Environmental Protection Technology Series
Assessing the
Water Pollution Potential
of Manufactured Products
Office of Research and Monitoring
U.S. Environmental Protection Agency
Washington, D.C. 20460
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EPA REVIEW NOTICE
This report has been reviewed by the Environmental Protection Agency, 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.
ii
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ABSTRACT
A Catalog has been compiled of manufactured products which may, during
their normal use or disposal, result in water pollution. The Catalog is
in three sections, and the products are grouped in accordance with the
Standard Industrial Classification (SIC).
Section I summarizes the pollution potential of each listed product group.
Section II provides data on typical chemical compositions for each pro-
duct group and indicates the types of water-pollutional effects associated
with each chemical ingredient. Section III inverts Section II by providing
an alphabetical listing of chemicals and the SIC codes in which they occur.
Along with the Catalog, a simple model has been developed to estimate
rates of pollutant entry into the waterways via various routes, such as
direct discharge, runoff following rainfall, leaching from dumps, discharge
to the air and subsequent raindown. A guide including examples is provided
on how to use the Catalog and associated models to assess potential water
pollution problems arising from finished products in common use.
This report was submitted in fulfillment of Project 16080GNC and Contract
No. 68-01-0102 under the sponsorship of the Office of Research and
Monitoring, U. S. Environmental Protection Agency.
iii-
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CONTENTS
Section Page
I Conclusions 1
II Recommendations 2
til Introductidn 3
Need for the Catalog 3
Scope of the Catalog 4
Product Selection 4
Water Pollution Potential Evaluation 5
IV Catalog Organization 8
Section I - Summary 8
Section tl - Product Listing 12
Section ill - Chemical Ingredient Listing 12
V Model for Estimating Rates of Discharge of
Potential Pollutants 16
VI How to Use the Catalog 20
v
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FIGURES
No.
1
2
3
4
5
9
10
11
12
Page
10
13
14
17
22
24
26
27
30
31
32
vii
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TABLES
No.
Page
1
15
ix
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SECTION I
CONCLUSIONS
1. Many consumer products, during their normal uses, ultimately reach our
Nation's streams, lakes, estuaries, and groundwaters and may have a de-
leterious effect on water quality. These products, their chemical formu-
lations, and the potential types of associated water pollution, have been
cataloged.
2. Multiple pathways exist by which a given product may enter the water.
A conceptual framework for evaluating the importance of each of these
paths is necessary for the assessment of potential water pollution prob-
lems .
3. A simple mathematical model was developed to predict rates of discharge
of potential pollutants into the environment from the time of entry into
the use stream to the time of ultimate decay.
4. Important data are lacking with respect to product lifetime, amount
of product in use, water pollutional effects associated with the chemicals
used to formulate manufactured products, and indirect modes of entry of
products into the water from dumps, by runoff following rainfall, and
through leaching.
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SECTION II
RECOMMENDATIONS
1. The Catalog and the associated model should be expanded and computerized
to permit accessing of data in many different forms, as appropriate to par-
ticular problems, and to facilitate incorporation of new and updated
information.
2. The simple two-reservoir model for predicting rates of discharge of
potential pollutants should be extended to take into account multiple res-
ervoirs or pathways to the water and changing levels of production rates.
3. Research should be carried out to refine the data base. More precise
estimates of product lifetimes may be obtained from literature search and
personal interviews. Decay times for products disposed of in dumps or
volatilized and washed down by rain may require field experiments. Path-
ways by which products enter the water should be defined with reference to
the entire ecological cycle.
4. The utility of the Catalog and associated models should be tested on
a number of specific examples in order to provide a basis for future modi-
fication.
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SECTION III
INTRODUCTION
One 'of the characteristics of our advanced technology is the proliferation
of consumer products. New products for a multitude of uses are made
available to the public every year. Many of these materials, during their
normal uses, are discharged to sewers; others are removed from urban and
rural land areas by runoff following rainfall; and some migrate to ground-
waters by deep soil percolation. These materials may also be disposed
of, either deliberately or accidentally, by dumping in sewers or on the
land. Regardless of the route followed, many consumer products ultimately
reach our Nation's streams, lakes, estuaries, and groundwaters.
The impact on water quality of such a vast array of manufactured products
discharged to our Nation's waters is not known in any detail. It is pos-
sible that some commonly used products have a deleterious effect on re-
ceiving waters, which is not presently known or recognized. It is further
possible that harmful effects result from decomposition products or
secondary products created by synergism during their normal uses. As a
means of identifying such products, a Catalog has been prepared of manu-
factured products that have water pollution potential, and which may be
discharged to streams, lakes, estuaries, and groundwaters.
NEED FOR THE CATALOG
Extensive water pollution iSj in part, a result of the proliferation of
products containing synthetic organic and inorganic compounds. Many of
these compounds and products are toxic or have an adverse effect on eco-
logical life cycles.
To understand the potential magnitude of the water pollution problem posed
by the proliferation of consumer products, one needs only to look at the
growth in production of two categories of products. Pesticides and surface-
active agents—primarily detergents—have shown growth rates far out of
proportion to population growth over the past 20 years. The widespread
adoption of home laundry units and dishwashers has resulted in an increase
in the usage of detergents far beyond that attributed only to the increase
in population. Practically all of this detergent load is discharged
through our sewers and into our waterways.
Pesticides and surface-active agents are not alone in their increased use.
In the past twenty years, the production of synthetic organic chemicals
in this country has increased eightfold, to over 120,000 million pounds.
Tracing the distribution and end use pattern of these chemicals is enor-
mously complicated. The Catalog represents a first step towards identify-
ing specific manufactured product classes which are or may become po-
tential sources of water pollution.
