ECHNOLOGY
The Bridge Between Research and Use
W-
U.S. ENVIRONMENTAL PROTECTION AGENCY
OCTOBER 1, 1374
NEW SLUDGE TREATMENT AND
DISPOSAL DESIGN MANUAL TO BE
FEATURED AT WPCF CONFERENCE
The EPA Technology Transfer Program will once
again participate in the annual conference of the
Water Pollution Control Federation being held this
year in Denver, Colorado, in October.
The new Technology Transfer Process Design
Manual for Sludge Treatment and Disposal will be
introduced and distributed at the Denver meeting.
There will be no charge for this new "blue book."
The new sludge manual will be comprehensive in
scope and include such topics as physical and
chemical properties, thickening, stabilization,
conditioning, dewatering, reduction, final disposal
processes, and case studies. New chemical sludges
and oxygen sludges will be covered in addition to the
various types of equipment required to perform the
basic processes. All new processes and equipment
will be included as well as cost data and all
applicable data and information from the EPA
research and demonstration program.
Host region for this years conference will be EPA's
Region VIII. John A. Green, the Regional
Administrator, will be on hand at the opening of the
conference, which annually attracts thousands of
the nations top pollution experts.
On October 3,1971, John A. Green was appointed
as the first Regional Administrator of the
Environmental Protection Agency, Rocky Mountain-
Prairie Region, by EPA National Administrator,
William D. Ruckelshaus.
As Regional Administrator, Green is the highest
level federal official concerned with protecting the
environment in the states of Colorado, Utah,
Montana, Wyoming, North Dakota, and South
Dakota. He is responsible not only for the agency's
leadership in environmental management, but, also,
for planning and integrating important strategies
and priorities in the six-state region. Green directs
the development and administration of a coherent,
unified approach to the interrelated problems of atr
and water pollution, pesticides, radiation, solid
waste and noise.
Immediately prior to being appointed Regional
Administrator, Green served as senior staff advisor
John Green, EPA, Region VIM. Administrator
to the EPA Assistant Administrator for Categorical
Programs in Washington, D.C. Green was
responsible for guiding the program's control of a
wide variety of environmental contaminants,
including pesticides, radiation, and solid waste.
Green has also served as Director of Management,
Federal Water Quality Administration in Arlington,
Virginia. As Director, Green supervised special
studies aimed at improving the efficiency and
effectiveness of the nation's "Clean Water" program
as well as overseeing the development of a
long-range strategy for the attainment, nationally, of
the Federal Water Quality Standards.

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Systems
SULFIDE CONTROL MANUAL AVAILABLE
The Technology Transfer Process Design
Manual for Sulfide Control in Sanitary Sewerage
Systems, prepared by Pomeroy, Johnston, and
Bailey of Pasadena, California, is currently being
distributed. This Manual includes information for all
feasible alternative designs that can be used to
control sulfides and minimize their effects in both
new and existing sewerage systems.
Specific topics covered include: Characteristics
and Properties of Hydrogen Sulfide; Occurrence
and Effects of Sulfide in Sewers; Investigation in
Existing Systems; and Design of Sewer Systems to
Prevent Sulfide Problems. Case histories, examples,
and cost estimates are presented to substantiate
the "how-to" approach of this manual.
Individuals interested in obtaining, at no charge, a
copy of the Sulfide Control Manual should fill out the
appropriate form in the back of this publication and
forward it to Technology Transfer, U.S. Environ-
mental Protection Agency, Washington, D C. 20460.
INDUSTRIAL SEMINAR PUBLICATIONS
ON UPGRADING MEAT PACKING TO
REDUCE POLLUTION NOW AVAILABLE
A three part publication covering In-Process
Modification and Pretreatment, Waste Treatment,
and Choosing the Optimum Financial Strategy is
now available These publications follow others
developed from the seminar program where
technical sessions were given covering the above
topics. Previous publications were on Reducing
Pollution in the Metal Finishing Industry and the
Poultry Industry.
The publications are particularly oriented toward
owners, managers, superintendents, and engineer-
ing and operating staffs of meat packing facilities.
The seminars and the publications are intended to
inform the small industry of the varied in-plant
process modifications and control alternatives
available to meet environmental standards.
Addressing these topics should help the facility
formulate their control alternatives prior to detailed
design considerations.
To order these publications, use the order form at
the rear of this publication.
TECHNICAL CAPSULE REPORT ON
POLLUTION ABATEMENT IN A BREWING
FACILITY NOW AVAILABLE
A technical capsule report on the
pollution abatement program progress Adolph
Coors brewing facility at Golden, Colorado is now
available.
