POLLUTION IMPLICATIONS OF
ANIMAL WASTES --
A FORWARD ORIENTED REVIEW
U. S. DEPARTMENT OF THE INTERIOR
FEDERAL WATER POLLUTION CONTROL ADMINISTRATION
ROBERT S. KERR WATER RESEARCH CENTER
ADA, OKLAHOMA
JULY 1968
-------
POLLUTION IMPLICATIONS OF
ANIMAL WASTES--
A FORWARD ORIENTED REVIEW
Prepared by
DR. RAYMOND C. LOEHR
Professor of Water Resources
and Agricultural Engineering
Cornell University
Ithaca, New York 14850
for
Research Program
Robert S. Kerr Water Research Center
Ada, Oklahoma
U. S. DEPARTMENT OF THE INTERIOR
Federal Water Pollution Control Administration
July 1968
-------
FOREWORD
Reflecting the increasing concern of the people of the United
States, the Congress has, since 1948, provided legislation to combat
water pollution. This concern eventually culminated in the Water
Quality Act of 1965 which established the Federal Water Pollution
Control Administration to carry out the Federal program for
renovation and protection of our Nation's water resources. Pollution
from animal wastes is a relatively new but rapidly expanding threat
to these resources and requires an immediate response.
Although the total volume of animal waste produced in the
United States is about ten times that of the human population,
little concern has resulted until the last decade. Previously,
most animals were produced in unconfined areas where wastes could
be assimilated by the environment with little or no detrimental
effects. The recent logarithmic increase in concentrated feeding
operations and the ever greater proximity of these operations to
metropolitan areas has overtaxed the natural assimilative capacity
of producing areas and demanded control of resulting effluents.
Even now, the implications of the animal waste problem are
not fully realized by the general public, livestock operators, or
by many scientists concerned with water pollution control. Waste
management technology continues to lag behind the rapid growth of
the livestock industry, and the gap widens. The reversal of this
-------
trend and prevention of uncontrolled pollution of this Nation's
most valuable natural resource demand, as the first step a greater
awareness of the problem.
The following report discusses the magnitude of the problem,
presents presently applicable technology, and outlines areas where
additional information is needed. The immediate goal is to concen-
trate problems and possible solutions of animal waste management
into a document of benefit to the livestock producer, researchers,
and other individuals or agencies concerned with water pollution
control. The ultimate goal is the restoration and maintenance of
the Nation's water at a quality commensurate with the will of the
people and the technology of which we are capable.
Marion R. Scalf
Research Sanitary Engineer
Robert S. Kerr Water Research Center
At the time this paper was prepared and until February 1, 1968,
Dr. Loehr was Professor of Civil Engineering at the University
of Kansas, Lawrence, Kansas.
-------
CONTENTS
Page
CONTENTS i
LIST OF TABLES iii
LIST OF FIGURES vi
SUMMARY RECOMMENDATIONS vii
PART 1 - REASONS FOR THE STUDY 1
PART 2 - INTRODUCTION 3
PART 3 - TRENDS IN ANIMAL PRODUCTION 9
Meat Consumption „ 9
Livestock Inventory 9
Production Units 16
Summary 22
PART 4 - MANURE PRODUCTION 24
General 24
Effect of Ration 25
Physical and Chemical Characteristics 30
Pollutional Characteristics 36
Population Equivalents 38
Magnitude of the Problem 41
Summary 51
PART 5 - POLLUTION HAZARDS 54
Introduction 54
Organic Pollution . 54
Inorganic Pollution 60
Health Aspects 63
Additional Problems 65
Summary 67
PART 6 - WASTE TREATMENT AND DISPOSAL 69
Introduction 69
Anaerobic Digestion 70
Aerobic 73
Anaerobic Lagoons 81
