National Seminar on
Flow Techn
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S. Kairr
Environmental Research Laboratory
Office of Wffler Programs
Center for Imvironrngnta!
Reseamh
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NATIONAL SEMINAR ON OVERLAND FLOW
TECHNOLOGY FOR
MUNICIPAL WASTEWATER
September 16, 17 and 18, 1980
SEMINAR SPONSORS
Dr. Curtis Harlin
Robert S. Kerr Environmental Research Lab
Mr. Dick Thomas
EPA Construction Grants Program
For Further Seminar Information Contact:
Enviro Control, Inc.
One Centrrl Plaza
11300 Rockville Pike
Rockville, MD 20852
(301)468-2500
SEMINAR COORDINATORS
Sheri E. Marshall
Gail E. Cioban
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Table of Contents
AGENDA 1
ABSTRACTS
EPA Policy and Guidance on Overland Flow 6
Richard E. Thomas
Policy and Guidelines , . 7
Jon C. Dyer
Developmental Research for Overland Flow Technology 8
Bert E. Bledsoe
Overland Flow Treatment of Municipal Lagoon Effluent 9
C. R. Lee and R. E. Peters
Municipal Wastewater Treatment by Overland Flow at Pauls
Valley, Oklahoma . 10
Charles H. Lawrence
Development of'a' Rational Basis for the Design and Operation
of the Overland Flow Process 11
Robert G. Smith
The Easley, South Carolina Overland Flow Project 12
A. Ray Abernathy
Remove! of Organics by Overland Flow 13
C. James Martel
Health Aspects - Overland Flow Systems 14
Osman M. Aly
Nitrogen and Phosphorus Removal Processes in Overland Flow
Treatment Systems for Municipal Wastewater 15
William H. Patrick, Jr., and Rashid A. Khalid
Effects of Suspended Solids on Overland Flow Design and
Operation ^-. ... 16
Lloyd H. Ketchum, Jr.
Overland Flow Treatment: A Case History at Shafter,
California 17
Charles E. Pound and Richard W. Corneille
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Table of Contents
Case History - Kenbridge, Virginia 18
D. Donald Deemer
Overland Flow System: Vinton, Louisiana-Case Study 19
Kelly M. Peil
Overland Flow System Application at Heavener, Oklahoma,
for Treatment of Domestic Wastewater 20
Jimmie M. Alford
Design Example for Overland Flow 21
D. Donald Deemer
INDEX 22
NOTES
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Agenda
TUESDAY, SEPTEMBER 16, 1980
8:00 a.m. REGISTRATION
SESSION I
Introduction and Overview
9:00 a.m. WELCOMING ADDRESS
Mr. Myron 0. Knudson
Director of Water Division
Region VI
Dallas, TX
> ^
9:15 a.m. OVERVIEW
Dr. Curtis Harlin
Robert S. Kerr Environmental Research Lab
Ada, OK
9:30 a.m. POLICY AND GUIDANCE - FEDERAL SUMMARY
Mr. Dick Thomas
EPA Construction Grants Program
Washington, DC
10:00 a.m. COFFEE BREAK
10:30 a.m. POLICY AND GUIDANCE - STATE SUMMARY
Mr. Jon Dyer
Environmental Technology Consultants, Inc.
Springfield, VA
11:00 a.m. PANEL DISCUSSION WITH STATE AGENCY REPRESENTATIVES
12:00 Noon LUNCH
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Agenda
TUESDAY (continued)
SESSION 2
Research and Development
Moderator - Mr. Ancil A. Jones
EPA Region VI
Dallas, TX
1:30 p.m. ADA3 OK
Mr. Bert E. Bledsoe
Robert S. Kerr Environmental Research Lab
Ada, OK
2:00 p.m. UTICA, MS
Mr. Robert E. Peters
Waterways .Experiment Station
Vicksburg, MS
2:30 p.m. PAULS VALLEY, OK
Dr. Charles H. Lawrence
University of Oklahoma, Health Sciences Center
Oklahoma City, OK
3:00 p.m. COFFEE BREAK
3:30 p.m. DAVIS3 CA
Dr. Robert G. Smith.,.