The report spotlights the achievement made by
Coors in waste reduction, water reuse, and
by-product recovery and utilization. The report
shows the significant savings that can be realized
through a well planned and well executed
environmental control and resource conservation
program. Through these efforts Coors has realized a
savings of more than $1,500,000 in treatment plant
capital costs and a savings of nearly $1,500,000 per
year in treatment plant operating costs. The success
of the Coors environmental control program is due,
to a great extent, to the strong support given by
William K. Coors and his management staff.
The process design improvements and in plant

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changes made by Coors to reuse water, reduce waste
loads and recover by-products are directly
applicable to other breweries as well as other food
processing industries.
To order your copy of this capsule report, use the
order blank on the back page.
NEW MUNICIPAL SEMINAR
PUBLICATIONS AVAILABLE
Three new Technology Transfer municipal
seminar publications have been published and are
now available for distribution. These publications
include material developed for the design seminar
program and have been used throughout the
country. The new seminar publications, which may
be ordered by using the request form at the rear of
this newsletter, include the following:
"Flow Equalization" by Metcalf & Eddy Engineers
(Stanley Elkerton, primary author). This publication
includes determination of equalization require-
ments, design and construction procedures,
equalization impact on other treatment compo-
nents, costs, and four selected case histories.
"Wastewater Filtration" by John Cleasby and
Robert Baumann. This publication includes most
aspects of filter design including filter
configurations, methods of flow control, backwash-
ing requirements, headloss development, and
selection of filtration rates.
"Physical-Chemical Nitrogen Removal" by Culp
Wesner, and Culp (Gordon Culp primary author).
Included in this publication are design
considerations for the three feasible physical-chem-
ical methods of nitrogen removal, i.e. selective ion
exchange, ammonia stripping, and break point
chlorination Chapters include information on
typical design criteria, pilot testing, case histories,
costs, and basic comparison of the three processes.
MUNICIPAL DESIGN SEMINARS
Five additional Technology Transfer municipal
design seminars have been conducted in various
areas of the country since publication of the last
newsletter. These were presented in Newark, New
Jersey, March 13-15; San Juan, Puerto Rico, April
8-10; Orlando, Florida, May 7-9; Seattle,
Washington, May 21-22, and Boston, Massachusetts,
September 10-11.
The Newark, N.J. seminar included technical
sessions on nitrogen control, upgrading existing
wastewater treatment plants, and combined sewer
overflows. The nitrogen control session was
especially well received with Dr. Clair Sawyer
covering biological nitrification and denitrification
and Mr. Gordon Culp covering physical-chemical
nitrogen removal. They were assisted by Mr. Don
Ehreth of the EPA Office of R&D.
The San Juan, P R. seminar included technical
sessions on sludge treatment and disposal and
upgrading existing trickling filter plants. In addition
to the technical session, a general first day session
covered the EPA municipal construction program,
construction design guidelines and EPA regional
grants program and procedures. EPA speakers at
this session included Mr. Harold Cahill and Mr.
Charles Sutfin of the Office of Water Programs
Operations, and Mr. Rocco Ricci of EPA Region I.
This seminar was held with the cooperation of the

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Attendees of the Orlando, Florida. Seminar.
Puerto Rico Environmental Quality Board and the
Puerto Rico Aqueduct and Sewer Authority.
The Orlando, Fla. seminar included sessions on
oxygen aeration, nitrogen control and upgrading
existing treatment facilities. The opening morning
general session included discussions of user
charges, construction guidelines, and municipal
permits.
The Seattle, Wash, seminar featured two full day
sessions on sludge treatment and disposal and
infiltration/inflow control. The sludge session
featured three of the key individuals involved in
preparation of the forthcoming Technology Transfer
sludge design manual (see story on 1st page); Dr.
Jim Smith of the EPA National Environmental
Research Center, Cincinnati; Mr. Jack Harrison of
Black, Crow, and Eidness Engrs; and Mr. Gordon
Culp of CWC Consultants.
The Boston, Mass. seminar featured the first full
day nitrogen control session conducted at a T.T.
seminar with presentations by Dr. Clair Sawyer, Dr.
Denny Parker, Gordon Culp, Don Ehreth and Ed
Barth. Technical sessions were also conducted on
physical-chemical treatment and phosphorus
removal.
Key presentations by other speakers at the above
seminars were given by Dr. Denny Parker and
Warren Uhte, Brown and Caldwell; Dr. Bob
Baumann and Dr. Jack Cleasby, Iowa State
University; Charles Hansen, Envirex; James
Laughlin, Shimek, Roming, Jacobs & Finklea; Ariel
Thomas, Metcalf & Eddy; Curt McDowell, Air
Products; Mike Miller, Union Carbide; Bob Pfefferle
and Tom Clark, American Consulting Service; and
Jon Dyer, Ed Barth, Dick Field and Jesse Cohen
from the EPA R&D staff.