Anaerobic - Aerobic Systems 89
-------
Page
Land Disposal 90
Incineration and Drying 93
Miscellaneous Processes 95
European Practice 101
Summary 105
PART 7 - COSTS 110
Introduction 110
Animal Production Costs and Profits HO
Animal Waste Treatment Costs 117
Treatment Process Cost Comparison 120
Evaluation of Compared Processes 135
Summary 142
PART 8 - LEGAL 145
Federal 145
State 146
Local 148
Great Britain 148
Summary 150
PART 9 - SUMMARY AND RECOMMENDATIONS 151
Summary 151
Recommendations 154
REFERENCES 165
ii
-------
LIST OF TABLES
Page
1. PER CAPITA CONSUMPTION OF MEAT--1966 11
2. FARM ANIMAL POPULATION OF THE UNITED STATES 12
3. DISTRIBUTION OF BEEF PRODUCTION 16
4. FARM AND LIVESTOCK PROJECTIONS--PACIFIC NORTHWEST--
1960-1966 ...... 22
5. NUMBER AND CAPACITY OF CATTLE FEEDLOTS--1962-1964 ... 23
6. ANIMAL WASTE CHARACTERISTICS 31
7o LIVESTOCK WASTE CHARACTERISTICS . . „ 31
8. POULTRY WASTE CHARACTERISTICS 32
9. NUTRIENTS IN ANIMAL WASTES 33
10, CHARACTERISTICS OF ANIMAL MANURES 33
11. NUTRIENTS IN FRESH ANIMAL MANURES (Ib./lOOO gal) .... 34
12. SEASONAL VARIATION OF HOG MANURE CHARACTERISTICS .... 34
13. POLLUTIONAL CHARACTERISTICS OF ANIMAL WASTES--
WEIGHT UNITS 39
14. POLLUTIONAL CHARACTERISTICS OF ANIMAL WASTES--
CONCENTRATION UNITS 40
15. WASTE CHARACTERISTICS OF A 900 POUND STEER 41
16. CHARACTERISTICS OF FARM EFFLUENTS 42
17. POPULATION EQUIVALENTS OF ANIMAL WASTES--
BOD5 BASIS 43
18. POPULATION EQUIVALENTS OF ANIMAL WASTES 44
19. AVERAGE ANIMAL WASTE CHARACTERISTICS 45
20. EQUIVALENT POPULATION OF ANIMALS (1960) 47
21. EQUIVALENT POPULATION OF ANIMALS IN THE UNITED STATES
(1960) 48
iii
-------
Page
22, EQUIVALENT POPULATION OF ANIMAL WASTES GREATER
THAN HUMAN POPULATION 49
23, FISH KILLS ATTRIBUTED TO ANIMAL WASTES 56
24, FOX CREEK NEAR STRONG CITY, NOVEMBER 1962,
WATER QUALITY PARAMETERS 60
25. ESTIMATE OF NUTRIENT CONTRIBUTION FROM VARIOUS SOURCES . 62
26, CHARACTERISTICS OF MIXED LIQUOR—ANAEROBIC
DIGESTION OF ANIMAL WASTES 74
27, PERFORMANCE OF ANAEROBIC LAGOONS 86
28. EFFLUENT QUALITY OF ANAEROBIC LAGOONS TREATING
LIVESTOCK WASTE 86
29. CHARACTERISTICS OF BOTTOM SOLIDS--ANAEROBIC
LAGOON UNITS 88
30. CATTLE FEEDING SYSTEMS--L951-1963 112
31. COST OF CATTLE FEEDING OPERATIONS 115
32. AVERAGE PRICE MARGIN 116
33, INVESTMENT AND ANNUAL COST FOR SHORT FED
YEARLING STEERS 116
34. ECONOMIC EVALUATION OF LIQUID MANURE DISPOSAL
FROM CONFINED HOG OPERATIONS 118
35. SUMMARY OF ANIMAL WASTE CHARACTERISTICS 122
36. SIZE OF POSSIBLE TREATMENT UNITS--OXIDATION POND
AND OXIDATION DITCH 123
37. SIZE OF POSSIBLE TREATMENT UNITS--ANAEROBIC
LAGOON AND COMBINED ANAEROBIC-AEROBIC
SYSTEM 127
38. SIZE OF POSSIBLE TREATMENT UNITS--HIGH RATE
ANAEROBIC DIGESTION AND WET OXIDATION 130
39. SIZE OF POSSIBLE TREATMENT UNITS--INCINERATION,
COMPOSTING, AND LAND DISPOSAL 132
iv
-------
Page
40. SIZE OF POSSIBLE TREATMENT UNITS--SUMMARY
COMPARISON 138
41. COST OF POSSIBLE TREATMENT UNITS--SUMMARY
COMPARISON 139
42. COSTS FOR DISPOSAL OF ACTIVATED SLUDGE--
CHICAGO SANITARY DISTRICT
-------
LIST OF FIGURES
Page
1. PER CAPITA CONSUMPTION OF MEAT—1940-1966 ....... 10
2. AGRICULTURAL REGIONS OF THE UNITED STATES 13
3. HOG AND CATTLE INVENTORY IN THE UNITED STATES--
1940-1966 14
4. CHICKEN INVENTORY IN THE UNITED STATES —1940-1966 ... 15
5. NUMBER OF CATTLE ON FEED--1940-1966 18
6. CATTLE FEEDING IN KANSAS--1956-1967 20
7. STATES IN WHICH THE EQUIVALENT POPULATION OF ANIMAL
WASTES IS GREATER THAN THE HUMAN POPULATION (1960) . . 50
8. CATTLE FEEDLOT RUNOFF--NITROGEN, PHOSPHATE, pH . . . . 58
9. CATTLE FEEDLOT RUNOFF—BOD, COD, SOLIDS, AND
VOLATILE ACIDS 59
10. INCOME FROM ANIMAL PRODUCTION OPERATIONS--
CATTLE AND BROILERS 113
11. INCOME FROM ANIMAL PRODUCTION OPERATIONS —
