PHS drinking water
standards
6.5 - 9.0
5 ,000/1 00 ml
.
25 mg/1
-
PHS drinking water
standards
An important implication of changing from
Class D standards to Class C standards is the improved
efficiency required of the existing plant. If it is
operating very inefficiently, the new facility will
either be overdesigned resulting in even larger capital
costs for improvements or it will be overloaded and
will not perform as required. The improved efficiency
is again likely to be an expense that would be
difficult for a small community to sustain.
The standards discussed above in effect apply
only to plants actually discharging effluents to
receiving waters. In other words, the change is not a
change of effluent standard but rather a change of
stream standard. Herein lies the possibility of using
stabilization pond effluents for irrigation. If the
standard was strictly an effluent standard, systems
would not be allowed to discharge their effluents at
all and thus total containment would be the only
alternative.
Waste Stabilization Pond Considerations
Economics
One of the most appealing aspects of stabiliza-
tion ponds is the relatively low capital cost required.
In Figure 4, a comparison of construction costs for
stabilization ponds relative to the construction costs
of several other types of conventional sewage treat-
ment facilities is shown (Economy in Sewerage
Design and Construction, 1962). The data were
compiled by the State of New York, but the figures
are generally consistent with other geographical areas.
Middlebrooks et al. (1971) performed similar investi-
gations for several areas which are consistent with
those compiled by New York. Clearly the waste
stabilization pond is much less expensive. Note in
Figure 4 that the cost of the land is not included.
Since pond systems usually require larger parcels of
land, the actual difference would be somewhat less.
Waste stabilization ponds offer another im-
portant economic advantage associated with the
operational aspects of the system. With trickling
filters or activated sludge one has a relatively
sophisticated process which requires constant super-
vision and highly skilled operators. On the other
hand, a waste stabilization pond from an operations
point of view is not as sophisticated and so the
supervision requirement and the level of skill needed
is subsequently lower. Both of these advantages will
manifest themselves as a savings in operation cost.
To put these cost figures into proper perspec-
tive, one must think about the situations for which
this investigation is intended. If a small town is
considering changing over from a septic tank system
to some type of central municipal system, clearly the
waste stabilization pond is the answer economically.
But as was pointed out in the section concerning
water quality standards, the Class C standard cannot
be met. Perhaps even more perplexing is the situation
where the community already has gone to the
expense of constructing a pond system and must
spend more money on a more sophisticated system in
order to meet the new standard. Obviously the need
to meet the standard stands in conflict with the
ability to raise the necessary funds.
Since the economics of the situation dictate
against more advanced treatment systems, some
alternative must be sought. The alternative which
seems rather appealing is irrigation.
Design
Since a great number of articles and papers have
been devoted to this subject, only a brief description
will be given here. Waste stabilization pond depth,
detention time, shape, mixing, and loading will be
discussed. These engineering aspects will be coor-
dinated with site planning considerations in the
design of a waste stabilization pond system.
-------
146 Gearheart and Middlebrooks
1000
o
- 500
o
O
100 -
50
• Trickling filter
Activated sludge
Primary sedimentation
Stabilization pond
I
I
.01 .05
E.N.R. Const, index = 1000
.10 .5
Design Flow (MGD)
1.0 5 10
Curves represent construction
costs only and do not include
land, engineering, legal or other
administrative costs.
Rgure 4. Sewage treatment plant construction costs.
The most significant effect of depth on the
ecology of the stabilization pond is the decrease in
light intensity with increased depth below the water
surface. Oswald et al. (1964) has shown that in order
for a pond to function aerobically throughout its
depth, the pond depth must be less than 1 foot.
Obviously, in general, this would be impractical
because the land requirement would become enor-
mous. Waste stabilization ponds, as most frequently
employed, range in depths between 3 and 7 feet
(Jones et al., 1971). Since light intensity penetrating
to these depths in most wastes is insufficient to
support photosynthetic activity, the lower regions of
these ponds are usually devoid of oxygen. These
ponds are referred to as facultative ponds. Another
aspect of pond depth that is important in the
operation and performance of the pond is the control
of emergent vegetation such as cattails and bulrushes.
This consideration suggests pond depths of at least 3
feet. Control of emergent vegetation is an important
step in controlling insects such as mosquitoes
(Kitterle and Enns, 1968). Another factor which
must be considered in determining the depth of the
pond is the water table. The cooling effects of
groundwater and the possibility of contaminating the
groundwater require that the pond bottoms be above
the local water table.
Pond detention times are important to allow
sufficient exposure of the waste to the biological
forces necessary to treat the waste. In conventionally
operated overflow type waste stabilization ponds, the
detention time generally ranges between 25 days and
3 months. Many ponds are operated on a non-
overflow basis so that inflow to the pond is balanced
by seepage and evaporation. To avoid contamination
of groundwater aquifers by ponds containing toxic
chemicals, it is best to minimize seepage. Detention
times are affected by temperature effects on
biological activity and so need to be longer in winter
than in summer.
Complete agreement as to the most effective
shape for waste stabilization ponds is not to be found
in the literature. One reason for this lack of definition
is that a pond is both a hydraulic system and a
biological system. A number of investigators have
argued that hydraulically, ponds are most efficient in
a two-to-one rectangular shape. Others have stated
that the optimum shape is round or square. Still
others feel that the shape is not nearly so restricted in
terms of overall performance. All agree, however, that
the cells should be regular in shape with no isolated
or partially isolated areas where circulation might be
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Separation of Algae Cells from Wastewater Lagoon Effluents 147
impeded, weed growth encouraged, etc. (Jones et al.,
1971).
Most authorities agree that multi-cell systems
are more successful than single cells. The principal
reasons for this are: (1) reduced tendency for short
circuiting, (2) less bank erosion caused by wave
action, and (3) more flexible operation (Jones et al.,
1971). They also produce waters of lower coliform
counts. Marais (1972) has done considerable work in
developing multi-cell theory. He found that single
pond systems were not as effective as multi-cell
systems in reducing bacterial counts. His calculations
show that for 90 percent removal, one pond is
sufficient; for 99 percent removal, two ponds are
needed; for 99.9 percent, three ponds; for 99.99
percent, four ponds, and so on.
There are two points of view concerning the use
and value of mixing. Pipes (1961) feels that a pond
operates most satisfactorily if it is kept completely
aerobic. Marais (1972) has shown that bacterial
die-away is greater in ponds where gentle mixing
occurs. He points out that an aerobic environment is
crucial in maintaining a high rate of die-away of the
fecal organisms. The rate of die-off diminishes sig-
nificantly when conditions become anaerobic. He
feels that with ponds in general, wind and tempera-
ture cause a gentle mixing and lead to the proper
conditions. In those cases where mixing does not
occur, Marais suggests some type of stirring
mechanism. The reason for the mixing is to induce
algal growth which in turn leads to greater oxygen
production. The other point of view, held by Oswald
et al. (1964) among others feel that both aerobic and
anaerobic conditions are necessary for best operation.
When mixing occurs, oxygen is sent into the
anaerobic region. Methane bacteria which perform an
important part of the anaerobic process are very
sensitive to oxygen and are thus unable to function.
Another aspect of mixing is the contribution
from wind. Initially wind was considered useful
because it increased the effective surface area and so
allowed greater aeration. More recent thinking (Jones
et al., 1971) tends to look upon wind with disfavor
because of several reasons: (1) The question of the
value of mixing, (2) the insignificant amount of
aeration that actually occurs, and (3) the loss of
water quality because of increased evaporation rates
with associated increased chemical concentrations.
Wind can also cause increased soil bank erosion by
wave action and disperse odors into populated areas.
In view of these disadvantages, sites now are recom-
mended that have some sort of screening to reduce
wind effects.
Pond loading is one of the key technical aspects
of the design. The total pond area required to treat
the waste of a given community is determined on the
basis of organic loading in most cases, usually
reported in terms of pounds of BOD per acre per day.
Oswald et al. (1964) give the maximum load on
facultative ponds as 60 pounds BOD per acre per day.
However, the values most frequently recommended
fall in the range of 20 to 50 pounds BOD per acre per
day. It is obvious that when a pond has been
overloaded, its operating efficiency is reduced. It may
not be obvious however, that underloading can also
hinder performance. Herman and Gloyna (1958)
among others have pointed to low organic loadings as
the cause of unsatisfactory pond performance. Some
recent research (Assenzo and Reid, 1966; Meenaghan
and Alley, 1963) has thrown suspicion on the surface
area loading criteria. It indicates that a volume
loading criteria would be more rational, particularly
in the case of facultative and anaerobic ponds.
Land Use Planning Considerations
Introduction
Too often in the past designs for waste
stabilization pond systems have neglected an im-
portant aspect of the design, site planning. The
consequences of such an approach are installations
that, despite their technical performance, are unsight-
ly. Not only is the appearance undesirable, but
important natural design elements that could marked-
ly improve the overall design are not taken into
consideration. Clearly the best design can only be
achieved by becoming familiar with all design tools
available whether they come from the area of
engineering or the related fields of site planning and
landscape architecture.
This chapter will present an inventory of a few
of the more important tools available from the field
of landscape architecture. Because the process of site
planning has no best approach, no attempt will be
made to describe a step by step process. Such things
as plant materials and wildlife wUl be shown to offer
great potential in solving certain problems inherent to
waste stabilization pond installations. Only a few of
the potential planning concepts will be mentioned.
No attempt will be made to list all of these things or
to explore their usage in great depth. Some of the
considerations in site selection will be given when
planning a pond installation. Two examples of
projects that were designed with the inclusion of
planning concepts will conclude the section.
Site selection considerations
Site planning is based on two primary con-
siderations. First, the nature of the site, its character
and its distinguishing and unique features must be
considered. Second, consideration must be given to
-------
148 Gearheart and Middlebrooks
the human purpose for which the site is to be used.
These two considerations are linked together in a
circular way that is rather interesting (Lynch, 1962).
The purpose for which the site is to be used will
influence the interpretation of the inherent
characteristics of the site. At the same time, the
inherent characteristics of the site determine the
purpose for which the site may be used. As one can
see, these two considerations must be merged togeth-
er in some manner in order to optimize the use of
the site. Failure to successfully merge these two
considerations will result in a system aesthetically
displeasing and possibly substandard in engineering
performance.
The primary purpose of the waste stabilization
pond for this study, besides the obvious treatment
aspect, is to provide a source of irrigation water. This
allows effective disposal of the effluent and at the
same time offers an agricultural benefit by possibly
reducing costs. In terms of planning, a number of
implications arise. If agriculturists are going to use the
water, the pond system site may need to be centrally
located in order to provide the most effective service
to the users. Future land use projections are im-
portant in this regard so that today's genius does not
become tomorrow's folley.
A centrally located site may not be the best
site. Certain locations may require costly distribution
systems and added pumping costs. It may be that by
using an alternative site not centrally located, some
natural terrain feature such as a hill or a deep ravine
may be avoided with a resultant savings in cost. This
saving should be compatible with the need for
efficient service to the individual user.
Another important consideration is the pump-
ing requirement dictated by the site. If the pond
system is built in the low point of a valley, gravity
flow can be used to transport the waste to the
stabilization pond. However, with the ponds at the
lowest point, effluent distribution will then require
extensive pumping unless the users are close to the
pump (assuming there is no abrupt change in topo-
graphy). One would generally tend to regard such a
situation as unlikely because low points in valleys are
often swampy and are not usually suitable for
agriculture. Where exceptions do occur, the alter-
natives for decision making are expanded.
Problems amenable to
planning techniques
The problem of odors could become rather
significant if the pond system was near a residential
area. If a pond system was situated in a low valley
area, the problem would be still greater. The odors
would be harder to diffuse because of the cool damp
air which would tend to hang in a depression of this
type. In general, the literature asserts that when
ponds are properly designed, odor problems do not
occur. If odors do become a problem, certain
chemical treatments such as chlorination, aeration,
and additional nutrients are commonly used. Planning
techniques can also be useful in overcoming any odor
problems which might occur.
The concept of pond mixing by wind action
can also present problems. Bank erosion due to
excessive wave action is an important consideration in
this regard. On the other hand, Marais (1972) felt
that mixing was useful and that sun and wind were
important contributors to this mixing.
Mosquitoes and other insects are significant
problems. This is particularly so if some type of
recreational area or activity is planned as part of the
pond system design. Control of emergent vegetation
in the ponds has been cited as the major deterrent to
these pests. Even so, chemical treatments (DDT for
example) are still apparently necessary. Planning
techniques can offer some rather interesting ap-
proaches to this problem.
Another problem is the type of site commonly
selected. Frequently sites are chosen where the soil
condition is poor and not amenable to most plants.
This adds to the unsightly appearance of the pond
system since plants and trees commonly used for
beautification will not survive in such unfavorable
conditions. Again by utilizing the talents of the
landscape architect, this situation can be successfully
approached.
The water table depth must be ascertained. If
the water table is high, precautions must be taken to
protect the groundwater from contamination and to
prevent seepage into the pond system and affect the
designed loading rate. The depth of the water table
may also influence the type of vegetation that one
may want to introduce.
The topography also is an important considera-
tion not only for the obvious reason of reducing
construction costs on smoother land but for potential
advantages of modifying the microclimate. Steep
slopes are of course undesirable but flat ground may
not be the best answer either. A careful study of the
individual situation must answer that question.
The stated considerations do not constitute all
the elements that require the designer's attention, but
do indicate the importance of this step. It should also
be clear that the engineer can reach a better conclu-
sion by collaborating with a landscape architect who
is trained in the field of site analysis.
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Separation of Algae Cells from Wastewater Lagoon Effluents 149
Planning techniques
An existing berm may lend itself to the overall
design. It may be used for modification of the wind
effects by acting as a screen or wind break. By using
it as a buffer, the wind can be modified so that wave
action in a stabilization pond is reduced with an
associated reduction in bank erosion. A berm could
be used as a deflector to encourage mixing and so
encourage the aerobic conditions recommended by
Marais (1972). The berm could be used as a visual
screen to cover objectionable aspects of the installa-
tion. Berms might also assist in the distribution of
sewage flow from pond to pond by providing
different levels for series ponds to be built and
therefore allow gravity flow. The design of natural
and man-made berms in this distribution can be best
handled with a collaboration of engineer and land-
scape architect to optimize performance and ap-
pearance.
The berm may lend itself nicely if some
recreational activity is desired. A park's beauty can be
enhanced by recongizing the potential and then
allowing the landscape architect to use his talents to
maximize its effect. Nearby hills may also function as
game preserves and thus attract wildlife. This in turn
can add to the beauty of the surroundings which will
make the area more attractive if a park is intended.
Obviously a berm may represent a vital parameter and
before simply bulldozing it flat, a competent land-
scape architect should evaluate its potential.
The use of existing and induced plant materials
can provide a great number of advantages. By using
existing plant materials in combination with judicious
induced planting, the general public can be dis-
couraged from entering certain areas reserved for
maintenance personnel and encouraged to use the
areas set aside for the public. Trees can be used to
screen off areas from view which are unsightly.
Conversely if certain views are desirable, trees can be
used to frame these sights and thus bring emphasis to
the sight for the viewer. Trees are effective as wind
breaks and are even more effective for wind modifica-
tion than are berms. In a study conducted at the
Kansas Agricultural Experiment Station (Olgyay,
1963), trees were shown to reduce wind effects over a
much greater distance beyond the wind break than
solid wind breaks. The solid type was able to provide
greater close-in reductions but velocities returned to
original values sooner.
Correct usage of trees can modify and reduce
odor problems. Certain trees such as the black locust
and the tree of heaven emit aromas that can markedly
reduce offensive odors. The mechanism is dilution
and is effective. Flowers can also be useful in this
same regard.
Trees can also be used for space definition.
People are rather clearly affected emotionally by the
type of space they find themselves in (Simonds,
1961). If the space is high and majestic, people might
be affected with the sense of feeling small and
overpowered. If the space has a low overhead and is
not large, the feeling could be intimate and conducive
to fellowship and small social gatherings such as
family picnics. If a park is to be a part of the design
these factors become important in terms of human
scale and desired response. Frequently one sees an
area that appears pleasing to the eye but no one uses
the area. One possible explanation is that the space
relationship of the area makes people feel uncomfort-
able. Only through the skillful use of these concepts
will such an area really be successful.
The use of trees and other plant materials for
attracting specific birds that consume insects can
provide a distinct benefit. Using birds in this way
reduces insecticide requirements, saves money, and
reduces the hazard of pesticide accumulations in the
ecology. As was mentioned above, mosquitoes are
largely controlled by preventing emergent growth.
The mosquito population and other insect and fly
problems can be further controlled by birds. Purple
martins for example eat several times their body
weight each day in insects. And since purple martins
prefer lots of company, attracting this specie would
provide a large number of birds which could almost
virtually destroy any insect problems inherent to
stabilization ponds. Wrens and bats among many
others are also effective against insects. To utilize this
very effective tool requires a knowledge of the kinds
of plant materials or man-made structures (birdhouses
for example) that will attract and keep these forms of
wildlife (Davison, 1967; Stefferud, 1966). Again a
competent landscape architect can offer assistance.
Examples of planning applications
After reviewing the discussion under Design,
one should note that the use of shape for aesthetic
design seems rather plausible. There are of course
some limitations but perhaps something more organic
than an ordinary rectangle is possible, as described by
Oswald et al. (1967). The project was the construc-
tion of a waste stabilization pond system for a
subdivision. The design was the integration of
engineering and landscape architecture and resulted in
a product vastly superior to a mere well engineered
"hole-in-the-ground." The design is shown in Figure
5. Of significance are the pond cells which are not as
stiff and formal as the common rectangle. The system
also has been integrated into a park allowing for
multiple use of the land. The designers have used
many trees which meet the new thinking concerning
reduced mixing for pond systems. The multi-cell
design also offers improved treatment potential. The
-------
150 Gearheart and Middlebrooks
most important overriding conclusion with this
example is the obvious compatibility between the
two disciplines, engineering and landscape
architecture. The increased cost for aesthetics results
in a significant benefit for the citizens of that
community. At the date of publication the project
had not been constructed, but the ideas had been
used in other projects. The authors call attention to
one project, the Esparto ponds in California. They
were interested in determining the possible odor
problems since the system would be close to habita-
tions and subsequently found that an odor nuisance
did not result. They also found that visual and public
health restrictions were also met.
Another project illustrating the use of good
planning is the Santee project (Merrell et al., 1967).
The Santee project is a total reclamation project
Figure 5. Pond system in park of subdivision design.
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Separation of Algae Cells from Wastewater Lagoon Effluents 151
which includes several small reservoirs which serve as
tertiary treatment. The project shows that a design
can successfully include more than pure engineering.
The Santee project includes areas for picnicing,
boating, fishing, and even swimming. Here is multiple
use of land with great variety resulting in benefits to a
broad spectrum of people.
Whether one likes or dislikes the actual designs
of the aforementioned projects is not as important as
recognizing the feasibility of considering aesthetics in
the overall design. The Santee project clearly shows
the benefits of such planning by the number of
people using the facilities. A good many users are
tourists which of course brings an economic benefit
to the community. This to some degree answers the
question of greater project cost.
Based on the above considerations, the
approach used by Oswald et al. (1967) in combining
the talents of the engineer and the landscape architect
seems desirable. This combination provides the sound
technical basis for site planning and construction
available from both disciplines plus the element of
sharpened sensitivity to aesthetic values which is the
most important tool of a competent landscape
architect. Though such a combination clearly will
increase the design cost, the long range benefits
possible should be carefully considered before dis-
pensing with planning considerations.
Effluent Components Considered
for Irrigation
Introduction
Thus far in this discussion, the waste stabiliza-
tion pond has been looked at in terms of economics
and been found to offer distinct advantages over
other types of conventional systems. Their operation
and design has been studied and found to offer good
wastewater treatment capability. Land use planning
techniques were then discussed showing some of the
considerations that can integrate the pond system
into a community most effectively. In particular the
land use concept of the pond system as a source of
irrigation water was discussed. All of these considera-
tions have shown the feasibility of the pond system as
an irrigation source. The one remaining question is
the chemical and bacteriological quality of the water.
Pertinent to the water quality discussion is the
municipal use and its effect upon that quality. The
chemical quality of the wastewater effluent is
basically the sum of the original chemical quality and
the municipal increment added. Conventional
secondary treatment facilities only slightly affect the
chemical quality. Their principal effect is in the
biological area. The average municipal increments for
a number of constituents are shown in Table 3 (U.S.
Public Health Service, 1963). Specific industrial
Table 3. Average increments added by community use of water.3
Overall
Eastern
Western
Pollutants
BOD
COD
ABS
Na+
K+ .
NH4
Ca++
Mg++
ci-
NO;
NOf
NCOs
C0j=
so4-
Si03=
P04-3 (total)
PO;3 (ortho)
Hardness (CaC03)
Alkalinity (CaCO3)
IDS
Average
22
111
6
69
10
19
17
7
75
9
1
104
-1
28
16
24
22
69
85
323
Range
8- 45
36-218
2- 10
8-115
7- 15
3- 50
1- 44
0- 24
14-200
0- 26
0.1- 2
-44-265
0--10
10- 57
13- 22
2- 50
7- 34
10-185
-35-217
128-541
Average
21
96
5
59
9
21
24
8
53
11
0.8
147
-1
28
15
19
20
95
121
287
Range
8- 33
36-159
2- 10
42- 98
7- 12
9- 29
1- 44
3- 11
14-102
0- 26
0.1- 2
49-265
0- -5
12- 52
15
2- 35
12- 34
15-151
40-217
128-457
Average
23
218
8
74
11
18
13
7
92
7
2
81
•1
29
17
28
25
58
66
352
Range
10- 45
218
6- 9
8-115
7- 15
3- 50
2- 30
0- 24
20-200
0- 15
2
-44-247
0--10
10- 57
13- 22
7- 50
7- 34
10-185
-36-203
194-541
"Source: U.S. Public Health Service (1963).
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152
Gearheart and Middlebrooks
discharges into the community system could totally
distort the value for a given component. Since
generally communities will have a good source water,
problems that may arise in using the effluents for
irrigation are usually the result of the increments
shown in Table 3.
The Utah State Division of Health has con-
ducted extensive chemical quality tests on a great
many waters of the state including several stabiliza-
tion pond effluents. Data from these tests are
summarized and presented in Tables 20 to 24 by the
Utah State Division of Health (1968, 1969, 1970) in
the Appendix. Based on the water quality factors
tested by the Division of Health, an extensive
literature review was performed to determine the
effects of these constituents on the water quality for
irrigation use. Beneficial as well as toxic effects are
described.
In reviewing the literature it was discovered
that a great many studies have been performed on the
interactions of one component in the presence of a
second. No attempt was made to include this infor-
mation, except in a few cases, because of the great
number of these papers.
Arsenic
Arsenic can be beneficial or toxic to plants
depending on the concentration of arsenic and the
specie of plant. Even though some beneficial results
have been noted, arsenic is not presently considered
an essential nutrient for plant survival and health. In
toxic concentrations arsenic can cause rotting of
roots, arrest seedling germination, and reduce seedling
viability. Arsenic primarily settles in the root system
resulting hi significant plant growth reduction before
it goes to top-growth. This means that a plant can be
damaged without visible symptoms occurring. When
physical damage is apparent, the damage seems to be
the destruction of chlorophyll in the foliage. This
condition is referred to as chlorosis and generally
appears as yellowing of the plant leaves.
Several investigators have performed extensive
investigations regarding the extent of arsenic in soils.
Williams and Whetstone (1940) found in testing a
wide variety of soils that natural arsenic occurred in
concentrations from 0.38 ppm to 38.0 ppm. Moxon
et al. (1944) found in studies of cretacious forma-
tions concentrations of 0.2 ppm to 64.4 ppm.
In studies conducted to determine toxicity
levels, Vandecaveye et al. (1936) found that the soil
samples from the top 6 inches of a number of
unproductive fields contained from 4.5 to 12.5 ppm
of readily soluble arsenic calculated as As203.
Marked retardation of growth of young alfalfa and
barley plants was noted. In other experiments,
Lieberg et al. (1959) applied several concentrations of
arsenic and found that at a concentration of 1 mg/1,
either as arsenate or as arsenite, the growth of lemon
trees was stimulated. However, when concentrations
of 5 mg/1 of arsenate or 10 mg/1 of arsenite were
applied, these concentrations were found to be toxic
to top growth and root growth.
Bicarbonate and carbonate
Other than pH control, no evidence could be
found that either carbonate or bicarbonate offers any
beneficial effect at all. Evidence does exist however,
that excessive amounts of these ions can be directly
or indirectly toxic to plant growth.
Porter and Thorne (1955) found that sodium
bicarbonate in substantial concentrations was in-
directly responsible for iron chlorosis in beans and
tomatoes. They used 10 meq/1 sodium bicarbonate
and observed a decrease in both chlorophyll content
and growth compared to a concentration of only 0.3
meq/1. Amon and Johnson (1942) found that by
using lettuce, tomatoes, and bermuda grass, plants
grew satisfactorily at pH values of 4 to 8 assuming
plant nutrients were available. At pH values of 3 or
less and 9 or greater, plant growth was reduced.
Harley and Lindner (1945) found that high
concentrations of bicarbonate ion in irrigation water
over a period of years produced a detrimental effect
upon peat trees and apple trees. When the concentra-
tion was 3.44 meq/1 to 5.0 meq/1, a marked decline in
vigor was noted. A water with 1.5 meq/1 showed no
ill effects. Chlorosis was the predominant disorder in
pears, but was only sporadic in apples. In addition
lime concretions formed around roots and small
carbon nodules formed on fibrous roots. These
effects were entirely absent from trees irrigated with
low bicarbonate concentrations.
In addition to chlorosis other undersirable
effects from bicarbonates have been shown to occur.
Steward and Preston (1941) found that large con-
centrations of potassium bicarbonate and dissolved
carbon dioxide reduced protein-, synthesis and
bromide accumulation by potato discs. At 20 meq/1
of potassium bicarbonate, protein synthesis was
almost totally arrested. Hassan and Overstreet (1952)
found that increasing from 0 to 200 meqA of
bicarbonate ions reduced radish elongation. At 50
meq/1, elongation was reduced by 65 percent and at
200 meq/1, elongation was reduced by 98 percent.
Bicarbonates may also affect plants indirectly.
One rather common effect is the reaction with
available calcium ions to form calcium carbonate. The
removal of available calcium acts to increase the
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Separation of Algae Cells from Wastewater Lagoon Effluents 153
sodium hazard by increasing the SAR value (refer to
the section concerning sodium). Misra and Mishra
(1969) found that carbonates, when added to a soil,
reduce the availability of manganese in black, red, or
alkali soils. Since manganese is an essential plant
nutrient, this effect takes on some importance. The
carbonates were shown to reduce the availability of
manganese regardless of whether the carbonate was
soluble or insoluble. (Refer to the section on the
characteristics of manganese for more information.)
Wadleigh and Brown (1952) found that beans
and Dallis grass are very sensitive to bicarbonate
concentrations and that Rhodes grass and beets are
relatively tolerant.
Studies have been made in order to specify
tolerance limits for bicarbonates and carbonates in
irrigation water. One such specification was based on
the amount of residual sodium carbonate present.
Residual sodium carbonate is defined as follows:
RSC = (C0= + HC0" ) - (Ca
Mg"1"1")
where the ion concentrations are in meq/1. Wilcox et
al. (1954), in establishing limits for residual sodium
carbonate, used Rhodes grass in sandy loam soil
under greenhouse conditions. Waters containing more
than 2.5 meq/1 of residual sodium carbonate are
unsuitable for irrigation over a long period without
use of amendments, 1.25 to 2.5 meq/1 is marginal,
and less than 1 .25 meq/1 is probably safe.
Boron
Boron has for some time been acknowledged as
one of the essential nutrients for plant growth. After
the laying of much groundwork by early investiga-
tors, this fact was firmly accepted after the work of
Sommer and Lipman (1926). Deficiencies of boron
can cause any of several non-parasitic diseases. Some
of these include top sickness of tobacco, heart-rot of
sugar beets, cork disease of apple, brown rot of
cauliflower, and raan of rutabaga.
Boron deficiencies will generally not occur if
the water being used has a concentration of 0.10 to
0.20 ppm and is used in quantities of 1 acre-foot or
more. A deficiency may occur under certain condi-
tions in the presence of the calcium ion. Chapman
and Vanselow (1955) showed that water low in boron
but high in calcium will cause plants to exhibit an
increased need for boron.
Boron may also be highly toxic to plants in
excessive concentrations. Some plants, particularly
citrus trees, are very sensitive and can be damaged by
concentrations as low as 0.75 ppm. Table 4 is a table
of plants and their tolerance to boron prepared by
Eaton (1939). Notice that he classifies sensitive crops
Table 4. Relative tolerance of plants to boron.
Tolerant
4mg/l
Athel
Asparagus
Palm
Date palm
Sugar beet
Mangel
Garden beet
Alfalfa
Gladiolus
Broadbean
Onion
Turnip
Cabbage
Lettuce
Carrot
2mg/l
Semitolerant
2mg/l
Sunflower
Potato
Acala cotton
Pima cotton
Tomato
Sweetpea
Radish
Field pea
Ragged robbin rose
Olive
Barley
Wheat
Corn
Milo
Oat
Zinnia
Pumpkin
Bell pepper
Sweet potato
Lima bean
1 mg/1
Sensitive
1 mg/1
Pecan
Black walnut
Persian walnut
Jerusalem artichoke
Navy bean
American elm
Plum
Pear
Apple
Grape
Kadota fig
Persimmon
Cherry
Peach
Apricot
Thornless blackberry
Orange
Avocado
Grapefruit
Lemon
0.5 mg/1
Source: Eaton (1939).
as those that will show slight to moderate injury at
levels of 0.5 to 1.0 mg/1, semitolerant at levels of 1.0
to 2.0 mg/1, and tolerant crops at levels of 2.0 to 4.0
mg/1. In general past writers have left the impression
that concentrations in excess of 4 or 5 ppm boron
would cause serious damage to even the very tolerant
plants. Investigators in the last 10 years however,
have found that certain plants are much more
tolerant than previously thought.
Oertli et al. (1961) performed a number of
experiments with several varieties of turfgrass and
found them to be very tolerant of boron. They
subjected the plants to concentrations up to 10 ppm
without any apparent reduction in growth. At 10
ppm, damage did occur at the leaf tips. This did not
prove to be significant because the damage could be
easily removed by frequent mowing.
In another study, Oertli and Roth (1969)
studied the effects of boron on sugar beets, cotton,
and soybeans. Their results showed sugar beets to be
unusually tolerant. Even at concentrations of up to
25 ppm of boron, yields were not diminished.
Applications of 40 ppm resulted in some leaf damage
but yields were still rather good. Cotton showed a
considerable tolerance for boron although less than
sugar beets. Yields did not begin to drop off
significantly until concentrations of 15 ppm were
applied. Soybeans proved to be the most sensitive.