SEMINAR SERIES POLLUTION
ABATEMENT IN METAL FINISHING
FACILITIES
The sixth in a series of Technology
Transfer seminars on "Upgrading Metal Finishing
Facilities to Reduce Pollution" was held in Chicago,
Illinois on May 7-8, 1974.
The first session of the seminar featured a
welcome address by Francis T. Mayo, Administrator
for EPA's Region V, and an address by Simon P. Gary
of the American Electroplaters Society on the impact
of the Water Pollution Control Act on the plating
industry. Following these addresses, Quentin h
Pickering of the EPA Newtown Fish Toxicology
Station gave a presentation on the effects of Heavy
Metals on the Aquatic Environment.
The first major technical sessions covering In
Process Pollution Abatement was presented by Alan
E. Olsen of Oxy Metal Finishing and Ed Hanf of the
Culcote Company. This session covered in-plant
water reduction, waste load reduction, spill
prevention and control, and air emission control.
The sessions on Waste Treatment Systems was
presented by Dr. Leslie E. Lancy and Fred Steward
of Lancy Laboratories. This session included a
review of the proven waste treatment alternatives
as well as a presentation by Dr. Lancy on
Liquid-Solid Separation Solids Concentration and
Sludge Disposal.
The final session featured a presentation on
Optimum Financial Strategy by Charles R. Marshall
of J. A. Commins and Associates and a review of the
EPA Demonstration Grant Program by John Ciancia
of the Edison Water Quality Laboratory. In this

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session John Ciancia covered the status of emerging
technology for treatment of metal finishing wastes.
POLLUTION CONTROL SEMINAR
FOR THE SEAFOOD INDUSTRY
Technology Transfer in cooperation with the
National Fisheries Institute and the National
Canners Association held its first two seminars for
the seafood processing industry entitled "Up-
grading Seafood Processing Facilities to Reduce
Pollution" in New Orleans, La. on May 5-6, 1974, and
in Seattle, Washington on April 2-3, 1974.
The seminars featured addresses by Roy Martin of
the National Fisheries Institute and Allen
Katsuyama of the National Canners Association.
The emphasis for the two-day seminars was on the
sessions concerning In-Plant Control of Wastes and
Waste Treatment Systems. The session on In-Plant
Control featured Dr. George Piggott of the
University of Washington's Institute for Food
Science. The session on waste treatment featured
Michael Soderquist of Environmental Associates,
Inc. The treatment session included informative
presentations on the latest progress in waste
treatment demonstration projects, presented by
Fred G. Claggett of Canada's Envrionmental
Protection Service, A. Frank Mauldin of Dorminique,
Szabo and Associates, and Irwin F. Snyder of
Carborundum Envrionmental Systems, Inc.
The seafood processing industry was represented
by Roy Martin of the National Fisheries Institute in
his talk on Future Considerations of Seafood
Technology, and by Allen Katsuyama of the National
Canners Association in his talk on Effective
Government-Industry Relationships to Control
Pollution.
The final session of the seminars featured
presentations on Optimum Financing Strategy by
Charles R. Marshall of J. A. Commins and
Associates, and a discussion on the EPA
Demonstration Grant Program by Kenneth Dostal
and Harold Thompson of the EPA Waste Treatment
Research Program in Corvallis, Oregon.
MONITORING AND TOXIC SUBSTANCES
CONTROL SEMINARS
Technology Transfer held its first
seminars for industry on Monitoring Industrial
Wastewater and Toxic Substances Control in
Atlanta, Georgia on April 18 and 19, 1974
The Monitoring Seminar, attended by 300 plant
managers, featured a welcome address by John C.
White, EPA Deputy Regional Administrator.
The morning session of the seminar covered EPA
regulatory policy with regard to the monitoring
requirements of PL 92-500. Florida, Kentucky,
Audience at Technology Transfer Monitoring Seminar held in Atlanta, Georgia.

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Asa Foster, Technology Transfer Chairman for Region IV,
addresses Monitoring Seminar in Atlanta. Seated from left to
right are Wesley Eckenfelder, of Aware, Inc., and Walter Zabban,
of Chester Engineers.
Georgia, Mississippi, North Carolina, South Carolina,
and Tennessee presented the states' relationship to
the Federal Program.