HOGS AND DAIRY 114
12. RECOMMENDED ACTIVITIES FOR ANIMAL WASTE CONTROL
AND ABATEMENT 162
VI
-------
SUMMARY RECOMMENDATIONS
The specific aim of this study was to develop a forward oriented
review of the problem of animal waste control and abatement. The
review attempted to summarize the present body of knowledge, indicate
major problem areas, suggest feasible research and development appli-
cable to the problem, and identify legislative and technical areas
needing further emphasis.
Hopefully, this study will assist in the preparation of
directions and program plans to assure that the pollution control
activities of the nation stay ahead of the problems in this area
rather than attempting to solve them after gross pollution and
damage have occurred.
The recommendations resulting from this study are:
1. That objectives be set with regard to acceptable degrees
of treatment and disposal to control problems that will result
from indiscriminate discard of animal wastes into the environment.
Adequate education, research, development, and training concerning
these problems should be given high priority.
2. That future research and educational activities dealing
with animal wastes develop and emphasize the interrelationships of
animal production operations and waste management operations, such
as waste handling, treatment, and disposal operations, to eliminate
pollution from animal production facilities.
3. That future training activities be separated from research
activities. Training activities should not be the source of the
major research in animal waste control and abatement.
vii
-------
4. That educational and training activities aimed at the
control and abatement of animal waste pollution include: (a) formal
training and education to produce professional people capable of
solving the problem, (b) education of the general public and the
agricultural community to the magnitude and costs of the problem,
(c) opportunities such as senior fellowships at qualified educational
institutions and in governmental organizations to broaden the
background, training, and experience of professionals competent
in only one aspect of animal waste control and abatement, and
(d) workshops at all levels to disseminate information concerning
the problem and proper techniques for its solution.
5. That all projects conducting research on animal waste
control and abatement collect data on the waste characteristics.
Information concerning housing and management practices, rations
fed, and waste handling and collection practices used in the project
also should be reported.
6. That a detailed study be initiated to delineate the proper
analytical techniques to be used for animal wastes. Proper techniques
for accurate determination of waste characteristics, performance
of treatment facilities, and quality of resultant effluents are
needed.
7. That coordinated, interdisciplinary research activities
be initiated to: (a) investigate all possible animal waste
treatment processes, (b) develop new processes for waste handling,
treatment, and disposal, (c) provide information on processes for
viii
-------
both solid, liquid handling and treatment of the wastes, (d) determine
how these processes interact with animal production operations,
(e) provide detailed data on the quality of the solid, liquid, and
gaseous materials, if any, that result from these processes, (f)
itemize the construction, maintenance operations, and personnel
costs associated with the processes, (g) investigate better control
of the wastes at the source, i.e., the animal, and (h) delineate
possible treatment systems that may be used to meet the control
and abatement objectives of a region and/or the nation.