University of California
Davis, CA
4:00 p.m. EASLE1'3 SC
Dr. A. Ray Abernathy
Clemson University
Clemson, SC
4:30 p.m. DISCUSSION
5:00 p.m. RECESS
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Agenda
WEDNESDAY, SEPTEMBER 17, 1980
SESSION 3
Process/Removal Mechanisms
Moderator - Mr. Richard Duty
Robert S. Kerr Environmental Research Lab
Ada, OK
9:00 a.m. INTRODUCTION
Mr. Richard Duty
9:30 a.m. ORGANICS
Mr. John Bouzoun
"U.S. Army Cold Regions Research and Engineering Lab
Hanover, NH
10:00 a.m. HEALTH ASPECTS
Dr. 0. M. Aly
Technological Resources, Inc.
Camden, NJ
10:30 a.m. COFFEE BREAK
11:00 a.m. NUTRIENTS
Dr. William H. Patrick, Jr.
Louisiana State University
Baton Rouge, LA
11:30 a.m. SUSPENDED SOLIDS
Dr. Lloyd Ketchum, Jr.
University of Notre Dame
Notre Dame, IN
12:00 Noon LUNCH
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Agenda
WEDNESDAY, (continued)
SESSION 4
Case Histories
Moderator - Mr'. Dick Thomas
1:30 p.m. SHAFTER, CA
Mr. Richard W. Corneille
Metcalf & Eddy, Inc.
San Bernardino, CA
2:00 p.m. KENBRIDGE, VA
Mr. Donald Deemer
Technological Resources, Inc.
Camden, NJ
2:30 p.m. DISCUSSION
3:00 p.m. COFFEE BREAK
3:30 p.m. VINTON, LA
Dr. Kelly Peil
Roy F. Weston, Inc.
Houston, TX
4:00 p.m. HEAVENER, OK
Mr. Jimmie M. Alford
Alford Engineering Company
Hot Springs, AR
4:30 p.m. DISCUSSION
5:00 p.m. RECESS
5:30 p.m. SOCIAL HOUR - Cash Bar
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Agenda
THURSDAY, SEPTEMBER 18, 1980
SESSION 5
Design
Moderator - Mr. Dick Thomas
9:00 a.m. DESIGN EXAMPLE
Mr. Donald Deemer
10:30 a.m. COFFEE BREAK
11:00 a.m. SUMMARY AND CLOSING REMARKS
Dr. Curtis Harlin
Mr. Dick Thomas
12:00 Noon ADJOURN
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Abstracts
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EPA POLICY AND GUIDANCE ON OVERLAND FLOW
Richard E. Thomas, Municipal Construction Division
U.S. Environmental Protection Agency
Overland flow is a developing alternative technology in the context of
policies, regulations, and guidance for the Federal Construction Grants Pro-
gram administered by the Environmental Protection Agency (EPA). Its use is
encouraged in the policy statement issued in October 1977, placing strong
emphasis on the need to give full consideration to land treatment during the
planning of facilities receiving construction grant funding.
Consideration of overland flow in facility planning presents specific
and rather unique circumstances because it is a developing technology and
there is limited operational experience. The EPA has adopted a position of
flexibility for case-by-case determinations and recognizes that most overland
flow projects meet the criteria for being designated as innovative. This
approach fosters the adoption of innovative and alternative technology con-
currently with development of expertise and guidance at the State and local
levels. EPA has issued general guidance on preapplication treatment and
system designs as it becomes available. The Agency will continue to provide
additional technical information as it becomes available. The Agency will
also provide technical assistance on the planning and design of specific
projects until there is sufficient operational experience to provide a firm
basis for routine use of overland flow technology.
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POLICY AND GUIDELINES - STATE SUMMARY
Jon C. Dyer, President
Environmental Technology Consultants, Inc.
Land treatment of municipal wastewater is a reliable and proven
technology that has come back into serious consideration in recent years.
Although most states have regulations and guidelines addressing land
treatment, overland flow technology is mentioned in only sixteen. However,
some of these sixteen states have only draft regulations and guidelines that
are not yet adopted as law (although they are used by the state agencies).