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It is well-recognized that a variety of organic and inorganic materials
can cause water pollution, and the results of the discharge of such materi-
als into the water system have been documented in many cases. Water quality
criteria may be derived with respect to physical properties (color, odor,
temperature, turbidity, etc.); inorganic contaminants (heavy metals, am-
monia, fluorides, cyanides, nitrates, nitrites, sulfates); organic con-
taminants (pesticides, herbicides, oils and greases, phenols, detergents,
etc.); chemical properties (pH, hardness, dissolved oxygen, etc.); micro-
organisms, etc. Corresponding analytical techniques for assessing com-
pliance with the criteria may also be established. Control of pollutant
levels, however, requires that potential contaminants be identified at the
source. In the case of waste-effluent streams from industrial manufacturing
processes such identification is relatively straightforward. In the case
of manufactured products, the problem is more complicated. While some
analysis of sewage and landfill effluent has been done, there is very little
data on the particular products responsible for the various chemical com-
ponents identified in the effluent streams. Detergents, pesticides, her-
bicides, and fertilizers, whether discharged to sewers, removed from land
areas by runoff, or carried to groundwaters by deep soil percolation, are
known product sources of pollutants of various kinds. However, there may
be other such product classes for which a deleterious effect on receiving
waters has not yet been recognized, or for which a deleterious effect
would only be expected if current consumption patterns increase. The Cata-
log has been compiled to aid in identifying such product classes and to
provide a framework for predicting the potential magnitude of possible
pollution problems. The Catalog has been organized both by product and
by chemical ingredient.
Certain potentially harmful ingredients are used only in very low concen-
trations in any given product, but are used in a very large number of
products. The net cumulative discharge of such ingredients from a variety
of products can therefore be significant, although disposal of a single
product type may create few problems.
SCOPE OF THE CATALOG
Product Selection.
The Catalog provides an index to finished products to be used for ultimate
consumption, which may, during their use or disposal, result in water pol-
lution. The Catalog includes all products which enter the water, either
directly or indirectly, in short times or long.
The products have been grouped in conformance with the Standard Industrial
Classification (SIC) , prepared by the Office of Statistical Standards of
the Office of Management and Budget. The SIC, which is based on indus-
tries rather than on manufactured products, is not ideal for the purposes
of the Catalog. It is so well-known and widely used, however, that there
are definite advantages to adapting it to manufactured products. In doing
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so, each industrial SIC code number is associated with products produced by
that industry. The SIC is a hierarchical classification system, in which
industries are coded by a number of digits, ranging from two to seven, de-
pending upon the level of detail required for any particular application.
For use in classifying products, the SIC cannot be employed in a consis-
tent manner, since the digital breakdown required to identify recognizably
distinct classes of finished products varies considerably from one major
(two-digit) group to another. Thus, Major Group 21, Tobacco Manufacturers,
includes three manufactured product classes, each identified by a four-
digit code number - cigarettes (2111), cigars (2121), and chewing tobacco
(2131). Within the context of the catalog, no further digital breakdown
is required. On the other hand, Major Group 28 encompasses 35 four-digit
categories; and each of the four-digit categories covers a very wide vari-
ety of products. Thus, speciality cleaning, polishing, and sanitation
preparations (2842) include household ammonia, household bleaches, cleaning
fluids, floor waxes, furniture polish, disinfectants, ink eradicators, rust
removers, shoe polish, and at least thirty other products which are iden-
tified by seven-digit numbers in the classification scheme. In preparing
the Catalog, therefore, the 4, 5, 6 or 7 digit codes were used as required
to identify distinct product classes, characterizable by a small number
of typical product compositions.
In using the SIC system for product classification, one also runs into the
problem of duplicate counting. Thus, leather dyes and stains, one of the
products in Industry No. 2865, are listed separately from leather products.
It is thus difficult to separate the amount of leather dye which enters the
water supply from home and shop applications, and that which is leached
into the water supply from leather products during use and disposal. The
same problem arises with respect to synthetic dyes used in household dying
and dyes which are gradually released from colored textile products.
Similarly, processed food products, such as canned or frozen goods, are
considered as a unit, including both the food and the packaging material
in the SIC system, while the packaging materials per se are also listed in
a separate category.
Water Pollution Potential Evaluation.
Water pollution is not easy to define. Operationally, a manufactured
product must be viewed as a potential water pollutant if, during normal use
or disposal, it is discharged to sewers or washed into surface waters or
groundwaters, and thereby contributes to excessive concentrations of sub-
stances, which:(1)
1. Demand large amounts of oxygen for their decomposition;
2. Give rise to infectious diseases;
3. Promote the growth of algae and water weeds;
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4. Are acutely or chronically toxic to plants, wildlife, domestic
animals or humans;
5. Interfere with natural stream purification;
6. Cause the water to become hard;
7- Make the water corrosive;
8. Give rise to sediments or increased solids;
9. Render the water supply unaesthetic with respect to color,
turbidity, odor or general appearance; and
10. Overburden water treatment facilities.
For each of the manufactured product groups in the Catalog, chemical com-
positions are given wherever possible. Prediction of the water pollution
potential associated with the use and disposal or products containing the
various chemical substances, however, presents a number of practical dif-
ficulties. The water-pollutional effects of any substance depend not only
on its chemical composition, but also on its concentration and rate of
entry into the water. Furthermore, even in cases where concentrations or
rates of discharge are known or can be predicted, there is often no straight-
forward correlation with potential water pollution problems.
One of the important factors which is difficult to predict is biological
concentration of chemicals which become incorporated in simple or complex
food chains. A well-documented example of such concentration occurs with
DDT. From water containing 0.000005 ppm DDT, fish are found to contain
2 ppm DDT and carnivorous birds 10 ppm DDT. This concentration process
has been explained by the near insolubility of DDT in water and its high
solubility in lipids and other organic materials found in plants and ani-
mals. Heavy metals, which constitute a serious form of pollution because
of their stability, are also known to be concentrated by marine organisms.