8. That research be conducted on the process effluents
from animal wastes to: (a) determine possible detrimental concen-
trations of materials such as nitrogen, phosphorus, chlorides,
color, and others that could prevent the effluents from being
discharged or reused, (b) develop suitable tertiary processes and
systems to allow the effluents to be discharged or reused, and
(c) determine the possible effect of secondary and tertiary
effluents on receiving surface and ground waters and in possible
reuse systems.
9. That considerable emphasis be given to the assessment
of feasible ultimate disposal techniques for untreated solids and
liquids as well as for the residues from waste treatment processes.
These techniques should be integrated with feasible handling and
treatment processes to develop over-all waste control and abate-
ment systems.
-------
10. That all animal waste research and developmental projects
be oriented to obtain cost data to evaluate potential treatment and
abatement systems. Economic studies should be conducted to evaluate:
(a) the effect of the costs of waste control and abatement on the
costs of animal production, (b) the effect of the costs of animal
production on the costs of waste control and abatement, (c) the
costs that will ultimately be borne by the consumer, and (d) the
need for subsidies.
11. That large scale animal production facilities be considered
as individual industries subject to State and Federal regulations
concerning pollution abatement. Current Federal and State regula-
tions should be reviewed to ensure that they adequately cover
pollution caused by animal production facilities.
12. That a forward oriented review be conducted in five
years to assess the developments in that time and to develop
directions for the future.
-------
PART I
REASONS FOR THE STUDY
The United States continues to experience a dramatic change
in the methods of producing animals for slaughter. Animal production
is changing from small, individual farm operations into large scale
enterprises. Small animals, such as chickens and hogs, are confined
within small areas and buildings in which the environmental conditions
are controlled to produce the greatest weight gain in the shortest
time. There is an increasing trend for cattle to be finished in
similarly controlled areas, dry lot feedlots. Under such conditions,
it is not possible for these animals to drop their wastes on pastures
where the wastes can be absorbed by nature without adversely affect-
ing the environment.
Animal wastes have become a significant problem compounded by
the large volumes to be handled, the nature of the wastes, and
frequently the nearness to metropolitan areas. On a volume basis,
the total animal waste production in the United States exceeds
that produced by the human population by an order of magnitude.
Animal wastes have been shown to be a major source of surface
water pollution and have been implicated in several cases of ground
water pollution. Untreated animal wastes have been involved in the
transmission of animal and human diseases.
Past, and to a large extent, current (1967) water pollution
control activities are directed at domestic and industrial wastes.
1
-------
When pollution from these sources is controlled, wastes from
agricultural operations still may impart considerable pollutional
material to the waters of the nation.
The specific aim of this study has been to develop a forward
oriented review of the animal waste problem and its inherent
pollution potential. The review will attempt to summarize the
present body of knowledge, indicate major problem areas, suggest
feasible research and development applicable to the solution of
the problem, and identify legislative, educational, and technical
areas needing further emphasis. It is hoped that this study will
assist in the preparation of approaches and program plans to assure
that the pollution control activities of the nation stay ahead of
the problems caused by animal wastes rather than attempting to
solve the problems after gross pollution and damage have occurred.
-------
PART 2
INTRODUCTION
In recent years the efficiency of agricultural production has
greatly increased. This increase, however, has generated or has
been associated with a variety of aesthetic and other problems related
to the quality of our environment. Efficiency of animal production
and quality of the environment are obviously and inescapably tied
together. The relationship becomes more pronounced as methods of
livestock production and processing change. An adjustment in one
of the factors can affect and/or constrain possible or desirable
adjustment in the other. Any combination of a given type and scale
of livestock operation and given level of environmental quality will
have its own benefit-cost relationship. It is obvious that a feasible
compromise must be obtained. The concept of a totally unimpaired or
totally polluted environment is not meaningful.
Suburban development and the increase in farm technology have
sharpened the awareness of the problems of animal waste disposal.
With certain animals and in specific areas of the country, large
numbers of animals have been concentrated in relatively small areas.