Overland flow technology is being recognized for the first time
in many of these states. -There is a positive correlation between states
that have existing or planned overland flow systems and those that have
regulations and guidelines. Many states appear unaware of, unconcerned for,
or misinformed about overland flow technology as a viable and potentially
cost-effective wastewater treatment alternative.
Political and geographic differences strongly influence each state's
position. Soil type is the most important geographic influence while water
rights considerations are the most important political problem. The states
that recognize overland flow as a viable alternative generally have set
forth guidelines addressing buffer zones, slopes, pretreatment, site
conditions, etc.
Public health and protection of surface waters are of major concern.
A comparison of state requirements and technical concerns reveals the dif-
ferent emphasis in state policy. Many state regulations need to be revised
in light of utilizing this alternative technology. Use of overland flow
technology can be beneficial to local and state pollution control
strategies.
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DEVELOPMENTAL RESEARCH FOR OVERLAND FLOW TECHNOLOGY
Bert E. Bledsoe, Research Chemist
Robert S. Kerr Environmental Research Laboratory, U.S. Environmental
Protection Agency
A chronological description of overland flow development technology
conducted by the Robert S. Kerr Environmental Research Laboratory is
presented. The data accumulated are from pilot-scale field activities. Raw,
primary, and secondary domestic wastewaters have been applied. A brief review
of published data is reported but emphasis is on the most recently acquired
data.
The initial study demonstrated the feasibility of treating raw domestic
wa'stewater by overland flow. The removal efficiencies were determined for
most classical wastewater parameters with varying hydraulic loading. The
relatively low phosphorus removal was the basis for a continuation study for
enhanced phosphorus removal by chemical addition of aluminum sulfate. The
pretreatment studies include three levels of preapplication treatment and two
loading rates for both primary and secondary treated wastewaters.
Cumulative relative frequency distribution plots of effluent concen-
trations for total suspended solids, total organic carbon, total phosphorus,
ammoniacal, nitrate, and total Kjeldahl nitrogen are discussed for the
different application rates and degrees of pretreatment. Nutrient removal
with respect to horizontal distance or contact time is presented for varying
hydraulic loading and preapplication treatment. Data presented will support
the hypothesis of biochemical transformations of nitrogen with nitrification
in the upper and denitrification in the lower portions of the treatment plots.
The following additional topics will be discussed: the nitrate flush from
initial start of application cycle; seasonal variation of selected parameters;
effect of rainfall during application and drying cycles; and preliminary
data on the effect of application cycle with a constant hydraulic load.
8
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OVERLAND FLOW TREATMENT OF MUNICIPAL LAGOON EFFLUENT
C. R. Lee, Soil Scientist
R. E. Peters, Agricultural Engineer
Environmental Laboratory, U. S. Army Engineer Waterways Experiment Station
Overland flow treatment of a municipal lagoon effluent has been studied
for four years at Utica, Mississippi. A research facility was established in
1975 under the joint sponsorship of the U. S. Army Corps of Engineers and the
U. S. Environmental Protection Agency. The facility consists of 24 research
plots, 8 plots each on slopes of 2, 4, and 8%. Each plot is 4.5 m wide with a
slope length of 45 m. The experimental layout enabled duplication of four
different modes of operation on each slope for a comprehensive evaluation of
overland flow treatment of wastewater.
Factors evaluated were wastewater application rate (0.071 to 0.847 cm/hr),
period (6, 18, 24 hr), and frequency (5 or 7 days/week); slope; Crop manage-
ment; removal efficiency of biochemical oxygen demand, suspended solids,
algae, nitrogen, phosphorus, heavy metals, and coliforms; and effects of
storm events. Results of three years of data collection will be discussed.
