EPA-660/2-74-094
JANUARY 1975
Environmental Protection Technology Series
Pollution Control Technology for
Pesticide Formulators and Packagers
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Ag'
Corvallis Oregon 97330
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RESEARCH REPORTING SEKIES
Research reports of the Office of Research and Development,
U.S. Environmental Protection Agency, have been grouped into
five series. These five broad categories were established to
facilitate further development and application of environmental
technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in
related fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY STUDIES series. This series describes research
performed to develop and demonstrate instrumentation, equipment
and methodology to repair or prevent environmental degradation from
point and non-point sources of pollution. This work provides the
new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval does
not signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
recommendation for use.
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EPA-660/2-74-094
January 1975
POLLUTION CONTROL TECHNOLOGY FOR PESTICIDE
FORMUIATORS AND PACKAGERS
by
Mr. Thomas L. Ferguson
Project Officers
Dr. Robert R. Swank, Jr.
Southeast Environmental Research Laboratory
National Environmental Research Center
College Station Road
Athens, Georgia 30601
and
Mr. David L. Becker
Effluent Guidelines Division (WH-452)
Office of Water and Hazardous Materials Programs
Washington, D.C. 20460
EPA Grant Number R801577
Program Element 1BB036
ROAP 21AZR, Task 006
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
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ABSTRACT
The pesticide formulation and packaging industry transforms bulk pesticidal
chemicals (active ingredients) into packaged, ready-to-use forms for sale
to the consumer. Most pesticides are formulated in plants completely separate
from the site of active ingredient manufacture.
The industry is structured into three categories: pesticide-producer formu-
lators, independent formulators, and small packagers for whom pesticide for-
mulation is usually a minor part of their operation.
About 32,000 formulated products are federally registered to approximately
3,400 companies for interstate sale. Over two-thirds of the products are
registered to companies marketing five or fewer pesticide products. Most
pesticide products, however, are apparently formulated in the 200 to 300
large formulation plants located throughout the country.
Techniques currently used to dispose of process wastewater include evaporation,
landfill disposal, and contract disposal services. Pretreatment of process
wastewater before discharge into municipal systems is not universally practiced,
and the techniques currently being used are generally inadequate to meet in-
creasingly strict standards.
The best practicable wastewater treatment technology appears to be complete
evaporation. Alternatively, partial evaporation with disposal of the con-
centrate in an approved landfill can be used. Air pollution resulting from
these practices, however, has not been evaluated. The best available treat-
ment technology appears to be a pretreatment-filtration-adsorption process
now in the development phase.
Additional research on wastewater composition, evaporative transport of
pesticides, and the demonstration of the pretreatment-filtration-adsorption
process is needed.
This report was submitted in fulfillment of Grant No. R801577 under the
sponsorship of the U.S. Environmental Protection Agency, Office of Research
and Development. Work was completed as of July 1973.
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CONTENTS
Abstract
List of Figures vii
List of Tables viii
Acknowledgments *-x
Sections
I Conclusions 1
II Recommendations 3
III Introduction 5
Background 5
Study Objectives and Approach 6
IV Industry Characterization 9
Pesticide Formulations 9
Formulation Processes 15
Industry Structure 20
V Wastewater Characterization 31
Water Uses and Wastewater Sources 31
Wastewater Characteristics 35
VI Current Wastewater Treatment Practices 41
Evaporation 41
Sewer Systems 45
Landfills 45
Contract Disposal 46
Activated Carbon Adsorption 46
Incineration 46
Miscellaneous Pretreatment Processes 47
111
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CONTENTS (Continued)
Page
VII Best Treatment Technologies 49
Best Practicable Technology 49
Best Available Technology 50
VIII Research and Development Needs 55
Wastewater Characterization 55
Evaporative Wastewater Treatment Systems 55
Pretreatment-Filtration-Adsorption System 56
Detoxification Processes 56
IX References 57
Appendix A - Formulation Plant Case Studies 63
Appendix B - National Agricultural Chemical Association 89
(NACA) Waste Disposal Manual
Appendix C - Classification of Pesticidal Chemicals 143
Appendix D - Estimated Costs for Best Treatment 147
Technologies
IV
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FIGURES
No.
1 Liquid Formulation Unit 16
2 Typical Sulfur Grinding Unit 18
3 Process for Formulating Dust 19
4 Distribution of Registrants by Number of Federal
Registrations 21
5 Distribution of Registrants by Number of State
Registrations 22
6 Large Formulation Plant Locations 25
7 Geographical Distribution of Companies Holding 26
Federal Registrations
8 Distribution of Federal Registrations by Company 27
Location
9 Product Distribution for Large Formulation Plants 28
10 Distribution of Plants by Age 30
11 Formulation Plants Using Evaporative Treatment Systems 42
12 Mean Annual Inches of Lake Evaporation 43
13 Mean Annual Inches of Precipitation 44
14 Evaporative Wastewater Treatment 51
15 Pretreatment-Filtration-Adsorption System 53
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TABLES
No. Page
1 Composition of a Sample Etnulsifiable Concentrate
Formulation 10
2 Diluents Used in Insecticide Formulations 11
3 Pesticidal Product Registrations for Companies
Headquartered in Representative States 13
4 Classification of Industrial Wastewater Characteristics 38
5 Guidelines for Pesticide Content of Water 39
6 Pretreatment Processes and Their Protective Functions 48
VI
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ACKNOWLEDGMENTS
This study was conducted by Midwest Research Institute, as a subcontractor
to the National Agricultural Chemicals Association, through EPA Grant No.
R801577. Members of the project team were Mr. Thomas L. Ferguson, who
served as Project Leader, Dr. Alfred E. Meiners, and Dr. Edward W. Lawless
of MRI; Mr. William L. Bell, Industrial Consultant; Dr. Frank C. Fowler,
Research Engineers, Inc.; and Dr. Rosmarie von Rumker, RvR Consultants.
Dr. A. D. McElroy was administratively responsible for this program, which
was conducted in the Physical Sciences Division of MRI, Dr. H. M. Hubbard,
Director.
The study was made possible by the cooperation of two interested groups.
The NACA membership, working through its Committee on Agricultural Chemical
Environmental Quality, Mr. Robert E. Naegele, Chairman, provided much of the
data that are contained in this report. The U.S. Environmental Protection
Agency was quite helpful at both the regional and national levels in pro-
viding additional data on federal pesticide registrations and the operations
of the pesticide formulation industry. Mr. David L. Becker, Effluent Guide-
lines Division, EPA Project Officer for the study, has aided in the coordi-
nation of the efforts of these two organizations. Dr. Robert R. Swank, Jr.,
of the Southeast Environmental Research Laboratory, EPA Co-Project Officer
for this study, aided in providing technical input on possible treatment
and disposal practices and in reviewing the project results.
Vll
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SECTION I
CONCLUSIONS
The following conclusions apply to the pesticide formulation and packaging
industry, and to the applicable wastewater control technologies. These
conclusions are ordered according to their decreasing importance.
1. The best practicable control technology currently available for most
plants in the industry appears to be an evaporative system having no effluent.
For those plants that cannot effect complete evaporation of their process
wastewater, partial evaporation in conjunction with disposal in an approved
landfill appears to be the best alternative. A major limitation to the use
of evaporative systems, however, is the possible pollution of air by toxic
chemicals through various water-to-air transfer mechanisms.
2. The best available treatment technology appears to be a three-step
process: (a) pretreatment (neutralization, precipitation, and/or deemulsi-
fication); (b) filtration; and (c) adsorption (activated carbon and/or resin).
The specific treatment requirements can be expected to vary with the indi-
vidual plant sites.
3. Only one formulation plant has been identified that is currently using
wastewater treatment technology closely approximating this definition of
best available technology. This plant's treatment process is still in the
pilot-plant phase of development.
4. The expense of installing and operating equipment that is equivalent to
best available technology as defined above, would have a significant impact
on the capital investments required for many formulation plants.
5. Some plants are currently operating with no discharge of process waste-
waters. By conservative water usage and improved operating and housekeeping
practices, most plants can either eliminate or significantly reduce the
volume of process wastewater generated.
6. Pretreatment practices that are now being used to process wastewaters
before discharge into municipal systems appear to be.generally inadequate.
7. The majority of pesticidal chemicals are formulated in 200 to 300 formu-
lation plants located throughout the United States. Many of these plants
produce 20,000,000 to 40,000,000 Ib of formulated material per year.
8. The majority of pesticide registrations, both State and Federal, are held
by small companies. Over two-thirds of these registrations are held by com-
panies having five or fewer pesticidal products. The majority of these prod-
ucts are apparently formulated under contract in the 200 to 300 largest for-
mulation plants.
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SECTION II
RECOMMENDATIONS
The fundamental limitation in attempting to evaluate treatment technology
for pesticide formulation and packaging wastewater is the lack of adequate
quantitative and qualitative data. An overall recommendation, therefore,
is that research and development studies be undertaken that will provide the
necessary data. Recommendations for specific areas of study to provide these
data follow. These are listed in their chronological order of need.
1. Studies should be made to characterize formulation wastewaters in terms
of volumes, toxicant concentrations and overall pollution parameters. Pes-
ticide formulation is largely a seasonal industry; for this reason, the
wastewater characterization studies should be conducted for representative
sites over a complete production season.
2. The potential for polluting air by evaporation of low solubility con-
taminants, such as pesticides, from water bodies is one of the major uncer-
tainties in the use of evaporative treatment systems. Determination of the
air pollution resulting from evaporative wastewater treatment systems is
urgently needed. This study should be conducted concurrently with the char-
acterization of formulation wastewater, and should also cover an entire
production season.
3. The pretreatment-filtration-adsorption system, identified as potentially
the best treatment system available for use on formulation wastewater, has
not been fully demonstrated in terms of both technological performance and
economic viability. The performance of this system should be evaluated,
as well as modifications that would make it more efficient.
4. Longer-term studies should be initiated to identify effective methods
for detoxifying the pesticidal chemicals in formulation wastewaters. The
application of biological as well as chemical detoxification processes to
formulation wastewaters should be included.
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SECTION III
INTRODUCTION
The need to control potentially polluting emissions from agricultural chemi-
cal plants has been recognized for a number of years. One of the first
sources of information on control techniques applicable to pesticide manu-
facturing and formulating facilities was a manual developed by a special
National Agricultural Chemicals Association (NACA)-Industry Committee (the
Grady Committee), and published by the NACA in 1965. This publication,
"Manual on Waste Disposal,11!./ has been widely used by the industry, and has
become known as the "Grady Waste Disposal Manual."
The NACA manual has been a useful guide to wastewater disposal because of
its general descriptions of wastewater treatment techniques, as well as of
disposal methods for specific classes of pesticides. However, most of this
information is addressed to disposal of wastewaters from pesticide manufac-
turing facilities or manufacturing-formulation complexes, rather than waste-
waters from a separate formulation plant. Neither the "Grady Manual" nor
any other available publication provides sufficient information to enable
pesticide formulators and packagers to comply with the new system of national
effluent limitations and performance standards. Because of this lack of in-
formation this study has been made, utilizing a research grant from the U. S.
Environmental Protection Agency (EPA), to document information on control
technology applicable to pesticide formulating and packaging plants.
Background
In 1965, the NACA published the "Grady Waste Disposal Manual" to provide
"guidelines which might be followed in the disposal of waste from pesticide
manufacturing and formulating operations.1—' Although this manual contains
much pertinent information, it is of limited usefulness in that it does not
address the pesticide formulator as a specific audience. In fact, this
document is now considered to be quite out of date, and is no longer in print.
In 1970, the Environmental Quality Committee of the NACA initiated efforts
to provide a more current source of waste treatment information applicable
to formulation plants. During 1970 and 1971, their work yielded draft re-
visions of many sections of the original manual, as well as the development
of new sections for inclusion in an updated edition. It was later concluded,
however, that the scope of revisions required was larger than the NACA could
provide through its committee systems. One major element that expanded the
disposal manual's scope over that which existed when the original edition
was developed has been new water pollution control legislation.
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The Water Pollution Control Act of 197Z?/ outlines two national goals:
(1) "by July 1, 1983, wherever possible, water that is clean enough for
swimming and other recreational use, and clean enough to protect fish, shell-
fish and wildlife"; and (2) "by 1985 no more discharge whatsoever of pollut-
ants into the Nation's waters."3/ To meet these goals, a series of actions
is being taken by the EPA.
Limitations are being established on the maximum amounts of pollutants that
can be discharged into a water body. To meet these effluent limitations,
"best practicable" and "best available" water pollution control technologies
are being defined on the basis of cost, age of the industrial facility,
processes used, and the environmental impact of applying these controls.
Industries must meet effluent limits equivalent to "best practicable" tech-
nology by 1 July 1977, and must meet effluent limitations reflecting "best
available" technology by 1 July 1983. Where technically and economically
achievable, the national goal is to eliminate pollutant discharge by 1 July
1985.
In addition, industrial discharges into publicly-owned sewage treatment plant
will also be subject to effluent limitations. Pretreatment requirements,
where specified, will take effect no later than May 1974 for new industrial
sources, and no later than July 1976 for existing industrial facilities.
Study Objectives and Approach
The overall objectives of this study were to identify the "best" wastewater
treatment technologies applicable to pesticide formulation plants, and to
provide the pesticide formulation industry with a source of practical infor-
mation on how to comply with effluent limitations.
Specific objectives were:
* characterization of the industry,
• characterization of the wastewater produced,
• assessment of applicable treatment technology,
• identification and assessment of best practicable,
best available, and pretreatment technologies, and
• identification of research and development needs.
A dual approach was used to obtain the information needed to meet these ob-
jectives. The formulation industry, through the NACA membership, was sur-
veyed to characterize its operation and identify plants already using good
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waste treatment practices. Key formulation plants were then selected for
detailed case studies (see Appendix A). Concurrently, local, State, and
Federal agencies were contacted to obtain available data on effluent char-
acteristics and plant operations.
As an additional part of this study, data were compiled that had been gen-
erated to update the "Grady Disposal Manual," and integrated into the for-
mat of the original document. The updated manual has been included as
Appendix 8.
The scope of this study did not include provisions for analyses of plant
waste streams, either to determine stream parameters, or to verify the re-
ported effectiveness of treatment systems. Data are therefore limited to
those made available by individual companies, found in the open literature,
or obtained from local, State, or Federal agencies.
In addition, this study was not conducted as an official part of the EPA
program to establish suggested effluent-limitation guidelines and standards
of performance for specific industry categories, e.g., for pesticide formu-
lators. Many companies have chosen not to make certain confidential infor-
mation available.
The results of this study are presented in the following five sections:
Industry Characterization; Wastewater Characterization; Current Wastewater
Treatment Practices; Best Treatment Technologies; and Research and Develop-
ment Needs. These sections parallel the five specific objectives outlined
above.
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SECTION IV
INDUSTRY CHARACTERIZATION
Pesticide formulation and packaging is the segment of the agricultural chem-
ical industry that transforms bulk, highly concentrated active ingredients
(technical pesticide) into convenient-to-use, effective forms ready for sale
to the ultimate user. As the name of the industry indicates, two major
operations are required to effect this transformation. The pesticidal mate-
rials must first be blended (formulated) with the necessary additives and
inert carriers, and then packaged in appropriate containers.
Generally, the term "formulation industry" is used to include both of these
operations because they are sequential steps normally conducted in the same
plant. This meaning of the term is used throughout the report.
It was necessary to characterize the formulation industry before a meaning-
ful assessment of pollution control technology could be made. Major con-
siderations in the characterization were (1) what types of products are
made, (2) how these products are manufactured, and (3) how the industry is
structured. These considerations are discussed in the following three sub-
sections.
Pesticide Formulations
Pesticidal chemicals (active ingredients) are normally manufactured in high
concentration (80 to 99+70 • Most active ingredients, however, cannot be
used in their manufactured (technical) concentrations without being further
processed into other forms. The usable forms (formulations) of pesticides
must be biologically effective, as well as safe for the applicator to handle
and use. These characteristics are obtained by dilution of the technical
active ingredient with inert materials and conversion to appropriate physi-
cal forms designed for a particular method of application and end use.
The ultimate tests for a pesticide formulation are its effectiveness on the
intended target, and the longevity of that effectiveness in storage. Major
development work is often required to find a combination of ingredients
that will meet these requirements. This effort is reflected in part by the
dollar investment required to develop new pesticide products.-tl—'
For many pest control situations, complex formulations of active ingredients,
solvents, stabilizers, synergists, emulsifiers, etc., are required..§/
Table 1, for example, lists the ingredients of one formulation that at one
time was extensively used. The variety in formulation composition that is
produced to meet specific applications and customer requirements is illus-
trated by Table 2. This table lists 25 potential diluents for use in dust
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TABLE 1
COMPOSITION OF A SAMPLE EMULSIFTABLE CONCENTRATE FORMULATION^!/
Weight 7,
Active Ingredients:
Toxaphene (90%) 42.1
DDT (100%) 18.9
Methyl Parathion (80%) 11.8
Solvents:
Tenneco 500 10.6
HAN 132 10.6
Stabilizer:
Epichlorohydrin 1.0
Emulsifiers:
ATLOX 3404 2.5
ATLOX 3403F 2.5
100.0
10
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TABLE 2
II
DILUENTS USED IN INSECTICIDE FORMU1ATIONS-
Trade Name
Attaclay
Harden Clay
No. 475 Bentonite
Cab-0-Sil
Celite
Clatal
Continental Clay
Dicalite 109-3
Diluex
Frianite M3X
Glendon Pyrophyllite
6 J Gray Talc
Hi-Sil 233
Hi-Sil 266X
Micro-Cel
Narvon IF2
Pikes Peak Clay
Purecal 0
Pyrax ABB
No. 29 Pyrophyllite
"Sierra Cloud" Talc
"Sierra White" IR
Silene EF
Zeothi 60
Zeosyl
Type
Attapulgite
Kaolinite
Montmori11onoid
Synthetic
Diatomite
Talc
Kaolinite
Diatomite
Attapulgite
Diatomite
Pyrophyllite
Talc
Synthetic
Synthetic
Synthetic
Kaolinite
Montmorillonoid
Calcium Carbonate
Pyrophyllite
Pyrophyllite
Talc
Talc
Synthetic
Synthetic
Synthetic
7.5-9.0
4.0-5.0
8.5-9.5
4.5-6.0
6.0-7.0
8.5-9.0
4.5-5.5
7.0-8.5
7.5-9.0
5.5-6.5
6.0-7.0
8.5-9.0
6.5-7.5
5.5-7.0
8.0-10.0
5.0-5.5
4.5-5.5
8.0-8.5
6.5-7.0
5.5-6.0
8.5-9.5
8.5-9.5
9.5-10.0
6.5-7.5
6.5-7.5
a/ pH was determined on 5% by weight suspension in distilled water or
from producer's literature.
11
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formulations of one insecticide.-' The lists of potential solvents and
miscellaneous adjuvant chemicals are of comparable length.
Many factors are involved in the optimization of a formulation. Because
of the complexities of these factors, trial and error techniques are still
important elements in the development of successful formulations.—' The
composition of a formulation, except for the active ingredients and inert
carrier or solvent, therefore, is usually considered confidential.
The number and types of pesticidal products sold, as well as the major type
of formulations, are briefly discussed in the following section. More de-
tailed information is available in a number of references for those requir-
ing more specific data.9*10'
Number of Products: The number of pesticide formulations produced and sold
in the United States is difficult to determine accurately. Estimates have
been made that as many as 900 pesticidal chemicals are formulated into over
60,000 products.—/ A more recent survey identified 550 pesticidal chemi-
cals that are currently or have recently been commercially available in the
United States.i2/
Accurate data are available on the number of pesticidal products having
Federal registration for interstate sale. On 31 March 1973, there were
31,898 products having current Federal registration.!^:'
Comparable data on pesticidal formulation registered for intrastate use,
which are not included in the Federal registration listing, are not avail-
able. Table 3, however, summarizes available data on several key states.
The number of Federally registered products are compared to the number of
intrastate registrations for companies headquartered within the respective
states. These data indicate that there are several thousand pesticide for-
mulations marketed in addition to the nearly 32,000 sold under Federal
registration.
Emulsifiable Concentrates: Emulsifiable concentrate (EC) formulations are
solutions of active ingredients and emulsifiers in a solvent. These formu-
lations are diluted with water or oil before application. Concentrations
are typically 15 to 50% for a single active ingredient, to as high as 80%
for formulations containing an active ingredient mixture. The concentration
of emulsifiers is generally 5% or less.
Organic solvents are used for most emulsifiable concentrate formulations.
Solvents commonly used include deodorized kerosene, xylenes, methyl isobutyl
ketone, and amyl acetate.—' The specific solvent selected for use depends
on many factors, including solvency, specific gravity, flash point, safety
to plants and animals, volatility, compatibility, odor, corrosiveness, and
cost.M'
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TABLE 3
PESTICIDAL PRODUCT REGISTRATIONS FOR
COMPANIES HEADQUARTERED IN REPRESENTATIVE STATES
Number of Registrations
State Registrations
State Federal^/ Statefr-/ Not on Federal Listing
Arizona 123 535
California 2,790 6,234
Louisiana 238 341
Missouri 2,130 - 132
New Jersey 2,482 - 86
a/ Listing as of March 31, 1973.
b/ Based on 1972 data.
Water is used as the solvent for some of the water-soluble pesticides. The
use of water is limited, however, and normally only certain herbicides are
formulated with a water base.
Powders: Wettable or water-dispersible powders are mixtures of active in-
gredients, inert carriers, surfactants, and adjuvants that can be suspended
in water for application. These powders generally contain a high concen-
tration of active ingredient (15 to 95%), with 1 to 57. concentration of sur-
factant to improve wetting and suspendibility characteristics.
Soluble powders are similar to wettable powders except that they will com-
pletely dissolve in the appropriate diluent used in spraying. Normally,
this diluent is water.
Dusts: The active ingredient concentration in dust formulations is usually
low (0.1 to 2070), and therefore, the toxicity of these formulations is
relatively low.
Dusts have long been used because they are relatively inexpensive and simple
to apply. In the past few years, however, it has become a less important
formulation because of its inherent dependence on climatological factors
that cause variability in performance, as well as problems with drift.±Z'
13
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The physical properties of dust formulations are determined by the proper-
ties of the carrier used and the particle size to which the formulation is
ground. Some of the more commonly used carriers are organic flours, sulfur
silicon oxides, lime, gypsum, talc, pyrophyllite, bentonites, kaolins,
attapulgite, and volcanic ash (see Table 2, page 11). Selection of the
carrier is critical, and is based on compatability with the active ingredi-
ent, particle size, abrasiveness, density, absorbability, wettability and
cost.
These finely ground dry formulations typically contain active ingredient
and inert carrier without the adjuvant chemicals found in powders. Dust
formulations are directly applied without further dilution.
Granules: Granules are prepared by the impregnation of active ingredient
on inert granular carriers such as clay, venniculite, bentonite, sand,
ground corncobs, carbon or diatomaceous earth. The granules are uniform
in size, ranging from 15 to 60 mesh (15 to 30, 24 to 48, or 30 to 60 mesh)
in diameter. The content of fine particles is tightly controlled in order
to avoid dusting during application.
Granular formulations have advantages in that they avoid the problem of
drift, and the rate of toxicant release can often be controlled by changing
the ingredients of the formulation. The size of the inert granule, which
is carefully controlled, also influences the redistribution of the active
ingredient. This formulation is widely used for soil applications and is
applied without further dilution.
Aerosols: Aerosol formulations normally contain low concentrations (less
than 2%) of active ingredients in a suitable solvent solution with the
necessary adjuvants. Solvents commonly used are organics, such as deodor-
ized kerosene, and water. A wide range of special purpose additives may
be included, depending on the intended use of the aerosol; for example,
chlorbisan in a pet spray to suppress odor; copper oleate in some roach
and ant sprays to prevent mildew; and isoparaffinic-based oil in livestock
face fly sprays for the safety of the animals' mucous membranes.!§/ Syner-
gistic chemicals are also commonly used, such as piperonyl butoxide, sulf-
oxide and propyl isomer. Pyrethrins are the active ingredients most com-
monly used.
Although millions of cans of pesticide aerosols are used each year in the
United States, less than 1% of the total quantity of pesticidal active in-
gredients used is formulated in this manner.
Miscellaneous Formulations: In addition to these major pesticide formula-
tions, a wide range of smaller volume products are manufactured. These
other forms include baits (strips, grain, cubes, etc.), pastes, vapor and
smoke generators, impregnated fertilizer, tablets, and treated seed.