The cost of collection, storage, treatment, and disposal of animal
wastes in such enterprises may become as important as cost and price
determinants of animal production. Methods of handling the animal
wastes may adversely affect air, water, and soil quality, and offend
the sensitivities of those who dwell nearby.
3
-------
4
Animal wastes are one of at least six sources of farm wastes
whose management and disposal have become one of the most challenging
problems of modern farming. Farm wastes include: (a) human wastes
from the farm population; (b) crop residues, (c) food processing wastes,
(d) dead animals, (e) agricultural chemical residues, and (f) animal
wastes. The problems of animal wastes are related to the handling,
treatment, disposal, and management of these wastes. Animal waste
is a national problem and not the problem of the isolated livestock
producer.
Livestock producers are interested in waste treatment and dis-
posal methods that have low labor requirements, reduce nuisance
conditions, and improve sanitation at minimum cost. At present
the producers are limited by the lack of available technical
information and by the premise that treatment and disposal of
animal waste should involve no extra cost nor should it increase
the cost of the product.
Historically, animal wastes have been recycled through the
soil environment with a minimum of direct release to the water
environment. The change to intensive livestock production
facilities has weakened the complementary relationship between
crop production and livestock production. The relationship is
one in which the grain and roughage produced on the land went
into the livestock production and the manure from the livestock
went back on the land. With increasing concentrations of live-
stock and alternative sources of fertilizers, the practice of
-------
5
distributing the manure on the land has become doubtful from a
profit standpoint. Changes in crop patterns have decreased the
area of land available for manure disposal during the growing
season.
Separation of animal feeding operations from feed production
has caused the disposal of wastes on the land to be less feasible.
A number of intensive livestock production units have been constructed
without sufficient adjacent land on which the manure can be spread.
An increasing number of livestock producers are being faced with
large volumes of wastes that have low value and physical, societal
and/or economic restrictions that limit the feasibility of recycling
animal wastes through the soil environment. One of the largest
problems associated with the confinement production of livestock
involves the waste disposal.
The number of urban oriented rural residents and open
country recreational activities is increasing. This trend, as
well as an increasing desire on the part of the public for a
more sophisticated environment, will continue. These factors
have led to a greater likelihood of problems of agricultural
waste disposal in rural and suburban areas. Public pressures
for improved waste management systems are increasing. New
animal waste collection, transportation, treatment, disposal,
and utilization systems are evolving. At present, neither the
livestock producers nor the engineers can adequately assess the
-------
6
costs or benefits of such systems. Adequate equipment for handling
animal wastes is in the developmental stage. Performance data on
equipment for handling animals'excreta have not been determined (1).
Alternative handling and disposal systems frequently create
additional problems. If the animal wastes are fluidized, the
local water carriage and treatment system is expected to fulfill
an additional function. Concentrating and/or drying increases
equipment and power costs. Aerobic and anaerobic microbial
treatment systems do little to reduce the total volume of material
to be handled. Air pollution results from incineration. Many
systems do not permit reuse or recovery of the nutrients and
energy in the wastes,
In recent years, one of the most positive advances in agri-
culture has been the mechanization and scientific feeding of
livestock. With the market demand for high quality meat, pro-
duction economies assume greater importance. Confinement feeding
of animals has increased significantly in those areas of the
nation having an abundant supply of feed grains. To date many
of the problems associated with disposal of waste from confined
animal feeding have been in corn and grain growing areas of the
Midwest.
Historically, the corn belt of the Midwest has been the
center of hog and cattle feeding. It is possible that the corn
belt will decrease in relative importance as the predominant
-------
7
feeding area as other economic factors assume greater importance
and as livestock production becomes more and more of a manufacturing
operation geared to convert feed into food in the most efficient
fashion.
The livestock industry is undergoing a broad transition with
traditional methods and ideas being replaced by new technology and
knowledge. The geographic location of livestock population may
become less important in the future as feed formulators draw on a
large variety of ingredients to obtain a more economical feed ration.
Low cost labor and proximity to market may become more important
than location of feed grains. This has already been observed with
the broiler and egg production industry in the United States,
If such changes take place in the production of other animals,
livestock production in areas outside the Midwest will increase and
the problems that have been observed with hog and cattle production
facilities in the Midwest will be distributed throughout the nation.