-------
154 Gearheart and Middlebrooks
Yields were significantly affected at concentrations
greater than 5.0 ppm. Notice however, that soybeans
would be considered a tolerant crop using Eaton's
(1939) criteria, Table 4.
Boron toxicity can also vary considerably de-
pending on the stage of the plant. Langille and
MaHoney (1959) conducted studies on oats and
found that boron injury was quite dependent on the
stage of growth. Boron was applied at the rate of 35
pounds per acre of borax (h^B^jO^lOr^O) to a
field of oats underseeded to a Ladino clover mixture.
With the first noticeable oat growth, there appeared a
definite chloratic condition of the oat seedlings on
plots treated with boron. Affected seedlings showed a
distinctly yellow and in some cases almost white
appearance. The untreated areas appeared lush and
green. However, as the plants began to mature, the
injury began to decline rapidly. At the end of the
season the average yields from the treated and
untreated plots were 61.6 and 61.4 bushels per acre
respectively. These yields indicate that the boron
toxicity noted earlier in the season did not cause a
reduction in yield under the conditions of the
experiment. After examination of the plants and the
soU, the authors suggest a minimum toxic level of
0.84 ppm of boron in the water. Concentrations of
0.84 ppm or less appeared to cause no apparent
damage. This seems to disagree slightly from Eaton
(1939) but the difference does not appear significant.
In a study using peach trees, McLarty and
Woodbridge (1950) studied the effects of boron both
in toxic and deficient amounts. When boron levels
were deficient the peach trees showed significant
die-back in the spring of twigs and branches on trees
which had grown normally the previous season when
boron levels were adequate. There was no warning
this would occur. Leaf and flower buds appeared to
form normally but failed to "break" normally when
growth started in the spring.
When boron was in excess, small necrotic areas
developed in the leaves along the midrib eventually
resulting in perforations in the leaf. Small cankers
sometimes also developed on the underside of the
midrib and in the petiole. In more severe cases,
cankers developed along the stems, tips of branches
withered, and gumming occurred. Leaf symptoms like
those described above were induced on 2-year old
peach trees with the application of 5 ppm boron. The
trees in general seemed to recover the following year
when the excess boron application was discontinued.
Kelley et al. (1952) found that with carrots
grown in sand cultures, boron toxicity symptoms
occurred at 5 ppm for carrots grown in the summer
and 10 ppm for carrots grown in the winter.
Apparently boron toxicity in certain plants is quite
sensitive to climate. Carotene content was in-
dependent of boron supply for all levels greater than
needed to overcome deficiency.
Cadmium
Not a great deal has been presented on the
potential toxicity problems related to plants. McKee
and Wolfe (1963) suggest a tollerance limit of 0.005
mg/1 for irrigation water on a long term basis. They
based this value on two assumptions: (1) reported
toxicity levels are correct (Lieber and Welsch, 1954)
and (2) cadmium behaves like zinc relative to plant
uptake and soil reactions.
In a study Schroeder and Balassa (1963) found
that when vegetables normally devoid of cadmium
were grown in soil heavily fertilized with 20 percent
superphosphate (H2P04~), the plants absorbed cad-
mium. These plants included potatoes, string beans,
beets, onions, peas, and carrots. They also found that
vegetables normally containing cadmium absorbed
larger quantities than normal. The plants were let-
tuce, turnips, radishes, and parsnips. The super-
phosphates were found to contain 7.25 ppm cad-
mium. The authors concluded that superphosphate
can increase the cadmium uptake of plants and
thereby reduce the plant's tolerance to cadmium.
In the same study, the authors applied a large
amount of superphosphate to one of three plots of
vegetables. Growth of the fertilized plot was far more
lush than that of the two unfertilized plots. The
plants used were peas, swiss chard, beets, and turnips.
Schroeder and Balassa (1963) concluded that the
plants were not damaged by 7.25 ppm cadmium.
Calcium
Calcium is another of the 16 basic elements
required for plant growth. It is the dominant base of
a "normal" soil. In addition to the benefits to plant
growth and soil structure, calcium also offers benefits
for biological activity. If soil conditions become
either too acid or too alkaline, calcium will become
deficient.
As pointed out in the section on boron, calcium
can reduce the toxic effect of boron. Cooper et al.
(1958) found that concentrations of calcium nitrate
added to a water of 6.9 ppm of boron in amounts
that increased the electrical conductivity of the
saturation extract from 5.5 to 7.2 millimhos/cm
reduced the usual boron effects by one-third. Calcium
is then a useful amendment for reducing problems of
boron toxicity.
The presence of calcium in the soil can cause
potassium to be more readily available to plants.
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Separation of Algae Cells from Wastewater Lagoon Effluents 155
York et al. (1954) showed that when lime and
potassium fertilizer were used together growth yields
were increased.
Excessive concentrations of calcium can also
cause detrimental effects. These effects generally
stem from calcium reacting with certain ions in the
soil. For example, if calcium combines with
carbonate, a.buffering effect results. This in turn
produces a decrease in nutrient availability. In addi-
tion, with calcium being precipitated as calcium
carbonate, the sodium hazard increases (see section
on sodium). Lund (1970) studied calcium and its
effects in relation to magnesium using soybeans for
his crop. He used a ratio of the calcium concentration
divided by the sum of the calcium and magnesium
concentrations to make evaluations. He determined
that when the ratio of calcium to magnesium was
small, depressed root growth occurred even when
calcium was present in concentrations of 40 ppm.
Taproot harvest length after 7& days of growth was
299 mm with a calcium to magnesium ratio of 0.05.
With a ratio of 0.20, the length was 485 mm.
Chloride
Chlorides are another of the essential nutrients
for plant growth. Though generally not phytotoxic,
in excessive amounts chlorides can cause leaf tip
burn, premature yellowing, and at times chlorosis in
some plants.
A number of investigators have worked in the
area of chloride deficiency with interesting results.
Raleigh (1948) studied the effect of chloride addition
to a chloride deficient culture solution on table beets.
He found that when several millequivalents of
chloride were introduced, the yield increased sig-
nificantly. Harward et al. (1956) working with Irish
potatoes had similar results in increasing yields.
Corbett and Gausman (1960) also studied potatoes
with significant yield increases when chloride
deficiencies were treated with added concentrations
of chloride.
Table 5 (Eaton, 1966) shows some common
plants and their suggested tolerance to excessive
chloride concentrations. Note that fruit trees are
relatively sensitive whereas certain vegetables and
grains are rather tolerant. However, these limits can
be readily modified by leaching. It is also important
to realize that though these limits are helpful, usually
salinity levels are more important than chloride levels
because salinity will ordinarily reduce crop growth
first.
A number of studies have investigated the toxic
effects of excessive concentrations of chloride. Con-
centrations as low as 3 meq/1 of chloride in irrigation
water have caused injury to citrus, stone fruits, and
almonds (Bernstein, 1967). Bingham et al. (1968)
found that the application of 5 meq/1 of chloride in
irrigation water could constitute a hazard to avacado
trees.
Foliar absorption of chloride has been found to
be of importance when using sprinkler irrigation
(Eaton and Harding, 1959; Ehlig and Bernstein,
1959). The difference in evaporation between day
and night and the amount of evaporation occurring
between revolutions of the sprinkler head can cause
adverse effects.
Meron et al. (1965) in a study performed in
Israel found that high chloride concentrations may
cause slow but eventually fatal physiological injury to
citrus trees. The authors also state that as of 1965,
chloride concentrations in the range of 150 to 200
mg/1 (4.15 to 5.55 meq/1, respectively) are accepted
for irrigation of citrus trees, and chloride concentra-
tions of 300 mg/1 (8.3 meq/1) are accepted for other
agricultural crops.
Table 5. Tolerances to chloride, as measured in sand and water cultures.3
Low Tolerance
GassI
Peach
Avocado
Lemon
Prune
Bean (navy)
Plum
Dallis grass
13
14
15
16
18
18
19
Medium Tolerance
Class II
Strawberry
Apricot
Orange (Valencia)
Rice
Sorghum
Alfalfa
Rhodes grass
Bean (kidney)
20
20
20
23
23
23
24
24
High Tolerance
Class III
Wheat (young)
Tomato
Cotton
Flax
Corn (young)
Barley
Beet
25
39
50
50
70
90
100
aChloride concentrations in meq/1 producing 80% growth 01 yield.
Source: Eaton (1966).
-------
156 Gearheart and Middlebrooks
Copper
Evidence was presented by Sommer (1931) and
by Lipman and MacKinney (1931) that copper was
an essential nutrient for plant growth. Sommer
(1931) found that when copper was eliminated from
the diet of tomatoes, sunflowers, and flax that
growth reductions up to 90 percent occurred. Lipman
and MacKinney (1931) found that barley gave normal
growth when fed one part cooper in ten million parts
of nutrient culture solutions made from highly
refined chemicals. When copper was omitted, the
plant did not fruit properly. Because of a large
amount of circumstantial evidence built up before
these two papers, the evidence of 1931 was accepted.
In a study done on a copper deficient soil in
Manitoba, Canada, Campbell and Gusta (1966)
realized significant yield increases of carrots and
onions with the application of only 0.5 pounds/acre
of copper. An increase to 2.5 pounds/acre of copper
gave no further increase but caused no adverse effects
either. The quality of the onions was also improved.
Copper can act toxically if in excess quantities.
Anne and Dupuis (1953) among others have shown
that toxic amounts of copper can reduce growth and
may depress iron concentrations in leaves causing iron
chlorosis symptoms. Forbes (1917) showed that
excessive copper could also cause root damage. Amon
(1950) found that a 2.0 mg/1 concentration of copper
in a nutrient solution was toxic to tomato plants.
Smith and Specht (1953) found that a 0.1 mg/1
concentration was toxic to orange and mandarin
seedlings. Millikan (1949) found that a concentration
of 0.5 mg/1 in a water culture caused damage to flax.
Hewitt (1953), using a sand culture, found that
nutrient solutions containing 6.4 to 31.8 mg/1 of
copper caused damage to sugar beets, tomatoes, and
potatoes but not to oats and kale. Tolerance levels
have been suggested for copper in irrigation water
which agree in general with the above findings. Values
of 0.1 mg/1 (McKee and Wolfe, 1963) and 0.2 mg/1
(National Technical Advisory Committee on Water
Criteria, 1968) have been suggested. Small dis-
crepancies may be accounted for because irrigation
water has an alkalyzing effect (increase of the
exchangeable-sodium content of a soil) which may
reduce copper availability and bring on deficiency.
This is especially common in sands and high organic
soils.
Hunter and Vergnano (1952) found that when
oats received 2.0 ppm copper in a nutrient solution,
they were usually normal, though some showed slight
interveinal chlorosis. Those that received 10.0 ppm
were very chlorotic. With concentrations of 20.0 ppm
or greater, the plants were small and the leaves
narrow. A few were chlorotic but most were orange
colored. Above 2.0 ppm, roots showed a decrease in
size.
Fluorine
Fluorine is not considered an essential element
for plant growth. It can however, cause toxic effects
in excess amounts. Injury appears as marginal necrosis
(leaf tip burn) and/or interveinal chlorosis.
The amount of fluoride uptake by the plant has
been shown conclusively to be independent of soil
concentration by Hurd-Karrer (1950) among others.
The determining factors seem to be soil type, calcium
and phosphorus content, and pH. Hurd-Karrer (1950)
also demonstrated that excess quantities of soluble
fluorides applied to unlimed acid soils will cause plant
injury. On the other hand, addition of soluble
fluorides to well limed soils or the addition of
insoluble fluorides to acid or limed soils caused no
apparent injury. Soils at a pH of 6.5 will almost
completely fix any soluble fluoride compounds in the
soil or added to the soil.
A number of toxic effects caused by excessive
fluorides have been noted. Leone et al. (1948) found
that when 10 mg/1 of fluorides were applied to
tomato, peach, and buckwheat plants, no injury
occurred. However, at levels of 100 mg/1, the plants
were severely injured in three days. At levels of 200
mg/1, the plants were killed in a short time. In
another study (Science News Letter, 1949) using
beans, levels between 100 to 500 mg/1 inhibited
sprouting of the beans. At levels of 1000 mg/1 the
growth of the beans were markedly stunted. Prince et
al. (1949) in other studies on buckwheat found that
at levels of 180 mg/1 no injury occurred at pH over
5.5. This result agrees with the results arrived at by
Hurd-Karrer (1950). However, when the concentra-
tion was increased to 360 mg/1 both peach and
buckwheat were injured even at a pH of 6.5.
Brewer et al. (1959) used treatments of
hydrogen fluoride at rates of 0, 25, and 100 ppm on
four naval orange trees. All trees were 4 years old. All
four trees receiving 100 ppm wilted within 24 hours
after the application. Wilting was followed by com-
plete defoliation. Root examination revealed a com-
plete coverage of the roots by a slimy, gelatinous
film. The film proved to be mainly calcium, phos-
phate, and fluoride ions. The trees were so badly
damaged they were discarded. The other two treat-
ments were continued for 18 months. During this
time, the trees treated with 25 ppm became progres-
sively less vigorous than the control trees. Spring leaf
drop was also more severe. The foliage also became
increasingly sparse. Tests run on the fruit showed the
25 ppm trees to be vastly inferior both in quantity
and quality.
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Separation of Algae Cells from Wastewater Lagoon Effluents 157
McNulty and Newman (1961) used concentra-
tions of 1.31 x 10"2M sodium fluoride and found a
definite reduction in the amount of chlorophyll in
bush beans. The carotenes of these plants were also
reduced. Chang (1968) found that fluoride in con-
centrations of 5 x lO^M and 1 x 10"3M suppressed
the growth rate of com seedling roots by about 20
percent and 40 percent respectively. Chang also
pointed out that fluoride is known to act as an
enzyme inhibitor.
Iron
Iron was demonstrated to be an essential
nutrient over a century ago. Griss (as cited by
Wallihan, 1966) found that foliar application of iron
to chlorotic grapevines was very beneficial. Iron
toxicity has not occurred to any great degree under
natural conditions.
The most common symptom of iron deficiency
is chlorosis which is a reduced concentration of
chlorophyll in green plants. The addition of inorganic
iron salts generally produces little or no effect
because such compounds are quickly rendered in-
soluble in alkaline soils. This would also explain why
problems of toxicity have not occurred under natural
conditions.
Lead
Lead is not considered an essential plant nutri-
ent although there is evidence of some small
beneficial effects. Toxicity results for lead have been
somewhat contradictory. Klintworth (1952) stated
that lead is harmful to plants at all concentrations.
On the other hand, Frear (no date) added lead nitrate
to oats and potatoes at concentrations of 1.5 to 25.0
mg/1 and got stimulation effects. When he increased
the dosage to 50.0 mg/1, all plants died within a week.
Hewitt (1953) found that when sugar beets were
grown in a sand culture, the beets showed a slight
injury with a nutrient solution containing 51.8 mg/1
of lead.
Hooper (1937) found that when dwarf French
beans were grown in a nutrient culture containing 30
ppm lead in the form of lead sulphate, the plants
suffered no apparent damage. In a spraying experi-
ment, lead spray again was found not to harm the
plants other than by spraying heavily enough to
physically block the stomates.
Magnesium
Magnesium was found to be an essential nutri-
ent around the turn of the century by Pfeffer (as
cited by Embleton, 1966). A few years later, Meyer
and Anderson (1939) affirmed this conclusion.
Studies during this period also indicated possible
toxicity problems associated with excess magnesium.
Reports of magnesium toxicity seem to indicate
the problem is one of imbalance with one or more
other elements. These problems could perhaps be
overcome by increasing the level of the particular
element or elements without increasing the mag-
nesium level (Embleton, 1966). This presumes that
by increasing the other element levels, the problem is
not merely shifted but rather solved. Each case would
require individual analysis.
Garner et al. (1930) showed that soils low in
calcium which are given applications of magnesium
may produce toxic effects. Kelley (1948) found that
when a soil had more than 90 percent of the cation
exchange capacity saturated with magnesium, the soil
was almost totally unproductive. Gauch and Wadleigh
(1944) found that concentrations of 3000 to 5000
mg/1 of MgCl2 and MgS04 were toxic to bean plants.
Magnesium and calcium ions in irrigation water
tend to keep soil permeable and in good tilth. (See
Water for Irrigation Use, 1951.) This is expected
because the SAR is inversely proportional to the
concentrations of these two ions. More will be said in
the section on sodium concerning this area.
Manganese
Many early researchers have shown the neces-
sity of manganese as an essential plant nutrient.
Bertrand (as cited by Labanauskas, 1966) was one of
the first to advance the idea. McHargue (1926) grew
wheat with and without manganese and found that
without manganese the wheat became chlorotic, was
stunted, and produced no seed. These effects were
absent in the wheat grown with manganese.
Further research showed that manganese in
excess quantities could cause toxic effects. Deatrick
(1919) showed that small concentrations of
manganese clearly stimulated wheat growth but as the
concentration became large, detrimental effects
appeared. Bishop (1928) working with radishes,
beans, corn, and peas found that concentrations of 5
ppm of applied manganese stimulated growth whereas
concentrations of 10 ppm or greater depressed
growth. He found radishes, however, to be better at
10 ppm and declined from that point provided the
pH was neutral rather than acidic.
Joham and Amin (1967) determined that 81
ppm of applied manganese was toxic to cotton. The
optimum level was found to be on the order of 3
ppm. Good growth and fruiting were obtained,
however, up to levels of 27 ppm.
-------
158 Gearheart and Middlebrooks
It seems that certain soil properties increase the
probability of excess manganese problems. Snider
(1943) has shown that soils that are strongly acidic
frequently have excess manganese problems. This is
because manganese is rather dependent on pH in its
availability to plants. In other studies, Fergus (1954)
showed, using French beans and peanuts, that the
amount of manganese uptake by the plants was pH
dependent. He concluded that where large amounts
of manganese were in the soil, at pH values greater
than 5, good growth could be expected. However, at
pH values less than 5, symptoms of toxicity would
probably appear. Table 6 is a portion of the data
taken during this study. The proof of the above
statements is rather obvious from the table.
Results in full agreement with Fergus' (1954)
work were published by Gupta et al. (1970). They
found that when manganese was applied to carrots at
concentrations of 1000 ppm in a soil with a pH of 5.7
or higher beneficial results occurred. These included
reduced bronzing of leaves and increased yields.
Brown et al. (1968) showed that sugar beets were
very tolerant to manganese. In one experiment, pots
of sugar beets were treated with manganese sulfate at
the rate of 650 ppm manganese with no apparent
toxic effects. As the above studies would suggest, the
pH was approximately 5.5.
Table 6. Plant growth in relation to soil pH and
manganese content of plant.
Soil pH
4.4
4.5
4.8
4.9
5.0
5.9
Plant Mn (ppm)
3000
2400
1200
800
1100
260
Plant Growth
Very poor
Poor
Fair. Some chlorosis
Good
Fair. Some chlorosis
Good
Nitrogen
Nitrogen is an essential element for plant
nutrition and the one most commonly associated
with plant health. To a large extent it controls the
growth and fruiting of most plants. One of the early
milestone pieces of work establishing the need by
plants for nitrogen was performed by Kraus and
Kraybill (1918). They found that by using nitrates
tomato plants with sufficient nitrogen nutrition did
well whereas those without nitrogen did not do well
at all. Nitrogen shortages are more likely to be a
problem than nitrogen excesses because of the high
mobility of the element and its compounds. Short-
ages result in a reduction of chlorophyll resulting in a
loss of green color.
Nitrogen excesses can cause several kinds of
problems. Embleton et al. (1959) using sulfate of
ammonia for 3 pounds nitrogen found that plants
become highly vegetative resulting in yield reduc-
tions. Clements (1958) found that excess nitrogen
reduced sugar production in sugar cane. In other
studies (Jones and Embleton, 1959; Reuther et al.,
1958) using urea and different nitrates, the quality of
different fruits was found to be impaired. In excess,
nitrogen can also add to the salinity of the soil. This
has been confirmed by Pratt et al. (1959). Their
nitrogen sources included urea, manure, dried blood,
various nitrates, and ammonium sulfate. Excess
nitrates tend to reduce soil permeability. Nitrates
may accumulate to toxic levels but their effect is
usually osmotic (Thorne and Peterson, 1949).
All soils will become deficient in nitrogen in
time if there is no replenishing of the nitrogen using
some type of fertilization program. Soils especially
subject to deficiency, however, are sandy soils subject
to high rainfall causing leaching and soils low in
organic matter.
Zanoni et al. (1967) performed studies showing
that if carbohydrate reserves are depleted to low
levels in response to higher soil temperatures and
these levels are further reduced by increased nitrogen
levels, grasses appear to be more susceptible to injury
from disease. This happens because at temperatures
greater than 60 °F, top-growth is stimulated thus
drawing on the root reserves. Therefore excess nitro-
gen during warm weather can indirectly cause injury
by increasing greatly the disease potential.
Ford et al. (1957) using NH4N03 showed that
over fertilization with nitrogen can reduce the con-
centration of feeder roots in the principal rooting
zone of citrus trees on sandy soil. Neither the time of
application nor the fertilizer ratio was a factor in the
shift in root concentration associated with high
nitrogen. Treatments were initially 0.6, 1.2, and 2.4
pounds of nitrogen per tree per year. This was
gradually increased to 0.87, 1.75, and 3.5 pounds as
the trees grew.
Phosphorus
Phosphorus was established as an essential
nutrient in 1839 and 1840 by Liebig in Germany and
Laws in England, respectively. (See Bingham, 1966.)
Along with nitrogen and potassium, phosphorus is
quite commonly supplied to the plant by application
of commercial fertilizer. Phosphorus ties up in the
soil readily and therefore only a small fraction of the
phosphorus in the soil is available for plant use.
Acidification of the soil will help to make phosphorus
more available to the plant.
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Separation of Algae Cells from Wastewater Lagoon Effluents 159
The soils most likely deficient in phosphorus
are highly weathered soils, calcareous soils, and peat
and muck soils. Highly weathered soils are usually
acidic and often deficient in available phosphorus.
Calcareous soils may have a large total phosphorus
but the high pH due to the calcium makes the
phosphorus mostly unavailable. Peat and muck soils
often respond well to phosphorus fertilization.
Cannell et al. (1960) performed studies on
tomato plants and found that phosphorus applica-
tions of 2,10, 26, and 50 grams of CafHjPO^-HjO
per 12.5 kg of soil tended to decrease the adverse
effect of soil suction. This resulted in larger and
greener plants. These experiments were conducted on
three soil types, acidic, moderately acidic, and
alkaline. The authors suggest that perhaps phosphorus
in the form used lowered the pH and made certain
ions more available to the plants, i.e., became more
soluble. They cited manganese and magnesium as
examples.
A number of problems resulting from
phosphorus toxicity studies have been noted. Rossiter
(1952) found that the nodulation of legumes was
reduced. Bingham and Garber (1960) have shown a
phosphorus-copper antagonism, and Loneragan
(1950) presented evidence for a phosphorus-zinc
antagonism. Phosphorus-iron antagonisms were dis-
cussed by Brown et al. (1968). In many cases, the bad
effects of phosphorus in view of the antagonisms
mentioned above would appear to be indirect. These
interactions are generally more readily produced in
acid soils.
Bingham (1966) found that with a water
soluble concentration of 20 to 100 ppm or more of
phosphorus, copper deficiency was induced in citrus
seedlings by high phosphate additions. He suggests
that 40 to 80 pounds of P205 per acre be used on
small grains and 60 to 120 pounds of P205 per acre
on vegetables. Alfalfa requires high rates, from 160 to
320 pounds of P205 per acre. Where needed, citrus
should initially receive 4 to 5 pounds of P2Os per
tree and a maintenance amount of 1 to 2 pounds per
tree every few years.
Generally when phosphates occur in irrigation
waters, they offer beneficial fertilizing effects (Joshi,
1945). Blueberry plants grown in nutrient water of
low phosphate content (1 to 5 mg/1) showed
symptoms of phosphate deficiency. When the con-
centration was increased to 60 mg/1, signs of incipient
iron chlorosis appeared. Phosphorus seems to reduce
the amount of available inorganic iron thereby
producing the observed chlorosis (Holmes, 1960).
Potassium
Potassium was established as an essential nutri-
ent over one hundred years ago by Birner and
Lucanus (Ulrich and Ohki, 1966). Using oats, they
found that potassium was essential to flowering and
could not be replaced by any metal of the same
grouping. Potassium problems generally occur as
deficiencies rather than as excesses. The reason is that
both exchangeable and non-exchangeable potassium
are fixed in the soils. There are some indications that
potassium may cause deficiencies of other nutrients.
Reuther and Smith (1954) for instance suggested that
the absorption of zinc and iron by some plants may
be adversely affected by excesses of potassium.
Potassium deficiencies will manifest themselves as
interveinal chlorosis near the margins progressing to
what is termed leaf scorch. Table 7 (Ulrich and Ohki,
1966) shows several crops with values of potassium
found to be minimum levels. These values were
established by finding the point at which potassium
fertilization no longer provided significant response.
Potassium, while essential for plant growth,
must be maintained in proper balance to other
nutrients such as phosphorus (Wilcox, 1948). In
another study (Water for Irrigation Use, 1951), it was
found that potassium in irrigation water can act on
soils somewhat like sodium only it is less harmful.
Table 7. Some exchangeable potassium levels below
which responses to potassium fertilization
have been reported (Ulrich and Ohki, 1966).
Plant
Pounds of Exchangeable
Potassium (K) Per Acre
of Soil3
Alfalfa
Corn
Cotton
Field crops
Grape
Pineapple
Potato
Sugar cane
Tobacco
80
160
180
155
83
200
150
185
120
200
200
136
156
140-375
220
150
180
200
190
"Basis: 2,000,000 pounds of soil per acre.
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160
Gearheart and Middlebrooks
Salinity
Increased salinity causes problems by increasing
the osmotic pressure of the soil for water. As salinity
increases, the plant has a more difficult time obtain-
ing water from the soil. The relationship expressing
total soil suction on a plant is
TSS = MS + SS
where TSS is the total soil suction withholding water
from the plant, MS is the matric suction or the
physical attraction of soil particles for water, and SS
is the osmotic pressure due to salinity. As water is
lost through evapotranspiration, the salt concentra-
tion builds up rapidly causing the term SS to become
increasingly important. The matric suction increases
exponentially as water is lost. The combined effect of
the two factors can cause critical conditions for soil
water availability. (See Table 8 for general guidelines
for salinity in irrigation water.)
Plants react differently to salinity problems
depending on the growth stage at which salinity
becomes a problem. A study (Lunin, 1963) was
conducted showing the response of beets to salinity
at the seedling stage and at 2 and 4 weeks of
maturity. Both the roots and the top growth were
studied. The results indicated tops were affected
about the same. Roots, however, were highly
dependent on the stage of plant growth.
Climatic factors such as wind and temperature
are important in determining evapotranspiration rates
which relate back to osmotic pressure. Magistad et al.
(1943) demonstrated the effects of climate on
salinity levels. They found using cotton, alfalfa, sugar
beets, tomatoes, squash, onions, navy beans, garden
beets, and carrots that at a given salt concentration
these crops are depressed in relative yield more in
warm than in cool climates. In humid regions,
irrigation water is used to supplement rainfall. There-
fore a given water will be less likely to cause salinity
problems. This is true because salt accumulation is a
function of the salt concentration of the irrigation
water, evapotranspiration, drainage and leaching, and
the amounts of water applied and received as
precipitation.
Leaching is the best method of controlling the
salinity problem. Adequate leaching depends on a
number of factors. First, the drainage must be
sufficient to wash the salts below the root zone.
Otherwise root systems will be subjected to the
problems of osmotic pressure and not take in
sufficient water. Another factor of equal importance
is the proper amount of water for leaching. Not
enough will leave the salinity problem only partially
solved while too much will clog the pore spaces of the
soil and displace the oxygen in the soil. When this
condition exists for a prolonged period of time, plant
roots may actually rot away killing the plant. During
a field trip a row of trees was pointed out by the field
trip leader, which due to excess wetness of the root
zone, had nearly died. The problem was determined
and the appropriate action executed preventing the
loss of the trees.
Saline waters must be used in greater amounts
than non-saline waters because more of the saline
water must pass beyond the root zone than that of
the non-saline water. When saline water is being
considered for irrigation, the individual making the
decision should only consider well drained soils.
In a study performed by Robinson et al.
(1968), sprinklers were shown to be more effective in
the removal of soil salts. The water used was from the
Colorado River with a salinity of approximately 12
meq/1. They found that it was necessary to sprinkle
more frequently than usual to avoid leaf tip burn due
to salt accumulation. They used clay and sandy clay
loam soils and grew sugar beets, cabbage, carrots,
onions, wheat, barley, safflower, and flax. Under
these conditions they were able to successfully grow
these crops. Peterson (1968) warns against sprinkler
use however. He points out that water applied by
sprinklers may cause problems which would not
occur using surface application. Salt buildups can
occur causing tip burn, marginal leaf burn, or even
defoliation of sensitive plants.
Bernstein (1965) pointed out that most fruit
crops are more sensitive to salinity than are field,
forage, or vegetable crops. He also pointed out the
difference in sensitivity of the plant to salinity at
different stages of growth. This is in agreement with
Lunin et al. (1963).
Table 8. General guidelines for salinity in irrigation water.
Classification
Water for which no detrimental effects are usually noticed
Water that can have detrimental effects on sensitive crops
Water that can have adverse effects on many crops, requiring careful
management practices
Water that can be used for tolerant plants on permeable soils with careful
management practices
TDS (mg/1)
500
500-1,000
1,000-2,000
2,000-5,000
EC (mmhos/cm)
0.75
0.75-1.50
1.50-3.00
3.00-7.50
Source: National Academy of Science-National Academy of Engineering, Environmental Study Board, ad hoc Committee on
Water Quality Criteria 1972: Water Quality Criteria 1972, U.S. Government Printing Office (in press).
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 161
Werkhoven et al. (1966) found that deciduous
trees were more salt tolerant than the coniferous
species. In terms of survival, an ECe value of between
7 and 10 mmhos appeared to be critical for caragana
and elm in a soil with a moisture content of about
midway between the wilting point and field capacity.
The corresponding values for spruce and pine were
closer to 4 and 6 mmhos respectively. Seedling
survival was markedly improved by maintaining the
soil moisture level at field capacity. Emergence
seemed to improve with some salinity, but survival
Was definitely adversely affected by the salinity.
Table 9 (Eaton, 1939) gives suggested salt
tolerances for a number of crops. The table is based
on the criteria of the relative yield of the crop on a
saline soil as compared with its yield on a non-saline
soil under similar growing conditions. The table
displays the crops in columns with the most tolerant
crop at the top and the least tolerant crop at the
bottom. The values of ECe given represent the levels
of salinity at which a 50 percent decrease in yield
would be expected compared to non-saline soils
under similar growing conditions. Of course climatic
conditions may greatly influence plant reactions
compared to these suggested limits.
Table 9. Relative tolerance of crop plants to salt, list-
ed in decreasing order of tolerance (Eaton,
1939).a
Table 9. Continued.