The afternoon session offered technical guidance
for implementing a monitoring program. Dr. Wesley
Eckenfelder of Vanderbilt University and AWARE,
Inc. concentrated on an overview of Monitoring
Industrial Wastewater. Dr. Phillip Shelly of
Hydrospace-Challenger discussed Sampling, The
session on Flow Measurement was presented by Vic
Jelen of the EPA Cincinnati Field Investigation
Center. The session on Analytical Quality Control
was prepared by Robert Booth of the EPA Cincinnati
Methods Development and Quality Assurance
Research Laboratory. The final session on
In-Process Monitoring was presented by Walter
Zabban of Chester Engineers.
The Toxic Substances Control seminar was
presented on the following day. The first session was
devoted to presenting an overview of the Toxic
Substances Provisions of PL 92-500 and EPA's
regulatory policy toward Toxic Substances.
The final morning session was a presentation on
how permits are processed for toxic substance
discharges.
The second session was designed to present to
the participants of the seminar a comprehensive
discussion on Guidance for Implementing a Control
Program. Charles Sercu of Dow Chemical Company
began this session with a talk on Industry's
Responsibilities in Toxic Pollutant Effluent
Standards. Donald A. Baehl of Union Carbide
Corporation prepared the session on Minimizing
Toxics in Effluents by Process Design and In-Plant
Operating Practices. The next presentation was by
Don Hager of Calgon Corporation who discussed
Activated Carbon Adsorption of Aldrin, Diedrin,
Charles Sercu of Dow Chemical addresses Atlanta Technology
Transfer Seminar on Toxic Substances Control.
Endrin, PCB's, DDT and Toxaphene. The session on
the Control of Cadmium and Cyanide was prepared
by Alan E. Olsen of OXY Metal Finishing.
Control of Benzidene was the subject of the next
session by Thomas Kopp of EPA's Office of Toxic
Substances.
Dr. Lloyd Falk of DuPont Corporation completed
the seminar with a presentation on Dispersion
Techniques.
NEW TECHNOLOGY TRANSFER
MOTION PICTURE AVAILABLE—
"THE SEATTLE METRO STORY"
Another motion picture is now available
through the Technology Transfer Program. The 28
minute, 16 mm color sound film depicts the
development of Seattle, Washington METRO
interceptor system and treatment facilities and their
role in abating pollution of Puget Sound and Lake
Washington. The film features the phosphorus
removal facilities at the Rentin treatment plant;
computer control of combined flow overflows in the
interceptor system; use of sludge from the plant
centrifuges as landfill; and development and
formation of the METRO itself. The film was made
possible by the cooperation and efforts of the
Seattle METRO staff and the EPA Region X staff in
Seattle.
Requests for loan of this film, and other
Technology Transfer films listed on the request form
at the rear of this newsletter, may be made to the
appropriate Technology Transfer Regional Chair-
man also listed at the rear of this publication.

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Left to right: Dennis Cannon, Paul Minor and Jim Truettofthe
Technology Transfer Staff participating in the WWEMA Confer-
ence.
TECHNOLOGY TRANSFER PARTICIPATES
IN WWEMA CONFERENCE
AND EXPOSITION
Technology Transfer participated in the
Waste Water Equipment Manufacturers Association
(WWEMA) annual meeting in Detroit on April 1-4,
1974, with a presentation of Technology
Development by Paul Minor and an exhibit featuring
the industrial seminar publications for the meat
packing, metal finishing and poultry industries, the
industrial technical capsule reports and the
Handbook on Monitoring Industrial Wastewater.
FUTURE MONITORING SEMINARS
A Monitoring Industrial Wastewater
Seminar was held on April 18, 1974, in Atlanta.
See article on page 5 of this Newsletter. This
seminar was an overwhelming success as
measured by the attendance, and feedback
obtained since the seminar. Technology
Transfer is planning to present 10 additional
Monitoring seminars - one in each EPA Region -
during this fiscal vear. Final dates and locations
have not yet been finalized. If you are interested
in attending one of these seminars, contact your
Regional Technology Transfer Chairman listed
in this Fact Sheet.
TEXTILE SEMINAR PUBLICATIONS
FEATURED AT THE INTERNATIONAL
TEXTILE EXPOSITION
Technology Transfer will provide an
exhibit at the International Textile Exposition
(ITEX) in Greenville, South Carolina on October
21-25,1974. The exhibit will feature the distribution
of a two part publication series on "Upgrading
Textile Operations to Reduce Pollution" which were
developed for the Technology Transfer seminar for
the textile industry. The publications cover "In-Plant
Control of Pollution" and "Wastewater Treatment
Systems". Volume one on In-Plant Control was
prepared under the direction of the Institute of
Textile Technology by experts within the Textile
industry. Volume two on waste treatment was
prepared by Metcalf & Eddy Inc., consulting
engineers.