14
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Formulation Processes
Most pesticides are formulated in mixing equipment that is used only to pro-
duce pesticide formulations. The most important unit operations involved
are dry mixing and grinding of solids, dissolving solids, and blending.
Formulation systems are virtually all batch mixing operations. Formulation
units may be completely enclosed within a building, or may be out in the
open, depending primarily on the geographical location of the plant.
Individual formulation units are normally not highly sophisticated systems
that require design and construction by an outside engineering firm.
Rather, they are comparatively uncomplicated batch-blending systems that
are designed to meet the requirements of a given company, location, rate
of production, and available equipment. Production units representative
of the liquid and solid formulation equipment in use are described below.
Liquid Formulation Units: A typical liquid unit is depicted in Figure 1.
Technical pesticide is usually stored in its original shipping container
in the warehouse section of the plant until it is needed. When technical
material is received in bulk, however, it is transferred to holding tanks
for storage. The technical material is transferred (frequently by gravity)
to a scale, where the proper quantity is weighed out for a batch. The tech-
nical material is then pumped into a batch mixing tank. This tank is fre-
quently an open-top vessel with a standard agitator. The mix tank may or
may not be equipped with a heating/cooling system. When solid technical
material is to be used, a melt tank is required before this material is
added to the mix tank. Solvents are normally stored in bulk tanks located
well away from the operating area of the plant. The necessary quantity of
an appropriate solvent is either metered into the mix tank, or determined
by measuring the tank level. Necessary adjuvants (emulsifiers, synergists,
etc.) are added directly from their original container to the mix tank
through the open top or a manhole. The components of the formulation are
blended in the mix tank using its agitator and heating/cooling system as
required. From the mix tank, the formulated material is frequently pumped
to a hold tank before being put into containers for shipment. Before being
packaged many liquid formulations must be filtered by conventional cartridge
or plate-and-frame filters.
Air pollution control equipment used on liquid formulation units typically
involves an exhaust system at all potential sources of emission. Storage
and holding tanks, mix tanks, and container-filling lines are normally pro-
vided with an exhaust connection or hood to remove any vapors. The exhaust
from the system normally discharges to a scrubber system or to the atmosphere.
Dusts and Wettable Powders: Dusts and powders are manufactured by mixing
the technical material with the appropriate inert carrier, and grinding this
15
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EXHAUST VENT
HOOD
PESTICIDE
'(55 GAL. DRUM)
SOLVENT STORAGE
•AGITATOR
•MANHOLE
•EMULSIFIER
PRODUCT
{55 GAL. DRUM)-
STEAM
COOLING WATER
FILTER
-C
1
t
| SCALE 1
Figure 1 - Liquid Formulation Uni:
197
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mixture to obtain the correct particle size. Mixing can be effected by a
number of rotary or ribbon blender type mixers. Grinding is done in hammer,
impact, roller or fluid energy (air) mills. As is the case with liquid
formulation units, the exact configuration of a specific dust or powder
unit depends on the production characteristics of the individual plant site.
Sulfur powder can be prepared in a rather simple unit (see Figure 2). Crude
sulfur is transported from storage in open pits or in a warehouse, and
loaded into a feeding hopper which feeds a roller mill. The material is
then finely ground. The combustible nature of sulfur in air requires that
the mill system be blanketed with an inert gas. The milled sulfur then goes
to a cyclone collector from which the finished product is discharged into
holding bins before being packaged.
Some production methods involve the use of a volatile solvent to impregnate
the active ingredient on an inert carrier. After impregnation, the active
ingredient-carrier mixture is ground, separated in a cyclone, and packaged.
One formulation process that has been used for DDT is a good example of
more extensive processing required to produce some products: a two-stage
process is used (see Figure 3). The first part of the process is the initial
grinding of the active ingredient (Figure 3a) with silica. Flakes of tech-
nical material are emptied from bags onto a hopper, conveyed into a crusher,
and mixed with finely ground silica before being pulverized. The coarse
silica-active ingredient mixture is then mixed in a ribbon blender. This
DDT formulation requires aging at this point before further grinding. The
mixture is then fed into a ribbon blender where additional silica as well
as wetting agents are added. This mix is conveyed to a high-speed grinding
mill. A pneumatic system conveys the material to a cyclone separator which
discharges into another blender. The blended material is finely ground by
high-pressure air mill and conveyed to a reverse-jet baghouse that discharges
into another blender. Final air grinding is repeated before the finished
product is packaged.
Air pollution control in dust formulation units is accomplished primarily
by baghouse systems. In some plants, however, water scrubbers are used.
Water requirements for these systems are very low because the scrubbing
water can be largely recirculated.±Z/
Granules: Granules are formulated in systems similar to the mixing sections
of dust plants. The active ingredient is absorbed onto a sized, granular
carrier such as clay or a botanical material. This is accomplished in
mixers of various capacity that generally resemble cement mixers. Ribbon
blenders are not used because they tend to break down the granules.
17
-------
PRESSURE
RELIEF VENTS
CYCLONE
COLLECTOR
FINISHED
PRODUCT
DISCHARGE
RETURN AIR LINE
VENT STACK
INERT GAS INLET
VENT TO
'BAGHOUSE
SEPARATOR
ROLLER MILL
EXHAUSTER
20/
Figure 2 - Typical Sulfur Grinding Unit—
18
-------
f-r
FEED
HOPPER
SILICE
HOPPER
BAGHOUSE
TO
ATMOSPHERE
\ /
\
/
i
!
PI II VFPI 7FR
1
1
DI PMRFP
"N|
(
1
1
BARREL
FILLERS
a) Pretnix Grinding
ATMOSPHERE
r-+
(j ATMOS
TO
ATMOSPHERE
ATMOSPHERE
REVERSE-JET
BAGHOUSE
REVERSE-JET
BAGHOUSE
PREMIXED
MATERIAL
SILICA
WETTING
AGENT
AIR
FINISHED PRODUCT
b) Final Grinding and Blending
Figure 3 - Process for Formulating Dust
19
21/
-------
If the technical material is a liquid, it can be sprayed directly onto the
granules. Solid technical material is usually melted or dissolved in a
solvent in order to provide adequate dispersion on the granules. The last
step in the formulation process, prior to intermediate storage before
packaging, is screening to remove fines.
Packaging and Storage: The last operation conducted at the formulation
plant is packaging the finished pesticide into a marketable container.
This is usually done in conventional filling and packaging units. Frequent
the same liquid filling line is used to fill products from several formula-
tion units; the filling and packaging line is simply moved from one for-
mulation unit to another. Packages of almost every size and type are used,
including 1-, 2-, and 5-gal. cans, 30- and 55-gal. drums, glass bottles,
bags, cartons, and plastic jugs.
On-site storage, as a general rule, is minimized. The storage facility is
very often a building completely separate from the actual formulation and
filling operation. In almost all cases, the storage area is at least lo-
cated in a part of the building separate from the formulation units in orda
to avoid contamination and other problems. Technical material, except for
bulk shipments, is usually stored in a special section of the product
storage area.
A few formulators are able to ship formulated products in bulk containers
to users in their immediate area. This technique, however, is limited to
a few agricultural formulations.
Industry Structure
The formulation industry is such a dynamic one that detailed characteriza-
tion of its organization and operation is difficult. The question, "Who
formulates a given active ingredient, and in what quantity?", will have a
different answer almost every year. Currently, there are about 3,400 com-
panies who have Federal registrations for pesticide formulations. Those
companies range in size from those who have one registered product, to thos<
who have hundreds (see Figure 4). Almost three-quarters of the Federal
registrants, however, have five or fewer registered products. Figure 5
shows the same type of distribution for State registrations, based on the
data available (6 states). The State registration data also indicate a
high concentration of registrants in the one-to-five registration range.
Characteristics that apply to all formulators of pesticides, however, can
be discussed. These include ownership patterns, geographical distribution,
and individual plant characteristics.
20
-------
1400
1200
1000
I 800
0)
t>
o
h»
0)
3
z
600
400
200 -
40.2%
14.6%
10.5%
8.5%
5.6%
4,4%
2.6%
2.0%
3.7%
1.5%
0.9%
1.6%
12345 6-10 11-15 16-20 21-25 26-50 51-75 76-100
Number of Registrations
Figure 4 - Distribution of Registrants by Number of Federal
Registrations
101 and Over
-------
40
30
to
O
O>
V
v
u
£
20
10
4 5 6-10 11-15 16-20 21-25 26-50 51-75
Number of Registrations
Figure 5 - Distribution of Registrants by Number of State
Registrations
76-100
101 and Over
-------
Ownership Patterns: Formulation plants can be categorized into three
groups: the active ingredient producer-formulatorj the independent for-
mulator, and the small packager.
The producer-formulator is also referred to as an integrated producer.
Such a company not only manufactures the pesticidal chemicals, but also
formulates them in its own facilities. Frequently, formulating is done on
the same plant site as the production of the active ingredient. Such for-
mulation plants (i.e., satellite units of a production facility) have not
been included in this study because they have access to waste treatment
facilities and expert advice. Producer-formulator plants may also be lo-
cated away from the production site of the active ingredient, e.g., close
to or within the regions where the company's products are used. These
plants may formulate the company's own products exclusively, or may formu-
late other products on a custom basis, and were included in this study,
although they also usually have the expertise and help of the parent com-
pany to call on if needed.
The independent formulator produces products for sale under his own brand
name and may also formulate products on a contractual arrangement. A num-
ber of the large pesticide manufacturers do not formulate any of their own
products, and are, therefore, prime customers for the independent formulator.
Under contractual agreement, the pesticide manufacturer furnishes the tech-
nology, active ingredient, and operational assistance to the formulator.
The products are then sold under the basic manufacturer's labels. It is not
uncommon for an independent formulator to have this type of contract with
more than one basic manufacturer.
Most independent formulators also have pesticide formulations that they
produce for sale under their own Federal or State labels. Examples of
these operations are the farm cooperatives that formulate and sell pesti-
cides. Products marketed under the formulator's own label can account for
a small part of his production, or it can account for all of it.
In addition to contract formulation for basic active ingredient manufacturers,
the independent formulator frequently has contracts with independent com-
panies to formulate under their private labels. -Most of the products sold
with a department store's label, for example, are formulated under this type
of contract.
The last major category of formulator is the small independent packager for
whom pesticide formulations are only a small part of his business. These
companies typically have one to five Federal or local registrations in their
own name. Many of these small packagers actually formulate their labeled
products in their own facility. A more practical arrangement for many,
however, is to contract with one of the local independent formulators to do
the actual formulating.
23
-------
Geographical Distribution: The locations of large pesticide formulation
plants identified during this study are shown in Figure 6. These plants
were identified from information provided through the NACA as well as from
two earlier studies of the formulation industry323,24 / and do not include
those formulation plants that are integral parts of pesticide manufacturing
facilities.
A more complete picture of the formulation industry, however, can be gained
by noting the numbers and locations of companies holding registrations for
pesticides. Figures 7 and 8 show (a) the states in which corporations are
headquartered who have Federal pesticide registrations, and (b) the number
of Federal registrations, respectively. The significance of these data is
limited because all companies and Federal registrations are shown in the
state in which their headquarters are located. In many cases, and especially
for the large companies, these locations are not sites of formulation plants.
Smaller companies, however, constitute the bulk of the registrants (see
Figures 4 and 5, pages 21 and 22), and their formulation facilities are often
located on the same premises or in close proximity to their corporate offices.
Individual Formulation Plant Characteristics: Individual formulation plants
are designed to meet the specific needs of the company and location. There
is quite a range in the type of products formulated, the rates of production,
and the age of the facilities in which they are manufactured.
The types of pesticides produced can be classified in two ways: by the
chemical class of pesticide processed, or by the form of the product. Both
measures are important when considering wastewater characteristics and
volumes.
A recent study categorized 550 pesticidal chemicals into seven major cate-
gories, which were further divided into 42 subcategories.—' (See Appendix
C.) For the purpose of characterizing formulation plants, however, pesti-
cidal chemicals can be classed as: inorganics, organophosphates, nitrogen-
based, chlorinated hydrocarbons, and all others. Figure 9a illustrates the
distribution of product mixtures found for 96 large formulation plants.
Pesticide formulations can also be classified as liquids, granules, dusts
and powders, and all other forms. Figure 9b shows the distribution of 92
major formulation plants according to this classification.
The scale on which pesticides' are produced covers quite a range. Undoubted-
ly, many of the small firms having only one product registration produce
only a few hundred pounds of formulated pesticides each year. At least one
plant has been identified that operates in the range of 100,000,000 Ib of
formulated product per year. The bulk of pesticide formulations, however,
is apparently produced by independent formulators operating in the 20,000,000
to 40,000,000 Ib per year range.
24
-------
Ul
Figure 6 - Large Formulation Plant Locations
-------
t >
a
I
Figure 7 - Geographical Distribution of Companies
Holding Federal Registrations
-------
!
1
Figure 8 - Distribution of Federal Registrations
by Company Location
-------
I/I
c
c
0)
u
40
30
20
10
n
—
_
—
—
—
28.1 ,
•x-x-x-x-
iilii
MM
x:x:::::::x
29.2
:::::x:::::::::
:':XJ>>X;X
:j:|>x':x|x
oo o
£.£. .7
X;X:X; <<
:•:•:•:•:•: :•:•:•
:ji;:|xx x-:;
12.5
iifij 7.3
1 2 3
Number of Classes Formulated
Classes: Organophosphate, inorganic, chlorinated
hydrocarbon, nitrogen based,and all
others
a) Distribution by Chemical Class of Pesticde Formulated
80 r-
61.9
•§ 60
o
0.
14-
° 40
c
0)
t£ 20
n
—
—
•:•:•:•:•:•:•:•:•:
23.9
14.0
$S$?Ss |
1234
Number of Types Formulated
Types: Liquids .powders and dusts, granules,and
all others (strips, baits, etc)
b) Distribution by Type of Formulation
Figure 9 - Product Distribution for Large Formulation Plants
28
-------
The ages of formulation plants identified during this study ranged from 1
to 53 years. Distribution according to age for 102 large formulation plants
is shown in Figure 10.
29
-------
24 r-
20
16
c
o
o 12
I*
4)
i
•:
D
z
8
1-5 6-10 11-15 16-20 21-25 26-3031-35 36-40 41-4546-50 51-55
Age in Years
Figure 10 - Distribution of Plants by Age
30
-------
SECTION V
WASTEWATER CHARACTERIZATION
The quantity and quality of wastewater generated by a formulation plant are
determined by factors such as the type of formulations produced, the active
ingredients used, the age and size of the facility, the plant's production
schedule, and the company's operating philosophies and procedures. The
ranges over which these factors can vary have already been discussed in
Section IV. In this section, their effects on wastewater generation, as
well as characteristics of the wastewater produced, are reviewed. The uses
of water in a formulation plant, operating methods that control the volume
of wastewater produced, and characteristics of process wastewater are dis-
cussed in the following subsections.
Water Uses and Wastewater Sources
Water is used for a number of purposes in a pesticide formulation plant.
Some of these uses result in the generation of wastewater streams that con-
tain various concentrations of pollutants. Other uses either generate no
wastewater or yield an effluent that presents no significant pollution
problem.
CoolinR Water: Cooling water is required by several processes found in
pesticide formulation plants. One of the most common uses is to cool air
compressors used in conjunction with air mills that produce wettable pow-
ders. Cooling water is also required by many of the roller mills used for
dust production.
Effluent from the cooling water loop is generally free from significant
contamination, and, if kept separated from contaminated streams, can be
discharged from the plant site via a conventional drainage system or into
the sanitary waste.
Boiler Water: Steam is frequently used for space heating as well as in the
actual formulation process. Slowdown water from the boiler system, as well
as steam condensate that is not recycled, is generally free of toxicant
contamination. These streams, if kept isolated, can also be disposed of
with the other noncontaminated streams.
Steam is sometimes used to clean out formulation equipment. Condensate
from such operations is not returned to the heating cycle, but is treated
with equipment washdown water.
31
-------
Formula Water; Some liquid formulations contain water as their base.
Primarily herbicides are formulated in this manner. The formula water
used in these formulations accounts for a major part of the water consumed
by many formulation plants.
Sanitary Wastes: Sanitary wastes are generated at virtually all formula-
tion plants. This category includes not only conventional sewage, but also
the wastewater generated from shower facilities and washwater from work
clothes processed on the plant site. Normally, this waste stream is treated
as conventional sanitary waste, and discharged into municipal sewage treat-
ment or septic tank systems.
At least one pesticide manufacturing-formulating plant, however, has re-
moved lavatory effluent from the sanitary waste stream in order to ensure
"zero discharge" of active ingredient.l^./
Building Washdown: For housekeeping purposes, most femulators clean out
the buildings housing formulation units on a routine basis, frequently once
each year. Prior to washdown, as much dust, dirt, etc., as possible is
swept and vacuumed up. The wastewater from the building washdown is nor-
mally contained within the building, and is disposed of in whatever manner
is used for other contaminated wastewater.
Air Pollution Control Devices: Water scrubbing devices are often used to
control emissions to the air. Most of these devices generate a wastewater
stream that is potentially contaminated with pesticidal materials. One
type of widely used air scrubber is the roto-clone separator. In this
device, air is cleaned by the combined action of centrifugal force and
mixing. Although the quantity of water in the system is high—about 20 gal.
per 1,000 CFM—water consumption is kept low by a recycle-sludge removal
system.—' Effluent from air pollution control equipment should be disposed
of with other contaminated wastewater.
Drum Washing: A few formulation plants process used pesticide drums so
that they can be sold to a drum reconditioner or reused by the formulator
for appropriate products, or simply to decontaminate the drums before they
are disposed of. Drum washing procedures range from a single rinse with
a small volume of caustic solution or water, to complete decontamination
and reconditioning processes. Wastewaters from drum washing operations are
contained within the processing area and treated with other processing
wastewater.
Control Laboratories: Most of the larger formulation plants have some type
of control lab on the plant site. The control analyses performed range from
determination of specific gravity only, to complete spectrophotometric
analyses. Wastewater from the control laboratories, therefore, can range
32
-------
from an insignificantly small, slightly contaminated stream to a rather con-
centrated source of contamination. In many cases, this stream can be dis-
charged into the sanitary waste stream. Larger, more highly contaminated
streams must be treated along with other contaminated wastewater.
Formulation Equipment Cleanup: The major source of contaminated wastewater
from pesticide formulation plants is equipment cleanup. Formulation lines,
including filling equipment, must be cleaned out periodically to prevent
cross contamination of one product with another. Infrequently, equipment
must also be cleaned out so that needed maintenance may be performed.
Liquid formulation lines are cleaned out most frequently, and generally
require the most water. All parts of the system that potentially contain
pesticidal ingredients must be cleaned (see Figure 1, page 16). More than
one rinsing of process vessels and lines is required to get the system clean.
As a general rule, the smaller the capacity of the line, the more critical
cleanup becomes in order to avoid cross contamination. Thus, larger volumes
of washwater are required, relative to production quantity, for smaller units,
Granule as well as dust and powder lines also require cleanup. Liquid
washouts are generally required, however, only in that portion of the units
where liquids are normally present, i.e., the active ingredient pumping
system, scales, and lines. The remainder of these production units can
normally be cleaned out by "dry washing" with an inert material, such as
clay.
Spills: Spills of technical material or material in process are normally
absorbed on sand or clay, and are disposed of with other potentially toxic
solid wastes. If the spill area is washed down, the resultant wastewater
should be disposed of with the other contaminated wastewaters.
Runoff: Natural runoff, if not properly handled, can become a major factor
in the operation of wastewater systems simply because of hydraulic loading.
Isolation of runoff from any contaminated process areas or wastewaters,
however, eliminates its potential for becoming significantly contaminated
with pesticides. Uncontaminated runoff can be allowed to drain naturally
from the plant site.
In some plants, formulation units, filling lines, and storage areas are
located in the open. The runoff from these potentially contaminated areas,
as a rule, cannot be assumed to be free of pollutants and should not be
allowed to discharge directly from the plant site.
Catastrophic Events: In addition to routine generation of wastewater, there
exists the possibility of polluted water resulting from a catastrophic event,
including fires, floods, and major spills. Diking of the formulation plant
33
-------
is the most common method for minimizing pollution from such a source.
Segregation of materials in storage as well as preventive cooperation with
local fire, police, and health departments also help to isolate the polluted
area and prevent unnecessary dispersion.
Operating Methods Affecting Wastewater Volume: There are a number of tech-
niques, if made a part of the routine operation of a formulation plant,
that can help minimize the volume of process wastewater, i.e., water poten-
tially contaminated with significant quantities of pollutants. In most
cases the degree to which these are applied are more a factor in determining
the wastewater volume than scale of production. The following discussion
lists minimization techniques that are applicable to most plants.
Segregation; Many effluent streams have little potential for containing
pollutants, including cooling water, boiler water, and most sanitary wastes.
These "clean" streams should be kept isolated from contaminated areas and
streams so that they can be discharged directly from the plant site.
Scheduling: Production runs should be scheduled wherever possible so that
the number of equipment cleanups is minimized. Production of liquid formu-
lations containing active ingredients A, B, and C, for example, would be
sequenced so that those containing only A would be produced first; then
those containing A and B; and finally those containing A, B, and C. Such
a sequence would require no cleanups between runs to avoid contamination.
Use of this technique, however, is limited because of the frequency with
which formulation plant production schedules are revised.
Water Conservation: When water washing is required, a minimum volume of
water must be used. Although this seems a trite statement, it is one of
the best ways to reduce the volume of wastewater. Water conservation
techniques include the use of specified volumes of water, rinsing out rather
than filling and flushing, and use of timers on water lines.
Solvent Washouts: Organic solvents can often be used rather than water to
clean up a formulation unit. The solvent used for cleanup can be saved,
and stored in drums until the next time the previously formulated ingredient
is produced. The retained solvent can then be used as part of the produc-
tion batch. This technique not only eliminates the generation of washwater,
but it also can save small quantities of product that otherwise would be
lost. Application of this method is limited, however, by a lack of storage
space as well as the production of "one time only" formulations.
Sumps: Sumps can be installed in new plants to collect and contain contami-
nated wastewater or spills. When used in conjunction with curbing around
formulation units, sumps minimize area cleanup and washwater requirements.
34
-------
Dry Cleaning: The major portion of granule, dust, and powder formulation
units can be sufficiently cleaned out by processing an appropriate inert
carrier through the system. The inert carrier can be retained for use in
the next similar batch, or can be discharged with other potentially toxic
solid wastes. In either case, the dry wash technique can reduce the water
required to clean out solid formulation units.
Product Separation: Companies having more than one formulation plant or
those producing a limited number of active ingredients can reduce their
wastewater volumes by two techniques.
The first involves the consolidation of product formulation. A number of
firms have found that they can competitively produce all of a given product
at one or two locations, thereby simplifying their overall operations, and
reducing the number of cleanouts required. This approach, however, is not
only limited to the few companies who have multiple site operations, but
also has the economic disadvantage of increased transportation costs.
Some plants have been able to dedicate certain formulation lines to the
production of specific active ingredients or formulations, and have thereby
reduced clean-out requirements. Application of this technique, however,
is also rather limited.
Wastewater Characteristics
Comprehensive data on the volume and quality of wastewater from pesticide
formulation plants are virtually nonexistent. This is due in part to the
fact that many of the formulation facilities operated by active-ingredient
manufacturers are actually part of the pesticide manufacturing complex,
and effluents from the formulation section of these plants have not been
isolated and characterized. Another factor is that effluent analysis has
not been heretofore required for many other formulation plants. A large
part of this industry did not come under the provisions of the permit pro-
gram implemented under the River and Harbor Act of 1899 (33 USC 407), and
most formulation plants have simply never analyzed their wastewater.
Some generalizations on formulation plant wastewater can be made based on
the data obtained from visits to key formulation plants, as well as limited
data from regulatory agencies. The absence of complete sets of data
(wastewater quality and quantity, as well as production quantities and
characteristics), however, precludes the extrapolation of these generaliza-
tions into quantitative values, such as pounds of pollutant per unit of
product.
35
-------
Process Wastewater Quantity; The quantity of process wastewater, i.e.,
water containing pesticidal materials as a result of the plant's operation,
is influenced by many factors, as outlined in the preceding sections.
From the available data, relative volumes of wastewater produced cannot be
directly correlated with any one of these factors. Higher quantities,
however, are more frequently associated with plants that do not segregate
runoff from process wastewater.
There is apparently a wide range in the volume of wastewater generated.
