EPA 600-9-79-009
IHjnicipal Environmental Research EPA-600/9-79-009
Laboratory April 1979
Cincinnati OH 45268
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United States Municipal Environmental Research
Environmental Protection Laboratory
Agency Cincinnati OH 45268
Research and Development
6ER& Report
of
Progress
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory and approved for publication. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
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FOREWORD
The chief aim and primary purpose of our laboratory is to develop technology,
systems, processes and improved management practices to prevent, control and
treat pollutants that affect communities and municipalities. We develop and
demonstrate cost-effective methods in the areas of sewage and wastewaters,
solid and hazardous wastes, and public drinking water supplies.
We recognize our responsibility to help establish and maintain
communications with our user community. We are also aware that every effort
must be made to reduce the time it takes to move research findings from the
laboratory to the user. This publication is one way for us to share with you our
research results. It briefly outlines our progress during 1978. Should you have
any comments about this publication, or suggestions for its improvement, please
take the time to write to me.
Francis T. Mayo
Director
Municipal Environmental Research Laboratory
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TABLE OF CONTENTS
Office of the Director 1
Solid and Hazardous Waste Research Division 7
Wastewater Research Division 29
Drinking Water Research Divisions 61
International Activities 77
IV
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OFFICE OF THE DIRECTOR
The MERL's Office of the Director provides management direction and administrative support to the
three line divisions of the Laboratory. In fiscal year 1978 special emphasis was placed in two areas. One
was a more complete integration of the planning process, and the other concerned program analysis.
INTEGRATING THE PLANNING PROCESS
While zero base budgeting (ZBB) has become the key Agency procedure for program planning,
laboratory participation comes at a later stage in the planning process. In 1978, the MERL Director and
senior staff made a concerted effort to become involved in the preparation of fiscal year 1979 (FY 79)
objective statements by the Office of Air, Land and Water Use (OALWU), and to guarantee that laboratory
accomplishment plans were reconciled precisely with Headquarters objectives. Joint OALWU/MERL
planning sessions contributed to mutual agreement and understandings that were reflected in laboratory
task work plans. That kind of cooperative effort will be extended to the FY 80 laboratory planning process.
Likewise the program review format has been changed from a task-by-task status report to a joint
OALWU/MERL discussion of program issues with participation from the EPA Program Offices, especially
in the area of identifying Program Office needs. That format and a desire on the part of MERL to modify
program plans to meet Agency research needs have positively influenced the research effort to be more
responsive in a timely manner to Program Office requirements.
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
Cincinnati, Ohio
SOLID & HAZARDOUS
RESEARCH DIVISION
Director — R. L. Stenburg
Disposal Branch
Chief: N. Schomaker
Processing Branch
Chief: Dr. A. Klee
OFFICE OF THE DIRECTOR
Laboratory Director — F. T. Mayo
Deputy Director — L. W. Lefke
WASTEWATER
RESEARCH DIVISION
Director—J J. Convery
Systems & Engineering
Evaluation Branch
Chief: Dr. C. A. Brunner
Technology Development Support
Branch, Chief: D. F. Bishop
Treatment Process Development
Branch, Chief: Dr. R L. Bunch
DRINKING WATER
RESEARCH DIVISION
Director — G. G. Robeck
Microbiological Treatment
Branch, Chief: E. Geldreich
Physical & Chemical Removal
Branch, Chief: Dr. J. Symons
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PROGRAM AND MANAGEMENT ANALYSIS
During 1976 and 1 977, much time and effort was spent in forming and consolidating the programs of
the Municipal Environmental Research Laboratory. In 1978 we were able to shift our Off ice of the Director
resources from organizing and procedures development to program and management analysis. Major
program areas covered were municipal sludge management, the toxics program and pathogen-virus
research coordination with other ERC laboratories. In the management improvement area, the laboratory
joined the ERC Personnel Office to undertake an intensive personnel management survey. A cost-saving
and dissemination-effective computerized mailing list was tested and put into operation. These and many
other management initiatives contributed to the continued success of managing an environmental
research and development laboratory that is assigned about 10% of all ORD dollars and manpower.
TABLE 1. MERL BUDGET FOR FY 1978 (IN $1,000'S)
PE #
AREA OF WORK
PFT POSNS. IN-HOUSE $
XM $
TOTAL
1BC611 WASTEWATER TREATMENT TECHNOLOGY 91
Combined Sewer Overflow
Urban Stormwater Impacts
Municipal Sludge Management
O&M
New Treatment Processes
Municipal Wastewater Reuse
Toxics Control
Small Wastewater Flows
1 CC614 WATER SUPPLY TREATMENT & SYSTEMS 33
MGMT.
Physical And Chemical Contaminants
Microbiological Contaminants
1DC618 SOLID & HAZARDOUS WASTE 18
MANAGEMENT
Land Disposal
Waste Residual Disposal Alternatives
Land Disposal Site Remedial Action
Hazardous Materials
Resource Recovery and Reuse
1HC619 ENVIRONMENTAL MANAGEMENT 5
1NE624 ENERGY-RELATED WASTE DISPOSAL —
Flue Gas Cleaning
Wastes-as-Fuels
2CB656 WATER SUPPLY-TECHNICAL ASSISTANCE 14
2DB661 SOLID WASTE-OSW —
XH1627 SOLID WASTE INTERAGENCY —
REIMBURSABLE
$3,045 $ 5,619 $ 8,664
1,472 4,780 6,252
1,137 5,637 6,774
165 309 474
— 1,025 1,025
325
305
34
325
305
34
TOTAL MERL
161
$6,144 $17,709 $23,853
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SUPPORTING THE RESEARCHERS
No laboratory can operate at a consistent high level of efficiency without a competent administrative
support staff. The OD staff insures that the operating divisions have the resources they need to do their job
by processing the documents necessary to obtain those resources. They expeditously handle purchase
requisitions for supplies and equipment, personnel matters to promote adequate staff, financial matters to
insure fiscal integrity, technical reports processing for information dissemination, and processing grants,
contracts and interagency agreements packages to fulfill Agency and other requirements. In 1978 the OD
installed a word-processing, shared-logic system to improve the timeliness and increase the efficiency of
extramural commitment registers, work plans, and numerous other administrative documents.
WHERE THE MERL DOLLARS WENT IN FY 78
Total MERL FY 78
Expenditures were
$23,852.8K
;in-House
;$6,144.3K
26%/^
Extramural
$17,708.5K
74% II!!!
Equipment—5%
All Other—5%
Supplies—4%
Printing—3%
Contracts—21%
Personnel
Costs
80%
EXTRAMURAL COSTS
IN-HOUSE COSTS
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COMPOSITION OF MERL WORKFORCE BY DISCIPLINE (DECEMBER 1978)
OTHER
SCIENTISTS
. 19
SECRETARIAL
SUPPORT
21
TECHNICIANS
AND AIDS
27
Professional Positions
Environmental Engineer 40
Chemist 30
Microbiologist 10
Chemical Engineer 8
Environmental Scientist 6
Operations Res. Analyst 3
Soil Scientist 3
Physical Science Adm 2
Community Planner 1
Economist 1
General Engineer 1
Mechanical Engineer 1
TOTALS 106
ADM SUPPORT—6
Support Positions
Secretary 17
Physical Science Aid/Tech 15
Engineering Aid/Tech 7
Biological Aid/Tech 4
Typist/Steno 4
Administrative Officer 1
Administrative Tech 1
Editorial Assistant 1
Equipment Mechanic 1
Management Assistant 1
Program Analyst 1
Extramural Prog. Asst. 1
TOTALS 54
OTHER PROFESSIONALS — 7
TABLE 2. MERL BUDGET FOR FY 1979 (IN $1,OOOS)
PE#
AREA OF WORK
PFT POSNS. IN-HOUSE $
XM $
TOTAL
1AD712 CARBON FIBER RESEARCH —
1BC821 URBAN SYSTEMS AND RESIDUALS MGMT. 52
Municipal Sludge Management
O&M
Toxics Control
1BC822 WASTEWATER SYSTEMS CONTROL 45
TECHN.
Combined Sewer Overflow
Urban Stormwater Impacts
New Treatment Processes
Municipal Wastewater Reuse
Small Wastewater Flows
1CC824 WATER SUPPLY TREATMENT & SYSTEMS 47
MGMT.
Physical and Chemical Contaminants
Microbiological Contaminants
1DC818 SOLID & HAZARDOUS WASTE 16
MANAGEMENT
Land Disposal
Waste Residual Disposal Alternatives
Land Disposal Site Remedial Action
Hazardous Materials
Resource Recovery and Reuse
1NE827 ENERGY-RELATED WASTE DISPOSAL —
Flue Gas Cleaning
Wastes-as-Fuels
— $ 600 $ 600
$1,913 4,350 6,263
1,562 11,559 13,121
1,847 4,789 6,636
772 5,142 5,914
265
265
TOTAL MERL
160
$6,094 $26,705 $32,799
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MERL RESOURCE TERMS
FY 79
$30M
$25M
$20M
During the four-year period
depicted in this chart, the dramatic
rise in $ resources has not been
accompanied by a personnel
increase. The MERL personnel
ceiling for FY79 is 160, exactly
the same as the FY76 PFT ceiling.
$15M
$10M
FY 76
FY77
FY 78
FY 79
Size and Composition of MERL Workforce by
Organization (December 1978)
WRD
DWRD
SHWRD
OD
KEY
Professional Staff
Technicians and Aids
Adm. & Clerical
40 60
Permanent Full Time
100
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MAN-YEARS OF EFFORT FOR MERL IN FY 78
Man-Years
100
Permanent Man-Years
Constitute 76% of the
Total Work Effort, While
Temporary Man-Years are
24% of the Total Effort
Shaded Area = Permanent Man-Years
Unshaded Area = Temporary Man-Years
100
90
80
70
60
50
40
30
20
10
WRD
DWRD
SHWRD
OD
MERL
PERM. M.Y.
TEMP. M.Y.
TOTAL M.Y.
87.0
21.9
108.9
38.9
16.4
55.4
16.4
5.8
24.2
13.2
4.5
17.7
155.3
48.6
203.9
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SOLID AND HAZARDOUS WASTE RESEARCH DIVISION
The Solid and Hazardous Waste Research Division (SHWRD) conducts research in three major
functional areas: disposal technology, hazardous wastes, and resource recovery. In the past, solid waste
research was concentrated on problems associated with municipal solid waste. With present efforts
directed primarily toward the environmental effects of hazardous waste disposed onto or into the land our
research has concentrated on disposal or treatment technologies that will minimize or prevent harmful
effects.
The problems of solid waste disposal are interrelated with those of air and water pollution. Incineration,
grinding, the use of water either for transportation of solids or as a solid waste sink—these impinge upon
the concurrent attempts to purify the air and water environments. Additionally, the elimination of
impurities from air or water effluents by such processes as separation, drying, or compaction, results in
the generation of solid wastes—solids that, in turn, require disposal. Measures to reduce pollution or
disposal of waste material must, therefore, be taken with full consideration of the effect on the overall
environment—air, water, and land.
The solid waste problem is concentrated in densely populated urban areas. Refuse storage, collection,
transportation, and processing directly and intimately affect some 80% of the population. The costs of
waste handling, already severe, are rising. The loss of billions of tons of material to unreclaimed waste
each year indirectly affect each consumer.
Even more threatening in terms of public health and environmental effects are the present disposal
practices for hazardous wastes. Current estimates indicate that 30to35 million tons of hazardous wastes
are disposed of to the ground with no controls, no records as to location, quantity, and composition. Atthe
present time, proven techniques for large-scale disposal of most, if not all, hazardous wastes are not
available and generators of these wastes have little incentive to expend resources for adequate
management.
Municipalities and other governmental agencies need new and improved systems for storage,
collection, and transportation of solid waste; improved technology or methodology for waste reduction;
and criteria for site selection, design, and operation of landfills.
WASTE DISPOSAL
Increasing amounts of waste residuals are being
directed to the land for disposal by landfilling. The
waste disposal program of SHWRD has been
designed to document and evaluate the potentially
adverse environmental and public health effects
that could result if precautions are not taken for
handling the leachate and gas produced in the
course of landfilling. This SHWRD research—
encompassing state-of-the-art documents,
laboratory analysis, bench and pilot studies, and
full-scale field verification studies—will result not
only in research reports and criteria and guidance
documents for user communities, but also in a
criteria data base for the development of standards
as mandated by the recently enacted Resource
Conservation and "Recovery Act of 1976." The
current research activities as classified and
discussed here are:
1. Waste Characterization/Decomposition
2. Pollutant Transport
3. Pollutant Control
4. Pollutant Treatment
5. Co-disposal
6. Environmental Assessment
7. Remedial Action for Inoperative Sites
8. Landfill Alternatives
9. Economic Analyses
WASTE CHARACTERIZATION/
•DECOMPOSITION
Studies in this area involve collecting
composition data on municipal and hazardous
wastes from individual wa'ste residuals and landfill
disposal sites. The study objectives are to (1)
quantify the gas and leachate production from
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current best-practice sanitary landfilling and (2)
modify the landfill method to reduce the
environmental impact of gas and leachate
production in a positive and predictable manner.
These objectives are to be achieved by
construction and long-term monitoring of typical
and simulated landfill cells (Figure 1) and
investigation, development, and optimization of
those factors that control gas, and leachate
production. Results are expected only after
longterm monitoring, due to the extremely slow
reaction rates.
Standard Techniques
Procedures for analyzing contaminants in
leachate samples are being developed, both
specific to the wastes being studied a nd for general
use. In studying the potential environmental
impact of contaminants, a standard test is being
planned to assess contaminants leached from a
waste by water and other solvents, both initially
and over time.
Waste teachability
One study involves the determination of long-
term gas and leachate generation characteristics
by leaching 437 tons of municipal refuse and
comparing the results to those obtained for
monitoring 117-ton and 3-ton experimental
landfills, all at the Boone County Field Site (BCFS)
of USEPA. Leachate collected form the 437-ton
BCFS landfill (Figure 2) has carried from the
landfilled waste the following mass of
contaminants: 16,600 kg COD; 1,000 kg Ca; 607
kg Cl; and 440 kg Na. Based on these results, the
mass release of contaminants form landfilled
refuse are estimated to be 63.1 gm COD/cap/day;
3.8 gm Ca/cap/day; 2.3 gm Cl/cap/day; and 1.7
gm Na/cap/day. The 5 day BOD of raw domestic
wastewater has been estimated at 54
gm/cap/day.
Survival of poliovirus in landfill refuse was
investigated at BCFS and the Center Hill Facility.
Studies showed the presence of this virus in
municipal solid waste in leachates when the waste
was surcharged with large volumes of water.
Poliovirus-seeded refuse samples were exposed to
landfill conditions for 10 or more days but no
poliovirus survived or was found in the leachate.
The high ambient temperatures (air = 35°C; refuse
= 59°C) were assumed to be the principal cause of
virus inactivation.
Another ongoing leachability study deals with
inorganic industrial waste in which there is no
appreciable biological activity. Consequently, the
chief mode of decomposition and pollutant release
is sol ubi li zat ion and other strictly
chemical/physical changes rather than the
Figure 1. Experimental Landfills for Waste Decomposition Studies.
8
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Figure 2. Construction of Leachate Collection System for the 437-Ton BCFS Experimental Landfill.
biological decomposition that takes place as the
waste is leached with water. Accordingly, the
testing program is designed to evaluate leaching
and pollutant release through time under a variety
of leaching conditions encountered in one or more
disposal situations.
Results to date are consistent with findings from
other projects that leachability of inorganic wastes
is a function not only of the constituent of interest,
but also of the surface area per unit weight of
waste and the stability of the compounds formed
during waste treatment. The variability in degree of
buffering against solvent-induced changes
dictates that the time dependent leachability also
be considered. Figure 3 is a schematic of
sequential leaching and sorption procedure being
tested with the various inorganic wastes.
Waste Decomposition
A laboratory study is designed to examine the
role of waste moisture content and net infiltration
in waste decomposition (Figure 4). It has yielded
information on the rates and duration of waste
decomposition, including gas and leachate
production.
It was found that increasing the moisture
content of refuse increased the rate of gas
production. A similar effect was also produced by
increasing temperature and decreasing the size of
the solid waste particles. Calculation of the
activation energies indicated that the overall
reaction rate was chemically controlled. The
effective life of a landfill, during which gas can be
extracted at a rate of 20 ml/kg dry wt./day was
estimated to be 17 years after deposition.
Increasing the rate of infiltration gas had only a
minor effect on the total mass of contaminants
leached from refuse; the rate of release, however,
was found to be directly proportional to the rate of
infiltration.
Also being studied are the effects of different
waste processing techniques on gas and leachate
production during waste decomposition. Raw
refuse, shredded refuse, and baled refuse are
being investigated in a simulated landfill
environment. Processing of waste has been found
to have very pronounced effects on the rate of
contaminant mass leached from refuse. Baling
appears to have very little effect on the rate of mass
release, but shredding tends to accelerate the
mass release of contaminants.
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Refilter Portion
Through MiHiporf
and Analyst;
Figure 3. Flow Chart for Graded Serial Batch Extraction.
POLLUTANT TRANSPORT
Pollutant transport studies examine the release
of liquid and gaseous pollutants from various
municipal and hazardous wastes and the
subsequent movement and fate of these pollutants
in soils adjacent to disposal sites. Although the
potential for damage in general can be
demonstrated, migration patterns of contaminants
and consequent damages that would result from
unrestricted landfilling at specific sites cannot be
accurately predicted. The ability to predict must be
developed in order to justify required changes in
the design and operation of disposal sites,
particularly for any restriction of co-disposal of
municipal and industrial wastes. Both laboratory
and field verification studies are being performed
to assess the potential for ground-water
contamination. The studies will provide the
information required to (1) select land disposal
sites that will naturally limit release of pollutants to
the air and water and (2) make rational
assessments of the need for and cost-benefit
aspects of leachate and gas control technology.
The overall objective of this activity is to develop
procedures for using soils as possible limiting or
delaying media for the movement of pollutants.
Consequently, a significant number of SHWRD-
funded research projects focus on understanding
processes and predicting the extent of migration of
contaminants (chiefly heavy metals) from land
disposal sites.
Controlled Laboratory Studies
One project is studying the movement in soils of
contaminants present in landfill leachates,
possibly introduced or increased in concentration
by co-disposal of municipal and hazardous wastes.
These contaminants are: arsenic, beryllium,
cadmium, chromium, copper, cyanide, iron,
mercury, lead, nickel, selenium, vanadium, and
zinc.
The attenuation of the substances listed above
was found to be a function of their individual
properties and of the permeability of the soil and
the amounts of clay, lime, and hydrous iron oxides
present in the soil. Iron was also studied; its
movement and retention were most closely
correlated with the amounts of clay and hydrous
iron oxides in soil. Amounts of elements retained
by soils against subsequent extraction with water
and 0.1 N HCI suggest substantial permanent
retention capacity for soils. Total Organic Carbon
(TOC) and Chemical Oxygen Demand (COD) in
unspiked leachates were not significantly retained
by any soils.
10
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Figure 4. Bench-Scale 55-Gallon Experimental Landfill Lysimeters to Determine the Effect of
Moisture Regime, Particle Size, and Temperature on Gas Production.
Another project is studying the removal of
contaminants from landfill leachates by clay
minerals. Columns were packed with mixtures of
quartz sand and clay minerals. The leaching fluid
consisted of typical municipal refuse leachate
without metal salt additives. The general approach
differed from that of the preceding project effort in
that (1) both sterilized and unsterilized leachates
were utilized to examine the effect of microbial
activity on hydraulic conductivity and (2) batch
studies of the sorptioo of metals from leachate by
clay minerals were conducted. The column study
results indicated that Cl, Na, and water-soluble
organic compounds (COD) were relatively
unattenuated by passage through the clay-sand
columns; K, NH4, Mg, Si, and Fe were moderately
attenuated; and heavy metals — such as Pb, Cd,
Hg, and Az — were strongly attenuated by even
small amounts of clay. Concentrations of Ca, B,
and Mn in the column effluents increased
markedly over the original leachate
concentrations.
Montmorillonite was found to have the highest
attenuation capability, followed by illite and then
kaolinite. Precipitation was found to be the
principal attenuation mechanism for the heavy
metals Pb, Cd, Hg, and Zn. The cation exchange
capacity of the clay minerals was concluded to be
the dominant attenuation mechanism responsible
for the removal of other substances from the
leachate.
The batch studies involved adsorption of Cr, Cu,
Pb, Cd, Hg, and Zn by montmorillonite and kaolinite
from water solutions and from landfill leachate.
The adsorption in leachate proved to be 50 to 90%
lower in most cases than the clays' adsorption
capacity for the metal ions in pure aqueous
solutions. Precipitation of the heavy metal cations
was found to be an important attenuation
mechanism while adsorption was the principal
mechanism for the anions over the entire pH range
studied. Pollutant adsorption by clay minerals(and
hence the mobility of pollutants in clays and clay
soils) was significantly affected by other, non-
hazardous solutes in the leachates.
A model for predicting movement in soil of the
landfill gases methane and carbon dioxide has
been developed and used to evaluate several types
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of gas control procedures for protecting buildings
adjacent to landfills. Generally, passive
procedures such as gravel trenches are not as
satisfactory as active procedures where air is
pumped into or out of a trench or well. This model
and its predictions are to be field tested during the
next year. Another effort includes study of wastes
from the following industries: electro-plating, in-
organic pigments, water-based paints, nickel-
cadmium batteries, chlorine, lead-acid batteries,
carbon-zinc primary batteries, hydrofluoric acid,
phosphorous, aluminum fluoride, titanium
pigments, re-refining of used petroleum, and flue
gas desulfurization. The potential for contaminant
migration through soil from these wastes was
being examined by the traditional soil column
techniques. While these yielded useful
information on soil contaminant interactions, the
work was time consuming and difficult to replicate.
As a consequence, sequential batch procedures
have been developed and are being tested. The
previous shown figure (Figure 3) illustrates how
waste leachates and soils are contacted using
these procedures.
In the area of organic bontaminants, project
results indicate that PCBs were immobile in all
soils when leached with aqueous solvents (water
and minicipal landfill leachate); they were highly
mobile in all soil materials when leached with
organic solvents. The rate of adsorption of PCBs by
soil materials was found to be rapid, with
equilibrium conditions achieved in less than 8
hours. The adsorption process conformed to the
Freundlich adsorption equation. PCBs were found
to be strongly adsorbed by soil materials. The
adsorption capacity and the mobility of PCBs were
positively correlated to the organic carbon content
and surface area of the respective soil materials.
Other organic contaminant work studied the
volatilization of hexachlorobenzene (HCB) out of
wastes from manufacture of perchloroethylene
and carbontetrachloride. Flux of HCB into the
atmosphere could be controlled by soil covers
compacted over landfills. Figure 5 is a flow diagram
of the suggested process for designing a soil cover.
The project also determined that the organic
solvent fraction of the waste could be a significant
source of HCB release.
Field Verification
Limited field verification is being conducted. The
initial effort investigated the current assumptions
about the effectiveness of clays and other fine-
textured earth materials in restricting the
movement of contaminants into groundwaters.
This work examined patterns of contaminant
migration around two secondary zinc smelting
plants and an organic chemical manufacturing
plant that are storing or disposing of wastes on
land. The migration of metals (zinc, cadmium,
copper, lead) that occurrred at the three smelters
has been limited by attentuation processes to
relatively shallow depths in the soil profile (~ 12
feet). Cation exchange and precipitation of
insoluble metal compounds were determined to be
the principal mechanisms controlling the
movement of metals through the soil. At the
organic chemical manufacturing site, it appeared
that the glacial materials were retarding the
migration of organic pollutants. No organic
pollutants were detected in the shallow
groundwater system. Soil coring was found to be a
useful tool, but not suitable by itself for routine
monitoring of waste disposal activities.
Another effort has consisted of installing
monitoring wells and coring soil samples adjacent
to three municipal landfill sites to identify
contaminants and determine their distribution in
the soil and groundwater. The sites represent
varying geologic conditions, recharge rates, and
age, ranging from a site closed for 15 years to a site
currently operating. The results of the study
indicated that changes in chemical composition of
the groundwater could be related to the position of
the borings with respect to the landfills. Water
quality below and down the groundwater flow
gradients showed increased levels of sulfate (all
sites), nitrates, TOC, and cyanide. There were no
changes in the soil physical parameters that could
be attributed to the landfill. No evidence was found
in this study to substantiate the idea that sub-
landfill soils seal themselves.
POLLUTANT CONTROL
The pollutant control studies determine the
ability of in-situ soils, ranging from sands to clays,
and natural soil processes to limit the transport of
leachate contaminants as the leachate migrates
from landfill sites through the soil. The studies also
determine how various synthetic and admixed
materials can be utilized as liners to prevent
leachate migration. The overall objective is to
enable minimization of sub-surface pollution,
particularly of groundwater.
Liners/Membranes/Admixtures
The test program will evaluate, in a landfill
environment, the chemical resistance and
durability of liner materials over 1 2-, 24-, and 36-
month exposure periods to leachates derived from
hazardous wastes, SOX wastes, and municipal
solid wastes. The liner materials being
investigated for municipal solid wastes include six
admixed materials.
72
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BEGIN
Estimate minimum reasonable density for
soil cover and calculate corresponding porosity
(Eqn. 10) assuming all porosity is air-filled.
Estimate maximum density for soil cover and
calculate the corresponding porosity assuming
that all porosity is air-filled. (Eqn. 10)
f
NO
1
NO
Using the porosity corresponding
to maximum density, use Eqn 1 1
and the minimum water content
to calculate air-filled porosity
Are soils or soil
materials (e.g.
Bentomte) available}-*-
for modifying or
substituting for
on-site soils?
-NO YES"
! L
'-NO
Using the air-filled
porosity and Eqn 5,
s the required soil
depth technically and
economically feasible'
Is data available
to estimate
minimum water
content?'
' YES"
YES
Using the porosity corresponding
to minimum density, use Eqn. 11
and the minimum water content
to calculate air-filled porosity.
I NO
Using the air-filled
porosity and Eqn. 5,
is the required soil
depth technically and
economically feasible?
YES-
YFS-
Repeat process for
modified cover material.
Soil cover will not limit flux
to acceptable value.
Seek other method for dealing
with waste.
Develop landfill
design plans.
'At this stage, could consider irrigation or
other treatment to maintain higher water
content {if allowed by regulatory agency/.
Figure 5. Flow Diagram for Predicting Depth of Soil Cover Required to Limit Vapor Flux Through Soil
Cover to an Acceptable Value.
2 asphalt concretes (varying in permeability),
1 soil asphalt,
2 asphalt membranes (one based on an
emulsified asphalt and the other on
catalytically-blown asphalt),
1 soil cement;
and six flexible membranes:
butyl rubber,
ethylene propylene rubber (EPDM),
chlorinated polyethylene (CPE),
chlorosulfonated polyethylene (HYPALON),
polyethylene (PE), and
polyvinyl chloride (PVC).
Results of the first 12 month's exposure to
municipal solid wastes produced only minor
changes on the physical properties of the liner
materials exposed to landfill leachate. With the
exception of polyethylene and ethylene propylene
diene monower, all liner materials had small
losses in tensile strength. The heat sealed seam
retained their strength the best while some major
losses were observed in other seaming
techniques. In all cases the liner materials
softened. None of the polymeric materials allowed
leachate to pass during the first year exposure
although leakage was observed through the soil
13
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asphalt and asphalt concrete liner materials. Liner
materials for hazardous waste disposal sites will
be tested in rectangular, epoxy-coated steel cells
(25 cm by .38 cm), with about 30 cm of hazardous
waste above the material being tested. A number
of polymeric membranes and admixed materials
are under consideration for study as primary liner
materials. The first year's results of liner materials
exposed to hazardous wastes produced some
drastic changes in the asphaltic type liners. Strong
acid and a strong base caused these asphaltic liner
materials to fail. Strong acid also caused the soil
cement type liner to fail. The effects of the wastes
upon the polymeric membrane linings varied
considerably with the polymer and the waste. Oily
type wastes generally degrade flexible membranes
unless specifically compounded to contain this
class of wastes. Although the results of the first
year's exposure must be considered preliminary, it
is quite apparent that some of the hazardous
wastes used in this study can seriously affect the
physical properties of lining materials. This
reinforces the concept of testing specific liner and
waste combinations for compatibility.
The final liner study involves materials for sites
receiving sludges generated by the removal of
sulfur oxides (SO*) from flue gases of coal burning
power plants and will differ from studies for
municipal and hazardous waste. Methods of lining
such disposal sites must have a low unit cost, and
materials should be easy to apply. Because of
these considerations, fewer polymeric membranes
have been included in the study, the emphasis
being on admixed and sprayed-on materials.
Results to date at the midpoint oithe study indicate
that two of the admixed liners (M179 and Guartec)
had disintegrated due to reaction with the sludge.
The sludge which was thought to be an acceptable
liner material itself did not act as a liner nor did it
seal the soil as expected.
Chemical Stabilization
Chemical stabilization is achieved by
incorporating the solid and liquid phases of the
waste in a relatively inert matrix that protects the
components of the waste from dissolution by
rainfall or other water in the soil.
If this slows the rate of contaminant leaching
sufficiently to render the waste essentially
harmless, then restrictions on disposal site
location can be minimal. The test program consists
of investigating five industrial wastes, in both the
raw and fixed states. Each waste was treated in
five separate fixation processes and subjected to
physical testing for leachability. Results to date
indicate that leaching of fixed wastes is a function
of physical, chemical, and biological mechanisms
and principally occurs in the following two ways:
1. External leaching which occurs primarily
as surface washing and/or as diffusion
into surface flow.
2. Internal leaching which is primarily a
function of the solubility of the material.
Since most fixed wastes are characterized as
being highly impermeable; then in a field disposal
situation the internal leaching contributes an
insignificant mass of contaminants to the
environment. External leaching is the predominant
mechanisms for contaminant mobility from fixed
waste disposal areas. As primarily stated, this
external leaching is a combination of surface
washing and/or diffusion to surface flow.
Fixation of sludges will generally result in an
improvement in leachate quality because of the
inherent physical and chemical properties of the
fixed wastes as compared to the raw sludges. The
primary factor contributing to improvement in
leachate quality from fixed wastes is the reduction
in raw waste surface exposed to leaching. This fact
generally results, not only in lower leachate
concentrations, but also in a significant
improvement in the total mass of contaminants
released to the environment.
Co-disposal of the fixed waste with municipal
refuse is also being investigated. Chemically
stabilized industrial sludges have been loaded into
large lysimeters with municipal solid waste (Figure
6). These lysimeter systems will simulate landfill
conditions. Differences in leachate quality
between untreated sludges, stabilized sludges,
and MSW without sludges are being determined.