High Salt
Tolerance
ECeX103 = 12
Garden beets
Kale
Asparagus
Spinach
ECeX103 = 10
High Salt
Tolerance
ECeX103=16
Barley (grain)
Sugar beet
Vegetable Crops
Medium Salt
Tolerance
ECeX103 = 10
Tomato
Broccoli
Cabbage
Bell pepper
Cauliflower
Lettuce
Sweet corn
Potatoes (White
Rose)
Carrot
Onion
Peas
Squash
Cucumber
ECeX103=4
Field Crops
Medium Salt
Tolerance
ECeX103 = 10
Rye (grain)
Wheat (grain)
Low Salt
Tolerance
ECeX103=4
Radish
Celery
Green beans
ECeX103=3
Low Salt
Tolerance
ECeX103=4
Field beans '
Rape
Cotton
ECeX103 = 10
High Salt
Tolerance
EQX103 = 18
Alkali sacaton
Saltgrass
Nuttall alkali-
grass
Bermuda grass
Rhodes grass
Rescue grass
Canada wildrye
Western wheat-
grass
Barley (hay)
Oats (grain)
Rice
Sorghum (grain)
Corn (field)
Flax
Sunflower
Castorbeans
ECeX103=6
Forage Crops
Medium Salt
Tolerance
ECeX103 = 12
White sweet-
clover
Yellow sweet-
clover
Perennial rye-
grass
Mountain brome
Strawberry
clover
Dallis grass
Sudan grass
Hubam clover
Low Salt
Tolerance
ECeX103=4
White Dutch
clover
Meadow fox-
tail
Alsike clover
Red clover
Ladino clover
Burnet
Alfalfa (California
Bridsfoot trefoil
common)
Tall fescue
Rye (hay)
Wheat (hay)
Oats (hay)
Orchardgrass
Blue grama
Meadow fescue
Reed canary
Big trefoil
Smooth brome
Tall meadow
ECeX103 = 12
High Salt
Tolerance
Date palm
oatgrass
Cicer milkvetch
Sourclover
Sickle milkvetch
ECeX103=4
Fruit Crops
Medium Salt
Tolerance
Pomegranate
Fig
Olive
Grape
Cantaloupe
ECeX103=2
Low Salt
Tolerance
Pear
Apple
Orange
Grapefruit
Peach
Lemon
^he numbers following ECeXlO3 are the electrical
conductivity values of the saturation extract in millimhos per
centimeter at 25°C associated with 50 percent decrease in
yield.
-------
162
Gearheart and Middlebrooks
Selenium
Though some studies have shown a stimulation
of plant growth from applications of very low
concentrations of selenium (Trelease and Trelease,
1938), generally selenium is not considered beneficial
to plants. In fact, problems associated with selenium
are normally those of toxicity due to excess selenium.
The literature indicates that the primary prob-
lem of selenium is with forage crops because of the
potential poisoning of grazing animals. Trelease and
Beath (1949) have prepared a comprehensive discus-
sion of specific symptoms of selenium poisoning in
animals.
In the continental United States, selenium
producing seleniferous plants have been found only in
arid or semi-arid areas with mean annual rainfall less
than 20 inches (Trelease and Beath, 1949). Hough et
al. (1941) found 12 to 14 ppm of selenium in some
lava produced soils in Hawaii. This is the highest
selenium content encountered in soils which do not
produce a seleniferous vegetation.
Bisbjerg and Gissel-Nielsen (1969) tested a
variety of plants and found them to be Injured
significantly by applications of 2.5 ppm or higher.
The plants included in their study were clover,
lucerne, radish, black medick, white mustard,
perennial rye grass, rye, wheat, barley, and oats.
Hurd-Karrer (1935) stated that selenium injury to
plants can be reduced or prevented when the con-
centration of sulfate ion is about twelve times greater
than the selenium concentration. Table 10 (Miller,
1954) suggests tentative limits of selenium in irriga-
tion water.
Table 10. Tentative limits of selenium in water for
irrigation (Miller, 1954).
Irrigation
Class
1. Low
Selenium
(mg/1)
0.00-0.10
Remarks
No plant toxicity
2. Medium 0.11-0.20
3. High 0.21-0.50
4. Very high over 0.50
anticipated
Usable, but with possi-
ble long-term accumu-
lations under particular
conditions should be
watched
Doubtful-probable toxic
accumulation in plants
except under especially
favorable conditions
Non-usable under any
conditions
Silica
Up until recently silica was generally considered
of little importance in irrigation water (Water for
Irrigation Use, 1951). The U.S. Department of
Agriculture has recommended limits of 10 to 50 mg/1
(McKee and Wolfe, 1963).
Later studies have increased the importance of
silica however. Eaton et al. (1968) found that
magnesium in the form of silicates can be lost from
the soil by precipitation under the following condi-
tions: (1) The concentration of magnesium must be
on the order of several meq/1, and (2) there must be a
degree of alkalinity such that a part of the silicon
dioxide is ionized as silicates. They concluded that
precipitations of calcium carbonate by whatever
mechanism occurred and the associated increases in
sodium percentages provided the source of alkalinity.
Thus silica may indirectly affect the SAR of the soil
system.
Silver
Silver has not been shown to be an essential
element in the nutrition of plants. Problems of
toxicity are unlikely because of the relative in-
solubility of silver and its common compounds. The
element availability to plants is thus low. Vanselow
(1966) found that citrus leaves growing in soil to
which 75 ppm of silver as nitrate had been added
contained only 0.5 ppm. This does not seem to cause
any injury to the plant at all.
Sodium
Except for two or three plants, sodium is not
an essential nutrient for higher plants (the poisonous
weed Halogeton is one exception). However,
beneficial results have been reported. Cope et al.
(1953) have found that in some soils, sodium
applications have increased the available potassium
supply. Truog et al. (1953) found that sodium
applications to celery improved the taste and crisp-
ness markedly. In the same study, carrots exhibited
improved taste (sweeter) with sodium applications.
Sodium can also produce detrimental effects on
plants and in the soil. The sodium condition in soils
can be evaluated using the sodium-adsorption-ratio
which is expressed as
SAR =
Na+
where the ions are concentrations expressed as
milliequivalents per liter. Another means of defining
the sodium condition is the exchangeable-sodium-
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 163
percentage, abbreviated ESP. It is related to the SAR
by the following equation:
_ 100(-0.0126 + 0.01475 SAR)
ESP = 1 + (-0.0126 + 0.01475 SAR)
When 10 to 20 percent of the cation-exchange-
capacity of a soil is taken up by sodium, the soil
condition exhibits a significant deterioration (Martin
and Richards, 1959). The soil becomes very hard
physically. This condition is sometimes referred to as
alkali soil or as chemical compaction.
Sodium, in addition to affecting plants by
damaging the soil, can also affect plants directly.
Harding et al. (1958) demonstrated that certain
plants can absorb sodium through their leaves if
irrigated using sprinkler irrigation. Ehlig and Bern-
stein (1959) showed that leaves can absorb sodium
rapidly enough to cause injury to the leaves. Since
citrus trees accumulate sodium readily through their
foliage, these plants are rather sensitive to sodium
injury. In fact sufficient sodium has been absorbed by
citrus leaves from a single sprinkling of water contain-
ing 69 to 100 mg/1 of sodium to cause serious leaf
burn and defoliation (Fireman, 1958).
Sodium sensitive plants such as woody plants
may accumulate harmful levels of sodium in the
leaves when the ESP of the soil is about 5 percent.
The SAR tolerance limit for water used on fruit crops
is about 4. For nonsensitive crops where soil effects
predominate, the SAR value can be from 8 to 18
(Bernstein, 1967). Bernstein and Pearson (1956)
found that an ESP of 15 can cause nutritional
disturbances to green beans, beets, clover, and alfalfa.
Soils that are permeable often can be easily leached.
However, soils in an advanced state of sodium excess
are less permeable and consequently more difficult to
handle.
One exception to the above ESP values was
described by Werkhoven et al. (1966). They found
that safflower showed greatly increased growth as
measured by dry weight of tops when the ESP was
increased to 20 and 30 percent. ESP levels greater
than 30 percent were detrimental to both growth and
yield.
Sulfate
Sulfur has been known to be an essential
nutrient for over 100 years. Plants get sulfur from the
sulfates in the soils. Problems with sulfates usually are
more frequently associated with deficiencies rather
than excesses. Toxic effects however have been
noted.
Many areas in the world are experiencing severe
sulfur shortages. Coleman (1966) points out the
reasons for these shortages are: (1) the increasing use
of sulfur-free fertilizers, (2) the decreasing use of
sulfur as a pesticide, and (3) increasing crop yields
which require greater amounts of plant nutrients. He
also mentions the ease of sulfate leaching which
contributes to the shortage.
Deficiencies of sulfur appear visually much like
that given by nitrogen deficiency (Ergle, 1953).
However, Gilbert (1951) found that with plants in
general, the older leaves did not dry up as did those
with nitrogen deficiency. Eaton (1942) using a sand
culture with up to 250 meq/1 of substrate sulfate
found reductions in growth of several plants. Leaf
damage also was noted in sorghum and navy beans.
Figure 6 (Eaton, 1966) shows more clearly the
results. Note that concentrations of sulfate greater
than about 5 meq/1 begin to cause detrimental
effects. The rate of growth reduction does seem to
slow down at 100 meq/1 although damage is still
continuing. Scofield (1935) suggested tolerance limits
for sulfates in irrigation waters which are listed in
Table 11. These values generally agree with Eaton's
(1942) work. Hinman (1938) however, was of the
opinion that concentrations in excess of 500 mg/1
were generally hazardous. This tolerance limit is
somewhat more limiting, of course, but not greatly
so.
For further information regarding sulfur nutri-
tional requirements, see Beaton (1966). He presents a
review of sulfur needs for a rather large variety of
plants.
Table 11. Tolerance limits for sulfates in irrigation
water.
Rating
Tolerance
Excellent
Good
Permissible
Doubtful
Unsuitable
Less than 192 mg/1
192 to 336 mg/1
336 to 576 mg/1
576 to 960 mg/1
Greater than 960 mg/1
Zinc
Zinc was established in the early 1930's as an
essential nutrient for plant growth. It was widely
accepted as an essential nutrient after the work of
Sommer and Lipman (1926) and Sommer (1928). In
the former study, sunflowers and barley were shown
to suffer significant injury in the absence of zinc. The
later work increased the number of plants under
study including buckwheat, Windsor beans, and red
kidney beans for which zinc was demonstrated to be
essential.
-------
164 Gearheart and Middlebrooks
100
80 _
60 -
o
..-I
4-J
tfl
40 -
20 _
0
Bean
100
SO. - Culture Solution, meq/1
4
200
Figure 6. Growth depression of seven crops as influenced by varying sulfate concentrations.
When zinc is deficient, the plant leaves become
mottled. A rosette-type terminal growth also can
occur. The appearance is an absence of leaves on a
branch except at the end of the branch where several
leaves appear in a spray arrangement.
Zinc can also cause toxic effects. Excess zinc
commonly causes iron chlorosis. Excesses occur in
some kinds of acid peats and especially around
mining operations where seepage and dumps can
pollute the soil. In one study (McKee and Wolfe,
1963), certain concentrations of zinc in nutrient
solutions were found to be toxic to plants. These are
shown in Table 12.
Zinc deficiencies usually occur in soils that are
acid, leached, and sandy; in alkaline soils because of
decreased availability of zinc; organic soils where the
zinc is tied up in forms not available to plants; and
soils containing clays with low silica to magnesium
ratios which give rise to forms of zinc not readily
available to plants (Elgabaly, 1950).
Hunter and Vergnano (1952) found that with
10 ppm zinc in a nutrient solution, oats were normal.
At 25 ppm the plants became slightly chlorotic. At
Table 12. Some toxic levels of zinc.
Zinc Cone.
(mg/1)
Plant
25-100
Orange and mandarin seedlings
Flax
Water hyacinths
Oats
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 165
concentrations of 100 and 150 ppm, the plants were
stunted and very chlorotic, and many leaf tips were
yellow-red. Roots were normal at concentrations of
75 ppm or less, but were small at concentrations of
100 and 150 ppm.
Public health aspects
In California in 1918, regulations were in-
stituted prohibiting the use of raw sewage, septic or
Imhoff tank effluents, or water polluted by such
sewages for the irrigation of most garden truck crops
usually eaten raw by humans. For those crops that
were cooked first, these waters were permissible
provided irrigation with polluted waters was stopped
30 days prior to harvest. Exceptions to this rule were
made, such as fruit and nut trees and melons,
provided none of the fruit or vines made physical
contact with the sewage. Later, in 1933, these rules
were liberalized somewhat provided adequate dis-
infection procedures were used. This allowed the use
of these effluents on garden truck to be eaten raw.
However, the effluent quality after treatment had to
be approximately that of drinking water (Ward and
Ongerth, 1970).
In 1967, the Water Quality Control Act was
revised. It generally differentiated water reuse and
allowed standards to be set based on the intended
use. Table 13 (Ward and Ongerth, 1970) shows the
quality standards instituted for irrigation. As can be
seen from the table, the risk involved to humans
correlates closely to the severity of the requirement.
The standard for food eaten raw is that the effluent
be free of enteric viruses, at least those possible to
detect by existing methods and that the hepatitis
agent not be present.
Considerable work on this problem has also
been done in Israel (Meron et al., 1965). In 1954, the
Israel Ministry of Health published interim regula-
tions for certain restricted crops. These regulations
have been revised from time to time but include the
following "allowable" uses: (1) industrial crops unfit
for human food, such as sugar beets, cotton, and
fibres; (2) pasture, provided the animals shall not be
allowed on the field until the grass is entirely dry; (3)
grass grown for "dry" hay; (4) vegetables which are
consumed only after cooking, i.e., eggplant, potatoes,
sweet potatoes, maize, and dry onions; (5) the
following trees: citrus, banana, nut, date palms,
avocados, and all sapling nursery stock; (6) orna-
mental shrubs, plants, and flowers; (7) plants grown
for seed production only; (8) sunflowers and carobs
(St. John's bread), provided irrigation is in furrows
only; and (9) apple, pear, and plum trees, provided
irrigation is stopped at least one month before
harvesting.
Detention in any oxidation pond for 5 days
under aerobic conditions is accepted as minimum
treatment to qualify a water for the irrigation of
restricted crops. Effluent from standard secondary
treatment facilities is similarly accepted for irrigation
of these crops. After 20 days detention time in an
aerobic pond, the effluent, with chlorination, may be
used for any crop. These regulations reflect the water
and land scarcity in Israel. The health authorities
recognize they are taking calculated risks and so they
Table 13. Summary of statewide standards for the safe direct use of reclaimed wastewater for irrigation and
recreational impoundments for California (Ward and Ongerth, 1970).
Use
Irrigation
Fodder crops
Fiber crops
Seed crops
Produce eaten raw, surface irrigated
Produce eaten raw, spray irrigated
Processed produce, surface irrigated
Processed produce, spray irrigated
Landscapes, parks, etc.
Creation of impoundments
Lakes (aesthetic enjoyment only)
Restricted recreational lakes
Nonrestricted recreational lakes
Description
Primary1
X
X
X
X
of Minimum
Secondary
and
Disinfected
X
X
X
X
X
Required Wastewater Characteristics
Secondary
Coagulated,
Filteredb and
Disinfected
X
X
Coliform
MPN/lOOml
Median
(Daily Sampling)
No requirement
No requirement
No requirement
2.2
2.2
No requirement
23
23
23
2.2
2.2
aEffluent not containing more than 0.1 ml liter hr.
Affluent not containing more than 10 turbidity units.
-------
166 Gearheart and Middlebrooks
maintain careful observation of public health condi-
tions.
In 1953, a study on the bacteriological aspects
of using polluted water on vegetables was conducted
by Norman and Kabler (1953). They showed that
coliform counts on vegetables are a consequence of
the soil count and therefore of the irrigation water.
Coliform counts of leafy vegetables such as lettuce,
celery, and cabbage tend to be greater than smooth
skinned vegetables such as tomatoes and peppers. In
one test, the ratio between leafy to smooth skin was
40 to 1 using an irrigation water with the same media
coliform count for both vegetable types. Salmonella
was found in 11 of 16 irrigation water samples but in
only 1 of 7 soil samples and in none of 10 vegetable
samples. The authors pointed out that the length of
time between the last irrigation application and the
time of sample collection may be the reason for the
low Salmonella counts.
In an earlier study, Rudolfs et al. (1951)
investigated the problem using tomatoes. They
showed that contamination was independent of
height of the tomato above the ground. They also
found the contamination to be independent of
splashing from soil due to rain. The study showed
that sunshine significantly lowers coliform counts.
They found that cracked tomatoes had higher coli-
form counts than the uncracked ones. This was not
surprising in view of the work of Norman and Kabler
(1953) with leafy vegetables. One finding of the
study was particularly interesting. When coliform
suspensions were sprayed directly on the fruit, by the
end of 35 days after spraying, the fruit had levels no
higher than the control fruit. It was also shown that
Salmonella levels were down to nearly nil at the end
of 6 days as also were Shigella. Based on these
findings, the authors concluded that if sewage irriga-
tion is stopped one month before harvest, the fruit, if
eaten raw, would not be likely to transmit human
bacterial enteric diseases. They also concluded that
except for tomatoes with abnormal stem ends
(cracks, etc.), there was no material difference in
coliform counts per gram of tomato on three dif-
ferently irrigated plots; one plot was irrigated with
settled sewage concurrently with growth, one plot
was irrigated before planting only, and one was not
irrigated with sewage at all.
Up to this point one might think the problems
are minor. That in fact is not the case. Wright (1950)
found that there is evidence indicating the consump-
tion of fresh vegetables irrigated with sewage or
polluted water has caused many disease outbreaks.
Epidemics of typhoid fever and parasitic infestations
traceable to this cause have occurred in many areas of
the world including the United States. Certainly the
strict precautions observed in California seem
justified until more research can be done to better
understand the problem and to develop means to
control these problems.
Soil clogging
The phenomena of clogging is important to soil
and crop systems. Clogging resulting from the applica-
tion of sewage effluent can reduce the supply of
moisture, air, and nutrients to plants to a point where
severe crop damage can occur.
Thomas et al. (1966) used a sewage effluent
from a septic tank with a BOD5 of 87 mg/1 to treat a
sand soil. The effluent was applied daily at a rate of 5
gal/day/ft2. The sewage was applied as nearly as
possible instantaneously and then the bed allowed to
drain until the next application. Clogging occurred in
three phases. The first phase was a gradual reduction
in filtration rate; the second phase was a short period
characterized by a rapid decline in infiltration rate; in
the third phase, the infiltration rate asymptotically
approached a lower limit. Clogging was shown to be a
surface phenomena that occurred in the top 1 cm
principally, but did occur on down to 6 cm. Total
organic matter was shown to be a significant con-
tributor to clogging. The authors also suggested the
possibility that iron and phosphate may contribute to
the problem.
Jones and Taylor (1965) also found that
clogging occurred in three phases. Their phase
descriptions differ somewhat from Thomas et al.
(1966). Jones and Taylor (1965) describe the three
phases as follows: The first phase is a period in which
the conductivity declines to nearly 25 percent of its
initial value; during the second phase the hydraulic
conductivity declines slowly to nearly 10 percent of
the original value; a rather sharp drop constitutes the
third phase, and the conductivity drops to 1 or 2
percent of the initial value. Under anaerobic condi-
tions, the second phase of clogging is absent and the
first and third phases are indistinguishable. The
reason for the discrepancy in the descriptions of the
second phase is not clear, but perhaps has to do with
different soil types.
In this same study, Jones and Taylor (1965)
found that soil clogging occurs three to 10 times
faster under an anaerobic environment than under an
aerobic one. They also found that sands of high initial
hydraulic conductivity are clogged at a much slower
rate than ones of low initial conductivity.
Rather surprisingly, Avnimelech and Nevo
(1964) claimed that organic materials which de-
compose slowly do not cause biological clogging of
sands. Included in the list of organic materials that
would not induce clogging because of slow decompos-
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 167
ition was sewage sludge. This study seems in-
consistent with the well known need for periodic
resting of septic tanks. The need for scraping the tops
off sand filters would also seerrv inconsistent with this
study.
Discussion
Introduction
This section consists of a summary of the
discussion of water quality factors in relation to
specific crops. A list of crops that appear suitable for
irrigation by each effluent is also included. The list
includes only those plants specifically mentioned in
this paper. Following this is a section of case histories
to show successful utilization of sewage effluent for
irrigation.
Table 14 summarizes the results of the study of
chemical toxicities. These values represent the most
sensitive levels reported for each component. Specific
cases may be less sensitive depending on climate, soil
type, etc. These values are approximately equivalent
to levels accumulated in nature over an extended
period of time. The blank areas represent those plants
for which effects of the particular constituent were
not found reported. Table 15 is a summary of the
average concentrations of constituents for each
stabilization pond recorded. Table 16 is a table of
recommended tolerances for trace elements in irriga-
tion water.
Summary of water quality factors
From Table 14, note that concentrations of
arsenic as low as 4 ppm have caused damage to
certain plants. A value this low coupled with arsenic's
tendency to accumulate suggests close scrutiny. The
largest average value from Table 15 is 0.004 ppm
from Logan. Comparing this value to that specified in
Table 16 shows arsenic to be well within the bounds
of safety.
Table 14 shows that citrus is extremely sensi-
tive to boron and that soybeans and fruits are fairly
sensitive. Sugar beets, cotton, and turfgrass are fairly
tolerant. If the effluent is being considered for citrus,
the value from Table 16 would bar only that from
Manila. For other crops, the Manila boron level would
be acceptable.
This study did not define toxic levels of
cadmium to crops. However, comparison of Table 15
and Table 16 show that each of the effluents is within
the specified limit.
Except for citrus and perhaps fruits, the plants
mentioned in this study seem rather tolerant of
chloride. If citrus was the crop, the Manila effluent
would be the only effluent unsuitable according to
the Israeli recommendations (see chloride section).
For the other crops mentioned, chloride could be
neglected for the effluents under consideration.
A number of plants appear to be rather
sensitive to copper with citrus being extremely
sensitive. Comparing Table 15 and Table 16 shows
the copper values of the effluents to be well within
the specified limits.
This study showed that at the pH levels
attendant to the pond effluents of Table 15, extreme-
ly little if any fluoride would be taken up by the
plant and so may be disregarded in this case.
The levels of lead required for toxicity prob-
lems are rather high. The concentrations from Table
15 appear to be negligible for the plants listed.
Further comparison with Table 16 shows the con-
centrations in these effluents to be well within the
limit.
The only magnesium toxicity problem found
was with beans, and the levels required were in excess
of 3000 ppm. Table 15 shows the levels of mag-
nesium of each effluent to be at rather low levels hi
comparison.
The study showed that at the pH levels associa-
ted with these effluents, only extremely limited
amounts of manganese would be available for plant
uptake and therefore manganese would be rather
unlikely to be toxic. Also comparison of Table 15
and Table 16 shows each effluent to be well within
the specified limits.
The only nitrogen toxicity problem occurring
directly was with citrus trees. Simple calculations
showed that approximately 210,000 gallons of water
would be necessary to supply the 2.5 pounds of
nitrogen noted. The calculations used the Huntington
level of 6.36 ppm for worst case conditions. This
concentration is clearly too small to cause
detrimental effects. The indirect effect of summer
fertilization on turfgrass is not a problem. The
amount of fertilizer recommended for golf courses is
about 120 pounds/acre/year and so 3 pounds/
acre/year will have negligible effect.
The only case of phosphorus toxicity found
was for citrus. The concentration required for injury
is 20 ppm which is rather high considering how
rapidly phosphorus is tied up in the soil and
particularly at the pH levels of the effluents. These
effluents should therefore cause no toxicity problems
from phosphorus.
-------
168 Gearheart and Middlebrooks
The data given for salinity seems rather Table 16, none of the levels of selenium in the
contradictory. The most restrictive limits found were effluents exceeds the specified limit.
suggested by the U.S. Salinity Laboratory. (See
McKee and Wolfe, 1963.) By these limits Huntington The sodium concentration of the Huntington
and Manila effluents would be unsuitable. and Manila effluents could not be used for citrus if
applied by sprinkler irrigation due to damage caused
Levels of only 2.5 ppm of selenium were found by foliar absorption of the sodium. Their SAR values
to be toxic to certain plants. Comparing Table 15 and also are too high for fruits. Other than these
Table 14. Summary of chemical toxicities for certain plants.3
Component Alfalfa Barley Beans Tomatoes Potatoes Radish
Arsenic
Bicarbonate & carbonate
Boron
Cadmium
Calcium
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
Phosphorus
Potassium
Salinity (ECexl03)
Selenium
Silica
Silver
Sodium (SAR)
Sulfate
Zinc
4 4
600
3 1.5 3
805 3150 630
100
30
3000
10
16 4
2.5
15 15
480 480
600 1200 3000
1.75 2 1.5
1365
2 6.4
100
50
10
10 10 4
2.5
480
Component Turf Beets Cotton Soybeans Peas Citrus Oats
Arsenic
Bicarbonate & carbonate
Boron
Cadmium
Calcium
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
10 25 15
7.25
665 3500 1750
6.4
51.8
650 81
5
5 0.75 1.5
7.25
175
0.1 5
25
50
10
2.5No. N/
tree/year
Phosphorus 20
Potassium
Salinity (ECexl03) 18 12 16 6 10
Selenium 2.5 2.5
Silica
Silver
Sodium ESP=15 69
Sulfate 480 480 480
.Zine 3 10
Values in ppm unless otherwise specified.
-------
Separation of Algae Cells from Wastewater Lago'on Effluents 169
Table 14. Continued.
Component
Corn Carrots Wheat Safflower Fruits
Arsenic
Bicarbonate & carbonate
Boron
Cadmium
Calcium
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
Phosphorus
Potassium
Salinity (ECexl03)
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
1.5
1.5
2450
875
206
5
455
100
10 1000
10
2.5
ESP=30 SAR=4
Table IS. Average values for water quality parameters from five stabilization ponds.a
Component
Blanding
Huntington
Logan
Manila
Roosevelt
Arsenic
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
PH
Phosphorus
Potassium
Salinity (micromhos)
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
RSC (meq/1)
SAR
0
236
0.44
0
36.5
0.645
47.5
0
0.305
0.07
0.005
14
0
0.55
7.55
10.7
7.5
600
0.004
16.5
0
58.5
35
0.005
0.88
2.07
0.003
538
0.48
0.003
209
3.23
150
0.024
0.65
0.24
0.007
268
0.089
6.36
7.73
10.9
11.4
4913
0.01 1
11.57
0.01
736
2415
0.04
-23.95
7.9
0.004
342
0.27
0.002
55
8.0
47
0.01
0.27
0.15
0
37
0
2.05
8.46
5.60
9.1
648
0.005
14.1
0
35
17
0.021
-0.10
0.89
0.01
186
1.29
0.02
210
4.53
241
0.01
1.42
0.25
0
241
0.03
2.90
8.50
0.80
28
5118
0.015
3.6
0.01
826
2631
0.01
-27.3
9.16
0
379
0.72
0
45
2.6
80
0
0.49
0.40
0
49
0
0.30
8.10
0.20
14
970
0.01
24.0
0
105
141
0
-0.09
2.57
than pH and SAR values, units are mg/1 unless otherwise noted.
-------
170 Gearheart and Middlebrooks
Table 16. Trace element tolerances for irrigation
waters.
Element
For Waters Used
Continuously On
All Soil
mg/1
For Use Up To
20 Years on Fine
Textured Soils
of PH 6.0 to 8.5
mg/1
Aluminum
Arsenic
Beryllium
Boron
Cadmium
Chromium
Cobalt
Copper
Fluoride
Iron
Lead
Lithium
Manganese
Molybdenum
Nickel
Selenium
Vanadium
Zinc
5.0
0.10
0.10
0.75
0.010
0.10
0.050
0.20
1.0
5.0
5.0
2.5b
0.20
0.010
0.20
0.020
0.10
2.0
20.0
2.0
0.50
2.0-10.0
0.050
1.0
5.0
5.0
15.0
20.0
10.0
2.5b
10.0
0.05 Oc
2.0
0.020
1.0
10.0
These levels will normally not adversely affect plants
or soils. No data available for Mercury, Silver, Tin, Titanium,
Tungsten.
Recommended maximum concentration for irrigat-
ing citrus is 0.075 mg/1.
cFor only acid fine textured soils or acid soils with
relatively high iron oxide contents.
Source: Above data based primarily on "Water Quality
Qiteria 1972," National Academy of Science-National
Academy of Engineering, Environmental Study Board, ad hoc
Committee on Water Quality Criteria, U.S. Government
Printing Office (in press).
exceptions, the SAR values are suitable for most
crops.
Table 11 grades generally unsuitable, concentra-
tions of sulfate in excess of 576 ppm. Huntingdon and
Manila effluents are totally unsuitable by this
standard. The other three effluents rate excellent by
the criteria of Table 11.
Zinc levels are sensitive for citrus fruits and so
should be checked. Comparison of Table 15 and
Table 16 show that each effluent is easily within the
specified limit.
Review of Table 15 shows that the criteria of
Wilcox et al. (1954) for residual sodium carbonate is
easily met. Therefore the bicarbonate/carbonate con-
centration does not constitute a problem.
Iron, potassium, silica, and silver were found to
produce no direct toxic effects. Under certain condi-
tions, however, silica can act to increase the SAR
value.
Table 17 shows the effluents and their sug-
gested uses for certain crops. The X's indicate
permissible usage. These decisions were based on
undiluted effluents. If sufficient dilution were used,
those cases which are rejected could become usable.
Two ponds, Huntington and Manila, are not recom-
mended for any crop. Both effluents have conduc-
tivity values and sulfate concentrations that greatly
exceed the recommended tolerance limits. In addi-
tion, their SAR values are unsuitable for fruits.
Roosevelt's effluent is somewhat questionable for
citrus. This is because the boron concentration is at a
borderline level. Further research is necessary to
refine the results of Table 17 but it does present a
starting point.
Land requirement for
effluent discharge
Another important consideration is the amount
of land required to utilize the total effluent. Since the
irrigation requirements for a given crop vary greatly
because of differences in soil type, management
practices, topography, and climate, a more general
approach will be used to determine this question.
Table 18 (Overman, 1971) is a computation showing
the required land in acres for a given total plant
effluent at a number of application rates. For
example, if the effluent discharged was 1 mgd and the
irrigation rate required by a certain plant was 1
inch/week, then 250 acres would be required to
utilize all the effluent. If a new crop were used
requiring 2 inches/week, only 125 acres would be
needed. This is not a very large area of land and for
small communities would be rather typical.
Two implications follow from this calculation.
If disposal was the only consideration, a small pasture
or other such piece of ground would be easier to
acquire than large acreage. If on the other hand, a
large number of farmers wanted to use the discharge,
only one or two would be able to use the effluent.