The key formulation plants studied (see Appendix A) generated from less
than 1 to more than 25 gal. of wastewater per ton of formulated product.
Volumes of wastewater near the top of this range were generated by plants
that isolate the runoff as well as those who did not.
Process Wastewater Quality: A limited amount of quantitative data on for-
mulation plant effluents was obtained during the course of this study.
Data were obtained, for example, on a synthesized sample that had been
prepared in order to evaluate its waste treatment requirements. Analysis
of the samples showed:
pH 5.7
Total Organic Carbon 420 mg/liter
Suspended Solids 70 mg/liter
Conductance 290 umho/cm
Toxicant Concentration Not determined
One analysis made of the effluent from a formulation plant showed:
COD 483 mg/liter
Suspended Solids 661 mg/liter
Total Dissolved Solids 631 mg/liter
Arsenic 37 mg/liter
Flow Rate ~ 26 gpm
Toxicant Concentration Not determined
36
-------
Analyses of effluent from another formulation plant, performed by a regional
EPA office, showed:
PH
Total Organic Carbon
Suspended Solids
Total Dissolved Solids
Flow Rate
2,4-D
2,4,5-T
Malathion
Methoxychlor
Not determined
Not determined
Not determined
Not determined
Not determined
28.5 to 1,190 mg/liter
3.91 to 162 mg/liter
2.06 mg/liter
0.13 mg/liter
Two indexes against which formulation effluent can be measured are shown
in Tables 4 and 5, The first of these is a classification system for
ranking industrial wastewater. On this scale of low, average, and high,
process wastewater for this industry probably would be classified as
follows:
BODt
COD
Suspended Solids
Total Dissolved Solids
Average to high
Average to high
Low
Low
pH Low to average
37
-------
TABLE 4
CLASSIFICATION OF INDUSTRIAL WASTEWATER CHARACTERISTICS—'
26/
Parameter
BODc, mg/liter
COD, mg/liter
Suspended Solids, mg/liter
Total Dissolved Solids,
mg/liter
Ammonia, mg/liter
Total Phosphorus, mg/liter
Temperature, °c
PH
Low
<200
<300
<200
<500
< 15
< 8
< 15
< 6
Classification
Average
200-300
300-400
200-300
500-600
15-25
8-12
15-25
6-8
High
>300
>450
>300
>600
> 25
> 12
> 25
> 8
38
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TABLE 5
GUIDELINES FOR PESTICIDE CONTENT OF WATER
Proposed
New Drinking Criteria for
Water Guideline!!/ Water Quality!®./
Pesticides
Aldrin
Chlordane
DDT
Dieldrin
Endrin
Heptachlor
Heptachlor Epoxide
Lindane
Methoxychlor
Toxaphene
2,4-D
2,4,5-TP (Silvex)
2,4,5-T
Organophosphate and
Carbamate Insecti-
cides
(rag/ liter)
0.001
0.003
0.05
0.001
0.0005
0.0001
0.0001
0.005
1.0
0.005
0.02
0.03
0.002
O.ll/
(ue/liter)
0.01
0.04
0.002
0.005
0.002
0.01
-
0.02
0.005
0.01
-
-
-
M
a/ Expressed in terms of parathion-equivalent
cholinesterase inhibition.
b/ Effluent standard for aldrin and dieldrin combined.
Proposed Toxic
Pollutant Effluent
Standards!?/
(UK/liter)
0.5k/
0.2
b/
0.2
1.0
39
-------
Ammonia concentration, phosphorus concentration and temperature can be
expected to range from high to low, depending on the individual plant.
As a baseline for comparison, proposed guidelines for pesticides in various
waters are shown in Table 5. Pesticide concentration in formulation waste-
water reportedly ranges from < 10 to over 1,000 ppm. Most frequently, how-
ever, toxicant concentrations range from 10 to 200 ppm.
The data above are not indicative of unusual operating conditions, e.g.,
spills. Wastewater generated during periods of unusual operation can be
expected to rank "high" on all pollutant parameters.
40
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SECTION VI
CURRENT WASTEWATER TREATMENT PRACTICES
The treatment techniques currently being used for formulation plant waste-
water can be. grouped into several general categories: evaporation, sewer
system, landfill, contract disposal, activated carbon adsorption, incinera-
tion, and miscellaneous pretreatment processes. The following discussions
of these techniques are arranged according to their decreasing frequency of
use by large formulation plants (see Figure 6, page 25).
Evaporation
Evaporation is the wastewater treatment technique most frequently employed.
Evaporative systems range from those that just concentrate wastes by partial
wastewater evaporation, to processes that evaporate all wastewater produced.
Evaporative systems can be used in most parts of the country (see Figure 11),
depending primarily on the characteristics of the individual plant's opera-
tion. Systems range in size from 2,000 to over 1,000,000 gal. of wastewater
evaporation per year.
Designs of the systems vary with the plant (see Case Studies Nos. 1, 2, and
8 in Appendix A). General considerations in all designs, however, revolve
around the need to maintain an adequate evaporation rate.
A pretreatment step is sometimes required to break emulsions. This is usually
done by batch-wise addition of a deemulsifying agent followed by gravity
separation of the organic layer. This layer is usually disposed of by in-
cineration, or in the case of spray oil formulation, by use as road oil.
After pretreatment, the wastewater is pumped into an evaporation pond where
it is allowed to evaporate. These range from shallow, concrete pads to
large (1 acre or more) man-made earthen ponds. When earthen ponds are used,
they are preferably sealed with bentonite, plastic, or other lining materials
to prevent percolation into the soil.
The natural rate of evaporation is normally not adequate to accommodate all
process wastewater in a pond of reasonable size. In addition, as can be
seen from Figures 12 and 13, few parts of the country have net annual evapo-
ration of rain water. For these reasons, almost all wastewater evaporation
systems employ additional techniques to obtain adequate evaporation.
Roofs; Many of the small evaporation ponds (up to 50 ft x 50 ft) use roofs
to keep out rain water. Permanent roofs, even those made of "transparent"
plastic materials, however, reduce the rate of natural evaporation.
41
-------
I •»
Figure 11 - Formulation Plants Using Evaporative Treatment Systems
-------
:
'--
Figure 12 - Mean Annual Inches of Lake Evaporation^/
-------
31/
Figure 13 - Mean Annual Inches of Precipitation—
-------
Awning-type coverings, that can be moved when not needed, overcome this
deficiency, but obviously add to installation and operation costs.
Aeration Systems; To aid natural evaporation, aeration systems are fre-
quently used. These are normally simple, low cost pumping systems used to
spray the wastewater into the air. A number of variations are possible,
including the use of burlap strips, waterfalls, etc., to increase the ef-
fective evaporative area. Aeration has the added advantage of oxygenating
the water and thereby accelerating the decomposition of many pesticide
chemicals.
Supplemental Heat: Supplemental heating also is used to aid the evapora-
tion rate. Most frequently, this is done by the addition of conventional
electrical or gas powered immersion heat exchangers to the evaporation pond.
Supplemental heat is normally required for only a few months each produc-
tion season.
Limitations: One of the major limitations of this system is the uncertainty
of air pollution problems that may be created. This problem is discussed
in more detail in Section VIII (page 55) of this report.
Sewer Systems
Many smaller and a few large formulation plants discharge into local munici-
pal or industrial sewer systems. Pretreatment techniques used by the for-
mulation plant in conjunction with these systems are minimal (see Miscella-
neous Pretreatment Processes, page 47). The pH of the effluent is normally
adjusted to neutrality or to that of the local groundwater. Effluents from
a few plants are filtered before discharge. Limitations are established by
local authorities on the concentration as well as the daily quantity of
toxicants that can be discharged. Some municipal sewer systems, however,
have not established criteria on the toxicant (pesticide) content of waste-
water that can be discharged to their treatment systems.
The limitations of many existing treatment plants, with regard to their
ability to remove pesticides from water, are well documented.32"357 por
these reasons, it is critically important that capabilities of the individ-
ual treatment system be determined before discharge of formulation waste-
waters into the system is considered.
Landfills
Small formulation plants as well as larger plants producing small volumes
of wastewater (< 10,000 gal/year) are frequently able to dispose of their
wastewater in landfills. The landfill facilities in use include cut-and-
fill operations located on the plant site, as well as a wide range of
municipally and industrially operated sites.
45
-------
The actual disposal procedures used at the landfill also are quite varied.
Most frequently, the small volumes of wastewater are sealed in used 55-gal.
drums. The wastewater drums are then treated like any other item of solid
waste. Another practice in use, however, is to convey the wastewater to the
landfill site in a bulk container, and spray it on the fill area.
Sites in which formulation wastewaters are disposed of normally have not estal
lished criteria on the quality of the wastewater allowed and do not main-
tain records of the quantity or location of wastewater in the fill.
Almost all of the landfill sites apparently operate under some type of per-
mit, either local or state. Very few, if any, of these sites, however,
qualify as "specially designed landfill" operations that have been defined
for use in pesticide waste disposal.—' (See "Special Landfill" in Appen-
dix B, page 111.)
Contract Disposal
The next most frequently practiced method for disposing of process waste-
water is the use of a contract disposal service. The availability of this
service in the immediate area, as well as the cost involved, are major fac-
tors in its selection. Care must be taken, however, to ensure that the
wastewater is properly processed by the contractor. (See "Contract Services'
in Appendix B, page 118.)
Activated Carbon Adsorption
The effectiveness of activated carbon in removing low concentrations of
many pesticides in water has been well documented.33,35,37/ A limited
number of formulation plants are attempting to apply activated carbon ad-
sorption technology to treatment of their effluent streams. (See Case
Studies Nos. 7, 9, and 10 in Appendix A.)
Most of the plants using carbon, however, apparently are doing so only on
an experimental basis. None of the plants identified during this study are
considered by the operating firms to be in full-scale operation; rather,
they are in various stages of development.
Incineration
Incineration in appropriate facilities is the method of choice for disposal
of all pesticides except for organometallics and inorganic compounds.^/
Adequate facilities, however, are generally not available to the independent
and contract pesticide formulators. In fact, the only formulation plants
identified as using incineration to dispose of their process wastewaters
were those in chemical manufacturing complexes. Incinerators are used,
however, by some contract waste disposal services.
46
-------
Miscellaneous Pretreatment Processes
A small number of plants are using an assortment of miscellaneous unit oper-
ations to treat their wastewater. None of these, however, can be considered
a complete treatment process; rather, they are pretreatment processes used
to treat wastewater before it is discharged.
Conventional pretreatment processes as well as the protective functions that
they serve are shown in Table 6.Z§/ Only four of these are practiced to any
significant degree by the pesticide formulation industry.
Neutralization: Many plants treat their wastewater with caustic before it
is discharged. This is done primarily to produce a neutral effluent, or
because it is thought that this will help detoxify the pesticidal chemicals.
The frequently used generalization that alkaline conditions reduce the
toxicity of pesticidal chemicals by hydrolysis, however, is not universally
true.—' The formulator should determine the desirability of high alkalin-
ity based on the active ingredients being formulated before adopting this
practice.
Chemical Precipitation: Many inorganics can be removed from wastewater by
precipitation. One plant that formulates primarily mercurial pesticides,
for example, uses sodium hydroxide to precipitate the mercury, which is then
filtered and recovered for reprocessing.l^/ Use of chemical precipitation
processes, however, is not commonly practiced.
Solids Separation: Some plants filter their wastewater before discharge.
When used in conjunction with precipitation or flocculation, this process
apparently can effect some reduction of pesticide content of the wastewater.
Filtration alone, however, is not considered to be a complete treatment
process.
Equalization: Equalization, i.e., elimination of wide variations in waste-
water quantity and quality before discharge, is practiced by some plants.
As this is essentially a retention and dilution system, it does not effect
a significant reduction in the total quantity of toxic pollutants that is
eventually discharged. It can, however, prevent short discharges of highly
toxic wastes which might cause a fish-kill or environmental damage.
47
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TABLE 6
PRETREATMENT PROCESSES AND THEIR
Pretreatment
Process
Screening
Grit Removal
Neutralization
Oil Separation
Equalization
Cooling
Solids Separation
Chemical Precipitation
Foam Control
Spill Protection
PROTECTIVE
Collection
System
X
X
X
X
X
X
X
FUNCTIONS2^/
Protective
Pumping
Equipment
X
X
X
X
X
X
X
Function
Treatment Plant
and Operating Personnel
X
X
X
X
X
X
X
X
48
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SECTION VII
BEST TREATMENT TECHNOLOGIES
The establishment of "best practicable" and "best available" technologies
for the treatment of various industrial wastewaters is required by the
Federal Water Pollution Control Act of 1972.fL/
By 1 July 1977, industries are expected to meet effluent limits that reflect
the use of best practicable control technology. This technology is to be
based on end-of-the-line treatment techniques rather than on modification
or cleaning up of the production process itself. Parameters to be considered
in the definition of what is best practicable are the age of the facilities
involved, the engineering effort required to apply various types of control
technology, and the cost of effecting reductions in pollutant discharge.
By 1 July 1983, industries are to meet effluent limits that reflect the use
of best available control technology. As a national goal, by 1985, indus-
tries must completely eliminate the discharge of pollutants wherever this
is technologically and economically achievable.2^3.7
Best available technology includes in-process control technology as well
as processes for treating wastewater. These guidelines will be applied to
all plants within an industry category.
As a part of this study, we have attempted to define best treatment tech-
nologies for pesticide formulation plants. As has been done throughout
this study, formulation plants that are an integral part of a chemical
manufacturing facility have not been included.
Cost estimates also have been made in order to establish the order of
magnitude of the economic impact that would result from application of
these systems to the formulation industry. Conservative (optimistic), yet
realistic cost data as well as readily available, off-the-shelf items of
equipment have been used in developing these estimates so that costs for
the minimum adequate system could be evaluated. These same procedures,
built to the more exacting specifications used-by many of the larger pro-
ducer formulators, could cost 10 times our conservative estimates.
Best Practicable Technology
The best practicable wastewater treatment technology, based on the treat-
ment practices in use within the industry, appears to be evaporative
systems with no discharge of water for most plants in the industry. For
plants not able to effect complete evaporation of their process wastewater,
partial evaporation used in conjunction with disposal in an approved
49
-------
landfill and in accordance with EPA guidelines appears to be the best
alternative. (See Appendix B, "Burial," page 110.)
The operational and design characteristics of evaporative systems have
been discussed in Section VI of this report (see "Evaporation," page 41).
Obviously, each system would have to be tailored to the needs of the
individual plant site.
A preliminary design of an evaporative system is shown in Figure 14. A
surge tank would be required to accumulate wastewater for batch-wise de-
emulsification, if required. Wastewater would then be pumped into an
evaporation pond that was fitted with such ancillary equipment as required
to obtain the needed rate of evaporation.
Preliminary process designs show that a system capable of treating the ef-
fluent from a large formulation plant (one producing 40,000,000 Ib/year of
formulated product and generating 500,000 gal. of process wastewater) can
probably be constructed for less than $10,000 (exclusive of land value)
and operated at a cost less than lc/gal. (See Appendix D, Cost Estimate
No. 1, and Appendix A, Case Studies Nos. 1, 2, and 8.)
An integral part of this system is the minimization of process wastewater.
Operating methods that reduce the volume of wastewater must be used to the
fullest extent possible. (See Operating Methods Affecting Wastewater
Volume, page 34.)
The major uncertainty in the use of evaporative systems is the air pollu-
tion that may be created. The extent or seriousness of the air pollution
caused by the evaporation of pesticides from the wastewater has not been
established. Recent study has shown, however, that the transfer of con-
taminants (e.g., pesticides) from water to air by evaporation may be
occurring much faster than has been generally realized.££/ When aqueous
solutions of DDT were evaporated, for example, it was shown that 977. of
the DDT initially present (dissolved) had evaporated when only 5.2% of the
water had been evaporated. In addition, the losses of pesticides by other
water-to-air transfer mechanisms are quite possible.
Best Available Technology
The best wastewater treatment technology available appears to be a process
including pretreatment (neutralization, precipitation, and/or deemulsifica-
tion), filtration, and adsorption on activated carbon and/or resin.
Processes that included these basic concepts have been applied to a number
of industrial effluents.z2lfL?./ Adsorption techniques also have been found
to be highly effective in removing toxic chemicals, e.g., pesticides, from
various wastewaters.^3*^/
50
-------
Surge Tank
Roof
A f S Evaporation Pond
System
Figure 14 - Evaporative Wastewater Treatment
-------
One of the large pesticide formulation plants in the United States is cur-
rently experimenting with a pilot plant using essentially this process.
(See Appendix A, Case Study No. 7.)
The plant has been able to routinely produce an effluent containing less
than 0.1 ppm total toxicants (pesticides).
Figure 15 shows the potential flow diagram for such a system based on the
results of one pilot plant's operation and standard carbon adsorption de-
sign parameters ..^L' A preliminary cost estimate has been made in order
to estimate the capital and operating cost of such a system. (See Appendix
D, Cost Estimate No. 2.) The preliminary data indicate that process waste-
water from a plant producing 40,000,000 Ib of formulated product/year can
probably be treated for a cost of about 2$/gal. Capital costs for the
minimal system are estimated to be in the order of $20,000 (exclusive of
land value).
52
-------
Surge Tank
Pretreatment
Tank
Vacuum
Filter
10
Adsorption
Column
Spent
Carbon
Effluent
Figure 15 - Pretreatment-Filtration-Adsorption Systems
-------
SECTION VIII
RESEARCH AND DEVELOPMENT NEEDS
A significant amount of research and development work is needed to charac-
terize formulation wastewater from pesticide formulation facilities, and
to evaluate methods for its treatment. For example, not one complete set
of data (quantitative and qualitative information on both production and
wastewater) was found during the course of this study.
There are at least four problem areas which will have to be evaluated before
"closed loop" wastewater systems or the complete elimination of pollutant
discharge can be effected. These areas of research are discussed in the
following subsections in the sequence in which they should be undertaken.
Wastewater Characterization
The first area requiring additional work is the characterization of waste-
water produced from formulation plants. This would include both quanita-
tive and qualitative determinations. The sources and the properties of
contaminated wastewater must be determined. Wastewater must be character-
ized not only in terms of conventional quality parameters (temperature,
pH, BOD, COD, total organic carbon, suspended solids, etc.), but also in
terms of the concentration of toxicant chemicals present.
The formulation industry is a seasonal operation, with a wide range of
types and sizes of facilities. Representative formulation plants, there-
fore, must be monitored for a complete production season in order to
develop accurate wastewater data.
Evaporative Wastewater Treatment Systems
Evaporative systems are widely used to process formulation wastewater, and
have been identified in this report as the best practicable control tech-
nology currently available.
One of the uncertainties involved in the application of evaporative processes
to wastewaters containing pesticide, however, is the potential air pollution
problem. The evaporative loss of pesticides when spread over large crop
areas has been an acknowledged problem for a number of years and has been
the subject of a number of studies.—' A recent research study, however,
as discussed in the preceding section on Best Practicable Technology (page
49), has shown that the transfer of contaminants., e.g., pesticides, from
water to air environments may occur much faster than has been generally
realized.
55
-------
A research study is needed to quantify the air pollution resulting from
the use of evaporative systems to process pesticide formulation wastewater.
This study would also require monitoring of representative sites for a
complete production cycle.
Pretreatment-Filtration-Adsorption System
The system of pretreatment (neutralization, precipitation, and/or deemulsi-
fication), filtration and adsorption (activated carbon and/or resin) of
formulation wastewater has not been completely demonstrated. Operating ant
design criteria as well as the system's economic viability must be deter-
mined before this system can be defined as the best available technology
for treatment of formulation wastewater.
In order to make an evaluation, the operation of a representative pilot
plant system would have to be monitored for at least one complete produc-
tion season.
Detoxification Processes
The ultimate process for treatment of toxicant-containing wastewater is a
detoxification system. The waste treatment systems currently being used
to process wastewater from active ingredient manufacturing sites are well
documented.z2/ Many of these are chemical and biological detoxification
processes that have potential application to formulation plant wastewater.
A study of the applicability of the treatment technologies should be con-
ducted concurrently with the three research studies outlined above.
56
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SECTION IX
REFERENCES
1. National Agricultural Chemicals Association. Manual on Waste Disposal.
Washington, B.C. June 1965.
2. "Federal Water Pollution Control Act Amendments of 1972," Public Law
92-500, 92nd Congress, S. 2770 18 October 1972.
3. Office of Public Affairs. "Action for Environmental Quality," U.S.
Environmental Protection Agency. U.S. Government Printing Office, Stock
No. 5500-00087, Washington, D.C. March 1973.
4. von Rumker, R., H. R. Guest, and W. M. Upholt. "The Search for Safer,
More Selective and Less Persistent Pesticides." BioScience, 20(18):
1004-1007. 1970.
5. Green, M. B. "Are Herbicides Too Expensive?" Weeds Today, 4(3):14-16.
Summer 1973.
6. Gould, R. F. (Editor). Pesticidal Formulations Research, Advances in
Chemistry Series 86. American Chemical Society, Washington, D. C.
1967.
7. Entley, W. J., D. C. Blue, and H. A. Stansbury. "Techniques Used in
Formulating 'Sevin'." Farm Chemicals, 128(6):52-60. June 1965
8. Coombs, G. "Pesticide Formulation." Agricultural Chemicals, 15(6):
47-103. 1960.
9. Van Valkenburg, J. W. (Editor). Pesticide Formulations. Marcel Dekker,
Inc., New York, New York. 1973.
10. Farm Chemicals Handbook 1973. Mesiter Publishing Company, Willoughby,
Ohio. 1973
11. "Formulating by Computer." Farm Chemicals. 130(9);90-92. 1967.
57
-------
12. Mrak, E. M. (Chairman). Report to the Secretary's Commission on
Pesticides and Their Relationship to Environmental Health. U.S. Government
Printing Office, Washington, D.C. December 1969.
13. Lawless, E. W., R. von Rumker, and T. L. Ferguson. The Pollution
Potential in Pesticide Manufacture. EPA Technical Studies Report
TS-00-72-04. U.S. Government Printing Office, Washington, D.C.
June 1972.
14. Pesticide Enforcement Division. "Listing of Federal Pesticide Registration."
Environmental Protection Agency, Washington, D.C. 31 March 1973.
15. Kirk-Othtner Encyclopedia of Chemical Technology. 2nd Edition, Vol.
II. Interscience Publishers, New York. 1966
16. Hersey, J. "Choosing a Solvent for Insecticide Formulations."
Farm Chemicals. 129(10):42-46. October 1966.
17. Winchester, J. M., and D. Yeo. "Future Developments in Pesticide
Chemicals and Formulations." Chemistry and Industry, (4):106-108.
27 January 1968.
18. Herzka, A. International Encyclopedia of Pressurized Packaging.
Pergamon Press, New York, New York. 1966.
19. Handbook of Aldrin, Dieldrin and Endrin Formulations. Shell Chemical
Corporation, New York, New York. June 1959.
20. Raymond Division. Raymond Mills for Insecticides. Bulletin No. 84.
Combustion Engineering, Inc. 1957.
21. Danielson, J. A. (Editor). Air Pollution Engineering Manual,
Publication No. 999-AP-40. U.S. Department of Health, Education
and Welfare, Cincinnati, Ohio. 1967.
22. Pazar, C. Air and Gas Cleanup Equipment. 1970. Noyes Data Corporation,
Park Ridge, New Jersey. 1970.
23. Plant Protection Division. "Delaware River Basin - Survey of
Pesticide Formulators and Manufacturers." Agricultural Research
Service, U.S. Department of Agriculture; with cooperation of Delaware,
New Jersey, and Pennsylvania State Departments of Agriculture.
January 1970.
58
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24. Plant Protection Division. "Results of a Survey of Formulators,
Distributors, and Manufacturers of Pesticides in the Lake Michigan
Watershed." Agricultural Research Service, U.S. Department of
Agriculture; in cooperation with Michigan, Wisconsin, Illinois,
and Indiana State Departments of Agriculture. June 1969.
25. Sobelman, M. Personal communication. Montrose Chemical Corporation
of California. 5 October 1971.
26. Roy F. Weston, Inc. "Pretreatment Guidelines for the Discharge
of Industrial Wastes to Municipal Treatment Works." A draft pre-
pared under EPA Contract No. 68-0.1-0346. 17 November 1972.
27. "EPA Sets New Pesticide Limits in Drinking Water." Pesticide
Chemical News. l.(14):8. 7 March 1973.
28. Environmental Protection Agency. Proposed Criteria for Water
Quality. Volume I. Environmental Protection Agency, Washington,
D.C. October 1973.