The increasing demand for meat will cause the problems currently
observed in the Midwest to be amplified.
Problems associated with animal waste disposal have existed
for a number of years. Past attempts to solve the problems have
failed because of attempts to use approaches developed for wastes
of other characteristics, to emphasize cheapness rather than ade-
quacy of method, and to consider the problem as separate from other
parts of society. No simple or separate solution is likely to
evolve.
-------
8
A program of waste management, with the economic implications
understood by the consumer and by society, is necessary. The public
must realize that the cost of waste disposal is a part of the price
to be paid for a high standard of living. Better solutions will
emerge when waste management systems are developed that will give
society its desired level of sanitation and society is convinced
of the necessity of paying for it.
-------
PART 3_
TRENDS IN ANIMAL PRODUCTION
Meat Consumption
The animal waste disposal problem is due not only to the
increased population in the United States but also to the increased
consumption of beef and broilers (Figure 1). The 1966 per capita
consumption values are listed in Table 1. The consumption figures
reflect only the usable portion and not the live weight of the
animal. It is estimated that about 425 pounds of meat will
result from a 1000 pound beef animal after removing fat, bone,
and trim. The United States is demonstrating a growing taste for
beef and broilers and a slightly decreased taste for pork. The
per capita consumption of all meats increased about 1570 between
1950-60 while that of beef increased by about 34?0, The consump-
tion of beef has become a larger part of the total meat consumption.
The average population increase in the United States is about 2.5
million people per year. At the 1966 consumption rates, each
additional million people will require another 172,000 beef
cattle, 24,500 dairy cattle, and 433,000 hogs.
Livestock Inventory
The distribution and total numbers of livestock in the United
States are illustrated in Table 2. The North Central region contains
74% of the hogs, 42% of the cattle, and 39% of the poultry. The
South Central and Western regions contain an additional 41% of
the cattle. The poultry population is more evenly divided
9
-------
250,
CO
Q
o
Q.
i
200-
TOTAL
150-
Z)
(O
o
o
Q.
<
O
DC
UJ
CL
100-
BEEF
VEAL, LAMB, TURKEY
1940
1950
960"
1970
FIGURE 1
PER CAPITA CONSUMPTION OF MEAT
1940-1966 (2)
-------
11
TABLE 1
PER CAPITA CONSUMPTION OF MEAT
1966
Item
Beef
Veal
Lamb and Mutton
Pork
Broilers
Turkey
Total
Pounds
103.7
4.6
4,0
58.1
36.0
7.8
214.2
throughout the country, Broiler operations are heavily concen-
trated in the South Central and South Atlantic sections of the
country, The states making up the regions noted are indicated
on Figure 2,
The historical pattern of the hog, cattle, and chicken
inventories is presented in Figures 3 and 4. The fluctuations
in inventory represent adjustment to supply and demand factors.
Throughout the 25-year period shown, the average number of hogs
in the United States has been relatively constant. During the
same period, the number of cattle in the nation has increased by
about 5070 to some 36 million head. An increase of 17 million
head, or about 19%, has occurred over the past eight years.
The number of broilers has increased dramatically in the last
quarter century.
-------
TABLE 2
FARM ANIMAL POPULATION OF THE
UNITED STATES - 1966 (3)
(MILLIONS OF ANIMALS)
Chickens
Region
North Atlantic
East North Central
West North Central
South Atlantic
South Central
Western
Hogs
0.8
15.6
24.4
4,2
5.0
1.1
All
Cattle
4,8
13.7
34.0
7.1
26,7
19.9
Dairy
Cattle
2.8
4.3
3-7
1.4
2.5
1,8
Excluding
Broilers
51.2
48-9
55.6
70.2
78,1
66.2
Broiler!