It is not easy to predict, however, what other substances might behave
similarly, and what kinds of deleterious effects might be expected.
Another important factor concerns the transformation of chemical components
as they enter into the ecological cycle. The mercury problem is one ex-
ample. Most mercury discharges into our waters are in the form of metallic
mercury, divalent mercury, phenyl-mercury, and alkoxy-alkylmercury, all
compounds of recognized toxicity. These compounds, however, can be bio-
logically converted to methylmercury, a compound of even higher toxicity.
Water pollution problems can develop very slowly by accumulation of dan-
gerous chemicals over many years in the aquatic environment, particularly
in bottom deposits. Toxic levels may persist for many years because
natural processes that degrade or dissipate toxic chemicals are very slow.
This seems to be presently the case with materials such as mercury and
chlorinated hydrocarbons.
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In preparing the Catalog, cognizance has been taken of the fact that cer-
tain types of compounds, which are components of many manufactured products,
are recognized contributors to the water pollution problem. These include:
phosphates; nitrates; chlorinated hydrocarbons; heavy metals, surfactants;
ammonia and amino derivatives; sulfides; cyanides; fluorides; strong
bases such as sodium hydroxide, potassium hydroxide and sodium carbonate;
and phthalate esters. For most of these compounds, however, the effects
are complicated and generally closely tied into the entire ecosystem.
Other dangerous chemicals or chemical classes may well be identified in
the future. The Catalog can be used as a basis for predicting the preva-
lence of such chemicals in the waste stream. It can also serve as a guide
to future research on potential pollutants.
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SECTION IV
CATALOG ORGANIZATION
The Catalog format was designed around the following considerations:
1. It is highly desirable to identify products having water pollution
potential at as early a stage as possible in order that appropriate
control measures may be initiated.
2. To aid in planning it is important that chemical and other information
related to specific manufactured products within each SIC code be
readily available.
3. It should be possible to identify cases where potential chemical pol-
lutants appear in small quantities in the formulation of a large number
of manufactured products.
4. The categorization of products by four-, five-, six-, and seven-digit
SIC numbers must vary somewhat randomly throughout the Catalog in order
to achieve adequate detail. Thus, for cigarettes (2111), the four-
digit code is sufficient; for hair dyes, which fall into the 2844 cate-
gory (Perfumes, Cosmetics and Other Toilet Preparations), a seven-digit
code will be needed to identify the specific product group.
Given these considerations, the Catalog has been organized in three sec-
tions :
SECTION I - SUMMARY
Section I will provide an overview of the pollution potential associated
with all manufactured products which, in normal use, are discharged into
the Nation's waterways. A sample page is shown in Figure 1. Products are
listed by SIC number and name. Usual product uses have been designated by
means of the two-digit code shown in Figure 2. This code also helps to
categorize products with respect to the pathways followed to the water.
Space is provided for specifying the various rate parameters associated
with the model described below. The purpose of the model is to provide
estimates of the rates of discharge of manufactured product components or
their degradation products into the Nation's waterways. The rates, and
the related concentration build-up, are vital to the assessment of the
probable magnitude of potential water-pollutional effects. The production
rate estimates (R) are derived from the census of manufacturers. An
attempt has been made to reduce all production figures to a common base
(millions of pounds). However, certain products do not yield to such
reduction and are given in other units, e.g., millions of board feet,
millions of cars, paint brushes, etc. When (R) has been inferred from
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SIC
NUMBER
2841653
2842
28421
2842135
2842171
28423
2842311
2842321
2842331
2842332
2842341
2842351
2842371
.. 2842394
2842395
2842396
2842397
NAME
Scouring cleansers with no abrasives
Specialty Cleaning Polishing & Sanit. Preps except Soaps, etc.
Insecticides
Repellent & Attractants (for insects, birds, and other animals)
Redenticides
Specialty Cleaning & Sanitation Products
Glass Window Cleaning Preps.
Oven Cleaners
Toilet Bowl Cleaner & Drain Pipe Solvents
Disinfectants for use other than Agricultural
Wallpaper, Window Shade & Wallcleaner
Rug & Upholstery Cleaners, Consumer
Household Ammonia
Fabric Softener
Laundry Starch Aerosol
Laundry Starch, Other Liquid
Laundry Starch, Dry
USUAL
PRODUCT
USES
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
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FIGURE 2. USUAL PRODUCT USES
Use Category
9 Personal
9.1
9.2
9.3
Cleansing
Cosmetics
Clothes
8 Agricultural
8.1
8.2
Chemicals
Machinery
7 Housekeeping
7.1
7.2
7.3
Cleaning
Food storage and
preparation
Maintenance
6 Ingested
6.1
6.2
6.3
Human
Livestock
Medicines
5 Transportation
5.1
5.2
5.3
Personal
Mass
Special Purpose
4 Construction
4.1
4.2
Exposed
Indirectly exposed
3 Professional
3.1
3.2
Exposed
Indirectly exposed
2 Recreation
2.1
2.2
Exposed
Indirectly exposed
1 Production
1.1
1.2
Exposed during use
Not exposed during use
10
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other figures, or is given in units other than millions of pounds, an as-
terisk is used.
There are no readily accessible tabulations of the product lifetime (L);
and, in fact, the definition, for purposes of the Catalog does not corre-
spond with the normal concepts used in industry. For example, "product
lifetime" is thought of by some sectors of industry as that period of time
during which it is profitable to continue producing the particular product.
For example, "Kelloggs1 Pep" had a "product lifetime" of a decade or two
by the industrial concept. For the purposes of the Catalog, however, the
average lifetime (L) of Pep would be a matter of months and would incorpo-
rate the time between completion of the manufacturing and packaging (i.e.,
the registering as part of the annual production, R, and the time the
cereal was totally consumed. Part of L, then, is made up of warehouse and
home-storage time, as well as the time during which the product is actually
used.