29. Environmental Protection Agency. "Proposed Toxic Pollutant Effluent
Standards." Federal Register, 38(247):35388-35395. 27 December 1973.
30. Miller, D. W., J. J. Geraghty, and R. S. Collins. Water Atlas of
the United States. Water Information Center, Inc., Port Washington,
Long Island, New York. 1963.
31. U.S. Geological Survey. The National Atlas of the United States
of America. U.S. Department of Interior, Washington, D.C.
1970.
32. Cohen, J. M., L. J. Kamphake, A. E. Larake, C. Henderson, and R. L.
Woodward. "Effect of Fish Poisons on Water Supplied, Part I,
Removal of Toxic Materials." Journal of the American Water Works
Association. 52:1551. December 1960.
33. Edwards, C. A. Persistent Pesticides in the Environment. Chemical
Rubber Company, Cleveland, Ohio. 1970
34. Nicholson, H. P., A. R. Grzenda, and J. I. Teasley. "Water Pollution
by Insecticides." Journal of the American Water Works Association.
32(l):21-27. 1968.
59
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35. Robeck, G. G., K. A. Dostal, J. M. Cohen, and J. F. Kreissl.
"Effectiveness of Water Treatment Processes in Pesticides Removal."
Journal of the American Water Works Association. 57/2):181.
February 1965.
36. Environmental Protection Agency. "Pesticides and Pesticide Con-
tainers: Regulations for Acceptance and Recommended Procedures
for Disposal and Storage." Federal Register, 39(85):15236;15241.
1 May 1974.
37. Goodrich, P. R., and E. J. Monke. "Insecticide Adsorption on
Activated Carbon." Transactions of the American Society of
Agricultural Engineers. 13_(1): 56-57, 60. 1970.
38. Lawless, E. W., T. L. Ferguson, and A. F. Meiners. "Methods for
Disposal of Spilled and Unused Pesticides." A draft prepared
under EPA Contract No. 68-01-0098, Project 15090 HGR. July 1973.
39. Mackay, D., and A. W. Wolkoff. "Rate of Evaporation of Low-
Solubility Contaminants from Water Bodies to Atmosphere."
Environmental Science and Technology. 7/7):611-614. July 1973.
40. Abrams, M. "Removal of Organics from Water by Synthetic Resinous
Adsorbents." Chemical Engineering Progress. 65_(97) : 106-112. 1969.
41. Rizzo, J. L. "Adsorption/Filtration--A New Unit Process for the
Treatment of Industrial Wastewaters." A paper presented at the
63rd Annual American Institute of Chemical Engineers Meeting,
Chicago, Illinois. 29 November - 3 December 1970.
42. Paulson, E. G. "Adsorption as a Treatment of Refinery Effluent."
A paper presented at a session at the 35th Midyear Meeting of the
American Petroleum Institute's Division of Refinery, Rice Hotel,
Houston, Texas. 14 May 1970.
43. Kennedy, D. C. "Treatment of Effluent from Manufacture of Chlori-
nated Pesticides with a Synthetic, Polymer Adsorbent, Amberlite
XAD-4." Environmental Science and Technology. 7/2):138-141.
February 1973.
44. Rizzo, J. L. "Removal of Toxic Organic Chemicals by Filtration Ad-
sorption." A paper presented at the Third Symposium on Hazardous
Chemicals Handling and Disposal,Indianapolis, Indiana. 12 April 1972.
60
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45. Hartley, G. S. "Evaporation of Pesticides." Pesticidal Formulations
Research, Advances in Chemistry Series 86, Robert F. Gould (Editor).
American Chemical Society, Washington, D.C. 1969.
46. Atkins, P. R. The Pesticide Manufacturing Industry—Current Waste
Treatment and Disposal Practices. EPA Report No. 12020 FYE.
U.S. Government Printing Office, Washington, D.C. January 1972.
47. The Swindel-Dresser Company. Process Design Manual for Carbon
Adsorption. EPA Contract No. 14-12-928, Program No. 17020 GNR.
Environmental Protection Agency, Washington, D.C. October 1971.
61
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APPENDIX A
FORMULATION PLANT CASE STUDIES
Site visits were made to several pesticide formulation
plants throughout the United States. The following 10
case studies are presented as an appendix to this report
in order to document the quantity and quality of data
made available to the project team, as well as to illus-
trate, as specifically as possible, the operational char-
acteristics of pesticide formulation plants. The range
of detail in which these case studies are reported is
indicative of the extent to which corporate philosophies
differ over what data are confidential.
63
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CASE STUDIES
Case
No.
4
5
8
9
10
Location
Gulf Coast
Pacific West
Midwest
East North-Central
Midwest
Midwest
West North Central
Middle Atlantic
West South
South
Production
Rate
35 to 50
million Ib/yr
Large
40 million
Ib/year
Small
Medium
5 million
gal/yr
40 million
Ib/yr
Small
Large
3 million
gal/yr
Wastewater
Treatment
Technique
Total
evaporation
Total
evaporation
Contract
disposal
Landfill
Land
spreading
Contract
disposal
Pretreatment/
Filtration/
Adsorption
Total
evaporation
Adsorption
Adsorption
Page
No.
65
68
71
75
78
79
80
83
86
88
64
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CASE STUDY NO. 1
General Information
This formulation plant is one of about a dozen that are owned and operated
by a major manufacturer of pesticidal chemicals. The plant, the original
part of which is about. 20 years old, is located on a 15-acre site near the
Gulf Coast.
Production ranges from 35,000,000 to 50,000,000 Ib of formulated product
per year. A large portion of this production (/w 20,000,000 Ib) is sulfur
powder. Liquid and granular formulations containing ~ 3,500,000 Ib of
active ingredients are produced. The thiocarbamates make up ~ 75% of the
liquids. No parathion is formulated, and none of the formulations pro-
duced are water-based.
At one time, drums were cleaned at this plant site before being sold for
reconditioning and reuse. This operation, however, has been discontinued.
Quality control samples are analyzed on-site.
Process Information
The formulation equipment at this plant is typical of that used in the
industry. A Raymond mill is used to grind sulfur; this operation requires
a small volume of cooling water (~ 1 gpm). The grinding unit is located
within a building..
Liquids are formulated in four batch units ranging in sizes from 3,000 to
20,000 gal. Typically, batch sizes are in the 3,000 to 15,000 gal. range.
The four liquid units are located outside on concrete pads. Filling and
packaging equipment is moved from unit to unit as needed. This liquid
system is only 3 or 4 years old.
Organic solvents are used to wash out process equipment between production
runs. The solvent is redrummed, and stored until it can be used in the
next appropriate production run.
Wastewater Characteristics
The use of organic solvents for equipment washout virtually eliminates one
of the most common sources of wastewater. The small volume of process
wastewater (estimated to be 2,000 gal. per year) that is produced by wash-
downs, etc., flows into a retention pond whose level is maintained by
evaporation.
65
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Sanitary wastes go into the plant's own septic system.
Cooling water from the milling operation and from air compressors is used
to water grass and trees on the plant site. Excess cooling water from
these two sources is discharged from the plant site into a drainage ditch.
Runoff, as well as the process wastewater, is channeled into the evapora-
tive pond. Although analysis has not been made of the wastewater runoff
that drains into the pond, extensive data have been developed on the quality
of the water within the pond (Figure A-l).
Typical 1973 analysis of the water in the evaporative pond shows:
Dissolved oxygen 5 to 10 ppra
C02 5 ppm
pH 4 to 7
Phenol 0
Methyl orange 34.2
Total hardness 750 to 850
Toxicants < 1 ppm
Wastewater Treatment System
All process wastewater, as well as the runoff from the production area,
flows into a man-made evaporative pond. The pond is about 1 acre in size
and has a working capacity of about 1,000,000 gal. The pond is equipped
with an aeration system that pumps approximately 1,000 gpm of water some
25 ft into the air (four streams). This aerator consists of a salvaged
15-hp, three-stage water pump supported on a float which was fabricated by
plant personnel from used 55-gal. drums. The aerator is held in place in
the center of the evaporative pond by cables.
The only costs directly associated with the operation of this system are
the electrical and maintenance costs for the pump and the laboratory
support required to monitor the pond. No operating expenses are separately
charged against the system's operation although about 3 man-hours per week
of analytical time are required. Land value in this area is about $4,300
per acre.
Miscellaneous Information
This plant site has a state permit to operate an incinerator for the dis-
posal of solid wastes.
66
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30 r
25
20
a.
a.
c
o
u
c
o
U
15
10
,
\ / •. ..Chlorinated Hydrocarbons
^Herbicides
March
April
I May I June I July I August
September
Figure A-l - Holding Pond Analysis, 1971
-------
CASE STUDY NO. 2
General Information
This plant is one of the oldest and largest visited during this study.
It has been in operation in the Pacific West since the 1920fs, and annually
produces a large volume of solid formulations, as well as a significant
volume of liquids. About one-half of the solid formulations are sulfur
powder. The active ingredients which are formulated include major organo-
phosphates, chlorinated hydrocarbons, carbamates, as well as spray oil.
Organophosphate pesticides account for about 60 to 75% of the liquid for-
mulations, some of which are water-based.
The plant is located on about 12.5 acres within an industrial district,
and runs year round, normally on a one shift per day, 5 days per week basis.
During the peak season of February through May, however, two or three shifts
per day may be used. About 12 to 15 formulation unit turnarounds are re-
quired per month during this peak period.
There are five liquid formulation units, ranging in size from 100 gal. to
3,000 gal. capacity. If necessary, all units could be run concurrently,
although they normally are not.
In addition to pesticide formulation, this plant also washes drums for
reuse (for one inorganic pesticide and spray oil only). Washwater from
this operation goes into the process wastewater system.
The liquid formulation lines as well as the Raymond mill used for powders
are conventional batch units.
This plant maintains its own control lab on-site, and retains batch samples
for a 2-year period.
Wastewater Characteristics
Total water usage for the plant site was about 25,000 gal. per month in
1969. Although no data have been developed since that time, current water
usage is estimated to be lower because of operational changes that have been
instigated. Water is obtained from wells located on the plant site.
This plant is not connected to the local sewer system, and uses a septic
system to dispose of its sanitary wastes.
Primary sources of process wastewater are washdown of formulation equipment
and the washing of drums. Neither qualitative nor quantitative data, how-
ever, are available on these wastewaters. Estimates have been made that the
68
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drum washing operation and the actual pesticide formulation activities
each generate about 2,000 gpd of wastewater.
Wastewater Treatment System
Three separate systems are used for handling water: evaporation of rain-
water, evaporation of drum washings and runoff from the production area,
and evaporation of process wastewater.
Rainwater from most of the plant site (office buildings, parking area,
etc.) drains to a sump from which it is pumped to a low section of land
about 1.5 acres in area and allowed to evaporate.
Wastewater from the production lines, as well as the effluent from pesti-
cide drum washing, drains into sumps and is pumped into a 600,000-gal.,
open-top holding tank (see Figure A-2a). Caustic is used to adjust the pH
to approximately 7. From the holding tank, water flows into a 50-ft wide
x 50—ft long x 1—ft deep concrete evaporation pad. This pad is also
equipped with a 5-hp, 100-gpm pump which pumps the wastewater through an
aeration system consisting of a manifold of spray nozzles. A 10-ft burlap
fence has been installed on two sides of the pad to prevent vapor drift.
Water from spray oil drum washing is collected via a sump, and is pumped
into a 30,000-gal. tank (see Figure A-2b). A deemulsifier is added to the
washwater, and the oil phase is removed from the tank for use as road oil.
The water is then pumped from the tank into a 40-ft wide x 450-ft long x
2-ft deep fenced, bentonite-lined evaporation pond and is allowed to evapo-
rate. Rainwater that falls on the production area of the plant site flows
to a sump, and is pumped into this pond and allowed to evaporate.
No operating costs are split out for the wastewater treatment system.
About $1,400 worth of caustic and deemulsifier, however, are used each
year. Less than 10% of one worker's time is required to monitor the
system's operation.
Miscellaneous Information
Solid wastes such as sludge and empty containers are disposed of by a con-
tract disposal service in an approved cut-and-fill dump. Cost for this
service is about $1.00 per cubic yard, or about $300 to $500 per month.
An incinerator (two combustion chambers) is used to burn combustible wastes.
Land in this area costs about $6,000 per acre.
69
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Pesticide
Drum
Washing
1
Sump
1
Formulation
Units
1
Sumps
i
ffl '
A>-"A Pump
Holding
Tank
Pump
m
Evaporation Pad
Spray Oil
Drum
Washing
Sump
Pump
a) Process Wastewater Evaporation System
-**Truck
Holding
Tank
Portable
Pump
Production
Area Runoff
Sump
Evaporation Pond
b) Evaporation Pond System
Figure A-2 - Water Handling Systems
70
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CASE STUDY NO. 3
General Information
This formulation plant is located on about 10 acres of land in a large city
in the mid-United States, and is owned by one of the large manufacturers
of pesticidal chemicals. The plant came on stream in the early 1950*s.
Although production has expanded steadily since that time, no major changes
in the liquid filling line have been made in several years. The current
rate of growth in production volume is about 10% per year.
This plant produces a wide variety of insecticides and herbicides. Annual
production is in excess of 40,000,000 Ib of formulated products, which in-
cludes about 2,000,000 gal. of liquid formulations. Most of the liquids
(
-------
Sanitary wastes are currently processed through a sand filter, into a
holding pond, and eventually discharged into a small creek. Plans call
for connection with the local sewer system within the year.
Runoff is channeled into a gravity separator and then into a small holding
pond. This water is also discharged into the creek. The separator-holding
pond system provides a means for controlling large spills before they reach
a nearby creek.
Process wastewaters result primarily from the washdown of the liquid lines
between product runs and decontamination after parathion is formulated.
Due to limited storage space, organic solvent is not used for equipment
cleanup and retained for later use.
A complete analysis of the process wastewater has never been made. The
only parameter that is checked is pH, which remains essentially neutral.
It is estimated that this waste stream is about 307. organic (solvent, etc.)
and 70% water. About 12,000 gal. per month of process wastewater are
generated.
Recent efforts to minimize water usage have resulted in reducing the quan-
tity of wastewater. Volumes of wastewater from individual systems have
been specified, based on vessel sizes, length of lines, etc.
Spills of technical material normally do not reach the wastewater system.
Rather, spilled material is absorbed by a solid carrier, such as clay,
and is disposed of with the conventional solid wastes.
Wastewater Treatment System
The wastewater from the formulation process is kept isolated from sanitary
wastes and runoff by a special collection system (see Figure A-3). Wash-
water from the liquid formulation lines as well as the line used exclusively
for parathion formulation goes via floor drains to a collection sump located
in the formulation building. A similar system is used in the filling area.
From the two sumps, wastewater is pumped into one of two open-top holding
tanks whose combined capacity is 5,500 gal. Periodically, the tank is
emptied into tank trucks which transport the wastewater to the municipal
sewage treatment plant. Before the water is transferred to the tank truck,
however, the pH is checked and adjusted to that of local groundwater (8.0-
8.1). Potash is used to adjust the pH. Lime is not used at the plant and
there are no agitators in the storage tanks.
The major costs associated with this system are: a charge of $20 per 1,500-
gal. load of wastewater (total cost for transportation and dumping), and
$20 per load for the potash treatment. Current local cost to replace the
72
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Liquid
Formulation
Units
Pa rath ion
Formulation
Unit
Floor Drain
Holding
Tank
No. 1
Filling
Line
Floor Drain
Sump
Holding
Tank
No. 2
Gravity Flow
into Truck
Figure A-3 - Process Wastewater
73
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wastewater system would be about $7,000. No allocation of operating costs
are made against the waste disposal system.
Miscellaneous Information
This plant has had no interaction with local Federal agencies other than
the investigation of its sanitary waste system.
Solid waste is removed by a local disposal service. There is potential
for recovery of solvent and active ingredients from the wastewater system.
74
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CASE STUDY NO. 4
General Information
This plant, which first formulated pesticides in 1966, is located in the
East North-Central United States. The facility is owned by a large pesti-
cide manufacturer, although most of its production 0~ 95%) is done on
contract.
Production during the past 3 years has been essentially constant. Annual
production of liquid formulations (none of which are water-based) and
granules has been relatively small. Primarily, organophosphates, chlorinated
hydrocarbon pesticides, and spray oils are formulated.
This is a rather small facility, having only two liquid formulation units
whose capacities are 300 and 1,000 gal. No major modifications have been
made to these units since they were installed. Both the liquid lines as
well as the granule unit are conventional, batch units.
This plant is only operated about 9 months per year (one shift, 5 days per
week schedule). During the busy season (November through April), the plant
operates two shifts a day, 5 to 5-1/2 days per week. A total of 100 turn-
arounds are required during each operating season.
Most of the analytical control work is not done at this plant site. Rather,
samples are sent to one of the company's larger facilities for analysis.
Wastewater Characteristics
Total water usage at this facility during the peak production season is
about 27,000 gal. per month. The water is obtained from the local munici-
pal water system.
An earlier company study estimated 200 to 250 gal. per day of process waste-
water are generated. The process wastewater comes from three major sources:
equipment washout, plant washdown, and steam condensate. The granule and
liquid lines are washed out between production runs by using a minimum
volume of water, which is collected in the same sump as condensate from the
steam heating system. No analysis, however, has been made of this waste
stream.
Drums that have contained technical organophosphate material are filled
about one-fourth full with caustic solution. This water, however, is left
in the drums when they are taken to the landfill for disposal.
75
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Sanitary waste, which includes washwater from employee work clothing, goes
into the local sewer system.
Rainwater is carried by natural drainage into a local stream.
Spills of technical material are not washed down with water. They are
absorbed on clay, drummed, and disposed of with the other solid waste.
Wastewater Treatment System
The wastewater system used by this plant is depicted in Figure A-4. Both
of the liquid formulation units are located in a pit that drains to a small
collection sump. Washwater from the granule unit, which is located on
ground level, is also routed to the sump system. From the collection sump,
the wastewa'ter is pumped into a small holding tank located at ground level.
From the holding tank, the wastewater is periodically emptied into empty
drums.
All of the waste from this site (both solid waste as well as the drummed
wastewater) is transported to a local cut-and-fill dump where it is dis-
posed of for a fee of $2 per ton (liquid or solid). No criteria have been
specified for the liquid waste going into the dump.
The only direct cost for this system is the $2 per ton dumping fee and the
expense of purchasing and operating the truck to haul the waste.
Land value in this area ranges from about $800 per acre for agricultural
to $2,500 to $3,000 per acre for industrial areas.
76
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Granule
Formulation
Unit
Tt
f
Wastewater
Liquid
Formulation
Units
Wastewater
1
Holding
Tank
' Drums
Figure A-4 - Waste Handling System
77
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CASE STUDY NO. 5
General Information
This plant site formulates about 100 pesticidal products for sale under the
company's own brand name. It is located on about 18 acres of land in an
industrial section of a major metropolitan area. This independent formula-
tor is a major supplier of home and garden products for Mid-America.
Almost the complete range of active ingredients is formulated into liquids,
dusts, wettable powders, and granules.
Wastewater Characterisitics
In 1972, typical water consumption for this plant site was 20,000 gpd.
The water was used for sanitary waste, showers, boiler makeup, cooling,
water-based products, equipment washdown, and air cleaning equipment.
The contaminated wastewater from equipment cleaning and air pollution
control was about 3,000 gpd.
Analysis of effluent from the plant site in March 1972 showed the follow-
ing concentrations of toxicants:
2,4-D 28.5 to 1,190 mg/liter
2,4,5-T 3.91 to 162 mg/liter
Malathion 2.06 mg/liter
Methoxychlor 0.13 mg/liter
Revisions in the plant's operational procedure and production schedule have
allowed for a significant reduction in the quantity of toxicant-containing
wastewater produced. Equipment washdowns have been reduced to about 30
per year, yielding only about 60,000 gal. of washwater. This washwater is
now disposed of by spraying on the company property.
78
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CASE STUDY NO. 6
General Information
This formulation plant, which is owned by a large, diversified corporation,
produces about 5,000,000 gal. of formulated material each year, all prod-
ucts carrying other company labels. Included in the production figure is
a small volume of nonagricultural materials such as antifreeze that are
simply repackaged for sale. All types of ingredients are formulated, in-
cluding herbicides and insecticides. Both water and organic solvent for-
mulations are packaged, although mostly water-based products are produced.
The liquid formulation line in this plant is about 15 years old. The plant
runs most of the year on a one-shift basis; three shifts are operated dur-
ing the peak season. Water is obtained from the city. Usage during peak
production is about 300,000 gal. per month.
Wastewater Treatment
Major sources of toxicant-containing wastewaters are equipment washdown
and the waste from the quality control laboratory. This plant uses four
holding tanks to accumulate wastewater before analyzing and discharging
it into a local industrial district treatment system. Most runoff is also
channeled into this system. The district system consists of primary treat-
ment only.
The only requirements set by the industrial treatment system for discharge
of formulation waste into its treatment plant are:
Toxicant concentration <. 100 ppm
Total toxicants < 10 Ib/day
pH 6 to 8
This plant has had little difficulty in meeting these few requirements.
The rare occasion where these specifications can not be met is usually the
result of an unusual event, such as a spill. In this event, the wastewater
is transferred to storage for subsequent treatment or removed by a contract
disposal service to a state-approved landfill.
System Cost
This system utilizes the storage capacity of an abandoned secondary waste
treatment plant that had been used to process waste from a herbicide manu-
facturing plant. Capital cost data on the system, therefore, are not
meaningful. The operational costs charged against the operation of this
system are one-half of one operator's time (~ $3-4 per hr), and ~ $10 per
1,000-gal. load that is removed by the contract disposal service. Infre-
quently, the pH of the wastewater must be adjusted to meet the 6 to 8 range,
but the associated cost is not significant.
79
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CASE STUDY NO. 7
General Information
This plant is operated by a large agricultural chemical manufacturer to
formulate products for sale under the company's own label. The plant is
located in the West North-Central United States, and has been in operation
since 1955. This facility operates year round, and produces about
40,000,000 Ib of formulated products each year. Active ingredients used
include a number of thiocarbamate herbicides and organophosphate insecticides
No inorganics or metal-containing pesticides are formulated. Production
is about evenly split between liquid and granule products.
Wastewater Characterization
The primary source of process wastewater is equipment washout. Dye is used
for one of the major solid formulations, and is one of the main reasons for
water-washing. All water from inside the dikes that surround technical
material storage tanks also goes to the wastewater treatment system.
Effluent from the plant's wastewater treatment system has been analyzed
by the local municipality into whose sewer system the water is discharged,
and the quality of this water has been found to be acceptable. These
analyses, however, were not available.
Where possible, solvent is used to clean out formulation equipment in
order to minimize the volume of wastewater generated.
Wastewater Treatment System
The wastewater treatment in use at this plant site is depicted in Figure
A-5. The system is still considered to be in the pilot plant phase,
however, and for that reason complete design and operational data were not
available. A general description of the system is given below.
Wastewater from the production units is collected in a sump and is pumped
into a settling tank. Here, flocculating and deemulsifying agents are
added. The wastewater is then continuously pumped to a vacuum filter unit.
Sludge from the filter is disposed of with the other solid wastes. From
the filter, the water is pumped to an aeration tank for secondary treatment.
If necessary, water from the -aeration tank can be recycled to the settling
tank.
In the next step, the aerator effluent is passed through an activated car-
bon column and then into a 100-ft long x 6-ft wide "fish pond." The system
effluent can be discharged to a garden plot, the city sewer, or to a re-
cycling system.
80
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Liquid
Waste
Recycl
1
Sumps
t
Settling
Tank
— *»
Vacuum
Filter
— ^
Aeration
System
J
Cake to
Sanitary
Landfill
Recycle ^-
Garden «^-
City
Carbon
Absorption
Column
I
Holding
Pond
Figure A-5 - Pilot Absorption System
81
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The design retention time for the system is about 30 days. The carbon
column has been used up to 6 months between rechargings (about 540 Ib of
carbon). At the reported continuous flow rate of 2 to 5 gpm, a carbon
capacity of 500 gal. per Ib is indicated. This system has reportedly
operated for short periods at a rate of 15 gpm.
Specific data on the quality of influent and effluent water for this sys-
tem were not made available. However, data indicate that typical operation
yields a reduction in total toxicants from an initial concentration of
140 ppm to an effluent containing < 0.1 ppm.