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MUNICIPAL WASTEWATER TREATMENT BY OVERLAND FLOW AT PAULS VALLEY, OKLAHOMA
Charles H. Lawrence, Professor
University of Oklahoma Health Sciences Center
Department of Environmental Health
This study assessed, on a seasonal basis, (a) the treatment of raw muni-
cipal wastewater by rotating boom, fixed riser, and trough methods of appli-
cation on overland flow modules constructed on 2 and 3 percent slopes, (b)
the treatment of wastewater stabilization pond effluent utilizing the fixed
riser and trough methods of application also on plots having 2 and 3 percent
slopes, and (c) the treatment achieved by overland flow compared to a waste-
water stabilization pond receiving the same wastewater.
The research protocol also involved the determination and comparison of
(a) the bacterial and viral components of the wastewater before and after
application to the overland flow plots, (b) the airborne bacteria upwind and
downwind of the rotating boom applicators, and (c) the composition of the.
soil before and after wastewater application.
The raw overland flow treatment system achieved, under summer and winter
operation, BOD and suspended solids levels comparable to those of mechanical
secondary treatment; however, fecal coliform analyses indicated reductions
of less than one order of magnitude. No meaningful phosphorus reductions
were observed especially during the summer when most plots produced increases
in effluent phosphorus concentrations. The nitrogen balance indicated
organic nitrogen reductions of approximately 50 percent for both seasons with
ammonia removals being about the same for the winter but somewhat higher for
the summer. No appreciable changes in nitrate concentrations were observed.
Of those tested, no single method of application, slope,, or combination
thereof was found to be consistently superior.
The viral assay revealed that the plots were able to effect 100 percent
reductions except during peak summer loadings. Airborne bacteria were
isolated in significantly greater quantities downwind of the rotating boom;
however, no airborne viruses were isolated from the same locations.
The limited soil analyses conducted indicated an increase in calcium and
copper and a decrease in phosphate and potassium in the surface soil samples.
Overland flow provided only limited benefits for the treatment of waste-
water stabilization effluent. Neither overland flow nor the wastewater
stabilization pond demonstrated a superior overall performance for the
treatment of raw domestic wastewater.
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DEVELOPMENT OF A RATIONAL BASIS FOR THE DESIGN AND OPERATION OF THE OVERLAND
FLOW PROCESS
Robert G. Smith, Associate Development Engineer
Department of Civil Engineering, University of California, Davis
The Department of Civil Engineering at the University of California at
Davis is conducting an overland flow research project under the sponsorship
of the State of California Water Resources Control Board. The principal
objectives of the research are to define the design and operating parameters
that govern the treatment performance of the overland flow process and to
develop a functional relationship between the governing parameters and treat-
ment performance that can be used as a rational basis for design and operation
of the overland flow systems.
The project is being conducted in two phases. Phase I involves pilot
studies conducted indoors, using three 6 by 1.5-m overland flow beds. Phase
II involves full-scale field studies conducted at a 9.3-hectare facility that
is part of a 73-he.ctare overland flow facility operated by the city of Davis.
Phase I pilot studies have been completed. Phase II facilities are under
construction and research is scheduled to begin in the fall of 1980.
The principal findings from Phase I are:
1. Removal efficiency (E) of organic material from municipal primary
effluent by overland flow is:
a. independent of slope grade in the range of 2 to 6 percent;
b. independent of hydraulic loading rate in the range of 2 to 11.7
cm/day, based on 30 m of slope length;
c. governed only by the application rate per unit width of slope (q)
and the slope length (z) and can be described as a function of
these two parameters by a predictive model of the following form:
E = [1 - A exp (- ^)] 100
qn
where A, K, and n are empirical coefficients.
2. The predictive model described above can be used as a rational basis for
computing the total area required for an overland flow system that will
achieve a specified organic removal efficiency.
3. Continuous application of.primary effluent for a period of 3 weeks does
not affect organic removal efficiency, but damage to the cover crop at
the top of the slope begins^to occur due to solids deposition.
11
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THE EASLEY, SOUTH CAROLINA OVERLAND FLOW PROJECT
A. Ray Abernathy, Professor of Environmental Systems Engineering
Environmental Systems Engineering Dept., Clemson University
An overland flow treatment facility has been designed and constructed
at Easley, South Carolina, to treat 75,000 gpd of oxidation pond effluent
and 25,000 gpd of raw domestic sewage. Separate pumping and distribution
systems were installed for each wastewater, and multiple plots were con-
structed so that various combinations of wastewater flow rate and waste-
water application frequency could be studied. The system has been in
operation for 18 months.