Asa B. Foster Jr., Technology Transfer Chairman
for EPA Region IV in Atlanta and several Regional
representatives will participate in the ITEX
exhibition.
For your copy of these publications, use the order
form on the back of this newsletter.
FLOW EQUALIZATION*
GENERAL
The primary objective of flow-equalization
basins for municipal wastewater plants is simply to
dampen the diurnal flow variation, and thus achieve
a constant or nearly constant flow rate through the
downstream treatment processes. A desirable
secondary objective is to dampen the concentration
and mass flow of wastewater constituents by
blending the wastewater in the equalization basin.
This results in a more uniform loading of organics,
nutrients, and other suspended and dissolved
constituents to subsequent processes.
Through achieving these objectives, flow
equalization can significantly improve the
performance of an existing treatment facility, and is
a useful upgrading technique. In the case of new
plant design, flow equalization can reduce the
required size of downstream facilities.
Variations Of Flow Equalization
Equalization of municipal wastewater flows may
be divided into three broad categories:
•Equalization of dry weather flows
•Equalization of wet weather flows from separate
sanitary sewers
•Equalization of combined storm and sanitary
wastewater
This discussion is primarily concerned with
equalization of dry weather flows. This procedure
* Extracted from "Flow Equalization" prepared for
the EPA Technology Transfer Seminar Publication
Series. Use the form at the rear of this newsletter for
a copy of the complete publication.

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provides a technique for achieving normal operation
of a treatment plant under near ideal loading
conditions. Its relatively low cost makes it attractive
for upgrading an overloaded plant.
Although the use of influent sewers for
equalization should not be ignored, the most
positive and effective means to maximize the
benefits possible with equalization is through the
use of specially designed equalization basins. These
basins should normally be located near the head end
of the treatment works, preferably downstream of
pretreatment facilities and mixing must be provided
to keep the basins aerobic and prevent solids
deposition.
It is sometimes desirable to locate the
equalization basin at strategic locations within the
collection system. This offers the added advantage
of economically relieving trunk sewer overload
during peak flow periods.1 However, it does result in
the need for a pumping facility and therefore is best
located where a need for pumping already exists.
Equalization basins may be desired as either
in-line or side-line units. In the in-line design all the
flow passes through the equalization basin. This
results in significant concentration and mass flow
damping. In the side-line design only that amount of
flow above the daily average is diverted through the
equalization basin. This scheme minimizes pumping
requirements at the expense of less effective
concentration damping.
For new construction and for upgrading large
plants, it is desirable to construct compartmental-
ized or multiple basins. This feature will allow the
flexibility to dewater a portion of the facility for
maintenance or equipment repair while still
providing some flow equalization. Where a basin is
designed for storage and equalization of wet
weather flows, compartmentalized tanks will allow
the utilization of a portion of the basin for dry
weather flow equalization.
Single basin installations may be used for
upgrading small plants, but must have the provision
to be dewatered while maintaining complete
treatment. This will require a bypass line around the
basin to allow the downstream portion of the plant
to operate unequalized when the flow equalization
facility is out of service.
Impact On Primary Settling
The most beneficial impact on primary settling is
the reduction of peak, overflow rates resulting in
improved performance and a more uniform primary
effluent quality. Flow equalization permits the sizing
of hew clarifiers based on equalized flow rates
rather than peak rates. In an existing primary
clarifier that is hydraulically overloaded during
periods of peak diurnal flow, equalization can reduce
the maximum overflow rate to an acceptable level. A
constant influent feed rate also avoids hydraulic
disruptions in the clarifier created by sudden flow
changes, especially those caused by additional
wastewater lift pumps suddenly coming on line.
LaGregaand Keenan2 investigated the effect of
flow equalization at the 1.8 mgd Newark, N.J.,
Wastewater Treatment Plant. An existing aeration
tank was temporarily converted to an equalization
basin. They compared the performance of primary
settling under marginal operating conditions, with
and without equalization. The results are show in
Table 1.
It has been demonstrated3,4 that preaeration can
significantly improve primary settling. Roe3
concluded that preaeration perflocculates sus-
pended solids (SS) thereby improving their settling
characteristics. Indications are that this benefit may
be realized by aerated equalization basins. This
benefit may be diminished when the equalized flow
is centrifugally pumped to the primary clarifier due
to the shearing of the floe.
Impact On Biological Treatment
Table - Effect if flew equalization on pritnaty settlini, Newatk, H.I.