The solution in this case is obvious—dilution with
their normal source of irrigation water. The cost
savings would not be as great but there would at least
be some reduction. Another advantage might occur.
If the effluent had high concentrations of certain
components, the dilution factor would assist in
making the water less hazardous. This would reduce
any fertilization benefits but the overall benefits of
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 171
Table 17. Suggested crop usage for five stabilization pond effluents.
Crop
Blanding
Huntingtona
Logan
Rejected for all crops because of high salinity and sulfate values.
Questionable because of borderline boron value.
Rejected for fruits because of high SAR value.
Manila3
Roosevelt
Alfalfa
Barley
Beans
Tomatoes
Potatoes
Radish
Turfgrass
Beets
Cotton
Soybeans
Peas
Citrus
Oats
Corn
Carrots
Wheat
Safflower
Fruits
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X c
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
b
X
X
X
X
X
X
waste disposal, less expensive irrigation water, and
reduced toxicity potential would be well worth the
loss.
Case histories
Sewage effluent has been used successfully in
many trials. Day and Tucker (1960) reported success-
ful results with small grains. They grew Arivat barley,
Palentine oats, and Ramona 50 wheat using flood
irrigation. The water used for irrigation was activated
sludge effluent and contained approximately 65
pounds nitrogen, 50 pounds P205, and 32 pounds
K20 per acre foot. Four treatments were used: (1)
Pump water with no fertilizer added;(2) pump water
with the recommended fertilizer rates (100 pounds N,
75 pounds P205, and 0 pounds K,O/acre); (3) pump
water with synthetic sewage (200 pounds N, 150
pounds P205. an^ 100 pounds K20/acre); and (4)
sewage effluent with no additional fertilizer. Results
of the experiment are shown in Table 19. Note that
the yield for oats and wheat was greater using sewage
effluent than for any other treatment. Barley did not
perform as well using sewage effluent. The authors
speculated that the greater salinity and surfactant
content may have been the reason.
Another project using sewage effluent was a
golf course in Allamuch, New Jersey (Keshen, 1971).
This course was able to obtain wastewater at no cost
Table 18. Land requirement for sewage effluent dis-
posal as irrigation water in acres (Overman,
1971).
Application
Rate
(inches/week)
J4.
1
2
3J4
7
14
28
Discharge Rate
0.1
50
25
13
7
4
2
1
1
500
250
125
72
36
18
9
, mgd
10
5000
2500 .
1250
720
360
180
90
Table 19. Results of four different treatments on
small grains.
Tons/acre
Treatment
Barley Oats Wheat
1. Pump water,
added
2. Pump water,
added
3. Pump water,
sewage
4. Sewage effl.,
fert.
no fert.
recom. fert.
synthet.
no added
2.42
5.64
7.15
5.88
2.13
2.73
4.27
6.05
2.76
5.47
5.93
6.43
-------
172 Gearheart and Middlebrooks
which resulted in a savings of nearly $21,000 a year.
They also felt that because of the nutrients in the
water, that money was being saved in decreased
commercial fertilizer needs. Thus it seems that sewage
effluent would be ideal for golf courses. If the
nitrogen concentrations were as high as 30 ppm or
greater as nitrate, there are some potential hazards
that should be considered however. Studies (Zanoni
et al., 1967) have indicated that turf should not be
fertilized during the summer. The primary reason is
that above a soil temperature of 50°F or 60°F,
nutrients are utilized by plants to promote top
growth. This causes the grass to become soft and
succulant and therefore most attractive to disease and
insects. This problem is further emphasized because
golf courses in general irrigate at night resulting in
warm, moist areas ideal for disease habitats. In
contrast, when fertilization is performed only in the
early spring and not during the summer, the grass
tops are not soft and succulant and so are much less
susceptible to insects and disease.
In addition, besides running the risk of losing
turf to insect and disease damage, the cost for
maintenance will increase because mowing would be
required more frequently and larger amounts of
pesticides would be needed. The increased usage of
pesticides would of course tend to offset the savings
in commercial fertilizer cost reductions. Then too,
this increased usage contributes more pesticides to
the ecology which has already become a major area of
concern.
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APPENDIX
Table 20. Analysis of Blanding and Roosevelt pond
effluents.*
Component
Conductivity
(jumh os/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Blanding
11/25/69
680
7.85
468
228
0
0
Til
0.38
0
40
1.1
40
0
0.55
148
0
0.01
13
0
1.0
12.6
5
0.008
16
0
37
30
0
8/19/70
520
7.25
364
160
0
0
195
0.50
0
33
0.19
55
0
0.06
144
0.14
0
15
0
0.1
8.8
10
0
17
0
80
40
0.01
Roosevelt
12/15/70
970
8.10
710
314
0
0
379
0.72
0
45
2.6
80
0
0.49
312
0.40
0
49
0
0.3
0.2
14
0.01
24
0
105
141
0
aAll units mg/1 unless otherwise specified.
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 179
Table 21. Analysis of Huntington pond effluent.3
Date of Reading
Component
Conductivity (jumhos/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
7/10/68
4790
7.55
4510
417
0.01
0
507
0.44
0
240
0.99
140
0.02
0.58
1604
0.90
0
243
0.10
0.20
5.6
15
0.01
11
0
760
2512
0
11/13/68
9800
8.3
9532
690
0
0
824
0.70
0
360
9.1
270
0.08
1.06
3200
0.10
0
559
0.18
1.00
14
14
0.02
20
.0
1700
5520
0.04
3/19/69
10200
8.1
8865
560
0.01
0
674
0.52
0
320
4.7
342
0.05
1.03
3228
0.14
0.05
590
0.09
0.70
3.1
14
0.02
10
0
1600
5680
0.20
7/21/69
850
7.2
478
288
0
0
351
0.60
0
45
0.31
50
0
0.23
244
0.20
0
32
0
35.0
27.6
11
0
11
0
60
64
0.02
11/24/69
2750
7.35
2380
382
0
0
464
0.33
0
144
0.57
80
0.02
0.78
976
0
0
150
0.01
3.3
5.4
7
0.005
9
0
330
422
0
4/14/70
3000
7.2
2532
395
0
0
480
0.28
0.01
151
0.42
80
0
0.30
954
0.20
0
140
0.10
3.5
12.4
8
0.01
8
0.01
375
1319
0.02
8/18/70
3000
8.4
2632
396
0
0
469
0.47
0.01
200
6.50
85
0
0.57
1175
0.16
0
164
0.14
0.80
7.9
11
0.01
12
0
330
1387
0
aAU units mg/1 unless otherwise specified.
-------
180 Gearheart and Middlebrooks
Table 22. Analysis of Logan pond effluent.3
Component
Conductivity (pmhos/cm)
PH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Date of Reading
9/11/68
635
8.15
420
301
0
0
361
0.29
0
57
2.8
36
0
0.19
300
0.90
0
38
0
6.9
6.2
10
0
13
0
30
17
0
1/24/69
710
7.9
430
318
0
0
384
0.26
0
59
1.7
44
0.03
0.30
310
0.10
0
40
0
3.7
1.2
10
0.01
18
0
35
21
0.12
5/21/69
710
8.25
402
271
0.02
0
324
0.24
0
57
3.2
58
0.01
0.29
271
0
0
31
0
2.8
4.7
9.0
0
13
0
37
19
0.03
9/24/69
660
8.8
424
324
0
0
369
0.27
0.005
60
12.8
43
0
0.28
320
0
0
41
0
0.7
6.2
10
0
20
0
31
15
0.01
3/11/70
510
8.9
356
262
0
0
294
0.21
0
43
12.9
42
0
0.28
260
0
0
37
0
0.2
5.5
7.0
0.01
2
0
30
17
0
6/3/70
670
7.85
442
310
0
0
375
0.31
0.01
62
1.5
50
0.01
0.29
307
0.20
0
37
0
1.7
10.7
10
0
16
0
36
14
0
11/14/70
565
8.85
396
297
0
0
336
0.26
0
58
13.1
40
0.02
0.23
292
0
0
36
0
0.2
5.3
8.0
0.02
17
0
24
14
0
aAH units mg/1 unless otherwise specified.
-------
Separation of Algae Cells from Wastewater Lagoon Effluents 181
Table 23. Analysis of Manila pond effluent.3
Component
Conductivity (fimhos/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Mtrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Date of Reading
5/27/68
5350
8.0
5575
178
0
0
215
1.2
0
265
1.2
260
0.02
1.6
1680
0.30
0
247
0
7.6
0.10
30
0.01
1.0
0
1000
3258
0.01
6/12/69
5140
9.25
4688
101
0
0
102
1.0
0
158
10.1
233
0
1.16
1285
0
0
217
0
0.4
0.2
21
0.03
0.8
0
800
2700
0
10/28/69
6760
7.4
6724
100
0.01
0
122
1.7
0
232
0.17
346
0
1.68
1892
0.80
0
319
0
1.7
0
29
0
1.0
0
1150
2450
0
3/31/70
2910
8.85
2440
196
0
0
231
0.85
0
152
4.5
111
0
1.18
905
0.06
0
128
0.20
4.0
3.6
20
0.01
11
0.01
340
1350
0
8/4/70
5050
8.7
5100
222
0
0
259
1.5
0.02
232
7.1
225
0.01
1.4
1620
0.26
0
253
0
3.0
0.8
32
0.02
5.0
0
750
2830
0
12/15/70
5500
8.6
5600
158
0
0
185
1.5
0
221
4.1
270
0.03
1.48
1710
0.10
0
282
0
0.7
0.1
35
0.02
3.0
0
915
3200
0
All units mg/1 unless otherwise specified.
Table 24. Guidelines to levels of toxic substances in drinking water for livestock.3
Constituent
Aluminum (Al)
Arsenic (As)
Beryllium (Be)
Boron (B)
Cadmium (Cd)
Chromium (Cr)
Cobalt (Co)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Upper Limit
5 mg/1
0.2 mg/1
no data
5.0 mg/1
0.05 mg/1
1.0 mg/1
1.0 mg/1
0.5 mg/1
2.0 mg/1
no data
Constituent
Lead (pb)
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nitrate & Nitrite (N03-N+N02-N)
Nitrite (N02-N)
Selenium (Se)
Vanadium (Va)
Zinc(Zn)
Total Dissolved Solids (TDS)
Upper Limit
0.1 mg/lb
no data
0.01 mg/1
0.5 mg/1
100 mg/1
10 mg/1
0.05 mg/1
0.10 mg/1
25 mg/1
10,000 mg/lc
aBased primarily on "Water Quality Criteria 1972," National Academy of Science-National Academy of Engineering,
Environmental Study Board, ad hoc Committee on Water Quality Criteria, U.S. Government Printing Office (in press).
bLead is accumulative and problems may begin at threshold value = 0.05 mg/L
cGuide to the use of saline waters for livestock and poultry.
-------
UPGRADING LAGOON TREATMENT WITH LAND APPLICATION
R. E. Thomas1
Introduction
The enactment of PL 92-500 and subsequent
actions have necessitated a critical evaluation of
processes which can be utilized to upgrade lagoon
treatment of wastewaters. Land application is an
approach which shows promise because it embodies
the principle of water reuse for conservation and
addresses the "no discharge of pollutants" goal of PL
92-500. The concept of applying lagoon effluents to
the land is not new and there are many examples of
such systems in the United States. Most of these
existing systems are located in water-short regions
and the reason for utilizing this wastewater manage-
ment technique has been the conservation of a short
water supply and/or the disposal of a pond effluent
where a surface water discharge was not convenient
or appropriate. A long history of continued use at
many locations indicates that the land application
concept has been reasonably successful in achieving
the intended goals of water conservation or con-
venient disposal in the absence of access to a suitable
surface water discharge. The existence of such sys-
tems also provides a ready laboratory for assessing the
performance of several land application alternatives
for upgrading lagoon treatment in light of the needs
of today and the future.
Upgrading of lagoons can also be achieved by
land application techniques which are not in common
use at the present time since the options available are
many. These options include addition of one of
several land application approaches or complete
replacement of the lagoon system by a land applica-
tion approach. This wide range in available options
stems from the fact that there are three basic land
application approaches which have potential for use
in the upgrading of lagoon treatment. These land
application approaches are frequently designated as
(1) crop irrigation, (2) infiltration-percolation, and
(3) overland flow. Each of these approaches has
unique characteristics for adaptation to site condi-
tions and treatment needs.
The purpose of this presentation will be to
describe the use of several of the many ways in which
IR. E. Thomas is Research Soil Scientist, Water Quality
Control Branch, Robert S. Kerr Environmental Research
Laboratory, Environmental Protection Agency, Ada,
Oklahoma.
land application approaches are or can be utilized to
upgrade lagoon treatment. The discussion will include
developing technology as well as examples of land
application approaches which have been in use for
many decades.
Some Practical Options
The terminology of "soil treatment" or perhaps
more appropriately "land application for treatment
and/or reuse" is liberally sprinkled with buzz words
such as "the living filter." This situation behooves
one who is discussing the topic to acquaint his
audience with his own terminology. I am a proponent
of the terminology base which divides land applica-
tion approaches into three classes, as follows: (1)
Crop irrigation, which is characterized by com-
paratively low application rates (less than 10 cm per
week) and emphasizes the reuse of wastewater for
beneficial growth of vegetation; (2) overland flow,
which is characterized by intermediate application
rates (7.5 to 15 cm per week) and emphasizes
treatment with an effluent discharge to surface
waters; and (3) infiltration-percolation, which is
characterized by high application rates (up to 150 cm
per week) and emphasizes treatment with un-
derground storage of the reclaimed wastewater. With
the terminology base established, some practical
options can be addressed for implementing current
land application approaches to upgrade lagoon treat-
ment. Crop irrigation as an add-on to existing systems
and infiltration-percolation as an add-on to existing
systems in this category will be discussed.
Crop irrigation following
lagoon treatment
Crop irrigation following lagoon treatment or
polishing lagoons has been practiced as a commonly
accepted waste management technique for many
decades. There are several hundred of these facilities
currently operating in the southwest and far west. It
is difficult to find a single source which identifies
most of these systems, but there are several sources
which provide information on the location, age,
design, and operating schedule for many of these
systems. Deaner (1971) reports on 132 reclamation
operations in California including identification of
the treatment processes preceding land treatment.
About 70 percent of the systems have polishing
lagoons following a variety of pretreatment processes,
183
-------
184 Thomas
some 23 percent follow activated sludge or trickling
filters with direct land application, and 7 percent
have land application following primary treatment.
Crop irrigation is practiced at about 75 percent of the
sites, while landscape irrigation or golf course irriga-
tion is practiced at 25 percent of the sites. Another
source of information on crop irrigation following
lagoon treatment is the EPA Municipal Waste In-
ventory. This source provides information on some
160 facilities with lagoon treatment followed by crop
irrigation. Sullivan, Cohn, and Baxter (1973) report
detailed information on 26 sites visited during their
survey of land application facilities. Eighteen of these
systems included oxidation ponds and crop irrigation
as the last two steps in the overall treatment process.
Three of the systems visited during this survey had
been in operation for over 50 years and an additional
11 systems had been in operation for 10 to 50 years.
Myers and Williams (1970) report on the design of
lagoon systems followed by crop irrigation in Michi-
gan. They indicate that several were in operation in
1970 and all of the 15 systems which they were
planning for construction in 1971 would involve
irrigation with the treated effluent. Dean (1974) has
surveyed the use of land application in the Rocky
Mountain-Prairie region and reports 10 facilities
where lagoon treatment is followed by land applica-
tion. One of these systems is 10 years old, while all of
the others have been placed in service since 1972.
This cursory look at current practices shows that crop
irrigation following lagoon treatment is a reality
under widely differing climatic conditions. It is
obvious that these existing systems are sources of
design information for use in other locales as well as a
ready laboratory for assessing the performance of
current designs in relation to the objectives of PL
92-500.
Design of crop irrigation systems
Myers and Williams (1970) give general applica-
tion rates ranging from 0.3 to 0.8 cm per hour
programmed to achieve weekly rates of 2.5 to 7.5 cm
and yearly rates of 125 to 250 cm. They point out
that irrigation system designs are site specific and
make the following analogy, "Just as one does not
hire a butcher when he needs a surgeon, one should
not hire a plumber when he needs a professional
irrigation engineer." Pound and Crites (1973) analyze
the data collected by Sullivan, Cohn, and Baxter
(1973) as well as information from site visits which
they conducted during their study on current design
and operating information. In their chapter on
irrigation with municipal effluents, they present
details on seven facilities with lagoon treatment and
crop irrigation as the final treatment steps. They
defined crop irrigation to include application rates of
10 cm per week or less, and divided the facilities
discussed into high irrigation (7.9 to 10.7 cm per
week), moderate irrigation (5.6 to 7.6 cm per week),
and low irrigation (0.8 to 3.8 cm per week).
Information contained in reports such as those
by Pound and Crites (1973), Myers and Williams
(1970), and Sullivan, Cohn, and Baxter (1973),
demonstrate that crop irrigation systems have been
designed to adequately fulfill a wide range of local
climatic conditions and institutional constraints. In
many instances, these existing systems have evolved
through long periods of community growth and
associated problems. Long-term experience at these
existing systems has not, as yet, generated a ready
design manual, but persons contemplating the up-
grading of lagoon treatment by addition of crop
irrigation can glean valuable design, operating, and
cost information from this reservoir of information
on existing systems.
Infiltration-percolation following
lagoon treatment
Infiltration-percolation following lagoon treat-
ment is another practice which has been widely
accepted for many decades. There are many such
systems in the United States but it is even more
difficult to identify and locate these systems than it is
to identify and locate crop irrigation systems. Poor
definition of terminology in the past has led to the
inclusion of infiltration-percolation systems under the
broad category of crop irrigation approaches. Regard-
less of this limitation, there are several sources which
indicate the extent to which the infiltration-
percolation approach has been utilized as a final step
in wastewater management. Deaner (1971) identifies
seven California systems as groundwater recharge
(infiltration-percolation) operations, two of which
include lagoon treatment prior to the recharge opera-
tion. Information from the EPA Municipal Waste
Inventory differs from Deaner's (1971) interpretation
of the use of infiltration-percolation in California. A
1972 listing from the inventory with a total of 64
California facilities (less than 50 percent of Deaner's
total) lists 21 facilities as infiltration-percolation type
systems. Discrepancies of this nature are readily
attributable to the lack of uniform definition for
terminology. Overall, the listing from the Municipal
Waste Inventory indicated that about 15 percent of
160 lagoon treatment facilities utilizing land applica-
tion were entered as infiltration-percolation systems.
Sullivan, Cohn, and Baxter (1973) noted that they
did not visit six facilities initially selected for survey
because the systems were percolation systems. Pound
and Crites (1973) noted two cropping systems with
application rates greatly exceeding their defined
upper limit of 10 cm per week for crop irrigation and
classified these systems as infiltration-percolation
systems. Only one of the infiltration-percolation
systems which they discuss in depth involves a lagoon
in the treatment process.
-------
Upgrading Lagoon Treatment with Land Application 185
Design of infiltration-percolation systems
It is obvious from the foregoing discussion that
infiltration-percolation treatment of lagoon effluents
is less common than crop irrigation with pond
effluents. Consequently, existing systems do not
provide a broad based reservoir of design, operating,
and cost information. Persons contemplating the
upgrading of lagoon treatment by addition of
infiltration-percolation treatment will find that infor-
mation from closely related studies on infiltration-
percolation of activated sludge effluents and trickling
filter effluents may be the best information available
to them. Thomas and Harlin (1972) describe some
research studies which provide quantitative data
under controlled operating conditions. Aulenbach et
al. (1973) report the results of intensive studies on a
35 year old facility in a cool, humid climate with an
application rate of about 50 cm per week. Pound and
Crites (1973) evaluate the design and management of
several operational systems with application rates
ranging from 20 to 200 cm per week.
Many reserachers are continuing the assessment
of performance by existing infiltration-percolation
systems; therefore, the research community is an
important source of recent information on system
designs and system performance.
A Developing Land Application Approach
There is a newly developing land application
approach which shows promise as a wastewater
management process for utilization on slowly perme-
able soils. This approach is the overland-flow system
which has been used with excellent results by the
food processing industry. Current research is directed
to the development of this technique for advanced
waste treatment of secondary effluents and, alter-
nately, to the development of this technique for
complete treatment of raw domestic wastewater.
Overland-flow as an add-on
to secondary treatment
Hoeppel, Hunt, and Delaney (1973) are con-
ducting studies on the use of the overland-flow
approach for advanced treatment of secondary ef-
fluents. The results of their short-term greenhouse
studies show that characteristic total nitrogen remov-
als of more than 80 percent were achieved using
secondary effluent amended with sucrose to achieve a
chemical oxygen demand of 200 mg/1 at an applica-
tion rate of 6.35 cm per week. A second experiment
with sludge amended soil versus a control sou" showed
that sludge addition neither improved nor hindered
the removal of total nitrogen. These preliminary
studies also showed that several heavy metals were
effectively removed from the wastewater as it moved
down slope.
The encouraging results of these bench-scale
studies indicate that the overland-flow technique
shows promise as an advanced waste treatment
process with low energy requirements and no addi-
tional sludge production. As such, it may be a
candidate for upgrading lagoon treatment where
additional land is available for use in the treatment
process.
Overland-flow as an alternate
to lagoon treatment
Thomas et al. (1974) are conducting studies on
the treatment of raw domestic wastewater by the
overland-flow approach. The results of 18 months of
pilot scale field studies show that the overland-flow
process produces an effluent substantially better in
quality than the effluent from an activated sludge
plant. The capability of overland-flow to maintain
this level of performance during year-round operation
at an average application rate of about 10 cm per
week indicates that total land requirements for
overland-flow treatment would be comparable to land
requirements for multiple cell lagoon systems.
The pilot-scale field study is now in its third
year and the overland-flow process continues to
produce an effluent with the following composition:
Suspended solids and biochemical oxygen demand of
less than 10 mg/1; total nitrogen ranging from 2.5
mg/1 in summer to 7 mg/1 in winter; and total
phosphorus of 4 to 5 mg/1. The total phosphorus can
be reduced to less than 1 mg/1 by addition of a
precipitant such as aluminum sulfate.
It is obvious that overland-flow is capable of
achieving advanced treatment of raw domestic sewage
on a year-round basis with favorable climatic condi-
tions. We are now initiating a full-scale (0.1 mgd)
development study to evaluate performance under
operating conditions expected for small sewage treat-
ment facilities. The results of this first full-scale study
will be complemented by similar studies under a vari-
ety of climatic conditions in order to ascertain obvi-
ous constraints due to severe winter weather and
other site specific factors.
Design of overland-flow systems
The basic design of overland-flow systems
which has been developed for treatment of food
processing wastewaters will apply to systems treating
domestic wastewaters. A soil with restricted perme-
ability is a prerequisite common to all overland-flow
systems, as is the leveling of the land to obtain
uniform and gentle slopes. Construction of inter-
ceptor terraces at about 60 m spacings and the
construction of a distribution system (usually auto-
mated) are also integral features of all overland-flow
facilities. Daily application and drying cycles with
-------
186 Thomas
regular 1- or 2-day drying cycles at 5- or 6-day
intervals will also be required to maintain a micro-
environment which maintains treatment performance
without promoting the breeding of nuisance insects.
Major questions to be elaborated regarding
technical aspects of system design are the rate of
application and constraints placed on the length of
the operational season by climatic conditions. The
need for elaborating application rates is readily
demonstrated by comparing the application rates
used in the two research studies which have been
discussed previously. Thomas et al. (1974) observed
successful treatment of raw domestic sewage at an
application rate 1.5 times as great as the application
rate that Hoeppel, Hunt, and Delaney (1973) used for
applying amended secondary effluent. The need to
ascertain the constraints imposed by subfreezing
winter temperatures are complex and many. Resolu-
tion of these constraints will require evaluation of the
overland-flow approach at many field sites with
varying climatic conditions.
Summary
Land application is a viable approach for
upgrading lagoon treatment to meet newly imposed
standards for secondary treatment. It is also a viable
approach for satisfying even more stringent require-
ments which are proposed for future implementation.
There are several land application alternatives which
can be considered, and the alternative selected will
depend largely upon local requirements and site
characteristics.
Crop irrigation is an alternative which has been
in use for many decades under a variety of climatic
conditions with a high degree of success. Existing
crop irrigation systems provide a vast reservoir of
information on design and operating experiences
which have led to problems, as well as successes. This
reservoir of information from existing systems is a
valuable resource which can be utilized by those
contemplating crop irrigation for upgrading lagoon
treatment.
Infiltration-percolation is another alternative
which has limited but widespread use for advanced
waste treatment of secondary effluents. It is more
typical for infiltration-percolation to follow activated
sludge or trickling filters as the secondary treatment
process, therefore, the reservoir of existing informa-
tion on design and operating experience following
lagoon treatment is not extensive. Information on
infiltration-percolation following other conventional
processes for achieving secondary treatment does
provide a valuable resource which can be effectively
utilized by those contemplating infiltration-
percolation for upgrading lagoon treatment.
Current research studies are exploring the
utility and practicality of utilizing other land applica-
tion alternatives for management of domestic waste-
waters. Overland-flow is a land application alternative
which is being evaluated for upgrading secondary
effluents and for complete replacement of conven-
tional secondary treatment processes. Development
of both of these approaches is at a rudimentary stage
but they show promise for successful implementation
in practical situations.
References
Aulenbach, D. B., J. G. Ferris, N. L. Clesceri, and T. J.
Tofflemire. 1973. Thirty-five years of use of a natural
sand bed for polishing a secondary treated effluent.
Rensselaer Fresh Water Institute at Lake George, FWI
Report No. 73-15, Rensselaer Polytechnic Institute,
Troy, N.Y. September. 51 p.
Dean, R. J. 1974. Land application of effluents in the rocky
mountain-prairie region. Thesis, University of
Colorado, Boulder. 152 p.
Deaner, D. G. 1971. California water reclamation sites 1971.
Bur. Sanit. Eng., State of Calif. Dept. Public Health,
Berkeley, Calif. June. 64 p.
Hoeppel, R. E., P. G. Hunt, and T. B. Delaney, Jr. 1973.
Wastewater treatment on soils of low permeability.
U.S. Army Waterways Experiment Station, Vicksburg,
Miss. Miscellaneous Paper Y-73-2, December. 85 p.
Myers, E.A., and T. C. Williams. 1970. A decade of
stabilization lagoons in Michigan with irrigation as
ultimate disposal of effluent. In: 2nd International
Symposium for Waste Treatment Lagoons, McKinney,
R. E. (ed.). University of Kansas, Lawrence. June. p.
89-92.
Pound, C. E., and R. W. Crites. 1973. Wastewater treatment
and reuse by land application, Volume II. Environ-
mental Protection Agency, Washington, D.C. Report
No. EPA-660/2-73-006b, August. 249 p.
Sullivan, R. H., M. M. Conn, and S. S. Baxter. 1973. Survey
of facilities using land application of Wastewater.
Environmental Protection Agency, Washington, D.C.
Report No. EPA-430/9-73-006, July. 377 p.
Thomas, R. E., and C. C. Harlin, Jr. 1972. Experiences with
land spreading of municipal effluents. In: Proc. IF AS
Waste Water Workshop, 1972, on Municipal Sewage
Effluent. Tampa, Florida, May 30-June 1. p. 151-164.
Thomas, R. E. et al. 1974. Feasibility of overland flow for
treatment of raw domestic wastewater. Environmental
Protection Agency, Washington, D.C. Report No. EPA
660/2-74-087. July. 30 p.
-------
LAGOON EFFLUENT SOLIDS CONTROL BY
BIOLOGICAL HARVESTING
W. R. Duffer1
Introduction
Stabilization of organic wastes in lagoons has
developed as a wastewater treatment which favors
establishment and maintenance of specific types of
organisms. Plantonic algae in combination with
aerobic bacteria are the organisms responsible for
oxidation of organic materials. Since a large propor-
tion of the organic materials are converted to
phytoplankton, suspended solids are usually present
in relatively high concentrations in lagoon effluents.
Research effort for this wastewater treatment process
has centered around design and operation practices
for improving production of algae, rather than
developing design criteria for enhancing establishment
of organisms! populations to consume the excessive
algal production.
It is the purpose of this paper to (1) review the
accomplishments of several studies oriented toward
removal of phytoplankton by other aquatic or-
ganisms, (2) identify some of the problems associated
with biological harvesting of phytoplankton, and (3)
suggest research areas which should be developed.
Suspended Solids Removal
Studies which relate to solids removal have
been conducted in both marine and freshwater. It
should be remembered at this point, however, that
the concept of control of algae by organisms in the
marine and freshwater food chains is not completely
proven and has not gained acceptance as a treatment
practice due to the uncertainties involved. Although
most of the experiments conducted in the United
States have been small scale, several have been highly
successful and will provide a sound basis for develop-
ment of applied pilot scale research efforts. In-
vestigations have centered around several types of
organisms including zooplankton, bivalve mollusks,
and fish.
1\V. R. Duffer is Research Aquatic Biologist, Water
Quality Control Branch, Robert S. Ken Environmental
Research Laboratory, Environmental Protection Agency,
Ada. Oklahoma.
Zooplankton
Several field and laboratory experiments have
been conducted which utilize the cladoceran,
Daphnia, for removing excessive algal growth. A
two-stage pond system was established at Calabasas,
California, for polishing activated sludge effluent (Las
Virgenes Municipal Water District, 1973). The shal-
low first-stage pond developed a high concentration
of phytoplankton. In the second-stage pond, which
had a water depth of about 3 meters, a population of
Daphnia pulex effectively removed the algae. The
capacity of the first stage was about three times
greater than that of the second stage and the system
was operated with about 10 days' detention in each
stage. Daphnia concentrations above 500
organisms/liter were responsible for a suspended
solids reduction of about 50 percent. A summer
decline of the Daphnia population and occasional
invasion of Daphnia or rotifers in the first-stage pond
were major problems encountered.
Aquarium experiments employing Daphnia and
Lemna cultures were conducted in Israel (Ehrlich,
1966). In one experiment, sewage stabilization pond
effluent was stored in a feeding container and allowed
to drip into nine basins at varying rates. Each basin
contained Lemna-Daphnia cultures and the periods of
detention ranged from 8 to 360 hours. Effluent from
the experimental basins was relatively clear, while
samples from the feeding container remained turbid.
In another experiment, stabilization pond effluent
was fed to four aquaria, each having a detention
period of 10 days. This test was designed to deter-
mine the relative roles of Lemna and Daphnia in the
suppression of a population of Chlorella. One unit
contained a Lemna-Daphnia culture, another Lemna
only, another Daphnia only, and the fourth was
maintained as a blank. Test results indicated that the
Lemna-Daphnia unit gave the best reduction of
Chlorella, followed by the Lemna only unit. Numbers
of Chlorella per cm3 were similar for the Daphnia
only unit and the blank following 13 days of
operation.