The actual capital cost of this plant is not significant because of its
developmental status. Operational costs, however, are meaningful. This
system requires the full-time attention of two people to operate the
equipment and provide analytical services.
Miscellaneous Information
Solid waste is disposed of by shipping it to an approved landfill at a
cost of about $1.25 per cubic foot (including freight). The disposal of
drums and bags is not a problem as most technical materials are received
in tank cars or tote tanks.
82
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CASE STUDY NO. 8
General Information
This plant is located on a 2-1/2 acre site near a small Middle Atlantic
town. The facility, which first came on stream in late 1962, is owned
and operated by a large manufacturer of agricultural chemicals. The plant
operates all year, with peak production during the January through July
period. This is a one shift per day, 5 days per week operation except for
3 months in the spring when they operate 6 days per week. The plant work
force is seven full-time employees.
Production at this facility typically includes small volumes of solvent-
based liquid formulations (no water-based liquids), granules, and dust.
All of these products carry the company's own label. These products in-
clude a broad range of organophosphates, chlorinated hydrocarbons and
spray oil.
The plant facilities include two liquid formulation units, one granule
unit, and a dust unit. All four of these units are typical batch opera-
tions of small capacity. Major modifications have not been made since
1966.
The plant's production schedule requires a number of turnarounds per year:
50 for the two liquid lines, six for the granule system, and 100 to 120
for the dust unit.
Approximately 500 55-gal. drums are reconditioned each year. To each drum,
1 to 1-1/2 Ib of soda ash and about 1 gal. of water are added; the drums
are placed on their sides, and are allowed to stand for several days before
they are emptied. During this time, the drums are periodically rotated.
Most of the washouts are made during the peak production season. Water,
however, is generally not used to wash out the production units; solvent
is used, and where practical, is saved until the next production run.
About 50 gal. of water is required each time the granule system is cleaned
out.
Quality control samples are not analyzed at this site, but are sent to
another of the company's facilities for analysis.
Wastewater Characteristics
An on-site well is the source of water used at this plant. The consumption
rate has not been determined.
83
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All surface waters run off the plant site and eventually end up in a nearby
stream. This area's water table is at about 6 ft, and a drain tile system
has been installed.
Sanitary wastes from office and production areas go to two septic systems.
Washwater from work clothes processed on-site also goes into one of the
septic systems.
It is estimated that about 2,000 gal. of process wastewater are generated
each year. The major sources of the wastewater are building washdown
(approximately one time per year)_, granule unit turnarounds (approximately
six per year) and drum cleaning (~ 500 drums per year).
The process wastewater from this plant has not been analyzed, and therefore
no estimate of the toxicant content can be made. The volume estimate of
2,000 gal., however, was based on operating experience as well as knowl-
edge of the wastewater treatment system1s capacity.
Solid wastes are disposed of in a local landfill at no charge.
Wastewater Treatment System
Process wastewater from the formulation units as well as from the drum
washings is disposed of by evaporation. The system used is depicted in
Figure A-6. Wastewater from the liquid lines, from the granule unit, and
from the yearly building washdown go into a collection sump in the bottom
of the liquid line pit. From there, the wastewater is pumped into a 16-ft
long x 4-ft wide x 3-ft deep concrete evaporation pit. The water is
treated with soda ash to adjust the pH to 9, and is allowed to evaporate.
This evaporation pit is covered with a plastic roof, and contains a series
of burlap sheets that hang into the water to aid evaporation.
Washwater from drum decontamination is also emptied into this evaporation
pit.
No direct expenses are allocated to the operation of this system. The con-
crete pit was installed by plant personnel, and would cost about $1,000 to
duplicate today. About 57, of one person's time is required to monitor the
system's operation.
Land value in this area is about $8,000 per acre.
84
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Granule
Formulation
Unit
I Wastewater
Liquid
Formulation
Units
Figure A-6 - Wastewater System
85
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CASE STUDY NO. 9
General Information
This is one of the larger pesticide-formulating facilities in the country,
and is one of several plants operated by this company in the South. This
firm is not involved in the manufacture of pesticidal chemicals. Annual
production is estimated to be about 40 million pounds of dry and liquid
formulations. Much of this volume is custom-formulated for other companies
under their respective labels. The balance is formulated and marketed
under the company's own label. The custom-formulating work is done for
almost all major basic pesticide manufacturers in the country.
This facility, located in the West South United States, first started
operation in the 1950's as a dust-formulating plant. An air mill unit
for powder formulations was added in 1967, and liquid formulation units
were added in 1968.
The plant operates on a year-round basis producing a complete range of
products. About 40% of the products are insecticides, and 60% are herbi-
cides. Arsenical-based formulations are also mixed. The solid formula-
tion facilities include three air milling units. Long production runs
are made wherever possible.
There are several liquid units where 1,000-gal. batches can be run simul-
taneously.
Wastewater Characteristics
The primary sources of process wastewater from this plant site are equip-
ment washdown and the quality control laboratory effluent. Estimated
wastewater volumes are 1,500 to 2,000 gpd (average), with a maximum of
4,000 gpd.
At one time, the plant attempted to use a carbon filtration system to treat
process wastewater. This system included a pit 16 ft deep and 20 ft sq
which was filled with layers of limestone (4 ft), charcoal (1 ft), and,
on top, 4 more feet of charcoal. Wastewater from the entire plant was
sprinkled over the top of this filter bed, and eventually discharged into
a small stream. Use of this treatment system was discontinued, however,
before operational data were developed.
The following analyses were made of the effluent from this plant by a state
department of pollution control:
86
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1. Five 24-hr composite samples (1970) showed:
COD 483 mg/liter
Total solids 661 ing/liter
Dissolved solids 631 mg/liter
Arsenic 37 mg/liter
2. One grab sample (1971) showed:
DDT 62 rag/liter
DBF 14 mg/liter
Aldrin 0.21 mg/liter
Plus indication of Chlordane and Toxaphene
3. One 24-hr composite sample for conducting bioassay,
using bluegill, sunfish, and procedures according
to Standard Methods. 13th edition. The 48-hr Median
Tolerance Limit (MTL) was determined to be 0.023%
concentration of the wastewater (1971).
This plant is currently attempting to obtain permission to discharge its
effluent into the local municipal sewer system. Sanitary wastes are al-
ready going into this sewer system.
87
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CASE STUDY NO. 10
General Information
This plant is one of several owned and operated in the South by a pesti-
cide formulation company. This company does not manufacture pesticidal
chemicals.
A wide variety of products are formulated, including granule, liquid, and
powder forms of organophosphates, chlorinated hydrocarbons, and inorganics.
Total liquid production is about 3,000,000 gal. per year, about 25% of
which is water-based. Water-based formulations of MSMA/DSMA are produced.
A significant volume of solid formulations of proprietary pesticides are
produced for several of the major agricultural chemical manufacturers.
Wastewater Treatment
Process waatewater is being treated by a pilot plant carbon absorption
system. The wastewater is first collected in a 40-ft long x 22-ft wide x
4-ft deep, covered collection sump. From there the water is pumped into
a holding tank. The holding tank discharges into a carbon absorption
column made from three 55-gal. drums. No analytical data were available
on either the raw wastewater or the effluent from the treatment process.
88
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APPENDIX B
NATIONAL AGRICULTURAL CHEMICALS ASSOCIATION (NACA)
WASTE DISPOSAL MANUAL
89
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FOREWORD
The original NACA manual, "Waste Disposal," was developed by a special
NACA-Industry Committee (the Subcommittee on Waste Disposal of the Grady
Committee) in 1965. The intent of this manual was to provide guidelines
for the disposal of waste from pesticide manufacturing and formulation
operations. The "Grady Disposal Manual," as it became known, has received
wide use since its original publication.
In 1970, the Environmental Quality Committee of the NACA initiated efforts
to update the original disposal manual. Revised sections as well as new
data were developed by about 20 representatives of the agricultural chemi-
cals industry. Unfortunately, the Committee was not able to complete the
revision of the manual, and the new data on waste disposal have not become
available to the pesticide industry.
As part of this study of waste treatment technology for pesticide formula-
tors (Environmental Protection Agency Grant No. R-801577), data that had
been generated to update the "Grady Disposal Manual" were compiled, and
integrated into the format of the original document. The "updated" manual,
which follows, has been used during this study to help develop baseline
parameters, against which to evaluate treatment systems being used for
formulation plant wastewater.
This appendix has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the contents
necessarily reflect the view and policies of the Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
90
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TABLE OF CONTENTS
Introduction « • 92
Pesticides in the Environment 93
Pesticides in Water 93
Pesticides in Air 93
Regulatory Agencies 94
Pollution Control by Preventive Measures 95
Process Design 95
Waste-Treatment Buffer System 95
General Considerations • 99
Need for Treatment 99
Wastewater Analysis 99
Waste Treatment and Disposal Methods 101
Biological Treatment 101
Ponding HO
Burial HO
Incineration 112
Contract Services 118
Chemical Methods 120
Municipal Treatment 121
Deep Well Injection 122
Disposal of Specific Classes of Pesticides 124
Chlorinated Hydrocarbons 124
Organic Phosphates 125
Carbamate Pesticides 128
Dithiocarbamate Pesticides 130
Botanicals 131
Phenoxy Acids, Salts, and Esters 132
Inorganic Pesticides 134
Triazine Herbicides 135
Substituted Ureas 137
Chloroacetaraide Herbicides 138
Pesticide Container Disposal 140
References 141
91
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INTRODUCTION
The suggestions in this manual have been developed by a special NACA-
Industry Contnittee as guidelines which might be followed in the disposal
of waste from pesticide manufacturing and formulating operations.
Of necessity, these suggestions are expressions of opinion and are based
on practical experience and information correlated by researchers, opera-
tors, and executives who are qualified industry representatives. They
are not intended to supersede any manufacturer's or supplier's specific
instructions relative to individual products which may appear on the label
or be supplied to the fonnulator in some other manner. They are also not
intended to supersede any effective waste disposal practices now currently
followed by individual plants.
To the extent that Federal, State, and local regulations pertaining to
waste disposal exist, and require or prohibit certain practices, the sug-
gestions in this manual are intended as supplementary information only.
No guarantee or warranty is expressed or implied that adoption of the sug-
gestions herein will ensure compliance with applicable laws and regulations
pertaining to waste disposal.
In the preparation of this manual, a few classes of pesticides were selected,
for purposes of illustration, for specific discussion as regards waste dis-
posal practices. The fact that some pesticide or group of pesticides is
not mentioned in the manual should not be interpreted as indicating that it
presents no waste disposal problem. Most pesticides do present such a prob-
lem.
It is recommended that manufacturers and formulators of pesticides contact
their suppliers for specific information and suggestions on any waste dis-
posal problems which might be involved with the materials which they are
supplying. Attention is also called to the fact that there are professional
consultants on the matter of waste disposal.
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PESTICIDES IN THE ENVIRONMENT
Pesticides have been used for several decades and have been a major factor
in increasing the quantity and quality of man's food supply. It is only
recently that their use or misuse has raised serious questions as to whether
they are adversely affecting man's environment.
As of early 1965, the Pesticides Registration Division, U. S. Department of
Agriculture, had registered approximately 60,000 products containing one
or more of some 600 active pesticidal ingredients. Currently, about 32,000
products have Federal registrations from the Environmental Protection Agency.
These pesticidal chemicals are separated into three major categories: in-
organic; frequently so-called "natural" organic (or plant extracts); and
synthetic organic pesticides.
Pesticides in Water
Pesticides can enter ground and surface watercourses by several means:
direct application for the control of aquatic weeds, trash, fish, or aquatic
insects; percolation; and runoff from agricultural applications. The dis-
charge of industrial waste resulting from the manufacture of pesticides
and the discharge of wastewater normally used,for equipment cleanup have
also contributed in some instances to pollution. There have been documented
instances which indicate that effluents containing pesticides have damaged
or killed various species of vegetation and fish. Pesticides, when found
in water samples, are usually in very low concentrations. Although knowl-
edge is lacking regarding the long-range effects of most pesticides on our
water resources, it has been reported that these substances, with their
accompanying diluents and solvents, are entering our natural waters and
may have contributed to taste and odor problems. It is generally believed
that many of the formulations exhibit low threshold concentrations and the
tastes imparted are typical of the solvents used in the formulations.
There is a paucity of laboratory information regarding the threshold taste
and odor levels of organic pesticides.
The fate of the parent compounds of organic pesticides once they enter
water, regardless of whether they are biologically degraded, absorbed, or
chemically decomposed, is important. If the pesticide is of such type
that it would persist and affect water quality for a long time, additional
or special treatment may be required.
Pesticides in Air
Although air pollution control has been accelerating at a faster rate than
other environmental health disciplines, the matter of air pollution control
as it applies to the manufacture and formulation of pesticide chemicals
93
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imposes no major difficulties. The nature of the processes and the high
cost of the pesticidal chemicals used dictate that the material losses be
held to a minimum. To make the process economical and safe, dust collec-
tors, such as cyclones and bag collectors, are widely used throughout the
industry. Fumes are usually collected under a slight vacuum, condensed
and/or scrubbed in a packed tower or an equivalent gas/liquid absorption
type vessel which will clean the air. Solvents, when stripped from the
final product, can frequently be reprocessed (recovered) for reuse.
The unloading and storage of some chemicals give rise to occasional emis-
sion of vapors or odors. The use of a closed system will minimize these
losses. Vent losses of storage tanks can be controlled by connecting the
vents to the process scrubbing system. Effluents from the scrubbers may
require further treatment.
Regulatory Agencies
Air and water contamination, either by use or misuse of pesticides, can
best be controlled at the local level. With the increasing demands on the
part of everyone for a better environment, it is only logical to expect a
closer interest displayed by State, interstate, and Federal bureaus whose
responsibility lies in the field of pollution control. It is generally
believed, particularly by both industry and State regulatory agencies,
that pollution control is a complex technical problem which requires
thorough study and long-range planning on the part of competent personnel.
Industry recognizes the need for research and the need for highly technical
field studies dealing with air and water quality and long-range planning.
The importance of the support and assistance of local regulatory agencies
cannot be overemphasized. The disposal of processing waste and other
materials containing pesticides will depend to a great extent upon local
conditions. All local, State, and Federal regulations regarding health
and pollution must be followed. The official agencies involved are normally
the city or county health departments, and the State Department of Health
or the State Water Pollution or Water Resources Commissions. The materials
supplier is also a good source for this information.
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POLLUTION CONTROL BY PREVENTIVE MEASURES
During'the manufacture and formulation of agricultural chemicals, loss pre-
vention, containment, recovery, and in some cases treatment of intermediate
by-products and product losses, are of great concern.
The greatest potential for preventing air or water pollution in the manu-
facture of agricultural chemicals can be divided into two categories, each
of which can be incorporated into the initial design of a plant. Such
incorporation provides means for controlling potential pollutants before
they reach the waste treatment system.
Process Design
It is apparent that pollution control can best be accomplished by a posi-
tive waste prevention and recovery program in the processing plant. In
essence, this places a portion of the waste treatment system into the waste
generating plant, a location where the operation of the recovery equipment
is usually a money-making rather than a money-losing operation. It is
much easier to contain and recover material from a single waste source
which is at a minimum volume, rather than recover or treat large volumes
of mixed wastes. Table B-l lists some examples of prevention, control,
and recovery measures that can be incorporated into the design of a new
plant.
Waste-Treatment Buffer System
Experience has shown that a buffer unit, placed between the processing
plant and the final waste treatment unit, is a very effective source of
control, equilization, and stabilization. This buffer unit should be of
sufficient size to contain releases of product or intermediates due to mis-
operation or accident, without increasing the feed quantity to the final
waste treatment unit. If the maximum buffer capacity of the intermediate
unit is reached, the waste-generating plant must be shut down, rather than
exceed the design loadings of the final treatment plant. For example, a
large receiving pond provides an equalization buffer against shock loads
of waste material before final treatment. The buffer unit also serves as
a trap so that high losses can be given additional or different treatment.
An example of a buffer system would be a sump equipped with a sump pump
connected to a dumpster, with no sewer overflow connections. This system
provides time and opportunity to make additional judgments in disposal of
unexpected losses. Perhaps the buffer unit can be called a Fail-Safe Unit,
since its greatest asset is to function properly during abnormal conditions.
These units help ensure better and surer correct handling as compared to
sewer samplers or alarms, which can break down, be turned off, or ignored.
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TABLE B-l
METHODS FOR WASTE PREVENTION. CONTROL AND RECOVERY
Method
Record prints
Raw material
purity
Curbs and sumps
Distillation
Washing
Shell and tube
condensers on
steam jets
Comment
Records of all sewers, sewer junction boxes,
valve boxes, all underground lines, are bene-
ficial in tracing and controlling waste losses.
As a general rule, the purer the raw material,
the less the potential for waste. Some wastes
are made up of impurities; they combine with
other raw materials or other impurities to give
additional by-products, which may be greater
pollutants than either.
Curbs and collecting sumps around pumping areas
and transfer tanks can collect pump drippings
and accidental losses. The lost material may be
returned directly back to the process.
Distillation is not only an effective method
of obtaining product purity, but collects higher
boiling residues in a relatively small volume
of burnable bottom tars.
During washing of products or intermediates
in processing steps, the wash water might be
acidified slightly or salt added, to minimize
organic solubility (if permissible on the basis
of the chemistry involved).
The use of a shell-and-tube condenser for the
exhaust of a steam jet (operating on a still,
for example) is recommended over a direct
water-quench condenser for several reasons.
First, the condensate volume is about 1/100
that of the direct-quench condenser, plus the
fact that this allows for a higher organic
concentration, allowing for phase separation
in some cases, or easier disposal.
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TABLE B-l (Concluded)
Method
Phase separation
Filter cakes
Bag filters
Recirculating
scrubbers
Settling tanks
Cleaning
Drain tile
Operating
instructions
Comment
When wastewater is separated from product
in decanting tanks, a bull's-eye sight glass
should be located well ahead of the final valve
so as to prevent carryover of product with the
water.
Some filter cakes can be steamed on the filter
press to remove absorbed product.
Where bag filters can be used on contaminated
air, they are preferred to water scrubbers in
that the material can be recovered if of value,
or it can be destroyed by burning if small
volumes are involved.
A recirculating scrubber is preferred to a
continuous pass scrubber in that concentration
buildup is possible, making recovery feasible
or disposal much more efficient.
Settling tanks, of the proper size, are effec-
tive in removing entrained, insoluble contaminants.
Brooms or industrial vacuum sweepers should be
used to pick up spills of dry materials, rather
than hosing down.
Drain tile, connected to a collecting
sump, can be an effective aid in providing an
interception system for chemical contaminants
that have soaked into the ground.
Each operation should have carefully written job
procedures for each operation that include
specific instructions on the minimization of
waste as well as on the correct ways of disposing
of waste for each operation.
97
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It is evident that these described categories use the most direct route to
minimize pollution. Final treatment of some sort will be necessary. It
should be recognized that the purpose of final treatment is to treat this
irreducible minimum waste, and not wastes due to poor operation.
Active pursuance of these concepts will result in minimum waste that will
require processing, thereby minimizing cost and pollution.
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GENERAL CONSIDERATIONS
The methods of waste treatment and disposal that are generally used for in-
dustrial wastes have application to, or can with modification be employed
for, pesticide plant wastes.
Within limits, there are treatment processes available that are versatile
enough to remove almost any impurity that is considered harmful. However,
the unit operations and processes that are called upon to achieve this ob-
jective may be complex, and several may have to be used in series. From
a technical point of view, a means probably exists for removing a contami-
nant; the problem is reconciling the cost of removal with the necessity
for achieving minimum contamination of the environment.
Need for Treatment
Some compounds are objectionable in small concentrations in water for
several reasons. Principal among these reasons are:
• Potential toxicity to wildlife, fish, and man.
• Tainting of fish flesh.
• Taste and odor.
Wastewater Analysis
Waterborne wastes are characterized in part by reference to physical and
chemical properties. The more common of these are:—'
• Biochemical Oxygen Demand (BOD) - That amount of dissolved
oxygen which is utilized by microorganisms in stabilizing organic matter
that can be consumed or metabolized. The test is performed by incubating
an appropriate volume of the waste sample with oxygen-saturated dilution
water under test conditions of 5 days at 20°C (68°F), unless specified
otherwise. The test is a bioassay.
• Chemical Oxygen Demand (COD) - That amount of chemical oxidant
which is consumed by reacting a waste sample under given laboratory con-
ditions (usually 2 hr refluxing with dichromate in a 50% sulfuric acid
medium, and determination of the oxidant remaining after this treatment).
• Suspended Solids - That quantity of particulate matter that is
retained upon filtration of a given volume of the wastewater.
99
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• pH - The intensity of acidity or alkalinity present. pH limi-
tations are imposed, for example, to protect concrete sewers, ensure the
effectiveness of waste treatment processes, and protect aquatic life in
receiving watercourses. A permissible range of 5 to 9 is typical for
plant effluents.
• Dissolved Oxygen (DO) - That quantity of oxygen present in
solution.
• Others - Occasionally, additional properties are considered,
and these may include temperature, color, dissolved gases, dissolved solids,
and chlorine demand.
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WASTE TREATMENT AND DISPOSAL METHODS
This section contains brief descriptions of treatment methods that can be
used for pesticide wastes. The applicability of these techniques to spe-
cific pesticides or to individual classes of pesticidal chemicals is not
discussed in this section, but is reviewed in the section immediately
following.
Biological Treatment
Wastewaters containing decomposable organic matter exert a demand for dis-
solved oxygen when discharged into a watercourse. If the oxygen demand
exceeds the rate of replenishment from the atmosphere and by photosynthe-
sis, the dissolved oxygen in the watercourse becomes depleted. Anaerobic
decomposition takes place with the evolution of gases, and nuisance condi-
tions and foul odors result.
Biological treatment of wastewaters for removal of organic matter prior to
discharge to a watercourse may be accomplished either aerobically (oxygen
present) by use of trickling filters, the activated sludge process, oxida-
tion ditches, aerated lagoons and oxidation ponds, or by anaerobic (oxygen
absent) digestion. In each of these processes, the organic matter is used
as an energy source (i.e., food) by microorganisms present in the waste-
water and is converted to innocuous forms in an artificial environment and
under controlled conditions.
Trickling Filter. The trickling filter or bio-filter is a packed bed of
media over which wastewater is distributed from fixed or movable nozzles,
or sprays. As the wastewater trickles through the media, the biological
organisms present cling to the media surface and a slime growth develops.
Using oxygen supplied by natural or induced means, organic matter present
in the waste which is subsequently added is adsorbed and oxidized by the
slime growth.
Filter media may be either random-packed blast furnace slag, crushed
granite, limestone or traprock, or an engineered plastic material placed
on a false bottom consisting of perforated filter blocks or grating and an
under-drainage system. Rock filters contain 2-1/2 to 4 in. rock packing
and vary in depth from 3 to 8 ft. Plastic packings, due to their light
weight and greater surface area per unit of volume, are employed in depths
up to 40 ft. Filters using plastic media are sometimes referred to as
"oxidation towers."
Trickling filters are usually followed by a settling basin. The function
of the settling basin is to remove the large masses of biological growths
which intermittently "slough off" the filter media.
101
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Where wastewaters contain a widely variable organic loading, trickling
filters have been used ahead of an activated sludge system. This type
of filter is often referred to as a "roughing filter." Using the trick-
ling filter's inherent ability to absorb shock organic loadings with only
a minimum loss of efficiency, the roughing filter reduces the loading to
the polishing or second stage biological process.
For intermediate and high-rate filters, a portion of the wastewater which
has passed through the filter is recycled for another passage through the
filter for increased organic removal and to maintain a continuous loading.
A settling basin is generally employed ahead of the trickling filter where
an economically justifiable proportion of the organics can be removed in
this manner.
A typical trickling filter layout is shown in Figure B-l.
Activated Sludge. In the activated sludge process, the biological slimes
are produced within the wastewater itself. The biological masses are
either generated about suspended particles, or they are constructed of
colonial growths of bacteria and other living organisms. The microorganisms,
or activated sludge, multiply rapidly when maintained in contact with the
organic matter present in the waste in an aerobic environment. As a result,
the organic matter is rapidly oxidized, while the activated sludge tends to
coagulate and form a precipitate that is readily settleable.
The two methods that are in general use for aerating the mixture of sewage
and activated sludge (mixed liquor) are diffused air aeration and mechani-
cal aeration. The former is accomplished by forcing compressed air into
the wastewater through a diffusion device at the bottom of the aeration
tank creating a bubbling action. As the bubbles rise to the surface, oxygen
transfer occurs at the bubble/water interface. In mechanical or surface
aeration, the wastewater is constantly stirred and exposed to the atmo-
sphere. In some instances, a combination of air diffusion and mechanical
aeration is used.