Item
Normal flow
Equalized flow
Primary influent SS, mg/l	
136.7
128
Primary effluent SS, mg/l	
105.4
68
SS removal in primaries, percent	
23
47
Note.- Average flow slightly higher in unequalized portion of study.
As contrasted to primary treatment or other
mainly physical processes where concentration
damping is of minor benefit, biological treatment
performance can benefit significantly from both
concentration damping and flow smoothing.
Concentration damping can protect biological
processes from upset or failure from shock loading
of toxic or treatment inhibiting side-line basins for
biological treatment applications.
Improvement effluent quality due to stabilized
mass loading of BOD on biological systems treating
normal domestic wastes has not been adequately
demonstrated to date. It is expected that the effect
will be significant where diurnal fluctuations in
organic mass loadings are extreme. This situation
may arise at a wastewater treatment plant receiving
a high-strength industrial flow of short duration.
Damping of flow and mass loading will also improve
aeration tank performance where aeration
equipment is marginal or inadequate in satisfying
peak diurnal-loading oxygen demands.5
The optimum pH for bacterial growth lies between
6.5 and 7.5. In-line flow equalization can provide an
effective means for maintaining a stabilized pH
within this range.
Flow smoothing can be expected to improve final
settling even more so than primary settling. In the
activated-sludge process, flow equalization has the
added benefit of stabilizing the solids loading on the
final clarifier. This has two ramifications:
• The mixed-liquor suspended solids (MLSS)
concentration can be incareased thereby
decreasing the food-to-mass ratio (F/M) and
increasing the solids retention time (SRT). This
may result in an increased level of nitrification,
and a decrease in biological sludge production. It
may also improve the performance of a system

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operating at an excessively high daily peak F/M.
•Diurnal fluctuations in the sludge blanket level
will be reduced. This reduces the potential for
solids being drawn over the weir by the higher
velocities in the zone of the effluent weirs.
Miscellaneous Benefits
In chemical coagulation and precipitation systems
using iron aluminum salts, the quantity of chemical
coagulant required as proportional to the mass of
material to be precipitated. Damping of mass
loadings with in-line equalization will improve
chemical feed control and process reliability, and
many reduce instrumentation complexity and costs.
Flow smoothing will reduce the surface area
required and enhance the performance of tertiary
filters. A constant feed rate will lead to more uniform
solids loadings and filtration cycles.
The equalization basin provides an excellent point
of return for recycled concentrated waste streams
such as digester supernatent, sludge-dewatering
filtrated, and polishing-filter backwash.
Some biochemical oxygen demand (BOD)
reduction is likely to occur in an aerated
equalization basin. A 10-to-20-percent reduction
has been suggested for an in-line basin equalizing
raw wastewater. However, the degree of reduction
will depend upon the detention time in the basin, the
aeration provided, wastewater temperature, and
other factors. For an existing treatment plant, a
simple series of oxygen uptake studies on a
representative sample of wastewater can determine
the BOD reduction that will occur.
Roe3 observed that preaeration may improve the
treatability of raw wastewater by creating a positive
oxidation-reduction potential, thereby reducing the
degree of oxidation required in subsequent stages of
treatment.
Determination Of Equalization Requirements
The design of an equalization basin requires the
evaluation and selections of a number of features as
follows:
•	In-line versus side-line basins
•Basin volume
•	Degree of compartmentalization
•	Type of construction-earthen, concrete, or steel
•	Aeration and mixing equipment
•	Pumping and control concept
•	Location in treatment system
The design decisions must be based on the nature
and extent of the treatment processes used, the
benefits desired, and local site conditions and
constraints.
It rhay not be necessary to equalize the entire
influent flow where high flow or concentration
variations can be attributed to one source, such as
an industry. In these cases the desired benefits can
be achieved by simply equalizing the industrial flow.
This can be accomplished through construction of
an equalization basin at the industrial site or
through in-house industrial process modifications to
effect and equalized wastewater discharge.
Determination Of Required Volume
BOD mMi load

Fisure 1. Raw Wastewater How and BOD variation before equalization
Two methods are available for computing
equalization volume requirements. One procedure
is based on the characteristic diurnal flow pattern.
In this case, the function of the basin is to store flows
in excess of the average daily flow and to discharge
them at times when the flow is less than the
average. The required volume can be determined
graphically through the construction of a
hydrograph. The second procedure is based upon
the mass loading pattern of a particular constituent.