Results of a survey of domestic wastewater
treatment facilities in Texas utilizing ponds indicate
187
-------
188 Duffer
that occurrence of Daphnia is quite uncommon
(Dinges, 1974a). Only 29 of the 470 pond systems
support Daphnia populations. These systems, how-
ever, are noted to maintain relatively stable condi-
tions and to have clear effluents. In a discussion of
the environmental requirements of Daphnia, Dinges
and Rust (1972) conclude that photo-period is the
dominant environmental factor affecting Daphnia in
stabilization ponds. In general, population pulses in
Texas ponds appear when the period of sunlight
approaches about 10 hours per day and remain until
the period of sunlight approaches 14 hours per day.
Other environmental factors affecting pulses include
hydrogen ion concentration, presence of dissolved
oxygen, free ammonia and hydrogen sulfide.
An experimental Daphnia culture pond having a
capacity of 10,000 gallons was constructed to treat
effluent from sewage oxidation ponds at Giddings,
Texas (Dinges, 1973). The site was selected because
the ponds had a past history of producing abundant
algae and had never been known to support Daphnia
populations. The experimental pond had a surface
area of .01 acre and was operated for an 11-day
detention period. The investigation was conducted in
two phases for three months during the minimum
seasonal photo-period. The first phase was designated
to determine the effectiveness of pH control by
shading to reduce algal growth, and the second phase
evaluated pH control through chemical addition and
sulfide reduction by aeration. A continuous culture
of Daphnia was maintained during both phases and
suspended solids reductions for the stabilization pond
effluent were 86 percent and 83 percent, respectively.
Dinges (1974b) has proposed several sewage
stabilization designs for separate facilities which take
into account environmental requirements of zoo-
plankters. Design considerations include pond site
selection, construction of berms and baffles, inlet and
outlet structures, mixing and depth, substrate and pH
regulation. Culture ponds requiring rigid control and
extensive management are considered, as well as
primative installations requiring minimum regulation.
Bivalve mollusks
Both marine and freshwater species of mollusks
have been cultured to remove algae from suspension.
Corbicula, an oriental freshwater clam, has been
reported to filter in excess of 0.5 liters per day per
organism (Prokopovich, 1969). Greer and Ziebell
(1972), in studies designed for removal of ortho-
phosphate from water, utilized natural algal popula-
tions and clam filtration. Corbicula could clarify
water containing high concentrations of algae and
survive under highly enriched conditions, providing
water was circulated and temperatures maintained
below 30°C. Corbicula has a very high reproductive
capacity and does not require an obligate parasitic
stage in its life cycle.
Several laboratory experiments have been per-
formed by a group at Woods Hole Oceanographic
Institution using oysters and other marine bivalve
mollusks for removal of algae which was grown in a
combination of secondarily treated wastewater and
seawater (Rytler, 1973). These experiments were
highly successful from the standpoint of nutrient
removal, and a prototype process was developed
around the food web concept. Several growth systems
involving marine phytoplankton, oysters, deposit
feeders, and seaweed were combined in series and fed
secondarily treated wastewater diluted with filtered
seawater. Filter-feeding bivalve herbivores removed
85 percent of the algae fed to the system. In order to
determine performance of the multi-species food web
concept on a large scale, pilot plant facilities have
been designed and constructed at Woods Hole
(Huguenin, 1974).
Fish
In Asia, fish culture in highly enriched waters
has been practiced for centuries and the most
commonly cultured fish are members of the carp
family (Cyprinidoe) (Bardach et al., 1972). In China,
the most commonly cultured phytoplankton feeder is
the silver carp. The Chinese, however, usually stock
several types of fish in culture ponds. This practice
insures the most efficient use of the variety of fish
food organisms available.
The Arkansas Game and Fish Commission has
obtained the silver carp on an experimental basis and
most of the effort to date has centered around
propogation studies (Husley, 1974). State fish
hatchery personnel have successfully spawned the
silver carp and indicate that aquarium water contain-
ing high concentrations of algae could be cleared by
this plankton feeding species within 24 hours.
Hatchery biologists expect to expand their pond
culture studies to include native fish species in a
polyculture system.
Fathead minnows were stocked and success-
fully cultured in the sewage stabilization system at
Belding, Michigan (Trimberger, 1972). The system
consisted of five oxidation ponds operated in a series.
Minnows were placed in the last three ponds of the
series at stocking rates less than one pound per acre.
Six months after stocking, the fish were harvested,
yielding 378 pounds per acre. Ponds stocked with
minnows were noted to be less turbid than the other
oxidation ponds.
A field study designed for removal of algae
from sewage oxidation ponds through the food chain
-------
Lagoon Effluent Solids Control by Biological Harvesting 189
mechnanism was conducted by the Oklahoma State
Department of Health (Coleman et al., 1974). A
six-cell lagoon system receiving raw domestic waste-
water was operated in series with the first two cells
being aerated. Fingerling channel catfish were stocked
in Cells 3 and 4, while golden shiner adults were
stocked in Cells 5 and 6. Fathead minnows and
Talapia nilotica were also placed in the third cell.
Lagoons were contaminated with the black bullhead,
green sunfish, and mosquito fish already present in
the system. Fish biomass estimates were based on
seine hauls from a closed area of each cell. Talapia
biomass increased from an initial 4 to 163 pounds
during a period of about four months. Golden shiner
minnow biomass increased from 85 to 535 pounds
during a period of about four months. The biomass of
channel catfish increased from an initial 600 to an
estimated 4,400 pounds in a period of about eight
weeks. Mean values of weekly analyses for suspended
solids during the 4-month period of fish culture
indicate a general decrease through the pond series
with an 83 percent solids reduction by comparing the
effluents of Ponds 2 and 6.
Problem Areas and Research Needs
Based on the number of successful investiga-
tions utilizing a variety of organisms for removal of
high concentrations of algae, the food chain concept
appears to be a basically sound approach for develop-
ment of a mechanism for solids control in sewage
oxidation ponds. However, it should be pointed out
that the greatest effort to present has consisted of
either small-scale laboratory experiments or descrip-
tive studies in large systems where only limited
control was possible. Carefully controlled pilot-scale
experiments are required prior to full-scale demon-
strations in order to assure research flexibility for
determining design criteria and management ap-
proaches.
Specific areas which require additional research
effort for development of biological control of lagoon
solids are:
1. Extent of selective solids uptake by vari-
ous species of herbivores, as well as the
mechanisms involved, should be estab-
lished.
2. A greater number of herbivore species
should be examined to determine the
compatibility of their environmental re-
quirements with wastewater effluents.
3. The science of ecology must be applied to
increase the efficiency and stability of
biological control systems. Engineering
design parameters should be couched in
terms of the multi-species approach and
polyculture of organisms rather than the
capability of single species.
4. Seasonal aspects of treatment culture
units and life stage requirements of
organisms must be taken into account.
5. Values must be assigned to productivity
of culture systems in terms of potential
for use in aquaculture and commercial
markets.
6. Potential for problems to areas such as
recreation, agriculture, and aquaculture,
must be determined for introduction of
exotic species such as Corbicula or the
silver carp.
References
Bardach, J. E., J. H. Rytler, and W. O. McLarney. 1972.
Aquaculture, the farming and husbandry of freshwater
and marine organisms. New York, John Wiley & Sons.
868 p.
Coleman, M. S., J. P. Henderson, H. G. Chichester, and R. L.
Carpenter. 1974. Aquacultuie as a means to achieve
effluent standards. In: Wastewater Use in the Produc-
tion of Food and Fiber-Proceedings. Environmental
Protection Agency, Washington, D.C. Report No. EPA-
660/2-74-041, p. 199-214.
Dinges, R. 1973. Ecology of Daphnia in stabilization ponds.
Texas State Department of Health Publication. 155 p.
Dinges, R. 1974a. The availability of Daphnia for water
quality improvement and as an animal food source. In:
Wastewater Use in the Production of Food and
Fiber-Proceedings. Environmental Protection Agency,
Washington, D.C. Report No. EPA-660/2-74-041, June.
p. 142-161.
Dinges, R. 1974b. Biological considerations in stabilization
pond design. Presented at 56th Texas Water Utilities
Short School, Texas A&M University. 17 p.
Dinges, R., and A. Rust. 1972. The role of Daphnia in
wastewater oxidation ponds. Public Works, October, p.
89-91.
Ehrlich, S. 1966. Two experiments in the biological clarifica-
tion of stabilization-pond effluents. Hydrobiologia
(Israel), 27:80-90.
Greer, D. E., and C. D. Ziebell. 1972. Biological removal of
phosphates from water. J. Water Pollution Control
Federation 44(12):2342-2348.
Huguenin, J. E. 1974. Development of a marine aquaculture
research complex. Presented at Annual Meeting, Ameri-
can Society of Agricultural Engineers, Oklahoma State
University, Stillwater. Paper No. 74-5009.
-------
190 Duffer
Hulsey, A. 1974. Personal communication-private conversa-
tion, Little Rock, Arkansas.
Las Virgenes Municipal Water District, Calabasas, California.
1973. Tertiary treatment with a controlled ecological
system. Environmental Protection Agency, Washington,
D.C. Report No. EPA-660/2-73-022, December. 43 p.
Prokopovich, N. P. 1969. Deposition of clastic sediments by
clams. J. Sed. Petrol, p. 891.
Rytler, J. H. 1973. The use of flowing biological systems in
aquaculture. Sewage Treatment, Pollution Assay and
Food-Chain Studies. WHOI-73-2. (Unpublished manu-
script.)
Trimberger, J. 1972. Production of fathead minnows
(Pimephales promelas) in a municipal waste water
stabilization system. Michigan Department of Natural
Resources, Fisheries Division. (Mimeographed report.)
5 p.
-------
PROGRESS REPORT: BLUE SPRINGS LAGOON STUDY
BLUE SPRINGS, MISSOURI
C. M. Walter and S. L. Bugbee1
Introduction
Public Law 92-500, the Federal Water Pollution
Control Amendments, was enacted by Congress on
October 18, 1972. These amendments provided the
necessary regulatory environmental legislation for
controlling municipal and industrial waste sources
prior to discharge to receiving waters. The control is
exercised through the implementation of the National
Pollutant Discharge Elimination System (NPDES) as
outlined in Section 402 of the amended act. Simply
stated, the NPDES requires the issuance of permits
for every discharge to navigable waters.
These permits are written to include imple-
mentation schedules for achieving specified levels of
waste treatment and prescribed self monitoring re-
quirements. In the case of municipal waste discharge
permits, the permits require secondary treatment on
all discharge by 1977. For permit conditions,
secondary treatment is defined by concentration
limits on 5-day biochemical oxygen demand (BOD5)
and nonfilterable solids (suspended solids or NFS)
and fecal coliform densities. The limits are 30 mg/1,
30 mg/1, and 200 organisms/100 ml, respectively.
The economic base of Region VII of the
Environmental Protection Agency is primarily agricul-
tural. As a consequence, approximately 80 percent of
the waste treatment facilities are located in small
rural communities which are, for the most part,
declining in population with an attendent reduction
in resources to provide community services. In many
instances, these small towns are not constrained by
land availability and have resorted to lagoon systems
for municipal waste treatment. The towns usually
have a locker plant which does some custom
slaughtering and/or a creamery which contribute
shock loads to the sewage system. The prime question
is, will a lagoon system furnish the necessary degree
of treatment to meet the secondary criteria?
Over the past 3 years we have sampled approxi-
mately 330 lagoon systems of various sizes and
1C. M. Walter is Sanitary Engineer, and S. L. Bugbee is
Aquatic Biologist, U.S. Environmental Protection Agency,
Regional Laboratory, Region VII, Kansas City, Kansas.
configurations. This field sampling exercise has been
conducted over all seasons and is usually comprised
of one to three 24-hour composite samples of the
influent and a similar number of grab samples from
the effluent. During the same period, we have also
sampled a number of small mechanical and/or pack-
age plants. In March of this year, a summary of our
plant experience was compiled to provide a general
assessment of plant performance. These data are
shown in Table 1.
Average waste treatment performance for
BOD5 and suspended solids removal to meet
secondary treatment requirements occurred only in
three-cell lagoon systems. Average fecal coliform
densities in effluents from all systems exceeded the
secondary treatment definition limit. Since all of the
data presented were collected in a more or less
random fashion during various seasons, the resulting
averages should reflect normal operating conditions.
These data then provide a basis for developing
practical plans for upgrading waste treatment for the
immediate future.
There are many economic implications involved
in selecting waste treatment systems. One of the
prime concerns is eligibility for a Federal Construc-
tion grant under the requirements of meeting
secondary treatment. A special intensive study was
planned to evaluate seasonal performance of a three-
cell lagoon to provide data on the ability of these
systems to meet secondary treatment criteria.
The Blue Springs, Missouri, three-cell in a series
lagoon system was selected for the study. This
system, comprised of three cells with an area of 16.8,
5.0, and 1.7 hectares (41.5, 12.4, and 4.1 acres)
respectively, was designed to serve a population
equivalent of 11,000 and is now serving an estimated
12,000 to 13,000 people.
Study Description
A study plan was developed with three objec-
tives in mind:
1. Determination of the performance of a
three-cell, series operated, lagoon.
191
-------
192 Walter and Bugbee
Table 1. Treatment plant effluent data, Region VII.
Type of Plant
1 Cell
Lagoons
2 Cell
Lagoons
3 Cell
Lagoons
Activated
Sludge
Trickling
Filter
Primary
No. of Plants
33
28
9
46
178
40
BOD5
mg/1
Ave.
Range
54
17-273
48
3-133
22
9-40
40
8-180
37
20-71
165
84-315
Suspended Solids
mg/1
Ave.
Range
64
8-891
105
8-891
31
7-54
72
5-162
80
44-149
131
32-182
Fecal No./ 100 ml
Coliform
Ave.
Range
2.6 x 104
7x 102 -1.5xl05
1.2 x 10s
2x 102-8.5xl05
2.7 x 104
2x 102-2.7X104
2.2 x 105
5.2X103-2.8X105
7.6 x 105
1.7xl05-1.6xl06
4.4 x 106
5.1xl038.7xl06
2. Determination of the relative performance
of the first, second, and third cell of a three-cell
lagoon.
3. Determination of the quality of a sand
filtered lagoon effluent and the feasibility of slow
sand filtration.
In order to meet the study objectives and take
into account seasonal variations, a minimum study
period of one year was required. Field sampling was
planned quarterly during 30-day periods in winter,
spring, summer, and fall. The first two sampling
periods are complete and the third is currently in
progress. The fourth sampling period is scheduled in
October and November, 1974.
The sampling scheme selected was based on the
availability of laboratory support and the minimum
number of stations that would meet the study
objectives. The eight sampling stations used were the
raw waste at the influent wet well, the effluent from
the first, second, and third cells, and effluent from
four pilot plant sized sand filters, two each, following
the second and third cells.
Automatic compositors were used at each
station to collect 24-hour composite samples for all
analyses except biological. These samples were
analyzed under the scheme shown in Table 2.
In addition, daily flow measurements were
taken from the influent totalizer and from the
continuous recording of head measurements on the
Cipolletti Weir in the third cell effluent channel. Two
types of sand filters were used at each location. The
first filter utilized a prepared sand with an effective
size of 0.3 mm and a uniformity coefficient of 2.5,
while the second filter was filled with river-run sand
with an effective size and uniformity coefficient of
0.22 mm and 3.5, respectively. After the winter
study, all sand filters were converted to prepared sand
because the river-run sand filters plugged throughout
their entire depth necessitating complete replace-
ment. The sand filters were constructed out of barrels
welded together and had a depth of 1.07 meters (42
in) of sand over 0.30 meters (12 in) of coarse gravel
underdrain. They were considered plugged when the
head loss through the filter exceeded 1.22 meters (4
ft).
Results
Table 3 presents a summary of analytical results
for the winter sampling period. The influent data are
divided in two sections with significantly different
results. The reason for the discrepancy is due to a
change in type of automatic compositor used on the
influent. Initially a peristaltic pump driven com-
positor was used. Equipment failure necessitated a
change and a vacuum activated compositor was
substituted. The vacuum operation results in a collec-
-------
Blue Springs Lagoon Study, Blue Springs, Michigan 193
tion of a greater proportion of solids and also affects
the concentration of other parameters which can be
present in either dissolved or particulate form. The
variation between compositors has* been documented
by Harris and Keffer (1974). For evaluation between
cells and overall performance, the data collected
between February 3 to 20, 1974, should be utilized.
During the winter period 84 percent of the
BOD5 removal occurred in Cell 1. The second and
third cells provided essentially no additional BOD5
removal, but were effective in reducing concentra-
tions of COD and NFS by 32 and 23 percent,
respectively. The influent fecal coliform count was
decreased from 475,000 to 22,000 organisms/100 ml
Table 2. Laboratory analyses, Blue Springs Lagoon Study.
Daily 24 Hour Composite
24 Hour Composite Taken 7 of
the 30 Day Period
Miscellaneous
5 Day BOD @ 20°C
COD
TOC
Non-filterable Solids
Volatile Solids
Total Phosphorus
Ammonia Nitrogen
Nitrite-Nitrate Nitrogen
Total Kjeldahl Nitrogen
Turbidity
Alkalinity
pH
Specific Conductance
(A) Non-filtered
2,5, 10, 20,35, 56 Day BOD
Nickel
Lead
Cadmium
Zinc
Copper
Chromium
(B) Filtered (0.45 u)
5 Day BOD
COD
TOC
Total Volatile Solids
Total Phosphorus
Ammonia Nitrogen
Total Kjeldahl Nitrogen
(A) Daily
Total Coliform
Fecal Coliform
(B) Weekly
Phytoplankton enumeration and
identification
Chlorophyll a
Table 3. Summary of operating data, Blue Springs lagoon system, average values, January 22 to February 20,
Sampling
Station
Influent3
Wet Well
1/22-2/2/74
Influent
Wet Well
2/3-2/20/74
Effluent
Celll
Effluent
Cell 2
Effluent
Cell 3
Flow
mgd
3.0
1.48
2.46
Temp.
°C
12.7
11.6
4.5
4.1
3.7
PH
7.57
6.35
7.39
7.34
7.27
BOD,;
mg/I
42.5
176
28.1
27.9
26.8
COD
mg/1
171
900
119
89
81
NFS
mg/1
63
307
17
13
13
TotP
mg/1
3.95
8.75
6.66
6.58
6.93
NH3-N
mg/1
3.53
10.67
10.25
10.63
11.05
NCyNO^N
mg/1
1.71
0.12
0.10
0.10
0.10
TKN
mg/1
6.91
15.94
12.63
12.57
12.86
TotN
mg/1
862
16.06
12.73
12.67
12.96
Fecal
Coliform
Organ/
100ml
420 x 103
475 x 10 3
69.7 x 103
29.9 x 103
22 x 103
Automatic compositor changed on 2/02/74 from ISCO 1391 to QCEC CVE.
ISCO operation is by peristaltic pump, CVE by vacuum. Experience to date shows vacuum operation collects more solids.
-------
194 Walter and Bugbee
in the final effluent. The data demonstrates the
ability of a three cell system to meet secondary
treatment limits for BOD5 and NFS, but shows the
difficulty in meeting fecal coliform requirements
without disinfection.
The April and May, 1974 data are summarized
in Table 4. With increasing water temperatures, the
overall system efficiency for BOD5 removal was 88
percent. The final effluent concentration of BOD.
was 23.2 mg/1, well below the 30 mg/1 secondary
treatment limit. The concentration of NFS (Table 4)
also met secondary treatment criteria. The fecal
coliform count in the final effluent (Table 4) was still
in excess of prescribed limits.
Data from winter and spring sand filter opera-
tion are presented in Tables 5 and 6. The winter
operation was conducted in a heated shelter which
may have affected the results. Between the winter
and spring sampling periods, the two filters contain-
ing river-run sand were changed to prepared sand.
Until the summer and fall data are complete, no
attempt will be made to correlate application rates
and filter efficiency.
Phytoplankton and chlorophyll a data for
winter (January), Spring (April), and Summer
(August) sampling periods are summarized in Tables 7
through 9.
Table 4. Summary of operating data, Blue Springs lagoon system, average values, April 22 to May 24, 1974.
Sampling
Station
Influent
Wet Well
Effluent
Celll
Effluent
Cell 2
Effluent
Cell3
Flow
mgd
1.76
1.83
Temp.
°C
13.3
18.2
18.7
20.1
pH
7.14
7.51
7.55
7.62
BOD5
mg/1
196
61.2
30.9
23.2
COD
mg/1
621
208
124
94
NFS
mg/1
557
106
43
26
TotP
mg/1
8.93
8.44
8.59
8.70
NH3-N
mg/1
11.03
6.78
7.30
8.23
N02-NO3-N
mg/1
0.41
0.07
0.06
0.05
TKN
mg/1
19.25
16.77
13.00
12.45
TotN
mg/1
19.66
16.84
13.06
12.50
Fecal
Coliform
Organ/
100ml
534 xlO3
14.1 xlO3
15 x 103
3.8x 103
Table 5. Summary of operating data, Blue Springs lagoon system, Cell 2 and Cell 3 sand filters, average values,
January 22 to February 20,1974.
Sampling
Station
Prep. Sand
Cell2,Filt.A
River-run Sand
Cell2,Filt.B
Prep. Sand
Cell 3, Filt. C
River-run Sand
Cell 3, Filt. D
Flow
gpma
0.50
0.50
0.50
0.50
Temp.
°C
PH
7.26
7.30
7.29
7.32
BOD5
mg/1
23.2
20.3
25.0
19.8
COD
mg/1
69
61
82
62
NFS
mg/1
10
9
9
10
TotP
mg/1
6.49
6.50
6.69
6.67
NH3-N
mg/1
11.00
10.76
11.05
11.01
N02-N03-N
mg/1
0.10
0.10
0.10
0.10
TKN
mg/1
12.82
12.40
12.90
12.73
TotN
mg/1
12.92
12.50
13.00
12.83
Fecal
Coliform
Organ/
100ml
26xl03
21X103
19xl03
ISxlO3
How applied at rate of 10 mgad-no plugging.
-------
Blue Springs Lagoon Study, Blue Springs, Michigan 195
The winter season phytoplankton population
was less than 5,000 cells/ml in each of the three cells.
Correspondingly, the concentration of chlorophyll a
in each of the cells was less than one microgram per
cubic meter (yu g/m3). The predominate algae forms
during this period were Oscillatoria, a filamentous
blue-green, and Chlamydomonas, a green flagellate.
Filtering the effluent from Cell 2 significantly
altered the phytoplankton community structure.
Chlamydomonas, which represented only 28 percent
of the total count from Cell 2, had little trouble
passing through the sand filter and represented 56
percent of the total count from Filter A effluent.
Oscillatoria, the filamentous alga, and a notorious
Table 6. Summary of operating data, Blue Springs lagoon system, Cell 2 and Cell 3 sand filters, average values,
April 22 to May 24, 1974.
Sampling
Station
Prep. Sand
Cell 2, Fill. A
Prep. Sand
Cell2,Filt.B
Prep. Sand
Cell3,Filt.C
Prep. Sand
Cell 3, Fill. D
Flow
mgd
a
b
c
d
Temp.
°C
PH
7.45
7.47
7.50
7.56
BOD,
mg/1
20.8
18.5
15.0
14.2
COD
mg/1
75
74
66
66
NFS
mg/1
13
12
11
11
TotP
mg/1
8.38
8.14
8.82
8.28
NH3-N
mg/1
9.41
8.14
9.57
9.01
NO2-N03-N
mg/1
0.09
0.04
0.05
0.04
TKN
mg/1
12.53
12.05
12.46
11.86
TotN
mg/1
12.62
12.09
12.51
11.90
Fecal
Coliform
Organ/
100 ml
670
680
220
210
a4/21-5/2 10mgad;5/2 -5/14 1.25 mgad; 5/15-5/24 1.25 mgad.
b4/21-5/4 5 mgad; 5/5 -5/14 2.5 mgad; 5/15-5/24 2.5 mgad.
c4/21-4/24 10 mgad; 4/24-4/29 10 mgad; 4/30-5/24 1.25 mgad.
d4/21-4/28 5 mgad; 4/29 - 5/12 5 mgad; 5/13-5/24 2.5 mgad.
Table 7. Blue Springs Lagoon Study, winter 1974.
Celll
Cell 2
CellS
Phytoplankton Count
(cells/ml)
2,464 2,464
Predominate Algae
(% of total)
Oscillatoria 59% Oscillatoria 47%
Chlamydomonas 28% Chlamydomonas 28%
Chlorophyll a
(micrograms/m3)
0.576 0.630
3,157
Oscillatpria 63%
Chlamydomonas 24%
0.790
Filter A
1,232
Chlamydomonas 56%
Oscillatoria 37%
0.683
Filter C
1,848
Chlamydomonas 46%
Oscillatoria 29%
0.523
-------
196 Walter and Bugbee
filter-clogging form, was passed through the filter, but
in broken filaments and in a much smaller quantity.
Similar results were observed in Cell 3 and Filter C
effluent, even though the phytoplankton cell counts
were reduced by as much as 50 percent. By sand
filtration, the chlorophyll a data did not reflect this
reduction because the concentrations were bordering
on the lower detection limit.
By April, warmer water temperatures and in-
creasing daylight hours promoted heavy phyto-
plankton growth. Phytoplankton cell counts ap-
Table 8. Blue Springs Lagoon Study, spring 1974.
preaching or exceeding 100,000 per milliliter were
common in all three lagoons through April and
continuing into the mid-part of May. The pre-
dominate algal form during this period was the
coccoid green Micractinium. By filtering the effluent
from Cell 2, a 95 percent reduction in phytoplankton
cells, and a 42 percent reduction in chlorophyll a
content was accomplished.
The filtration fragmented the
Micractinium which allowed some passage through
the filter of broken cells and dislocated setae. A small
Celll
Cell 2
Cell 3
Phytoplankton Count
(cell/ml)
68,684
Predominate Algae
(% of total)
Micractinium 97%
Oscillatoria 1%
Chlorophyll a
(micrograms/m3)
24.03
116,424
Micractinium 73%
Oscillatoria 21%
24.03
96,096
Micractinium 96%
Euglena 1%
16.02
Filter A
5,852
Micractinium
(fragments) 35%
Euglena 22%
13.35
Filter C
7,392
Euglena 42%
Micractinium
(fragments) 16%
5.07
Table 9. Blue Springs Lagoon Study, summer 1974.
Celll
Cell 2
Cell 3
Phytoplankton Count
(cell/ml)
225,302
Predominate Algae
(% of total)
Oscillatoria 93%
Chlamydomonas 2% Euglena 6%
Chlorophyll a
(micrograms/m )
2,242.80 883.77
142,758
Oscillatoria 78%
108,262
Oscillatoria 87%
Euglena 2%
333.75
Filter A
9,086
Oscillatoria 47%
Ankistrodesmus 25%
14.68
Filter C
11,858
Oscillatoria 61%
Euglena 16%
12.01
-------
Blue Springs Lagoon Study, Blue Springs, Michigan 197
flagellate, Euglena, also passed through the filter
without much difficulty.
Filtering the effluent from Cell 3 also achieved
similar reductions in phytoplankton and chlorophyll
a. The phytoplankton cell counts declined 77 percent
with a corresponding 32 percent decline in
chlorophyll a concentrations in Filter C effluent.
In mid-summer, all three lagoons supported a
dense blue-green algae population dominated by
Oscillatoria, Phytoplankton cell counts were well over
100,000 cells/ml and chlorophyll a ranged from
2,242 to 333 //g/m3. As of this writing, biological
monitoring has indicated the phytoplankton cell
counts exceeding 500,000 ml and remedial copper
sulfate treatment will begin the week of August 19.
Nevertheless, filtration of Cell 2 and 3 effluents
demonstrates the effectiveness of sand filtration and
the subsequent reduction of algae cells, and
chlorophyll a content.
Dye studies were conducted on June 3, 1974,
to measure flow-through time. All three cells were
dosed simultaneously with rhodamine WT dye solu-
tion. Break through on Cell 1, 16.8 hectares (41.5
acres), occurred in 5 hours 10 minutes. Cell 2 which
is 5.0 hectares (12.4 acres) had initial break-through
in 4 hours 45 minutes. The first break-through in Cell
3, 1.7 hectares (4.15 acres), occurred 45 minutes
after release.
Our Blue Springs lagoon study is about half
finished. The summer intensive data which are being
generated presently, must be compiled and the
copper sulfate dosing and fall intensive are yet to be
done. The progress to date, as summarized, does not
include consideration of ail the analytical data but
only those related to the major objectives. We are
hopeful that the total results will provide additional
insight into design and operation of three-cell sys-
tems.
Reference
Harris, D. J., and William J. Keffer. £974. Wastewater
sampling methodologies and flow measurement tech-
niques. EPA 907/9-74-005.
-------
COST-EFFECTIVENESS ANALYSIS FOR WATER POLLUTION CONTROL
R. Smith1
Over the past 10 years, the direction of the
federal program in water pollution control has shifted
from the purely scientific aspects of the problem to
the more practical considerations of design and
cost-effectiveness (EPA, 1971). One of the first
indications of this change in attitude appeared in EPA
regulations published in the Federal Register on July
2, 1970. Subparagraph 601.36 entitled Design reads
as follows:
No grant shall be made for any project unless
the Commissioner determines that the proposed
treatment works are designed so as to achieve
economy, efficiency, and effectiveness in the
prevention or abatement of pollution or en-
hancement of the quality of the watei into
which such treatment works will discharge and
meet such requirements as the Commissioner
may publish from time to time concerning
treatment works design so as to achieve
efficiency, economy, and effectiveness in waste
treatment.
The Federal Water Pollution Control Act Amend-
ments of 1972 (PL 92-500) further charged EPA with
a number of specific tasks relating to development
and publication of information and guidelines.
Two principal milestones were mentioned in
the law. The first is achievement of secondary
treatment effluent standards in all publicly owned
treatment works by July 1, 1977, and the second is
achievement of best practicable treatment in all
publicly owned treatment works by July 1,1983.
The definition of secondary treatment was
published in the Federal Register on August 17,
1973. Principal provisions of this definition were that
the mean value of effluent samples collected over 30
consecutive days must not exceed 30 mg/1 for 5-day
BOD, 30 mg/1 for suspended solids, 200/100 ml for
fecal coliform bacteria, and the pH of the effluent
must fall between 6.0 and 9.0.
Although the formal definition of best
practicable treatment has not, as yet, been published,
IR. Smith is with the National Environmental Research
Center, Office of Research and Development, U.S. Environ-
mental Protection Agency, Cincinnati, Ohio.
it is expected that the definition will not contain a
minimum effluent quality. The term "best practicable
treatment" seems to be closely related to the concept
of cost-effectiveness. The term best practicable treat-
ment is first mentioned in PL 92-500 in Section 201
(gX2XA) which provides that the grant application
must satisfactorily demonstrate to the Administrator
that:
...alternative waste management techniques
have been studied and evaluated and the works
proposed for grant assistance will provide for
the application of the best practicable waste
treatment technology over the life of the works
consistent with the purposes of this title.