Due in part to our definition of L and in part to the lack of any systematic
tabulation of quantities even qualitatively related to L, we have had to
estimate these quantities on the basis of our own knowledge of the products.
Q1, which is simply the product of R and L, represents the amount of each
product in use at any particular time.
The columns headed k^L, k-^L, and a-^L represent respectively the percen-
tages of each product which (1) enter the water directly (k^L); (2) are
transferred to secondary reservoirs where they may be indirectly transfer-
red to the water by leaching or carried down by rainfall (k-^L); and (3)
degrade during use or otherwise become chemically transformed. These
percentages are not known accurately but can be estimated in most cases
to better than an order of magnitude.
The final columns of Section I give a rough indication of the types of
water-pollutional effects that might be associated with the use and dis-
posal of each product. Qualitative ratings are provided where available
on potential water pollution problems that might result from ingredients
of the product which are toxic, have high oxygen demand, lead to increased
solids loading, are colored, have an objectionable odor, lead to eutro-
phication, are oily or tarry, or tend to increase water hardness.
Toxicity is particularly difficult to define since many types of acute
and chronic effects on plant life, fish, wildlife, as well as humans are
possible and may be significant from the point of view of water quality.
The wide diversity of materials which enters into the manufacture of al-
most every modern product today offers many sources of potential water
pollution. In the first place, the definitions of "water pollution" are
not unique and lead to the possibility that any one material or product
may contribute on more than one basis. For example, dyes may have toxic
properties as well as causing unnatural colors in the water. A particular
11
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product may contain dye, contribute to suspended solids, and change the pH
of the water all at the same time. In addition, there may be subtle, as
yet unrecognized, ways in which a product causes water pollution.
SECTION II - PRODUCT LISTING
In Section II, more detailed information is provided with respect to the
pollution potential associated with each of the manufactured products tabu-
lated in Section I. A sample page is shown in Figure 3. Each product
category is identified by a heading which gives SIC number and name. One
or more typical chemical compositions and weight percentage range are pro-
vided, and each ingredient in the formulation is rated for water pollution
potential. If any chemical ingredient is a potential water pollutant
(denoted by an X in any column), then an X also appears in the corresponding
column of Section I.
SECTION III - CHEMICAL COMPOUND LISTING
Section III is, in a sense, an inversion of Section II. A sample page is
shown in Figure 4. The ingredients or chemical compounds used in formula-
ting the manufactured products under consideration are listed alphabetically
in the first column. The product classes in which such ingredients are
found are identified by SIC number in column 2. Column 3 groups each of
the ingredients into one of the general chemical classes listed in Table I.
The grouping by chemical class is somewhat arbitrary, with the underlying
principle that of concern for water pollution. Thus, mercuric acetate is
a metal salt, while sodium acetate is a fatty acid derivative. In cases of
ambiguity, where a compound may properly be assigned to two classes, both
are listed. The reason for providing a general chemical classification is
that data are frequently not available for a specific chemical compound,
but members of a generic class may tend to exhibit similar water-pollutional
effects. Notes on properties that may effect chemical potential are pro-
vided in the fourth column of Section III. When TOX or BOD appear under
NOTES, additional data related to toxicity and biological oxygen demand,
respectively, are given by chemical class in Appendices A and B of Section
III.
12
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M
3942 053
STUFFED TOY ANIMALS
TYPICAL CHEMICAL COMPOSITION
"Dream Pets"
Mixed Sawdust
Spruce
Fir
Pine
Sugi
Cotton Fabric
from Evergreens
(See SIC 2261)
Dye (See SIC 2261)
%
all
cause
derma-
titis &
allergic
reac-
tions
suspect
REF.
Cons Rptz.
3/72
^H
M
0
M
X!
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REF.
CCD
CCD
Heukelekian
x - may be an effect
o - no effect
blank - no information
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Q
COMPOUND
Abrasives
Acacia
(See: Gum Arabic)
Acetal copolymers
Acetic acid
CH COOH
PRODUCT
SIC
2841 175
2842 3
2842 498
3941
1925
2519
2591
3079
3079 65
3652
3941
2111
2279
2842 332
2842 398
2842 442
2844 351
2844 519
2891 1
2899 3
3861 811
3941
CHEMICAL
CLASS
Condensation
polymers
Aliphatic acid
NOTES
Examples: Boron Carbide
Boron Nitride
Cor and um
Diamond
Garnet
Tripoli
Silicon Carbide
Clear, colorless, acid liquid
Very pungent odor
Miscible with water
Causes severe burns
Oxygen demand
REFERENCE
CCD
CCD
CCD
CCD
CCD
Heukelekian
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TABLE I. CLASSES OF CHEMICAL COMPOUNDS
1. Mineral acids
2. Aliphatic (fatty) acids
3. Aromatic (benzene) acids
4. Rosin acids
5. Alcohols
6. Aliphatic hydrocarbons (petroleum derivatives)
7. Aromatic hydrocarbons (benzene derivatives)
8. Sulfonated hydrocarbons
9. Halogenated hydrocarbons (mostly chlorinated hydrocarbons)
(the aliphatic are not persistent;
the aromatic are)
10. Alkaloids
11. Ammonia, aliphatic amines and their salts
12. Anilines (any compound having nitrogen attached to a benzene-ring)
13. Pyridines (all sorts of nitrogeneous hetercycles)
14. Phenols
15. Aldehydes
16. Ketones ;
17. Fluorine compounds
18. Organic sulfur compounds (sulfides, mercaptans)
19. Organometallic compounds (do not degrade easily)
20. Chlorine and hypodilontes
21. Cyanides - because of unusual toxicity
22. Thiocyanates - because of toxicity
23. Synthetic coloring matters
24. Sterols
25. Sugars and cellulose
26. Addition polymers - (do not degrade, since have hydrocarbon
or ether backbones)
27. Condensation polymers - degrade, since are polyamides, polyesters
28. Inorganic bases (excepting ammonia)
29. Metals, metal acids and metal salts - only when metal is known to be
toxic.