This method computes the volume required to
dampen mass loading variations to within a preset
acceptable range6'7
Since the prime objective of flow equalization in
wastewater treatment is to equalize flow, the
determination of equalization volume should be
based on the hydrograph. Once the volume has been
determined for flow smoothing, the effect on
concentration and mass load damping can be
estimated. The required volumes for side-line and
in-line basins will be identical. The hydrograph
procedure is discussed below.
The first step in design involves the establishment
of a diurnal flow pattern. Whenever possible, this
should be based upon actual plant data. It is
important to note that the diurnal pattern will vary
from day to day, especially from weekday to
weekend, and also from month to month. The
pattern selected must yield a large enough basin
design to effectively equalize any reasonable dry
weather diurnal flow. Figure 1 depicts a typical
diurnal flow pattern. The average flow rate is 4.3
mgd. For purpose of this example, the average flow
is used as the desired flow rate out of the
equalization basin. The diurnal peak and minimum
flow rate for this example are 1.7 and 0.45 times the
average, respectively.
The next step involves the actual construction of
the hydrograph. The hydrograph for this example is
shown on figure 2. The inflow mass diagram is
plotted first. To do this, the hourly diurnal flows are
converted to equivalent hourly volumes, and
accumulated over the 24-hour day. A line is then
drawn from the origin to the end point on the
inflow-mass diagram. The slope of this line actually
represents the average flow for the day.
Enough tank volume must be provided to
accumulate flows above the equalized flow rate. This
normally requires a volume equivalent to 10 to 20
percent of the average daily dry weather to the

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average flow are shown as lines A and B on figure 2.
The required volume is represented by the vertical
distance between these two lines. In this illustration,
the required volume for equalization is 740,000
gallons, which represents approximately 17 percent
of the average daily flow.
Fifuri 2. Hytfrograph for typical diurnal flow.
The actual equalization-basin volume must be
greater than that obtained with the hydrograph for
several reasons, including
Continuous operation of aeration and mixing
equipment will not allow complete drawdown.
•	Volume must be provided to accommodate
anticipated concentrated plant recycle streams.
•	Some contingency should be provided for
unforeseen changes in diurnal flow.
The final volume selected should include adequate
consideration of the conditions listed above and will
also depend on the basin geometry. For the example
presented herein, a basin volume of approximately 1
million gallons is adequate.
References
JC. N. Click, "The Feasibility of Flow Smoothing
Stations in Municipal Sewage System," USEPA
Project No. 11010FDI, Contract No. 14-12-935, Aug.
1972.
2M. D. LaGrega and J. D. Keenan, "Effects of
Equalizing Sewage Flow," presented at 45th Annual
Conference of the Water Pollution Control
Federation, Atlanta, Ga., Oct. 1972.
3F. C. Roe, "Preaeration and Air Flocculation,"
Sewage Works J., 23, No. 2. 127-140, 1951.
4H. F. Seifel and E. R. Baumann, "Effect of
Preaeration on the Primary Treatment of Sewage,:
J. Water Pollut. Cont. Fed., 33 No. 4, 339-355, 1961.
5A. G. Boon and D. R. Burgess, "Effects of Diurnal
Variations in Flow of Settled Sewage on the
Performance of High Rate Activated-Sludge Plants,"
Water Pollution Cont., 493-522, 1972.
6 P. R. Bradley and J. Y. Oldshue, "The Role of
Mixing in Equalization," presented at 45th Annual
Conference of the Water Pollution Control
Federation, Atlanta, Ga., Oct. 1972.
7A. T. Wallace, "Analysis of Equalization Basins,"
J. Sanit. Eng. Div., ASCE, SA6, 1161-1171, 1968.
Where To Get Further Information
In order to get details on items appearing in this publication, or any other aspects
of the Technology Transfer Program, contact your EPA Regional Technology Trans*
fer Committee Chairman from the list below:
REGION CHAIRMAN
i Letter Sutton
II Robert Olson
Ml Albert Montague
IV Au B. Foster, Jr.
V Clifford Risloy
ADDRESS
Environmental Protection Agency
John F. Kennedy Federal Building
Room 2304
Boston, Massachusetts 02203
617 223-2226
[Maine, N.H., Vt„ Mass, R.I., Conn.]
Environmental Protection Agency
26 Federal Plaza
New York, New York 10017
212 264*1867
IN.V„ N.J, P.R., V.I.)
Environmental Protection Agency
6th & Walnut Streets
Philadelphia, Pennsylvania 19106
215 597-9896
[P»„ W.Va, Md, Dei- D.C„ Va.)
Environmental Protection Agency
Suite 300
1421 Peechtree Street, N.E.
Atlanta, Georgia 30309
404 526*3454
(N.C„ S.C, Ky„ Tenn, Gan Ma., Mill, Fta.]