There are a number of modifications of the activated sludge process.
Among these are: conventional activated.sludge, extended aeration, contact
stabilization, step aeration, tapered aeration, and high-rate activated
sludge. Only the first three modifications, the most widely used, are
discussed herein.
The conventional activated sludge process is the most commonly used, par-
ticularly for larger plants since it offers the best compromise between
treatment efficiency and capital and operating cost. A schematic illustra-
tion of the process is shown in Figure B-2.
102
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PESTICIDE
PLANT
o
co
•NEUTRALIZATION
TANK
ROTARY
DISTRIBUTOR
I FINAL
EFFLUENT
WASTE SLUDGE
TO DIGESTER,
DEWATERING DEVICE
AND SANITARY
LAND FILL OR
INCINERATOR
TRICKLING
FILTER
FINAL
CLARIFIER
Figure B-l - Wastewater Treatment by Trickling Filter
-------
PESTICIDE
PLANT
00
O
•NEUTRALIZATION
IT TANK
WASTE
ACTIVATED
SLUDGE
WASTE SLUDGE
TO DIGESTER,
DEWATERING DEVICE
AND SANITARY
LAND FILL OR
INCINERATOR
•RETURN ACTIVATED
SLUDGE
ACTIVATED SLUDGE
AERATORS
Figure B-2 - Wastewater Treatment by Conventional Activated Sludge
-------
In the conventional process, clarification ahead of the aeration tank is
generally practiced. Up to one-third of the organic matter present in the
wastewater may be removed in this manner. Following aeration of the set-
tled waste (usually for 6 to 8 hr), the aerated mixture is withdrawn to a
final settling tank in which the activated sludge floe is separated by
gravity, leaving a clear liquid for discharge to the watercourse. The
greatest portion of the settled activated sludge is returned to the aera-
tion tank (return activated sludge) to aid in the treatment of more waste-
water. The remainder is wasted in order to prevent a buildup of solids in
the aeration tank. Settled activated sludge is wasted by returning it to
the inlet of the primary settling tank where it is resettled with the in-
coming raw sludge for ultimate disposal.
In the extended aeration process, organic removal is achieved by continu-
ous aeration, generally for 24 hr. Since tankage requirements would be
high for large volumes of waste, this process is generally restricted to
use only at smaller installations.
Stabilization of wastes in the extended aeration process takes place in
two stages. During the first stage of aeration, as in the conventional
process, the biological organisms adsorb and oxidize the available organic
matter. In the second stage, the biological cells formed undergo self-
oxidation for further energy. Following aeration, the effluent is with-
drawn to a final settling tank in which the sludge floe is separated by
gravity. As in the conventional process, the greatest portion of the
sludge is returned to the aeration tank and the remainder is wasted.
Since only a portion of the biological sludge is nonbiodegradable, the
quantity of waste sludge is minimized. Primary settling preceding ex-
tended aeration is not practiced.
In the contact stabilization process, organic removal is achieved by per-
forming the two stages of stabilization previously discussed in separate
aeration basins. In the first, the aeration period is maintained such
that little or no oxidation of organic matter adsorbed onto the biological
organism takes place. Effluent from this basin is then settled. A portion
of the biological sludge is transferred to the second aeration basin where
stabilization or reduction by oxidation occurs. Effluent from this tank
containing the partially oxidized sludge is recycled to the first aeration
basin. Sludge not returned to the stabilization basin is wasted. The
degree of organic removal obtainable with the contact stabilization pro-
cess is less than that of the conventional and extended aeration processes.
Tankage volume requirements are smaller, however. Primary sedimentation
is not used with this process.
Prefabricated, "package" treatment facilities utilizing either the extended
aeration or contact stabilization process are available from several equip-
ment manufacturers in sizes up to 1.5 million gal. per day.
105
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Oxidation Ditch. The oxidation ditch is basically an extended aeration
modification of the activated sludge process, characterized by a design
retention time of at least 24 hr. A schematic layout of the process is
shown in Figure B-3.
The aeration basin consists of an earthen or paved oval-shaped ditch in
the form of a racetrack. Oxygen is suppled by a so-called brush aerator
which also circulates the mixed liquor.
Final settling and returning and wasting of sludge is similar to the ex-
tended aeration process. Where sufficient, suitable land is available,
the oxidation ditch offers an economical method of treatment.
Aerated Lagoon. An aerated lagoon is a basin of significant depth (6 to
12 ft) in which oxygenation is accomplished by mechanical or diffused aera-
tion units and by induced surface aeration. The turbulence level main-
tained in the basin ensures distribution of oxygen but is usually insuffi-
cient to maintain solids in suspension. As a result, most inorganic sus-
pended solids and biological solids which are not oxidized settle to the
bottom of the basin where they undergo anaerobic decomposition. Need for
removal is usually infrequent (10 years or more). The basin can be modi-
fied to include a separate sedimentation compartment to yield a more
highly clarified effluent.
Detention time provided in the lagoon is a function of the degree of or-
ganic removal required and the rate at which it may be biodegraded. Since
the organic removal rate is dependent on the liquid temperature, winter
conditions are used in sizing the basin. Detention periods of 10 days are
not uncomnon. Because of this, use of aerated lagoons is generally re-
stricted to applications where land availability is not a problem.
Aeration devices may consist of either platform mounted or floating me-
chanical surface aerators or submerged porous pipes of diffusers supplied
with compressed air.
Basins for aerated lagoons can be of almost any size, shape and material.
Walls can be vertical or sloped, concrete, stone rip-rap, paving or earth.
Where there is a potential for contaminating groundwater by seepage, the
lagoon must be lined with a plastic film, asphalt, concrete or certain clays.
A schematic layout of a typical aerated lagoon installation is given in
Figure B-4.
Oxidation Pond. An oxidation pond or waste stabilization lagoon is a large
shallow pond usually 2 to 4 ft deep in which wastewater is stored under
climatic conditions, namely warmth and sunshine, that favor the growth of
algae. Bacterial decomposition of waste matter releases carbon dioxide,
106
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NEUTRALIZATION
TANK
FINAL
EFFLUENT
FINAL INFLUENT
INFLUENT
RETURN SLUDGE
,^ BRUSH
/ AERATOR
WASTE SLUDGE—J
TO HOLDING
TANK OR
DRYING BEDS
OXIDATION DITCH
Figure B-3 - Wastewater Treatment by Oxidation Ditch
-------
o
oo
PESTICIDE
PLANT
00
o
rH^— NEUTRALIZATION
IT TANK
INFLUENT-
or,
\£— AFRATOR
AERATORS
I 1 1
FINAL
EFFLUENT
SETTLING
BASIN
AERATED LAGOON
Figure B-4 - Wastewater Treatment by Aerated Lagoon
-------
and heavy growths of algae develop. By photosynthesis the algae use the
carbon dioxide and inorganic minerals produced by the bacteria and convert
them into new cell mass releasing oxygen in the process. Combined with
the oxygen obtained by atmospheric reoxygenation induced by wind currents,
the bacteria oxidize the organic matter. Organic matter which settles to
the bottom of the pond (as in the aerated lagoon) is stabilized anaero-
bically. Ponds which combine aerobic and anaerobic stabilization are
termed "facultative ponds."
Deep oxidation ponds (10 to 12 ft) stabilize waste primarily by anaerobisis.
These ponds may be extremely odorous due to the gases created in the decom-
position.
Since oxidation ponds rely on natural oxygenation and mixing, the organic
loading which may be applied per unit of area is small. As a result, de-
tention requirements and consequently land requirements are high. Ponds
should have sufficient capacity to hold the maximum amount of rainfall as
well as the maximum amount of wastewater. Evaporation and seepage must
also be considered in determining the required pond capacity. Seepage
may be controlled in a similar manner as for aerated lagoons.
Anaerobic Digestion. Anaerobic digestion is a commonly used method for
disposal of concentrated organic solids removed from primary settling
tanks and excess biological solids from trickling filters or the activated
sludge process. Decomposition of the organic matter results from the ac-
tivities of two major groups of bacteria. The first convert the organic
matter to organic acids and the second convert the organic acids to methane
and carbon dioxide gas. The kinetics of anaerobic decomposition are slow
and as a result long detention periods are required to achieve a substan-
tial reduction of organic matter. In order to shorten the detention period,
the digester contents are often heated to increase biological activity.
Anaerobic digestion is usually performed in a circular tank with either a
fixed or floating cover. Floating covers are used to store the gases pro-
duced which are combustible and may be used as a fuel for heating and
mixing the digester contents. Mixing and recirculation of the contents
are provided to evenly distribute the incoming raw sludge food for optimum
contact with the microorganisms, to maintain consistency and to prevent
buildup of scum and heavy bottom deposits. Drawoffs for removal of liquid
supernatant, scum and stabilized sludge are provided.
In some cases, anaerobic digestion is performed in two tanks. The first
is used for gasification and stabilization and the second for separation
of the stabilized solids from the liquid.
109
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Due to the long detention periods and large tankage volumes required,
anaerobic digesters are generally sized to provide only an intermediate
degree of stabilization of organic matter. The partially stabilized
sludge may then be ultimately disposed of by drying on filter beds, de-
watering by mechanical means for use as sanitary landfill or by incineration.
Ponding
A natural earthen depression or excavated pit can serve as a pond. The
distinction between a "pond" and an "oxidation pond" is somewhat arbi-
trary, but refers to function or the processes that take place therein.
No effort is made to exclude the entry of toxic materials into a pond, and
the purification that results is due to chemical reactions, physical stor-
age, and solar evaporation (provided there is a net loss of water; i.e.,
the total evaporation exceeds the total precipitation).
The capital costs for a pond are much less than those for accelerated bio-
logical treatment systems (trickling filters and aeration tanks), particu-
larly if land prices are reasonable, and operating costs can be much less,
too. Some disadvantages of ponds are:
• There is a potential for contaminating groundwater. This can
be minimized by lining the bottom with plastic film, asphalt, certain
clays, or concrete, but this adds to the first cost.
• There is a potential for producing undesirable odors. If bio-
logical conditions prevail, all the oxygen dissolved in the water may be
utilized and hydrogen sulfide can result.
• There is a potential for chemicals in the pond to produce
odors.
• Water-holding capacity. Ponds should have sufficient capacity
to hold the maximum amount of rainfall as well as the maximum amount of
waste chemical to be impounded. Evaporation, seepage, and annual rainfall,
as well as the volume of waste to be handled, must be considered in deter-
mining the capacity of a pond.
Burial
Solids and trash may be disposed of by burial in an approved landfill,
either in drums or packages, or in bulk, depending upon the material and
the distance to a burial site. Sanitary landfill is the process of de-
positing refuse on the ground, usually in a depressed area, by compacting
it thoroughly and covering it within 24 hr with approximately 24 in. of
earth or equal material. This process "fills" the "land" and normally is
"sanitary" from a public health point of view.
110
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Land Availability. The availability of land which would benefit from a
sanitary landfill operation is an important consideration. The materials
should either be stable or of such nature that they become stable in the
environment produced by burying. Unless the quantity of refuse to be
disposed of is sufficient to fully utilize at least a single piece of
digging, moving, and compacting equipment, the economics may be unfavorable.
Pollution Potential. A sanitary fill must not be used if there is any
possibility of polluting either surface or groundwater supplies. Rela-
tively insoluble substances can still dissolve or leach into groundwater
and this fact must be given critical attention. Thorough compaction and
proper surface drainage, however, minimize the possibilities of water
leaching through the refuse.
Choosing Mechanics of Operation. After the limitations of a landfill
have been considered and its feasibility seems attractive, the mechanics
of operation demand attention. There are two general types—the trench
method and the area method.
* The trench method. The trench method is used normally where
the grade of the area to be filled is not exceptionally lower than adja-
cent land. Usually a bulldozer or front end digger is used to make trenches
between 4 and 12 ft deep and 15 to 40 ft wide. The dirt removed from the
trench is used as cover after the deposited refuse is thoroughly compacted.
The same tractor compresses the refuse by riding back and forth over it
after it is deposited.
• The area method. The area method of landfill is employed where
land that is used is at an elevation considerably lower, over a fairly
extensive area, than the surrounding land. Normal equipment is the back
hoe, clam shell, or dragline bucket. This type of equipment can stand on
solid high ground adjacent to the fill area and reach into the low area.
Compaction is accomplished by dropping the bucket on the deposit.
Landfill Precautions. Other specifications and precautions, although im-
portant collectively, are minor compared to the one item upon which a
successful operation is dependent; and that is, a sanitary landfill opera-
tion must be considered an engineering project. Careful planning must be
followed by constant high-quality supervision.
Special Landfills. The use of a "specially designated landfill" is the
procedure recommended by the Environmental Protection Agency for disposal
of small quantities of certain classes of pesticides\"L<
"Specially designated landfill" means a landfill at which complete
long term protection is provided for the quality of surface and
111
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subsurface waters from pesticides, pesticide containers, and
pesticide-related wastes deposited therein, and against hazard
to public health and the environment. Such sites should be
located and engineered to avoid direct hydraulic continuity
with surface and subsurface waters, and any leachate or sub-
surface flow into the disposal area should be contained within
the site unless treatment is provided. Monitoring wells should
be established and a sampling and analysis program conducted.
The location of the disposal site should be permanently recorded
in the appropriate local office of legal jurisdiction. Such
facility complies with the Agency Guidelines for the Land Dis-
posal of Solid Wastes as prescribed in 40 CFR Part 241.
Burial should not be used for the disposal of wastes unless:
• The landfill operation will not pollute either surface or sub-
surface water supply because of the location chosen.
• The nature of the material to be disposed of is such that dis-
posal by this method is economical, environmentally acceptable, and does
not lead to loss of materials which should be salvaged.
• The chemical and physical properties of the bulk of the waste
to be disposed of are of such a nature that they can be safely compressed.
• A sufficient quantity of the waste to be disposed of exists so
that a landfill operation of sufficient size to achieve economy can be made.
• An adequate amount of suitable land for the operation is avail-
able.
• The ultimate use of the land used for the fill will benefit
from the fill operation.
Burial is, or can be, a relatively economical method for disposing of many
types of industrial waste and trash in a sanitary nonnuisance manner where-
in both public and employee relations are improved. In some cases, re-
claiming of submarginal land results.
Incineration
Incinerators have been used for many years for the disposal of municipal
refuse and garbage, and recently a number have been built specifically to
handle chemical wastes efficiently and safely. In the simplest concept
incineration amounts to burning a substance to yield the harmless gases,
carbon dioxide and water vapor, together with more or lesser amounts of
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residual ash. The application of this operation to the disposal of pesti-
cides, however, is subject to complicating factors.
For complete destruction of these materials, combustion must be conducted
at about 1800°F with a residence time of one to several seconds at this
temperature. The vapors generated can be toxic if the combustion is in-
complete and, perhaps more often than not, they include acid constituents.
With some pesticides the residual ash presents yet another disposal problem.
A schematic diagram of one facility capable of incinerating pesticide
wastes is shown in Figure B-5. The major considerations involved in the
design of such a facility are discussed in the following section.
Character and Quantity of Wastes. Materials exhibiting pesticidal proper-
ties number in the hundreds, and formulations containing one or more of
these materials number in the thousands. Pesticidal chemicals may be
classified in major groupings as inorganic, organic, and botanicals or
"natural" organic materials. The inorganic group includes sulfur and
phosphorus compounds, borates and chlorates, arsenicals, mercurials and
other heavy metal derivatives. The botanicals include materials such as
rotenone and pyrethrum. The organic group of materials also includes
salts and metal derivatives as well as many compounds containing one or
more of the following elements: , sulfur, phosphorus, nitrogen, chlorine,
bromine and fluorine. Frequently encountered materials in the latter
category include:
2,4-D (isooctyl ester of 2,4 dichlorophenoxyacetic acid)
Picloram (potassium salt of 4-amino-3,5,6-trichloropicolinic
acid)
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine)
Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea]
Trifluralin (a,Q',Q'-trifluoro-2,6-dinitro-N,N-dipropyl-
j>-toluidine)
Bromacil (5-bromo-3-sec-butyl-6-methyluracil)
DSMA (disodium methanearsenate)
DNBP (alkanolamine salt of 4,6-dinitro-p_-sec-butyl-phenol)
Dicamba (2-methoxy-3,6-dichlorobenzoic acid)
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Liguid Wostes from Plant
Storage
Separate Tanks for
High and Low
Melting-point Liquids
Strainer
Burning
Tank
Relief
Stack
(Closed
During
Operation)
Tempering
Air Blower
10-000
cu.ft./min.
25 hp.
Venturi Scrubber Lined with
Acid-resisting Plastic
I
\
\
Fresh
Water
300gpm
Recycled
Waste
Water
1,000 gpm
Stock 100ft. High
6ft.6in. I.D.
4 ft.6 in. I.D. Outlet
Lined with Acid-resisting
Plastic
Recycled
Waste
Water
1,300gpm
Tar Burner
Atomizing
Air Blower
Combustion Air Blower
13,000 cu.ft./min.
75 hp.
Total Air, 26 Ib./lb. Waste
Waste Tar:Avg. lOgpm.
13,000 Btu./lb.
Temperature 80-100C.
Viscosity 150 SSU.
Tempering
Air Blower
10,000
cu.ft./min.
25 hp.
5 psi Feed
4 Burners, Combination
Gas and Tar Nozzles
5/16 in. Orifice
Water
240 gpm.
pH 1.0
Water
2,300 gpm
pH 1.0
Induced-draft Fan
2,600 Ib./min.
45,000 cu.ft./min.
600 hp.
To Wastewater-treatmenf Plant
for Neutralization, Clarification ,
and Recycle.
Figure B-5 - Waste-Tar Burner
-------
Dalapon (sodium salt of 2,2-dichloropropionic acid)
Paraquat (l>l-ditnethyl-4J4-bipyridylium salt)
Vernolate (s-propyl dipropylthiocarbamate)
2,4,5-T (trichlorophenoxyacetic acid)
Carbaryl (1-napthyl N-methyl carbamate)
DDT (dichlorodiphenyl trichloroethane)
Dieldrin (hexachloroepoxyoctahydro-endo, exo-di-
raethanonaphthalene)
Malathion (0,0-dimethyl dithiophosphate of diethyl
mercaptosuccinate)
IMA. (phenyl mercuric acetate)
Zineb (zinc ethylenebisdithiocarbamate)
Nemagon (1,2-dibromo-3-chloropropane)
Considering that pesticide waste disposal problems will be met by the
applicator, distributor, formulator, and manufacturer, it is obvious that
requirements and quantity aspects will cover a very broad spectrum. The
problems can range from the disposal of empty containers and the dis-
position of material from minor spills and broken containers all the way
to containment and destruction of highly toxic vapors and wastes from
manufacturing operations, which can involve tonnage operations.
Collection and Identification of Waste Materials. Wastes should be col-
lected in suitable containers, properly labeled for transfer to incinera-
tion, unless of course, the incinerator is an integral part of a manufac-
turing or formulating operation. Depending upon quantity, containers
should preferably be metal pails, drums- or tanks, or in some instances,
fiber packs if the wastes are dry solids. Identification should include
trade name, type of material, active concentration, weight. If the wastes
are solids, the unit quantity will need to be compatible with the incinera-
tion facility. If the wastes are liquid and represent a continuing and
sizable consideration, receiving tanks at the incineration site will be
necessary for proper segregation and blending.
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Selection of Incineration Facilities. With few exceptions, facilities
required for the proper incineration of pesticides cannot be justified
for small-scale operations. The applicator, distributor, and many for-
mulators will find it expedient to contract for the services of a munici-
pal or commercial incinerator equipped to meet all governmental regula-
tions .
For the incineration of flammable liquid wastes in those cases where a gas
scrubber is not required it may be quite satisfactory to mount an oil
burner and refractory burner block (such as supplied by National Aeroil
Burner Company) on a pedestal 'in the open with or without a pile of rubble
as a "target." Conventional vertical refractory lined incinerator units
capable of handling liquids having a high water content and operating at
rates up to several thousands of pounds per hour are supplied among others
by Thermal 'Research and Engineering Corporation, John Zink Company, Prenco
Division, Pickards Mather and Company, and Surface Combustion Division,
Midland-Ross Corporation.
Present practice in the combustion of solid wastes employs multiple-
chamber incinerators wherein the combustion proceeds in two stages. The
primary or solid phase combustion occurs in an ignition chamber which is
followed by a secondary or gaseous phase occurring in a secondary combus-
tion zone. Heat release is ordinarily in the range of 25,000 to 50,000
Btu per hour per cubic foot of combustion volume. The Bigelow/Phillips
Incinerator represents a large-scale application of this configuration.
The "Cleanaire Radicator" furnished as a package unit by the Midland-Ross
Corporation has a capacity of several hundred pounds per hour and with
adaptation for vapor scrubbing might be suitable for pesticide formulation
or small-scale manufacture.
For large-scale operation a rotary kiln incinerator has certain advantages,
among which is the ability to handle a large variety of feed including
packs and drums of solid waste chemicals. The Dow Chemical Company oper-
ates an incinerator of this type and a Dow subsidiary has designed a simi-
lar installation for another company.
A further type of incinerator coming into prominence is the fluid bed unit
which has special application when an inorganic residue such as sodium
sulfate or sodium chloride will be produced. Dorr-Oliver and Copeland
Systems, Battelle Memorial Institute, the Dow Chemical Company, and others,
have been active in this field.
Fumes and air-dispersed mists can be incinerated in equipment similar to
that used for liquids. The concentration of combustible contaminants will
usually be well below the lower limit of flammability, but it may be pos-
sible to pass the entire stream through a burner after adding a small
116
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amount of natural gas as auxiliary fuel and adjusting the air to effect
complete combustion. Fuel oil can, of course, be accommodated as supple-
mentary fuel in fume incinerators as well as in any other type.
The two most critical factors in incineration are temperature control and
retention time. The incinerator must be capable of maintaining a set
temperature with minimal fluctuation. Retention time is fixed by operating
parameters such as amount of excess air and by the volume of the combustion
chambers which should be large enough to provide several seconds residence
for the gaseous products of combustion. The temperatures required for the
complete destruction of most pesticides will be about 1800°F. An exten-
sive study in this regard has been reported by M. V. Kennedy, et al.,—'
as a contribution from the Mississippi Agricultural Experimental Station
under a grant from the U. S. Department of Agriculture.
Conventional fuel oil burners are used for burning waste liquids. All the
air necessary for combustion can be supplied as primary air, or primary
air may be used to control flame character while secondary air is introduced
through openings in the burner block to provide additional requirements
for complete combustion. To achieve proper burning, the waste liquid, or
supplemental fuel when required, must be finely atomized. High-pressure
air atomization, low-pressure air atomization, steam atomization and me-
chanical atomization have all been used satisfactorily.
Temperatures in the separate combustion zones are controlled by strategi-
cally located thermocouples which cause fuel (or waste) and air flows to
respond to the temperature settings. Draft gauges, flowmeters, and stack
gas analyzers are most useful in properly controlling incinerator operation.
Ignition and flame detection systems operating in conjunction with purge
arrangements and other safety features and interlocks are necessary acces-
sories which should be provided in a manner to meet Factory Insurance
Association requirements.
Liquid wastes are strained, segregated and blended as necessary and are
preheated if required for proper atomization in an oil type burner. The
feed pump should be a positive displacement type such as a vane, gear or
screw pump and it should be equipped with a variable speed drive actuated
by furnace temperature control. When handling solids, it is likely that
provisions would be made for directly injecting pails and drum quantities
of solid wastes into the incinerator. Typically, refuse other than full
drum or pails would be dumped into a refuse pit from which an overhead
hoist would transfer the material to a charging hopper.
The disposal of halogen-bearing pesticides and solvents presents complica-
tions of no small matter. These materials release the corresponding acid
vapors when burned, thus precluding the use of simple pits or furnaces.
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The incinerator stack gas must be scrubbed with water or an alkaline
medium, and the scrubber effluent should be sent to a wastewater treat-
ment plant employing secondary treatment. If the wastes contain sodium
salts, a simple packed tower will probably be inadequate and a high-energy
Venturi type scrubber may be required. Under any circumstances, appro-
priate governmental approval must be obtained for release of gases to the
atmosphere or discharge of liquids to municipal sewers or to other water-
ways. Figure B-5 shows schematically a system (now in use) which was
worked out jointly by Bigelow Liptak and the Dow Chemical Company for the
disposal of chlorinated wastes.