15
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SECTION V
MODEL FOR ESTIMATING RATES OF DISCHARGE OF POTENTIAL POLLUTANTS
In order to provide a realistic basis for a quantitative estimation of the
amount of material which enters the water during the normal use and dispo-
sition of specific products, we developed a simple model which takes into
account rates at which products enter the water via different paths.
It is only recently that much concern has been placed on determining the
ultimate fate of any particular set of manufactured products. Because this
is true, statistics which would allow one to evaluate a product for its
pollution potential are not generally available. The types of figures one
can obtain relate to annual production rates, and the amounts and types of
various raw materials used in the production. The production rate repre-
sents the maximum rate at which the particular industrial segment could
possibly be polluting the waters with manufactured products and their by-
products. However there are many industries which have extremely large
annual production figures whose products probably contribute relatively
little to pollution problems because of the way the products are used, or
decay, before entering the water. Extremely large quantities of gasoline,
for example, are produced each year. However, most of it is burned before
having access to water; and thus the large annual production figures do
not give a direct, and accurate, assessment of gasoline's pollution poten-
tial.
In order to evaluate the pollution potential of such products, it is neces-
sary to have a conceptual framework into which apparently diverse kinds
of information can be placed for inspection. The model we have developed
serves this purpose.
The model is based on two reservoirs, and six rate parameters as indicated
in Figure 5. Manufactured products are generated at a rate of R Ibs/yr.
At any given time, Qx pounds of product will be in use in the consumer
product market or primary reservoir. As the product is consumed, it may
leave the primary reservoir by a variety of routes, three of which are
considered in this simple model. The product, or a portion of it, may be
discharged to the water directly through sewers or by runoff following
rainfall at a rate S Ibs/yr. Some or all of the product may degrade
during use at a rate S-Q Ibs/yr. A third fraction of the product may be
transferred at a rate S-^ Ibs/yr to a secondary reservoir, which might be
a dump or the air or a solid surface, from which further discharge or
degradation may occur. The amount of product stored in the secondary
reservoir at any time is Q2 Ibs, of which $2 Ibs/yr leave the reservoir
and enter the water directly; and S22 Ibs/yr are degraded to another form
in the reservoir.
The two-reservoir model is clearly an oversimplification. The amount, Q2,
may, in fact, be the sum of quantities stored in a number of secondary and
tertiary reservoirs, the "decay periods" of which vary a great deal. For
16
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FIGURE 5. TWO-RESERVOIR MODEL OF POTENTIAL WATER-POLLUTIONAL PATHWAY
R : Annual production rates (Ibs/yr)
Q : Amount of product in use at a particular time (Ibs)
S.. : Rate at which the product enters the water directly (Ibs/yr)
S : Rate at which the product degrades while in use (Ibs/yr)
S „: Rate at which the product is transferred to the secondary reservoir
(dump, volatilized to be leached by rain, etc.) (Ibs/yr)
Q : Amount of product stored in secondary reservoirs (Ibs)
S« : Rate at which the product enters the water from secondary reservoir
(Ibs/yr)
S?,,: Rate at which the product degrades in the secondary reservoir (Ibs/yr)
17
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example, a portion of the products which make up solid waste may be dis-
posed of in a dump, while another portion may be disposed of through
incineration. The incinerated portion may liberate undesirable by-
products which are washed down by rainfall in a relatively short "decay
period" while that portion residing in dumps is subject to leaching over
a much longer period. The model can readily be extended to cover speci-
fic cases in more detail; but even in the simple form presented here, use-
ful predictions can be made.
As indicated above, some products in their normal use are disposed of
directly into the water. The model assumes that the rate of such disposal
is proportional r.o the amount in use at any time, i.e., the amount in the
rD.rst reservoir. Some products, such as gasoline, are changed chemically
during their use into non-polluting substances. It is assumed that the
rate at which this change is. made also is proportional to the amount of
product in the first reservoir. Some of almost every product is not used
but winds up in a dump or other kind of intermediate storage (the second
reservoir). The rate of transfer from one reservoir to the next is also
assumed to be proportional to the amount of product in the first reser-
voir. We may thus define further the rates (S) at which the product
leaves the reservoirs by the various routes as follows:
(1)
S12 - k!2Ql S22
where the k's and a's are fractional proportionality constants with
dimensions of years" .
The rates of change with time of the quantities Q-, and Q? in each res-
ervoir are given by the difference between the rate at which product enters
each reservoir and the rate of loss of product from the reservoir as
follows:
dQl
— + (4 + k12 + Ol) QI = R (2)
4-C\f+f\\o=lfri /o\
T \f--r: ~ Utoy l^o — K.1 „ 1^- I J I
dt 2 2 2 12 1 v
18
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The quantity I/ (cu + k-, + k-i-j), which has dimensions of years may be inter-
preted physically as the average lifetime, L, of a product in the primary
reservoir or the average time between manufacture of a product and its
discharge from the primary reservoir. Similarly, I/(do + k~) represents
the average decay time, D, for products in the secondary reservoir. In
terms of D and L, the solutions to Equations (2) and (3) are:
Q1 = RL [l-£~t/L] (4)
Q2 = k12 RLD
D rt/D L E~t/L
1 + V^ir-r^ I <5>
dQ dQ2
Under steady-state conditions (t •> °° or —-— = —— = 0) , Qn and Q0 assume
i ........ dt dt 1 i
limiting yalues given by:
V lim = ^ (6)
^2, lim = k!2 D Ql, lim (7)
The limiting values of Q-^ and Q~ from Equations (6) and (7) may be sub-
stituted into the set of Equations (1) to obtain the limiting values of
S, the rates of discharge and/or degradation from the two reservoirs -.