The term "best practicable technology" is defined in
PL 92-500 with reference only to non-publicly owned
facilities but in Section 304 (b)OXB) the following
statement appears:
Factors relating to the assessment of best
practicable control technology ... shall include
consideration of the total cost of application of
technology in relation to the effluent reduction
benefits to be achieved from such application,
and shall also take into account the age of
equipment and facilities involved, the process
employed, the engineering aspects of the
application on various types of control
techniques, process changes, non-water quality
environmental impact (including energy re-
quirements), and such other factors as the
Administrator deems appropriate.
Thus, it appears that the term best practicable
treatment is used to represent the ideal situation
where all aspects of each pollution control problem
are properly weighted and taken into account to
arrive at the ideal solution which maximizes the
common good and minimizes the common cost. The
law (PL 92-500) specifically states that social costs
and other intangible factors are to be taken into
account when the best practicable solution is deter-
mined.
While the concept of best practicable treatment
is defined to include social and other intangible
factors, such as conservation of energy, the concept
of cost-effectiveness is more easily understood and
more easily used in the solution of any specific
pollution control problem. For example, Appendix A
of 40 CFR, part 35, EPA regulations was published in
199
-------
200 Smith
the Federal Register on September 10, 1973. (See
Cost Effectiveness Analysis.) These cost-effectiveness
guidelines require the non-monetary aspects of the
problem to be included in descriptive terms only.
Conceptually, cost-effectiveness analysis means
identifying and enumerating all feasible alternative
ways of achieving the required level of treatment,
estimating the total cost of each alternative, and
finally, with proper consideration of the non-
monetary factors, selecting the least cost alternative.
The most important point made in the cost-
effectiveness guidelines is that the cost of each
alternative must be the total cost expressed as a
present value or an equivalent continuous cash flow.
Since the federal government is authorized to pay up
to 75 percent of the total cost as a grant-in-aid and
the states often pay another 10 to 15 percent, the
share of capital cost paid by the municipality is often
as little as 10 percent. On the other hand, the munici-
palities usually pay the entire amount for operation
and maintenance.
Therefore, in making a cost-effectiveness
analysis, the tendency is often to include only the
monies paid by the municipality which would be the
entire amount for operation and maintenance plus a
small fraction of the capital cost. When this approach
is taken, the least cost alternative selected will always
be capital intensive. The primary purpose of the
cost-effectiveness guidelines is to insist that the total
cost to federal, state, and municipal sources be used
as the total cost. Other important provisions of the
cost-effectiveness guidelines are listed below:
1. Extent of effort used should reflect the
size and importance of the project.
2. Twenty-year planning period must be
used.
3. Inflation of wages and prices shall not be
considered in the analysis.
4. Discount rate recommended by Water
Resources Council must be used.
It is obvious that an unlimited amount of effort
can be expended in seeking the most cost-effective
solution to any pollution control problem. This is
recognized in the' cost-effectiveness guidelines by
staling that the extent of the effort expended in
making the analysis should reflect the size and
importance of the project. This can be expressed in
another way by stating that the cost of the cost-
effectiveness analysis should be included as part of
the project cost.
It is generally believed that design of waste-
water treatment facilities tends to be capital intensive
because of the relatively small share of the capital
expenditure contributed by the municipality. The
cost of clean water reports have consistently reported
statistical data intended to show that, on the average,
wastewater treatment plants in the U.S. are under-
loaded, reflecting overestimates for population and
industrial growth in the community. Recom-
mendations for making more precise estimates of
projected population growth are given by EPA
(1972).
Examples of the kinds of questions which EPA
documents consistently recommend for cost-
effectiveness consideration are given as follows. First,
the feasibility of consolidating treatment facilities by
means of gravity sewers or force mains in order to
realize the economies of scale. Rough cost estimates
for plants and interconnecting pipelines can often
settle this question, but in cases where a real potential
for cost savings exists, a more detailed and precise
cost study will be necessary.
Careful consideration of the expected growth
of the residential and industrial segments of the
community served and the corresponding increase in
load on the treatment facilities should be made. Here
the potential advantages of staged construction of
treatment works should be considered.
The impact on the treatment facilities of
infiltration and inflow (Grants for Construction of
Treatment Works, 1973; and EPA, 1974) must be
considered to determine whether correction of the
sewerage system is more or less costly than expansion
of the treatment facilities.
The feasibility of using treated wastewater for
industrial or agricultural purposes should be explored.
If a demand for the treated wastewater exists, a
charge imposed on the user can be used to offset the
cost of treatment.
An important consideration is selection of the
treatment process train which will accomplish the
treatment target at a minimum cost. Treatment by
land application2 must be included in the cost-
effectiveness analysis. Process reliability3 in terms of
the variability of the effluent stream quality, protec-
2See Wastewater Treatment and Reuse by Land
Application, Vols. I and II, 1973; Survey of Facilities Using
Land Application of Wastewater. 1973; and Recycling
Municipal Sludges and Effluents on Land, 1973.
3See Design Criterion for Mechanical, Electrical, and
Fluid Systems and Component Reliability, 1973.
-------
Cost-Effectiveness Analysis for Water Pollution Control 201
tion against electrical power failure, protection
against flooding, and provision for taking equipment
and structures out of service for periodic cleaning and
maintenance should be considered. This kind of
analysis cannot be made in any precise way because
of the uncertain relationship between process design
parameters and the effluent quality achieved. For
example, the average effluent quality to be expected
from an activated sludge plant treating municipal
wastewater can be estimated when the character of
the raw wastewater stream and the design parameters
are known, but the precision of the estimate is
limited. Pilot plant results are more reliable but still
the precision may not be fully adequate for cost-
effectiveness analysis.
Engineering judgment must play a part in
selecting the set of processes needed to achieve any
treatment goal. For example, if the effluent standard
is 10 mg/1 BOD and 15 mg/1 suspended solids this is
achievable with the activated sludge process but
careful consideration of factors such as operating
sludge retention time (SRT), hydraulic detention
time, water temperature, final settler overflow rate,
etc., must be provided.
If the effluent standards require that the
ammonia be converted to nitrate, a similar problem
exists. The engineer must carefully consider SRT and
water temperature to determine if nitrification can be
reliably achieved in the activated sludge process or
whether a separate nitrification process is needed.
If denitrification is required by the effluent
standards, a decision between dispersed floe
denitrification, columnar denitrification, or the new
cycling nitrification-denitrification process-must be
made. The ammonia removal can also be achieved by
ion exchange or by breakpoint chlorination.
If phosphorus is to be removed, the required
level of phosphorus in the effluent stream is a factor
to be considered. Next, the designer must choose
between processes such as alum or iron addition with
the increased amounts of inorganic sludge produced
or the Pho-Strip process which has been tried
successfully at Seneca Falls, New York. Filtration is
sometimes required for removal of phosphorus to
very low levels or to remove additional suspended
solids and BOD.
Lime clarification of raw wastewater can be
used to remove phosphorus and to remove sufficient
BOD to assure good nitrification in the following
activated sludge process.
If a high degree of removal of organics is
required, granular carbon adsorption may be needed.
A package of cost and performance estimates, sup-
plied for use with the 1975 Needs Survey, is given in
Appendix A to show how the capital cost can vary
with the level of treatment required.
The impact of improved methods of operation
and maintenance on the effluent quality should also
be given careful consideration. Some forms of in-
strumentation and automation are believed to have a
beneficial impact on the average quality of the
effluent stream as well as the variability of the quality
measures. Certain kinds of automatic control, such as
dissolved oxygen control in the aeration basin, are
known to result in reduced operating costs. The
degree of automatic control should be selected to
achieve the effluent standards consistently at a
minimal cost.
Finally, storm water treatment facilities should
be integrated with dry weather treatment facilities so
that the maximum use is made of both types of
facilities in order to minimize the pollutional load on
the receiving stream.
The cost-effectiveness guidelines specify that no
allowance should be made for inflation in wages,
power cost, or capital cost. The reason for this is that,
ideally, the analysis should be made on the basis of
real value rather than dollar value. Dollars are used
only as a measure of real value and, therefore, when
the cost of any structure, equipment item, or service
is used, it must be referenced to a specific point in
time. This is done by means of various kinds of
indices such as the EPA sewer and treatment indices,
the average hourly wages of water, steam, and
sanitary system workers, wholesale price index for
industrial commodities, etc. For example, a plot of
the EPA indices for construction of sewers and
treatment plants is shown in Figure 1. The current
rate of increase for these indices is about 40 percent
per year.
The justification for omitting inflation, then, is
that it is assumed that the cost of all components of
the facility are being inflated at the same rate. If the
inflation rate for construction is known to be
significantly different than the inflation rate for, say,
electrical power, there is some justification for
considering inflation. Another reason for not con-
sidering inflation in cost-effectiveness analysis is the
uncertainty associated with estimating the rate of
inflation in future years.
Perhaps the most important concept in making
a cost-effectiveness analysis is the time value of
money. By this, we mean that one dollar today is
worth more than the promise to pay one dollar, say,
one year from now. For example, one dollar today
will be worth $1.05 in one year if the prevailing rate
of interest is 5 percent. It is also important in
-------
240
220
200
180
160
140
120
100
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Figure 1. Sewage treatment plant construction cost index and sewer construction cost index, 1957= 100.
rsrr
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-------
Cost-Effectiveness Analysis for Water Pollution Control 203
considering the cost of a service facility such as a
treatment plant or a sewerage system to consider cost
as distributed over an endless time continuum. For
truly continuous costs such as the cost of wages or
chemicals this presents no problem. For other items
such as equipment or structures which have a finite
useful life, provision must be made for replacement at
the end of the useful life period. This can be done by
accumulating money in a fund (sinking fund) or by
borrowing the money to purchase the needed replace-
ment item. The discarded equipment or structure
may have some salvage value but this is not significant
in most cases.
Thus, for cost estimation purposes, the costs
incurred must be visualized as being distributed over
the continuous and endless time continuum. The
costs can be expressed as a continuous cash flow or as
lump sums occurring at equal intervals. Since the
expenditures occur in a recurring pattern, it is
convenient to look at the costs over a finite interval
called the planning period. The cost-effectiveness
guidelines recommend the use of a 20-year planning
period.
Compounding of interest is most commonly
done on a yearly basis, but for illustrative purposes
continuous compounding is more convenient and will
be used here. The difference between continuous
compounding and yearly compounding is usually
small. The Water Resources Council's (1973) rate was
6 7/8 percent for fiscal year 1974 and the new
recommended rate for fiscal year 1975 will be 5 7/8
percent.
When one or more equally acceptable alter-
natives are being studied for the purpose of selecting
the least cost alternative, the stream of costs which
occur over the planning period must be converted to
an equivalent basis in order that the cost comparison
can be made.
For example, costs for all alternatives can be
converted to a present value, a future worth, or to a
continuous cash flow. By present worth, we mean an
equivalent lump sum expenditure which occurs at the
beginning of the planning period. If we designate time
from the beginning of the planning period as (t) and
the length of the planning period as (T), then the
present value is a lump sum payment made at t = 0.
Similarly, future worth is defined as a lump sum
expenditure made at t = T. By continuous cash flow,
we mean a continuous stream of expenditure at a
fixed rate with respect to time (R) expressed as
dollars per year.
By means of simple relationships, any stream of
expenditures can be converted to one of these three
equivalent expressions. When the cost of all alter-
natives are expressed on an equivalent basis, the least
cost alternative can be selected.
The actual expenditures which occur in connec-
tion with a particular alternative can be lump sums or
continuous expenditures but the rate of the continu-
ous expenditure need not be constant. If we designate
a lump sum expenditure which occurs at a time (t)
from the beginning of the planning period as S(t), the
relationships used to convert S(t) to a present value,
S(0), or to a future worth, S(T), are given below.
s(o) = s(tyrt (i)
S(T) = S(t)er(T-t) (2)
r = discount rate, fraction
When the stream of expenditures is continuous, the
expenditure at any time is expressed as Rdt but R can
be a function of time. Any continuous stream of
expenditures can be expressed as a present value by
the following expression:
S(0)
•f
Rert dt (3)
If R is a constant and the stream of expenditure
covers the entire planning period, the present worth
of the continuous cash flow is expressed as follows:
-rT\
S(0) = R(l-e'rl)/r
(4)
Similarly, the continuous cash flow (R) can be
expressed as a future worth as follows:
S(T) = R(e
rT
(5)
If the continuous cash flow covers only a portion of
the planning period, say from tj to t2, the present
value and future worth can be expressed as follows if
R is a constant:
S(0) = R(e'rtl - e'rt2Vr
S(T)= R(e"rt2-e"rtl)/r
(6)
(7)
If the continuous cash flow R is expressed as a linear
function such as (a + bt) and covers the entire
planning period, the present value of the linearly
increasing stream is expressed as follows:
S(0) = a(l - e'rT)/r + b(l - (1 + rTKrT)/r2 - (8)
If the continuous cash flow R increases exponentially
such as R = RQe8t, the present value of this
continuous stream can be expressed as follows when
the entire planning period is covered:
-------
204 Smith
S(0) = R(e(a-r)T -
(9)
Conversions between continuous cash flow,
present value, and future worth are shown dia-
gramatically in Figure 2. Six 20-year planning periods
are represented in Figure 2. In the first planning
period, a lump sum expenditure is shown at the
10-year point and the vertical lines on either end of
the planning period represent the present value and
the future worth of the lump sum expenditure made
at the 10 year point. In the second planning period
the future worth of a constant continuous cash flow
is represented. In the third planning period the
present value of a constant continuous cash flow is
represented. In the fourth period the present value of
a continuous cash flow between 10-15 years is shown.
The cash flow in the fifth period is linearly increasing
and present value is shown. The sixth period contains
an exponentially increasing cash flow with the
present value shown.
The normal method of financing municipal
wastewater treatment plants is to issue municipal
bonds and to pay the interest and principal on the
bonds over a 20-30 year period as a continuous cash
flow. The rate at which the money is paid can be
expressed as R dollars per year, or if continuous
compounding is assumed, the amount paid during the
time period dt is Rdt. Here, time is expressed as years
and dt is an increment of time. If the interest rate (r)
is known and the time period over which the
payments are to be made (T) is known, the required
rate of continuous payback (R) can be calculated.
If compounding is assumed on a yearly basis,
the value for R can be calculated from the following
simple formula:
(10)
R = debt service, dollars/yr
P = capital cost of plant, dollars
I = rate of interest, fraction per year
N = time period over which debt service
is paid, yrs
i
Figure 2. Diagramatic illustration of conversions between continuous cash flow, present value, and future
worth 20-year planning periods, 7 percent interest.
-------
Cost-Effectiveness Analysis for Water Pollution Control 205
If continuous compounding of interest is
assumed, R can be calculated if we first notice that R
is the sum of the interest on the unpaid balance (S)
over the time period dt plus the nega'tive derivative of
the unpaid balance with respect to time. This can be
seen from the diagram shown in Figure 3.
Figure 3 represents the debt service charge on a
capital cost of $1,000 amortized over 20 years at an
interest rate of. 7 percent. The area under the curve
represents the interest charges and the area above the
curve represents the payments on the principal. The
area above the curve between the ordinate represent-
ing zero time and any other ordinate representing a
time (t) equals the initial plant cost minus the unpaid
balance (S). Thus, any ordinate is the sum of the
interest charges (rS) and the rate of change of (P-S) or
•dS/dt.
The height of the rectangle representing the
continuous cash flow can be expressed as follows:
R = rS-dS/dt (11)
If we let the length of the rectangle representing the
planning period be T years, Equation 11 can be
integrated to find the following expression for R:
The amortization factor, defined as the fraction of
the plant cost (?) paid per year, is calculated from
Equation 12 as 0.09291. If the interest is com-
pounded yearly, the amortization factor is calculated
from Equation 10 as 0.09439. The difference between
these two factors is about 1.5 percent. Notice that
Equation 12 is equivalent to Equation 4.
In the example on continuous compounding,
the height of the rectangle is the product of the
amortization factor and the plant cost taken as
$1,000 or $92.91. Initially, the interest charges are
$1,000 x 0.07 or $70 and the amount for repayment
of the principal is $ 12.91. By integrating Equation 11
between any time (t) and T (20 years), the following
expression for the unpaid balance is found:
S=
.(13)
Therefore, the equation of the curve in Figure 3 is
just rS. Also, by differentiating Equation 13 with
respect to time, we find
dS/dt =
(14)
R = Pr/(l
•02)
Thus, it can be seen that Equation 13 can be
multiplied by (r) and added to the negative of
Equation 14 to equal (R).
Plant Cost - Unpaid Balance (P-S)
14 15 16 17 18 19
O 1
Figure 3. Distribution of continuous cash flow associated with debt service on $1000 expended at zero time
amortized at 7 percent interest over 20 years.
-------
206 Smith
If Equation 13 is multiplied by r and integrated
between zero and T, the total amount paid in interest
can be found.
-rT\
Interest Paid = RT-R(l-e )/r
.(15)
In the example cited, the amount of interest paid is
85.82 percent of the plant cost and the total amount
of dollars paid is 1.8582 times the plant cost.
A more general expression for the total interest
charges divided by the plant cost is given below:
I/p =
.(16)
An example of the way municipal bonds are
issued to provide for a payback as a continuous cash
flow is shown by the notice of sale of municipal
bonds for mental hygiene and retardation facilities.
The notice of sale is shown in Figure 4. The expected
rate of interest is approximately 6 percent com-
pounded semi-annually.
If Equation 12 is used to estimate the continu-
ous cash flow (R) required to pay back the
$45,000,000 with interest at 6 percent, the amount
which must be repaid each year is $3,475,486. The
division of this amount between interest charges and
principal is shown in Figure 5, assuming continuous
compounding. The estimated amounts for repayment
of principal from Figure 4 are shown plotted by the
circled points in Figure 5.
It can be seen that the continuous com-
pounding relationship matches the estimates reason-
ably well. In financing the 45 million dollar facility, a
total of 86.9 million dollars will be spent, 45 million
for payback of the principal and 42 million in interest
charges.
For the sake of clarity, consider the following
simple example. An activated sludge plant with a
design capacity of 4 mgd is being designed and the
designer plans to use mechanical aerators with vari-
able effluent weirs to allow the blade submergence to
vary as the load on the plant increases. The popula-
tion of the community served is expected to increase
by 1.5 percent per year over the 20-year planning
period. Thus, the initial flow expected at the plant is
2.96 mgd and this will increase to 4 mgd at the end of
the 20 year period.
The amount of oxygen required is estimated at
one pound of oxygen per pound of 5-day BOD
removed. The expected BOD removal in the activated
sludge process is 120 mg/1. Thus, if the field aeration
efficiency is 2.5 Ib 02/hp-hr, the initial rate of
electrical power consumption will be 49.37 hp or
36.8 kw. The power consumption at the design
capacity (4 mgd) can be estimated as 66.6 hp or 49.7
kw.
The plant designer is faced with choosing
between two brands of mechanical aerators. Brand A
has an initial cost of $15,000 and an average aeration
efficiency of 2.5 Ib 02/hp-hr while Brand B has an
initial cost of $20,000 and an average aeration
efficiency of 2.7 Ib 02/hp-hr. In order to satisfy the
oxygen demand at the end of the planning period,
both platform mounted aerators must be rated at 75
hp.
For simplicity, it will be assumed that the
aeration efficiency is independent of blade sub-
mergence. If we take the cost of electrical power as
1.5 cents/kw-hr, the annual cost for electrical power
to drive the mechanical aerators can be expressed as
follows:
O.OlStj
$/yr = $4,836 eu'ulDtfor Brand A
.(17)
$/yr = $4,477 e°'015t for Brand B (18)
To convert these two streams of expenditures
to a present value, we need only substitute them into
Equation 3 for R. Therefore, the present value of the
stream of expenditures represented by Equation 17
can be found by the use of Equation 9 in which the
value for (r) is the discount rate (taken as 7 percent)
minus the rate of growth (1.5 percent) or 5.5 percent.
The value for (R) is $4,835.52 for Brand A and
$4,477.33 for Brand B. When this is done, the present
value of electrical power for Brand A aerator is
computed as $58,659. For Brand B, the cor-
responding value is $54,304. Since the initial cost is
already in the form of a present value, these can be
added to give a total present value for Brand A of
$73,659. The corresponding value for Brand B is
$74,304. Therefore, over a 20-year period the net
savings in selecting Brand A is estimated as $645.
When the discount rate for municipal bonds is 7
percent and the growth rate for the community is 1.5
percent per year, the trade-off in aeration efficiency
with initial cost can be seen to be about $2,178 for
each 0.1 Ib O2/hp-hr increment in aeration efficiency.
Other factors, such as the difference in maintenance
and repair cost, can be worked into the analysis.
If the life of any process component exceeds
the planning period, the capital expenditure is con-
verted to a continuous cash flow and that part of the
continuous cash flow which covers the planning
period is then converted to a present value. In making
cost analysis, the preferred method is to convert all
expenditures to a continuous cash flow and then sum
the continuous cash flows for all items to find the
total cost expressed as a continuous cash flow. This
cost is then often converted to a total treatment cost
-------
Cost-Effectiveness Analysis for Water Pollution Control 207
Notice of Sale of Bonds
$45,000,000
STATE OF OHIO
MENTAL HEALTH FACILITIES BONDS, SERIES 1974A
NOTICE IS HEREBY GIVEN that sealed bids will be received
at the office of the Treasurer of State of Ohio in the Capitol
Building, Columbus, Ohio, until 11:OO o'clock a.m., Eastern
Daylight Saving Time, on
Tuesday, July 16, 1974
at which time and place said bids will be publicly opened and
read, for the purchase of all of the $45,000,000 State of Ohio
Mental Health Facilities Bonds, Series 1974A (the "Series 1974A
Bonds"), to be issued by the Ohio Public Facilities Commission
(the "Commission") to pay costs of capital facilities for mental
hygiene and retardation.
DATE, DENOMINATIONS, AND MATURITY: The Series 1974A Bonds
in coupon form and those originally issued in fully registered
form will be dated as of August 1, 1974. Coupon bonds will be
in the denomination of $5,000 and fully registered bonds will
be in the denomination of $5,000 or any multiple thereof, and
said bonds will be exchangeable as between coupon and registered
form. The Series 1974A Bonds will mature serially on June 1 in
each year as follows:
Year Principal Year Principal
$ 820,000 1988 $1,750,000
870,000 1989 1,855,000
920,000 1990 1,965,000
980,000 1991 2,035,000
1,035,000 1992 2,210,000
1,100,000 1993 2,340,000
1,165,000 1994 2,480,000
1,235,000 1995 2,630,000
1,310,000 1996 2,790,000
1,385,000 1997 2,955,000
-L^O-J 1,470,000 1998 3,135,000
1986 1,535,000 1999 3,310,000
1987 1,650,000
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
Figure 4. Notice of sale of municipal bonds appearing in the Cincinnati Enquirer June 24,1974 (in part).
-------
208 Smith
w
u
a
H
H o
o 2
Q
C
O
•H
0
10 12
14
16 18 20 22
24 25
Figure 5. Distribution between interest charges and payback of principal for financing a facility with a capital
cost of $45,000,000 at an interest rate of 6 percent over a 25-year period.
expressed as cents/1000 gallons of wastewater
treated.
The 1973 Survey of Needs conducted by EPA
asked each state to identify every plant planned for
construction by 1990 and to give estimates for the
cost and the effluent quality required. An analysis of
the information submitted by the states produced the
following results.
The survey showed that about 15,000 new
plants are planned and about 6,000 of these plan to
achieve an effluent quality in excess of the EPA
definition of secondary treatment. About 4,000 of
the 6,000 plants will make no provision for removal
of nitrogen and phosphorus and about 2,000 will
remove phosphorus, ammonia nitrogen or nitrogen. A
breakdown of the 1,868 plants which plan to remove
phosphorus, ammonia nitrogen or nitrogen is shown
below.
Number of Plants
Total Flow, mgd
Average Flow/
Plant, mgd
P
Re-
moval
1,868 962
13,923 7,166
7.45 7.44
NH3
Re-
moval
1,141
8,105
7.10
NO3
Re-
moval
182
2,081
11.43
Most of the plants which plan to remove
phosphorus estimate the concentration of phosphorus
in the effluent as 1 mg/1. Most of the plants which
plan to oxidize the ammonia nitrogen estimate the
concentration of ammonia nitrogen in the effluent as
1-2 mg/1.
The group of plants which planned no
phosphorus or nitrogen removal but planned to
exceed the EPA secondary standard of 30 mg/1 BOD
and 30 mg/1 SS contained 3,788 plants with effluent
BOD less than 30 mg/1 and 3,987 plants with
suspended solids in the effluent less than 30 mg/1. A
breakdown of plants according to BOD level and flow
is shown in Figure 6. Histograms, according to the
number of plants planning various levels of BOD and
SS, are shown in Figures 7 and 8. Most of the planned
effluent qualities fell in the 10-15 mg/1 class for BOD
and 15-20 mg/1 for the suspended solids.
The Federal Environmental Protection
Agency's grant-in-aid program for construction of
wastewater treatment represents a significant national
expenditure and careful planning and design to
minimize cost is easily justified.
For example, Deputy EPA Administrator John
R. Quarles reported in the July 18, 1974, issue of
Engineering News-Record that the total for con-
-------
Number of Plants
BODmg/1
26-30 303 11
21-25 553 39
16-20 1366 87
11-15 302 34
6-10 464 40
0-5 297 16
0-5 6-10
Figure 6. Distribution
54012102
18 10 8 8 3 3 0 1
35 19 9 6 2 10 1 0
92321420
12 8 5 3 2 1 3 1
58220101
11-15 16-20 21-25 26-30 31-35 3640 41-50 51-60
Flow, mgd
of plants planning to achieve a BOD standard of less than 30 mg/1 from
0 0
0 1
4 1
0 1
2 0
0 1
61-70 71-80
the EPA Needs
Total
1 3 1 0 0 334
0 3 2 1 1 651
0 0 10 2 1 1553
3 1 2 4 2 372
0 1 2 1 0 545
00 0 0 0 333
81-90 91-100 101-200201-300301-400 3788
Survey for 1973.
Cost-Effectiveness Analysis for Water Pollution Control 209
-------
210 Smith
160O
1500
1400
1300
1200
1100
1000
900
7OO
400
30O
200
10O
1L.L J__,.- _L
g_._ L..1
Q.
8 . 82r
17.18f?
I 1
,_
-_L_J_I_J L
•~i
\ i.
14.32%
.L:I L
8.79%
J.-J -5.
! i _1.
10
30
BOD, mg/1
I i
Figure 7. 1973 survey of needs municipal wastewater treatment facilities.
-------
Cost-Effectiveness Analysis for Water Pollution Control 211
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
:T~!- T7"t:
5 ,.
c *•
rt T" i
H
*---;-T
^ __L..ii_i
t~T
' ]
" 1 :
13.14?5
9.23%
38.48%
_;;_:ll^iL i)
___!
5
!
10
.13
20
30
, mg/1
Figure 8. 1973 survey of needs municipal wastewater treatment facilities.
-------
212 Smith
struction grant awards in fiscal year 1974 totaled
about 2.6 billion dollars. The actual cash outlays, that
is, the total of checks written in FY 1974 totaled
about 1.5 billion dollars. According to Mr. Quarles,
the cash outlays for other years have been as follows:
1974 Capital spending plans
Year
1968
1969
1970
1971
1972
1973
1974
Cash Outlay,
millions of dollars
120
130
180
480
410
680
1500
Since PL 92-500 authorizes the federal share of the
construction cost of interceptors, treatment plants,
and outfalls to be as much as 75 percent, the 1.5
billion dollar outlay represents as much as 2.0 billion
dollars in new construction.
Congress authorized, in Public Law 92-500, the
expenditure of five billion dollars in FY 1973, six
billion dollars in FY 1974, and seven billion dollars in
FY 1975. The Administration has released only four
billion of the seven billion authorized for FY 1975,
three billion of the six billion authorized for FY
1974, and two billion of the five billion authorized
for FY 1973.
The importance of the construction program
for water pollution control can be seen from a recent
estimate of new construction planned for 1974 by
U.S. business. The table shown in Figure 9, showing
spending plan by U.S. business in 1974, appeared in
the November 15, 1973, issue of Engineering News-
Record.
The Systems and Economic Analysis Section of
AWTRL at NERC Cincinnati has produced a number
of reports and computer decks which can be of value
in examining many of the questions associated with
cost-effectiveness analyses. For example, the
potential for consolidation of treatment plants by
means of interceptors and force mains and the
advantages of staged construction are treated by
Smith and Eilers (1971). A number of reports are
available on the cost and performance of various
processes and process trains. A cost estimating pro-
gram (Eilers and Smith, 1971) is available for
estimating the cost of complete plants when the size
of all structures and equipment are known. An
Executive Program (Eilers and Smith, 1970) is avail-
able which will solve for all process streams when
performance measures are known for each process.
This program is also capable of sizing all processes
when the performance measures are known and also
7974
P/annedf
1973-74
ALL MANUFACTURING..
lron& steel
Nonferrous metals
Elect, machinery
Machinery
Autos, trucks & parts
Aerospace
Other transp. equip.
(RR equipment, ships)
Fabric, metals & instrum..
Stone, clay & glass
Chemicals
Pulp& paper
Rubber
Petroleum
Food & Bev
Textiles
Misc. manufacturing
NONMANUFACTUniNG ,
Mining
Railroads
Airlines ,
Other transportation ,
Communications
Elect, utilities
Gas utilities ,
Commercial (1)
46.52
2.80
2.35
3.20
4.44
2.58
.59
.37
3.43
2.13
5.51
2.67
1.89
6.59
3.55
.88
3.54
67.33
3.69
2.21
1.78
1.66
13.90
18.56
3.23
22.30
+24
+ 52
+ 45
+ 13
+ 35
+ 20
+ 13
+ 10
+ 19
+ 43
+ 33
+ 45
+ 21
+ 21
+ 17
+ 17
- 5
+ 7
+ 30
+ 10
-24
+ 8
+ 5
+ 14
+ 5
+ 4
ALL BUSINESS 113.05
+14
fMcGraw-Hill Dept. of Economics. 'Based
on '73 estimates by U.S. Commerce
Dept. (1) Based on largo chain, mail order
and department stores, insurance lirms,
banks and other commercial businesses.
Figure 9. Estimated capital outlays for new plants
and equipment for U.S. business Engineer-
ing News Record November 15,1973.
solving for all recycle streams by means of iterative
computation. The cost of water renovation (Smith,
1971) for reuse is estimated and compared to the cost
of water production by conventional means. Various
reports are available on the potential for improved
performance and cost reduction by means of in-
strumentation and automation. Recent reports
examine the cost of alternative schemes for sludge
handling and disposal (Smith and Eilers, no date a)
alternative schemes for oxygen supply (Smith and
McMichael, no date), and potential control schemes
for the activated sludge process (Smith and Eilers, no
date b). A time dependent program for the aerated
lagoon was developed in connection with cost-
effectiveness studies of equalization basins (Smith et
al., 1973). Cost estimation programs have recently
been developed for dispsered floe nitrification and
denitrification, granular carbon adsorption, and
aerated and facultative lagoons. For example, the
program for lagoons is shown in Appendix B.