Figure 6. Chemically Stabilized Sludge Placed
Into a 6-Foot Diameter Simulated
Landfill Lysimeter.
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POLLUTANT TREATMENT
The pollutant treatment studies relate to
physical, chemical, or biological treatment of
collected leachate prior to discharge from the
landfill site. The overall objective is to develop
technology that treats the landfill leachate after
collection and containment at the landfill site.
Physical-Chemical Treatment
Physical-chemical treatments tested in the
laboratory include chemical precipitation,
activated carbon adsorption, and reverse osmosis.
The activated carbon was quite effective in
removing refractory organics in the effluent of
biological treatment systems. In general, physical-
chemical treatment processes have been found to
be most effective in polishing the effluent from
biological systems treating municipal landfill
leachate and in treatment leachate from stabilized
old landfills.
An ongoing laboratory study is evaluating
various materials that could be utilized to retard or
minimize migration of pollutants from disposal
sites. Agricultural limestone, hydrous oxides of
iron (ferrous sulfate mine waste), lime-sulfur oxide
(stack-gas waste), and certain organic waste are
included in the studies. Results to date indicate
that linings of crushed limestone retard movement
of metallic, cation-forming trace elements more
effectively than anion-forming trace elements.
MSW leachate characteristics influence the
effectiveness of limestone linings. Information to
date is not sufficient to design a lining to "treat" a
given amount of leachate. Though effective in
retardation, hydrous iron oxides may create
additional problems due to the release of reduced
iron.
Biological Treatment
Various biological processes have been studied
in the laboratory for the treatment of leachate. The
process kinetics, the nature of the organic fraction
of leachate, and the degree of treatment that may
be obtainable using conventional wastewater
treatment methods have been investigated. The
biological methods evaluated were the anaerobic
filter, anaerobic and aerated lagoons, and
combined treatment of municipal landfill leachates
and municipal sewage using activated sludge.
Biological units were operated successfully
without prior removal of the metals. Leachate from
recently constructed landfills was best treated by
aerobic or anaerobic, biological treatment
processes.
CO-DISPOSAL
Presently, little is known of the effects of co-
disposal (industrial waste with municipal solid
waste) on the decomposition process and the
quantity and quality of gases and leachate
produced during decomposition in landfills. There
is a strong concern that the addition of industrial
wastes to municipal waste landfills will result in
elevated metal concentrations in the leachates
and, potentially, in groundwaters. Advocates of co-
disposal believe that the presence of organics in
the landfill will immobilize heavy metals and that
the presence of industrial sludges may accelerate
the decomposition process and shorten the time
required for biological stabilization of the refuse.
Because of the high moisture content and,
commonly, the high pH and alkalinity of these
sludges, periodic analyses of the leachates for
trace and heavy metals over a long period will be
required to provide data to allow rational
evaluation of co-disposal. The objective is,
ultimately, to predict the patterns of chemical and
microbiological transformations involving such
contaminants.
The initial effort involves a study of the factors
influencing the effect of admixing industrial
sludges and sewage sludge with municipal refuse.
A combination of municipal solid waste and
various solid and semi-solid industrial wastes was
added to several field lysimeters (large-scale test
cells). All the contents were measured and
characterized to obtain relations to leachate
quality and quantity, gas production, and microbial
activity. Results of this ongoing effort have yielded
the following observations:
1. The addition of sewage sludge to landfilled
municipal refuse may enhance the rate of
mass release of organic matter if less than
per capita equivalent production quantities
of sludge are added. At equivalent per
capita production, no difference has been
noted.
2. No great differences in the rate of
contaminant mass release by leaching has
been noted for inorganic pigment waste.
3. Addition of electroplating waste increased
the mass flux of COD, total solids, Cl, Cu,
Cr, and Ni.
4. Heavy metals and salt mass flux resulting
from the addition of chlorine production
sludge were noticeably greater than from
refuse only.
5. Heavy metals were leachated in greater
quantities when electroplating waste was
disposed with municipal refuse.
6. Adecrease inthe massflux of contaminant
was noted when biologically active
petroleum sludge was added to refuse.
A second effort involves the leaching of
industrial wastes using municipal landfill leachate
and water. Results to date indicate that municipal
15
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landfill leachate solubilizes greater amounts of
metals from the wastes and promotes more rapid
migration of metals through soil than does water.
Studies on industrial wastes, coal flyash, and
sludges generated by removing sulfur oxides from
power plant flue gases are being planned as a
continuation of this project.
A study to evaluate co-disposal of chemically
stabilized sludges in a municipal refuse landfill is
also under way and was discussed under the
chemical stabilization section.
ENVIRONMENTAL ASSESSMENT .
Studies of the environmental effects of waste
disposal to the land in relation to management and
disposal practices for municipal solid wastes have
been initiated. The overall objective is to enable the
prediciton of environmental effects.
Vegetative kills and growth problems associated
with landfill gas migration have been evaluated.
Additional investigations will determine measures
for reducing vegetation losses and those
vegetation species best suited to landfill environs.
Another project is determining the important of
milled refuse particle sizes for a landfill operated
without daily cover. The overall objective is to
establish operation and maintenance parameters
to minimize detrimental environmental effects.
Variables to be evaluated are: the effect of wind
velocities and direction on the movement of
landfilling material; the amount of differential
settling associated with size variations; the initial
and subsequent densities with relation to time and
consolidation within each test cell and the
presence or absence of surface crusting; nuisance
organisms, wildlife, and the type and amount of
plant growth; and odors and background
conditions potentially responsible for odors.
REMEDIAL ACTION FOR INOPERATIVE
SITES
The Office of Solid Waste has recently concluded
the investigation of 391 damage cases traceable to
waste disposal. Fifteen percent of these cases
involved groundwater pollution from hazardous
waste landfills, 25% involved groundwater
pollution from indiscriminate dumping practices,
and 40% involved leachate problems. Nine percent
or 35 of the 391 damage cases, involved well
pollution. In order to determine the best practical
technology and economical corrective measures to
remedy these pollution problems, a research effort
to provide users with the descriptions and costs of
corrective measures has been initiated. Phase I
will be an engineering feasibility study that will
determine on a site-specific basis the best
applicable existing neutralization or confinement
techniques. Phase II will determine the
effectiveness, by actual field verification, of Phase,
I. Phase III will provide a site remedial guide to local
municipalities and users. The Phase I effort has
produced a guidance manual to assist user
communities in the selection of available
engineering technology to reduce or eliminate
leachate generation at inoperative landfills. Five
categorical areas are discussed. Surface water
control, groundwater control, plume management,
chemical immobilization and excavation/reburial.
LANDFILL ALTERNATIVES
Although municipal solid wastes are normally
incinerated or deposited in standard sanitary
landfills, other options are necessary for more
hazardous materials. Among the alternatives
being considered are: (1) deep well injection, (2)
underground mines, (3) land cultivation, and (4)
saline environments. Alternatives 1 and 2 are
primarily orientated toward hazardous wastes.
Deep Well Injection and Underground Mines
Available information has been compiled on the
injection of industrial hazardous wastes into deep
wells and the placement of such wastes in
underground mines. Results of the latter study
showed that a majority of the nonradioactive
hazardous wastes considered can be acceptably
stored if properly treated and containerized. In the
United States, room and pillar mines in salt,
potash, and gypsum appear to be most favorable
for storage. Systems adequate to detect, monitor,
and control waste migration are available or can be
developed from current technology.
Land Cultivation and Saline Environments
The disposal technique of land cultivation,
whereby specific waste residues have been
directly applied or admixed into soils, has been an
alternate disposal option for many years by
pharmaceutical, tannery, food processing, paper
and pulp, and oil refinery industries. To assess this
concept, various research efforts have been
initiated. The initial state-of-the-art document
indicated that application of shredded municipal
refuse or compost to marginal or drastically
disturbed land improves soil structure and fertility,
thus making revegetation possible. It appears that
the environmental pollution caused by land
cultivation is minimal as compared to that for
landfills, primarily due to maintenance of aerobic
conditions and the lower concentration of waste
per unit area of land.
The second effort is a combination laboratory,
greenhouse and field study to determine the fate
and mobility of wastes in soil for the purpose of
16
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developing criteria for use in the design,
management and monitoring of land cultivation
disposal operations. Decomposition rate,
application rate, plant survival and growth,
pollutant runoff and leachate generation will be
obtained in development of data base.
The third effort relates to detailed field surveys
and limited laboratory field experimentation for the
purpose of developing a matrix of industrial
organic and inorganic and municipal waste
streams versus operational parameters. This
matrix of information will be used to develop
design and guideline criteria.
Information available on the disposal of
municipal solid waste in saline environments, i.e.,
estuaries and coastal marchlands, is also being
obtained. Case studies will be collected and state
regulations and policies will be compiled for those
states bordering saline waters. The effort is
primarily a paper study detailing the present
environmental and economic status of this type of
disposal option.
ECONOMIC ANALYSES
The use of market-oriented incentive
(disincentive) mechanisms has received very scant
consideration for pollution control policy in the
United States, particularly in the area of hazardous
waste management. Economic theory suggests
that incremental pricing of waste collections and
disposal would reduce the waste generation rate,
enhance source separation of recyclable
materials, accelerate technological innovation,
and minimize total system cost.
The economic relevance is being addressed
hazardous waste management in general and the
environmental impact aspect is being addressed to
flue gas cleaning (FGD) sludge disposal.
In the economic relevance effort currently being
investigated, a methodology is being developed
that permits economic. and social impacts of
alternative approaches to hazardous waste
management to be addressed. The procedure
involves generation of a series of environmental
threat scenarios that might arise from the use of
different hazardous waste management
techniques. The costs attributable to any
technique comprise the control costs, and the
environmental costs and benefits together
determine the net benefits associated with the
threat scenarios.
In the environmental impact effort the problem
of FGD sludge disposal to the land has been
addressed. This effort considered the problem from
a potential regulatory approach by evaluating the
existing data base and projecting its potential
impact on the promugation of sludge disposal
regulations.
REFERENCES
1. Brunner, D.R., LEACHATE PRODUCTION AND ITS CONTROL, presented at Kentucky State Solid
Waste Managers Meeting, Florence, Kentucky, September 28, 1978.
2. Chan, P.C., et al., SORBENTS FOR FLUORIDE, METAL FINISHING, AND PETROLEUM SLUDGE
LEACHATE CONTAMINANT CONTROL, EPA-600/2-78-024, March 1978.
3. Chian, E.S.K. and DeWalle, F.B., EVALUATION OF LEACHATE TREATMENT; VOLUME I -
CHARACTERIZATION OF LEACHATE, EPA-600/2-77-186a, September 1977.
4. Chian, E.S.K. and DeWalle, F.B., EVALUATION OF LEACHATE TREATMENT; VOLUME II -
BIOLOGICAL AND PHYSICAL-CHEMICAL PROCESSES, EPA-600/2-77-186b, November 1977.
5. Flower, F.B., Leone, I.A., Oilman, E.F. and Arthur, J.J., A STUDY OF VEGETATION PROBLEMS
ASSOCIATED WITH REFUSE LANDFILLS, EPA-600/2-78-094, May 1978.
6. Landreth, R.E., RESEARCH OF IMPOUNDMENT MATERIALS, presented atthe First Annual EPA/AES
Conference on Advanced Pollution Control forthe Metal Finishing Industry, Orlando, Florida, January
17-19, 1978; also presented at the EPA/Coastal Zone Task Force Workshop on Oil Spill Debris
Disposal, Boston, Massachusetts, February 22, 1978.
7. Landreth, R.E., LINERS AND CHEMICAL FIXATION, presented at Allied Chemical Corp., Morristown,
New Jersey, September 26, 1978.
8. Lowenbach, W., COMPILATION AND EVALUATION OF LEACHING TEST METHODS, EPA-600/2-78-
095, May 1978.
9. Roulier, M.H., USE OF POLLUTANT MOVEMENT PREDICTIONS TO IMPROVE SELECTION OF
DISPOSAL SITES, presented at the 4th Annual Research Symposium on Land Disposal of Hazardous
Wastes, San Antonio, Texas, March 6-8, 1978.
10. Sanning D.E., and Woodyard, J.P., THE ENVIRONMENTAL IMPACT OF FGD SLUDGE DISPOSAL,
presented at Air Pollution Control Meeting, Houston, Texas, June 1978.
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11. U.S. Army Engineer Waterways Experiment Station, CHEMICAL AND PHYSICAL EFFECTS OF
MUNICIPAL LANDFILLS ON UNDERLYING SOILS AND GROUNDWATER, EPA-600/2-78-096, May
1978.
12. Ware, S.A. and Jackson, G.S., LINERS FOR SANITARY LANDFILLS AND CHEMICAL AND
HAZARDOUS WASTE DISPOSAL SITES, EPA-600/9-78-005, May 1978.
13. Wiles, C.C. and Klee, A.J., BACTERIAL AND VIRAL EMISSIONS IN PROCESSING MUNICIPAL SOLID
WASTE, presented at Air Pollution Control Meeting, Houston, Texas, June 1978.
14. Woodyard, J.P. and Sanning, D.E., ECONOMICS OF DISPOSAL AND THE COMPILATION OF A DATA
BASE FOR STANDARDS/REGULATIONS OF FGD SLUDGE, presented at the 4th Annual Research
Symposium on Land Disposal of Hazardous Waste, San Antonio, Texas, March 6-8, 1978.
RESOURCE RECOVERY
SHWRD is charged with the responsibility for (1)
resource recovery research and development
(including materials and energy recovery), (2)
waste reduction, and (3) hazardous materials
treatment and processing. The multifaceted
resource recovery programs involve research to
determine and develop the best techniques for the
recovery and reuse of the material and energy
values contained in municipal solid waste.
Currently, the program involves research in seven
basic areas:
1. Refuse Derived Fuels
2. Evaluation of Resource Recovery Facilities
3. Technology Assessment
4. Process Equipment Evaluations
5. Selected Waste Utilization
6. Environmental Impacts
7. Special Studies under the Resource
Conservation and Recovery Act (PL 92-
580)
REFUSE DERIVED FUEL
This research involves extracting the
combustible organic fraction of municipal solid
waste, processing it into an easily handled form,
and investigating its combustion characteristics in
industrial, institutional, and utility boilers.
Research priorities include co-firing of refuse
derived fuels (RDF) and coal; investigating
chemical andthermal processesfor improving RDF
fuel quality; onsite combustion tests to determine
environmental emissions, plant modifications, and
equipment requirements; development of
standard sampling and testing procedures, and
specifications for a standardized RDF and d-RDF
(densified). With increasing experience and
knowledge, the marketability and acceptability of
RDF should improve, making it a promising
resource recovery alternative.
SHWRD is cooperating with others to help
increase the acceptability of the concept.
Cooperative projects are being implemented with
the EPA Industrial Environmental Research
Laboratory (IERL) in Cincinnati to evaluate special
aspects of the Madison and Milwaukee, Wisconsin
resource recovery systems dealing with the use of
RDF. Additionally, IERL and SHWRD are
cooperating with the State of Maryland in a project
to use RDF as a fuel in cement kilns. The State of
Maryland also cooperated with SHWRD in the first
phase combustion test of densified refuse derived
fuels in the Maryland Correctional Institute's
stoker boiler located near Hagerstown, Maryland.
Industry is also cooperating as the second phase
tests of d-RDF will be conducted in an industrial
boiler located in Erie, Pennsylvania. To further this
cooperation, SHWRD provided 60 tons of d-RDF to
be tested at a state boiler in New York. SHWRD also
conducted studies jointly with the Department of
Energy to provide information on mixing
techniques for the anaerobic digestion of mixtures
of solid waste and sewage sludge for producing
methane gas.
RESOURCE RECOVERY FACILITIES
Several research projects are directly concerned
with the design, implementation, testing, and
evaluation of planned or existing resource
recovery facilities.
The City of Ames, Iowa received a grant from
SHWRD to evaluate the city resource recovery
system. Research includes statistically designed
experiments to investigate air emissions from RDF
combustion, boiler corrosion, burnouts, and boiler
and plant operations. Figure 7 diagrams the
sampling points on the stoker-fired boilers at the
Ames facility.
The project is providing the first long-term data
available on the effects of RDF on the corrosion of
boiler tubes. Tubes placed in situ have been
removed after 1,000 hours and 1 year of exposure
to the combined combustion of RDF and coal.
Analyses have indicated virtually no corrosion for
the t,000 hour samples and while only
preliminary, the results appear the same for the
year-exposed samples. The project is currently
being managed by lERL-Cincinnati.
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Flow Rate
Ultimate Analysis
Heating Value
Chemical Analysis & Trace Elements
Ash Softening Temperature
Emission Rates of Particulate
Filter Paniculate Trace Elements
Impinger Water Trace Elements
Emissions to Atmosphere
I
Coal
Volume Flow
Density
Ultimate Analysis
Heating Value
Chemical Analysis &
Trace Elements
Ash Softening
Temperature
Hopper Ash
(Collected
Fly Ash)
Emission Rates of Paniculate
and Gaseous Species
Particulate Trace Elements
Impinger Water Trace Elements
Particulate Sizing
Flow Rate
Chemical Analysis &
Trace Elements
Ash Softening Temperature
Denotes Sampling Location
Flow Rate
Chemical Analysis &
Trace Elements
Softening Temperature
Figure 7. Boiler Unit Sampling Locations at the Ames, Iowa Solid Waste Recovery Facility.
To complement the completed St. Louis Refuse
Processing Plant Study, sampling and analysis for
selected indicator organisms and viruses,
including potential pathogens, were performed.
The results showed that airborne bacterial levels,
both in-plant and at the property line, are generally
higher for refuse processing plants than for
wastewater treatment plants, refuse collection
vehicles, and a number of other waste handling
facilities that were also tested. Concurrent tests,
however, have shown that these emissions can be
controlled with fabric-filters.
SHWRD has conducted several projects to
develop facility-design data, including alternative
disposal systems and methods for predicting waste
composition and quantity. A study of the Palos
Verde, California landfill involved optimizing
methane production from the landfill and testing
biodegradation processes and rates.
An additional study further defined the state-of-
the-art of methane recovery from landfills and
assessed the technical and economic feasibility of
the concept. The concept is technically feasible.
but economical only under specific circumstances.
Off-site sales of raw (low BTU) gas to industrial
customers is profitable under current market
conditions if a minimum production volume can be
guaranteed. Sales of cleaned gas (medium to high
BTU) to utilities is economical only in specific
cases. With the deregulation of natural gas,
however, this concept will likely be attractive in
most cases. Figure 8 shows the landfill gas
processing facilities in operation at Mountain
View, California.
TECHNOLOGY ASSESSMENTS
In addition to the data being generated from
evaluation of available resource recovery facilities,
studies are being conducted to assess the
feasibility of alternative technologies for resource
recovery.
The biological conversion of cellulosic wastes to
methane is being studied at two commercially
constructed, intermediate-sized digesters. The
results of this techno-economic assessment will
19
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Figure 8. Landfill Gas Recovery Facilities at Mountain View, California.
determine the feasibility of producing methane
from agricultural waste in rural communities.
Research was continued to successfully scale
the laboratory-scale acid hydrolysis process to a 1 -
ton/day continuous pilot plant process. This
process converts cellulose to glucose. The studies
have determined the temperatures, pressures,
acid injection rates, and other factors necessary for
successful conversion of cellulose to glucose on
laboratory scale. Continuing studies are also
optimizing the biochemical process to produce
methane rather than ethyl alcohol from glucose,
since indications are that the methane can be
produced more effectively and lends itself readily
to successful marketing.
Three techniques have been developed and
evaluated on the laboratory scale for utilization and
stabilization of pyrolytic oils produced from
municipal solid waste. Physical and chemical
processing steps are being investigated to
maximize the value of the oils produced and to
maintain their consistency during storage.
Evaluations of the processes are continuing to
select the most promising process for scale-up
studies. The process of choice will be scaled to 50
Ib/day continuous process.
Related studies have identified and verified
chemical treatments for cellulose embrittlement.
As a result, the basic requirements were defined
for producing a fine powdered RDF from the
organic fraction of municipal solid waste.
Another study analyzed 16 small-scale and low-
technology resource recovery systems and
selected seven for further detailed evaluation as
techniques for use by small waste generators.
Based upon study criteria, it was determined that
modular incineration with energy recovery and
source separation were the most feasible and most
promising approaches.
PROCESS EQUIPMENT EVALUATIONS
Several projects are being conducted to evaluate
the operating performance of selected types of
resource recovery process equipment. The
shredders at several large-scale solid waste
processing facilities are being evaluated to
determine their performance characteristics as
well as to verify basic theoretical relationships
developed in laboratory research on the size
reduction of solid waste. The shredder at the
Ames, Iowa Resource Recovery Facility (Figure 9)
is one of the units being tested.
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Figure 9. Shredder at the Ames, Iowa Resource
Recovery Facility.
Figure 10. Interior of the Trommel Screen at
Recovery I.
Another study is evaluating the operating
performance of large-scale air classifiers.
Separate studies are characterizing the froth
filtration process for separating glass and the use
of a trommel to classify the waste prior to
shredding. The use of rotating cylindrical trommel
screens prior to shredding may offer advantages
such as reducing unwanted fines in RDF, reducing
shredder wear, and generally improving the
recovery of materials from solid waste. The interior
of a full-scale trommel is shown in Figure 10.
A more basic research project is investigating
equipment for densifying solid waste to produce d-
RDF. Attempts are being made to develop the basic
data required to design proper equipment and
processes for the production of d-RDF. Studies are
being coordinated with other projects currently
producing d-RDF pellets for combustion tests.
SELECTED WASTES UTILIZATION
Several components of municipal solid waste
have been identified as especially suitable for
recovery and reuse. One component examined in
several applications is discarded automobile tires
and scrap rubber. A study has identified the costs
and benefits of alternative scrap tire management
methods, including use in rubberized asphalt,
retreading, energy recovery through incineration,
and landfilling. Technical parameters are being
assessed; e.g. several rubberized asphalt road
sections receiving everyday use are being
monitored for wear and braking and skid
resistance.
A technical evaluation and market study on
using glass slimes in structural clay brick
manufacturing has involved testing various mixes
of glass in brick to act as a fluxing agent. Glass
slimes are a by-product of glass recovery in
resource recovery operations. They consist of very
fine glass particles(lessthan 150mesh)and mixed
organics amounting to perhaps 20 or 30 percent of
the slime by weight. The study examined the effect
of adding slimes (up to 15 percent by weight) to
bricks as a curing agent. The results have shown
21
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that bricks so made possess equal or superior
quality to conventional bricks and that curing
temperatures can be lowered by 100°F. It appears
that this highly attractive approach offers three
distinct advantages for handling the troublesome
slimes: (1) higher quality bricks and energy savings
in brick manufacture, (2) a market for glass slimes
estimated at $5 to $8/ton FOB the brick plant, and
(3) savings in the $5 to $12/ton disposal cost
normally required to landfill the slimes.
An economic analysis has shown the feasibility
of employing scrap futures markets for ferrous and
waste paper. Establishment of the concept could
aid the trading of these secondary materials and
encourage the flow of capital to the scrap industry.
A related study is examining the relationship
between variable user charges for solid waste
collection and management and the quantity of
solid waste generated as well as the impact of
charges on littering.
ENVIRONMENTAL IMPACT
Several continuing projects involve investiga-
tions of the emission and needed controls to make
resource recovery systems environmentally
acceptable. One study involves emissions from
preprocessing and bioconversion systems. Inves-
tigators are characterizing pollutants, developing
assessment criteria and pollutant measurement
techniques, and performing a trade-off analysis of
costs and performance of pollution control
equipment. Another study will involve selection
and on-site testing of various air pollution control
devices, with a determination of unit acceptability
and needed improvements.
In conjunction with the St. Louis bacteria-virus
study discussed previously, tests were conducted
and determined that fabric filters (i.e. baghouses)
can significantly reduce the high levels of bacteria
in the emissions from the processing plants.
Another study is investigating potential methods
available for removing lead and other metals from
solid waste. The presence of lead in solid waste
has resulted in potentially unacceptable levels of
lead in the emissions from facilities combusting
RDF with coal.
In another study, the impact of resource recovery
on the environment is being assessed. The study
will help to quantify the reduction in
environmental pollution which may result from the
recovery of selected materials.
SPECIAL STUDIES
SHWRD is responding to mandates of RCRA by
conducting several special studies. These studies
are designed to provide status reports to the
Congress on various aspects of resource recovery.
Studies include assessments of selected small-
scale, low-technology resource recovery methods,
evaluation of the compatibility of source
separation with centralized resource recovery
facilities, and techniques for forecasting the
quality and composition of municipal solid waste.
In other special studies, research priorities for
resource recovery are being assessed as are the
impediments to the economical operation of
resource recovery facilities. The status of glass and
plastics resource recovery, and the impediments to
passenger tire recycling are the subjects of other
special studies. These studies are currently
scheduled for completion by October 1979.
REFERENCES
1. Albrecht, O.W., VALUING THE BENEFITS OF RESOURCE CONSERVATION: THE DOMESTIC COPPER
INDUSTRY AS A CASE STUDY, presented at the 107th Annual Meeting of the AIME, Denver,
Colorado, March 2, 1 978.
2. Albrecht, O.W. and Anderson, R.C., VALUING THE BENEFITS OF RESOURCE CONSERVATION: THE
DOMESTIC COPPER INDUSTRY AS A CASE EXAMPLE, in proceedings of Council of Economics,
American Institute of Mining, Metallurgical and Petroleum Engineers, Inc., Denver, Colorado, 1978.
3. Albrecht, O.W., ICC REGULATED RATES - THEIR EFFECT ON TRANSPORTATION OF SECONDARY
MATERIALS, presented at Michigan State Chamber of Commerce Solid Waste Resource Recovery
Meeting, Lansing, Michigan, November 30, 1977.
4. Albrecht, O.W., ICC RATES: SHOULD DISCRIMINATION DEBATE BE SCRAPPED, Waste Age, pp. 88-
92, April 1978.
5. Duft, B.L, Levine, H. and McLeod, A., A STUDY OF THE FEASIBILITY OF UTILIZING SOLID WASTES
FOR BUILDING MATERIALS: PHASE I SUMMARY REPORT, EPA-600/2-78-091, April 1978.
6. Duft, B.L, et al., A STUDY OF THE FEASIBILITY OF UTILIZING SOLID WASTES FOR BUILDING
MATERIALS: PHASE II SUMMARY REPORT, EPA-600/2-78-092, April 1978.
7. Even, J.C., Adams, S.K., Gheresus, P., et al., EVALUATION OF THE AMES SOLID WASTE RECOVERY
SYSTEM: PART I - SUMMARY OF ENVIRONMENTAL EMISSIONS: EQUIPMENT, FACILITIES, AND
ECONOMIC EVALUATIONS, EPA-600/2-77-205, November 1977.
22
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8. Fiscus, D.E., Gorman, P.G., Schrag, M.P. and Shannon, L.J., ST. LOUIS DEMONSTRATION FINAL
REPORT: REFUSE PROCESSING PLANT EQUIPMENT, FACILITIES, AND ENVIRONMENTAL
EVALUATIONS, EPA-600/2-77-155a, September 1977.
9. Gikis, B.J., et al., PRELIMINARY ENVIRONMENTAL ASSESSMENT OF ENERGY CONVERSION
PROCESSES FOR AGRICULTURAL AND FOREST PRODUCT RESIDUES: VOLUME I, EPA-600/7-78-
047, March 1978.
10. Gorman, P.G., et al., ST. LOUIS DEMONSTRATION FINAL REPORT: POWER PLANT EQUIPMENT,
FACILITIES AND ENVIRONMENTAL EVALUATION, EPA-600/2-77-155b, December 1977.
11. James, S.C. and Rhyne, C.W., METHANE PRODUCTION, RECOVERY AND UTILIZATION FROM
LANDFILLS, presented at Institute of Gas Technology's Energy from Biomass and Waste Symposium,
Washington, D.C., August 14-18, 1978. Published in symposium proceedings; also published by EPA
Office of Solid Waste as SW-710, Washington, D.C., August 1978.
12. James, S.C., RECOVERY AND UTILIZATION OF LANDFILL GAS, presented at the 14th Annual
Meeting of the Society of Engineering Science, Bethlehem, Pennsylvania, November 14, 1977.
13. Klee, A.J., Hecht, N.L, Duvall, D.S. and Fox, B.L, CONCEPTS FOR IMPROVING THE FUELFRACTION
OF SHREDDED SOLID WASTE, presented at Fifth National Conference on Energy and the
Environment, Cincinnati, Ohio, November 1-3, 1977.
14. Material Systems Corporation, A STUDY OF THE FEASIBILITY OF UTILIZING SOLID WASTES FOR
BUILDING MATERIALS: PHASE III AND IV SUMMARY REPORTS, EPA-600/2-78-111, May 1978.
15. Tolley, G.S., Hastings, V.S. and Rudzitis, G., ECONOMICS OF MUNICIPAL SOLID WASTE
MANAGEMENT: THE CHICAGO CASE, EPA-600/8-78-013, August 1978.
16. Wiles, C.C., Fiscus, D.E., Olexsey, R.A., et al., EVALUATION OF THE AMES, IOWA REFUSE DERIVED
FUEL RECOVERY SYSTEMS, presented at the Fifth National Conference on Energy and the
Environment, Cincinnati, Ohio, November 1-3, 1977.
17. Wiles, C.C., SUBSTITUTING d-RDF FOR COAL IN AN INDUSTRIAL SPREADER STOKER presented at
the National Waste Processing Conference and Exhibit, ASME, Chicago, May 1978.
18. Wiles, C.C., RESOURCE RECOVERY, presented at the Ames Study, Ames, Iowa, March 15, 1978.
TOXIC AND HAZARDOUS
WASTE TREATMENT
Under the mandates of the Resource 2. Environmental Impacts
Conservation and Recovery Act and the Toxic 3. Treatment Technologies
Substances Control Act, the EPA is in the process TC^uMr» ci^nivirkiuiir* AOCCCCIMCMT
of identifying hazardous and toxic materials TECHIMO-ECONOMIC ASSESSMENT
manufactured or generated by industrial This area involves problem assessment,
operations which, if not properly controlled, pose identifying information and research needs, and
significant environmental and public health the evaluation of new and developing processes. In
problems. Municipal waste disposal facilities are an effort to understand environmental damages
generally not capable of treating and managing already caused, 32 of those pesticides most widely
such materials and their release in certain used in the soil were evaluated for residual toxicity,
instances from unacceptable disposal sites has led degradation mechanisms, and the persistence of
to highly undesjrable environmental any toxic by-products.
contamination. Accordingly, SHWRD's research Also, a study is in progress to determine the
program is concerned with the identification/ nature and amount of industrial hazardous wastes
assessment of effective techniques for treatment that are currently discharged or treated in the
and control of toxic and hazardous waste municipal sector.
materials. Other assessments being performed involve the
These techniques involve biological processes, relevancy and adequacy of existing and developing
incineration, and chemical/physical treatment, as processing techniques for selected hazardous
well as the corresponding economic and wastes. Processes examined include catalysis,
environmental impacts of such activities. The thermal degradation, chlorinolysis, sulphonation,
program is designed to eliminate or reduce the and microwave plasma treatment. Economic
hazardous nature of wastes and to protect the evaluations are analyzing the interrelationships
environment. The research program includes: between control costs and regulations for
1. Techno-economic Assessments hazardous waste treatment and disposal.
23
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ENVIRONMENTAL IMPACT
Pollution levels associated with the processing
of hazardous wastes are being studied to
determine the environmental impacts. One project
is evaluating both toxicity of by-products and the
associated health and environmental hazards of
air emissions from selected hazardous waste
management facilities.