Operating Considerations. In addition to mechanical safety features for
the physical plant, other considerations require attention to assure the
safety of the operator, the public and environment. These may range from
container and ash disposal to material properties such as thermal stability,
shock sensitivity, flash point, flammable limits, auto ignition and toxicity.
Operating records, such as temperature charts, wind direction and velocity
data, character and quantity of material handled, etc., should be retained.
Composite samples of ash and scrubber water should be collected and ana-
lyzed from time to time and the stack gas should be monitored for composi-
tion and particulate content.
High temperature operation will require frequent inspection and routine
maintenance. Accurate operating and maintenance records are obviously
important. Burners firing liquid waste and heavy fuel are subject to
deposits in the burner nozzle and may require cleaning daily. Shutdown
and safety systems should be tested at scheduled intervals in accordance
with written procedures.
Contract Services
Private processors of industrial waste frequently operate in communities
of moderate to large size for the convenience of plants not large enough
to warrant in-plant disposal service. Municipal collection agencies also
exist, and depending upon the nature of the waste, as well as upon rela-
tive economics, a choice can be made between municipal or a private service.
However, it must be emphasized that getting some organization to "cart the
waste away" does not always solve the problem. From a legal standpoint,
should an adverse event occur as a consequence of improper handling or dis-
posal, the company as well as the contractor can be liable. If there are
details or handling precautions that a prudent knowledgeable industrialist
would consider, it is incumbent upon him to communicate these to the con-
tractor; or the contractor's inadvertent mishandling may come back to
haunt the company.
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Information on the availability of these facilities in your area can be
obtained from the U. S. Government Environmental Protection Agency.
Addresses and telephone numbers of Regional EPA offices are listed below.
Region Address
I Environmental Protection Agency
John F. Kennedy Federal Building, Room 2304
Boston, Massachusetts 02203
617-223-7210
(Maine, New Hampshire, Vermont, Massachusetts,
Rhode Island, Connecticut)
II Environmental Protection Agency
26 Federal Plaza
New York, New York 10017
212-264-8958
(New York, New Jersey, Puerto Rico, Virgin Islands)
III Environmental Protection Agency
6th and Walnut
Philadelphia, Pennsylvania 19106
215-597-9875
(Pennsylvania, West Virginia, Maryland, Delaware,
District of Columbia, Virginia)
IV Environmental Protection Agency
Suite 300
1421 Peachtree Street, N.E.
Atlanta, Georgia 30309
404-526-3454
(North Carolina, South Carolina, Kentucky,
Tennessee, Georgia, Alabama, Mississippi,
Florida)
V Environmental Protection Agency
1 North Wacker Drive
Chicago, Illinois 60606
312-353-5756
(Michigan, Wisconsin, Minnesota, Illinois,
Indiana, Ohio)
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Region
VI
VII
VIII
IX
Chemical Methods
Address
Environmental Protection Agency
1600 Patterson Street
Suite 1100
Dallas, Texas 75201
214-749-1461
(Texas, Oklahoma, Arkansas, Louisiana,
New Mexico)
Environmental Protection Agency
1735 Baltimore Avenue
Kansas City, Missouri 64108
816-374-3036
(Kansas, Nebraska, Iowa, Missouri)
Environmental Protection Agency
1860 Lincoln Street
Denver, Colorado 80203
303-837-3849
(Colorado, Montana, Wyoming, Utah,
North Dakota, South Dakota)
Environmental Protection Agency
100 California Street
San Francisco, California 94111
415-556-0218
(California, Nevada, Arizona, Hawaii)
Environmental Protection Agency
1200 6th Avenue
Seattle, Washington 98101
206-442-1296
(Washington, Oregon, Idaho, Alaska)
Chemical means of waste treatment prior to the ultimate disposal of par-
ticulate waste are varied. Some convenient categories of treatment appli-
cable to pesticide wastes are:
Ion Removal by Chemical Precipitation. Dissolved substances that combine
to form a compound having low solubility may be readily removed by filtra-
tion or settling of the precipitate.
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Ion Exchange. Toxic, deleterious, or valuable dissolved substances may be
concentrated for ultimate disposal or reuse by removal from solution onto
an ion exchange resin.
Coagulation. Coagulation is a process in which chemicals are added to an
aqueous system for the purpose of creating rapid-settling aggregates out
of finely divided, dispersed matter with slow or negligible settling ve-
locities. The specific coagulant and technology used vary with the waste,
but common coagulates include lime, alum, ferric chloride, ferrous sulfate,
and the newer synthetic organic coagulants known as cationic polyelectro-
lytes. As an example, trace amounts of DDT have been removed from water
supplies by this method.
Oxidation. Chemicals that react with organic impurities and have found
application in treatment of aqueous wastes include: hydrogen peroxide,
potassium permanganate, ozone, oxygen, chlorine, and chlorine dioxide.
Alkaline or Acid Destruction. Certain chemicals may be decomposed by being
subjected to acidic or alkaline conditions; e.g., some chlorinated hydro-
carbons are decomposed under acidic conditions, others under alkaline con-
ditions; trace amounts of phosphate insecticides have been destroyed by
alkaline hydrolysis.
Adsorption. To be precise, adsorption is a physical-chemical phenomenon,
but its potentially wide application in water and waste treatment warrants
its inclusion. By definition, adsorption is the concentration and collec-
tion of contaminants at the surface of a solid. The most efficient adsor-
bent is activated carbon, but coal has been used. Adsorption can take
place in fixed beds under pressure provided with regeneration facilities.
An efficient adsorption process has been installed by a herbicide manu-
facturer producing 2,4-D acid, MCPA acid, 2,4-DB acid and their esters.
Phenolics were removed from a waste stream by passing through two fixed
bed adsorbers containing granular activated carbon. Carbon is regenerated
in a furnace. The treated effluent from this system consistently contains
less than 1.0 mg/liter phenolics and is compatible with a municipal sewage
system.
Municipal Treatment
When a plant has access or connection to a sanitary or industrial sewer,
it may be possible to contract for treatment and disposal with a munici-
pality. In such a case, a company can devote all its efforts to produc-
tion and allow a municipality to handle the treatment and disposal. In
no event, however, should the plant consider itself relieved of respon-
sibility by such an arrangement. It should be recognized that this would
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be another form of contract services which has been discussed previously.
Specifications contained in local sewer ordinances or in specific con-
tractual arrangements must be adhered to. Where the concentration of
specific substances exceeds the allowable, pretreatment measures will
have to be taken within the plant property. Reduction in strength of
waste may be achieved by:
• Process changes.
• Equipment modifications.
• Segregation of strength waste.
• Equalization and proportionation of waste.
• By-product recovery.
• pH control through neutralization.
• Collection of floating or settleable matter by passage through:
manually cleaned baffled traps, detention and settling; tanks with endless
chain scrapers; manual or mechanical screens; filters; and other "packaged
plants" or facilities available from engineered equipment manufacturers
in the liquid conditioning field.
The cost of this type of waste treatment and disposal is dependent on the
municipality and the characteristics of the waste. In many cases, it may
be the most economical means of treatment because of economics of size,
lower cost, labor and the benefits of low municipal bond rates of interest.
It is most important that the specifications for the waste discharged into
the municipal system not be exceeded because of the danger of bad public
relations.
Deep Well Injection
This method is usefully applied in those areas where the subsurface geology
is favorable. Basically, it requires the injection of clarified fluids
into formations containing noncommercial and compatible saline waters.
The wells and surface equipment are designed for the particular problem
and the installation should be made, or at least supervised, by firms or
individuals known to be technically experienced and competent in the field.
The plant management, prior to approaching the regulatory agency, should
have had a feasibility study performed. The report should include a
description of the subsurface geology, an estimate of the expected hydro-
logic performance during injection, a definition of the chemical and
physical properties of the waste in question, a detailed description of
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the well to be installed and a summary of the surface equipment to be used.
The feasibility report should also contain cost estimates, including the
costs of operation.
Depths of industrial disposal wells have varied from 1,000 ft to over
12,000 ft. It generally is not considered good practice to install a
well less than 2,000 ft deep; the most frequent depth is from 3,000 to
6,000 ft. Volumes injected vary from 10 gpm to over 1,000 gpm. In some
parts of the United States, capacities may approach or exceed 5,000 gpm.
Volumes injected most frequently range from 30 gpm to 200 gpm.
Particular care must be exercised in designing and operating the system so
that natural resources can be properly protected from damage or contamina-
tion. Once the system is placed in service it should be operated and con-
trolled with the care and attention to detail required by other industrial
installations and not relegated to some unsupervised or poorly regulated
status that will result in operating failures.
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DISPOSAL OF SPECIFIC CLASSES OF PESTICIDES
The applicability of a given waste treatment technique to a specific
waste stream is determined by a number of factors, the most important
of which is the pesticidal chemical involved. The following section
contains a brief discussion of the applicability of specific treatment
methods to individual families of pesticides. Representative classes
have been selected for discussion. The omission of certain pesticide
families from this discussion, therefore, should not be interpreted as
indicating that these pesticides present no waste disposal problem, or
that the treatment techniques discussed would not be applicable to their
treatment.
Chlorinated Hydrocarbons
Waste materials from plants manufacturing or formulating chlorinated
hydrocarbon pesticides may be in several forms:
• Solids (technical materials, wettable powders, dust concentrates,
and granules).
• Liquids (technical materials, oil solutions, and emulsible
concentrates).
• Gaseous (true vapors, or aerosols).
It is suggested that the disposal systems described in the preceding
sections of this manual be reviewed and considered for applicability in
a particular chlorinated hydrocarbon pesticide plant situation.
Waste materials must not be flushed down sanitary sewers. Most of the
chlorinated hydrocarbon pesticides pass through normal sewage treatment
plants unchanged and may enter public water supplies.
Incineration. Incineration is undoubtedly the most positive system for
the disposal of chlorinated hydrocarbon pesticides in a solid, liquid,
or gaseous state. A variety of systems, all of which are somewhat ex-
pensive to construct, maintain, and operate, have been developed for
incineration of wastes. Most commonly, the resulting hydrogen chloride
gas is reacted with an alkali to form a salt. Under certain circumstances,
however, it may be desirable to recover the hydrogen chloride as an
aqueous solution for other uses.Ziz/
Biological Treatment. A search of the literature has revealed that little
published work on this technique is available at this time. Discussions
with several of the major manufacturers of chlorinated hydrocarbon pesticide
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indicate that research is now in progress to develop commercial biological
treatment techniques. They agree that the technique has promise for a
specific product, but has little likelihood of success on mixtures such
as the wastes from a formulating plant handling a variety of pesticides."
Organic Phosphates
The physiological action of toxic organic phosphates is due to their
ability to combine rapidly and in very small concentrations with cholin-
esterase in the central nervous system. This anticholinesterase material
permits the acetylcholine to continue its stimulating effects which
immediately cause an interference in the muscular system and possible
complete paralysis is the result. Acute poisoning from these toxic
organic phosphate compounds can result from absorption of the material
through the skin, from inhalation of its vapor or dust, or from swallowing
the material. Prompt first-aid and medical treatment is essential in all
cases of organophosphorus poisoning.
The handling and disposal of waste organic phosphates is a specialized
field. These and other related waste materials may be safely disposed
of by proper selection and utilization of a combination of the normal
waste disposal methods of hydrolysis and filtration, incineration,
burying, deep sea dumping, and deep well disposal.
The best overall prescription for waste disposal is the philosophy and
simple economics of waste control—the smaller the quantities to be
disposed of, the easier and less expensive the solution to the problem.
Hydrolysis and Filtration. Many organic phosphate compounds can be
hydrolyzed and, in general, the rate of hydrolysis is dependent upon the
pH and temperature of the aqueous solution. Liquid wastes containing
toxic organic phosphorus compounds are normally collected, adjusted to
the desired pH by the addition of an alkaline agent, then passed through
a hot water heater. The neutralized waste effluent should then be
collected in a large surge tank, analyzed for toxicants, and the de-
toxified waste pumped into the wastewater of the sanitary sewage disposal
system. This type of detoxified waste material should remain as a separate
entity and not be passed through the sanitary waste system if any adverse
reaction will occur with the dissolved chemicals and the clarifier-
digester of the typical sewage disposal system. Fonaulators should check
with their suppliers as to whether any problems may be involved.
An effective control practice is to maintain a recording pH meter and
a flowmeter on the waste effluent line just before the effluent leaves
the control of the industrial facility. Minute particles of suspended
solids in the waste effluent can be removed by passing the neutralized
waste through a filter.
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Incineration. This procedure can be safely used to destroy organic
phosphate waste materials. Sufficient heat (1800°F) must be generated
during the incineration to destroy the pesticide, as well as the con-
tainer, diluents, and solvents. Proper safety precautions must be
taken as to distance from habitation, trees, and other living things.
Burying. In some instances, burying organic phosphate waste material
can be considered a satisfactory procedure for disposing of contaminated
waste but there are so many external factors to be considered that this
procedure should only be used as a last resort. Location of the pit,
types of soil, land drainage, predominant wind direction, water sources,
and possible future use of the land are among the many factors that must
be considered. In any event, detailed records of the actual location of
the "burial ground" must be maintained (see "Burial," p. 110).
Deep Well Disposal. Deep well disposal can be applied to organic phos-
phate wastes.
Spills and Broken Containers. When a leaking, sifting, or damaged con-
tainer is discovered, isolate the area and use the following precautions:
• Safety equipment for personnel. Equip the man who will process
package with a Pulmosan C-241 respirator with type GMP cartridge or equiva-
lent, heavy gauntlet neoprene or rubber gloves, and washable clothing,
also rubber boots if necessary. The man should not carry cigarettes,
chewing gum, etc., in the pockets of his clothes. Tell him that he will
be safe if he avoids all skin contact and washes well after the operation.
All precautionary statements on the label should be carefully read and
observed.
• Small bag removal. Standing to windward, the operator should
remove undamaged bags from carton, wipe bags with barely damp cloth (to
be burned later) moistened with a strong soda ash solution and transfer
to new carton. Broken bags and original carton are to be held for re-
working or disposal in a sealed metal drum, properly labeled and with a
poison label.
• Fiber drums. Remove to suitable hood with exhaust ventila-
tion or to remote open area. Standing to windward, slowly transfer
powder, creating a minimum of dust, to new drum and re-label. Burn old
drum (avoid fumes) or bury i'f burning is not permitted.
• Metal containers. Alter position of container to place leak
flow on top. (Avoid skin contactI) Remove to suitable hood with exhaust
ventilation or to remote open area, (a) If feasible, transfer contents
to new drum via bung fittings, (b) If existing bungs cannot be used,
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equip a new drum vlth a large funnel. Position leaking drum over funnel
so that it leaks into it.
Spills can be decontaminated by the following procedure: Fill old drum
with caustic soda solution; discharge on ground in burial area and cover
with dirt. Rinse drum and decontaminate or discard in a safe manner.
(See NACA "Manual for Decontamination and Disposal of Empty Pesticide
Containers.11!/)
• Spilled dusts and powders. Cover dust or powder spills with
double its volume of damp (n&t wet) hydrated lime, clay, or sawdust.
Gather carefully with old broom. Sweep into a disposable container.
Burn or bury broom and container.
• Liquid spills. Cover liquid spills with an inert absorptive
substance such as hydrated lime, sawdust, clay, or fuller's earth. After
the liquid has been absorbed into the drying material, carefully gather
with old broom. Sweep into disposable container. Burn or bury container
and broom.
• Follow-up treatment for area. Revisit spill area and either,
(a) sprinkle with hydrated lime or soda ash (1 handful per square foot),
dampen slightly with hose or sprinkling can, rope off ares, allow to
remain overnight, flush away in morning. If yellow coloration appears,
repeat until color does not appear, or (b) cover the contaminated sur-
face with undiluted household bleach, scrub the area with long-handle
scrub brushes for at least 25 min. (Avoid breathing vapors from this
process.) Take up the scrubbing liquid with absorbent clay or similar
material. Repeat the whole process, allow treated area to dry. Dispose
of the contaminated absorbent in a safe manner.
• Follow-up by personnel. It is imperative to take a bath
after these operations. Launder clothes before reuse. Read label care-
fully for first-aid instructions.
General Considerations. Any reaction muds or waste process materials
which cannot be reused should be removed from manufacturing or storage
vessels and transferred to drums which are removed for incineration or
burial in an approved, supervised area. •
In the manufacturing area for pesticide products, drains should be
eliminated to avoid any washing of spills to the main plant sewers.
Material should be picked up manually or by vacuum and either returned
to process area for rework or transferred to the dump where it is
incinerated or buried.
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Dust collecting facilities should be provided on all major process
equipment, and, in addition, high velocity suction points should be
provided at all critical areas on the packaging lines.
Carbamate Pesticides
The major carbamate pesticides in use today include the insecticide
carbaryl (SEVIN®) and the herbicides IPC and chloro-IPC (isopropyl-N-
phenylcarbamate and chloroisopropyl-N-phenylcarbamate).
Characteristics of Carbaryl. Principal characteristics of carbaryl of
interest in waste disposal are the following:
• Low toxicity to warm-blooded animals, fish, fowl, wildlife.
• Decomposes relatively quickly in soil.
• Under alkaline conditions it breaks down fairly rapidly.
• It is insoluble in water (less than 0.1%) and only moderately
soluble in organic liquids (toluene—5%, acetone—207., deodorized
kerosene—57»).
• Carbaryl will burn fairly readily. (CAUTION: Carbaryl
dusts are explosive!)
• Dilute suspensions of carbaryl are amenable to treatment by
biological disposal systems. Standard tests have shown that carbaryl
exerts a 5-day biochemical oxygen demand (BODc) of about 0.2 Ib of oxygen
per pound of carbaryl. This value increases to about 0.6 Ib per pound
after acclimation of the seed bacteria. No gross bacterial toxicity was
noted up to a concentration of 100 mg/liter. Suspensions containing up to
100 mg/liter per liter of carbaryl which were fed to laboratory activated
sludge units were oxidized quite efficiently after acclimation of the
bacteria. No adverse effects on the biological populations were noted.
Similar results were obtained in a simulated sewage oxidation pond
although carbaryl rates were generally somewhat lower.
The carbamates listed are subject to alkali hydrolysis and can be de-
composed by the addition of strong alkali. Adequate mixing with the
alkali is necessary. A stirred vessel should be used. Reaction products
from this step should then be routed to the sewage treatment facility.
For disposing of small volumes of carbaryl suspended in water, caustic
treatment in a settling tank may be sufficient. For each 5 Ib of carbaryl
carried into the tank, addition of 2 Ib of flake caustic will provide a
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50% excess of the minimum required to react with the carbaryl. Reaction
time will vary depending upon dilution and temperature but 24-hr treatment
time should insure completeness of reaction.
Where continuous treatment of wastes with this technique is necessary,
a pair of settling tanks would be required in order to permit holding
of wastes for the needed treating time period. Size of the tank, of
course, would be dictated by the volume of water expected to accumulate
in each 24-hr period.
Where water used in flushing floors or equipment needs to be disposed
of only occasionally, it may be simplest to drain this to an outside
holding pit for caustic treatment as described above before it is per-
mitted to drain from the plant area.
Solid wastes, which cannot be easily treated by reaction in water with
caustic or biologically oxidized, should be buried through landfill
techniques. Lime should be dumped or mixed with the carbaryl waste in
ratio of one part lime to five parts of waste.
The landfill should be located above grade and so situated that leaching
of buried wastes and their being carried away by surface runoff water
is not possible.
Where fires in open fields are permissible, this allows convenient dis-
posal of empty bags from carbaryl technical. Under some combustion
conditions, carbaryl burning can produce methyl isocyanate which is a
toxic material.
Exposure to smoke and gases from the burning bags should be avoided.
Normally designed incinerators will permit achieving of higher tempera-
tures (1800°F) at which carbaryl is more completely oxidized to harmless
products.
Air pollution aspects need to be kept in mind. In most areas, particularly
those more heavily populated, open burning is forbidden by law.
Where burning or controlled combustion cannot be safely accomplished and
where air pollution is a factor, then burial of empty bags as described
above is the preferred disposal technique.
IPC and Chloro-IPC Treatment. The chemical treatment for IPC and CIPC
(isopropyl-N-phenylcarbamate and chloro-isopropyl-N-phenylcarbamate)
wastes as well as suggestions for incineration and burial are the same
as for carbaryl.
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Dithlocarbamate Pesticides
Formulators handling dithiocarbamates should give serious consideration
to vaste handling and disposal. In many areas, local governments have
specified the procedures that must be used for disposal of liquid and
solid wastes. In these areas the prescribed method is then the minimum
level of care that must be taken.
We believe the following control on wastes should be considered the mini-
mum in cases where there is no municipal control or where the specified
control is less than that now outlined.
Handling of Solids. Empty fiber containers, drum liners, paper bags,
dust bags, or other combustible refuse contaminated with dithiocarbamate
should be collected in a metal container, provided with a lid, and then
sent to a municipal incinerator or burned in a private incinerator under
strict control to meet all local ordinances. (Sulfur dioxide is one of
the products of dithiocarbamate combustion.)
Metal or other nonburaable containers that are to be discarded due to
damage or because salvage would be too costly should be disposed of in
a sanitary landfill operation, or if sold to scrap dealers, should be
steam cleaned and washed before leaving the premises.
Metal containers that are to be reused can be safely used for nonfood
products if they are reconditioned by a "Drum Reconditioner" who pro-
cesses them by the standard treatment at drum reconditioning plants.
(See NACA "Manual for Decontamination and Disposal of Empty Pesticide
Containers1^/ for full recommendations concerning drum decontamination
and reconditioning.)
Solid dithiocarbamate recovered from dust collectors, vacuum cleaners,
floor-sweepings, equipment cleanout, etc., should be packaged in steel
drums and then disposed of in a sanitary landfill where a trench is
made, the drums dropped in and the trench backfilled with earth. These
operations are usually under municipal control and o.re in locations where
ground percolation will not contaminate the local water supply.
Handling of Liquids. The sewer lines in buildings handling dithiocar-
bamates should run into a settling basin where solids can settle out
and be removed for disposal as outlined above. Soluble dithiocarbamates
can be precipitated by the addition of zinc salts in slight excess if
it becomes necessary to remove dithiocarbamates to satisfy the require-
ments of a sewage treatment plant. The clear effluent can then be treated
in a municipal sewage disposal plant if the local authorities will accept
it. The dilution accomplished by blending this waste into the total waste
stream going to the sewage disposal plant dilutes it to an acceptable level.
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Botanicals
Botanicals such as rotenone, pyrethrum, sabadilla, and ryania, as well
as synergists useful with botanicals, must be considered as having
potential for causing injury to fish, if allowed to enter streams, lakes,
or groundwaters. The many formulations of botanicals include dusts,
oil solutions, emulsifiable concentrates, and liquids in pressurized
containers (aerosols).
Again, it must be recognized that the first step to safe disposal of
these materials is to reduce to an absolute minimum the amount of such
wastes to be disposed of by utilizing the best manufacturing, formulating,
and housekeeping methods.
Wastes of a botanical nature can then be handled as follows:
Burial. Burial of solid botanical formulations can be accomplished in
those locations where the burial site is free from groundwater movement.
This is particularly important in view of the fish toxicity of rotenone
and other botanicals. Local authorities should be consulted in making
a choice of burial site.
Liquid botanical wastes can be buried if first absorbed on a suitable
diluent. Diatomaceous earth, fuller's earth, and other highly absorp-
tive diluents are examples of materials upon which liquid wastes can be
absorbed before burial.
Incineration or Burning. Both liquid and solid wastes containing botani-
cals can be safely destroyed by incineration in a suitable unit. Open
burning of botanicals is not recommended, largely because of the poor
combustion occurring near the soil surface. Thus, seemingly destroyed
material can remain behind to cause subsequent pollution due to movement
by wind or rain. Also, many of the solid wastes consist of the botanical
on a noncombustible carrier and open burning cannot be depended upon to
heat the mass to the decomposition point.
Liquid formulations of botanicals are even more amenable to incineration
in a well-designed burner due to the usual presence of solvents in the
formulation and these help support combustion.
Municipal Sewage Treatment. A small, regulated flow of botanical wastes
can be accommodated by municipal sewage treatment plants using secondary
treatment consisting of either trickling filters or activated sludge.
Permission must first be obtained from local authorities to permit this
approach and a means of controlling the amount to be discharged must be
incorporated in the discharge system.