Removals of BOD_, organic carbon, suspended solids, and compounds of
nitrogen and phosphorus were measured as functions of flow rate and ap-
plication schedule. Hydraulic recovery was measured to allow computation
of removals on a mass flow rate basis. Samples were collected at intervals
down the plots in order to relate removals to the distance of movement over
the plot.
Results indicate that effluent quality for both types of wastewater is
comparable to conventional activated sludge systems with respect to BOD,.
and suspended solids. Removals of compounds of nitrogen and phosphorus
have been greater than would be expected from conventional sewage treat-
ment systems. Hydraulic recoveries have been variable, depending on season,
climatic conditions, and antecedent precipitation. On a mass flow rate
basis the removals observed have been significantly greater than those of
typical secondary treatment systems.
Limited data on viable microbial aerosols and ground water quality in
test wells fail to show evidence of serious environmental degradation.
There have been no problems with foul odors or public complaints.
12
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REMOVAL OF ORGANICS BY OVERLAND FLOW
C. James Martel, Environmental Engineer
U.S. Army Cold Regions Research and Engineering Laboratory
Many studies have shown that overland flow systems can effectively re-
move organics from municipal wastewater. Typically, runoff concentrations
of BOD are 10 mg/1 or less. The mechanisms responsible for organic removal
are sedimentation, filtration and biochemical oxidation. Sedimentation and
filtration remove the particulate fraction and biochemical oxidation re-
moves the soluble fraction.
Studies conducted at the U.S. Army Cold Regions Research and Engineering
Laboratory (USACRREL) indicated that removal of BOD can be described by a
first-order equation. The reaction rate constant for this equation was
0.03 min.~l An average detention time of 60 minutes was needed to attain
90% BOD removal.
Trace qrg'anic removal can also be described by first-order kinetics.
The reaction rate constants were higher for trace organics removal than BOD
removal. For example, chloroform had an average rate constant of 0.053
min."-*- Volatilization appears to be the primary mechanism responsible for
removal.
An empirical equation was developed at USACRREL which relates applica-
tion rate to detention time and overland flow site characteristics. This
equation was validated using data from the Utica Ms. and the University of
California at Davis overland flow systems. The average difference between
measured and predicted detention time values was found not significant at
the 95% level. This equation can be used in design to predict the applica-
tion rate needed to achieve the desired degree of organic removal.
13
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HEALTH ASPECTS - OVERLAND FLOW SYSTEMS
Osman M. Aly, Director-Technical Services
Technological Resources, Inc.
The major public health concerns that usually arise,in connection with
land treatment of municipal wastewaters include the potential of occupational
or environmental exposure to microbial pathogens, biological or chemical
contamination of groundwater supplies, or contamination of food crops or
livestock feed. Because of the nature of overland flow treatment systems,
many of these health risks are minimized or completely eliminated.
Overland flow systems are designed for soils rich in clay content with
low permeability or soils with impermeable barriers and, therefore, the
potential of groundwater contamination is very limited or almost improbable.
Because of the high hydraulic application rates, these systems are not
suitable for the production of food crops for human consumption and,
therefore, this health risk factor is nonexistent. Overland flow systems
are also designed for the biological treatment of wastewater as it flows
over the soil surface and a final discharge of the treated effluent to a
receiving water body is required. Therefore, the relative health risks
associated with these systems should be evaluated against the same
yardsticks or criteria applied to other conventional biological treatment
systems.
An overview of the processes and mechanisms involved in the removal
of microbial and chemical contamination in overland flow systems is
presented together with a discussion of mitigation measures that can be
taken for minimizing potential health risks.