A second project will assess the nature and
magnitude of hazardous pollutants discharged into
the environment from the barrel and drum
reconditioning industry.
TREATMENT TECHNOLOGIES
To effectively process the diverse hazardous
wastes generated, many treatment technologies
have been evaluated.
Thermal Treatment
In an evaluation of combustion (incineration)
techniques, time-temperature relationships were
studied for the control and disposal of large
quantities of Kepone. Under a new investigation,
data are being generated on incinerator design,
efficiency of various air pollution control devices,
and materials handling problems to provide
solutions to difficult waste streams such as PCB's
and organo-metallic compounds.
Microwave plasma detoxification of hazardous
materials shows considerable promise for
eventual use for many organic compounds. To
date, several compounds have been detoxified in
the 5-7 Ib/hr microwave unit (shown in Figure 11).
These include PCB's, PMA, Kepone, Malathion,
and a carcinogenic Navy red dye. During 1979,
plans call for determining if the 5-7 Ib/hr unit can
be used to destroy small lots of hazardous organic
chemicals collected in a region of the country.
Also, a 10-30 Ib/hr unit has been constructed and
is being equipped for trial detoxification studies. It
is anticipated that microwave treatment will prove
to be an effective method for destroying small
quantities of highly hazardous chemicals that
otherwise pose a difficult treatment/disposal
problem.
Biological/Chemical/Physical Treatment
Biological and chemical degradation techniques
for controlling and detoxifying specific hazardous
wastes have been investigated. In an evaluation of
the treatment capabilities of biodegradation as
applied to problematic hazardous wastes, four
sites were investigated to evaluate design and
operational data at facilities successfully treating
organic industrial wastes. Treatment processes
evaluated were (1) conventional air-activated
sludge, (2) anaerobic-aerobic facultative lagoons,
(3) deep shaft oxygen treatment, and (4) pure
oxygen activated sludge. Results from the
engineering, economic comparisons, and
evaluation of treatments revealed that the
facultative lagoon system (Figure 12) is favored
over other biological methods for treatment of
waste organic chemicals.
In evaluating the overall efficiency of pesticide
pits, disposal and rinsing water disposal
techniques, the biodestruction rates for several
compounds and environmental emissions have
been determined. The concrete-lined disposal pit
(Figure 13) has proven, after two years of
investigation, to be an effective, practical and
environmentally safe method for control of dilute
pesticide solutions from agricultural operations.
Plans call for the initiation of a pesticide pit
demonstration program in 1979, in cooperation
with USDA, Soil Conservation Service.
Chemical concentration/conversion of
chlorocarbons and pesticide residue into useful
industrial chemicals has been evaluated as a
means of control. Catalytic decomposition
techniques were also investigated. Specifically,
catalytic hydrogenation of chlorocarbons was
successful, but some reaction products were,
themselves, toxic. The role of catalysts in
controlling hazardous materials has not been
completely determined and additional research is
likely to be required.
Encapsulation techniques have been developed
for the safe storage/disposal of hazardous
materials. Laboratory scale leaching studies of an
encapsulated matrix are completed. Field
verification studies are planned for cementitious
and polymeric encapsulates.
24
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•
Dual Power
Monitor
Flexible
Carrier Gas
Flow Meters
Fan
fLNTmp
1«J of
Figure. 11. Pilot-Scale Microwave Plasma
Detoxification Unit.
25
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pH Adjustment
and Nutrient
Addition
Influent
Aerated Stabilization
Influent Basin
Point #2 /
Anaerobic Lagoon
Equalization
'Basin
Anaerobic Lagoon
Emergency
Spill Basin
Limited Aeration Basin
Incomplete
Facultative
Lagoon
Facultative
Lagoon
Facultative
Lagoon
Office and
Laboratory
Aerated Stabilizaton
Basin
Figure 12. Anaerobic-Aerobic-Facultative Treatment; Schematic Design.
REFERENCES:
1. Albrecht, O.W., A FRAMEWORK FOR ECONOMIC ANALYSIS OF HAZARDOUS WASTES
MANAGEMENT ALTERNATIVES, presented at the 4th Annual Research Symposium on Land
Disposal of Hazardous Waste, San Antonio, Texas, March 6-8, 1978.
2. Albrecht, O.W. and Taylor, Graham, A FRAMEWORK FOR ECONOMIC ANALYSIS OF HAZARDOUS
WASTE MANAGEMENT ALTERNATIVES, presented at 10th Annual Mid-Atlantic Industrial Waste
Conference, Newark, Delaware, June 19-21, 1978.
3. Albrecht, O.W., ECONOMICS ANALYSIS OF HAZARDOUS WASTE MANAGEMENT ALTERNATIVES,
presented at 10th Annual Mid-Atlantic Industrial Waste Conference, Newark, Delaware, June 18-20,
1978.
4. Bailin, L J., MICROWAVE PLASMA DETOXIFICATION PROCESS FOR HAZARDOUS WASTES -
PHASE II: SYSTEMS APPLICATION EVALUATION, EPA-600/2-78-080, June 1978.
5. Bailin, L.J., SUMMARY REPORT - DETOXIFICATION OF NAVY RED DYE BY MICROWAVE PLASMA,
EPA-600/2-78-081, June 1978.
6. Bailin, L.J., Hertzler, B.L and Oberacker, D.A., DEVELOPMENT OF MICROWAVE PLASMA
DETOXIFICATION PROCESS FOR HAZARDOUS WASTES - PART I, Environmental Science and
Technology. Volume 12, No. 6, pp. 673-679, June 1978.
7. Bell, B.A. and Whitmore, F.C., KEPONE INCINERATION TEST PROGRAM, EPA-600/2-78-108, May
1978.
8. Carnes, R.A., OVERVIEWOFTHE KEPONE INCINERATIONTEST,presentationtotheOhioEPAInland
Spills Conference, Dayton, Ohio, October 13, 1977.
26
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Figure 13. Pesticide Disposal Pit at Ames, Iowa.
9. Games, R.A., CHARACTERIZING INPUT TO HAZARDOUS WASTE LANDFILLS, presented at the 4th
Annual Research Symposium on Land Disposal of Hazardous Waste, San Antonio, Texas, March 6-8,
1978. ,
10. Carnes, R.A., CO-INCINERATION OF TOXIC MATERIALS WITH MUNICIPAL SLUDGE, presented at
the 5th National Conference on Acceptable Sludge Disposal Techniques, Orlando, Florida, January
31 - February 2, 1978.
11. Carnes, R.A., Whitmore, F.C. and Stenburg, R.L., KEPONE: AN OVERVIEW, presented at the 4th
Annual Symposium on Land Disposal of Hazardous Waste, San Antonio, Texas, March 6-8, 1978.
12. Carnes, R.A., COMBUSTION CHARACTERISTICS OF HAZARDOUS WASTE STREAMS, presented at
the 71 st Annual Meeting of the Air Pollution Control Association, Houston, Texas, June 25-30,1978.
13. Carnes, R.A., STATE-OF-THE-ART INCINERATION FOR PESTICIDE DISPOSAL, presented at Pesticide
Disposal R&D Symposium, Reston, Virginia, September 6-7, 1978.
14. Duvall, D.S. and Rubey, W.A., LABORATORY EVALUATION OF HIGH-TEMPERATURE DESTRUCTION
OF POLYCHLORINATED BIPHENYLS AND RELATED COMPOUNDS, EPA-600/2-77-228, December
1977.
15. Ebon Research Systems, CATALYTIC HYDRODECHLORINATION OF POLYCHLORINATED
PESTICIDES AND RELATED SUBSTANCES. AN EXECUTIVE SUMMARY, EPA-600/8-77-013,
September 1977.
16. Eichenberger, B., Edwards, J.R., Chen, K.Y. and Stephens, R.D., A CASE STUDY OF HAZARDOUS
WASTE IN CLASS I LANDFILLS, EPA-600/2-78-064, June 1978.
27
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17. Klee, A.J., INCINERATION OF HAZARDOUS WASTES, presented at Pesticide Disposal R&D
Symposium, sponsored by SHWRD/MERL, Reston, Virginia, September 7, 1978.
18. Kown, B.T., Stenzel, R.A., Hepper, J.A., Ruby, J.D. and Milligan, R.T., COST ASSESSMENT FOR THE
EMPLACEMENT OF HAZARDOUS MATERIALS IN A SALT MINE, EPA-600/2-77-215, November
1977.
19. Lubowitz, H.R. and Wiles, C.C., ENCAPSULATION TECHNIQUE FOR CONTROL OF HAZARDOUS
WASTES, proceedings of Fourth Annual Research Symposium - Land Disposal of Hazardous Waste,
EPA-600/9-78-016, San Antonio, Texas, March 6-8, 1978.
20. Oberacker, D.A. and Ase, P.K., AMBIENT AIR EMISSIONS FROM HAZARDOUS WASTE FACILITIES,
Third Symposium on Fugitive Emissions: Measurement and Control, San Francisco, California,
October 23-25, 1978.
21. Oberacker, D.A., SHWRD HAZARDOUS WASTE R&D PROGRAM, presented at Ohio EPA Hazardous
Waste Spills Symposium, September 14-15, 1978.
22. Oberacker, D.A., ENCAPSULATION OF HAZARDOUS WASTES, presented at Pesticide Disposal R&D
Symposium, Reston, Virginia, September 6-7, 1978.
23. Oberacker, D.A., MICROWAVE PLASMA DETOXIFICATION PROCESS FOR HAZARDOUS WASTE
DISPOSAL, Environmental Science & Technology, IMPT Digest, Microwave Power Symposium—
1978, June 28-30, 1978; and Science News, Vol. 13, November 24, 1978.
24. Olexsey, R.A., Wiles, C.C., Joensen, A.W. and Hall, J.L., presented at Fifth National Conference on
Energy and the Environment, Cincinnati, November 1-3, 1977.
25. Rogers, C.J., BIOLOGICAL TECHNIQUES FOR TREATMENT OF PESTICIDES, presented at Pesticide
Disposal R&D Symposium, sponsored by SHWRD/MERL, in Reston, Virginia, September 6-7, 1978.
26. Rogers, C.J., DEVELOPING TECHNOLOGY FOR CONTROLLING PESTICIDES AND OTHER
UNWANTED HAZARDOUS MATERIALS, ASC Symposium Series No. 73,174th Meeting of American
Chemical Society, August 1978.
27. Rogers, C.J., DEVELOPING PRACTICAL METHODS FOR CONTROLLING EXCESS PESTICIDES, Land
Disposal of Hazardous Wastes proceedings of the Fourth Annual Research Symposium, March 6-8,
1978.
28. Rogers, C.J., DEVELOPING METHODS FOR CONTROLLING EXCESS PESTICIDES, presented at the
Fourth Annual Research Symposium on Land Disposal of Hazardous Waste, San Antonio, Texas,
March 6-8, 1978.
29. Sanning, D.E., Johnson, F.C. and Lancione, R.L, STABILIZATION, TESTING AND DISPOSAL OF
ARSENIC CONTAINING WASTES, chapter in a book entitled Toxic and Hazardous Wastes Disposal
Series, published by Ann Arbor Science for the American Chemical Society in cooperation with the
American Chemical Society's International Symposium on The Ultimate Disposal of Hazardous
Wastes to be held April 1-6, 1979 in Honolulu, Hawaii.
30. Schomaker, N.B., DISPOSAL OF HAZARDOUS WASTES, presented at NATO/CCMS Pilot Study
Meeting, Munich, Germany, September 25-28, 1978.
31. Schomaker, N.B., CURRENT RESEARCH ON LAND DISPOSAL OF HAZARDOUS WASTES;
RESEARCH ACTIVITIES OF THE SOLID AND HAZARDOUS WASTE RESEARCH DIVISION: AN
OVERVIEW OF LAND DISPOSAL ACTIVITIES, presented at the 4th Annual Research Symposium on
Land Disposal of Hazardous Waste, San Antonio, Texas, March 6-8, 1978.
32. Schultz, D.W., LAND DISPOSAL OF HAZARDOUS WASTES: PROCEEDINGS OF THE FOURTH
ANNUAL RESEARCH SYMPOSIUM, EPA-600/9-78-016, August 1978.
33. SCS Engineers, DATA BASE FOR STANDARDS/REGULATIONS DEVELOPMENT FOR LAND
DISPOSAL OF FLUE GAS CLEANING SLUDGES, EPA-600/7-77-118, December 1977.
34. Wiles, C.C., ENCAPSULATION TECHNIQUES FOR CONTROL OF HAZARDOUS MATERIALS,
presented at the Fourth Annual Research Symposium on Land Disposal of Hazardous Waste, San
Antonio, Texas, March 6-8, 1978.
35. Wiles, C.C., ASSESSMENT OF DEEP WELL INJECTION OF HAZARDOUS WASTES, presented at the
Fourth Annual Research Symposium on Land Disposal of Hazardous Waste, San Antonio, Texas,
March 6-8, 1978.
28
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WASTEWATER RESEARCH DIVISION
The Wastewater Research Division (WRD) was formed in July of 1975 from the Advanced Waste
Treatment Research Laboratory which had been initiated in Cincinnati in 1960. Advanced waste
treatment work had been carried out under both the U.S. Public Health Service and the Department of the
Interior before the establishment of the U.S. Environmental Protection Agency in 1970. With the passage
of Public Law 92-500 in 1972, with changes in the national perception of municipal research problems,
and with a consolidation of USEPA municipal wastewater pollution research within MERL, the range of
topics expanded beyond those formerly addressed. Wastewater Research Division had become a more
accurate description of the program.
The broad range of technical areas and pollution contTbl approaches being considered by the Division is
reflected in three special topics described herein. The first topic describes some recent pilot plant research
in sludge dewatering, a different engineering problem with grave impact upon waste treatment plant
costs. This work proves that the use of various modes of filter press operation can produce dewatered
sludge suitable for incineration at quite advantageous unit costs, and with annual savings numbering
millions of dollars over alternate methods. The methods described also promise to be useful in retrofitting
existing equipment. The second topic discusses the operation of a promising new biological treatment
method, the deep shaft process. Wastewater flow into and out of a shaft which maybe hundreds of feet (or
meters) deep produces high oxygen levels at the bottom and a high-intensity, high-rate treatment process,
with reduced sludge production. The third topic introduces the concept of treatability of hazardous
compounds, and the need for discovering what factors govern its progress. Studies on treatability can
proceed on two tracks: consideration of the molecular characteristics of the compound; and observation of
removal of specific compounds in bench-scale or pilot plant processes such as adsorption, biodegradation,
and chemical modification.
Following the special topics is a description of the work and of important accomplishments in the
Division.
SPECIAL TOPICS
Improved Dewatering Techniques For
Sewage Sludges
A major factor contributing to the difficulty of
disposing of sewage sludge is the tenacity of its
grip on the water it contains. Sludge typically can
be brought to about 95% water content by
relatively inexpensive processes like thickening.
To remove more water, the sludge must be treated
with coagulating chemicals and vacuum filtered,
centrifuged, or pressed. The commonly used
dewatering devices, vacuum filters and
centrifuges, can produce an 80% moisture content
sludge cake from a mixture of primary and
secondary sludge, still leaving four times as much
water as solids in the product. This excess water
greatly complicates subsequent disposal steps.
Trucking costs to disposal sites are higher because
of the increased amount of water that must be
hauled. If the cake is discharged to a landfill, its
semisolid condition makes operation unsanitary
and dangerous. The landfill fills up prematurely
because of the volume occupied by the water, and
the excessive water load intensifies the problem of
leachate contamination of groundwater from the
landfill in subsequent years. If sludge is to be
incinerated, a disproportionate amount of auxiliary
fuel is needed - as much as 100 gallons of oil per
ton of dry sludge solids.
Devices are now appearing on the market that
produce a drier sludge cake - as low as 55%
moisture. Most of them are so new that operating
experience under a variety of conditions is
inadequate. In order to help Washington, D.C.,
make a proper choice of dewatering equipment for
their Blue Plains' plant, and to provide good
comparative data for the wastewater industry,
EPA's Region III and MERL funded a comparative
study of a variety of dewatering devices designed
to produce a low moisture sludge cake.
The one and a half year study, which began in
1976, was performed by District of Columbia staff
in the EPA-DC pilot plant, using equipment
available in the pilot plant as well as equipment
29
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provided by various manufacturers. The types of
dewatering devices studied were:
1. Vacuum filter
2. Vacuum filter add-on devices
3. Continuous horizontal belt press
4. Recessed plate filter press operated at 100
pounds per square inch pressure
5. Recessed plate filter press operated at 225
pounds per square inch pressure
6. Recessed plate filter press with internal
diaphragm for squeezing additional
moisture from cake
Various combinations of primary and waste
activated sludges were used in comparing
performance of the dewatering devices.
Conditioning agents, eitherferricchlorideandlime
or polymeric conditioning agents, were used to
enhance the filterability of all sludges. The target
for all devices was to produce 65% moisture cake
for a sludge with a 2:1 ratio of waste activated^*)
primary sludge. At this moisture content, sludge
cake can be incinerated with little auxiliary fuel. It
has the structural strength of cardboard, no longer
drips contaminated water, and offers no problems
to landfill operators.
When mixtures of lime and ferric chloride were
used to condition the sludge, filter presses could
dewater sludges containing up to 100% activated
secondary sludge to less than 70% moisture
content. However, similar sludges conditioned
with polymers could not be made to dewater
satisfactorily in a filter press. When the
coagulation effect produced by the conditioning
chemicals was less than optimal, only the
diaphragm filter press could consistently produce a
cake of 65% moisture content. The high pressure
press (225 psig) required 62.3% more filtration
area than the diaphragm press to produce
equivalent results; for the low pressure press (100
psig), 126.8% more area was needed.
With a 2:1 mixture of secondary and primary
sludge, the standard rotary vacuum filter produced
a 78-80% moisture cake. A retrofit unit that
pressed the cake while it was still on the vacuum
filter-surface was capable of decreasing the cake
moisture to only 75 percent. The high pressure
section of a continuous belt press, however,
decreased vacuum filter cake moisture to 65% or
lower.
The continuous belt filter (Figure 14) dewatered
a polymer-conditioned 2:1 mixture of secondary
and primary sludge to produce a cake of less than
70% moisture. However, performance of the belt
filter was not consistent, because sludge
variability resulted occasionally in marginally
conditioned sludges that the unit could not handle.
Poor pressate quality was a problem-about 5% of
the solids escaped capture. The generally good
performance of the belt filter was an important
finding. With a sludge of less variability than the
Blue Plains' sludge, it can provide a low capital cost
solution to sludge dewatering.
Economic analysis of the dewatering devices
showed that on a unit cost basis, for dewatering
only, the belt press ($25.64 per ton dry solids) and
the vacuum filter ($40.25 per ton dry solids)
provide the lowest dewatering costs. Unit costs of
about $54.00 per ton dry solids are nearly the same
for the three types of filter presses. Cost of
incinerating filter press cake is $48.00 per ton dry
solids versus $105.62 per ton dry solids for
vacuum filter cake.
The study offered some interesting conclusions.
First, at Blue Plains the use of filter presses versus
vacuum filters to dewater sludge prior to
incineration will result in annual savings of 4 to 5
million dollars in operating costs. Second, the
diaphragm-type filter press offered the most
flexibility and yielded the best product. Third, the
continuous belt filter press holds considerable
promise as a retrofit device to further dewater cake
from a vacuum filter; continued development of
this technology could provide considerable savings
in capital expenditures. Finally, for a plant that
produces a highly variable undigested sludge or
one with high percentages of waste activated
sludge, the filter press will provide the best
operation in producing a low moisture cake,
generally 65% moisture. For a plant that produces
a relatively consistent stabilized sludge with a
fibrous primary sludge and only small amounts of
waste activated sludge, the continuous belt filter
press should be thoroughly evaluated since cake
moistures of 70% or less can be expected.
In general, the study showed that a cost-
effective dewatering technology is emerging that
is not only capable of producing low moisture
sludge cake, 70% or less, but also offers plants a
promising option of increasing dewatering
capability by retrofitting existing equipment.
Deep Shaft Treatment Of Municipal Wastewater
The development of new wastewater treatment
technology with the potential for significantly
reducing life cycle costs and/or energy
requirements is a long-standing Agency goal
which received renewed support in the 1977
Amendments. One novel biological treatment
approach which shows promise of achieving these
objectives is the Deep Shaft Process. This process
was developed in England by Imperial Chemical
Industries (ICI) as an outgrowth of fermentation
research for single cell protein production. Deep
Shaft Process is now being marketed in North
America by Canadian Industries Limited (CIL), a
wholly-owned subsidiary of ICI.
30
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Figure 14. A "New Generation" Belt Filter, Designed to Produce Sludge Cake of High Solids
Content (Unimate Belt Press, Komline-Sanderson Corporation).
The Deep Shaft Process is an underground
vertical shaft with a downcomer leg and a riser leg
as shown in Figure 15. Raw wastewater and return
activated sludge are introduced continuously to
the top of the downcomer and circulated through
the shaft by the injection of compressed air. To
initiate the process, compressed air is directed to
the riser leg to induce circulation via simple air-lift
principles. Once circulation is established, air
injection is gradually transferred to the
downcomer leg. Circulation is maintained due to
the net difference in total bubble volume (voidage)
between the riser section and the downcomer
section. Since there is no voidage above the
downcomer injection point (normally located at 30-
40% of shaft depth), liquid in the downcomer is
heavier and the greater weight forces flow down
the downcomer and up the riser. The liquid velocity
created is 4-7 times larger than the rise velocity of
the injected air bubbles, carrying them along with
the mixed liquor flow where the combination of
high turbulence (Reynolds Numbers in excess of
100,000) and elevated pressure produce efficient
oxygen dissolution. Functioning in this fashion
with the ingredients of substrate, active biomass,
and dissolved oxygen all present, the shaft
becomes a vertical activated sludge bioreactor.
Shaft size can be tailored to meet varying
hydraulic and organic loading conditions. Shaft
depths from 1 50-1000 ft (45-300 m) are possible
while shaft diameters can vary from 18 in to 18 ft
(0.5-5.0 m). Depending on geologic conditions and
shaft dimensions, conventional drilling or mining
techniques are employed to construct the shaft.
The mining option is normally reserved for large
diameter jobs. When the shaft is drilled, it is lined
with prefabricated steel and grouted with sulfate
resistent cement. The downcomer typically
consists of a smaller concentric pipe in drilled
shafts. For mined shafts, concrete will usually be
specified for the lining with a concrete partition
dividing the shaft into downcomer and riser legs.
31
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Raw
Waste Sludge
Figure 15. Deep Shaft Schematic Diagram.
The increased pressures associated with
increased depths produce a dissolved oxygen
profile which varies from near zero at the top of the
downcomer to 40 mg/l or more at the bottom. As
the mixed liquor travels up the riser, pressure
decreases and dissolved nitrogen, carbon dioxide,
and residual oxygen come out of solution forming
gas bubbles which are released to the atmosphere
in a disengagement head tank surmounted on the
shaft.
The hydraulic mixing regime established in the
shaft results in a high-intensity, high-rate process.
Nominal overall detention time for most municipal
operations will range from 40-80 minutes
depending primarily on the mixed liquor
suspended solids (MLSS) concentration employed.
The high internal circulation rate built into the
design produces a 10-50 - fold dilution of the
influent wastewater and residence times per pass
of only several minutes. Thus, although substrate
removal is patterned after plug flow kinetics during
each pass, the net effect of the rapid circulation
pattern is the operational stability associated with
complete mix activated sludge.
Liquid/solid separation can be accomplished in
two ways. The first utilizes a vacuum degasser to
further effervesce dissolved gases not removed in
the disengagement head tank. A conventional
gravity clarifier follows the degasser. MLSS levels
in this mode are generally restricted to 5,000 mg/l
or less because of the solids loading (flux)
limitations of settling tanks. Settled sludge
typically thickens to about 10,000 mg/l, resulting
in a approximate 100% sludge recycle rate.
The second method takes advantage of the
natural tendency of the mixed liquor leaving the
riser to float. Instead of undergoing degassing, the
mixed liquor is transferred directly from the head
tank to a flotation tank for final liquid/solid
separation. Pilot plant experience in Canada
indicates that, with appropriate polymer addition,
the subnatant routinely meets secondary
treatment standards and is suitable for discharge
without add-on polishing steps. Solids
concentrations in the float vary from 5-10%, thus
obviating the need in most cases for separate
thickening of waste sludge. Without the solids
loading constraints which influence gravity
clarifier operation, MLSS in the flotation mode are
held around 10,000 mg/l, thereby requiring a
sludge recycle rate of only 25% or less. The
bioreactor nominal detention time can thus be
halved while still maintaining the same food-to-
microorganism (F/M) loadings as in the gravity
clarifier mode.
Pilot plant operating and performance data have
been generated at Billingham, England, on
municipal wastewater (96,000 gpd) (363 mVday)
and at Paris, Ontario, on a combined municipal-
textile influent stream (120,000 gpd) (454
mVday). Effluent BOD and suspended solids
concentrations of 15-20 and 20-25 mg/l,
respectively, were observed at volumetric organic
loading rates of 200-260 Ib BOD/day/1000 cu ft
(3.2-4.2 kg BOD/day/m3) of shaft volume. The
Deep Shaft Process is being evaluated in Canada,
the United Kingdom, continental Europe, Japan,
and the United States on a variety of industrial
applications including the treatment of brewery,
dairy, food processing, potato starch, textile, and
chemical waste streams. The first full-scale (30 in
x 500 ft) (0.8 m x 1 52 m) municipal installation is
under construction at Virden, Manitoba. It will
have a capacity of 0.6 mgd (2,270 mVday). No
Deep Shaft municipal construction has yet been
initiated or approved in this country.
To expedite consideration of this novel
technology in the United States, a demonstration
grant was awarded to the City of Ithaca, New York,
in August, 1978. The City will construct and
operate an 18 in. x435 ft(0.5mx 133 m) facility on
the grounds of its existing wastewater treatment
32
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plant as part of its facilities planning investigations
for expansion. Ithaca's treatment plant borders
green belt areas and the city would like to find a
suitable plant expansion method which maximizes
land conservation, one of the principal features of
Deep Shaft. The 30-month project will include 18
months of system operation and data collection.
Total project costs will exceed $750,000 with an
EPA contribution of $500,000.
A dual-purpose clarification unit will be
fabricated which will enable evaluation of both the
flotation and sedimentation modes. Design flows
in these two modes will be 200,000 and 100,000
gpd (757 and 379 mVday), respectively,
corresponding to nominal detention times of 38
and 76 minutes. The F/M loading in both modes is
projected to average approximately 0.75 kg
BOD/day/kg MLVSS under aeration. Volumetric
organic loadings will approximate 350 and 175 Ib
BOD/day/1000 cu ft (5.6 and 2.8 kg
BOD/day/m3) in the flotation and sedimentation
modes, respectively. System start-up following
shaft installation is expected sometime in March
1979. Preliminary performance results should be
available in 10-1 2 months afterthat with final data
accumulation completed in the fall of 1980.
Parameters to be evaluated, in addition to
process performance, will include power
consumption, excess sludge production, and the
economic tradeoff between the larger reactor
volume required in the gravity clarifier mode
versus .polymer requirements in the flotation
mode. Power consumption is tied directly to
oxygen uptake rate and oxygen utilization. Due to
the combination of high intensity mixing and
greatly elevated pressures, oxygen transfer rates
up to 180 lb/1000 cu ft/hr (2,885 kg/mVhr) and
oxygen utilizations of 90 percent or more are
reportedly achieved, yielding an effective power
transfer rate in wastewaterof 4-6 Ib02/hp-hr(2.4-
3.6 kg Ch/kWh). By comparision, conventional air
aeration systems typically achieve 5-15% oxygen
utilization and 1-2 Ib O2/hp-hr (0.6-1.2 kg
02/kWh) power transfer rate. The potential
economic savings in energy are considerable if the
above figures for Deep Shaft power consumption
can be verified.
The unusual cycling environment created by
rapid circulation in the shaft is also credited with
stimulating high microorganism respiration rates
at the expense of cell synthesis. This phenomenon
has led to claims of potential reductions in excess
biological sludge production compared to
conventional activated sludge regimes. Based on
pilot plant experiences to date, it is anticipated full-
scale excess sludge production will approximate
0.5 kg TSS/kg BOD removed at F/M loadings of
0.75-1.0 kg BOD/day/kg MLVSS. Historically,
sludge production at loading rates of this
magnitude would be expected to approach 1.0 kg
TSS/kg BOD removed. Because of the huge capital
and operating costs involved in sludge processing
and disposal, this aspect of Deep Shaft operation
also suggests significant potential economic
savings.
Ttestability Of Hazardous Compounds
Treatability
It is an inescapable truism that rapid progress in
the control of toxics cannot be made unless the
knowledge is obtained on how a compound
behaves in the evnironment or in a particular unit
process of a treatment system. The task is
enormous because of the great number and variety
of compounds and the great diversity of conditions
in an environment or process, but it must be done.
The task can be reduced to manageable
proportions if methods are developed to predict
behavior rather than resorting to experimental
investigation of each compound under each
environmental condition.
Research on how a compound behaves in a
particular environment can take two general
routes. One approach, which can be described as
treatability, makes the assumption that a
compound will behave in a predictable manner
that is characteristic of the compound, as much as
solubility and vapor pressure, etc., are specific for
the compound. Thus, the research considers pure
compounds and progresses from pure solutions to
the more complex solutions represented by
wastewaters and sludges. With enough basic
information on the behavior of the compound and
its molecular characteristics, it may be possible to
develop models which predict the behavior of other
untested compounds. In the investigations of
treatability, a variety of processes must be
addressed such as: adsorption (soils, solids and
carbon), biodegradability (aerobic and anaerobic)
volatility and chemical modification (by oxidation,
precipitation, etc.).