Environmental Protection Agency
1 N. Wacker Drive
Chicago, Illinois 60606
312 353-5756
[Mich., Wit, Minn., III., Ind- Ohio]
REGION CHAIRMAN
VI Mildred Smith
VII John Coakley
VIII Russell Fitch
IX Frank Covington
X John Osbom
ADDRESS
Environmental Protection Agency
1600 Patterson Street Suite 1100
Dallas. Texas 75201
214 749-1461
[Texas, Okla., ArH„ u., N. Me*.]
Environmental Protection Agency
1735 Baltimore Avenue
Kansas City, Missouri 64108
816 374-5971
[Kansas, Nebr, Iowa, Mo.]
Environmental Protection Agency
1860 Lincoln Street
Denver, Colorado 80203
303 837-3849—-837*3691
(Coku Mont, Wyo- Utah, NJ>, S.D.]
Environmental Protection Agency
100 CatHomla Street
San Francisco, Calif. 94111
415 556-0218
[Calif. Arte, Nov, Hawaii]
Environmental Protection Agency
1200 6th Avenue
Seattle. Washbtfon 98101
206 442*1296
[Wash, Ore, Idaho, Alaska]

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REQUEST FOR TECHNOLOGY TRANSFER MATERIAL
Please send me the following publications at no charge. (Check appropriate boxes) The publications Listed on this form are the only ones
available through the Office of Technology Transfer.
PROCESS DESIGN MANUALS
~	Phosphorus Removal	1001
~	Carbon Adsorption		1002
~	Suspended Solids Removal	1003
G Upgrading Existing Wastewater
Treatment Plants	1004
~	Sulfide Control in Sanitary
Sewerage Systems	1005
* Q Sludge Treatment
and Disposal 	1006
MUNICIPAL SEMINAR PUBLICATIONS
~ Upgrading Lagoons	4001
G Physical-Chemical Treatment 	4002
0 Oxygen Activated Sludge	4003
G Nitrification/Oenitrification 	4004
G Upgrading Existing Wastewater
Treatment Facilities-Case Histories	4005
•	G Flow Equalization 	4006
•	G Wastewater Filtration	4007
•	G Physical-Chemical Nitrogen Removal	4008
TECHNICAL CAPSULE REPORTS
G Recycling Zinc in Viscose Rayon
Plants	2001
G Color Removal from Kraft Pulping
Effluent by Lime Addition	2002
G Pollution Abatement in a Copper
Wire Mill 	2003
G First Interim Report on EPA Alkali SO2
Scrubbing Test Facility	2004
G Dry Caustic Peeling of Peaches	2005
• G Pollution Abatement in a
Brewing Facility 	2006
BROCHURES
G Physical-Chemical Treatment	5001
G Phosphorus Removal	5002
G Upgrading Existing Wastewater
Treatment Plants	5003
G Carbon Adsorption	5004
G Oxygen Aeration	5005
G Nitrogen Control	5006
G Seattle, Washington METRO	5007
G Wastewater Purification at Lake Tahoa	5008
G Indian Creek Reservoir	5009
G Richardson, Texas 	5010
INDUSTRIAL SEMINAR PUBLICATIONS
G Upgrading Poultry Processing Facilities
to Reduce Pollution (3 Vols.)	3001
G Upgrading Metal Finishing Facilities
to Reduce Pollution (2 Vols.)	3002
G Upgrading Meat Packing Facilities
to Reduce Pollution (3 Vols.)	3003
» G Upgrading Textile Operations
to Reduce Pollution (2 Vols.)	3004
HANDBOOKS
G Analytical Quality Control In Water -
and Wastewater Laboratories	6001
G Monitoring Industrial Wastewater	6002
* Publications listed for first time
For the following audio-visual material, please contact your Regional Technology Transfer Chairman. (See listing)
MOTION PICTURES (16mm sound)	VIDEOTAPES
Richardson Texas Project - Title:	Carbon Adsorption (40 min.)
"Somebody around here must be doing something good." (15 min.)
Upgrading Activated Sludge
Phosphorus Removal (5 min.)	Treatment Plants (40 min.)
Water Quality Management, Alameda Creek, Calif. - Title:
"The Water Plan" (28K min.)
The Seattle METRO Story (28 min.)
If you are not currently on the mailing list for this Technology Transfer Newsletter, do you want to be added? GyES GnO
Name				
Employer			Title		
Street	 Phone	
City			State		 Zip.
NOTE: Tear this sheet out and forward to Technology Transfer, U.S. Environmental Protection Agency, Washington, D.C. 20400.

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