It may be noted that the total output from the primary reservoir in Ibs/yr
is given by the sum (S-^ + S-Q + ^12^ = ^1 + al + ^12^ Q!' Hence, the
fractions of product lost from the primary reservoir via each of the three
routes considered are, respectively, k-^L, a^L, and k-^L. Estimates of
these quantities are provided in Section I of the Catalog. It should be
pointed out the percentage error in S^, the rate of discharge of product
directly into the water, will be approximately the same as the percentage
error involved in estimating product lifetime, L.
Convenient forms for calculating rates of discharge based on the model
are provided in Section VI.
19
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SECTION VI
HOW TO USE THE CATALOG
The Catalog was designed with the following major uses in mind:
1. Identification of manufactured products, which, during normal use and
disposal, may contribute to water pollution.
2. Identification of the potentially deleterious chemical ingredients used
in the formulation of such products.
3. Alternatively, determination of the manufactured products which typi-
cally contain specific recognized or suspected polluting substances.
4. Semi-quantitative estimation of the rate of discharge of products or
pollutants into the water and the resultant concentration levels.
Several specific ways in which the Catalog might be used are presented
below. Other applications may be expected to develop with increased famil-
iarity.
Section I of the Catalog serves as a summary in which each product group
is listed in tabular form according to the SIC code of the corresponding
manufacturing industry. Specific ingredients or compounds which cause the
pollution are not indicated. This section serves only to draw one's at-
tention to various SIC codes which may, for one reason or another, appear
to require more detailed investigation. More explicit data may then be
obtained by referring to Section II of the Catalog.
If, for example, a product is suspect, or under investigation for associ-
ated water pollution potential, one wants to determine which ingredients
of the product are responsible for polluting effects. Section II of the
Catalog fills this need by listing typical chemical compositions of pro-
ducts contained in the various SIC codes. There are numerous formulations
(many of them proprietary) for most of the products listed in the Catalog.
No attempt is made to list all formulations for which data are available.
A subjective selection of known formulations was made to be included in
the "typical chemical composition" list. In addition to noting the "typi-
cal" percentage of each component, the polluting characteristics of each
are noted in the same manner as in Section I of the Catalog. References
are given for both the "typical composition" and the pollution character-
istics data.
Once a particular substance has been identified as a potentially important
pollutant, it is often of interest to determine its ubiquity, or the
number of products in which it occurs. Section III of the Catalog, which
is an inversion of Section II, allows this to be done. Here, the chemicals
are listed alphabetically; and the products in which they typically occur
are listed by SIC code. It is thus possible to identify each of the
20
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product classes which contain, for example, fluorides, various halogenated
hydrocarbons, various heavy metals, given toxic or hazardous substances,
suspected biorefractories, etc.
The product and chemical formulation information which may be obtained from
Sections II and III of the Catalog by direct inspection, can be useful in
itself. However, before a very meaningful assessment of pollution poten-
tial can be rendered, a more detailed understanding of the routes followed
by the pollutant products on their way to the watar, and the relative rates
at which they are transported is necessary. During the Catalog's develop-
ment, a simple model evolved which provides a framework for estimating
some of these factors.
The mathematical framework of the model was discussed in the preceding
section. Here, we indicate its method of use.
In Section I, space is allowed for information on annual production rates
(R) of the listed product groups. Whenever practicable, production is re-
ported in pounds per year, as required for estimating discharge rates via
the model. Section I of the Catalog also includes space for (and in some
cases, our own estimates of) the percentage of the total production which,
during use and disposal, flows: a) directly into the water, b) into the
second reservoir, and c) is chemically decomposed during use.
The model comprises two "reservoirs" which represent, respectively, the
amount of a product in use at a particular time, and the amount of a pro-
duct which is no longer in its initial state of use, but is in some kind
of intermediate storage. The first step in using the model for predictive
purposes is to define the "reservoirs" for the particular product or
product class of interest. From the time a finished product leaves the
manufacturer's shelf up to the time when the consumer is through with the
product, it may be considered to be in circulation in the "first reser-
voir." The annual production feeds the first reservoir, and the amount
accumulated is equal to the annual production rate (R, Ib/yr) times the
"lifetime" of the product (L, expressed in years).
The "second" reservoir may be defined by a consideration of the output
from the first reservoir. It is helpful to construct a flow diagram of
the type indicated in Figure 6 for any product of interest. After the
product has been consumed, or is no longer usable, a fraction (k-^L) may
be discarded directly into the water at a rate S]_ = k^P^. A second frac-
tion (k^2^) may be stored in various types of "second" reservoirs, which
should be specified. The product might, for example, typically be sent
to a dump. It might, like fertilizers and herbicides, be spread on the
ground from which runoff might occur. It might, like exterior house paint,
be functional for a time, although no longer "usable." A given product
may enter into several different types of "second" reservoirs; and, in
any case, the pollution potential due to outflow, S-^» from the set of
second reservoirs can be quite complicated to evaluate. Finally, a
fraction (a..L) of the original product may degrade during use at a
21
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FIGURE 6 : FLOW DIAGRAM OF PRODUCT ROUTES
PRODUCT NAME:
R =
SIC Number
Ibs/yr
Product in Use (Q Ibs)
First Reservoir
*Insert typical uses
Fate of the Product when it becomes Unusable
Water
CM
^ f
Product in
Storage**
Second
Reservoir
Degradation
Products***
**Insert mode of
"storage" - e.g.
Dump, Spread on
ground.