Another approach to this kind of research is to
observe removals of compounds across various
unit processes such as sedimentation, biological
oxidation, carbon contactors, etc. Much can be
learned from this approach about the unit process
but since many mechanisms operate in most
processes, little fundamental knowledge will be
gained about the compound itself. This research
can be characterized as removability.
Because of the need for both short and long term
information, research is taking both approaches of
treatability and removability.
33
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Adsorption On Activated Carbon
One of the potentially useful processes for
control of toxic organic compounds is adsorption
on activated carbon. It has the merit that the
compounds are destroyed when the carbon is
thermally regenerated.
Since adsorption is basically a surface
phenomenon, it follows that substances with very
high surface areas are desirable. Carbon is unique
in that it possesses a very high surface area to
mass ratio. Surface areas of carbons range from ~
600 mVg to > 2000 mVg. Most of the surface
area (95%) is contained in internal surfaces of
pores and capillaries that are developed during
activation of the carbon. An electron microscopic
view of a carbon granule, shown in Figure 16
(provided by Dr. W. J. Weber of the University of
Michigan) shows a rough exterior surface which is
pockmarked by holes which constitute most of the
surface area.
Adsorption is a complex process which involves
both the nature of the carbon surface as well as the
characteristic of the molecule. Some of the latter
factors include solubility, molecular weight,
polarity, ionization, orientation at the surface, and
more. All of these factors contribute to the
adsorbability of a compound which, operationally,
can be determined quantitatively by determining a
batch equilibrium adsorption isotherm, which
mathematically can be described by the equation:
where:
_X
M
Cr
_X - KCf'/n
M
the "loading" of the compound
on the carbon in mg/g of carbon
the amount of compound
remaining in solution after
carbon treatment
K and 1 /n are empirical constants.
The data, when plotted on log-log paper generally
produces linear curves, from which much
information can be inferred by observing the
intercept, K, and the slope 1/n. Some typical
isotherms are illustrated in Figure 17. It can be
seen that adsorption of benzene, because of the
steep slope of the isotherm, shows rapidly
declining adsorption capacity on carbon and low
residual concentrations would be difficult to
achieve. The adsorption isotherms for 0-naphthol
and benzidine are more favorable for adsorption
with the former being adsorbed at higher loadings
on carbon. These isotherms were taken from a list
of some 60 compounds that were collected into a
single publication entitled Carbon Adsorption
Isotherms for Toxic Organics, Municipal
Environmental Research Laboratory, Cincinnati,
Ohio 45268, May 1978.
While carbon is highly effective for the removal
of organics, it is important to point out that the
variation of loading on carbon is great. For
example, the adsorption of 60 compounds
mentioned above varied over 0-360 mg/g of
carbon at an initial concentration of 1 mg/l of
10,000
c
o
t_
CD
O
E1,000
03
.O
100
O)
E
\
x
' B-Naphthol
'" Benzidine
/Benzene
10
0.01 0.1 1.0 10.0
Residual Cone. (Cf), mg/l
100
Figure 16. Electron Microphotograph of a
Carbon Granule.
Figure 17. Carbon Adsorption Isotherms for
Selected Compounds.
34
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compound. Relatively small changes in a molecule
can alter the adsorbability of the compound. This
change in adsorbability is illustrated in Figure 18
which shows the marked effects of substitutions
on a benzene molecule. All adsorption capacities
are given at an initial concentration of compound
of 1 mg/l. Thus, unsubstituted benzene is barely
adsorbable, 0.7 mg/g. Substituting an OH group
for one of the H in the benzene molecule increases
the adsorption by a factor of 30. When Cl is
substituted, this factor increases to 133.
In summary, adsorption (or non-adsorption)
depends on many factors, not the least of which is
the substitution on a parent molecule. It is one of
the goals of the research on treatability to discover
those factors which govern adsorption and
ultimately to be able to predict adsorption in some
systematic way. Without this capability,
laboratories will be burdened with the need to
evaluate adsorption for thousands of compounds.
Compound
Benzene
Phenol
Ethylbenzene
Nitrobenzene
Chlorobenzene
Styrene
Structure Adsorption
Capacity *(mg/g)
r) 0.7
21
H H
©-C-C-H 53
H H
©-CI
*
=C-H
1 -Chloro-2-Nitrobenzene ('JO-NO 2
93
120
130
*Measured at 1 mg/l initial concentration
Figure 18. Adsorption Capacities for Benezene
and Substituted Benezenes.
TECHNOLOGY DEVELOPMENT
SUPPORT BRANCH
OBJECTIVES AND ACCOMPLISHMENTS
The Technology Development Support Branch
provides technical and support services to the
Division. It operates and maintains pilot plants and
provides analytical services to all Division
technology development operations. It is
composed of the Pilot and Field Evaluation Section
and the Waste Identification and Analysis Section.
Pilot and Field Evaluation Section
The Pilot and Field Evaluation Section is
responsible for conducting most of the WRD pilot
plant studies. These are conducted with U.S. EPA
personnel at the Lebanon Pilot Plant and under
contract with the Los Angeles County Sanitation
Districts, Los Angeles County, California. In
addition, personnel of this Section manage the
national program in Instrumentation and
Automation for Wastewater Treatment Systems.
Some of the instrumentation and automation work
is conducted at the pilot plant facilities mentioned
above, but most is implemented through contracts
and grants.
During this year a major activity was
construction of the new Test and Evaluation
Facility (Figure 19) on the groundsof the Mill Creek
Sewage Treatment Plant in Cincinnati, Ohio. This
30,000 square foot facility will be the site of the
major MERL pilot plant activity for many years in
the future. The facility is equipped with all of the
services required for research on water pollution
control. Raw sewage, primary effluent, secondary
effluent, primary sludge, secondary sludge,
digested sludge and heat treatment liquor will be
available on a continuous real time basis at any of
14 stations in the facility. In addition, access on a
controlled basis to the industrial waste tank farm at
this plant has been procured. This will make it
possible to conduct studies on treatment of specific
industrial wastes and on mixtures of industrial
wastes and municipal wastes. The facility is
equipped with a machine shop, dry chemical
storage, wet chemical storage, two wet
laboratories, an instrument laboratory, two cranes,
office space, pure oxygen supply, compressed air
supply, 110V, 220V, and 440V electric power. As
much as possible, instrumentation will be used to
monitor the processes under study. A computer
system will be installed to log data, manipulate
data, plot results, generate reports and implement
process control.
Construction on this facility began in October
1977 and will be complete in January 1979 The
facility should be operating at near full capacity by
July 1979.
35
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Co
Figure 19. The New Test and Evaluation Facility.
-------
The Lebanon pilot plant is scheduled for shut-
down by January 1979. Thus, during the last year
studies underway at this facility have been brought
to a conclusion. One of these studies was an
evaluation of the feasibility of joint treatment of
septage and sludges generated at biological
treatment plants. Long-term daily feed studies of
anaerobic digestion of mixtures of septages and
conventional sludge were conducted. Detention
times ranging from 10 to 30 days were used with
mixtures ranging from 0% septage to 100%
septage. It was found that the presence of septage
had no effect on the performance of the anaerobic
digestion systems. Thus, it is feasible to treat
septage by anaerobic digestion along with
conventional sludge. Companion studies of
treatment of mixtures of septage and conventional
sludge with aerobic digestion are still being
conducted. The septage has not interferred with
the biological stabilization of the septage and
sludge. However, intense foaming often takes
place in the units fed septage. If the air supply is
reduced to control foaming, the system becomes
anaerobic and results in decreased degradation of
organics.
Among the other studies underway at Lebanon
are the effect of activated carbon on anaerobic
digestion, the effect of nitrate on activated carbon
performance, and attempts to verify and then use
mathematical models of anaerobic digestion to
control that process.
At the Joint Water Pollution Control Plant in Los
Angeles County, two major studies are underway
or were completed. A study of a sludge stabilization
system employing heat treatment and anaerobic
digestion indicated that heat treatment slightly
increases the quantity of methane which can be
produced during anaerobic digestion. However,
anaerobic digestion after heattreatment negates a
portion of the increase in sludge dewaterability
resulting from heat treatment. The liquor from heat
treatment could be easily treated in an anaerobic
contact filter.
Successful composting of digested sludge
dewatered in a solid b,owl centrifuge by the open-
air window method was previously achieved at this
plant. However, when the cake from a second
stage basket centrifuge was added, composting
was poor because the second stage cake has a
higher moisture content. Various attempts to
overcome this including the use of bulking agents,
artificial aeration, etc., were not successful. The
study will continue in an attempt to resolve the
problem.
Instrumentation and Automation Program
A major activity of the Instrumentation and
Automation program was the demonstration of
automated analysis and control of the solids
handling processes. As a part of this program, a
control strategy is now being developed for the
vacuum filter (Figure 20). This strategy
encompasses automatic control of the following
parameters.
0 ferric chloride feed flow control
0 lime feed flow control
0 drum speed control
0 vat level control
The tests conducted to date have all been short
term tests designed to assess the control
characteristics of the process. However, these
preliminary tests have indicated that a 40%
reduction in lime dose from the dose of the
previously used manual control system may be
achieved.
Also, automation of sludge thickening was
implemented as a part of this program. It was found
that the improved control of sludge blanket level,
obtained with the automatic control strategy,
substantially reduced the mass of suspended
solids returned to the primary sedimentation
tanks. When compared to the current manual
control system, the treatment cost savings
obtained from the increased solids capture
efficiency were found to be substantial.
A design handbook for the automation of
activated sludge treatment plants is being
developed for the use of sanitary engineers.
Included in the handbook will be a primer on
automatic control techniques, and a state of the art
report on automated control strategies now in use
at nine activated sludge treatment plants. The
handbook will supply full documentation of the
instrumentation used in implementing each of the
control strategies studied. This documentation will
contain the following information:
0 equipment specifications
0 equipment maintenance requirements
0 system reliability
° system cost effectiveness
The handbook is intended to provide the sanitary
engineer with guidelines for designing, procuring,
and implementing automated control strategies in
an activated sludge wastewater treatment plant.
An evaluation of control strategy and
management information system performance
will be undertaken at the Central Contra Costa
Advanced Water Reclamation Plant. The new
facility includes lime coagulation of raw sewage,
single stage biological nitrification and sludge
incineration with lime recovery. Automation will
be implemented by direct digital control.
Automated control strategies will be evaluated by
comparing their performance and costs to the
performance and costs of manual plant operation.
Using the digital computer, a plant management
37
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Primary
From Thickener
Concentration
Tanks
•to Filter #1 Through #8 (F & I No. 1)
-RR)-~(SC)
Chemicals
From Thickener
#2, 4, 6
Holding Tank
No. 2
Filtrate to Primary Tank
—- To Filter #15 through #20
Figure 20. Schematic of Vacuum Filtration Control System.
information system will be implemented which
will include such information as operational data
logging, regulatory agency report generation,
maintenance repair information in preventative
maintenance scheduling, cost analysis, etc. The
utility of the management information system will
also be determined.
The U.S. EPA and the National Bureau of
Standards entered into a cooperative venture to
develop specifications for wastewater treatment
plant process instrumentation. The specifications
will include acceptance standards, installation
standards, and standard calibration methods.
A separate study is being conducted to
determine the feasibility of establishing an
independent instrumentation test laboratory. The
SIRA laboratory in the U.K. has offered their
assistance and maybe used as a model for the U.S.
laboratory.
Waste Identification and Analysis Section
Analytical Support
An important duty of this section is to provide
accurate analyses of a wide variety of poll utants for
all of WRD. Modern computerized equipment is
used to handle a large sample load. Analyses
include heavy metals, algal nutrients, total and
suspended solids and gross organics in
wastewaters and sludges. This analytical service
also included extensive metals analyses for the
Technical Support Division of Water and
Hazardous Materials Office in their 1,000-city
national water survey.
The Section also provides analytical procedures
development as required to support the analytical
needs of WRD. With the recent concern for the
presence of toxic substances, especially organics
in the wastewaters and sludges, the Section in the
past year began to expand its capabilities to supply
analyses of municipal wastewaters and sludges
for specific toxic organics using GC, GC/MS, and
liquid chromatographic techniques. Procedures for
the analyses of the EPA Consent Decree toxic
organics in municipal sludges did not exist and the
state-of-the-art EPA EMSL Guidelines for these
analyses in municipal raw wastewater required
verification. These deficiencies in analytical
capabilities created both a WRD and a national
need on analytical development for analyses of
toxic organics in municipal wastewaters and
sludges.
To meet this need, the Section provided the lead
role in a most urgent intramural-extramural
project, i.e., the development of analytical
procedures for priority organics in municipal raw
wastewaters and sludges. These procedures were
needed not only by WRD but by the EPA Office of
Water Planning and Standards so that they could
initiate a national survey of municipal
wastewaters and sludges for the toxic priority
pollutants.
38
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A preliminary evaluation of the EPA EMSL
Guidelines, Sampling and Analysis Procedures for
Screening of Industrial Effluents for Priority
Pollutants, as applied to municipal raw
wastewater, was performed by the intramural
teams of WRD and the Athens Laboratory, with
support from Cincinnati EMSL. These guidelines
featured a procedure for purgeable organics, a
procedure for pesticides and PCB's and a
procedure for base/neutral and acid extractable
organics. Additional work on the evaluation of the
EMSL Guidelines was performed by WRD and A.D.
Little, Inc. Two, prototype, transportable,
automatic composite samplers (previously
developed by WRD) were also constructed for field
evaluation on raw municipal wastewater for
obtaining purgeable organics samples. These
evaluations confirmed the general applicability of
the EMSL guidelines for analyses of municipal raw
wastewaters for priority (EPA Consent Decree)
organics.
Development of Procedures for Municipal Sludges
The development of analytical procedures for
determination of organics in municipal sludges
was performed using sludges typically
respresentative of those available at conventional
wastewater treatment plants. These sludge
samples were: thickened, combined, raw, primary-
secondary sludge, and the discharge of
anaerobically digested sludge from the digester.
The sludges chosen usually contained about 5%
solids by weight. A modest amount of work was
also performed using waste activated sludge and
primary sludge separately.
The overall technical approach for analyses of
municipal sludges evolved into two basic
alternatives. The first alternative paralleled and
modified the approach used in the EMSL
guidelines for analysis of industrial wastewaters.
The second sludge approach employed extractive
steam distillation as a substitute for the
liquid/liquid extraction of the base/neutral and
acid extractable organics in the first alternative.
These approaches used extensive clean-up
procedures including gel permeation
chromatography and/or silica gel chromatography
to prepare the extracted organics for GC/MS
analyses. They also featured the use of methylene
chloride or methylene chloride/methanol solvent
systems in the clean-up procedures. These solvent
systems provided low boiling evaporation steps to
minimize losses of the organics during evaporative
solute concentration before the GC/MS
identification and quantitation.
The overall project has produced preliminary
procedures which are being further evaluated by
the intramural-extramural team. They will serve as
a bases for developing an EMSL Guideline for the
Analyses of Priority Organics in Municipal
Sludges. The EMSL Guidelines are scheduled for
delivery by October 31, 1978, although additional
verification work will continue through December
1978.
REFERENCES
1. Austern, B.M., Pressley, T.A., and Winslow, L.A., APPARATUS FOR CONTROL OF FOAMING, ADC
Newsletter, 35, 6, October 1977.
2. Bishop, D.F., Heidman, J.A., Brenner, R.C., and Stamberg, J.B., ALUM ADDITION AND STEP FEED
STUDIES IN OXYGEN ACTIVATED SLUDGE, EPA-600/2-77-166, September 1977.
3. Cummins, M.D., DATA ACQUISITION, STORAGE AND ANALYSIS SYSTEM FOR STUDIES OF
ANAEROBIC DIGESTION CONTROL STRATEGIES, presented at EPA-ORD-ADP Workshop, Athens,
GA, May 1978.
4. Molvar, A.J., Roesler, J.F., Wise, R.H., and Babcock, R.H., HOW RELIABLE IS INSTRUMENTATION IN
WASTEWATER APPLICATIONS?, Instruments and Control Systems. 50, 29, October 1977.
5. Oppelt, E.T., Smith, J.M., and Feige, W., EXPANDED BED BIOLOGICAL TREATMENT, EPA-600/2-78-
117, July 1978.
6. Roesler, J.F. and Cummins, M.D., ANNUAL REVIEW OF THE LITERATURE IN INSTRUMENTATION
AND AUTOMATION OF WASTEWATER COLLECTION AND TREATMENT SYSTEMS, JWPCF, 50,
1185, 1978.
7. Roesler, J.F. et al., A COST BENEFIT ANALYSIS FOR AUTOMATION OF WASTEWATER TREATMENT
PLANTS, Progress in Water Technology, 9, 369, 1978.
8. Warner, H.P. and English, J.N., WASTEWATER TREATMENT FOR REUSE AND ITS CONTRIBUTION
TO WATER SUPPLIES, EPA-600/2-78-027, March 1978.
9. Wise, R.H., Pressley, T.A., and Austern, B.M., PARTIAL CHARACTERIZATION OF CHLORINATED
ORGANICS IN SUPERCHLORINATED SEPTAGES AND MIXED SLUDGES, EPA-600/2-78-020,
March 1978.
39
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10. Yarrington, R., Schuk, W.W., Bishop, D.F., et al., DIGITAL COMPUTER CONTROL OF ADVANCED
WASTE TREATMENT SYSTEMS, EPA-600/2-77-211, November 1977.
11. Chen, C.L. and Miele, R.P., DEMORALIZATION OF CARBON-TREATED SECONDARY EFFLUENT BY
SPIRAL-WOUND REVERSE OSMOSIS PROCESS, EPA-600/2-78-169, September 1978.
12. Chen, C.L. and Miele, R.P., WASTEWATER DEMORALIZATION BY CONTINUOUS COUNTER
CURRENT ION EXCHANGE PROCESS, EPA-600/2-77-1 52, September 1977.
13. Chen, C.L. and Miele, R.P., WASTEWATER DEMORALIZATION BY TUBULAR REVERSE OSMOSIS
PROCESS, EPA-600/2-78-167, September 1978.
14. Chen, C.L. and Miele, R.P., WASTEWATER DEMORALIZATION BY TWO STAGE FIXED BED ION
EXCHANGE PROCESS, EPA-600/2-77-148, September 1977.
15. Directo, L.S., Chen, C.L and Miele, R.P., TWO STAGE GRANULAR ACTIVATED CARBON
TREATMENT, EPA-600/2-78-170, September 1978.
16. Levitt and Sons, ADVANCED WASTE TREATMENT FOR HOUSING AND COMMUNITY
DEVELOPMENTS, EPA-600/2-78-168, September 1978.
17. Ortman, C., Laib, T., and Zickefoose, C.S., TOC, ATP AND RESPIRATION RATE AS CONTROL
PARAMETERS FOR ACTIVATED SLUDGE PROCESS, EPA-600/2-77-142, September 1977.
18. Petrasek, A.C., WASTEWATER CHARACTERIZATION AND PROCESS RELIABILITY FOR POTABLE
WASTEWATER RECLAMATION, EPA-600/2-77-210, November 1977.
SYSTEMS AND ENGINEERING
EVALUATION BRANCH
Objectives and Accomplishments
The Systems and Engineering Evaluation
Branch is composed of the Urban Systems
Management Section, the Storm and Combined
Sewer Section, and the Systems and Economic
Analysis Section. Its programs include the study of
methods for improving the operation of publicly
owned treatment works and for developing
approaches to controlling urban wet weather
discharges. The Branch is also responsible for
providing design methods for rural, institutional
and individual home systems and for conducting a
program for water conservation and wastewater
reuse.
Urban Systems Management Section
Operation and Maintenance
The operation and maintenance (O&M) program
has experienced an expansion of program scope
and diversity during 1978. Significant progress
has been made relative to the program's mission of
development and demonstration of methods,
processes and procedures for improved operation
and maintenance, effluent performance, and
reliability of municipal wastewater treatment
plants.
The most significant result of the O&M program
has been the completion of the second phase of the
National O&M Cause and Effect Survey. This
survey has provided State and Federal
Government policy makers and researchers with
the comprehensive data base necessary to
formulate and implement effective municipal
treatment works corrective O&M programs.
Highlights of the survey include the demonstrated
cost effectiveness and success in the application of
a Composite Correction Program (CCP) to improve
plant performance. This program recognizes the
many factors that normally cause poor
performance at a given facility and that an effective
corrective program must address all of them. The
study showed that application of this on-site
corrective program could bring over 70% of non-
complying plants into compliance at a fraction of
the cost necessary for alternative upgrading
approaches. Because of the success of the above
approach, the O&M program is progressing
towards implementing the CCP on a region-wide or
state-wide basis in an effort to further document
and project the cost/benefits of CCP nationally.
The top ten causative factors determined from
the national survey can be broken down and
broadly classified as operator training and facility
design problems. From the assessment of the
operator training problems, the O&M program will
fund a project, in conjunction with other EPA
training groups, to evaluate the effectiveness of
on—site operator training programs. This project
will deal with developing methodologies for
evaluating effectiveness of operator training
programs and define the cost/benefits of on-site
training programs.
Design related causative factors will also be
emphasized by the O&M program over the next
two years. Many of the design deficiencies
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determined from the survey and other sources will
be summarized on a design deficiency checklist to
be developed by the USMS O&M staff for
immediate use by the Regional Construction
Grants staff. This matrix will also be used to
establish priorities in a project to develop low-cost
corrections to the design deficiencies listed.
A specific high priority design program related to
secondary clarifiers was identified in the National
Survey. In response, the O&M program has
implemented a group of separate projects which
will evaluate and document improvements to
secondary clarifier performance through
demonstrated improvements in hydraulic
efficiencies. All major types of secondary clarifiers
will be evaluated through use of fluorometric dye
tracer techniques. These fluorometric techniques
will be used to quantify the hydraulic
characteristics of full scale secondary clarifiers
and propose modifications to improve these
hydraulic characteristics. After modification,
clarifier hydraulic characteristics will be
flurometrically measured and the impact on
effluent quality determined. The final output from
this program will be definitive clarifier design
guidelines which will emphasize the optimization
of clarifier hydraulics.
The wide diversity of the O&M program can also
be seen in some of its major accomplishments
during 1978. In response to the O&M program's
desire to evaluate processes with high levels of
performance and reliability, a project was
completed which examined the performance,
reliability, and total cost aspects of oxidation ditch
plants along with competing biological processes.
The final report from this project provided basic
design information for oxidation ditch plants
including anticipated effluent performance and
reliability. Typical O&M costs and problems were
presented along with the processes' potential for
nitrification and nitrogen removal. All of the
information was compared to other competing
conventional biological processes. The report
found the oxidation ditch process to have a higher
level of performance and reliability at a lower cost
than other competing biological processes in the 1 -
10 MGD range. The final report has generated
substantial interest requiring a second printing. A
newsletter synopsizing the results is also in
preparation which will be widely distributed to the
engineering community.
A report was also completed which investigated
novel methods and materials of construction for
wastewater treatment plants. The emphasis of the
report was to determine if the construction cost of
municipal treatment plants could be reduced
through introduction and use of novel methods and
materials of construction. These included
nonstructural factors (administrative procedures,
regulatory and technical policies, constraints, etc.)
as well as structural factors (construction
practices, methods, and materials). Based upon
potential for capital and construction cost savings
and implementation feasibility, 16 nonstructural
solutions were proposed and rated. For
unconventional methods and materials of
construction, nine potentially cost effective
concepts were identified: in situ pipe liners,
trenchless sewer pipe installation, sewer-within-
sewers, greater use of fiberglass reinforced plastic
(FRP) products including piping, bridges, plastic
hydraulic control equipment, miscellaneous
digester covers, covers and enclosures, and
miscellaneous items. Concepts identified as novel
and feasible from the standpoint of engineering,
advantages and cost savings were shipboard
treatment, drilled vertical shaft construction,
reinforced earth tanks, precast concrete tanks and
reinforced asphalt pond liners.
The O&M program's four-project reliability,
engineering and analysis program is progressing
toward its goal of developing overall plant
reliability design guidelines. Analysis of the
reliability of biological processes has continued at
the University of California/Davis. Analysis of.
performance data from 37 activated sludge plants
has resulted in a reliability model which can
accurately predict the level of performance for
which an activated sludge plant must be designed
to meet a specific level of reliability. A similar
model is in preparation for attached growth
systems. Basic research is continuing on the
development of a new biological stability/
reliability model. It is anticipated that the final
model from this project will be capable of
predicting the performance and reliability of
biological processes from various design,
operational and environmental factors including
the impact of toxic materials.
Other phases of the reliability, engineering and
analysis program have continued during 1 978. A
contract has been negotiated with Southwest
Research Institute to evaluate and document the
reliability of conventional treatment plant
components. This project will collect and analyze
failure rate data for various generic
type/application groupings of mechanical
components. This information will be used in
conjunction with the other reliability projects
outputs in the development of overall plant
reliability design guidelines. These guidelines will
present data and methodology which will give
design engineers the ability to design treatment
processes for specific levels of reliability and
perform cost/reliability analyses for various
processes.
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The O&M program is continuing its work in the
optimization of operation and maintenance of
treatment plants. Centralized management of the
operation and maintenance of groups of small
treatment plants represents a substantial potential
O&M cost savings. A simulation model being
developed with in-house staff capabilities will
predict costs associated with several management
alternatives for O&M of a group of plants. These
alternatives would range from independent
operation to circuit rider operation assisted by low-
level monitoring and telemetry. Data for
development and refinement of the simulation
model is being collected under separate grants
with Gulf Coast Waste Disposal Authority in
Houston, Texas and Cuyahoga County Sanitary
Engineering Department in Cleveland, Ohio.
Completion of the centralized management
program will include a regional demonstration of
the least cost management alternatives as
determined by the simulation model.
The O&M computerized data base initiated in
support of the National O&M Cause and Effect
Survey and other O&M initiatives will be
operational in 1978. The data base will provide in-
house capabilities for the analysis of a wide variety
of design, operational, and geographical factors
and how they impact plant O&M cost, performance
and reliability. With all the programs operational,
the computerized data base will allow ORD,
Headquarters, and Regional people broad access
to a reliable data base to answer a wide variety of
questions relative to O&M costs, design, and
performance capabilities of wastewater treatment
systems.
Municipal Wastewater Reuse
The objectives of the reuse program are the
implementation of research that proves the
feasibility of: (1) the near term, less controversial,
nonpotable use of wastewater to extend valuable
water supplies by source substitution; and (2) the
longer term, or possible emergency use of
wastewater for potable purposes. The Wastewater
Research Division is supporting projects in both of
these areas and is coordinating its activities
through a cooperative agreement with the
American Water Works Research Foundation
(AWWARF) and with other concerned Federal,
state, and municipal organizations engaged in
similar research. Periodic newsletters and reuse
reports are prepared by AWWARF and distributed
among participating organizations as a means of
information exchange.
To assist implementation of wastewater reuse
for nonpotable purposes, a wastewater reuse
guidance manual is being developed. This manual
is directed toward water managers and resource
planners and is intended to make the user aware of
proven reuse possibilities that may exist nearby,
and to alert the user to EPA's support and
encouragement for the reuse approach. Following
the step-by-step plan provided in the manual, the
water manager and resource planner will be able
to address the principal areas of concern
encountered in developing sound water reuse
programs, including technical constraints, water
quality criteria, economics and financing, legal
issues and institutional arrangements, long-term
program dependability, marketing the resource,
public information, and steps toward
implementation.
Because the quantity and quality of municipal
wastewater can be affected by water conservation
programs implemented by water utilities, data
collected from wastewater treatment facilities
operating during the 1976 and 1977 drought
conditions in the western United States, when
water conservation was instituted as the most
efficient means of reducing water demand, are
being analyzed to determine the impacts on
sewers and the ability of treatment plants to meet
discharge and reuse quality requirements with
more concentrated influents. Because of these
concerns, data are needed to make
recommendations for a policy and follow-on action
if water conservation is to be advocated on a
continuing basis.
Recognizing the potential benefits of the
planned reuse of wastewater for domestic
purposes, and recognizing health questions
associated with the already existing unplanned
reuse of wastewaters such as occurs in
communities throughout the U.S. which have
water intakes downstream of waste discharges,
the U.S. Congress included in Section 1444(a)(2) of
PL 93-523, the Safe Drinking Water Act,
authorization to establish a program to
demonstrate the reuse of wastewater for drinking
purposes. In addition. Section 5 of PL 95-155, the
EPA Research and Development Authorization Act
of 1978, re-emphasizes Congress's interest in
establishing a potable reuse demonstration
program. The initiation of this program is a major
new responsibility of the Wastewater Research
Division.
Data is being collected on the extent of
unplanned reuse for potable purposes in a project
to determine the percentage of wastewater in
water supplies of U.S. cities with a population of
25,000 or more. Five hundred and eight water
supply utilities and 23,103 upstream wastewater
discharges have been identified and efforts are in
progress to utilize data on water utilities, stream
flows and wastewater discharges to make
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computations of the percent wastewater in each
utility intake.
Small Flows
Implementation of the Clean Water Act
Amendments of 1977 (PL 95-217) has directed
considerable attention to the continuing efforts of
the Small Flows Research Program. For the first
time since the inception of the EPA Construction
Grants Program, individual on-site treatment
works, such as septic tank - soil absorption
systems, are eligible for federal grants if a public
entity applies on behalf of these individual units
and assures EPA that these systems are properly
operated and maintained. The Act specifically
requires that, for states having a rural population
of 25% or more of the total, 4% of that state's
allotted funds must be utilized only for alternatives
to conventional sewage treatment works for
municipalities which are considered to be highly
dispersed in population. Such alternatives include,
but are not limited to, septic tank - soil absorption
fields, individual mount systems, evapotranspir-
ation beds, self-contained toilets, soil disposal or
other systems serving clusters of homes, and
alternative sewage collection techniques such as
pressure and vacuum sewers. Small communities
are the primary targets for implementation of these
alternatives due to the often prohibitive cost of
providing conventional gravity sewers and
centralized sewage treatment facilities.
The impact of the 1977 Clean Water Act on
program activities has been: reassessment of
research priorities and objectives to meet the
immediate needs of engineers, planners, and
regulatory authorities; providing technical
assistance to a diverse array of people involved
with small scale technologies for wastewater
treatment and disposal; continuing a series of five
Technology Transfer design seminars across the
country on rural wastewater treatment
alternatives; and implementing two intensive one-
week training sessions in Cincinnati and Denver to
assist federal and state engineers in the review of
facilities plans which employ small-scale or on-
site wastewater treatment technology.
The Small Flows Research Program is divided
into four main areas of study. These include (1)
individual on-site wastewater treatment and
disposal technology, (2) management of residuals
generated from on-site systems, such as septic
tank pumpings (septage), (3) alternative
wastewater collection techniques, such as
pressure and vacuum sewers and small diameter
gravity sewers for septic tank effluent, and (4)
institutional arrangements to ensure proper
management of individual systems. The common
objective which links these various efforts is the
provision of adequate protection of public health at
a reasonable cost.