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NITROGEN AND PHOSPHORUS REMOVAL' PROCESSES IN OVERLAND FLOW TREATMENT SYSTEMS
FOR MUNICIPAL WASTEWATER
William H. Patrick, Jr., Boyd Professor
Rashid A. Khalid, Associate Professor
Laboratory for Wetland Soils and Sediments, Center for Wetland Resources
Louisiana State University, Baton Rouge, LA 70803
Most municipal wastewaters contain significant concentrations of
nutrients, primarily nitrogen and phosphorus, and can be serious pollutants if
discharged to surface waters. Research studies conducted in the United States
and elsewhere in the past decade indicate overland flow to be an effective
treatment system for removal of nitrogen from municipal wastewater while phos-
phorus removal efficiency has been found to vary over a wide range. The
nutrients' removal efficiency in the overland flow system is influenced by
physical, chemical, biological and environmental factors which must be care-
fully considered in designing a treatment facility. This presentation will
focus on the mechanisms of various nitrogen and phosphorus removal processes
during overland flow application of wastewater and the factors that limit
these processes.
Nitrogen removal is attributed to gaseous nitrogen losses through deni-
trification reactions, plant uptake by the established vegetation, and under
alkaline conditions, to ammonia volatilization losses. The results of studies
conducted in this laboratory and elsewhere suggest that the gaseous loss of
applied nitrogen can be maximized during overland flow application of waste-
water containing ammonium nitrogen if conditions favorable for simultaneous
nitrification-denitrification reactions are attained. Some of the important
factors that control these reactions are redox potential, pH, energy source,
and microbial populations. The contribution of various mechanisms involved in
the overall nitrogen removal is presented.
Phosphorus removal from the wastewater during overland treatment is
attained through sorption by the soil complex and uptake by the growing plants.
Extensive research has been conducted on the mechanisms and kinetics of phos-
phorus sorption which include adsorption and precipitation reactions. The
capacity of a soil to sorb phosphorus depends primarily on the concentration
of iron, aluminum, and calcium compounds in the soil which react with waste-
water phosphorus. However, a number of physicochemical parameters including
soil pH, redox potential and time of reaction significantly affect the equilib-
rium between solution- and solid-phase phosphorus and hence determine the
magnitude of phosphorus removed from wastewater. The role of these physico-
chemical parameters in enhancing phosphorus removal in the overland flow
treatment system is discussed in this presentation.
15
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EFFECTS OF SUSPENDED SOLIDS ON OVERLAND FLOW DESIGN AND OPERATION
Lloyd H. Ketchum, Jr., Associate Professor of Civil Engineering
University of Notre Dame
Biochemical Oxygen Demand (BOD) loadings, nutrient loadings and hydraulic
loadings usually have been used to establish design requirements for overland
flow treatment systems. Design considerations for suspended solids have
been limited to loadings the same as used for BOD, dealt with by allowing
greater hydraulic loadings if greater pretreatment was provided or more-or-
less have been ignored. Poor suspended solids reduction during operation
often resulted. Those periods of poor suspended solids reduction often have
been of short duration and with substantially higher effluent suspended
solids concentrations than ordinarily observed.
This paper summarizes operating experiences observed at a number of
sites and attempts to develop relationships between operating conditions
which resulted in poor suspended solids removal. Those comparisons from
site to site make some relationships more obvious than when limited to
single site observations. Based on those observations, modifications in
design approaches are recommended to improve effectiveness and consistency
of suspended solids reductions in overland flow treatment.
Some of the factors considered are effects of rainfall, effects of
pretreatment, types of soil, wastewater application techniques, and special
emphasis is given to algae in the effluent. Also, the origin of effluent
suspended solids is considered. The question which must be answered for
more effective design and operation is: are effluent suspended solids a
portion of the influent suspended solids, soil particles, grass fragments,
algae from the influent or generated on the plot, bacterial cell fragments,
or other particles generated on the plot?
16
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OVERLAND FLOW TREATMENT: A CASE HISTORY AT SHATTER, CALIFORNIA
Charles E. Pound, Vice President
Richard W. Corneille, Project Manager
Metcalf S Eddy, Inc.
An overland flow treatment system followed by irrigation of city-owned
crop lands is the recommended solution to wastewater management problems at
Shafter, California. This method of treatment was found to be the most cost
effective of the five other alternatives selected for competitive evaluation.