-------
Cost-Effectiveness Analysis for Water Pollution Control 113
References
Cost Effectiveness Analysis. 1973. EPA Regulations Title 40,
Chapter I, Subchapter D, Part 35> Appendix A, Federal
Register 38, No. 174, September 10.
Design Criteria for Mechanical, Electrical, and Fluid System
and Component Reliability. No date.
EPA-430-99-74-001.
Eilers, R. G., and R. Smith. 1970. Executive digital computer
program.for preliminary design of wastewater treat-
ment systems. NTIS, PB 222 765, November.
Eilers, R. G., and R. Smith. 1971. Wastewater treatment
plant cost estimating program. NTIS, Rept. No. PB 222
762, April.
Environmental Protection Agency. 1971. Guidelines, water
quality management planning. January.
Environmental Protection Agency. 1972. Cost effectiveness
in water quality programs, a discussion. October.
Environmental Protection Agency. 1974. Guidance for sewer
system evaluation. March.
Federal Water Pollution Control Act Amendments of 1972.
1972. Public Law 92-500, 92nd Congress, S.2770,
October 18.
Grants for Construction of Treatment Works. 1973. EPA
Regulations, Title 40, Chapter I, Subparagraph D, Part
35, Federal Register 38, No. 39, February 28.
Recycling Municipal Sludges and Effluents on Land. 1973.
Proc. of Conference held July 9-13, Champaign,
Illinois, Lib. of Congress Cat. No. 73-88570.
Secondary Treatment Information. 1973. EPA Regulations
Title 40, Chapter I, Subchapter D, Part 133, Federal
Register 38, No. 159, August 17.
Smith, R. 1971. Cost of wastewater renovation. NTIS, PB
213 805/6. November.
Smith, R., and R. G. Eilers. 1971. Economics of consolida-
ting sewage treatment plants by means of interceptor
sewers and force mains. NTIS, PB 213 803/8. April.
Smith, R-, and R. G. Eilers. No date. Alternative schemes
for sludge handling and disposal in wastewater treat-
ment plants. Available in preliminary form.
Smith, R., and R. G. Eilers. 1974. Control schemes for the
activated sludge process. Environmental Protection
Technology Series EPA-670/2-74-069. August.
Smith, R., R. G. Eilers, and E. D. Hall. 1973. Design and
simulation of equalization basins. NTIS 222 000.
February.
Smith, R., and W. F. McMichael. No date. Alternative
systems for supplying dissolved oxygen in wastewater
treatment. Available in preliminary form.
Survey of Facilities Using Land Application of Wastewater.
1973. EPA-430-9-73-006, July.
Wastewater Treatment and Reuse by Land Application.
1973. Vols. I & II, Environmental Research Series,
EPA-660/2-73-006b&a. August.
Water Resources Council. 1973. Establishment of principles
and standards for planning water and related land
resources. Federal Register 38, No. 174, September 10.
Appendix A
Table A-l. Identifying numbers for individual pro-
cesses or process trains.
Primary Sedimentation I 1
Primary Sedimentation II 2
Primary Sedimentation I & Iron 3
Primary Sedimentation II & Iron 4
High Rate Trickling Filter I 5
High Rate Trickling Filter II 6
Low Rate Trickling Filter I 7
Low Rate Trickling Filter II 8
Activated Sludge I 9
Activated Sludge II 10
Activated Sludge III 11
High Rate Trickling Filter I & Alum 12
High Rate Trickling Filter II & Alum . 13
Low Rate Trickling Filter I & Alum 14
Low Rate Trickling Filter II & Alum 15
Activated Sludge I & Alum 16
Activated Sludge II & Alum 17
Activated Sludge HI & Alum 18
Separate Nitrification 19
Separate Denitrification 20
Filtration & Alum 21
Note: Activated sludge and trickling filter groups include
primary sedimentation.
-------
214 Smith
PRIMARY
SETTLER
SLUDGE HANDLING SCHEME I,
2
ANAEROBIC DIGESTER
SLUDGE DRYING BEDS
SLUDGE HANDLING SCHEME II
PRIMARY
SETTLER
INCINERATOR
.ANAEROBIC
DIGESTER
Figure A-l. Sludge handling schemes I, II, and III.
-------
Cost-Effectiveness Analysis for Water Pollution Control 215
SLUDGE HANDLING SCHEME III
AIR FLOTATION
THICKENER
VACUUM FILTER
INCINERATOR
ID
-o
Figure A-l. Continued.
Table A-2. Estimated effluent stream quality (pollutant concentrations in mg/1) achievable with process trains
identified as PI, P2, P3, and P4. 9/10/11 means activated sludge treatment with sludge handling
schemes I, II, or III.
BOD
200
130
100
45
25
20
25
15
15
10
10
5
5
SS
200
100
50
60
30
20
30
15
15
20
20
5
5
COD
390
250
185
90
60
45
50
35
35
35
45
25
30
P
10
9
2
8
8
7
2
2
2
8
8
1
1
NH3-N
20
20
20
18
10
17
18
10
17
2
1
20
1
N03-N
0
0
0
0
10
0
0
10
0
18
1
0
1
PI
0
1/2
3/4
5/6
7/8
9/10/11
12/13
14/15
16/17/18
9/10/11
9/10/11
16/17/18
9/10/11
P2
0
0
0
0
0
0
0
0
0
19
19
21
19
P3
0
0
0
0
0
0
0
0
0
0
20
0
20
P4
0
0
0
0
0
0
0
0
0
0
0
0
21
Note: Expected Range = ± 15 percent for all estimates.
-------
216 Smith
' I : 0_ ...I _
Tmi!
Trended to June, 1973 , \
1
J i -
I I :
-U
11- . i
I !
L ^
i
, r 1
.
_a
i
i
1
j
i
.aJ—
J
J 4 b 6 7 H 9 H.
10
100
Design Capacity, millions of gallons per day
Figure A-2. Capital cost estimates for primary sedimentation plants with sludge handling schemes I (1) and II
(2) and for activated sludge plants with sludge handling schemes I (9), II (10), and III (11).
-------
Cost-Effectiveness Analysis for Water Pollution Control 217
-1-6%-
__ u.-.-j- ..I_— _j^,
I - I - 1 ! - 1 - P f : -- ; - !-!•-••
_^!_-i_l Trended to June, 1973
-
Design Capacity, millions of gallons per day
Figure A-3. Capital cost estimates for primary sedimentation plants equipped with facilities to add iron and
sludge handling schemes I (3) and II (4). Capital cost estimates for activated sludge plants equipped
with facilities to add alum and sludge handling schemes I (16), II (17), and III (18).
-------
218 Smith
H
i 1 !
Trended to June, 1973
! ,
j
"i1
: _ t
i - L;
• i
; ,
i .
LJ
I
1 I
i 1
i
I !
1 1
J_L
i
i.
i - ;
•••In:
'inn
r .
i
;• j"
1 1
•
;_.
i : •
L
j
-|
i-
3 -1 [i 6 7 U 9 1U
3 4 & b 7 u 9 i •
10
100
Design Capacity, millions of gallons per day
Figure A-4. Capital cost estimates for trickling filter plants with sludge handling schemes I (5 & 7) and II (6 & 8)
and for trickling filter plants with facilities for adding alum ahead of the final settler with sludge
handling schemes I (12 & 14) and II (13 & 15).
-------
Cost-Effectiveness Analysis for Water Pollution Control 219
1OCL
rnr FIT
i. -i
-*-1 f i ' I
_, , ,T,
Trended to June, 1973
If • ! ' : i ''•
Design Capacity, millions of gallons per day
Figure A-S. Capital cost estimates for separate nitrification (19), separate denitrification (20), and filtration
with supplementary alum addition (21).
-------
220 Smith
Appendix B
Table B-l. Input variables to waste stabilization pond cost estimating study.
QD Average daily volume flow used for design of the system, mgd
RI Amortization interest rate, fraction
YRS Amortization period, years
DA Cost of land, dollars/acre
DHR Hourly labor rate, dollars/hour
CCI Sewage treatment plant construction cost index, 1967 = 1.00
WPI Wholesale price index, 1967 = 1.00
BODIN 5-day BOD concentration of the pond influent stream, mg/1
PLOAD 5-day BOD loading on the system, Ib BOD/day/acre
HP Total installed capacity of the mechanical aerators, horsepower/million gallons
DCL2 Dose of chlorine, mg/1
TCL2 Chlorine contact time, minutes
FSLAB Fraction of pond protected by concrete embankment
HEAD Pumping head of raw wastewater pumps, feet
FORK Program control: 0 = non-aerated pond, 1 = aerated pond
TEMP Program control: 0 = non-aerated pond in a cold climate, 1 = non-aerated pond in a warm climate
SLAB Program control: 0 = no concrete embankment protection, 1 = concrete embankment protection
included
CL2 Program control: 0 = no chlorination contact basin or feed system, 1 = chlorination contact basin
and feed system included
DEEP Program control: 0=10 feet deep aerated pond, 1 = 15 feet deep aerated pond
SAER Program control: 0 = small impeller floating mechanical aerators, 1 = large impeller stationary
mechanical aerators
PUMP Program control: 0 = no raw wastewater pumping, 1 = raw wastewater pumping included
ECFO Excess capacity factor (raw wastewater pumping)
ECF1 Excess capacity factor (stabilization pond, non-aerated)
ECF2 Excess capacity factor (stabilization pond, aerated)
ECF3 Excess capacity factor (surface aerators)
ECF4 Excess capacity factor (concrete embankment)
ECF5 Excess capacity factor (chlorination contact basin)
ECF6 Excess capacity factor (chlorination feed system)
-------
Cost-Effectiveness Analysis for Water Pollution Control 221
10
-8
o
o
•rl
o
r-t
>rt ^
CL • JL
.01
treatment cost
100,
10.
I-1 1.
.1
.1
1.
10.
(fi
c
o
o
o
o
V)
•p
c
8
c
I
s
H
Design Capacity, million gallons per day
Figure B-l. Estimated cost trended to January 1974 for waste stabilization ponds in warm climates with the
design criteria of 50 Ibs BOD/day/acre.
-------
222 Smith
10.
0)
* i
-8
-------
Cost-Effectiveness Analysis for Water Pollution Control 223
10. CT
H
I
H
H
•p
to
8
•P
•H
1.
,01
H treatment cost
100.
10,
.1
1.
Design Capacity, million gallons per day
in
C
o
H
H
d
o
8
H
\
(0
•p
8
i
•p
Ki
OJ
)-(
H
.1
10.
Figure B-3. Estimated cost trended to January 1974 for aerated lagoons with the design criteria of 170 Ibs
BOD/day/acre.
-------
.1 MOD WASTE STABILIZATION POND XARH CLIMATE PUMPING JAN 1974
K>
-b.
COST ESTIMATE 05
FOR 3
HASTE STABILIZATION PONDS S
PROCESS COMPONENTS
RAW KASTEWATER PUMPING
STABILIZATION PONO-NONAERATEO-W
SUBTOTAL
ENGINEERING COST
LAND RECUIREO, 9.78 ACRES
LAND COST
SUBTOTAL
LEGAL, FISCAL, ADMINISTRATIVE
SUBTOTAL
INTEREST CURING CONSTRUCTION
GRA.NO TOTAL
00 RI YRS
0.100 0.060 25.000
BCD IN PLOAD HP
200.000 50.000 0.000
FORK TEMP SLAB
0.000 1.000 0.000
DESIGN CONSTRUCTION
PARAMETER COST, *
0.10 MGD 29602.
3.33 ACRES 45754.
75356.
14766.
14682.
104806.
3524.
108330.
1344.
109675.
OA OHR CC1
1500.000 4.340 1.881
OCL2 TCL2 FSLAB
0.000 0.000 0.000
CL2 DEEP SAER
0.000 0.000 0.000
CAPITAL DEBT COST 0+H COST TOTAL COST
COST, $ CTS/1000 CTS/1000 CTS/1000
43084. 9.233 12.262 21.496
66590. 14.271 4.720 18.992
109675. 23.505 16.903 40.488
HP I
1.405
HEAD
30.000
PUMP
1.000
EXCESS
CAPACITY
1.00
1.00
Figure B-4. Cost estimate for waste stabilization ponds, warm climate.
-------
.1 MGO
WASTE STABILIZATION POND
COLD CLIMATE
PUMPING
JAN 1974
COST ESTIMATE
FOR
WASTE STABILIZATION PONDS
PROCESS COMPONENTS
RAH HASTEWATER PUMPING
STABILIZATION- PONO-NONAERATEO-C
SUBTOTAL
ENGINEERING COST
LAND REQUIRED, 20.03 ACRES
LAND COST
SUBTOTAL
LEGAL, FISCAL, ADMINISTRATIVE
SUBTOTAL
INTEREST DURING CONSTRUCTION
GRAND TOTAL
QD RI YRS
0.100 0.060 25.000
BODIN PLOAO HP
200.000 17.000 0.000
FORK TEMP SLAB
0.000 0.000 0.000
DESIGN CONSTRUCTION
PARAMETER COST, $
0.10 MGD 29602.
9.80 ACRES 98469.
128072.
20669.
30049.
178791.
4964.
183756.
2876.
186632.
DA DHR CCI
1500.000 4.340 1.881
DCL2 TCL2 FSLAB
0.000 0.000 0.000
CL2 DEEP SAER
0.000 0.000 0.000
CAPITAL DEBT COST
COST, $ CTS/1000
43138. 9.245
143494. 30.753
186632. 39.999
WPI
1.405
HEAD
30. COO
PUMP
1.000
0+M COST TOTAL COST EXCESS
CTS/1000 CTS/1000 CAPACITY
12.262 21.508 1.00
4.644 35.397 I .00
16.906 56.905
Figure R-5. Cost estimate for waste stabilization ponds, cold dimate.
-------
I MOD
AERATED LAGOON
PUMPING
JANUARY 1974 DOLLARS
COST ESTIMATE
FOR
WASTE STABILIZATION PONDS
PROCESS COMPONENTS
RAW WASTEWATER PUMPING
STABILIZATION PCND-AERATEO 15FT
SURFACE AERATORS-STATIONARY
CONCRETE SLAB EMBANKMENT
CHLC3INAT1GN CONTACT BASIN
CHLORI:NATION FEED SYSTEM
SUBTOTAL
ENGINEERING COST
LAND REQUIRED, 4.84 ACRES
LAND COST
SUBTOTAL
LEGAL, FISCAL, ADMINISTRATIVE
SUBTOTAL
INTEREST CURING CONSTRUCTION
GRAND TOTAL
DESIGN
PARAMETER
0.10 MGD
0.98 AC
10.00 HP
00
0.100
80DIN
200.000
FORK
I.000
RI
0.060
PLOAO
170.000
TEMP
0.000
YRS DA
25.000 1500.000
HP
10.000
SLAB
1.000
OCL2
15.000
CL2
1.000
CONSTRUCTION
COST, S
50 29602.
CRES 41056.
P 33477.
CRES 7401.
U FT 4656.
B/OAY 15330.
DHR
4.340
TCL2
30.000
DEEP
1.000
131524.
21C29.
7265.
159819.
4623.
164442.
2462.
166904.
CCI
1.881
FSLAB
1.000
SAER
1.000
CAPITAL DEBT COST 0+M COST TOTAL COST
COST, $ CTS/1000 CTS/1000 CTS/1000
37566. 8.051 12.262 20.314
52100. 11.166 0.000 11.166
42483. 9.104 18.627 27.732
9392. 2.012 0.000 2.012
5908. 1.266 0.000 1.266
19454. 4.169 6.419 10.589
166904. 35.770 37.310 73.081
HPI
1.405
HEAD
30.000
PUMP
1.000
EXCESS
CAPACITY
1.00
1.00
1.00
1.00
1.00
1.00
Figure B-6. Cost estimate for waste stabilization ponds, pumping.
-------
NOTE:
RESEARCH ON COLD CLIMATE WASTEWATER LAGOONS
H. J. Coutts1
The waste treatment research effort of the
Arctic Environmental Research Laboratory has been
concentrated on aerated lagoons and extended aera-
tion processes.
Stabilization (facultative) ponds have not been
extensively used in Alaska, therefore most of the
performance data is from Northern Canadian lagoons.
Data on facultative lagoons north of 52° north
latitude indicated winter BOD removals of 30 to 73
percent at detentions from 70 to 200 days.2 Summer
BOD removals were generally above 70 percent.
The Arctic Environmental Research Laboratory
research and monitoring field effort has been con-
centrated on an experimental lagoon at Eielson Air
Force Base, Alaska; a lagoon receiving total sewage
(~ 1/3 mgd) from Ft. Greely, Alaska; a small lagoon
serving 14 residential houses at Northway, Alaska;
and a lagoon serving Eagle River, Alaska (~ 1/7 mgd).
All the above lagoons were aerated with submerged
devices. The aeration rates were high enough to
prevent thermal stratification but not sufficient
enough to prevent settleable solids from precipitating.
The detentions varied from 12 to 30 days.
Experience with the Eielson Air Force Base
aerated lagoon has shown that first year data is not a
reliable indicator (at least for cold regions) of long
term performance. Due to algal blooms the first
winter's (startup) performance was better than the
following summer. After the first year the summer
performance was consistently better (than winter).
Apparently it takes a while for the bottom sludge tc
accumulate and digest adding to effluent BOD.
Performance data for many northern aerated
lagoons are summarized and plotted in Figure 1.
IH. J. Coutts is Chemical Engineer, Arctic Environ-
mental Research Laboratory, Environmental Protection
Agency, College, Alaska.
2"Biok>gical Waste Treatment in the Far North,"
Federal Water Quality Administration, Northwest Region,
Alaska, Water Laboratory 1610, June 1970. Now Arctic
Environmental Research Laboratory, Environmental Protec-
tion Agency, College, Alaska 99701.
yj
70
50
m
Sm
J
\
T€R _
c
/
/
/
^
/
, -—
^
^ i
— —
INTER
•
1
10 20 30
DETENTION TIME - DAYS
Figure 1. Average performance data on nine cold
region aerated lagoon systems, Arctic
Environmental Research Laboratory,
August 1974.
It should be recognized that there is consider-
able range in the data and that many winter and
summer points overlap. Figure 1 is preliminary and
should not be used for design.
The data are from the four above-mentioned
Alaska lagoons, three Canadian research lagoons, one
North Dakota, and three Minnesota lagoons. A
comprehensive report on Cold Climate Aerated
Lagoons is to be published by the Arctic Environ-
mental Research Laboratory this winter.
Recommendations by the Arctic Environmental
Research Laboratory on aeration devices are applicable
to all aerated lagoons, independent of temperature.
The recommendation is to avoid restricted orifices
when submerged aerators are used. An example of
restricted orifice devices are slitted tubing or porous
stones (ceramic plugs), which tend to clog very
readily. The AERL Working Paper No. 17 3 quantifies
the economical advantages of using coarse bubble
(open) aerators versus fine bubble (restricted
aerators).
3"Coarse Bubble Diffusers for Aerated Lagoons in Cold
Climates," by Conrad D. Christiansen, Working Paper No. 17,
U.S. Environmental Protection Agency, National Environ-
mental Research Center, Arctic Environmental Research
Laboratory, College, Alaska 99701.
227
-------
NOTE:
POLISHING GRAVEL AND ACTIVATED CARBON FILTER
ON AERATED LAGOON EFFLUENTS
G. Hartmann
Region VIII has a construction grant project for
the Boxelder Sanitation District in Fort Collins,
Colorado, under construction that entails the use of a
polishing lagoon with a gravel and activated carbon
filter at the end of an aerated lagoon system. The last
week of August was the first time that the filter was
put on line and to date no data are available on its
performance.
The project consists of expanding and up-
grading a 4-acre facultative pond with the addition of
two, 2-acre aerated lagoons that can be operated in
series or parallel, followed by the existing facultative
lagoon that will now be used as the polishing cell in
the lagoon system. Built into the discharge end of the
dike of the existing lagoon is a gravel and activated
carbon filter. The project was conceived and designed
to meet the State of Colorado effluent standards for
1978 of 20 mg/1 for BOD5, SS, color and turbidity.
The State of Colorado was instrumental in
getting this project underway and hopes to gain data
from it which will enable communities in Colorado to
be able to upgrade their lagoons in an effective and
economical manner. The total construction cost of
the filter, including the air supply, was $56,000.
Seventy-five percent of the project costs was paid for
with federal grant funds.
The filter itself consists of three zones of gravel
followed by a zone of activated carbon. The gravel
and activated carbon are placed in such a manner that
the flow through each zone is horizontal, with each
zone contiguous to the next.
The pond effluent first passes through a 30-foot
wide zone of 1^-inch gravel, then through a 13.5-foot
wide zone of 3/4-inch gravel, then through a 4.5-foot
G. Hartmann is with the Environmental Protection
Agency, Region 8, Denver, Colorado.
zone of pea gravel, before passing through approxi-
mately 14 feet of coarse activated carbon. Effluent
may be drawn off from the filter after going through
the first two gravel zones or after passing through the
entire gravel and activated carbon filter. The deten-
tion time for passage of the pond effluent through
the filter is quite long, being on the order of days.
The filter has been constructed with 8-inch
perforated PVC air discharge pipes in the bottom of
the filter. The spacing of the air discharge pipes varies
with the filter medium size, with a closer pipe spacing
for the smaller media. Two 15 HP blowers and
motors have been included to provide for delivery of
air through the filter when required.
The Boxelder Sanitation District and the con-
sultant plan to sample the filter influent and effluent
for BOD5, SS, NH3, NO3, turbidity, and color.
However at this time the owners and consultant have
not yet decided on the extent of the sampling
program. The filter has sampling tubes installed in the
filter so that samples may be drawn from several
different places in the filter to evaluate the perfor-
mance of the filter as flow passes through.
The district and consultant plan to operate the
filter in several different modes. With the placement
of air diffusers in the filter, it is hoped that it will be
possible to operate the filter in an aerobic or
anaerobic mode. The water level in the final lagoon
can be regulated so that the filter can be kept flooded
or left dry if desired. Shortly the district and
consultant will be developing a series of operational
modes and developing a monitoring program for each
specific operational mode that is used.
The EPA Region VIII Office intends to keep as
fully informed as possible on the monitoring of the
filter and will attempt to make these monitoring
results available as they are obtained.
Owner of the Project—Boxelder Sanitation
District, Fort Collins, Colorado
Consultant-M & I Engineers, Fort Collins,
Colorado
229
-------
MEMBERS OF THE SYMPOSIUM
NAME
Donald A. Anderson
J. David Ariail
Charles K. Ashbaker
Richard Bowman
Robert L. Bunch
Stephen L. Bugbee
Robert J. Burm
Robert B. Cameron
Charles H. Campbell
Jack Coutts
Roger Dean
Lloyd Denley
Evan Dildine
Les Dixon
William R. Duffer
Jerry N. Dunn
Larry E. Eason
Don Ehreth
Fred Evans
Ted Forester
Robert L. Fox
John Gall
William L. Garland
Robert A. Gearheart
Bill J. Gilbert
Terry Hagin
Hugh G. Hannah
Lynn Harrington
Joe L. Haney
REGION
EPA, Region 9, San Francisco
EPA, Region 4, Atlanta
Oregon Dept. of Environmental
Quality
State of Colorado-Denver
EPA, NERC, Cincinnati, Ohio
EPA/SUAN Region 7, Kansas
City, Kansas
EPA Region 8, Permits
HQS Alaskan Air Command/
DEMV
EPA, Region 9, San Francisco
Arctic Environmental Res.
Lab., U.S. EPA Fairbanks, Alk.
EPA, Region 8, Denver, Colo.
Mayor, California, Mo.
EPA Region 8, Denver
USU, Logan, Utah
EPA, NERC, Corvallis ADA,
Oklahoma
Corps of Engrs., Alaska Dist.
Anchorage, Alk.
Riddle Engineering Inc.
EPA/ORD Process Develop-
ment, Washington, D.C.
Iowa Dept. of Environmental
Quality
Missouri Clean Water
Commission
EPA Region 8, Denver, Colo.
EPA, Region 1, Boston
DEQ, Cheyenne, Wyo.
USU, Logan, Utah
Supt. Utilities, California, Mo.
EPA, Region 8, Denver, Colo.
Ark. Dept. of Pollution Con.
and Ecology, Little Rock,
Arkansas
EPA/Region 7
Region 6, EPA, Dallas, Texas
NAME
George Hartmann
Carl F. Heskett
Ronald F. Lewis
Christine Macko
Stanley Martinson
Robert W. Mason
Ross E. McKinney
E. Joe Middlebrooks
Merritt A. Mitchell
Paul J. Molinari
Willis H. Morris
Steve Moehlmann
Warren Myers
James D. Nelson
Walter J. O'Brien
James Ouchi
Steven Pardieck
Gerry Pidge
Donald M. Pierce
Jay Pitkin
Donald B. Porcella
Roy E. Prior
Jim Reynolds
John T. Riding
William A. Rosenkranz
David Sanders
Paul C. Schwieger
Ray G. Seidelman, Jr.
Bell C. Self
REGION
EPA, Region 8, O&W
EPA, Region 8, Denver, Colo.
EPA, NERC, Cincinnati, Ohio
USU, Logan, Utah
Calif. Water Resource Con.
Bd., Water Quality Division
EPA, Region 2, New York,
N.Y.
Univ. of Kansas
USU, Logan, Utah
EPA Arctic Lab., Fairbanks,
Alk.
EPA, Region 2, New York,
N.Y.
HQS Alaskan Air Command/
DEMV
Utah State Div. of Health
Montana Dept. of Health
S.D. Dept. of Environ. Prot.
Pierre, S.D.
University of Kansas,
Lawrence
EPA, Region 5, Chicago
EPA, Region 9, San Francisco
USU, Logan, Utah
Special Consultant EPA
Utah State Div. of Health
USU, Logan, Utah
DEQ Cheyenne, Wyo.
USU, Logan, Utah
Va. State Water Control Bd.
Munic. Pollution Con. Div.,
ORD, EPA, Washington
Missouri Clean Water
Commission
DEQ Cheyenne, Wyo.
Dept. of Environ. Con.,
Lincoln, Nebraska
USU, Logan, Utah
231
-------
232 Members
NAME
Norm Sievertson
John C. Taylor
Dick Thomas
Warren R. Uhte
LaRue S. Van Zile
REGION
EPA, Region 10, Seattle,
Washington
EPA, Region 5, Chicago
Construction Grants
ADA Lab. EPA, ADA,
Oklahoma
Brown and Caldwell, Walnut
Creek, Calif.
Va. State Water Control Bd.
NAME
REGION
William A. Whittington EPA Office Water Program
Operations
Jack Witherow IWB-EPA, Corvallis, Oregon
George M. Woolwine EPA, Region 3, Philadelphia
David Word
Don Zollman
Georgia Water Quality
Control, Atlanta
Montana Dept. of Health-
Helena
-------
APPENDIX
MONITORING REQUIREMENTS FOR PONDS
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Dr. E. J. Middlebrooks
Dean, School of Engineering
Utah State University
Logan, Utah
Dear Dr. Middlebrooks:
During the recent workshop on Wastewater Treatment Ponds which
your University hosted, a question was raised regarding the monitoring
requirements for ponds.
The attached memorandum was obtained from our Permit Policy
Branch. You will see that their guidance is that "permits should
require sampling of major parameters at least once per month for
small facilities' . It also recognizes that some facilities will need
time to achieve minimum monitoring requirements.
Also attached is a table of monitoring requirements extracted from
"Permit Program Guidance for Self-monitoring and Reporting Re-
quirements", dated October 1, 1973.
Sincerely yours,
tt
Sanitary Engineering
Municipal Technology Branch(WH-447)
Attachments
233
-------
234 Appendix
P.G. Permit No. 14
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
SUBJECT: Self-monitoring Date: February 15,1974
FROM: Michael Cook, Acting Branch Chief
Permit Policy Branch
TO: Regional Permit Branch Chiefs
and
Regional Municipal Permit Coordinators
THRU: Kenneth L. Johnson, Director
Municipal Permits & Operations Division
Concern and some confusion was expressed at our meetings January 14 and 17 with the Regions in Atlanta
and Seattle about guidance from the headquarters on monitoring frequency. This memo is intended to summarize
briefly our guidance on this subject, and supplement it in the few areas where it needs clarification. The self-
monitoring form to be used is also discussed.
The document, Permit Program Guidance for Self-monitoring and Reporting Requirements, dated October
1, 1973, states that permits should require sampling of major parameters at least once per month for small
facilities, and more often for larger ones. Where facilities have industrial flows, required sampling frequency
is to be based on industrial monitoring guidance in the same document. The frequencies listed in the document
are considered to be minimums. Regions should establish more rigid requirements where appropriate.
Some facilities will need time to achieve minimum requirements. Guidance for these cases is provided in
Jack Rhett's memo of August 20, 1973 to the Regional Municipal Permit Coordinators, entitled "Use of Draft
Municipal Permits"; and in his memo of November 15,1973 to the Regional Administrator of Region VII,
entitled "Monitoring Periodicity for Small Municipalities."
Permit Program Guidance for Self-monitoring and Reporting Requirements calls for a self-monitoring
report on a quarterly basis from all municipal facilities. The quarterly report is to consist of three monthly
summary reports completed on the EPA-designated reporting form, or a State reporting form approved by
EPA for this purpose.
We have decided after consultation with the Regional Offices to adapt EPA Form 3320-1 (10-72) for use
as the municipal self-monitoring reporting form. A draft of the modifications we propose to make in this form
will be distributed shortly for your comment.
-------
Table III
Municipal Wastewater Treatment Facilities
Minimum Sampling Frequency
Appendix 235
Effluent
Plant Size (mgd)
Up to 0.99
1 - 4.99
5 - 14.99
15 and greater
|
E
Once
Each
Wkday.2
Daily
Daily
Daily
^
^•i
<§
Q1
03
0
£
•o
o
VJ
•o
•S
c
u
Sf
a
ex,
/.^
^b,
V
H
c
o
1^
•^
^
T3
(S
h
£
^
o
13
.w /^^
'i s
^^ ?s
"8-
*^u
•^
^^
•S
^
C/3
3
«3
*
Once per month
Once per week
Once per weekday
Once per day
1. In smaller plants, we should accept
total colifoim rather than fecal coli-
form at this time.
2. Weekday = Monday - Friday.
3. Grab Sample.
-------
236 Appendix
UTAH STATE U N I V E R S I T Y • L O G A N . U TA H 84322
COLLEGEOF ENGINEERING
UMC 41
OFFICE OF THE DEAN
801-752-4100
ext. 7801 or 7802
October 23, 1974
James D. Nelson
South Dakota Department of
Environmental Protection
Pierre, South Dakota 57501
Dear Mr. Nelson:
We are attempting to finalize the proceedings for the symposium on upgrading waste water stabili-
zation lagoons, and only one written question has been received for inclusion in the appendices. We are
still debating as to whether to include a question and answer section because of the shortage of written
questions. However, I felt it only appropriate that your question be answered, and because it was
directed to me, I will attempt to answer the question in the following paragraphs.