Much of the work supported by EPA dealing with
on-site treatment systems has recently culminated
in the form of a 900-page final report prepared by
the University of Wisconsin. This report represents
some five years of research effort, and covers
many aspects of on-site wastewater treatment
systems - their application, costs, theory of
operation, design, construction, and management.
A continuing EPA grant to the University of
Wisconsin is supporting more research into
refining construction techniques, rehabilitating
failed soil absorption systems, developing methods
to improve their performance, and generating data
on the treatability of graywater (non-toilet
wastewater). A report from the University of
Colorado dealing with evapotranspiration beds and
mechanical evaporative disposal techniques will
be published in the near future. Two new grants
have recently been initiated with the states of
California and Oregon. These demonstration
grants are both designed to collect data from a
diverse number of existing on-site treatment
systems. The California project will also address
the public health aspects of alternative
blackwater-graywater systems which have been
installed in that state, while the Oregon project
seeks to analyze the performance of a wider variety
of on-site alternative systems.
Studies of septage handling are continuing
through the University of Lowell in Massachusetts.
The primary objectives of this study are to
determine the impacts of treating septage at a
sewage treatment plant, determine how to assess
the capacity of a plant to handle this waste, and to
investigate other techniques for treating septage
at a sewage treatment plant. A report is also being
published which summarizes research performed
in Maine dealing with alternative septage
treatment techniques. A cooperative study
between EPA and the National Park Service is
investigating composting of wastes pumped from
portable toilets and septic tanks.
State-of-the-art reports on pressure and
vacuum sewers have been developed, and
numerous demonstration projects have been
completed that deal with these technologies.
Recently, a project was completed that was
designed to collect data on cost, performance,
operation and maintenance requirements, and
type of treatment provided for a number of
pressure sewer installations in operation across
the country. Another project which evaluated
small pressure and vacuum sewers in a single city
has also been completed, and the report published.
Since the 1977 Clean Water Act stipulates the
requirement of a "management district" or other
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public body to allow individual systems to be grant
eligible, there has been much concern over what
forms such an entity might take, how one would be
implemented, what the functions of a
management district would be, and other legal and
institutional questions. In response, the Small
Flows Research Program has initiated a
comprehensive research contract which will
include detailed case studies of existing on-site
management practices and policies at the local and
state levels. An analysis will be made of the
appropriateness, effectiveness, and costs of
alternative management approaches under
different local situations. Recommendations will
be outlined for selection and implementation of
management structures and techniques.
For future years, it is anticipated that, while
basic research will continue to be supported, more
emphasis will be placed upon demonstrating to the
public that many of the low-technology,
decentralized alternatives are viable, cost-
effective approaches to ensuring environmentally
sound waste management practices for rural and
suburban communities.
Storm and Combined Sewer Section
Control and/or treatment of storm sewer
discharges and combined sewer overf lows (CSO's)
are major problems in the field of water quality
management. Every time it rains, in the majority of
the oldest and largest cities, tremendous volumes
of mixed pollution laden urban runoff and raw
sewage (CSO) spill into and contaminate receiving
waters. Another problem area during wet weather
exists due to man's land development activities
which have initiated severe, highly undesirable,
and damaging alterations in the natural
sedimentation cycle, particularly in local areas, by
drastically accelerating the erosion-sedimentation
process. Over the past decade much research
effort has been expended and a large amount of
information has been generated, primarily through
the Storm and Combined Sewer Section.
Storm and Combined Sewer research and
development effort has been directed to the
abatement of pollution loads from CSO. The
technology that has been developed for CSO
control in many cases has almost direct and
complete application for the control of urban
stormwater from separate storm drainage systems
as well as aspects of sedimentation control.
There has been increased realization that, along
with technology develoment, there is a need to
better define the actual effects of wet-weather
discharges on receiving waters. Results from work
in this area are currently being evaluated. Also,
because of the high capital cost of treatment
methods, there is an increased effort being
undertaken to consider other approaches that have
much lower capital cost. These include
management practices such as improved street
sweeping and flushing of sewers during dry
weather to reduce the amount of sediment that
would otherwise be removed by the next storm and
the use of more effective erosion and
sedimentation control techniques.
Treatment and Control
Due to adverse and intense flow conditions and
unpredictable shock loading effects, it has been
difficult to adapt existing treatment methods to
storm-generated overflows, especially the
microorganism-dependent biological processes.
The newer physical/chemical treatment
techniques have shown more promise in
overcoming these adversities. To reduce capital
investments, projects have been directed towards
high-rate operations approaching maximum
loading boundaries by using the swirl,
microstrainer, high rate filter, and dissolved air
flotation. These processes, or combinations of
these processes, can be adjunct to the existing
sanitary plant or serve as remote satellite facilities
at the outfall.
At Lancaster, Pennsylvania, as shown in Figure
21, construction has been completed on a 24 ft.
diameter swirl CSO regulator/solids separator
with a smaller 8 ft. diameter swirl degritter in
series to degrit the swirl regulator underflow prior
to its entry to the interceptor pumping and sewer
system. The swirl system will serve a drainage
area of 135 acres.
At the treatment design flow of 25.8 mgd which
represents a six in one year storm frequency, 65
percent suspended solids removal is estimated.
The device iscapableof functioning efficiently over
a wide range of combined sewer overflow rates
Figure 21. Swirl Regulator/Solids Separator at
Lancaster, Pennsylvania.
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and can effectively separate suspended matter at a
small fraction of the detention time required for
sedimentation.
A helical type regulator-separator has also been
developed based on principles similar to those of
the swirl. The helical is beneficial because of its
low depth and because its separation action is
created by merely an enlarged bend in the sewer
line. Construction of a full scale swirl and helical
regulator, to be used in a comparison study, was
completed this year near Boston, Massachusetts.
Post-construction evaluation is now underway.
Other physical processes with or without
chemicals, such as fine screens, high-rate filters,
sedimentation, and dissolved air flotation, have
been developed and demonstrated in the program.
Source Control and Low Structural Cost
Approaches
Nonstructural and low structurally intensive
alternatives, termed best management practices
(BMPs), offer considerable promise as the first line
of action to control urban runoff pollution. By
treating the problem at its source, or through
appropriate legislation curtailing its opportunity to
develop, multiple benefits can be derived. These
include lower cost, earlier results, and an improved
and cleaner neighborhood environment.
The greatest difficulty faced by BMPs is that the
action-impact relationship is almost totally
unquantified. It is clear that onsite storage, for
example, can be closely related to reduced
downstream conduit requirements but the net
water quality benefits are far less defined.
Similarly, cleaner streets and neighborhoods and
enforced legislation will eradicate gross pollution
sources but to what limit should they be applied
and who will bear the cost? The final answers of
cost effectiveness will not be found short of trial
implementation. Key demonstration projects in
this regard have been awarded this year. At
Belleview, Washington, and Orlando, Florida cost-
effectiveness of various BMPs will be evaluated.
Austin, Texas has been chosen to demonstrate
various types of porous pavements to evaluate
their effectiveness in the control of both flooding
and pollution from urban stormwater runoff.
Other significant BMP demonstrations projects
have been ongoing throughout the year and have
yielded important results. A study at San Jose,
California has developed sampling procedures to
test street cleaning equipment performance in
real-world conditions. The street cleaning
equipment tests showed that different test area
conditions affected performance more than
differences in equipment type.
The comparison of runoff pollutant
concentrations with recommended water quality
criteria showed that the heavy metals - cadmium,
chromium, lead, mercury, and zinc - as well as
phosphates, BOD, suspended solids, and turbidity
exceeded the recommended criteria. That does not
necessarily mean that a problem exists, but a
problem may arise for these parameters, and they
should be investigated further in receiving waters.
The study showed that aquatic life can be
adversely affected by more pollutants than affect
other beneficial uses.
The concentrations of many pollutants in the
runoff samples were greater than in secondary
treated sanitary sewage effluent. Annual yield
comparisons snowed that the yields for lead,
chromium and suspended solids were greater in
the runoff than in the treated secondary effluent.
Thus, urban runoff may cause some greater
"short- and long-term" receiving water pollution
problems than the treated effluent. The implication
here is that runoff treatment may be a more
effective control measure than improvement in the
partially treated sanitary sewage effluent.
An investigation of periodic sewer flushing
during dry weather for first flush relief is currently
under way at Boston, Massachusetts. A set of
generalized procedures for estimation pollutant
loadings associated with dry weather sewage
solids deposition in combined sewer systems has
been prepared to provide planners, engineers, and
municipal managers with technical information so
that they can make intelligent informed decisions
on potential sewer flushing programs in
combination with other combined sewer
management controls.
Another project currently ongoing at San
Francisco, California, is concerned with the
development of an automatic operational model for
real-tirrfe control of in-line (in-sewer) storage and
routing of storm flows to make maximum use of
existing interceptors and sewer line capacity.
Integrating Flood and Erosion Control Technology
with Pollution Control Technology
Careful consideration must be given to land use
planning since urbanization accelerates
hydrograph and pollutograph peaks and total loads
by creating impervious surfaces for pollutants and
water to run off from. This causes excessive water
pollution, erosion, sedimentation and flooding.
Discreet selection of land management techniques
can reduce drainage and other downstream
control costs associated with these problems.
Established flood and erosion control technology
must be integrated with pollution control
technology so that the retention and drainage
facilities and other nonstructural or low-structural
management techniques required for flood and
erosion control can be simultaneously designed for
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pollution control. Until this is done, the high cost
implications for wet-weather pollution abatement
will continue.
The control of erosion from construction and
developing sites will have a major impact on the
total pollution loads imposed on receiving waters.
Current estimates indicate that approximately
1500 square miles of the United States is
urbanized annually. All of this land is exposed to
accelerated erosion.
Projects at Lake Tahoe, California, and
Columbia, South Carolina, were completed this
year and provide guidelines for cost-effective
methods for controlling erosion and resultant
siltation during urbanization in their respective
geographical areas.
At Lake Tahoe, the soft, sandy soils containing
nutrients and surrounding the lake wash into it
during construction activities, speeding
eutrophication. Figure 22 shows typical conditions
in a hilly area where roads have been cut into the
landscape. Figure 23 shows the area after erosion
control measures were taken as part of the
demonstration project. The willow wattling (i.e.,
the packing of lengths of brush - in this case
willow, but any quick rooting and sprouting species
can be used - into continuous thick cables partially
buried across a slope at regular contour intervals
and supported on the lower side by stakes) and rock
wall provide mechanical stabilization. Grasses
have been planted to provide interim erosion
control and native hardwood plants have been
planted in addition to the willows to provide
permanent cover and stabilization.
Mathematical Models
Models are needed to predict the time varying
rate of runoff and the runoff composition when
there is a storm. The calculation of these
parameters is useful in the planning, design,
operation, and control of wet-weather control
systems. The program has developed a number of
models ranging in complexity from relatively
simple types that require only a calculator to the
sophisticated Storm Water Management Model
(SWMM) which requires a conventional computer.
Work is continuing to improve these models with
incorporation of a variety of subroutines to provide
Figure 22. Lake Tahoe Construction Activity
Before Implementation of Erosion
Control Measures.
Figure 23. Lake Tahoe Construction Area After
Erosion Control Measures were
Taken.
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greater latitude for the users. They are being
utilized widely here and in foreign countries.
Receiving Water Impacts
Data on the environmental impacts of urban
runoff are being gathered as a first step in
developing methodology to quantify pollutant
stress and evaluate the impact in relation to
receiving water standards and desired uses.
Projects at Seattle, Washington, and Milwaukee,
Wisconsin, indicate that one of the most
widespread problems of urban runoff lies with the
settleable particulates as benthic deposits. In the
Milwaukee River, resuspension of sediments has
been shown to cause dissolved oxygen problems,
and the removal of these sediments combined with
conveyance-storage-treatment of combined sewer
overflows was found to be the pollution abatement
alternative which provides the most significant
improvement in water quality as a function of cost.
In the Seattle area, suspended solids from
combined sewer overflows increase the turbidity
in the water column and form sediment deposits
containing increased concentrations of metals,
oils, and greases, and total chlorinated
hydrocarbons. Also, bottom organism and biomass
characteristics in these deposits are different from
bottom areas not influenced by the urban runoff. In
an attempt to track the fate of the suspended
materials discharged to flowing streams, modeling
studies using sediment transport relationships
adapted to urban runoff particulates are underway
at selected sites to determine where the solids are
deposited.
Because of regulated flows, physical
characteristics of the stream, or other unique
features, long term deposition of solids may not be
the cause of the most significant pollution
problems. Immediate impacts such as were
determined .in the Chattahoochee River below
Atlanta, Georgia, where the dissolved oxygen
reached a low of 1.5 mg/l and violated stream
standards as a result of a summer thunderstorm
may be more critical. A nationwide survey of
continuous dissolved oxygen monitors is
underway as part of a study to correlate this type of
dissolved oxygen deficits which occur in receiving
streams below urban areas during wet weather
storm events.
In an effort to catalog existing data, a nationwide
assessment of receiving water impacts from urban
stormwater pollution has been initiated to identify
inpacts and relate the types of potential impacts to
the characteristics of urban areas and their
receiving waters. This assessment will locate
situations in which urban runoff problems are
likely to require control.
Research Reports
Over one dozen research final reports were
published this year on various subjects pertinent to
the program. One of the most important was
entitled URBAN STORMWATER MANAGEMENT
AND TECHNOLOGY - UPDATE AND USER'S
GUIDE, see Figure 24. The report contains
thorough cost and efficiency evaluations of CSO
and urban stormwater control projects completed
since the original 1974 SOTA review.
Figure 24. Research Final Reports - On the Left
is the 1974 SOTA Review and on the
Right is the Most Recent Update
Entitled "Urban Stormwater Man-
agement and Technology-Update
and User's Guide," EPA-600/8-
77-014.
Systems and Economic Analysis Section
This group carries out a wide variety of
mathematical and statistical analyses in support of
other efforts within MERL.
Recently a computerized optimization procedure
called EXEC/OP was developed for use with the
EXECUTIVE program for preliminary design and
cost estimation of wastewater treatment process
systems. EXEC/OP is an efficient computational
procedure for identifying the set of designs which
optimize cost, energy consumption, land
utilization, or some other objective. Up to 40
alternative system designs that are with in a
specified percent of any objective such as cost,
energy, etc. can be identified. A computational
technique known as implicit enumeration is used
in EXEC/OP. The optimization procedure is set up
by specifying a number of stages through which
wastewater and sludge streams flow in a specified
pattern. Each stage contains a number of optional
processes from which only one can be selected to
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form a single system design. All feasible system
designs must produce an effluent discharge
stream equal to or better in quality than the
effluent standards supplied as input to the
program. Design and/or operation decisions for
each process are not continuously variable but
must be discreetly specified and treated as
alternative processes within each stage. Because
of the special requirements of EXEC/OP, several of
the EXECUTIVE subroutines have been revised and
upgraded. These include models for the activated
sludge process, aerobic digestion, heat treatment
of sludge, and truck transport with land disposal of
sludge. Methodology for performing multi-
objective analysis has been developed. The 1977
Amendments to the Clean Water Act permit trade-
offs between cost, energy consumption, and other
criteria. The multi-objective optimization
methodology shows how this requirement can be
rationally approached.
Uptake of heavy metals, such as zinc and
cadmium, from sludge amended soils by various
food crops is an important but poorly understood
phenomenon. Various modeling efforts have been
initiated in an effort to better understand the role of
particular variables in predicting the amount of
plant uptake to be expected. An ionic equilibria
digital computer program was developed to
calculate the concentrations of all ionic species at
equilibrium from mass balance, electroneutrality,
and stability relationships. The Newton-Raphson
method of root finding and Gaussian elimination
were used to solve the system of linearized
equations. A second simpler ionic equilibria
program was developed for the case where pH is
an input variable. A digital computer program for
numerically integrating the equations for flow of
water through one-dimensional non-saturated soil
was developed. The time increment required for
achieving adequate accuracy was about 10-15
seconds which limits the practical use of the
program for studying infiltration over a period of
many years. Finally, a model capable of predicting
heavy metal uptake over long periods of time was
developed but the form of the relationships used
were no better than educated guesses.
To better understand the governing
relationships, experimental measurements of Zn
and Cd uptake by corn from three sources were
statistically analyzed. The analysis showed that
the concentration of both Zn and Cd in the soil was
a linear function of the total amount of metal
applied to the land (Figure 25). The amount found
in the soil was only a fraction of the total amount
applied, suggesting that mobility of the metals is
highly dependent on the soil type. Metal
concentration in the corn leaf was a linear function
of metal concentration in the soil for both Zn and
60
50
40
30
20
10
0
1.2
1.0
0.8
0.6
0.4
0.2
0
Soil Zinc Concentration, mg/kg
50 100150 200250300 350400450500
Soil Cadmium Concentration, mg/kg
2
6 8 10 12 14 16
Figure 25. Relationship Between Soil Metal and
Corn Grain Metal Concentrations
from Experimental Field Experi-
ments on Sludge Amended Land.
Cd although the Cd measurements showed much
greater variability than the Zn measurements. In
one case, yield was found to be a secondary
predictor; the uptake increasing somewhat with
yield. Grain metal concentration was related to soil
metal concentration bya relationshipsimilartothe
Freundlich isotherm where the rate of change of
grain metal with soil metal decreases continuously
as the soil metal concentration increases. For one
location, regressions between grain metal
concentration and total or annual amounts applied
were too weak to statistically support one or the
other predictor as better. Analysis of two additional
sets of metal uptake data showed similar results
except that the Cd uptake by corn grain was
significantly greater in one set than the other two.
The reason for the difference is not known but
might be related to the corn variety or the type of
soil. Current plans are to similarly analyze all
available plant uptake data with the objective of
developing a useful heavy metal uptake and metal
mobility model.
48
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Technical methods for estimating the loss of Separate costs for materials and labor are
toxic volatile organic compounds from the calculated. This program makes it possible to
activated sludge process to the atmosphere were economically evaluate the various route systems
studied and recommendations for an experimental tnat m'9ht be followed in order to check and service
program were made. The principal anV group of plants in a certain area, thereby
recommendation was for measurement of Henry's providing a means for determining the least cost
Law constant at the low concentrations Plan of circuit rider operation. This procedure is
characteristic of wastewater. intended to be part of the framework for a
simulation model that computes the operation and
A computer program called CROM has been maintenance cost for several operational modes of
developed for estimating the annual operation and groups of small treatment plants. The expanded
maintenance costs associated with the circuit rider model will be capable of determining least cost
method of operation for groups of small, operation and maintenance alternatives for groups
independent wastewater treatment plants, of plants located in various regional situations.
REFERENCES
1. Bender, J.H., PARALLEL EVALUATION OF CONSTANT AND DIURNAL FLOW TREATMENT
SYSTEMS, EPA-600/2-78-034, March 1978.
2. Bowker, R.P.G., TREATMENT AND DISPOSAL OF SEPTIC TANK SLUDGES—A STATUS REPORT, in
Small Wastewater Treatment Facilities. USEPA-Tech. Transfer Pub. (Jan. 1978).
3. English, J.N., PRESENT AND FUTURE DIRECTIONS FOR MUNICIPAL WASTEWATER REUSE
RESEARCH, Planning for Water Reuse, Edited by Duane D. Baumann and Daniel M. Dworkin,
Maaroufa Press, Inc., 1978.
4. Field, R.I., et al., URBAN STORMWATER MANAGEMENT WORKSHOP PROCEEDINGS, EPA-600/9-
78-017, 1978.
5. Field, R.I., DISCUSSION: EFFECTS OF STORM FREQUENCYON POLLUTION FROM URBAN RUNOFF,
JWPCF, 50, 5, 974, May 1978.
6. Field, R.I., and Gardner, B., URBAN RUNOFF AND COMBINED SEWER OVERFLOW, JWPCF, 50, 6,
1170, June 1978.
7. Kreissl, J.F., NEW TYPES OF WASTEWATER COLLECTION FOR SMALL COMMUNITIES, in
Wastewater Treatment Systems for Private Homes and Small Communities, 1978.
8. Kreissl, J.F., PRESSURE SEWERS, in Alternatives for Small Wastewater Treatment Systems -II.
USEPA-Tech. Transfer Publication No. EPA-625/4-77-011 (Oct. 1977).
9. Rossman, LA., PLANNING TIME-PHASED REGIONAL TREATMENT SYSTEMS, Journal of the
Environmental Enginering Division, ASCE, 104, EE4, pp. 685-700, August 1978.
10. Rossman, L.A., and Vanecek, FT., A PARTITIONING PROCEDURE FOR WATER QUALITY
MANAGEMENT MODELS, Water Resources Bulletin, 14, 4, pp. 842-855, August 1978.
11. Smith, R. and Eilers, R.G., EFFECT OF STORMWATER ON STREAM DISSOLVED OXYGEN, Journal of
the Environmental Engineering Division, ASCE, 104, EE4, pp. 549-559, August 1978.
12. Smith, R. and Eilers, R.G., STREAM MODELS FOR CALCULATING POLLUTIONAL EFFECTS OF
STORMWATER.RUNOFF, EPA-600/2-78-148, August 1978.
13. Smith, R., TOTAL ENERGY CONSUMPTION FOR MUNICIPAL WASTEWATER TREATMENT, EPA-
600/2-78-149, August 1978.
14. Warner, H.P. and English, J.N., WASTEWATER TREATMENT FOR REUSE AND ITS CONTRIBUTION
TO WATER SUPPLIES, EPA-600/2-78-027, March 1978.
15. WASTEWATER CHARACTERIZATION AND PROCESS RELIABILITY FOR POTABLE WASTEWATER
RECLAMATION, EPA-600/2-77-210, November 1977.
16. ABATEMENT OF DEPOSITION AND SCOUR IN SEWERS, EPA-600/2-77-212, November 1977.
17. ENERGY REQUIREMENTS FOR MUNICIPAL POLLUTION CONTROL FACILITIES, EPA-600/2-77-
214, November 1977.
18. SEWER SYSTEM EVALUATION, REHABILITATION AND NEW CONSTRUCTION - A MANUAL OF
PRACTICE, EPA-600/2-77-017d, December 1977.
19. HANDLING AND DISPOSAL OF SLUDGES FROM COMBINED SEWER OVERFLOW TREATMENT
PHASE II, EPA-600/2-77-053b, December 1977.
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20. HANDLING AND DISPOSAL OF SLUDGES FROM COMBINED SEWER OVERFLOW TREATMENT
PHASE III. EPA-600/2-77-053C, December 1977.
21. TRANSPORT OF SEWAGE SLUDGE, EPA-600/2-77-216, December 1977.
22. URBAN RUNOFF TREATMENT METHODS VOLUME I - NON-STRUCTURAL WETLAND TREATMENT,
EPA-600/2-77-217, December, 1977.
23. CHARACTERIZATION OF REUSABLE MUNICIPAL WASTEWATER EFFLUENTS AND
CONCENTRATION OF ORGANIC CONSTITUENTS, EPA-600/2-78-016, February 1978.
24. EVALUATION OF TRENCHLESS SEWER CONSTRUCTION AT SOUTH BETHANY BEACH,
DELAWARE, EPA-600/2-78-022, March 1978.
25. THE CONSTRUCTION, TECHNICAL EVALUATION, AND FRICTIONAL DETERMINATION OF AN
ALUMINUM STORM SEWER SYSTEM, EPA-600/2-78-025, March 1978.
26. OPTIMIZATION AND TESTING OF HIGHWAY MATERIALS TO MITIGATE ICE ADHESION - INTERIM
REPORT, EPA-600/2-78-035, March 1978.
27. DATA STORAGE AND RETRIEVAL SYSTEM FOR PILOT WASTEWATER TREATMENT RESEARCH,
EPA-600/2-78-036, March 1978.
28. A COMPARISON OF OXIDATION DITCH PLANTS TO COMPETING PROCESSES FOR SECONDARY
AND ADVANCED TREATMENT OF MUNICIPAL WASTES, EPA-600/2-78-051, March 1978.
29. CONVENTIONAL AND ADVANCED SEWER DESIGN CONCEPTS FOR DUAL PURPOSE FLOOD AND
POLLUTION CONTROL, A PRELIMINARY CASE STUDY, ELIZABETH, NJ, EPA-600/2-78-090, May
1978.
30. ENERGY CONSERVATION IN MUNICIPAL WASTEWATER TREATMENT, EPA-430/9-77-011, June
1978.
31. HIGH RATE NUTRIENT REMOVAL FOR COMBINED SEWER OVERFLOWS, EPA-600/2-78-056, June
1978.
32. A STUDY OF FORCED AERATION COMPOSTING OF WASTEWATER SLUDGES, EPA-600/2-78-057,
June 1978.
33. EFFECTS OF THERMAL TREATMENT OF SLUDGE ON MUNICIPAL WASTEWATER TREATMENT
COSTS, EPA-600/2-78-073, June 1978.
34. WATER FACTORY 21: RECLAIMED WATER, VOLATILE ORGANICS, VIRUS, AND TREATMENT
PERFORMANCE, EPA-600/2-78-076, June 1978.
35. THE SWIRL PRIMARY SEPARATOR: DEVELOPMENT AND PILOT DEMONSTRATION, EPA-600/2-
78-122, August 1978.
36. DISSOLVED OXYGEN MEASUREMENT IN INDIANA STREAMS DURING URBAN RUNOFF, EPA-
600/2-78-135, August 1978.
37. PRESSURE AND VACUUM SEWER DEMONSTRATION PROJECT - BEND, OREGON, EPA-600/2-78-
166, September 1978.
38. MANAGEMENT OF SMALL WASTE FLOWS, EPA-600/2-78-173, September 1978.
TREATMENT PROCESS
DEVELOPMENT BRANCH
BIOLOGICAL TREATMENT SECTION
treatment facilities. Major technological advances
The prime objective of this group is to develop in these areas have been reported in USEPA's
processes for achieving requirements for the Environmental Protection Technology Series
National Pollution Discharge Elimination System publications, the professional literature and ERIC
relating to municipal wastewater. Over the past publications.
decade efforts have been devoted to development Currently, efforts are in a transition stage away
of oxygen aeration, lagoon performance, control of from state-of-the-art processes and towards
the nutrients nitrogen and phosphorus, microbial approaches that evidence savings in energy and
degradation, and upgrading of existing municial resources.
50
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Aeration Technology
Clean water oxygen transfer tests conducted by
Los Angeles County on six generically different
submerged air aeration systems suggest
substantial savings in energy may be possible with
recently developed fine bubble devices over the
long-standing coarse bubble options. The second
phase of this project will evaluate several of the
more promising systems under process field
conditions in activated sludge service. The process
studies will determine the extent to which
operation in wastewater (i.e., mixed liquor)
decreases the high oxygen transfer efficiencies
observed with fine bubble equipment in clean
water, and whether the fine porous media of some
of these devices is subject to rapid headless
buildup and unacceptable maintenance
requirements for cleaning. Upon completion of the
project, recommendations will be made to the
Construction Grants Program concerning the
broad application of fine bubble aerators in
municipal treatment.
ABF Process
An evaluation of a full-scale municipal activated
biofilter (ABF) system is underway at Helena,
Montana. ABF employs a unique flow regime
consisting of a redwood media trickling filter tower
followed by a short detention activated sludge unit.
Settled sludge from the activated sludge clarifier is
recycled to the tower, rather than to the head of the
aeration tank in the conventional fashion. This
hybrid configuration reportedly results in excellent
process stability under varying loads and
substantial economies in capital costs contrasted
to either single-stage attached growth systems or
two-stage attached/suspended growth systems
that recirculate settled sludge directly to the
activated sludge stage. This project will for the first
time stress a full-scale municipal ABF installation
to the organic and hydraulic design conditions
recommended by the manufacturer.
Lagoon Solids Control
Two successful demonstrations of algae
removal from lagoon effluents have been
completed. At Veneta, Oregon, a full-scale rock
filter was able to consistently reduce lagoon
system suspended solids levels of 22-105 mg/l
down to 7-14 mg/l. Full-scale intermittent slow
sand filters at Mt. Shasta, California; Moriarty,
New Mexico; and Ailey, Georgia produced effluent
residuals of 8-17 mg/l for BOD and 13-18 mg/l for
suspended solids. This study also revealed that 25-
35% nitrification was occurring across thef liters at
all three sites.
Disinfection of Wastewater Effluent
Emphasis has been on development of
alternative disinfection technology which is
environmentally safe and technologically sound.
Important information was gathered in four major
research areas: (1) chlorination/dechlorination;
(2) ozonation; (3) ultraviolet irradiation; and (4)
support reseach, including indigenous virus
inactivation and non-volatile organics analysis of
disinfection effluents.
Chlorination/Dechlorination
An optimized pilot chlorination system was
evaluated in parallel with several full-scale
treatment facilities. Data indicate that improved
disinfection efficiency is possible in a well-
designed dosing-contact system with a
significantly lower applied dose, and decrease in
acute fish toxicity is directly proportional to the
decrease in the chlorine residual.
A dechlorination study with Los Angeles County
has revealed that dechloration with sulfur dioxide
can be reliable and cost-effective. Reaeration and
pH adjustment are not required in the vast majority
of cases. However, total coliform after-growth
appears to be a pervasive problem, and its solution
is presently obscure.
Ozonation
Substantial progress was made in the in-house
ozone contactor evaluation. Four contactors have
been studied so far: a packed column, jet scrubber,
pressure injector, and a bubble diffuser. The
bubble diffuser shown in Figure 26 is by far the
most efficient contactor both with respect to ozone
utilization and coliform reduction efficiency.
Realistic costs for ozone disinfection, based on
results from the pilot work, have been developed.
The full-scale study of the cost-effectiveness of
disinfection with ozone generated from air has
been completed at the Estes Park, Colorado facility.
A final report will be available soon.
Ultraviolet Light
Excellent progress was made in the full-scale
demonstration project at Northwest Bergen
County Sewer Authority, New Jersey. The
prototype ultraviolet unit has been operating
continuously for 6 months without any major
equipment malfunction or degradation in
disinfection efficiency. The mechanism which
continually wipes the quartz tubes clean has
51
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Figure 26. Pilot Plant Ozone Contactors.
52
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functioned extraordinarily well. Preliminary cost
analyses indicate UV may be competitive with
chlorine as a wastewater disinfectant.
Photoreactivation may be a problem, but more
information needs to be generated. Basic studies
are being conducted at the University of North
Carolina to quantify the effect of applied UV dosage
on microorganism reduction.