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Phenoxy Acids, Salts, and Esters
The manufacture of phenoxy herbicides and their formulations presents
potential vater pollution problems.
Formulation of phenoxy herbicides starting with the active acids or
esters and addition of amines and water, or oils and emulsifiers,
respectively, generate very little waste as such, if due consideration
is given to design, operation and control of inadvertent spills by use
of dikes and collecting pits. Good initial drainage and rinsing with
diluent used in the formulation so that the rinse can be used in future
runs, along with efficient final washing and rinsing would result in
minimal volume of low concentration of wastes to dispose of by methods
to be described.
2,4-D and 2,4,5-T. These phenoxy herbicides are not widely used in the
free acid or sodium salt form because of low solubility and limited
herbicidal activity. User perference and need are usually better met
through enhanced herbicidal activity, which results when the parent
compound is altered to the ester, an oil-soluble form, or to the amine
salt, a water-soluble form. The most common forms of 2,4-D and 2,4,5-T
are shown in Table B-2.
TABLE B-2
COMMON ESTER AND AMINE FORMS OF PHENOXY HERBICIDES §/
2,4-D 2,4,5-T
(2,4-Dichlorophenoxyacetic Acid) (2,4,5-Trichlorophenoxyacetic Acid)
Esters Amines Esters Amines
Isopropyl Ethanol amines Glycol ethers Triethyl
Butyl Mixed alkanol
amines
Iso-octyl Dimethyl amine
Glucol ethers Triethyl amine
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Other Phenoxy Herbicides. Other phenoxy herbicides include MCPA (2-
methyl-4-chlorophenoxyacetic acid), sesone, silvex, 2,4-DB [4-(2,4-
dichlorophenoxy) butyric acidj, and erbon.
The amine salt formulations are generally 4 Ib acid equivalent per gallon
of the amine salt dissolved in water. Small amounts of sequestering
agent are added to the formulation to prevent precipitation of calcium
and magnesium salts in the sprayer. Formulations intended for the home
gardener usually contain lesser amounts of active ingredient per gallon
and include an alcohol, such as isopropanol, as an antifreeze.
The ester formulations are made by dissolving the ester in a suitable
solvent and adding emulsifier. The emulsifier is frequently a minor
part of the total formulation, usually less than 57,, and usually consists
of a blend of non-ionic and anionic emulsifiers. Perhaps the most
troublesome portions of the formulation from a waste disposal standpoint
are the aromatic solvents and fuel oil or kerosene used as diluents.
Incineration. At least 1800°F and 1 sec detention time when using a
straight combustion process must be provided. Catalytic combustion can
lower this temperature to levels of about 900°F.
Chemical Treatment. Chlorination can be accomplished by adding sodium
hypochlorite solution or gaseous chlorine to the liquid waste in a suitable
reactor until a residual chlorine level is achieved. Temperatures some-
what above 85°F, at pH 3, and retention times of at least 10 min are
required to render many of these materials nonherbicidal.
Strong solutions of acid, amine, or other salts of 2,4-D and 2,4,5-T
can be precipitated with calcium or magnesium salts to reduce the
quantity of herbicide in a gross manner. This technique is not useful
with esters.
Biological Treatment. 2-' Proper biological treatment is highly tempera-
ture-dependent and requires temperatures about 75°F for effective operation
and removal of the active herbicide. Biological treatment would include
trickling filters, activated sludg , and sewage lagoons.
Assuming a concerted effort on the part of-all employees in a plant to
keep herbicide wastes out of the water, then the small amounts that do
occur in an unavoidable fashion can be treated adequately by biological
means. Such compounds include:
2,4-D acid
2,4,5-T acid
MPC acid
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isopropyl ester 2,4-D
propylene glycol butyl ether ester 2,4-D
propylene glycol butyl ether ester 2,4,5-T
butyl ester 2,4-D
alkanol amine salt 2,4-D
dimethyl amine salt 2,4-D
Pesticide plant operators faced with the necessity of supplying treat-
ment methods for contaminated wastewater should not overlook the favorable
economics possible through use of sewage stabilization ponds or lagoons.
In warmer climates, this can be an effective method of disposal with
throughputs of 20 to 40 Ib biochemical oxygen demand (BOD) per acre per
day. Many states already provide information on design and construction
of such ponds, as does the U. S. Public Health Service.—/
Biological treatment of wastes where space is not available for a pond or
where soil conditions preclude its use can be accomplished with package
treatment units embodying activated sludge units or the new vertical trick-
ling filter units containing biological oxidation media.—'
Deep Well Disposal. H Deep well disposal consists of pumping liquid wastes
into a deep well drilled to a natural subterranean stratum capable of ac-
cepting the volume of such liquids to be pumped. Identification of such
strata must consider the possibility of leakage to potable water sources
and surface streams. However, where such discrete strata exist, deep well
disposal can be considered where permitted by local regulatory agencies.
Inorganic Pesticides
Arsenicals. Two methods for disposal of arsenicals are generally applicable.
• Burial. Since most of these compounds are quite insoluble,
disposal of solid residues by burial in an approved location is a recom-
mended practice.
• Municipal system or receiving water. The permissible level of
0.05 rag/liter of arsenic (as As) established for public water supplies is
the governing f actor. H' Waters from the disposal area must be monitored
to make sure this limit is not exceeded.
Borates . Borates can be disposed of by burning under controlled conditions.
Chlorates. Chlorates are best disposed of by careful burning in small
amounts so as to avoid any great hazard from the oxidizing power of these
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materials. Extreme care should be taken to prevent chlorate wastes from
being mixed with any organic matter, as explosive conditions can result.
The Environmental Protection Agency has made the following recommendations
for the disposal of small quantities of inorganics.—'
"... inorganic pesticides should be disposed of according
to the following rank order of procedures:
"(1) Chemically deactivate the pesticides by conversion to
nonhazardous compounds, and recover the heavy metal resources.
It is intended that such methods as are appropriate will be des-
cribed and catalogued according to their applicability to the
different groups of pesticides.
"(2) If chemical deactivation facilities are not available,
such pesticides should be encapsulated and buried in a spe-
cially designated landfill. Records sufficient to permit
location for retrieval should be maintained.
"(3) If none of the above options is available, place in
suitable containers (if necessary) and provide temporary
storage until such time as adequate disposal facilities
or procedures are available."
Triazine Herbicides
The most important triazine herbicides are:
simazine (2-chloro-4,6-bis (ethylamino)-s-triazine),
propazine (2-chloro-4,6-bis(isopropylamino)-s-triazine),
atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine),
prometone (2,4-bis(isopropylatnino)-6-methoxy-s-triazone),
prometryn (2,4-bis isopropylamino-6-methylthio-s-triazine) ,
ametryn (2-ethylamino-4-isopropylamino-6-methylthio-s-triazine), and
terbutryn (2-tert butylamino-4-ethylamino-6-methyl-thio-s-triazine) .
Table B-3 shows some of the important properties of these compounds.
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TABLE B-3
PROPERTIES OF TRIAZINE HERBICIDES
c/
Stability-
Molecular
Herbicide Weight
Simazine
Propazine
Atrazine
Prometone
Prometryn
Ametryn
Terbutryn
201.6
229.7
215.7
225.3
241.4
227.3
241.4
Melting
PointS/
223-225
212-214
173-175
91-92
118-120
84-86
104-105
Solubility
in Wateifi/ H2°
5
8.6
33
750
48
185
58
>1800
>1800
>1800
>1800
>1800
>1800
>1800
0.1N
HC1
5.1
5.6
5.4
24.1
22.2
22.9
22.0
0.1N
NaOH
2.2
3.6
2.9
141
1200
1440
>1800
Toxicity
Rate!/
5000
>5000
4050
2980
3750
1405
2980
§_/ Noncorrected °C.
b/ ppm at 20-23°C.
£/ Half-life time, in days, at 25°C.
d/ Oral LD50 in mg/kg.
Since these compounds and their decomposition products or metabolites
are of relatively low mammalian toxicity, the main concern in disposal
of vastes is to ensure that the herbicidal properties are destroyed or
diluted to ineffective levels before release to the environment. The
decomposition products of these compounds do not have herbicidal activity.
Incineration. Incineration in a properly designed municipal or industrial
incinerator is the most effective way of ensuring destruction of the
herbicide. Gases from the incinerator should be scrubbed to avoid releasing
acids to the atmosphere. The effluent from the scrubber in form of gases
to the atmosphere and liquid to the sewer should be monitored to ensure
that they are free of herbicide. Ash from the incinerator should be
buried in a sanitary landfill.
Incineration lends itself to the safe disposal of all types of formula-
tions and packaging materials, except metal cans and drums, as well as
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the herbicidal compound and its by-products. The contents of metal con-
tainers can be incinerated and the containers can be disposed of separately.
(See NACA "Manual for Decontamination and Disposal of Empty Pesticide Con-
tainers."!/)
Open air burning should be avoided.
Chemical Treatment. The properties tabulated in Table B-3 indicate the
susceptibility of the triazines to acid and alkaline hydrolysis. This
method is an effective way of treating aqueous effluent from the reaction
and formulation processes. The rate of hydrolysis is dependent upon the
pH and temperature of the aqueous solution. After adjusting to pH of 1,
the solution should be passed through a hot water heater and discharged
into a holding pond. The concentration of herbicide in the holding pond
should be monitored to determine when it is safe to discharge the solution
to the sewer.
This procedure does not lend itself to disposal of large quantities of
waste chemicals, formulations, or packaging.
Deep Well Disposal. Solutions and slurries of triazine herbicides can be
pumped into properly located deep wells. To be effective, a deep well
must provide access to a rock-bound stratum with enough capacity to hold
the volume of liquid to be pumped. There must be no possibility of leakage
to water sources and surface streams.
This method of disposal is less desirable because the decomposition of
the herbicide is not accomplished before release to the environment and
it is difficult to determine the potential of a given well to leak.
This method also does not provide for disposal of empty containers.
Burial. Disposal by burial of untreated wastes should be considered
only as a last resort. If no other alternative is available, the burial
must be done only in an area approved by local authorities that is free
of groundwater movement. Liquids should be absorbed on diluents such
as attapulgite, montmorillonite or diatomaceous clays before burial.
Contract Services. If disposal is accomplished through a company or
municipality that provides this service, the contractor should be ad-
vised of the proper means of disposal and checked to ensure that proper
means are being used.
Substituted Ureas
The urea herbicides (monuron, diuron, etc.) possess a comparatively low
order of mammalian toxicity but will exert herbicidal activity at very
low concentrations. Care must be taken, therefore, to prevent atmospheric
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or aqueous effluent contamination. Solubility in water ranges from
5 to 4,000 ppm and activity is exhibited at the 1-ppm level.
Members of the urea class of compounds are used as both selective and
nonselective herbicides. Among the nonselective uses are prevention
of weed growth on plant sites. The selective uses include weed control
in crops such as cotton and soybeans. Formulations are available as
wettable powders, water dispersible liquids, pellets and granules.
Handling of Solids. Process vapors or ventilation air, carrying even
low concentrations of these herbicides, should be passed through scrubbers
or filters prior to discharge into the atmosphere. Contaminated equip-
ment or clothing should be cleaned in such a manner that herbicidal con-
tent of effluents will not be discharged into the plant aqueous effluent
at active, levels.
Use of a vacuum cleaner to pick up spills and dust is preferred to
flushing contaminated areas with water, since aqueous effluents require
additional treatment (see paragraph "Disposal of Liquid Wastes" below).
Solids recovered from dust collectors, settling tanks, filters, etc.,
should be reworked insofar as this is possible. Where rework is not
feasible, special disposal methods such as incineration or on-site burial
should be used.
Disposal of Liquid Wastes. Aqueous effluents containing urea herbicides
should be handled by extracting the soluble herbicide content by washing
the aqueous effluent with a suitable solvent prior to discharge.
Nonaqueous waste streams containing urea herbicides can be disposed of
by incineration or burial. Since many urea herbicides contain a halogen,
the combustive products from incineration will contain acid halides. A
gas scrubber may be required to remove the acid halides before discharge
to the atmosphere.
Chloroacetamide Herbicides
The major chloroacetamide herbicides in use today are:
Ramrod^, 2-chloro-N-isopropylacetanilide
Lasso®, 2-chloro-2', 6'-diethyl-N-methoxymethyl acetanilide
Machete®, 2-chloro-2', 6'-diethyl-N-butoxymethyl acetanilide, and
Randox®, 2-chloro-N, N-diallyl acetamide.
These products, used as solid and liquid forms, are relatively insoluble
in water. All decompose quite quickly in soil.
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Persons handling and using chloroacetamide herbicides should carefully
consider the disposal of wastes and containers. Of course all local
regulations should be rigorously followed.
Disposal of Liquids. Liquid wastes may be disposed of by burning at
temperatures exceeding 1800°F in a suitable incinerator. The products
of combustion are CO, C02, NO, N02, and HCl. These gases should be
passed through a water scrubber. The effluent from the latter, after
lime treatment, can be sewered or impended.
In cases of spills of liquid'chloroacetamide products, it may be prefer-
able to absorb the spilled material in clay, lime, sawdust, or other
absorptive material. These wastes should then be disposed of by the
methods suggested for treatment of solids.
Disposal of Solids. Empty containers made of paper, fiber or polymeric
materials, along with other contaminated, combustible wastes may be
burned in a suitable, controlled incinerator where local laws permit.
Open burning is not recommended. In areas where incineration is not
permitted, containers should be buried in carefully controlled la: dfill
operations.
Metal containers may be reconditioned for nonfood product use. Recon-
ditioning should be carried out in carefully controlled operations. The
methods outlined in NACA "Manual for Decontamination and Disposal of
Empty Pesticide Containers" are recommended.!-'
Solid chloroacetamide wastes (technicals, wettable powders, dusts and
granules) should be buried in controlled landfill operations which are
described in the "Burial" of this manual, p. 110.
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PESTICIDE CONTAINER DISPOSAL
The National Agricultural Chemicals Association has developed a quick,
easy procedure for draining and rinsing all single-trip containers.
This procedure, when conscientiously followed, significantly reduces
the hazard associated with empty pesticide containers.
Four simple steps are required:
Empty container into
spray tank. Then drain
in vertical position
for 30 seconds.
Rinse container
thoroughly, pour into
tank, and drain 30 sec.
Repeat three times.
Add enough fluid to
bring tank up to level
Add a measured amount
of rinse water (or
other dilutent) so
container is 1/4 to 1/5
full. For example, one
quart in a one-gallon
container.
Crush pesticide
container immediately
Sell as scrap for
recycling or bury.
Do not reuse.
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REFERENCES
1. Taras, M. J. (Editorial Chairman). Standard Methods for the Examination
of Water and Wastewater. Thirteenth Edition. American Public Health
Association, Washington, D.C. 1971.
2. Environmental Protection Agency. "Pesticides and Pesticide Containers:
Regulations for Acceptance and Recommended Procedures for Disposal
and Storage." Federal Register. 32(85):15236-15241. 1 May 1974.
3. Kennedy, M. V., B. J. Stojanovic, and F. L. Shuraan, Jr. "Chemical
and Thermal Methods for Disposal of Pesticides." Residue Reviews,
29:89-104. 1969.
4. Marks, D. R. (Technical Superintendent). "Operation and Problems
of a Chemical Waste Incinerator." Velsicol Chemical Corporation,
Memphis, Tennessee. Undated.
5. U.S. Patent 3,140,151, "Hydrogen Halide Recovery."
6. Sharp, D. H., and A. E. Lamden. "Treatment of Strongly Bactericidal
Trade Effluent by Activated Charcoal and Biological Means." Chemistry
and Industry, 39_: 1207-1216. 1955.
7. National Agricultural Chemicals Association. Manual for Decontamination
and Disposal of Empty Pesticide Containers. Washington, D.C. June
1965.
8. Kelly, J. A. "Commercial Herbicides—Present Methods of Formulation "
Ag and Food Chemistry, .3:254. 29 April 1953.
9. Winston, A. W., and P. M. Ritty. "What Happens to Phenoxy Herbicides
When Applied to a Watershed Area." Proceedings of the Northeastern
Weed Control Conference, JL5_:396-401. 15 January 1961.
10. Waste Stabilization Lagoons, Publication 872. U.S. Department of
Health, Education and Welfare. Superintendent of Documents,
Washington, D.C. August 1961.
11. Mills, R. E. "Development of Design Criteria for Biological Treat-
ment of 2,4-D Wastewater." Canadian Journal of Chemical Engineering.
3_7_(10):177-183. October 1959.
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12. Warner, D. L. "Deep Well Disposal of Industrial Wastes." Chemical
Engineering. 22(l):73-78. 4 January 1965.
13. Federal Water Pollution Control Administration. Water Quality
Criteria. Superintendent of Documents, Washington, D.C. 1 April
1968.
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APPENDIX C
CLASSIFICATION OF PESTICIDAL CHEMICALS
143
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The following classification of pesticidal chemicals was developed in a
recent study (Lawless, Edward W., et al., "Methods for Disposal of Spilled
and Unused Pesticides," (Draft), EPA Contract No. 68-01-0098, Project 15090
HGR, July 1973). Pesticides were categorized according to their potential
for detoxification.
Number of
Pesticide Classification Pesticides
Inorganic and metallo-organic pesticides
Mercury compounds 28
Arsenic compounds 17
Copper compounds 11
Other heavy metal compounds 6
Cyanides, phosphides, and related compounds 6
Other inorganic compounds 1J
79
Phosphorus-containing pesticides
Phosphates and phosphonates 19
Phosphorothioates and phosphonothioates 34
Phosphorodithioates and phosphonodithioates 27
Phosphorus-nitrogen compounds 8
Other phosphorus compounds _5
93
Nitrogen-containing pesticides
N-alkyl carbamates, aryl esters 22
Other n-alkyl carbamates and related compounds 7
N-aryl carbamates 6
Thiocarbamates 10
Bithiocarbamates 13
Anilides 13
Imides and hydrazides 9
Amides 6
Ureas and uracils 20
Triazines 14
Amines, heterocyclic (without sulfur) 18
Amines, heterocyclic (sulfur-containing) 12
Nitro compounds 26
Quaternary ammonium compounds 6
Other nitrogen-containing compounds 19
201
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Number of
Pesticide Classification Pesticides
Organochlorine, bromine or iodine pesticides
DDT 1
DDT-relatives 8
Chlorophenoxy compounds 12
Aldrin-toxaphene group 16
Aliphatic chlorinated hydrocarbons 15
Aliphatic brominated hydrocarbons 5
Dihaloaromatic compounds 10
Highly halogenated aromatic compounds 19
Other chlorinated compounds 4
90
Sulfur-containing pesticides
Sulfides, sulfoxides and sulfones 6
Sulfites and xanthates 4
Sulfonic acids and derivatives 5
Thiocyanates 4
Other sulfur-containing pesticides 4
23
Botanical and microbiological pesticides 19
Organic pesticides, not elsewhere classified
Carbon compounds 41
Anticoagulants 4
45
Total 550
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APPENDIX D
ESTIMATED COSTS FOR BEST TREATMENT TECHNOLOGIES
147
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Order-of-magnitude estimates were made for capital and operating costs for
best practicable and best available technologies. These estimates were
made for large formulation plants (40,000,000 Ib/year production) that
generate relatively large volumes of wastewater (25 gal/ton of product,
or 500,000 gal. of wastewater/year).
Conservative (optimistic), yet realistic cost data as well as readily
available, off-the-shelf items of equipment have been used so costs for
the minimum adequate system could be determined. Design parameters were
largely determined from actual plant or pilot plant data. (See Appendix
A, Case Study No. 7, p. 80.)
These same wastewater treatment systems, if built to the higher specifica-
tions required by many of the large producer formulators, could cost five
to 10 times our estimates. For comparison purposes, therefore, high side
estimates are shown in the last column of each estimate (10 times the con-
servative estimate). This high side represents the estimate of maximum
cost for a waste treatment facility constructed to more exacting specifi-
cations, i.e., those using specially designed equipment, and outside engi-
neering and construction. The costs of treatment are shown at the bottom
of the cost estimate.
148
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COST ESTIMATE NO. 1
BEST PRACTICABLE TECHNOLOGY - EVAPORATION
Basis for Calculations
Formulation rate - 40,000,000 Ib/year (formulated product)
Process wastewater rate - 25 gal/ton of formulated product
Waste treatment process - 250 day/year, 8 hr/day, 2,000 gal/day operation
Capital Costs
Pump
Surge tank (4,000-gal. gas tank)
Concrete evaporation pad (15 ft W x 30 ft L x 3 ft H)
Aeration pump system
Roof
Total
Yearly Operation Costs
Deemulsifier
Electricity
Labor (250 hr at $4/hr)
Fixed charges (25% of capital cost)
Total
Cost per gallon of wastewater
Cost per pound of product
Low High
$ 400
1,100
2,000
1,000
1.500
} 350
75
1,000
1.500
0.6
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COST ESTIMATE NO. 2
BEST AVAILABLE TECHNOLOGY - PRETREATMENT-FILTRATION-ADSORPTION
Basis for Calculations
Formulation rate - 40,000,000 Ib/year (formulated product)
Process wastewater rate - 25 gal/ton of formulated product
Waste treatment process - 250 day/year, 8 hr/day, 2,000 gal/day operation
Activated Carbon Criteria
120-min contact time
500 Ib of carbon/166,650 gal. of wastewater processed 2-gpm flow rate
(based on Case Study No. 7 data)
Capital Costs
Surge tank
Pump
Pretreatment tank
Filter and vacuum pump
Carbon column pump
Carbon column (10 ft x 2 ft diameter fabricated from
pipe)
Initial carbon charge
Installation
Piping
Electrical
Contingencies
Engineering
Total
Yearly Operating Costs
Carbon
Sludge removal
Deemulsifier and/or caustic
Diatomaceous earth
Labor (1,000 hr at $4/hr)
Utilities
Fixed charges (257» of capital cost)
Total
Cost per gallon of wastewater
Cost per pound of product
Low High
$1,100
1.
6,
1,
1.
1,
1.
1,
$16,
$1,
4,
4,
400 i
100
000
200
500
500
750
050
300
700
200
000
200
200
1 $167, 500
$167,500
$1,050
300
700
200
4,000
200
42,000
$10,650 $48,450
2.1c 9.7c
0.030
0.12c
150
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
RCPORT NO.
EPA-660/2-74-094
2.
. TITLE AND SUBTITLE
Pollution Control Technology for Pesticide
Formulators and Packagers
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
November 1974; Approval
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Thomas L. Ferguson
. PERFORMING ORG '\NIZATION NAME AND ADDRESS
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
10. PROGRAM ELEMENT NO.
1BB036
11. CONTRACT/GRANT NO.
Grant R-801577
17. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Southeast Environmental Research Laboratory
College Station Road
Athens, Georgia 30601
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
IB. SUPPLEMENTARY NOTES
Prepared in cooperation with the National Agricultural Chemical
Association's Committee on Agricultural Chemical Environmental Quality
16. ABSTRACT
The pesticide formulation and packaging industry transforms bulk
pesticidal chemicals into packaged, ready-to-use form for sale to the
consumer. Most pesticides are formulated in plants completely separate
from the site of active ingredient manufacture.
About 32,000 formulated products are federally registered to
approximately 3,400 companies for interstate sale. Most are apparently
formulated in the 200 to 300 large formulation plants through the
country.
Techniques used to dispose of process wastewater include evapora-
tion, landfill disposal, and contract disposal services, including
municipal systems. Current pretreatment and treatment techniques for
process wastewater discharge are generally considered inadequate to
meet increasingly stringent standards. The best practicable wastewater
treatment technology appears to be complete evaporation. The best
available treatment technology appears to be a pretreatment-filtration-
adsorption process under development.
Additional research is needed to: characterize the wastewater;
assess the air pollution potential due to pesticides; and demonstrate
the pretreatment-filtration-adsorption process.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Agricultural Chemicals, -Pesticides,
Water Pollution Sources, Air Pollu-
tion, -Wastewater Disposal, Evapora-
tion, Landfills, -Wastewater Treat-
ment, Adsorption, Chemical Degrada-
tion, -Solids Wastes, Incineration,
Landfills
tUDENTIFIERS/OPEN ENDED TERMS
'esticide formulation
industry, Pesticide
rormulator wastes,
Pesticide packager
wastes
c. cos AT I Field/Group
06/06
13. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report}
Unclassified
21. NO. OF PAGES
159
Release Unlimited
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
tPA form 222B-1 (9-73)
* U. S. GOVERNMENT PRINTING OFFICE: 1975-698-032/100 REGION 10
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