The facilities plan is still under review by the California State Water
Resources Control Board-and no immediate acceptance of the plan is expected.
The purpose of this paper is to present the preliminary design consider-
ations that went into the selection of the overland flow process as the best
apparent alternative. In addition, this paper is intended to illustrate the
difficulties that may be encountered in obtaining approval for an alternative
technology that is relatively new..and untried in the region. Two problem
areas may exist in gaining approval. First, the .governing board may be
reluctant to gamble with the community's funds on an unknown and untried area
of technology. Second, the reviewing or funding agency may be reluctant to
approve a plan which might cast a shadow on their record of project success.
Such problems support the need for Section 202 (a)(3) of Public Law 95-217
which is intended to guarantee results and assure regulatory authorities
that innovative and alternative technologies will not become "white elephants.
17
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CASE HISTORY - KENBRIDGE, VIRGINIA
D. Donald Deemer, Director-Project Development
Technological Resources, Inc.
The Town of Kenbridge, Virginia, is a small community with a
population of less than 2,000, located in the Piedmont region of south-
eastern Virginia, approximately 75 miles southwest of Richmond. In 1976,
a Step 1 Facilities Plan was developed for the town, the purpose of which
was to determine the most cost-effective method for improving the town's
wastewater treatment capabilities to conform with the proposed stream
discharge requirements.
The Facilities Plan recommended abandoning an existing wastewater
treatment system and building a new aerated lagoon system. However, due
to a combination of factors, the Facilities Plan had still not received
approval by the end of 1979. At this point, the community asked for
and received permission to develop an Addendum to the original Facilities
Plan to more fully evaluate the feasibility of utilizing some type of
land application process instead of the aerated lagoon system.
The additional land treatment evaluation determined that the overland
flow process was best suited for the available site conditions and that it
would be more cost-effective than the originally proposed alternative.
The next step, prior to applying for Step 2 funding, was to establish a
conceptual system design to satisfy the requirements of the Virginia State
Water Control Board and the Department of Health. Since the overland flow
process is not universally understood as yet and since there are no
existing overland flow projects in Virginia, this particular stage has
involved a great deal of discussion between the consultant and the
regulatory agencies.
18
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OVERLAND FLOW SYSTEM: VINTON, LOUISIANA CASE STUDY
Kelly M. Peil, Ph.D., P.E., Project Manager
Roy F. Weston, Inc.
The Town of Vinton, Louisiana, with a population of 4,000, is located
in the Southwest coastal section of the State. The Town outgrew their
20 year old trickling filter plant and entered the Construction Grants
Program in April 1977. The work completed to date includes: infiltra-
tion/inflow analysis, sewer system evaluation survey, specifications
for rehabilitation, environmental assessment and facility plan. The
selected treatment alternative was a 1.0 mgd overland flow system. The
land application system was compared to alternatives consisting of:
plant renovation and expansion, a new mechanical plant and a 3-cell
lagoon system.
The preliminary design of the system will be discussed. However,
since the treatment system is not in operation, this case study will
emphasize the Step One portion of the Construction Grants program and
transition from Step 1 to Steps 2 and 3. The Vinton project is one
of the early land application projects in the Region VI EPA and presenta-
tion of some of the problems in this project may assist others in
expediting their projects. Special emphasis will be made on the public
concern over the health effects and nuisance of a land application
system and the solution utilized to overcome these public concerns.
The current status of the project and the next steps will be presented
to conclude the case study.
19
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OVERLAND FLOW SYSTEM APPLICATION AT HEAVENER, OKLAHOMA,FOR'TREATMENT OF
DOMESTIC WASTEWATER
Jimmie M. Alford, Consulting Sanitary Engineer
Hot Springs, Arkansas (Associate Project Engineer)
A unique combination of geological, hydrological, and economic circum-
stances permitted overland flow to be a cost-effective treatment alternative
at Heavener, Oklahoma, a small community of 3,000 in southeast LeFlore County
in the Ouachita Foothills.