Disinfection Support Research
Oak Ridge National Laboratory has been
studying the non-volatile organic fraction of
primary and secondary wastewater effluents
disinfected with chlorine, ozone, and ultraviolet
light. Ultraviolet light, whether used on primary or
secondary effluent, has so far exhibited little effect
on the non-volatile fraction. Ozonation of
secondary effluent apparently destroys some
organic constituents and increases the oxidizable
components. Chlorination of secondary effluent
also destroys some UV-absorbing and oxidizable
constitutents and forms several other
constituents. Similar observations were noted in
primary effluent. One sample of chlorinated
primary effluent exhibited highly mutagenic
properties, whereas none of the treated secondary
effluents were mutagenic.
A study by the Carborundum Company has
indicated that chlorine, ozone, an ultraviolet light
all display to some extent the ability to inactivate
indigenous animal viruses in secondary and
tertiary effluent.
National Symposium on Wastewater
Disinfection
In September, 1978, a symposium on
wastewater disinfection was held in Cincinnati,
Ohio. All the above EPA Grantees and Contractors
presented progress in their specific research
areas. The conference was attended by 250
professionals in the field. Arrangements for
printing of the Proceedings are being made, and
should be available to the public by January or
February, 1979.
PHYSICAL-CHEMICAL TREATMENT SECTION
Toxics Control
It has long been suspected that the tens of
thousands of organic and inorganic compounds
which society now uses in the billions of pounds
per year have left their mark on the environment. In
the opinion of many oncologists, human exposure
to chemicals in the environment may account for
the major cause, up to 85%, of cancers in humans.
These suspicions have been amply confirmed
during the past few years by the exquisite
analytical capabilities of gas chromatography and
mass spectrometry which have identified
hundreds of compounds wherever they have been
sought in the environment. Because so many of
the compounds are toxic or carcinogenic to
humans and aquatic life, the Agency has mounted
a major research effort whose objective can be
broadly described as toxcis control. Emphasis of
the research has focused on a list of 129 organic
and inorganic compounds which have become
known popularly as the priority pollutants. It is
obvious however, that this list will expand to
include other compounds, thus virtually the entire
gamut of synthetic chemical compounds is suspect
until exonerated.
The research activity of the Section is concerned
with toxics in the publicly owned wastewater
treatment plant. The research falls into several
distinct categories, as follows: (1) development of
a data base on the occurrence and concentration of
the priority pollutants entering the Nation's
wastewater treatment plants. Thus, a grant has
been awarded to the University of Washington
which will cooperate with the Georgia Institute of
Technology to survey some 25 municipal plants for
toxic (129 priority pollutants) in the influents, after
primary treatment, and in the effluent discharge
before and after chlorination (if practiced). Sludges
will also be analyzed. Avarietyof plants containing
various compositions of industrial/domestic flows
and treating the wastewaters by a variety of
processes will be surveyed. From this there will
emerge the beginnings of a data base which will
provide information on influent occurrence and
concentration, removals currently being obtained
by a variety of treatment processes and an
evaluation of the toxics in sludges. Certain
compounds tend to accumulate in sludge at
concentrations 10 to 1000 fold higher than the
influent. A corollary, yet extremely important
objective of this study is to develop and verify the
analytical methods that will be used in the survey.
Surrogate tests for toxicity of the effluents, such as
Ames Test and acute fish toxicity will complete the
study.
The data base on the occurrence and distribution
of metals (some 14 are included in the list of
priority pollutants) is being expanded by several
projects now either completed or underway.
Metals discharged to a treatment plant have a
special significance since, in the absence of proper
precautions, they may be cycled from one medium
of the environment to another; since metals cannot
be destroyed, they can only be contained. Thus,
removal from the liquid flow in a plant merely
concentrates the metals in the sludges, in very
much higher concentrations than the influent,
thus placing restraints on the manner by which the
sludges are finally disposed.
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Existing information on metals is being obtained
by a grant with the University of Tennessee which
will locate and evaluate local, state and federal
data on metals that will ultimately permit an
assessment of the sources of the metals
discharged to wastewater treatment plants. A
complementary study is being conducted by
Purdue University which is currently performing a
detailed survey of the City of Kokomo, Indiana.
Data on selected metals and cyanide are being
collected through a comprehensive sampling and
analytical program for stormwater, residential and
industrial flows to the- treatment plant. The
treatment plant itself is also being sampled
intensively. This study will thus provide the date
base for formulating regulations for control of
metals, which are likely to include pretreatment at
industrial sites, improved removals of metals at the
treatment plant and the manner by which the
metals contaminated sludges are finally disposed.
Another objective in the research on toxics is (2)
the treatability/removability of these compounds
by treatment processes. The subject of treatability
is treated separately in this report under the
heading Treatability of Hazardous Compounds.
The treatability of selected toxic compounds is
being examined in-house on a pilot plant*scale.
Five organic compounds are being added to raw
sewage prior to treatment by alum clarification,
dual media filtration and granular activated
carbon. Automatic composite samplers, designed
to avoid loss of volatile organics, collect samples at
appropriate locations in the system and analyzed
by gas chromatographic procedures. Premilinary
data indicate that, from an influent averaging 120-
180 jug/I of each compound, reductions across the
alum-polymer clarification unit range from 11%for
dimethylphthalate to 66% for ethylbenzene. Some
of the volatile substances are undoubtedly lost to
the atmosphere during air-liquid contact. No
further removal occurs during dual-media
filtration.
A five-minute (empty bed) contact time carbon
adsorber operating on dual-media filter effluent
maintained the concentration of the five organics
to less than detectable levels for only 1-2 weeks.
The order of breakthrough to 25% of influent
concentration of the compounds assayed was,
first, carbon tetrachloride, then, trichloroethylene,
dimethylphthalate, nitrobenzene and
ethylbenzene. Only carbon tetrachloride and
trichloreothylene had begun to break through the
carbon at a contact time of 15 minutes after five
weeks on stream. Complete loading data from the
column operation, together with laboratory
equilibrium tests will help to clarify the role of
activated carbon in the removal of toxic organics
from municipal wastewaters.
A third and final overall objective of toxics
control is (3) evaluation of treatment processes for
removal of toxics and development of proess
improvements for removal. A start in this direction
is a research grant with the University of Michigan
which will investigate the addition of powdered
activated carbon to the aeration process in
activated sludge plants. In anticipation that
process economics may be affected by the cost of
powdered carbon, a study with Stanford Univeristy
was undertaken to seek a cheaper but equivalent
powdered carbon to current commercial products.
A variety of waste carbonaceous sources, other
than coal or wood, is being treated by processes
including pyrolysis and activation to produce a
powdered activated carbon. The two major
reactions will be optimized and the resulting
carbons matched by performance against
commercial products.
ULTIMATE DISPOSAL SECTION
Municipal wastewater sludges contain insoluble
and adsorbed impurities resulting from
wastewater treatment. Wastewater sludges also
contain human wastes, pathogenic organisms and
higher life forms, and industrial wastes ranging
from highly toxic substances to innocuous
materials such as food wastes.
The primary responsibility of the Ultimate
Disposal program is to find environmentally
acceptable and cost-effective approaches for
treating and disposing of municipal wastewater
sludges. Therefore, the objectives are to improve,
adapt, and develop the processing, treatment, and
conversion technology for the conditions expected
to prevail in the near future and during the next
decade.
The sludge research program is divided into the
following subdivisions:
1. sludge processing and treatment
2. sludge conversion
3. Beneficial utilization and disposal
Sludge processing and treatment includes all of
the steps from the first appearance of sludge until
it enters the disposal step. Anaerobic digestion is
an example. Sludge conversion is any process that
changes the nature of the sludge so that it is no
longer perceived as sludge. Composting is an
example. Beneficial utilization includes any
constructive use of sludge. Landspreading of
sludge on soil for beneficial use of its fertilizer and
organic content is an example of constructive use.
Sludge Processing and Treatment
The heavy metals content of sludges,
particularly that of cadmium, tends to inhibit
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exploitation of land disposal as an attractive
method of final disposal of sludge solid. The
technical and economic feasibility of removing
heavy metals from sludge using a hot acid process
has recently been studied under a contract with
Walden Research. The process involves
acidification of the sludge (pH 2-3) and heating to
temperatures below boiling (about 95°C). Test
results show that the process can solubilize the
cadmium and the other heavy metals in varying
percentages. In addition, the process improves the
dewaterability of the sludge and destroys all
pathogens. A preliminary economic analysis of the
process indicates that it is cost-competitive with
alternative stabilization and conditioning
processes. A demonstration of the heavy metals
removal processes at pilot scale is planned.
The use of solar energy in wastewater treatment
operations continues to receive attention. The
desk-top project completed by Environmental
Systems, Inc., showed that solar heating of
anaerobic digesters was economically and
technically feasible through the United States.
This concept will be utilized at full scale at Wilton,
Maine. The Wilton plant will be the first to
demonstrate innovative energy savings concepts
that will make use of an integrated energy system
of solar energy, digester methane gas, and process
heat recovery. A contract jointly supported by EPA
and the Department of Energy will document all
aspects of the Wilton solar energy experience.
The progress of wastewater treatment
technology has been rapid in recent years. The
result has been the generation of new types of
sludges and the development of new processes to
handle both new and conventional sludges. The
design engineer is often virtually without
information when he must design new facilities. A
substantial portion of our effort has gone into
filling this information gap.
An example of a study inaugurated to provide
vitally needed design information is the survey of
the impact of phosphorus removal sludges on
wastewater treatment plant operation. Removal of
phosphorus from wastewater normally entails
precipitation of phosphates by the addition of a
chemical, generally either lime or a salt of iron or
aluminum. A consequence of phosphorus
removal, therefore, is the production of sludge
which is laden with chemical precipitates. Sludge
mass is increased and its properties are changed,
usually for the worse. The survey of 174 plants
removing phosphorus by chemical addition,
produced very useful information. The dominant
chemical used is iron, ejther as a ferric salt or a
waste pickle liquor from metal treatment. Lime is
least used. Iron salts produce the least impact on
sludge processing. Generally sludge processing
facilities such as anaerobic digesters and vacuum
filters become overloaded. An unexpected
complaint wasthe increase in energy requirement.
More sludge produced, often of lower solids
content, means that more fuel must be used to
raise it to digestion temperatures or to incinerate it.
The increase in costs and overloading of
equipment, particularly dewatering equipment,
has produced a definite movement towards land
application of liquid sludge.
A similar study has been made of the use of heat
treatment for conditioning sludge. Controversy has
arisen as to whether the negative impacts (odor
production, high BOD return stream, high capital
cost) are counterbalanced by the positive impacts
(easy filtration, high solids cake, no need for
conditioning chemicals). An objective assessment
of the process at working heat treatment plants
was carried out and results were made available to
designers and municipalities. Emphasized wasthe
need for pilot plant operation before design, grit
removal, odor control, and a high level of
mechanical skill in the workforce. Documentation
showed the significant increase in cost with
decreasing plant size; for example, costs are an
exorbitant $260/dry ton of sludge solids for a 1
mgd (3785 mVd) plant. The information made
available should help prevent overenthusiastic use
of the heat treatment process where it really is not
needed, and should prevent the design errors
(such as inadequate odor control) that have created
a negative attitude toward the process.
The need for producing a stabilized sludge that is
essentially free of pathogens is another
controversial subject. In some cases, such a result
is clearly desirable. Thermophilic (ca. 50°C)
digestion processes have this effect but have been
either unstable or too costly to consider. MERL is
supporting development of two stable thermophilic
digestion processes that may be close enough in
cost to conventional digestion procedures that the
economic disincentive to choose a process that
produces a pathogen-free sludge will disappear.
Cornell University has tested an aerobic digestion
process that reaches 50°C without addition of
external heat. The City of Hagerstown is going to
demonstrate Union Carbide's aerobic-anaerobic
digestion process that disinfects the sludge with
one day of aerobic digestion (achieves 55°C by
using oxygen) and follows it with eight days
anaerobic digestion that produces methane.
Sludge Conversion
The U.S. Department of Agriculture's Static-Pile
Forced-Aeration Composting Process, developed
with MERL and other EPA support, has continued
55
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to provide solutions to sludge disposal problems in
many areas of the country. Camden's full-scale
plant is in operation, and both New York and New
Jersey are planning to make extensive use of this
process as they phase out ocean dumping of
sludge. EPA reports, for example, A Study of
Forced Aeration Composting of Wastewater
Sludges, (EPA 600/2-78-057, June 1978) have
received wide circulation.
In some locations, unconfined composting has
met with objections. Studies are underway to
evaluate within-vessel composting processes.
European technology is being evaluated and the
cost evaluation of a compost plant that fits
conveniently on a river barge is planned.
Thermal conversion processes which offer less
pollution potential than incineration have been
developed with MERL assistance. Plans are being
developed to evaluate starved-air combustion
processes that produce a fuel gas and recover
energy when these gasses are combusted. EPA's
Construction Grants program is providing the
capital funds for construction, while MERL will
provide funds for an evaluation period. MERL has
an evaluation now underway of Duluth's co-
incineration plant, where refuse-derived fuel will
provide the fuel for combusting sewage sludge.
Beneficial Utilization and Disposal
The options for selection of systems for
treatment, handling, and disposal of sewage
sludge are numerous, but the choices of ultimate
receptors for the sludge are few. Land is the only
acceptable receiver. Sludge may be utilized in or
near the surface soil to enhance soil productivity or
it may be sequestered beneath the surface soil.
The former offers the opportunity to consume
some of the useful constituents of sludge while
disposing of it economically in an energy-use
efficiency manner. Sequestering sludge in
landfills, basins, or trenches offers the possibility
of economical disposal where sludge quality or site
conditions make landspreading unfeasible. More
information is needed for development of
technology for utilizing or disposing of sludge
under the multitude of sludge-soil-climate-land
use conditions that may be encountered in
planning and construction of public wastewater
treatment facilities.
Plant nutrients and organic matter can be
beneficial to soil and make it more productive. Both
inorganic and organic components of sludge can,
however, be harmful to the environment or
hazardous to public health if they are added to soil
in excessive amounts. The amount of each
component that is acceptable is dependent upon
site characteristics and management and
regulations.
A sizeable portion of MERL's research effort has
been devoted to determining the fate and effects of
the nutrients and trace elements in sludge-treated
soils. Copper, nickel, and zinc have been identified
as metals that are more likely to accumulate to
phytotoxic levels in sludge-treated soils. Cadmium
is the element of most concern because of its
potential adverse effects on human health. It is
assimilated by growing plants and is accumulated
in the liver and kidneys of the consumer. Lead is of
concern if sludge-contaminated forages are
ingested, by animals. Nitrates can leach into
ground water, and both nitrates and phosphates
can be transported by surface runoff into streams
and reservoirs. Progress has been made in
identifying acceptable sludge application rates and
appropriate site management techniques for
application of specific sludges on specific soil-
climate-crop combinations. A grant to Chicago is
supporting a study of the accumulative effects of
annual sludge applications over a long period of
time. After 10 years, cadmium concentration in
grain does not appear to be increasing. No
phytotoxicity from metals has been encountered.
Corn yields from sludge-treated soils are
equivalent to, or superior to, conventionally
fertilized plots. With MERL support, the Science
and Education Administration of the U.S.
Department of Agriculture at St. Paul, Minnesota,
is developing site management technology to
enable the beneficial use of sludge as a soil
amendment. Diversion terraces, contour
cultivation, and appropriate cropping systems are
being used to minimize runoff and leaching of
soluble and suspended sludge constituents.
Animal feeding of sludge-produced corn silage is
being used to determine the effect of the cadmium-
enriched feed on animal health, carcass
composition, and milk composition.
Toxic organic substances that mayfindtheir way
into sludge are of increasing interest. The principal
known organic constituents of sludge are PCBs
and pesticides, but concentrations of persistent
pesticides in sludge are usually lower than in soils
to which they were Applied, so sludge application
should be of concern only if sludges with unusually
high pesticide concentrations are used. PCBs are
adsorbed on soils and have low solubility, plant
uptake is negligible, but surface contamination of
crops could be significant.
The transmission of pathogenic organisms
through sludge use on soil is of concern. At the
University of Illinois, under a MERL grant, the
effect on the parasite population in worm-free pigs
foraging on sludge-treated soils is being studied.
Direct feeding of sludge, and feeding of crops from
sludge-amended soils at Denver have not
-------
produced disease in cattle. An epidemiological The technology for improving disturbed or
study of humans and domestic animals is part of a impoverished lands with sludge will be improved
large-scale utilization demonstration in Ohio being by data being generated in ongoing studies
supported by a grant to the Ohio Farm Bureau supported by grants to MSD-Chicago and the
Development Corporation. This project also Pennsylvania Department of Environmental
demonstrates institutional arrangements and
informational activities to involve the public in Resources to study the use of sewage sludge in
planning and implementation of sludge disposal reclaiming stripmine spoils.
projects. Selected toxic organic substances that may be in
Studies to be initiated in FY 1979 include sludge will be studied in greenhouse and field plots
identification of non-food chain crops that can be to determine their fate and effects when they are
produced on sludge-amended soils, and applied to agricultural soils as a constituent of
demonstration of sludge use to produce non-food sludge. Crop uptake and leaching rates will be
chain crops. Production of food chain crops on measured.
sludgetreated soils may not be feasible under all
circumstances because of regulations, Astudy of landfilling of sewage sludge alone and
contaminated sludge, or environmental with municipal refuse will be initiated to identify
constraints. In these cases, the production of non- safe practices and provide management guidance
food chain crops such as trees for energy or fiber, information. The fate of toxic and pathogenic
or ornamentals may offer an economical and components of sludge under various landfilling
resource-conserving option. practices will be determined.
REFERENCES
1. Barth, E.F., and Ryan, B.W.,NUTRIENT CONTROL BY PLANT MODIFICATION AT EL LAGO, TEXAS,
JWPCF, 50, 1768, 1978.
2. Barth, E.F., Tabak, H.H., and Mashni, C.I., BIODEGRADATION STUDIES OF CARBOXYMETHYL
TARTRONATE, Municipal Environmental Research Laboratory, Cincinnati, Ohio45268. EPA600/2-
78-115, July 1978.
3. Brenner, R.C., A SUMMARY OF EPA EFFORTS IN EVALUATING OXYGEN-ACTIVATED SLUDGE, in
The Use of High Purity Oxygen in the Activated Sludge Process, J.R. McWhirter, Ed., CRC Press, Inc.,
West Palm Beach, Florida, 1978.
4. Bunch, R.L., INTRODUCTION AND OBJECTIVES OF SYMPOSIUM, Proceedings of Symposium on
Performance and Upgrading Wastewater Stabilization Ponds, Utah State University, Logan, Utah,
August 23-25, 1978.
5. Bunch, R.L, THE MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY, Annual Meeting,
Water Resources Committee of the Manufacturing Chemists Association, Cincinnati, Ohio,
September 21, 1978.
6. Bunch, R.L, WASTEWATER AND SLUDGE RESEARCH PROGRAM, Proceedings of Sixth US /Japan
Conference on Sewage Treatment Technology, Cincinnati, Ohio, October 30-31, 1978.
7. Bunch, R.L., MEASURING THE DEGREE OF SLUDGE STABILITY, Proceedings of Sixth US/Japan
Conference on Sewage Treatment Technology, Cincinnati, Ohio, October 30-31, 1978.
8. Bunch, R.L, THE FUTURE COURSE OF WASTEWATER AND SLUDGE DISINFECTION, Proceedings
of 2nd Assises Internationales de I'Environnement, Paris, France, December 5-6, 1978.
9. Bunch, R.L., PILOT PLANT DEVELOPMENT OF OZONE DISINFECTION, Proceedings of 2nd Assises
Internationales de I'Environnement, Paris, France, December 5-6, 1978.
10. Dobbs, R.A., Middendorf, R.J., and Cohen, J.M., CARBON ADSORPTION ISOTHERMS FOR TOXIC
ORGANICS, Municipal Environmental Research Laboratory, Cincinnati, Ohio 45268, May 1978.
11. Eralp, A.E., DISCUSSION ON CONSERVATIVE APPROACH TO ENERGY RESOURCES
DEVELOPMENT, Engineering Issues, 103, 4, 306, 1977.
12. Eralp, A.E., and Tomson, B., pH AVERAGING, JWPCF, 50, 389, 1978.
13. Eralp, A.E., Nancollas, G.H., and Gill, J.S., CALCIUM SULFATE SCALE FORMATION: A KINETIC
APPROACH, Society of Petroleum Engineers Journal. 18, 133, 1978.
14. Farrell, J.B., MISTAKEN TERMINOLOGY, JWPCF, 49, 1752, 1977.
15. Farrell, J.B., and Wall, H.O., OVERVIEW OF SOME NEW THERMAL CONVERSION TECHNIQUES
FOR SLUDGE DISPOSAL, Proceedings 5th National Conference on Acceptable Sludge Disposal
Techniques, January 31-February 2, 1978.
57
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16. Fochtman, E.G., and Dobbs, R.A., ADSORPTION OF CARCINOGENIC COMPOUNDS BY ACTIVATED
CARBON, Proceedings of ACS Annual Meeting, Miami Beach, Florida, September 10-15, 1978.
17. Hannah, S.A., Jelus, M., and Cohen, J.M., REMOVAL OF UNCOMMON TRACE METALS BY
PHYSICAL AND CHEMICAL TREATMENT PROCESSES, JWPCF, 49, 2297, 1977.
18. Johnson, B.A., Wight, J.L., Middlebrooks, E.J., Reynolds, J.H., and Venosa, A.D , MATHEMATICAL
MODEL FOR THE DISINFECTION OF WASTE STABILIZATION LAGOON EFFLUENT JWPCF 50
2002, 1978.
19. Lewis, R.F., HISTORICAL REVIEW OF OXIDATION PONDS AS THEY IMPACT SECONDARY
TREATMENT AND WATER QUALITY, Proceedings of Symposium on Performance and Upgrading
Wastewater Stabilization Ponds, Utah State University, Logan, Utah, August 23-25, 1978.
20. Lewis, R.F., Editor, and Palmer, C.M., ALGAE AND WATER POLLUTION, Municipal Environmental
Research Laboratory, Cincinnati, Ohio 45268. EPA-600/9-77-036.
21. Lucas, J.B., Pahren, H.R., Ryan, J.A., and Dotson, G.K., POTENTIAL HEALTH RISKS ASSOCIATED
WITH LAND DISPOSAL OF MUNICIPAL SLUDGES, presented at Conference on Land Application of
Liquid Wastes, Colorado State University, Fort Collins, Colorado (To be published).
22. Meckes, M.C., and Venosa, A.D., COMPARISON OF MPN AND MF TECHNIQUES OF ENUMERATING
COLIFORM BACTERIA IN OZONATED WASTEWATER EFFLUENT, National Symposium on
Wastewater Disinfection, September 18-20, 1978, Cincinnati, Ohio.
23. Moses, C.T., Young, K.W., Stern, G., and Farrell, J.B., CO-DISPOSAL OF SLUDGE AND REFUSE IN A
PUROX CONVERTER, presented at the American Chemical Society Meeting, March 1978, Anaheim,
California.
24. Nash, N.P., Krasnoff, J., Pressman, W.B., and Brenner, R.C., OXYGEN AERATION AT NEWTOWN
CREEK, JWPCF, 49, 388,1977.
25. Opatken, E.J., ECONOMIC EVALUATION OF OZONE CONTACTORS, National Symposium on
Wastewater Disinfection, September 18-20, 1978, Cincinnati, Ohio.
26. Pahren, H.R., Lucas, J.B., Ryan, J.A., and Dotson, G.K., THE IMPACT OF METALS PRESENT IN
MUNICIPAL SLUDGES UPON THE HUMAN FOOD CHAIN - A RISK ASSESSMENT, JWPCF (To be
published).
27. Rya«i, J.A., CADMIUM: UTILIZATION AND ENVIRONMENTAL IMPLICATION, Proceedings 1st
Annual Conference of Applied Research and Practice on Municipal and Industrial Waste, Madison,
Wisconsin, September 1978.
28. Stenquist, R.J., Parker, D.S., Loftin, W.E., and Brenner, R.C., LONG-TERM PERFORMANCE OF A
COUPLED TRICKLING FILTER-ACTIVATED SLUDGE PLANT, JWPCF. 49, 2265, 1977.
29. Stern, G., and Farrell, J.B., SLUDGE DISINFECTION TECHNIQUES, Proceedings of 1977 National
Conference on Composting of Municipal Residues and Sludges, August 23-25, 1977.
30. Tabak, H., and Barth, E., BIODEGRADATION OF BENZIDINE IN AEROBIC SUSPENDED GROWTH
REACTORS, JWPCF, 50, 552, 1978.
31. Tabak, H., MICROBIAL DEGRADATION OF POLLUTANTS IN MARINE ENVIRONMENTS, ATe.cr\ical
Summary of Workshop held April 9, 1978, Pensacola, Florida.
32. Venosa, A.D., Meckes, M.C., and Opatken, E.J., COMPARATIVE EFFICIENCIES OF OZONE
UTILIZATION AND MICROORGANISM REDUCTION IN DIFFERENT OZONE CONTACTORS, National
Symposium on Wastewater Disinfection, Sept. 18-20, 1978, Cincinnati, Ohio.
33. Villiers, R.V., and Farrell, J.B., A LOOK AT NEWER METHODS FOR DEWATERING SLUDGES, Civil
Engineering. ASCE, 47, 12,66,1977.
34. Westrick, J.J., REMOVAL OF VOLATILE HALOGENATED ORGANIC COMPOUNDS BY ACTIVATED
CARBON, US/USSFt Joint Symposium, Cincinnati, Ohio, March 20-21, 1978.
35. Westrick, J.J., Cummins, M.D., and Cohen, J.M., BREAKPOINT CHLORINATION/ACTIVATED
CARBON TREATMENT: EFFECT ON VOLATILE HALOGENATED ORGANICS, Municipal
Environmental Research Laboratory, Cincinnati, Ohio 45268.
36. APPRAISAL OF POWDERED ACTIVATED CARBON PROCESSES FOR MUNICIPAL WASTEWATER
TREATMENT, A.J. Shuckrow, Battelle-Northwest, Richland, Washington 99352 and G.L. Gulp, El
Dorado Hills, California 95630. EPA-600/2-77-156, September 1977.
37 DISINFECTION EFFICIENCY AND RESIDUAL TOXICITY OF SEVERAL WASTEWATER
DISINFECTANTS - VOLUME II - WYOMING, MICHIGAN, R.W. Ward and G.M. DeGraeve, Grand Valley
State Colleges, Allendale, Michigan 49401 and R.D. Giffin, City of Wyoming, Michigan 49509. EPA-
600/2-77-203, November 1977.
58
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38. HIGH ENERGY ELECTRON RADIATION OF WASTEWATER LIQUID RESIDUALS, A Report to the U.S.
National Science Foundation by the Massachusetts Institute of Technology, December 21, 1977,
under NSF Grant ENV 74 1 3016 (partially funded by USEPA under IAG with NSF). NTIS.
39. TRANSPORT OF SEWAGE SLUDGE, W.F. Ettlich, Culp/Wesner/Culp, Clean Water Consultants, El
Dorado Hills, California 95630. EPA-600/2-77-216, December 1977.
40. RECENT DEVELOPMENTS IN THE SANDIA LABORATORIES' SEWAGE SLUDGE IRRADIATION, H.D.
Sivinski, et al., SAND 77-1411. NTIS.
41. SEWAGE SLUDGE ENTRENCHMENT FOR USE BY SMALL COMMUNITIES, J.M. Walker, et al..
Agricultural Research Service, Beltsville, Maryland 20705. EPA-600/2-78-018, February 1978.
42. PERFORMANCE EVALUATION OF THE AERATED LAGOON SYSTEM AT WINDBER,
PENNSYLVANIA, C.M. Earnest, E.A. Vizzini, D.L. Brown, and J. L. Harris, University of Pittsburgh at
Johnstown, Johnstown, Pennsylvania 159-4. EPA-600/2-78-023, March 1978.
43. FULL-SCALE DEMONSTRATION OF NITROGEN REMOVAL BY BREAKPOINT CHLORINATION, R.W.
Stone, Sacramento, California 95827. EPA-600/2-78-029, March 1978.
44. SOLUBLE ORGANIC NITROGEN CHARACTERISTICS AND REMOVAL, S.J. Tandtke, G.F. Parkin, J.V.
Keller, J.O. Leckie, and P.L. McCarty, Stanford University, Stanford, California 94305. EPA-600/2-
78-030, March 1978.
46. BENEFICIAL DISPOSAL OF WATER PURIFICATION PLANT SLUDGES IN WASTEWATER
TREATMENT, J.O. Nelson, North Marin Sanitary District, C.A. Joseph, Novato Sanitary District, and
R.L. Gulp, Clean Water Consultants. EPA-600/2-78-089, May 1978.
47. SEPARATION OF ALGAL CELLS FROM WASTEWATER LAGOON EFFLUENTS, VOL. I:
INTERMITTENT SAND FILTRATION TO UPGRADE WASTE STABILIZATION LAGOON EFFLUENT, S.E.
Harris, D.S. Filip, J.H. Reynolds, and E.J. Middlebrooks, Utah State University, Logan, Utah 84322.
EPA-600/2-78-033, June 1978.
48. A STUDY OF FORCED AERATION COMPOSTING OF WASTEWATER SLUDGE, W. F. Efflich and A. E.
Lewis, Culp/Wesner/Culp, Clean Water Consultants, El Dorado Hills, California 95630. EPA-600/2-
78-057, June 1978.
49. NITRIFICATION OF SECONDARY MUNICIPAL WASTE EFFLUENTS BY ROTATING BIO-DISCS, J. A.
Borchardt, S. J . Kang, T. H. Chung, The University of Michigan, Ann Arbor, Michigan 48109. EPA-
600/2-78-061, June 1978.
50. STUDY OF ACTIVATED SLUDGE SEPARATION BY DYNAMIC STRAINING, J. Dumanowski and A.
Strom, FMC Corporation, Itasca, Illinois 60143. EPA-600/2-78-070, June 1978.
51. EFFECTS OF THERMAL TREATMENT OF SLUDGE ON MUNICIPAL WASTEWATER TREATMENT
COSTS, L. J. Ewing, et al., Culp/Wesner/Culp, Clean Water Consultants, El Dorado Hills, California
95630. EPA-600/2-78-073, June 1978.
52. SEPARATION OF ALGAL CELLS FROM WASTEWATER LAGOON EFFLUENTS, VOL. Ill: SOIL
MANTLE TREATMENT OF WASTEWATER STABILIZATION POND EFFLUENT - SPRINKLER
IRRIGATION, B. T. Hicken, et al., Utah State University, Logan, Utah 84322. EPA-600/2-78-097, July
1978.
53. AUTOTROPHIC DENITRIFICATION USING SULFUR ELECTRON DONORS, A. W. Lawrence, et al.,
Cornell University, Ithaca, New York 14853. EPA-600/2-78-113, July 1978.