Your question was: "A two-cell stabilization pond provides 120 day winter storage and the effluent
from the pond averages 50 mg/1 BOD5 and 70 mg/1 suspended solids. Would you recommend the addition
of a third cell or another method of treatment such as intermittent sand filtration to comply with the
secondary treatment standard?"
I doubt very seriously that the addition of a third cell to the present two-cell system will improve the
effluent quality significantly. I would recommend that the intermittent sand filter, rock filter, or some
other addition to the present system be considered and carefully evaluated. This is the only way that you
will obtain a consistent quality of effluent and meet the secondary standard.
I realize that the above answer is rather general, but to avoid being considered biased in my recom-
mendation I feel it only fair that you consider other techniques. The intermittent sand filter used in series
with the lagoon effluent passing first through a course sand with an effective size of approximately 0.7 mm,
to a finer sand (effective size ~ 0.4 mm) and eventually to a sand similar to the one that we have used in
our early evaluation (effective size of .17 millimeters) will provide an excellent effluent. Based upon the
preliminary data that we have collected the series process will perform an entire season before plugging if
the unit is loaded at a loading rate of 0.5 million gallons per acre per day. The optimum loading rate for
a series type operation remains to be determined; however, we feel sure that a value greater than 0.5 million
gallons per acre per day will be selected as the design value. I would recommend very strongly that a series
type system be employed. If you have additional questions or wish me to elaborate further on your above
question, please let me know.
Sincerely yours,
&f Joe Middlebrooks
Dean
EJM:js
-------
AUTHOR INDEX
Alley, F.C., 147, 175
American Public Health Association, 36, 45, 75, 87
American Society of Civil Engineers, 47, 68, 71, 87
Amin.J. V., 157, 174
Amramy, A., 137,172
Anderson, D. B., 157, 175
Anne, P., 156, 172
Ainon, D. I., 152,156, 172
Assenzo, J. R., 147, 172
Attoe.O.J., 177
Aulenbach, D. B., 185, 186
Avnimelech, Y., 137,166,172
AWWA, 87
Ayers, A. D., 175
B
Balassa.J., 154,177
Bancroft, P.M., 137, 172
Bardach, J.E., 188, 189
Barnette, R. M., 177
Barsom, G., 3, 4, 5, 14
Barth, E. F., 45
Batchelder, A. R., 175
Bauer, L. D., 138, 172
Baxter, S. S., 184,186
Bear, F. E., 176
Beath.O.A., 162,177
Beaton, J. D., 163, 172
Bendixen, T. W., 174,177
Berger, K. C., 177
Bernstein, L., 155, 163, 172,173
Berry, A. E., 31,45
Bingham, F. T., 155,159, 172
Bisbjerg, B., 162, 172
Bishop, W. B. S., 157, 172
Blair, G. Y., 178
Bott, R. F., 175
Borchardt, J. A., 31, 45, 55, 68
Bower, C. A., 178
Bowling.J. 0., Jr., 174
Bradfield, R., 173,178
Bradford, G. R., 175
Bredell, G. S.,173
Brennan, E. G., 175,176
Brewer, R. F., 156,172
Bronson, J. C, 176
Brown, A. L., 158, 159, 172
Brown, L C., 172
Brown, J.W., 153,177
Bugbee, S. L., 191
Calaway, W. T., 47, 51,58, 68,72, 87, 88
Campbell,!. D., 156,172
Cannell, G. H., 159,172
Carpenter, R. L,, 189
Carroll, W. R., 68, 87
Champlin, R. L, 5,14
Chang, C.W., 157.173
Chang, S. L., 137,173
Chapman, H. D., 153,172,173,176
Chichester, H. G., 189
Chipman, E. W., 174
Christiansen, C. D., 5,14
Clark, E., 137, 173
Clark, N. A., 137,173
Clark, R., 174
Cleary, E. J., 137,176
Clements, H. F., 158,173
Clesceri, N. L., 186
Cohn.M.M., 184,186
Colby, W. G., 178
Coleman, M. S., 189
Coleman, R., 163,173
Cooper, R. C., 176
Cooper, W. C., 154,173
Cope,J.T.,Jr., 162,173
Corbett, E. G., 155, 173
Cram.W. H., 178
Qites, R.W., 184, 185,186
D
Daines, R. H., 175,176
Davis, D. E., 176
Davison, V. E., 149,173
Day, A. D., 137, 171,173
Dean,R.J., 184,186
Deaner, D. G., 183, 184, 186
Deatrick, E. P., 157,173
Delaney, T. B., Jr., 185, 186
Dennis, J. M., 137,173
DeTurk,E. E., 137,173
Dinges, R., 188, 189
Dixon, N., 174
Dodd, J. C., 31, 46
Doner, H. E., 173
Dornbush, J. N., 14
Drake, M., 178
Drewry.W., 173
Druger, P., 173
Dryden, F. D., 5, 6,14
Duffer, W. R., 187
Dupuis, M., 156,172
Dye.E. O., 137,173
Eaton, F. M., 153, 154,155,161,162,163,173
Eaton, S. V., 173
Ehlig,C. F., 155,163,173
Ehrlich, S., 187,189
Eilers, R. G., 212, 213
Elgabaly.M. M., 164,173
Eliassen, R., 137,173
Ellis, G. H., 174
Embleton, T. W., 157,158,173,174,176
Emerson, D. L., 88
Englebert, L. E., 174
Englehard.W.E., 172
Enns, W. R., 157, 175
Environmental Protection Agency, 36,46,75,87,199 200
213
Ergle.D. R., 163,173
Evans, C. A., 172
237
-------
238
Author Index
Falk, L. K., 177
Farrell, M. A., 176
Federation of Sewage and Industrial Wastes Association, 47,
68,71,87
Feinmesser, A., 137,173
Fenn, L. B., 172
Fergus, I. F., 158, 173
Ferris, J. G., 186
Filip, D. S., 71
Fireman, M., 163, 173, 174, 177
Folkman, Y., 31,46, 55,68
Forbes, R. H., 156, 173
Ford, H.W., 158,173
Foree, E. G., 43, 46
Foster, Z. C., 174
Francis, L., 178
Frear, D. E. H., 157, 174
Fruh, E. G., 45, 46
Furman, Thomas De Daussure, 47, 51, 52, 68, 72, 88
Hunt, Henry J., 137,174
Hunt, P. G., 185, 186
Hunter, J.G., 156, 164,174
Hurd-Karrer, Annie M., 162, 174
Husley, A.,188, 190
I
!ves, Kenneth J., 55, 59, 60, 68
J
Jackson, W. A., 174
Jenny, H., 138, 174
Joham, H. E., 157, 174
Johnson, C. M., 152,172
Jones, J. H., 137, 174
Jones, N. B., 69, 146,147, 174, 175
Jones, W. W., 173, 176
Jopling, W. F., 150,158, 174, 175
Joshi, K. G., 159,174
Gallatin, M.H., 175
Garber, M. J., 159,172, 173
Garner, W.W., 157, 174
Gauch, H. G., 157,174, 175
Gausman,H. W., 155, 173
Gearheart, R. A., 137
Gee, H. K., 176
Gilbert, F. A., 163,174
Gile.P. L., 174
Gissel-Nieken, G., 162, 172
Gloyna, E. F., 147, 174
Golueke, C. G., 176
Goudey, R.F., 137, 174
Grantham, George R., 47, 51, 52, 53, 68, 72,1
Greer, D. E., 188, 189
Grossenbecker, K., 138, 174
Guerin, F. J. A., 46
Gupta, U. C., 158.174
Gusta, L. V., 156, 172
H
Hall, E. D., 213
Harding, R. B., 163, 173, 174, 176
Harley, C. P., 152,174
Harlin, C. C.Jr., 185, 186
Harris, D.J., 193,197
Harris, S. E., 71
Harward, M. E., 155,174
Hassan, M. N., 152,154
Hayward,M. L, 137, 174
Henderson, J. P., 189
Henry, A. K., 88
Henry. CO., 137, 174
Herman, E. R., 147, 174
Herzik, G. R.,Jr., 137,174
Heukelekian, H., 137,174
Hewitt, E.J., 156, 157,174
Hill, D., 71
Hill,R.D., 137,174
Hills, F.J., 172
Hinman, J. J. J., 163,174
Hoeppel, R. E., 185, 186
Holmes, R. S., 159,172,174
Hooper, Margerat C., 157, 174
Homer, G.M., 177
Hough, G. J., 162, 174
Huguenin, J. E., 188,189
Kabter, P. W., 166, 176
Kardus, L. T., 176
Katko, A., 175
Keaton, C. M., 177
Keffer, William J., 193, 197
Kelley, S. M., 174
Kelley, W. C., 152, 174
Kelley, W. P., 137, 148,175
Keshen, A. S., 171, 175
Kitterle, R. A., 146, 175
Klein, S. A., 178
Klintworth, H., 157, 175
Krantz, B. A., 172
Kraus, E. J., 158,175
KiaybiU, H. R., 158, 175
Eabanauskas, C.K., 157, 175, 176
LangiUe, W. M., 154,175
Larson, G., 174
Las Virgenes Municipal Water District, 187, 190
Lawrence, A. W., 43, 46
Lehman, W. F., 176
Leone, I. A., 156, 175, 176
Leukel, W. A., 177
Levin, G.V., 31,46
Lewis, R. F., 3
Ueber, M., 154,175
Lieberg. G. F., 152, 175
Lindner, R. C, 152,174
Lipman, C. B., 153, 156,163,175,177
Uttle,G. M,, 137,175
Loneragan, J. F., 159,175
Long, S. K., 68, 87
Lund, Z. F., 155, 175
Lunin.J., 160,175
Lunt, O. R., 176
Lynch, K., 148, 175
M
MacKay, D. C., 174
MacKinney, G., 156,175
Magjstad, 0. C., 160,175
MaHoney, J. F., 154,175
Marais, G. v. R., 147, 148,149,175
Marshal], G. R., 47, 68, 72, 75, 76, 81, 85, 88
-------
Author
239
Martin, D.M., 31,46
Martin, J.L., 31, 37, 46
Martin, J. P., 138,163, 175
Mason, D. D., 174
McCarty, P. L., 45, 46
McCoy, 0. D., 176
McCulloch, R. B., 172
McGarry, M. G., 31,46
McGauhey, P. H., 178
McHargue, J. S., 157, 175
McHarness, D. D., 45, 46
McKee, J. E., 52, 69,154,156, 162, 164,168,175
McKinney, R. E.,5, 14, 15
McLarney,W. O., 189
McLaity, H. R., 154,175
McLean, G. W., 173
McMichael, W. F.,212, 213
McMurtrey, J. E.,Jr., 174
McNulty, I. B., 157,175
McQueen, Frank, 137, 175
Meenaghan, G. F., 147, 175
Meron, A., 155, 165,175
MeneU.J. C, 137, 175
Merz, R.C.,137,138,175
Meyer, B. S., 157,175
Michelson, L. P., 178
Middlebrooks, E. Joe, 47,58, 65, 68, 69, 71, 72, 75, 76, 81,
85,88, 137,144,145, 175
Miller, M. D., 177
Miller, M. P., 174
Miller, W. M., 162, 175
Millikani C. R., 156,176
Mishra, P. C., 153,176
Misra, S. G., 153, 176
Mitchell, George A., 137, 176
Mitchell, R., 176
Moldenhauer, R. E., 174
Mor, E., 176
Moss, E. G., 174
Moxon, A. L., 152,176
Myers, E. A., 176, 184,186
Mulbargei, M., 45
N
National Technical Advisory Committee on Water Qualit;
Criteria, 156, 176
Nesbitt, J. B., 176
Nevo, Z.,137,172,176
Newman, D.W., 157, 175
Norman, N. N., 166, 176
0
O'Brien, W.J., 31,46
Oertli.J.J., 153,172,176
Ohki, K., 159, 177
Olgyay, V., 149,176
Olson, E. 0., 173
Olson, 0. E., 176
O'Melia, C, E., 31,45,55,68
Ongerth, H.J.,165,177
Ort,J. E., 31,46
Oswald, W. J., 146, 147, 149, 151, 176
Overman, A. R., 170, 176
Overstreet, R., 152,174
Parizek, R. R.,137,176
Parker, C. E., 5,14
Parker, D. S., 31, 46
Parsons, T. R., 50, 69, 75, 88
Patwardham, S. D., 174
Paul,J. R., 137, 176
Pearson, G. A., 163,172
Peech, M., 173, 178
Peterson, H. B., 158, 160,176, 177
Peynado, A., 173
Pierce, D. M., 89
Piland, J. E., 174
Pincince, Albert B., 52, 69
Pintler, H. E., 175
Pipes, W.O., Jr., 147, 176
Porter, L. K., 152,176
Pound, C.E., 184,185,186
Pratt, P. F., 158,176
Preston, C., 152,177
Prince, A. L., 176
Prokopovich, N. P., 188,190
R
Rafter, George W., 137, 176
Ragotzkie, R. A., 177
Raleigh, G.J., 155,176
Ramati, B., 176
Rebhun, M., 175
Reid, G. W., 172
Resnicky, J.W., 172
Reuther, W., 158, 159, 173, 176
Reynolds, J. H., 69, 71, 174, 175
Richards, S. J., 163, 175
Riney.W. A., 137,176
Robins, W. R., 175
Robinson, F. E., 160, 176
Rohde, G., 138, 176
Rosenkranz, W. A., 1
Rossiter, R. C.,159, 176
Roth, J. A., 176
Rubeck, G. G., 174
Rudolfs, Willem, 137, 166,176, 177
Rust, A., 189
Ryan, W., 173
Rytler, J. H., 188, 189, 190
Salisbury, P. J., 178
Schroeder, H. A., 154,177
Schwartz, W. A., 177
Scofield, C. S., 163, 177
Searight.W. V., 176
Shell, Gerald L., 69, 175
Shindala, A., 31, 46
Simonds, J. O., 149,177
Sisson, L. L., 176
Skulte, Bernard, P., 137, 177
Sless, B., 175
Smith,?. F., 173, 176,177
Smith, R., 199, 212, 213
Snider, H.J., 158,177
Soloranzo, L., 50, 69, 75, 88
Somers, G. F., 174
Sommer, Anna L., 163,153,177
Specht, A. W., 172,177
State Water Pollution Board of California, 138, 177
Stefferud, A., 149,177
Stern, G., 5, 6,14
Steward, F. C., 152,177
Stewart, B. A., 138,177
Stewart, J.W., 31,46
Stokes, W. E., 137, 177
Strickland, J. D. H., 50,69, 75,78
-------
240 Author Index
Sullivan, R. H., 184, 186
Supper, W.E., 176
Sutherland, F. H., 172
Taylor, A. W., 138, 177
Taylor, G, S., 166, 174
Tchobanoglous, G,, 173
Tenny, M. W., 31,46
Thakui, P, S., 174
Thomas, R. E., 137, 166,177, 183,185,186
Thorne, D.W., 152, 158,176, 177
Tiffin, L O., 172
Tofflemire, T. J., 186
Trask, J. D., 137, 176
Trelease, Helen M., 162, 177
Tielease, S. F.,162, 177
Trimberger, J., 188, 190
Truog, E., 162,174, 177
Tucker, T.C., 137, 171, 173
Tylei, R. W,, 176
U
Uhte,W. R., 21
Ulrich, A., 159, 177
U.S. Geological Survey, 46
U.S. Public Health Service, 151, 177
U.S. Salinity Laboratory, 138, 177
Utah State Division of Health, 152, 177
Vandecaveye, S. C., 151, 177
Vanselow, A. P., 153, 162, 173, 175, 177
Vavich, M. G., 173
Vennes.J. W., 14
Veignano, Ornella, 156, 164,174
W
Wachs, A.M., 31,46,55, 68
Wadleigh, C. H., 153, 157,174, 175,177
Waksman, S. A., 138, 175
Wallihan, E. F., 157,177
Walter, CM., 191
Ward, P. C., 165,177
Warrington, Sam L., 137,177
Water Resources Council, 213
Weller, R., 31, 37, 46
Wells, W.N., 137, 177
Welsch, W. F., 154, 175
Werkhoven, C. H. E., 161, 163,177, 178
Whetstone, R. R., 152, 178
Wilcox, L.V., 137,159,173, 178
Williams, K.T., 152,178
Williams, T. C, 184, 186
Winkelstein, W., Jr., 174
Winneberger, J. H., 137, 178
Winsser, J., 174
Wolfe, H. W., 154, 156, 162, 164, 168,175
Woodbridge, C. G., 154, !75
Worker, G. F., Jr., 176
WPCF, 87
Wright, C. T., 166, 178
Yogt.J.E.,137, 178
York, E.T., Jr., 137, 155,178
Younger ,V. B., 176
Zanoni, L.J., 158,172, 178
Ziebell, C. D.,188, 189
-------
SUBJECT INDEX
Aerated lagoons, 132
Aeration, 22
Aerobic zone, 11, 20
Algae, 1,6,8,17,18,51,74
Actinastrum, 18
Anabaena, 18
Anabaena sp., 85
Ankistrodesmus microactinium, 18
Aphanocapsa sp., 85
Blue green coccoid, 75
Carteria, 18
Cell count, 10
Chlamydomonas, 18
Chlamydomonas sp., 85
Chlorella, 18
Chlorogonium, 18
Closterium, 18
Euglena, 18
Euglenoid, 75
Food supplement, 6
Green, unicellular, 75
Growth, 78
Miciocystis sp., 75
Navicula, 18
Naviculasp., 75
Oscillatoria, 18
Oscillatoria sp., 75
Pandorina, 18
Pediastrum sp., 75
Pennate, 75
Phacus, 18
Phormidium, 18
Primary, 18
Removal, 6, 72, 85
Scenedesmus, 18
Schoideria sp., 75
Algae removal
Biological harvesting, 187
Algal removal, 55, 75
Alkalinity, 10, 17, 45
Bicarbonate, 152
Carbonate, 152
Alum
Phosphorus removal, 13
Aluminum, 170
Ammonia nitrogen, 10,17, 34, 37, 38, 39, 40, 45, 75, 80, 81,
83,85, 126,127,132
Increase in effluent, 45
Anabaena, 51
Anaerobic zone, 11
Ancillary facilities
Boat ramps, 25
Flow measurement, 25
Housing, 25
Samplers, 25
Arsenic, 152,170
Arctic Research Laboratory, 5
Arctic Environmental Research Laboratory, 227
Attendees
Symposium, 231
B
Bacteria
Achromobacter, 18
Coliform, 18
Flavobacterium, 18
Primary, 18
Pseudomonas, 18
Removal, 58
Bacteriological analysis
Form, 97
fielding, Michigan, 125,126,127, 129
Beryllium, 170
Best practicable technology, 199
Bioassays
Algal, 5 8
Biochemical oxygen demand, 10, 15, 34, 36, 37, 52,53,54,
59, 73, 75, 80, 82, 85, 97, 98, 120, 126, 127, 129,
132,133,191,193
Removal, 4,5
Soluble, 10, 37, 38, 39, 40
Total, 10, 37, 38, 39, 40
Biological harvesting, 187
Algae, 187
Bivalve mollusks, 188
Fish, 188
Research needs, 189
Zooplankton, 188
Biomass removal
Algal, 79
Blanding, Utah, 178
Blue Springs, Missouri, 9, 191
Boron, 153, 170
Cadmium, 154,170
Calcium, 154
California, Missouri, 39,43
Capital costs, 216, 217, 218, 219, 221, 223,225
•Design capacity, 216, 217, 218, 219, 221, 223, 225
Cash flow, 204
Cell count.10
Algae, 10
Charges
Engineering fee, 27, 28
User, 28
Chemical oxygen demand, 10, 34, 36, 73, 75,80, 85,193
Soluble, 10, 37, 38, 39, 40
Total, 10, 37, 38, 39, 40
Chlamydomonas, 51
Chlorella, 38
Chloride, 155
Chlorination, 2,11.130, 133,134
Chlorine residual, 12
Chlorophyll, 34, 37, 38, 39,40,194
Chromium, 170
Cincinnati, Ohio, 2, 3
Clogging
Soil, 166
Soil pores, 137
241
-------
242 Subject Index
Cold climate
Aerated, 227
Lagoons, 227
Coliform, 1, 2,12, 18, 133, 194
Fecal, 5, 10,11,12, 98,129,194
Reductions, 18
Removal, 97
Configuration, 23
Construction
Considerations, 26
Contract requirements, 26
Drawings, 26
Equipment lists, 26
Procedures, 21
Construction cost index
Sewers, 202
Continuous cash flow, 204, 205
Contract requirements, 26
Copper, 156
Corinne, Utah, 9, 10
Costs, 3, 43, 65, 66, 67, 199, 200, 202
Cost-effectiveness analysis, 199
Cost estimate
Lagoons, 224, 225
Crop irrigation, 6,13
Lagoon effluent, 183
Crop usage
Lagoon effluent irrigation, 171
Crops
Effects of lagoon effluent, 137
D
Daphnia, 37,51
Denitrification, 201
Design
Ancillary facilities, 25
Configuration, 23
Criteria, 19
Dike construction, 25
Features, 89
Housing, 25
Infiltration-percolation systems, 185
Inlet, 24
Intermittent sand filters, 47, 74
Irrigation, 184
Lagoon, 89,145
Liners, 73
Media, 49
Operation, 27
Outlet, 24
Overland-flow, 185
Parameters, 90
Population projections, 29
Recirculation, 23
Rock filter, 32, 33, 44
Scum control, 24
Design capacity, 216, 217, 218, 219, 221, 223
Capital costs, 216, 217, 218, 219, 221, 223
Detention time, 36
Diatoms, 51
Dike construction, 25
Discharge
Control, 91
Controlled, 134
Patterns, 92
Report, 99
Disinfection, 1,2, 11, 14
Chlorination, 130
Lagoon,12
Dissolved oxygen, 75, 85,126,127
Drawdown, 19
Drinking water
Livestock, 181
Economics
Lagoon construction, 21
Effective size, 86
Effluent
Algal laden, 1, 6
BOD, 4
Crop irrigation, 183
Disinfection, 1,2
Lagoon, 1, 6, 13, 169
Land application, 1,13
Suspended solids, 4
Effluent quality, 77, 97, 125, 132, 177, 178, 179, 180,192
Seasonal trends, 114
Variation with time, 80
Endogenous respiration, 16, 17
Environmental Protection Agency, 1, 2, 3, 6, 8, 9, 13, 15, 36,
87,191, 207, 227, 229, 234
Eudora, Kansas, 7, 9, 31, 32
Euglena, 51
Eutrophication, 6
Evaporation, 19, 20
Fargo, North Dakota, 132
Filters
Gravel-activated carbon, 229
Intermittent, 1, 6, 11, 13, 47, 49, 60, 61, 62, 71, 72,
82, 85, 86
Rock, 1, 6, 13, 31, 32, 33, 35, 37, 40, 44
Flow rates, 8
Fluorescence, 56
Fluorine, 156, 170
Future worth, 204
Gravel-activated carbon filter, 229
Genoa, Ohio, 12,13
H
Harvesting
Algae, 187
Biological, 187
Bivalve mollusks, 188
Fish, 188
Research needs, 189
Zooplankton, 187
Hydraulic loading rate, 36,48,50.52,54,55, 56, 57, 61, 72,
73,79,81,82,83,84,85,92
Hydrogen sulfide, 43
I
Illinois, 130
Infiltration-percolation, 184,185
Inlets, 24
Inspection, 27
Interest charges, 208
Intermittent sand filters, 1, 6,11, 47, 71, 72, 74
Bacterial removal, 57
Cleaning, 73, 75
Cost, 65, 66, 67
Design, 47
Evaluation, 65
History, 47, 71
-------
Subject Index 243
Hydraulic loading, 48
Laboratory, 47,72
Performance, 82, 85
Period of operation, 60, 61, 62, 63, 75
Pilot, 47, 72
Plugging, 59
Series, 86
Solids removal, 56,57
Underdrain, 48
Intermittent sand filtration, 13
Iron, 157,170
Irrigation, 151, 185
Case history, 171
Crop usage, 171
Effluent use, 130
Lagoon effluent, 137
Land required, 170, 171
Public health aspects, 165
State standards, 165
K
Kilmichael, Mississippi, 9, 10
Lagoons
Aerated, 1, 13, 14, 15, 18, 22, 132, 223, 227
Area, 22
Cold climate, 227
Configuration, 23
Continuous discharge, 8
Design, 2, 3, 7, 8, 15, 16, 19, 21, 22, 71, 89,145
Design parameters, 90
Dike construction, 25
Disinfection, 11,14
Drawdown, 19, 89
Economics, 145,146,191,220,221,222,223,224,225
Facultative, 3, 4, 7, 8, 10, 12, 14, 22
Flow rates, 1,8
Inlets, 24
Level of treatment, 1, 22
Maintenance, 1, 3, 21, 27
Microbiology, 18
Minimum sampling, 235
Monitoring requirements, 233, 235
Multi-cells, 7, 8,10, 22,120,129,134
Nitrification, 13, 14
Non-discharge, 1
Number in use, 3,71
Operation, 21,22,90
Operational problems, 6
Outlets, 24
Oxidation, 1,15,18
Parallel, 8, 22
Performance, 3,4,5,8, 11, 22,89,100, 169,192,194,
195
Recirculation, 23
Series, 8, 22
Short circuiting, 3
Size, 1, 3, 8,16,19
Soil mantle disposal, 137
Supplemental treatment, 1
Surface area, 90
Suspended solids removal, 4,5,10
Tertiary, 22,49,131,134
Upgrading, 1, 31, 72, 236
Wastewater treatment, 15, 71
Weed control, 6
Land application, 1, 6,183, 185, 186
Land disposal, 13
Land use
Planning, 147
Site selection, 147
Lead, 157, 170
Light
Effect on operation,??
Liners, 73
Lithium, 170
Livestock
Drinking water quality, 181
Loading
Hydraulic, 36, 48, 50, 52, 54, 55, 56, 57, 61, 72, 73,
79,81,82,83,84,85,92
Organic, 3, 16, 92
Loading rates, 22
Organic, 8
Logan, Utah, 7, 11,49,73
M
MPN, 12, 123
Magnesium, 157
Manganese, 157, 170
Maps
USA, 9
Michigan, 100,124
Microbiology, 18
Molybdenum, 170
Monitoring
Requirements, 233
Municipal bonds, 207
Municipal wastewater treatment
Needs, 210, 211
N
Nickel, 170
Nitrate nitrogen, 10, 12, 75, 80, 81, 84, 85,126, 127,194
Nitrification, 11, 13, 14, 81, 126, 134
Nitrite nitrogen, 10, 75, 80, 81, 84, 85
Nitrogen, 51,158
Ammonia, 10, 12, 17, 34, 37, 38, 39,40,52,53,75,
80, 83, 85, 126,127,128,132
Nitrate, 10,12, 52, 53, 75, 80, 84, 85,126, 127,194
Nitrite, 10,12, 75,80, 84, 85
North Dakota, 124
O&M manuals, 27
Odors, 3, 6
Operation, 27
Discharge, 92
Intermittent sand filters, 75,76, 77
Lagoon, 90
Period of, 60, 61, 62, 63, 72, 77
Records, 91,93
Operator training, 28
Organic loading, 16
Outlets, 24
Overland-flow, 185
Design, 185
Oxygen, 17,18
pH, 5,18, 37, 38,49. 75, 85,126,132, 194
Performance, 3,4,5,8,192
Evaluation, 8,10, 28
Intermittent sand filter, 82,85
Lagoons, 89, 97,100,123,125,127,169
Multi-cell lagoons, 120
Seasonal, 127,128,133
Seasonal trends, 114
Soil mantle systems, 137
-------
244 Subject Index
Peterborough, New Hampshire, 9, 11
Phosphorus, 34, 37, 38, 39, 40, 158
Alum, 13
Orthophosphate, 75, 81, 126
Removal, 13
Sludge, 13
Total, 75, 81, 126, 129,132
Photosynthesis, 23
Phytoplankton, 195
Planning
Examples, 149,150
Lack of, 5
Techniques, 149,150
Population projections, 29
Potassium, 159
Present value, 204
Protozoa
Colpidium, 18
Euplotes, 18
Glaucoma, 18
Paramecium, 18
Vorticella, 18
R
Recirculation, 23
Reed City, Michigan, 133
Regions
Great Lakes Basin, 4
Middle Atlantic, 4
Missouri Basin, 4
Northeast, 4
Northwest, 4
Ohio Basin, 4
South Central, 4
Southeast, 4
Southwest, 4
Reports
Operating, 93
Research and development, 2
Retention period, 19
Rock filter, 13
Ammonia nitrogen increase, 45
Costs, 43
Design, 44
Gradation, 43
Hydrogen sulfide production, 43
Solids buildup, 40
Roosevelt, Utah, 178
Rotating biological contractor, 12
Rotifers, 18
Silver, 162
Sludge
Buildup, 13
Sludge handling, 214
Sodium, 162
Soil
Analysis, 143
Bridging, 138
Clogging, 166
Permeability, 138
Sedimentation, 138
Straining, 138
Soil mantle treatment, 137, 183
Solids buildup, 40
South Dakota, 236
St. Charles, Maryland, 13
Storage
Long range, 134
Storm water, 201
Sulfate, 163, 164
Surveillance, 3
Suspended solids, 10
Removal, 4, 5, .187
Total, 12, 34, 36,37, 38, 39,40, 48, 50, 55, 56, 57, 75,
76, 77, 78, 80, 85, 97,120, 126,129,132,133,
137
Volatile, 12, 34, 36, 37, 38, 39, 40, 50, 55, 56, 57, 75,
76,78,80,82,85,120
Symposium
Membership, 231
Synthesis, 16,17
Technology transfer
EPA, 6
Temperature, 19, 36, 195
Tertiary lagoons, 131
Toxicity
Plants, 168
U
University of Kansas, 17
Upgrading, 31, 32, 37
Algae removal, 6
Wastewater ponds, 1, 2, 5
Utah
Water quality standards, 144, 145
Utah State University, 2, 11, 48, 72, 86, 141
Salinity, 160.161
Sampling, 8, 7 3
Minimum frequency, 235
Sand
Effective size, 49,50, 72, 86
Scum control, 24
Seasonal variation
Performance, 127
Secondary treatment
Standards, 1,5,8
Selenium, 162, 170
Settleable solids, 20
Sewers
Pressure, 2
Vacuum, 2
Short circuiting, 3
Sieve analysis, 7 3
Silica, 162
Vanodium, 170
Volatile suspended solids, 10
W
Wastewater treatment, 15
Biological concepts, 16
Water pollution, 6
Water pollution control
Cost-effectiveness, 199
Water quality
Factors, 167
Weeds
Control, 6
Zinc, 163, 170
Zooplankton, 75, 187
Algae harvesting, 187
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