Water quality criteria for the receiving stream is no more stringent
than secondary treatment, but the municipal waste stream enters the Poteau
River above the source for the municipal water supply. Public concern was
generated, which caused a search for better-than-ordinary treatment pro-
cesses and more efficient removal mechanisms.
The efficiency of soil removal mechanisms toward toxic chemicals, in-
fectious biological agents, and other pollutant substances caused consider-
able interest in land application systems. Geological and hydrological con-
ditions prevented the use of low-rate and high-rate systems or total contain-
ment. The results of facilities planning indicate the need for 90 acre feet
of storage and up to 60 acres of application site. The proximity of a nat-
urally occurring site having ideal length, width, and cross slopes added to
the cost-effectiveness. Operational costs appear lower than other biological
and mechanical alternatives. The proposed system is ready for final detailed
design upon EPA approval of project documents.
Details are presented covering hydraulic and biological design criteria
for pretreatment processes and the overland flow system. Operational costs,
techniques, and control considerations are included.
20
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DESIGN EXAMPLE FOR OVERLAND FLOW
D. Donald Deemer, Director-Project Development
Technological Resources, Inc.
The design of an overland flow land treatment system requires an
interdisciplinary approach which involves knowledge of not only engineering
principles but also experience in the areas of soils, hydrogeology, and
agronomy. The purpose of this design example will be to outline a rational
approach to the design of an overland flow treatment system and to set
forth the various guidelines which should be followed during the design
stage.
The problem originates with a need for upgrading the wastewater
treatment facility for a small, rural community. An existing treatment
system is evaluated for use as preapplication treatment. Due to design
flows in excess of the existing plant capacity, the existing system
cannot be used and a new preapplication treatment system must be 'designed.
The design of the overland flow system begins with a review of the
stream discharge requirements and a preliminary investigation of the
potential land treatment site. This is generally sufficient to establish
whether the overland flow concept should be used. The next stage of the
design involves the determination of loading rates, storage, and land
area required. Having established this, the details of site development
can be resolved. Finally, the method and details of the wastewater
distribution system can be determined along with the type of cover crop
to be used and the types of monitoring systems required.
21
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Index
Abernathy, A. R 12
The Easley3 South Carolina Overland Flow .Project
Alford, J. M 20
Overland Flow System Application at Heavener, Oklahoma,
for Treatment '-of Domestic Wastewater
Aly, 0. M 14
Health Aspects - Overland Flow
Bledsoe, B. .E 8
Developmental Research for Overland Flow Technology
Corneille, R.-W 17
Overland'Flow Treatment: A Case History -at Shafter,
California
Deemer, D.D 18
Case History - Keribridge, Virginia
Deemer, D. D '. 21
Design Example for Overland Flow
Ketchum, L. H., Or 16
Effects of Suspended Solids on Overland Flow Design
and Operation
Khalid, R. A. 15
Nitrogen and Phosphorus Removal Processes in Overland Flow
Treatment Systems for. Municipal Wastewater
Lawrence, C. H 10
Municipal Wastewater Treatment by Overland Flow at Pauls
Valley, Oklahoma
22
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Index
Lee, C. R 9
Overland Flow Treatment of Municipal Lagoon Effluent
Martel, C.J 13
Removal of Organics by Overland Flow
Patrick, W. H 15
Nitrogen and Phosphorus Removal Processes in Overland Flow
Treatment Systems for Municipal Wastewater
Peil, K. M 19
Overland Flow System: Vinton} Louisiana
Peters, R. E 9
Overland Flow Treatment of Municipal Lagoon Effluent
Pound, C. E 17
Overland Flow Treatment: A Case Study at Shafter., California
Smith, R. G 11
Development of a Rational Basis for the Design and Operation
of the Overland Flow Process
Thomas, R.E 6
EPA Policy and Guidance on Overland Flow
23
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Notes
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National Seminar on
Overland Flow Technology for
Municipal Wastewater
Notes
-------
National Seminar on
Overland Flow Technology for
Municipal Wastewater
Notes
-------
National Seminar on
Overland Flow Technology for
.Municipal Wastewater
Notes
-------
National Seminar on
Overland Flow Technology for
Municipal Wastewater
Notes
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