54. USE OF SOLAR ENERGY TO HEAT ANAEROBIC DIGESTERS, J. W. Malcolm and D. F. Cassel,
Environmental Systems, Inc., Annapolis, Maryland, 21401. EPA-600/2-78-114, July 1978.
55. THE COUPLED TRICKLING FILTER-ACTIVATED SLUDGE PROCESS: DESIGN AND PERFORMANCE,
R. J. Stenquist and D. S. Parker, Brown and Caldwell, Walnut Creek, California 94596 and W. E.
Loftin, City of Livermore, Livermore, California 94550. EPA-600/2-78-11 6, July 1978.
56. MATERIALS FOR OXYGENATED WASTEWATER TREATMENT PLANT CONSTRUCTION, H. K. Uyeda,
et al.. Bureau of Reclamation, Denver, Colorado 80225. EPA-600/2-78-136, July 1978.
57. RECLAMATION OF A LANDFILL WITH DIGESTED SEWAGE SLUDGE, R. R. Rimkus, et al.,
Metropolitan Sanitary District of Greater Chicago, Chicago, Illinois 60611. EPA-600/2-78-120,
August 1978.
58. SLUDGE DEWATERING AND DRYING IN SAND BEDS, D. D. Adrian, University of Massachusetts,
Amherst, Massachusetts 01003. EPA-600/2-78-141, August 1978.
59. FULL-SCALE DEMONSTRATION OF LIME STABILIZATION, R. F. Noland, et al., Burgess and Niple,
Ltd., Columbus, Ohio 43220. EPA-600/2-78-171, September 1978.
59
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DRINKING WATER RESEARCH DIVISION
The Drinking Water Research Division (DWRD) of MERL has the responsibility of determining the
occurrence of contaminants and of conducting research and development to establish the water
treatment and control technology in accordance with the provisions of the Safe Drinking Water Act of
1974 (Public Law 93-523). The Division maintains liaison with the Office of Drinking Water in the Office of
Water and Waste Management to insure that research requirements of the Act can be met in a timely
fashion.
The Drinking Water Research Division provides as focal point for the coordination of all water supply
research activities located in various geographical locations and organizational units: Municipal
Environmental Research Laboratory, Cincinnati, Ohio; Health Effects Research Laboratory, Cincinnati,
Ohio; Environmental Monitoring and Support Laboratory, Cincinnati, Ohio; the Environmental Research
Laboratory, Athens, Georgia; and the Environmental Research Laboratory, Ada, Oklahoma. The director of
DWRD also serves as the coordinator of these functions and arranges for technical assistance to the Office
of Drinking Water as well as to the states, to water utilities, and to the general public.
The research is performed in two branches of the Division, the Physical and Chemical Contaminants
Removal Branch and the Microbiological Treatment Branch. Descriptions of their activities over the 14
months covered by this report follow. Major issues that have spotlighted the research effort during that
time include the investigation of treatment practices to minimize the presence of organics in treated
water, the examination of treatment technology and associated costs to reduce contaminant levels to
those specified in the National Interim Primary Drinking Water Regulations (NIPDWR), the use of
disinfectants other than chlorine and the determination of whether harmful by-products are formed, the
removal of asbestos fibers from drinking water, the removal of Giardia lamblia from public water supplies
not using filtration, the development of rapid methods for the detection of bacteria, the relationship of
turbidity to disinfection efficiency, the role of viruses in disinfection, and the evaluation of point-of-use
treatment devices.
PHYSICAL AND CHEMICAL
CONTAMINANTS
REMOVAL BRANCH
The objectives of the in-house and extramural section will be a list of articles published during
research conducted by the Physical and Chemical that time.
Contaminants Removal Branch are to develop
economic drinking water treatment unit processes ...__^ ...,^ ^^.„.„..,..„ .,,.„
to allow a water utility of any size to meet the '"ORGANIC CONTAMINANTS
Drinking Water Regulations, either those presently Jar test and pilot plant studies (Figure 27) were
effective or those contemplated in the future, and completed on the removal of the trace metals listed
to devise techniques to allow the distribution of in the National Interim Primary Drinking Water
water to the consumer without deterioration in Regulations (NIPDWR) by conventional
quality. To accomplish this, the Branch is divided coagulation and lime softening, and research
into five research areas: Inorganic Contaminants, begun on the removal of specific problem
Particulate Contaminants, Organic Contaminants, contaminants selenium, arsenic, fluoride, and
Economic Analysis, and Distribution System nitrate by other treatment techniques. Except for
Quality. Discussion to follow will be divided into arsenic, these four contaminants are not
these five categories and will summarize the effectively removed from water by conventional
research accomplishments from October 1977 coagulation and lime softening. Moreover, all four
through December 1978. At the end of each substances occur in ground water and thus are
61
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Figure 27. Mixing Tanks for Portable Pilot Plant for Conventional Treatment.
anticipated to present the greatest number of
problems to small communities using well water.
Activated alumina, which has been effectively
used to remove fluoride from water, was shown to
remove both selenium IV and VI from water under
certain conditions. The reverse osmosis process
was also found to be very effective for selenium
removal (90-95 %). Reverse osmosis can achieve
very high fluoride and arsenic V removals (90-95
%) and moderate nitrate removal (75-85%) and
arsenic III (60-70%). Although reverse osmosis is
expensive and not commonly used for drinking
water treatment, the technique has certain
advantages; it is useful for treating water high in
total dissolved solids and having multiple
contaminants that cannot be removed by
conventional treatment methods.
Field projects to complement inhouse research
were funded to investigate the removal of all the
inorganic contaminants listed in the NIPDWR from
ground water by reverse osmosis; selenium from
ground water by activated alumina; and nitrate
from ground water by ion exchange and reverse
osmosis. All of these projects will provide practical
information for the design and operation of
treatment systems both small and large to remove
these specific contaminants. Economic data will
also be developed.
Detailed information on completed jar test and
pilot plant studies (Figure 28) for trace metal
removal is being published in a series of articles in
the Journal of the American Water Works
Association.
REFERENCES
1. Sorg, T.J., TREATMENT TECHNIQUES FOR THE REMOVAL OF INORGANIC CONTAMINANTS FROM
WATER, Manual of Treatment Techniques for Meeting Interim Primary Drinking Water Regulations,
U.S. Environmental Protection Agency, EPA-600/8-77-005, May 1977, Revised April 1978.
2. Lodsdon, G.S., TREATMENT TECHNIQUES FOR THE REMOVAL OF RADIOACTIVE CONTAMINANTS
FROM WATER, Manual of Treatment Techniques For Meeting Interim Primary Drinking Water
62
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Figure 28. Settling Tank for 2 gpm Coagulation-Sedimentation Pilot Plant.
Regulations, U.S. Environmental Protection Agency, EPA-600/8-77-005, May 1977, Revised April
1978.
3. Sorg, T.J., TREATMENT TECHNOLOGY TO MEET THE INTERIM PRIMARY DRINKING WATER
REGULATIONS FOR INORGANICS (PART 1, NITRATE AND FLUORIDE), JAWWA. 70, 2, 105-112
(Feb. 1978).
4. Sorg, TJ. and Logsdon, G.S., TREATMENT TECHNOLOGY TO MEET THE INTERIM PRIMARY
DRINKING WATER REGULATIONS FOR INORGANICS: PART 2 (ARSENIC AND SELENIUM), JA WWA,
70, 7, 379-393 (July 1978).
5. Clifford, D.A. and Weber, W J., NITRATE REMOVAL FROM WATER BY ION EXCHANGE, EXECUTIVE
SUMMARY, Environmental Technology Series, EPA 600/8-77-015, Municipal Environmental
Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio, Nov. 1977.
PARTICULATE CONTAMINANTS
Particulate removal studies continued for two
types of contaminants - asbestos fibers and
Giardia cysts.
The Drinking Water Research Division has
studied granular media filtration for removal of
amphibole and chrysotile asbestos fibers at
Duluth, Minnesota, Seattle, Washington, and
Philadelphia, Pennsylvania. At Duluth, the 30 mgd
plant shows amphibole removal consistently
exceeding 99%, with filtered water turbidities of
0.04to0.05 nephelometric turbidity units(ntu) and
amphibole fiber counts of 0.01 to 0.1 * 106
fibers/liter (f/l). As a result of one especially
severe storm, the amphibole fiber count rose to
1200 x 1Q6 f/l. The filtration plant, then operating
with sedimentation, reduced the amphibole
concentration to 0.048 * 106 f/l, while turbidity
was being reduced from 14 ntu to 0.05 ntu.
Minnesota State Health Department Data show
amphibole fiber removals of nearly 99% at new
plants in Two Harbors and Silver Bay. Duluth can
use conventional filtration with settling or direct
filtration (settling omitted). Plants at Two Harbors
and Silver Bay are direct filtration plants (Figure
29).
63
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Figure 29. Filtration Gallery at a Major Water Utility.
Three large conventional plants in Philadelphia
consistently reduced asbestos concentrations
from 106to 107f/l to 0.1 * 106 f/I or less during a
five month study period in 1977-1978. Production
of a filter effluent turbidity of 0.1 ntu is one of the
quality goals at Philadelphia.
The 20 gpm granular media filtration pilot plant
treating clear Cascade Mountain water at Seattle
effectively removed asbestos fibers when effluent
turbidity was below 0.10 ntu. The direct filtration
process repeatedly produced water with chrysotile
asbestos counts of 0.2 * 10s f/l or less, with
numerous samples below limits of detection. Raw
water chrysotile content ranged from 1 to 20 * 106
f/l. When filtered water turbidity rose above 0.1
ntu, asbestos fiber count in the filtered water rose
dramatically. This study suggests that turbidity
may be used as an indicator of effective filter
performance for asbestos fiber removal.
Because outbreaks of waterborne giardiasis
have been documented only in recent years,
information on the removal of Giardia cysts at
water filtration plants is limited to filtration failures
associated with outbreaks.
Filtration for removal of Entomoeba histolytica
cysts was studied in the 1930's and 1940's.
Granular media filtration was effective for E.
histolytica cyst removal if the water was properly
preconditioned first. Minimum preconditioning
required was effective coagulation. Sedimentation
also aided in cyst removal. Recent laboratory work
with Giardia muris cysts (a mouse parasite) has
shown that coagulation and sedimentation can
reduce cyst concentrations up to 99%. One
analysis showed the zeta potential (related to
electrophoretic mobility) of G. muris was negative,
a result similar to those for clays and bacteria.
Army research in World War II showed that
diatomaceous earth filtration was effective for
removal of E. histolytica cysts, and two filtration
tests with G. lamblia cysts indicated thatdiatomite
filtration also removes this type of cyst.
Both previous work and present work with 9 /urn
radioactive microspheres used as cyst models
show that good plant operating procedures are
necessary if diatomaceous earth filtration plants
are to be an effective barriertothe passage of cysts
into drinking water. The filters should be precoated
with 0.2 pounds of diatomite per square foot of
filter surface, and body feed must be added to
maintain the integrity of the filter cake. Filtered
water, not raw water, should be used to prepare
the precoat slurry.
64
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Figure 30. Overview of Portable Pilot Plant for Conventional Treatment.
University of Washington through a research
grant.
Studies of Giardia cyst removal will continue at
the DWRD pilot plant (Figure 30) and at the
REFERENCES
1. Logsdon, G.S., TREATMENT FOR REMOVAL OF TURBIDITY, Manual of Treatment Techniques for
Meeting Interim Primary Drinking Water Regulations, U.S. Environmental Protection Agency, EPA-
600/8-77-005, May 1977, Revised April 1978.
2. Logsdon, G.S., DIRECT FILTRATION - PAST, PRESENT, FUTURE, Civil Engineering -ASCE, 48, 7, 68-
73, July 1978.
ORGANIC CONTAMINANTS
Aeration and adsorption with both granular
activated carbon and synthetic resin are treatment
processes being evaluated for use where ground
waters are contaminated by organic contaminants,
e.g. industrial cleaning solvents. Usmg pilot scale
columns, in-house researchers have conducted
studies at three New England Water Utilities.
Sufficient preliminary treatment data was
gathered to warrant an expanded extramural
project at Glen Cove, New York (Long Island).
Two documents were prepared in conjunction
with the proposed regulation on trace organics in
drinking water. One, Interim Treatment Guide for
Controlling Organic Contaminants in Drinking
Water Using Granular Activated Carbon, provides
background technical information on the efficacy
of several water treatment processes for organic
removal (reduction), and the other document,
Operational Aspects of Granular Activated Carbon
Adsorption Treatment, addresses specific
questions often asked on this topic.
Analytical efforts are complete on three
contractual assignments dealing with the control
of trihalomethanes (Figure 31). Two of these
projects were pilot scale adsorption studies(one in
Lawrence, Massachusetts and the other is in
Kansas City, Missouri) and the third examined the
effects of altering the practice of breakpoint
65
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Figure 31. Analytical Equipment for Measure-
ment of Trihalomethanes.
chlorination at a lime softening water treatment
plant (Huron, South Dakota). The final reports are
being prepared.
A major extramural research project report on
the current international technology of ozonation
and chlorine dioxide usage in drinking water
treatment was published. In this report, special
attention was given to collection of on-site data for
engineering design of treatment systems and to a
comprehensive treatise on the organic oxidation
products resulting from chlorine dioxide and ozone
application. Information is also presented on the
use of ozone in combination with granular
activated carbon.
Research continued on the combination of ozone
and granular activated carbon (GAG) as a means of
extending carbon bed life. In house, a pilot-scale
project is investigating four parallel systems —
oxygen only, high (5.0 mg/L) ozone dose, low (0.5
mg/L) ozone dose and a control. Extramurally,
three research projects at Miami, Florida,
Philadelphia, Pennsylvania and Shreveport,
Louisiana will investigate, at pilot-scale, the
combination of ozone and GAC in a variety of raw
waters.
Research has continued in the study of organic
byproducts of disinfection other than the
trihalomethanes. Several aliphatic substituted
benzenes which were not normally characterized
as increasing on chlorination have been found at
higher levels in a chlorinated drinking water than
its surface water source. A refined carbon
adsorbable organic halogen as chloride (CAOX)
procedure was used to examine organic
byproducts from humic acid solution treated with
chlorine and chlorine dioxide. Chlorine
substitution from chlorine treatment is
approximately ten times that accounted for by
trihalomethane formation. Although it appears to
be less than that with chlorine, chlorine
substitution is also observed with chlorine dioxide
applications at low doses. The halogenated
compounds formed from both disinfectants remain
as high molecular weight species not amenable to
gas chromatographic analysis. The CAOX
procedure has been an extremely useful tool in this
area of research.
Methodology has been developed to employ
glass capillary gas chromatography with flame
ionization detection to examine the organic
profiles of extracts from water samples. This
methodology is currently being used to evaluate
granular activated carbon (GAC) effectiveness for
removal of organics from both pilot plant and full
scale treatment plant operations.
Research has begun to investigate the removal
of specific organic compounds using GAC (Figure
32). Isotherm and kinetics data is also being
generated to be used for evaluation of GAC
adsorption computer models. Initial selection of
the compounds to be studied was based on toxicity
and occurrence data.
The basic objective of our field investigations
efforts is to evaluate and develop water treatment
technology that minimizes the presence of
potentially harmful organics in drinking water. The
research projects involve technology directed at
minimizing the concentrations of organic
substances associated with the disinfection of
drinking water, such as trihalomethanes and
precursors, and specific organic substances that
occur in the source waters and are not
substantially removed by commonly used water
treatment methods. The projects also include
evaluation of the costs required for a given
technology, whenever the scale of the project is
large enough.
Current investigations include studies of
adsorbents, alternative disinfectants and
modification of the points of application of
disinfection to minimize organic contamination.
Also onsite carbon regeneration technology is
under investigation.
Granular activated carbon (GAC) studies
involving both full-scale contactors and pilot
columns are progressing at a site along the lower
Mississippi. Two, six-month phases of full-scale
operation of gravity GAC beds using lower
Mississippi river water have been completed. One
bed was operated as a post-filter adsorber while
the other one was operated as a sand replacement
system. Preliminary results were reported in 1978
at the AWWA in Atlantic City, New Jersey and at
the ACS in Miami, Florida. A recently started third
phase incorporates pilot column studies in parallel
operation with the full-scale beds.
At a site on the Ohio River, a six-month phase of
operating three 5 mgd sand replacement GAC beds
and a parallel pilot column utilizing Ohio River
66
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Figure 32. GAC Used to Investigate Removal of Specific Organic Compounds.
source water has been completed. A recently
instituted second phase of pilot column
investigation involves using two types of carbon
operated as post filter adsorbers along with
columns operated as sand replacement systems
with virgin and once reactivated carbon.
A lower Ohio River study is using the full-scale
plant as a control and a pilot plant at this location is
being used for comparison of the effects of chlorine
and chlorine dioxide disinfection both with and
without GAC. Various modes of operation will be
evaluated in short term tests and a mode selected
for long-term evaluation.
A project designed to conduct full-scale
treatment modifications at 7 utilities and to
monitor the raw and finished purgeable organic
compound levels at 11 utilities has been
completed. The project compared the performance
of virgin granular activated carbon (GAC) vs. aged
carbons, an evaluation of GAC performance of
three virgin carbons, several studies to assess the
value of moving the chlorine application point, a
study to evaluate ammoniation, and a study to
compare the use of chlorine dioxide to chlorine as a
disinfectant. Data from the 11 utilities was
collected monthly from July 1977 through June
1978 and represents the first time such a data
bank exists for the Ohio River Valley.
In 1979, full-scale operation of two on-site
carbon reactivation systems is scheduled to begin.
Both of these regenerators will befluidized bed and
will reactivate carbon that has been used for
surface water treatment (one utilizing Ohio River
water and the other a Northeast lake).
A study of the synthetic adsorbents XE-340 and
IRA 904 as well as granular activated carbon has
been completed in Southern Florida. The source
water was a ground water containing high TOC
and trihalomethane precursor concentrations and
specific organics. A final report will be published in
1979. The results of the completed study have
been used to initiate a new project using an ozone-
GAC system.
REFERENCES
1. Dressman, R.C. and McFarren, E.F., DETERMINATION OF VINYL CHLORIDE MIGRATION FROM
POLYVINYL CHLORIDE PIPE INTO WATER, JAWWA, 70, 29-30, January 1978.
67
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2. Dressman, R.C., Fair, J., and McFarren, E.F., A DETERMINATIVE METHOD FOR THE ANALYSIS OF
AQUEOUS-SAMPLE EXTRACTS FOR BIS (2-CHLORO) ETHERS AND DICHLOROBENZENES,
Environmental Science and Technology, 11,719, July 1 977.
3. Sylvia, A.E. and O'Brien, J.E., LIFE EXPECTANCY OF GRANULAR ACTIVATED CARBON, (U.S. EPA
Contractors), Journal New England Water Works Association, December 1977.
4. Sylvia, A.E., Miller, J.K., and Baxter, W.S., PRELIMINARY INVESTIGATIONS INTO THE PRESENCE OF
HALOFORMS IN MASSACHUSETTS DRINKING WATER SUPPLIES, (U.S. EPA Contractors) Journal
New England Water Works Association, March 1 978.
5. Stevens, A.A., Seeger, D.R., Slocum, C.J., PRODUCTS OF CHLORINE DIOXIDE TREATMENT OF
ORGANIC MATERIALS IN WATER, In Proceedings of International Ozone Institute Workshop,
Ozone/Chlorine Dioxide Oxidation Products of Organic Materials, November 17-19, 1976,
Cincinnati, Ohio. R.G. Rice, J.A. Cotruvo, eds., International Ozone Institute, Cleveland, Ohio, pp.
383-399(1978).
6. Pfaender, F.K., Stevens, A.A., Haas, J.R., Moore, L. and Jones, R.B., EVALUATION OF THE DIRECT
AQUEOUS INJECTION METHOD FOR ANALYSIS OF CHLOROFORM IN DRINKING WATER,'
Environmental Science and Technology, 12, 438, April 1978.
7. Weber, W.J. Jr., Pirbazari, M., Herbert, M. and Thompson, R., EFFECTIVENESS OF ACTIVATED
CARBON FOR REMOVAL OF VOLATILE HALOGENATED HYDROCARBONS FROM DRINKING
WATER, (EPA Grantees, Univ. of Mich., Ann Arbor), In: Viruses and Trace Contaminants in Water and
Waste Water, Ann Arbor Science Publishers, Ann Arbor, Michigan, 1977.
8. Weber, W.J. Jr., Pirbazari, M., and Melson, G.L, BIOLOGICAL GROWTH ON ACTIVATED CARBON:
AN INVESTIGATION BY SCANNING ELECTRON MICROSCOPY, (EPA Grantees, University of
Michigan, Ann Arbor), Environmental Science and Technology, 12, 817.
9. Baum, B. and Morris, J.C., PRECURSORS AND MECHANISMS OF HALOFORM FORMATION IN
CHLORINATION OF WATER SUPPLIES, (EPA Grantees, Harvard University, Boston), In: Proceedings
of 2nd Conference on Water Chlorination, Environmental Impact and Health Effects, Gatlinburg,
Tennessee, October 31 - November 4, 1977, pp. 29-48 (1978).
10. Dressman, R.C., Fair, J., and McFarren, E.F., THE EVALUATION OF 15% ETHYL ETHER/HEXANE AS
THE EXTRACTING SOLVENT FOR BIS(2-CHLORO-> ETHERS IN WATER, Journal of Environmental
Science Health, A13(2), 139-147(1978).
11. Dressman, R.C., McFarren, E.F., and Symons, J.M., AN EVALUATION OF THE DETERMINATION OF
TOTAL ORGANIC CHLORINE (TOCI) IN WATER BY ADSORPTION ONTO GROUND GRANULAR
ACTIVATED CARBON, PYROHYDROLYSIS, AND CHLORIDE ION MEASUREMENT, In: Proceedings
AWWA Water Quality Technology Conference, Kansas City, Missouri, December 5-6, 1977,
American Water Works Association, Denver, Colorado, Paper 3A-5, (1978).
12. Dressman, R.C., McFarren, E.F., and Symons, J.M., PROCEDURES FOR APPLICATION OFTHE CAOX
AS Cl- METHOD TO DISINFECTED WATER, Addendum to: AN EVALUATION OF THE
DETERMINATION OF TOTAL ORGANIC CHLORINE (TOCI) IN WATER BY ADSORPTION ONTO
GROUND GRANULAR ACTIVATED CARBON, PYROHYDROLYSIS, AND CHLORIDE ION
MEASUREMENT, In: Proceedings AWWA Water Quality Technology Conference, Kansas City,
Missouri, December 5-6, 1977, American Water Works Association, Denver, Colorado, Paper 3A-5,
(1978). '
13. Stevens, A.A. and Symons, J.M., MEASUREMENT OF TRIHALOMETHANE AND PRECURSOR
CONCENTRATION CHANGES OCCURRING DURING WATER TREATMENT AND DISTRIBUTION,
JAWWA, 69, 10, pp. 546-554, October 1977.
14. Symons, J.M., Carswell, J.K., Clark, R.M., Dorsey, P., Geldreich, E.E., Heffernan, W.P., Hoff, J.C.,
Love, O.T. Jr., McCabe, LJ. and Stevens, A.A., OZONE, CHLORINE DIOXIDE, AND CHLORAMINES AS
ALTERNATIVES TO CHLORINE FOR DISINFECTION OF DRINKING WATER STATE-OF-THE-ART, In:
Proceedings of Second Conference on Water Chlorination. Environmental Impact and Health Effects,
Gatlinburg, Tennessee, October 31 - November 4, 1977, pp. 555-560 (1978).
15. Symons, J.M., INTERIM TREATMENT GUIDE FOR CONTROLLING ORGANIC CONTAMINANTS IN
DRINKING WATER USING GRANULAR ACTIVATED CARBON, U.S. Environmental Protection
Agency, Cincinnati, Ohio, (Unpublished).
16. Symons, J.M., Love, O.T. Jr., and Carswell, K., OZONE/CHLORINE DIOXIDE OXIDATION PRODUCTS
OF ORGANIC MATERIALS, In: Proceedings of International Ozone Institute Workshop,
OZONE/CHLORINE DIOXIDE OXIDATION PRODUCTS OF ORGANIC MATERIALS, November 17-19,
1976, Cincinnati, Ohio, R.G. Rice, J.A. Cotruvo, eds., (1978), pp. 443-955.
68
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17. Christman, R.F., Johnson, J.D., Haas, J.R., Pfanender, F.K., Liao, W.T., Norwood, D.L., and Alexander,
H.J., NATURAL AND MODEL AQUATIC HUMICS: REACTIONS WITH CHLORINE, In: Water
Chlorination, Environmental Impact and Health Effects, Vol. 2, Ann Arbor Science Publishers, Ann
Arbor, Michigan, 1978.
18. DeMarco, J. and Wood, P., DESIGN DATA FOR ORGANICS REMOVAL BY CARBON BEDS, In.
Proceedings of National Conference on Environmental Engineering - Research, Development and
Design, Kansas City, Missouri; Environmental Engineering Speciality Conference, pp. 149-156, July
11, 1978.
19. Snoeyink, V.L, McCreary, J.J., and Murin, C.J., ACTIVATED CARBON ADSORPTION OF TRACE
ORGANIC COMPOUNDS, University of Illinois, Grant No. R-803473, EPA-600/2-77-223,
Environmental Protection Technology Series, December 1977.
20. Miller, G.W., Rice, R.G., Robson, C.M., Scullin, R.L, Kuhn, W. and Wolf, H., AN ASSESSMENT OF
OZONE AND CHLORINE DIOXIDE TECHNOLOGIES FOR TREATMENT OF MUNICIPAL WATER
SUPPLIES, Environmental Protection Technology Series, EPA-600/2-78-147, Municipal
Environmental Research Laboratory, Drinking Water Research Division, Cincinnati, Ohio, August
1978.
ECONOMIC ANALYSIS
One of the major problems facing EPA in
implementing the Safe Drinking Water Act is that
of small systems compliance. Small systems
(10,000 people or less) may have difficulties in
meeting the Act's requirements. Economies of
scale insure that unit costs for water provided by
small utilities are higher than in larger utilities. If
these small water systems have to invest in
additional expensive treatment processes, the cost
burden may be more than many small
communities can afford to pay.
In order to provide realistic information
concerning these anticipated cost burdens, afield
study of 10 small water systems in each of EPA
Regions III, V, VI, VIII, IX, and X has been
conducted. Costs were broken down according to
acquisition, treatment, water delivery, and support
services. Raw and finished water samples were
taken at each utility and water quality problems
identified. Where necessary, treatment technology
designed to solve these problems was
hypothesized, associated costs were calculated,
and added to the existing baseline data. From this
exercise, it was possible to realistically assess the
costs of compliance which may be experienced by
some small water systems. On the average for
utilities studied, costs increased by 10% but for
some individual systems costs increased by two or
three times.
In parallel to the above-mentioned study, a field
study of the cost effectiveness of package water
treatment plants was completed. Package water
treatment plants are prefabricated units
constructed on site. This initial construction cost
may be half that of conventional treatment.
The study revealed that properly operated
package plants can treat water to meet the drinking
water standards at reasonable cost.
A standardized cost accounting system that
could be used by all utilities has been completed
and operated for one year in a small utility. Work is
currently under way to develop a financial
reporting system that will utilize data from the cost
accounting system to generate standardized fiscal
reports.
Recently, an interim report from an extramural
effort designed to determine the cost of various
unit processes, singly and in combination, has
been published. This report contains costs of
conventional unit processes, and for such special
unit processes as granular activated carbon.
REFERENCES
1. Clark, R.M., THE SAFE DRINKING WATER ACT: ITS IMPLICATION FOR PLANNING, In: Municipal
Water Systems: A Challenge for Urban Resource Management. D. Holtz and S. Sebastian, eds.,
Indiana University Press, February 1978.
2. Helms, B.P. and Clark, R.M., FINANCING MUNICIPAL WATER SUPPLY, Journal of the American
Water Works Association, 70, 5, May 1978, pp. 240-245.
3. Clark, R.M., Gillean, J.I. and English, J.N., COST STUDIES FOR RENOVATED WASTEWATER, Journal
of the Water Pollution Control Federation, 50, April 1978, pp. 688-697.
4. Gillean, J.I., Adams, W.K., and Clark, R.M., THE COST OF WATER SUPPLY AND WATER UTILITY
MANAGEMENT, VOL. I, Socioeconomic Environmental Studies Series, EPA-600/5-77-015a,
69
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Municipal Environmental Research Laboratory, U.S. Environmental Protection Agency, Cincinnati,
Ohio, November 1977.
5. Goddard, H.C., Stevie, R.G., and Trygg, G.D., PLANNING WATER SUPPLY. COST-RATE
DIFFERENTIALS AND PLUMBING PERMITS, Socioeconomic Environmental Studies Series, EPA
600/5-78-008, Municipal Environmental Research Laboratory, U.S. Environmental Protection
Agency, Cincinnati, Ohio, May 1978.
DISTRIBUTION SYSTEM WATER QUALITY
In the area of metal pipe corrosion, several
projects are underway. A portable device for
measuring the concentration of lead, zinc and
cadium by anodic stripping voltametry has been
developed under an interagency agreement and is
now being field tested in the Seattle distribution
system. This device should allow water utilities to
easily assess the dissolution of the toxic metals
lead and cadmium in their distribution systems.
In a grant with the University of Florida a number
of systems in Florida are being evaluated in an
effort to determine if a Modified Langelier Index or
some other relationship might be more useful in
predicting corrosion in metal pipes with the kind of
water encountered in Florida. If these studies are
successful the results should also aid utilities in
other parts of the country as presently available
corrosion indicators generally appear inadequate.
In-house studies on the corrosion of lead pipe
are continuing and the influence of various
corrosion control techniques such as the use of
zinc orthophosphate and sodium bicarbonate
addition with pH adjustment are being evaluated.
An interesting side development of these studies
has been the finding that it may be possible to
analyze the films developed on the pipe in these
studies or found on the pipe in natural systems by
the use of Raman spectroscopy. The analysis of
these films should enable us to more readily
predict the effectiveness of attempts to control
corrosion in any system.
In the area of organic contaminants, the possible
migration of polynuclear aromatic hydrocarbons
(PAHs) from asphalt or coal-tar lined pipes into the
distributed water is being evaluated. Static tests
have been conducted in the laboratory and a
number of field installations utilizing asphalt
(petroleum base) lined cast iron pipe have been
studied. In the static tests, water is allowed to
remain in contact with a short section of lined pipe
for several days before being analyzed for PAHs. In
the field studies, grab samples are collected at the
end of an asphalt lined pipe. Thus far, in both
cases, relatively low levels of PAHs have leached
into the water. In the case of coal-tar lined pipes,
however, total PAH concentrations as high as 4 ;ug
per liter were found. Thus, further studies of both
types are being conducted on coal-tar lined pipe to
determine how long after installation these
compounds continue to leach from the pipe and in
what amounts.