Functional (e.g.
paint on walls); etc.
***Insert type of
Degradation
22
-------
rate S;Q = a^Qj; and a new flow sheet can be constructed for the degrada-
tion products.
A form is provided in Figure 7 for calculating the rates at which products
leaye the first reservoir via the various routes defined in Figure 6.
An example of the use of the forms in Figures 6 and 7 to evaluate the
quantity of fluoride which may enter the water from the use and disposal
of fluoridated toothpaste is presented here. The first step is to find
toothpaste in the SIC manual.(2) it falls under the SIC four-digit code
2844. By scanning the 2844 entries in Section I of the Catalog, toothpaste
is coded specifically as SIC 2844 11. A flow diagram is constructed as in
Figure 8. In Section I, the annual production rate is given as 177.3 x 10^
pounds/year. This figure refers to all toothpaste. We are interested, in
the example at hand, in fluoridate^ toothpaste. A little research tells us
that in 1963 fluoride toothpaste had captured 1/3 of the market. Today, we
might assume that half the toothpaste sold is fluoridated. Therefore,
Figure 8, R = 88.6 x 106 pounds/year (177.3 x 106 x 1/2) is inserted. The
product use is fairly obvious; and all the toothpaste, except that remaining
in the tube, goes directly down the drain. The residual toothpaste, in its
containing tube, typically goes to the dump, where it may decay further.
Steady-state rate calculations are carried out as indicated in Figure 9,
using the following data as provided in Section I.
Lifetime: L = 0.5 yrs
Decay time (in the dump): D = 20 yrs
Percent degraded: a L =_ 0
Percent entering water directly: k L = 95
Percent stored in the dump: k.. ?L = 5
By referring to Section II of the Catalog, we determine that toothpaste
typically contains about 0.2% fluoride.
We see in Figure 9 that the calculated rate of discharge of fluoride di-
rectly into the water from use of fluoridated toothpaste is 16.8 x 10^ Ibs/yr
or 461 Ibs :of fluoride per day for the Nation as a wholei To evaluate this
daily rate -of fluoride introduction into our waterways, we will estimate
the concentration level by comparing it with the amount of water drawn off
and replaced during municipal and rural domestic use. The Water Encyclo-
pedia indicates that 19.216 x 10^ gallons of water per day are withdrawn,
used and replaced for these purposes in the U. S. Assuming 8.3 Ibs/gallon,
this converts to 1.6 x 10 Ibs/day, indicating an average concentration of:
> .q-= 2,88 ppb
160 x 10
23
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FIGURE 7. CALCULATION OF STEADY STATE RATES OF DISCHARGE
OF POTENTIAL POLLUTANTS FROM FLUORIDATED TOOTHPASTE
A. Disposal from the Primary Reservoir
Annual production rate of the product R =
% of fluoride (x)* in the product %x =
Fraction of product discharged
directly to the water k^L =
Fraction of product decomposed
during use ct-,L =
Fraction of product stored in a
secondary reservoir after use ^12^ =
Product lifetime L =
k!2 =
Amount of produce in circulation
for consumer use (steady state) Q = (R) (L)=
_L 5 S S
Rate at which fluoride (x)* is:
Discharged directly into the water S-. = (k ) (Q ) (%x) =
100
Decomposed during use S .. = (a ) (Q ) (%x) = (0) (Q,) (%x)
Stored in a secondary reservoir
after use S12 = (k12> (Q1) (%x)
B. Disposal from the Secondary Reservoir
Fraction of product leached or
washined directly into the water k?D
24
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FIGURE 7. (Cont'd)
Fraction of product decomposed
in the reservoir a_D
Decay Time D
Rate constants k?
Amount of product in the secondary
reservoir (steady state) 0. = kn „ D Qn
2,ss 12 l,ss
Direct discharge of fluoride* from
the secondary reservoir to the water S9 = (k9) (Q9) (%x)
100
Rate of decomposition of fluoride*
in the secondary reservoir S99 = (a9) (Q9) (%x) = 0 Ibs/yr
100
*Insert the name of the chemical ingredient of interest
25
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FIGURE 8: FLOW DIAGRAM OF PRODUCT ROUTES
PRODUCT MAW.? Floridated Toothpaste
R= 88.6 x 10
Product in Use (Q Ibs)
* Brushing teeth
First Reservoir
SIC Number
2844 11
Ibs/yr
*Insert typical uses
Fate of the Product when it becomes Unusable
Water
95%
a1
Product in
Storage**
Dump 5%
Second
Reservoir
Degradatioi
Products**
None
**Insert mode of
"storage" - e.g.,
Dump, Spread on
ground.
Functional (e.g.,
paint on walls); etc.
***Insert type of
Degradation
26
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FIGURE 9. CALCULATION OF STEADY STATE RATES OF DISCHARGE
OF POTENTIAL POLLUTANTS FROM FLUORIDATED TOOTHPASTE
Disposal from the Primary Reservoir
Annual production rate of the product
% of fluoride (x)* in the product
Fraction of product discharged
directly to the water
Fraction of product decomposed
during use
Fraction of product stored in a
secondary reservoir after use
Product lifetime
Rate Constants
R = 88.6 x 10 Ibs/yr
%x = 0.2%
L = 0.95
-------
FIGURE 9. (Cont'd)
Fraction of product decomposed
in the reservoir
Decay Time
Rate constants
Amount of product in the secondary
reservoir (steady state)
a£D = 0
D =20 yrs
k = 0.05 yrs
-1
-1
= 0 yrs
Q2,ss ' k!2
l,ss
= (0.1) (20) (44. 3 x 10) =
= 88.6 x 106 Ibs
Direct discharge of fluoride* from
the secondary reservoir to the water S? = (k^)(Q7)(%x) =
100
= 0.05(88.6 x 101
Rate of decomposition of fluoride*
in the secondary reservoir
(0.002) =
88.6 x 10 Ibs/yr
S99= (aJ(QJ(%x) = 0 Ibs/yr
zz 100
*Insert the name of the chemical ingredient of interest
28
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The potential outflow of fluoride from the dump is far from negligible,
and. in fact, under steady-state conditions Q2 exceeds Q^ by about a fac-
tor of two. On the other hand, fluoride leached from a dump would probably
be tied up with calcium in the soil and is not likely to contribute signi-
ficantly to the fluoride concentration in the water.
It is instructive to consider the build-up of Q^_ and Q2 to steady-state
conditions. The result of such a calculation, based on Equations (4) and
(5) are given in Figure 10. We note that steady-state is closely approach-
ed in about a decade for this particular example.
th general, for a constant production rate, R, starting at t = 0, 0^ rises
exponentially to its asymptote, RL; Q2 lags Q^ by k12 D and follows an "S"
shaped curve. Plots of Q^/R and Q2/R as a function of dimensionless time
t = t/L are given in Figure 11 for the case L = 1 yr; D = 10 yrs; and k 9L =
0.5. LL
Generalized plots of Q^/RL and Q]_2/k12 RDL for D/L = 10, 20, and 40 are
given in Figure 12.
One important use for the Catalog and model is to roughly evaluate the
total amount of a particular substance which enters the environment through
the use of manufactured products. By consulting Section III, one can find
the SIC numbers for all manufactured products formulated with any particu-
lar chemical. In Section II, the amount of that chemical in the various
formulations can be found, while production figures and model parameters
are given in Section I.
In general, the Catalog and associated model can be used as a tool to
evaluate the relative seriousness of a product's pollution potential as
a result of:
A - direct entry into the water through sewers or into streams and waterways,
B - secondary accumulations, as in dumps or other reservoirs, where large
quantities may build up, and
C - decomposition or chemical change during use or disposal.
It can further be used to estimate the criticality of a potential pollution
problem by determining the time constants associated with it. In addition,
it can serve as a predictive tool to estimate the order of magnitude of
product quantities which are released into the water by each route.
The amount stored, and the rates at which transfers of products and their
component substances takes place from one reservoir to the next, and from
reservoirs into the Nation's waters are the real quantities of interest.
The rates are proportional to the amount contained in the reservoirs,
which in turn depend on the "lifetime" and "decay," or "release" time
for the first and second reservoir, respectively. If a large percentage
29
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to
o
X
>
+-l
c
03
a
200
180
160
140
120
100
80
60
40
20
i I I i I i i i I I I I i 1 I i i i i i
0 123 4567
! 9 10 11 12 13 14 15 16 17 18 19 20 21
Time (years)
FIGURE 10
30
-------
Q
R
7
Q2/R
0,/R
8 10 12 14 16 18 20 22 24 26 28 30
t =t/L
FIGURE 11
-------
or
FIGURE 12
-------
of the product ends up in storage in reservoir two, and it also has a large
"decay" time, a serious pollution problem could be building up over a
period of years as the stored quantity gradually builds up to an equili-
brium value. The problem may not be perceived as such because very small
quantities of the polluting material enter the water directly. DDT is ah
example of one such case where the amount of product entering the water
directly each year appears to be relatively small and therefore of little
significance. However, due to its persistence (and effectively long "decay1
time) it has built up in reservoir two over a number of years to the point
where serious consequences are now recognized. The alternative case occurs
for products such as toilet bowl cleaners. In this case, nearly all of
the product enters the water rapidly and directly. It is necessary to
estimate the time scale in which a particular product may represent a
pollution hazard. This must be done in order to determine whether it is
the direct, short-term effects which are most critical, or whether the
potential is for a greater, long-term problem.
33
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REFERENCES
(1) C. G. Wilbur, The Biological Aspects of Water Pollution,
Charles C. Thomas, Springfield, Illinois (1969).
(2) Standard Industrial Classification Manual, 1972, Super-
intendent of Documents Stock Number 4101-0066.
«U.S. GOVERNMENT PRINTING OFFICE. 1973 514-154/290 1-3 34
-------
1
Accession Number
w
5
2
Subject Field & Group
05B
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
A. T). T.i<-t-~lo Tnr-
Cambridge, Mass. 02140
ntie
Assessing the Water Pollution Potential of
Manufactured Products
10
Author(s)
J. B. Berkowitz
G. R. Schimke
V. R. Valeri
16
Project Designation
16080 GNC
21
Note
22
Citation
Environmental Protection Agency report
number, EPA-R2-73-179, April 1973.
23
Descriptors (Starred First)
* Water Pollution Sources, * Municipal Wastes, * Domestic Wastes, * Heavy Metals,
* Pollutant Identification, * Pollutants, * Sewage, * Waste Identification,
* Wastes
25
Identifiers (Starred First)
* Manufactured Products
27
Abstract
A Catalog has been compiled of manufactured products which may, during
their normal use or disposal, results in water pollution. The Catalog is
in three sections, and the products are grouped in accordance with the
Standard Industrial Classification (SIC).
Section I summarizes the pollution potential of each listed product group.
Section II provides data on typical chemical compositions for each pro-
duct group and indicates the types of water-pollutional effects associated
with each chemical ingredient. Section III inverts Section Hby providing
an alphabetical listing of chemicals and the SIC codes in which they occur.
Along with the Catalog, a simple model has been developed to estimate
rates of pollutant entry into the waterways, via various routes. A guide
including examples is provided on how to use the Catalog and associated
models to assess potential water pollution problems arising from finished
products in common use.
Abstractor
Institution
A. D. T.-irt-lc. inc.
WRM02 (REV. JULY 1969)
WRSIC
SEND. WITH COPY OF DOCUMENT, TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C, 20240
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