Another study concerned with organic
contamination has been an evaluation of the total
organic chlorine determination developed in
Germany by Kuhn, Fuchs and Sontheimer. In this
determination, organohalides are adsorbed onto
granulated activated carbon, the carbon
undergoes pyrohydrolysis, and the resulting
chloride is determined by microcoulometric
titration. The method has been modified,
simplified, and adapted also to the determination
of disinfected water. The results of these latter
studies have shown that much of the purgeable
material remains unaccounted for when the
original non-disinfected water methodology is
used. A first production model of an instrumentfor
measuring total carbon adsorbable halides is now
being evaluated in-house.
With respect to particulate contamination, a
grant with the City of Greenwood, South Carolina
to treat its water with zinc orthophosphate in order
to control corrosion of the asbestos cement (A/C)
pipe in its system is nearing completion and
preliminary data indicate that the treatment is
helpful. An in-house study utilizing sections of
A/C pipe inserted in a circulating system with
water treated with zinc orthophosphate and
adjusted to pH 8.3 also indicates that this
treatment prevents softening of the pipe and loss
of calcium from the pipe, whereas water untreated
or treated with zinc orthophosphate but at pH 7.0
produced softening of the pipe and a significant
increase in the calcium content of the water.
REFERENCES
1. McFarren, E.F., Buelow, R.W., Thurnau, R.E., Gardels, M., Sorrell, R.K., Snyder, P. and Dressman,
R.D., WATER QUALITY DETERIORATION IN THE DISTRIBUTION SYSTEM, In: Proceedings A WWA
Water Quality Conference, Kansas City, Missouri, Dec. 5-6, 1977,The American Water Works
Association, Denver, Colorado, Paper 2A-1 (1978).
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Sorrell, R.K., Dressman, R.C. and McFarren, E.F., HIGH PRESSURE LIQUID CHROMATOGRAPHY
FOR THE MEASUREMENT OF POLYNUCLEAR AROMATIC HYDROCARBONS IN WATER, In:
Proceedings AWWA Water Quality Technology Conference, Kansas City, Missouri, Dec. 5-6, 1977,
The American Water Works Association, Denver, Colorado, Paper 3A-3 (1978).
Dressman, R.C., McFarren, E.F., and Symons, J.M., AN EVALUATION OF THE DETERMINATION OF
TOTAL ORGANIC CHLORINE (TOCI) IN WATER BY ADSORPTION ONTO GROUND GRANULAR
ACTIVATED CARBON, PYROHYDROLYSIS, AND CHLORIDE ION MEASUREMENT, In: Proceedings
AWWA Water Quality Technology Conference, KansasCity, Missouri, Dec. 5-6,1977,The American
Water Works Association, Denver, Colorado, Paper 3A-5, (1978).
MICROBIOLOGICAL
TREATMENT BRANCH
The research strategy for the Microbiological
Treatment Branch is addressing several issues in
response to the proposed regulations for the
control of organic chemical contaminants. These
research areas include 1)the use of modified water
treatment techniques including activated carbon
and changing the point of disinfection, 2) the use of
alternate disinfectants to chlorine such as chlorine
dioxide, ozone, and chloramines, 3) application of
the standard plate count as a means of evaluating
changes in the sanitary quality of water, and 4)
how all of these factors might be integrated to
effect the overall quality of water. Research needs
of EPA Water Supply Regional programs have also
been identified and those areas of highest concern
have been integrated into ongoing program
directions or scheduled for early starts over the
next two years.
The technical approach in the research strategy
includes both intramural and extramural research
in the laboratory, using pilot plant operations and
field sites for full scale evaluations. This year's
report summarizes research accomplishments in
the area of distribution system quality,
disinfection, point-of-use treatment attachments,
and rapid methods development, during the period
October 1977 to September 1978.
DISINFECTION
Research on the microbiological aspects of
drinking water disinfection continues to have a
high priority in the Microbiological Treatment
Branch. The consideration of alternatives to
chlorine for drinking water disinfection and the
need for information on the relationship of
turbidity to disinfection efficiency continue to be
the major factors influencing the disinfection
research program. Several extramural projects in
this area funded in the last two years have been
completed or are nearing completion.
The results of a study on the resistance of
several enteroviruses to different chlorine species
indicate that changes in pH within the range
encountered in water treatment have important
effects on the resistance of viruses to inactivation
by chlorine. These effects are quite apart from the
effects of pH on the disinfectant chemical species
present. In addition, previous results indicating a
pronounced effect on the disinfectant efficiency of
chlorine by inorganic salts such as potassium
chloride were confirmed. The results of this study
show the difficulty in assessing the relative
disinfection efficiency of chlorine species and
other disinfectants and also some of the problems
associated with attempts to choose a single virus
to serve as a valid disinfection indicator under all
circumstances.
Research on the effects of virus aggregation on
disinfection resistance of enteroviruses and on the
factors which influence virus aggregation and
dispersion in water is in the final year of a three
year project. Some of the more important results
include: 1) the tendency of viruses to aggregate or
disperse seems to be an individual characteristic of
various enteroviruses but some common
characteristics are evident. Aggregation does not
appear to be related to viral isoelectric point. All
viruses studied tend to aggregate at low pH (3 to 6)
and to disperse at high pH (8 to 11]f. Low
concentrations of metalic ions tend to enhance
aggregation while higher concentrations enhance
dispersion. Divalent and trivalent cations are more
effective than monovalent cations and anions
appear to have little influence. 2) While
aggregation can cause deviation from first order
inactivation kinetics, dispersed viruses do not
always show first order inactivation kinetics. The
reason for the deviation is unknown but does not
appeartobegenetically related. 3)The relationship
between disinfectant concentrations and
disinfectant rate is not linear. Although rates
increase as disinfectant concentration increases,
chlorine and bromine are more efficient at lower
concentrations. Analysis of the initial phases of the
inactivation patterns produced by HOCI and OCI-
suggest that the two disinfectants may inactivate
viruses by different mechanisms.
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As a result of the increasing frequency of
waterborne outbreaks of giardiasis in recentyears,
a research program on the protozoan etiologic
agent Giardia lamblia and on treatment technology
needed to prevent such outbreaks was initiated in
1976. As a part of this effort, a symposium on
Waterborne Transmission of Giardiasis, jointly
sponsored by MERL and the Health Effects was
held September 18-20, 1978 in Cincinnati. The
purpose of the symposium was to assess the state
of our knowledge of the organism, the disease, its
epidemiology, detection methodology and
treatment technology, and to determine the
direction of future research in this area.
In attendance were approximately 200 people
representing in approximately equal numbers
governmental research and regulatory agencies,
water utilities, and academic institutions. In
addition to papers by MERL and HERL personnel
and grantees, the program included presentations
by National Institutes of Health, Communicable
Disease Control, and U.S. State Department,
Office of Medical Services personnel.
One of the highlights of the symposium was a
report by a MERL grantee describing successful
development of a culture method for determining
Giardia cyst viability. This important breakthrough
has made disinfection studies on this organism
feasible and also is important with regard to
detection methodology development. Disinfection
research on the cysts of this microorganism is now
in progress.
The results of three separate research projects
relating to the effects of microbial association with
particulate matter on the disinfection efficiency of
chlorine, chlorine dioxide, and ozone were
presented at the annual American Water Works
Association meeting in Atlantic City in June 1978.
The results of each of these studies bear out initial
findings indicating that the degree of protection
conferred depends to a great extent on the type of
particulates associated with the microorganisms
rather than the amount of particulate matter
present as measured by turbidity. Final reports on
these projects will be available in FY-79.
The Microbiological Treatment Branch staff
participated in the preparation of a Report to
Congress entitled, Human Viruses in the Aquatic
Environment: A Status Report with Emphasis on
the EPA Research Program. Preparation of this
report was mandated by the Safe Drinking Water
Act. It will serve as a guide to Congress and the
Agency in determining the future course of virus
research related to drinking water.
REFERENCES
1. Floyd, R. and Sharp, D. G., EFFECTS OF LOW pH AND IONIC VALENCE ON AGGREGATION OF POLIO
AND REOVIRUSES, \n: Abstracts ofthe Annual Meeting ofthe American Society for Microbiology, p.
255, No. P 4, 1977, 77th Annual Meeting, New Orleans, Louisiana, May 8-13, 1977.
2. Young, D. C., Floyd, R., and Sharp, D. G., DIFFERENCES IN AGGREGATING CONDITIONS AND
DISINFECTION RATES FOR TWO ENTEROVIRUSES, In: Abstracts of the Annual Meeting of the
American Society for Microbiology, p. 255, No. P 5, 1977, 77th Annual Meeting, New Orleans,
Louisiana, May 8-13, 1977.
3. Scarpino, P. V., Cronier, S., Zink, M. L, Brigano, F. A. O., and Hoff, J. C., EFFECT OF PARTICULATES
ON DISINFECTION OF ENTEROVIRUSES AND COLIFORM BACTERIA IN WATER BY CHLORINE
DIOXIDE, Proceedings of the American Water Works Association's Water Quality Technology
Conference, December 1977, Kansas City, Missouri.
4. Cronier, S., Scarpino, P. V., and Zink, M. L, CHLORINE DIOXIDE DISINFECTION OF VIRUSES AND
BACTERIA IN WATER, (U.S. EPA Grantee), Water Chlorination: Environmental Impact and Health
Effects, Vol. 2, R. L. Jolly, H. Gorchev, and D. H. Hamilton, Jr. (Eds.) pp. 651 -658, Ann Arbor Science
Publishers Inc., Ann Arbor, Michigan (1978).
5. Floyd, R. and Sharp, D. G., VIRAL AGGREGATION: QUANTITATION AND KINETICS OF THE
AGGREGATION OF POLIOVIRUS AND REOVIRUS, (U.S. EPA Grantee) Applied & Environmental
Microbiology, 35, 6, 1079-1083, June 1978.
6. Floyd, R., and Sharp, D. G., VIRAL AGGREGATION: EFFECTS OF SALTS ON THE AGGREGATION OF
POLIOVIRUS AND REOVIRUS AT LOW pH, (U.S. EPA Grantee) Applied & Environmental
Microbiology, 35, 6, 1084-1094, June 1978.
7. Hoff, J.C. and Geldreich, E.E., ALTERNATIVE DISINFECTANTS FOR DRINKING WATER: OZONE,
CHLORINE DIOXIDE, CHLORAMINES, Proceedings of the 20th Annual Public Water Supply
Engineer's Conference, April 3-5, 1978, Champaign, Illinois, pp. 41-52.
8. Hoff, J.C. and Geldreich, E.E., EFFECTS OF TURBIDITY AND OTHER FACTORS ON THE
INACTIVATION OF VIRUSES BY CHLORINE, Proceedings: 1978 Annual AWWA Conference and
Exposition, Atlantic City, New Jersey, June 25-30, 1978 (In Press).
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9. Sproul, O.V., Emerson, M.A. Howser, D.M., Boyce, D.S., Walsh, D.S., and Buck, C.E., EFFECTS OF
PARTICULATE MATTER ON VIRUS INACTIVATION BY OZONE, Proceedings: 1978 Annual AWWA
Conference and Exposition, Atlantic City, New Jersey, June 25-30, 1978 (In Press).
10. Scarpino, P.V., ViRICIDAL EFFECTIVENSSS OF DISINFECTION PROCESSES - CHLORINE DIOXIDE,
Proceedings: 1978 Annual AWWA Conference and Exposition, Atlantic City, New Jersey, June 25-
30, 1978 (In Press).
DISTRIBUTION SYSTEM STUDIES
After treatment, potable waters are subject to
continuing deterioration of microbiological quality.
The extent of this microbial degradation is
dependent on source water quality, type of
treatment, residual disinfectant, distribution/
storage system design, climate and other physical
and chemical factors. To assess the impact of these
factors on finished water quality, the
Microbiological Treatment Branch has several
extramural projects and in-house tasks related to
field and laboratory studies of microbiologically
mediated deterioration in distribution systems.
Ongoing field studies are evaluating the effects
of turbidity levels greater than one unit on bacterial
survival and regrowth in distribution systems in
areas of the Northeast (Salem-Beverly,
Massachusetts and Nasson College, Maine),
MidAtlantic (University of Delaware and Johns-
Hopkins University), Midwest (University of
Missouri) and West Coast (University of California).
In addition to the turbidity aspect of these studies,
they each include related areas of study peculiar to
the given system. Salem-Beverly, for instance, has
been studying chlorine resistant, encapsulated
bacteria imbedded in sediment deposits in their
distribution system as well as identifying the other
bacterial groups present and relating population
changes to treatment modifications. A grant with
ORSANCO (Ohio River Valley Water Sanitation
Commission) is also studying effects of treatment
modifications on the bacterial quality of water
supplies. Johns-Hopkins University has been
studying the problems related to cross-conections
and is now beginning a study of pathogen survival
in a turbid, finished water system. A related in-
house task is evaluating the effect of handling and
storage on bacteriological changes in potable
water samples prior to analysis. Information being
developed in this project has a direct bearing on all
the distribution studies as well as an impact on
utility compliance with the Drinking Water
Standards, since some sample storage is
inevitable in any distribution system sampling
program.
Previous results have demonstrated that the
type of turbidity is as important as the amount, with
regard to disinfection and bacterial survival.
Studies at Oregon State University, University of
California and NassonCollege(Maine)will attempt
to identify the physical and chemical parameters
contributing to the various types ot turbidity, and
how these factors relate to bacterial growth and
treatment effectiveness. The California study
includes two systems; one providing full treatment
and the other using only disinfection. A manual on
treatment modification an distribution system
maintenance will be the final output of the field
and laboratory studies being conducted by the
University of Missouri on corrosion related to
microbial growth and sediment accumulations in
water mains. An in-house task is also studying the
interactions between microbial activities and
water main deposits. Tubercle samples from eight
different systems have been chemically analyzed
and evaluated for bacterial growth enchancement.
Electron micrographs of some of these sediments
have demonstrated bacterial survival and
protection in the interstices. Two other in-house
tasks are attempting to identify the microf lora of a
finished water distribution system. The occurrence
of pigmented organisms, their disinfection
resistance, and population changes during
treatment are being emphasized.
REFERENCES
1. Allen, M.J., EVALUATING THE MICROBIAL QUALITY OF POTABLE WATER, Presented at Evaluation
of the Microbiological Standards for Drinking Water. Office of Water Supply, U.S. EPA, Washington,
D.C., April 13-14, 1977 (In Press).
2. Allen, MJ. and Geldreich, E.E., DISTRIBUTION LINE SEDIMENTS AND BACTERIAL REGROWTH,
Proceedings AWWA Water Quality Technology CONFERENCE, December 1977, Kansas City,
Missouri, Section 3B-1, pp. 1-6.
3. Geldreich, E.E., Allen, M.J., and Taylor, R.H., INTERFERENCES TO COLIFORM DETECTION IN
POTABLE WATER SUPPLIES, Presented at Evaluation of the Microbiological Standards for Drinking
Water. Office of Water Supply, U.S. EPA, Washington, D.C., April 13-14, 1977 (In Press).
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4. Nash, H.D., SAMPLE COLLECTION AND HANDLING, Presented at Evaluation of the Microbiological
Standards for Drinking Water, Office of Water Supply, U.S. EPA, Washington, D.C., April 13-14,1977
(In Press).
5. Lee, S.H., O'Connor, J.T., and Banerji, S.K., BIOLOGICALLY MEDIATED DETERIORATION OF WATER
QUALITY IN DISTRIBUTION SYSTEMS, Proceedings of 5th Annual A WWA Water Quality Technology
Conference, Kansas City, Missouri (1977).
6. Engelbrecht, R.S. and Haas, C.M., ACID-FAST BACTERIA AND YEASTS AS DISINFECTION
INDICATORS: ENUMERATION METHODOLOGY, Proceedings of 5th AnnualAWWA Water Quality
Technology Conference, Kansas City, Missouri (1977).
POINT-OF-USE TREATMENT DEVICES
Laboratory evaluations of point-of-use carbon
filters were initiated early in fiscal year 1978 in
response to considerable consumer interest and
requests for technical assistance from both the
Office of Drinking Water and the Officeof Pesticide
Programs. Five different carbon filters have been
tested using Cincinnati tap water an a timed
sequential flow through the testing apparatus.
Several filters have also been installed on
fountains in the EPA-Cincinnati research facility.
Weekly samples have been evaluated for Standard
Plate Count, trihalomethan concentrations, total
organic carbon levels, and free chlorine residual.
Generally, filter efficacy is dependent on flow.
Rapid, high volume flow prevents bacterial build-
up on the carbon, but also precludes effective
removal of the chemical contaminants. Low flow
results in more effective removal, but allows
significant bacterial growth in the filter. Several
more filters will be evaluated. Also, assistance has
been provided to the Office of Drinking Water on
initiating a contract to evaluate a large number and
variety of these home use devices.
METHODS DEVELOPMENT
Recent developments in the field of water
treatment have indicated that some organic
compounds in finished water can react with
chlorine to form carcinogenic compounds. As a
result, there has been a trend toward modifying
potable water treatment practices to reduce the
potential for formation of such carcinogenic
compounds. However, changes in treatment
technology may alter the protective barrier
provided by maintenance of a free chlorine
residual in the distribution system. If this
protective barrier is thus reduced, the need for
rapid bacteriological monitoring or detection
systems and for emergency treatment technology
will be mandatory.
Research is in progress to examinetheuseof the
firefly luciferase adenosine triphosphate (ATP)
assay for monitoring the concentration of bacteria
in distribution system water. Successful
development of this technique would permit
bacteria, to be concentrated from a sample volume
as large as 60 liters, followed by extraction and
measurement of bacterial ATP, all in a total time of
one hour or less. The key to the success of the ATP
assay as a semi-automated or an automated test
depends on development of a reliable
concentration method that can be coupled to an
existing in-line ATP extraction procedure. This
assay could provide an excellent tool for quality
control of the treatment process and for following
the bacteriological quality of water at various
points in the distribution system.
The need to examine samples of treated drinking
water larger than two ml when determining the
total bacterial count requires the use of a
membrane filter standard plate count procedure.
This laboratory has now developed medium
suitable for membrane filter work and forthcoming
publication of the method will allow other
interested users to implement it and evaluate its
usefulness.
Efforts have been continued in the development
of a rapid quantitative 14C-radiometric procedure
for detection of fecal coliform bacteria in water.
Primary emphasis has been given to establishing
the precision and reproducibility of the 14C-
mannitol method using water samples from
various surface sources. Other experimental work
compared 14CO2 release from 14C-mannitol
(uniformly labeled) and with 14C-lactose (uniformly
labeled). The use of the '4C-mannitol method
proved better in the short time frame (maximum 6
hours) established for the procedure. All work to
date indicates that a direct relationship exists
between 14CO2 release and fecal coliform
concentration, but the magnitude of 14C02 release
is variable due to stress, injury and/or other
undetermined factors.
While there has always been concern over the
numbers of bacteria present in potable water, little
interest has been shown in reference to what
specific types of bacteria were present except for
coliforms or enteric pathogens. Recently, interest
in knowing what kinds of bacteria may establish
residence in distribution systems has stimulated
new research. Non-enteric bacteria in sufficiently
high numbers may be important in terms of
interference with detecting the presence of
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coliform bacteria in distribution water. A study has subculture. Special methods for biochemical
been understaken to isolate and identify the non- characterization have been implemented in
coliform bacteria from a portion of Cincinnati's conjunction with the use of commercially available
distribution system. Identification of these bacterial identification systems. Special training
organisms is difficult and has resulted in offered by the Center for Disease Control, Atlanta,
development of a new medium for propogation of Georgia, was also necessary.
the organisms in order to carry them in laboratory
REFERENCES
1. Taylor, R.H. and Geldreich, E.E., STANDARD PLATE COUNT METHODOLOGY: A NEW MEMBRANE
FILTER PROCEDURE FOR POTABLE WATER AND SWIMMING POOLS, Journal of the American
Water Works Assoc. (In Press); presented at the Illinois Section AWWA, March 6-9, 1978.
2. Reasoner, D.J. and Geldreich, E.E., RAPID DETECTION OF WATERBORNE FECAL COLIFORMS BY
14C02 RELEASE, In: Mechanizing Microbiology. A.N. Sharpe and D.S. Clark (Eds.), pp. 120-139,
Charles C. Thomas, Springfield, Illinois, (1978).
3. Geldreich, E.E., MICROBIOLOGY OF WATER, Journal of Water Pollution Control Federation,
50(6): 1319-1348(1978).
4. Geldreich, E.E., BACTERIAL POPULATIONS AND INDICATOR CONCEPTS IN FECES, SEWAGE,
STORMWATER, AND SOLID WASTES, In: Indicators of Viruses in Water andFood,G. Berg (ed.), pp.
51-97, Ann Arbor Science Publishers, Inc., Ann Arbor, Michigan (1978).
5. Reasoner, D. J., MICROBIOLOGY-DETECTION OF BACTERIAL PATHOGENS AND THEIR
OCCURRENCE, Journal Water Pollution Control Federation, 50(6): 1382-1395 (1978).
6. Allen, M. J., MICROBIOLOGY OF GROUNDWATER - 1977 ANNUAL REVIEW OF LITERATURE,
Journal Water Pollution Control Federation, 50(6): 1342-1344 (1978).
7. Seidler, R.J., COMPARATIVE PATHOGENICITY OF ENVIRONMENTAL AND CLINICAL KLEBSIELLA,
(EPA Grantee) Oregon State University and Bagley, ST., Abstract Annual Meeting ASM, No. Q6, p.
262, Health Laboratory Science (In Press).
8. Talbot, H.W. Jr., Yamamoto, O.K., and Seidler, R.J., TRANSFER OF ANTIBIOTIC RESISTANCE BY
KLEBSIELLA IN BOTANICAL ENVIRONMENT, (In Press: Abstract Annual Meeting ASM, 1978).
9. Seidler, R.J., KLEBSIELLEAE IN DRINKING WATER EMANATING FROM REDWOOD TANKS, (EPA
Grantee) Oregon State University, Morrow, J.E., and Bagley, ST., Applied and Environmental
Microbiology, 33:893-905 (1977).
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INTERNATIONAL ACTIVITIES
FOREIGN VISITORS
During FY '77 and '78 the Municipal Environmental Research Laboratory (MERL)-Cincinnati received
52 foreign visitors representing national and local governments, industry, academicandother institutions
from 15 countries. The countries represented by these visitors and the number from each during this
period were: Australia 6; Sweden 6; France 5; Japan 5; Poland 5; Bulgaria4; England4; Italy 3; Portugal 3;
Switzerland 3; Iran 2; Finland 2; Tunisia 2; and one each from Egypt and Germany.
These visitors were interested in all phases of the work in MERL. Quite often other laboratories within
the Environmental Research Center were also visited.
COMMITTEE ON THE CHALLENGES TO MODERN SOCIETY (CCMS)
This NATO-sponsored committee attempts to bring together several countries in various peaceful
endeavors. The Municipal Environmental Research Laboratory has been involved in projects on
wastewater treatment and drinking water supply research. Dr. Robert L. Bunch, WRD, is a member ofthe
Advanced Wastewater Treatment Group and U.S. Representative.
ORD's active participation in CCMS began in January 1973 and is to continue until December 1978.
Yearly workshops are held to provide various technical discussions of wastewater technology and serve to
acquaint all participants with the research going on in member countries.
Two projects were conducted, one on advanced treatment of wastewater by physical-chemical
processes and one on the use of pure oxygen in activated sludge trpilot plant at Wuppertal.
The last meeting of the delegates was in London on June 21, 1 978. The draft final report was reviewed
and all comments resolved. The report will be published by December 1978. This will complete the task of
the Advanced Wastewater Treatment Cbmmittee.
PILOT STUDY ON DRINKING WATER STUDIES
Gordon G. Robeck is the MERL representative for the CCMS drinking water project which held its first
meeting in April 1977 in Brussels, Belgium. Follow-up meetings took place in October 1977 in London,
JAPAN 5
FINLAND 2
SWEDEN 6
ENGLAND 4<|j3ERMANY 1
FRANCE 5|SWITZERLANP_3|POLAND 5
PORTUGAL SJJj™^^^^^
TUNISIA2f^f\fS^!llBULGARIA 4
AUSTRALIA 6
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England in April 1978 in Bonn, West Germany, and in September 1978 in Karlsruhe, West Germany.
The objectives of the pi lot study are to achieve a better understanding of:(1) the drinking water problems
shared by industrialized countries, (2) solutions to these problems now available, and (3) potential
problems for which solutions are currently not available (except, perhaps, a prohibitive costs).
Topics to be included are analytical chemistry, treatment technology, sampling, water contaminants
and their health effects, water reuse and ground water protection. Results will be in the form of reports
and international conferences and direct meetings with responsible authorities. The study is expected to
be completed in the Spring of 1979 with the meeting in Reston, Virginia on the subject Adsorption
Techniques in Drinking Water Treatment.
PUBLIC LAW (PL) 480 PROJECTS
Under PL 480, U.S. counterparts in foreign countries are being used to finance projects designed to
advance scientific and technical research in the particular country as well as in the U.S. From MERL
project officers supervise investigations relating to the identification and solution of environmental
problems.
TITLE: Water Reclamation and Useful Utilization of Sewage Solid Waste
LOCATION: University of Karachi, Karachi, Pakistan
GRANT PERIOD: October 1, 1976 to December 21, 1980
PRINCIPAL INVESTIGATOR: Dr. M. Zain-ul-Abedin
PROJECT OFFICER: Robert L. Bunch, MERL-Cincinnati, WRD, TPDB
(Phone: 684-7655)
TITLE: Investigations of BiodegradabiHty and Toxicity of Organic Compounds
LOCATION: Institute of Meteorology and Water Economy, Warsaw, Poland
GRANT PERIOD: March 1, 1975 to February 28, 1978, Extended to February 28, 1979
PRINCIPAL INVESTIGATOR: Dr. Eng. Jan Dojlido
PROJECT OFFICER: Robert L Bunch, MERL-Cincinnati, WRD, TPDB
(Phone: 684-7655)
6th U.S./JAPAN CONFERENCE ON SEWAGE TREATMENT TECHNOLOGY
Many of the problems of waste treatment are common among the highly-developed countries of the
world. Since 1971, the United States and Japan have shared wastewater treatment technology through a
cooperative agreement. The agreement has proven to be mutually beneficial, and has promoted
technology transfer to support both countries' extensive research programs. The cooperative agreement
has resulted in a series of conferences held at approximate 18 month intervals. During 1978 the 6th
Conference was held from October 30 through November 3.
On October 30 and November 1, members of the U.S. and Japanese teams convened at the
Environmental Research Center in Cincinnati to hear technical presentations. Representatives of the
Japanese team presented papers on nitrogen control and removal, sewage sludge de-watering and
incineration, use of pure oxygen, color removal of dyeing wastewater and automatic water quality
monitoring equipment. The United States team presented papers on sludge treatment, instrumentation
and automation, and the programs of the Ohio River Valley Water Sanitation Commission (ORSANCO).
On November 2 and 3, the conference reconvened in Washington, D.C. at the EPA Waterside Mall. The
theme shifted from scientific to institutional, fiscal and organizational problems of mutual interest. The
Japanese team presented papers on institutional structures, sewage works financing, sewer use charge
systems, automatic control systems and activities of the Japan Sewage Works Agency. The U.S. team
presented papers on recent legislation amendments, the construction grants program, program planning
and implementation in Washington, D.C. and Virginia and pretreatment standards.
The Chairman of the 6th Conference is Mr. F.M. Middleton, Senior Science Advisor, MERL. He is also
Head of the Cincinnati U.S. Delegation. Dr. T. Kubo is Co-Chairman of the Conference and Team Leader,
Vice-President, Japan Sewage Works Agency.
FOREIGN TRAVEL AND MEETINGS ATTENDED
Dr. Robert L. Bunch
In October 1977 trips were made to Warsaw and Katowice, Poland, to monitor PL 480 projects and to
attend the World Conference of the Soap and Detergent Association at Montreux, Switzerland.
Monitored research project PL 480 at University of Karachi, Karachi, Pakistan on June 4-10, 1978.
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June 11 -17, 1978, attended the IAWPR 9th International Conference on Water Pollution at Stockholm,
Sweden.
Attended the regularly scheduled NATO/CCMS committee meeting on Advanced Wastewater
Treatment in London, June 21, 1978. The draft report of this committee was reviewed and cleared by the
delegates. The report finishes the work of this committee.
As a team member two papers, "Wastewater and Sludge Research Program", and "Measuring the
Degree of Sludge Stability," were presented October 31, 1978, at the 6th US/Japan Conference on
Sewage Treatment Technology in Cincinnati, Ohio.
On December 5 and 6, 1978, presented two invited papers, "Pilot Plant Development of Ozone
Disinfection" and "The Future Course of Wastewater and Sludge Disinfection," at-the 2nd International
Congress of the Environment, Paris, France.
Francis M. Middleton
In April of 1978 F.M. Middleton visited Tunisia, North Africa at the request of the U.S. State
Department/Agency for International Development to advise the Tunisian Government regarding a new
water pollution control activity and laboratory.
Gordon G. Robeck
In October 1977 to London, England for the NATO/CCMS Pilot Study on Drinking Water Supply
Problems and in October 1978 to Kyoto, Japan to participate in the International Water Supply Congress
Association by representing the USA on virus control, granular activated carbon treatment, and
micropollutant control by oxidants.
Dr. James M. Symons
In April 1978 to Bonn, West Germany for the NATO/CCMS Pilot Study on Drinking Water Supply
Problems and visits to water treatment plants in Dusseldorf, Wuppertal, Siegburg, West Germany.
Jesse M. Cohen
At the invitation of Dr. P.R. Philip of the Ministerede 1 'Environnementet du Cadre de Vie, Paris, France,
two papers were presented to the 2nd International Congress of the Environment on December 5 and 6,
1978. The papers were entitled "Observations on Physical-Chemical Treatment in the USA" and "Pilot
Plant Investigations on Physical-Chemical Treatment."
Alan A. Stevens
In September 1978 to Karlsruhe, West Germany for the NATO/CCMS Pilot Study on Drinking Water
Supply Problems. He presented a paper there at the Oxidation Techniques in Drinking Water Treatment
Session on Unwanted Byproducts of Chlorination. On that same visit, Mr. Stevens also visited water
treatment plants in Zurich, Switzerland; Dusseldorf, Wupertal, and Mulheim, West Germany and
Rotterdam, Holland and research institutes in Karlsruhe and Essen, West Germany; Dubendorf-Zurich,
Switzerland; and Hague, Jutphass and Rtjswijk, the Netherlands; and Medmenham, England.
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