137-2
51-4
45.2
987.1
1011.3
99.2
United States
51.2
106,6
16.6
371..4
2332.6
-------
KEY
NORTH ATLANTIC
SOUTH ATLANTIC
EAST NORTH
CENTRAL
WEST NORTH
CENTRAL
SOUTH CENTRAL
WESTERN
FIGURE 2
AGRICULTURAL SECTIONS OF THE UNITED STATES
-------
lOOi
(0
z
o
(OUJ
UJI-
UJZ
CD=>
ALL CATTLE
DAIRY CATTLE
1940
1950
I960
1970
FIGURE 3
HOG AND CATTLE INVENTORY
IN THE UNITED STATES - 194(J-136b
-------
ui
x<
01-
(0
LL
OQ
LU
tt|-
UJ
2500i
2000
1500
1000
500
1940
ALL CHICKENS
^^^dBb^^M^^^ ^ a
^^^^^^^^^^^^r^^^^^P>ii^p^^^^
EXCLUDING BROILERS
1950
I960
FIGURE
CHICKEN INVENTORY IN THE
UNITED STATES - 1940-1966 (3)
1970
UI
-------
16
TABLE 3
DISTRIBUTION OF BEEF
PRODUCTION (4)
Region Percent of Total
Beef Production
1959-60 1970
North Central 49,2 48,4
South Central 22,5 22.8
Western 19.3 20.2
South Atlantic 5.5 6.3
North Atlantic 3.5 2.3
Estimates of future beef production suggest that the regional
distribution of beef production will vary only slightly. The
North Central states of Minnesota, Iowa, Missouri, North Dakota,
South Dakota, Nebraska, and Kansas will continue to feed most of
the cattle (Table 3). The number of hogs, cattle, and chickens in
the United States and the world is expected to increase in the
future. In early 1965, the world cattle population was estimated
at 1,084 million head, 2% more than in 1964, and 117=, above the
1956-60 average. The number in North America was 17% above the
1956-60 average with new highs in the United States, Mexico,
Central America, and Canada (5).
Production Units
The trend to confinement feeding of livestock and to increased
numbers of animals per production unit is firmly established in the
United States. The 3.4 billion dollar poultry industry is a leading
-------
17
example of high intensity type of animal production. In the major
poultry producing regions, from 50 to 80% of the laying hens and
most broilers are raised in confinement. Most large poultry
operations are highly mechanized and are able to handle over
100,000 and frequently over 1 million birds per operation.
Offensive conditions produced by poultry operations, particularly
the "cage layer" type, have resulted in serious and seemingly
insoluble situations. The conditions emanate from poultry houses
and manure storage areas, and are created during cleaning, trans-
portation, and spreading of accumulated manure.
Other types of livestock production such as dairy, swine,
and beef operations are facing or will face similar problems.
The cattle industry illustrates the trend toward confinement
feeding of livestock. Specialization has removed cattle from
pastures and grass land and has required confinement of large
numbers in small areas with an average density of one cow per 50
to 100 square feet. Confinement requires that the feed and water
be brought to the animals and they are known as feeder cattle.
The number of cattle on feed for slaughter was over 10
million in 1966 (Figure 5). The rate of increase is large; 66%
in the past eight years and 120% in the past 15 years. Over the
past eight years the number of cattle on feed in the United States
increased at the rate of one-half million head per year. This
rate of increase is not expected to slacken in the near future.
-------
liJ
"
< o
o
o
li. UJ
O l&l
a.
-------
19
Since the 1950's, the commercial cattle feedlot business has
been expanding rapidly. Most of the cattle feedlots in the mid-
western and western states have capacities for more than 1,000 head,
The growth of the industry in Kansas can be used to indicate the
expansion (Figure 6). Commercial feeding operations in Kansas,
i.e., feeding of cattle in large numbers in confined areas as
contrasted to feeding on farms, increased about 1,000% in 10 years.
The increase in the past two years has averaged about 50,000 head
a year. Commercial feedlots were not a factor in Kansas in the
early 1950's. Now they exceed farm cattle feeding in volume.
The amount of cattle on feed can vary throughout the year as
many cattle are put on pasture during the spring and sunnrer months
and on feed during other portions of the year0 The average
commercial feeding period is approximately 120 days. Fluctuations
in the numbers of cattle in commercial feedlots during the year
were less than with farm feeders. Year round cattle feeding
operations have reduced the regular seasonal price changes for
feed cattle (8).
There is a tendency toward establishing beef processing and
packaging facilities in areas near the source*of supply and toward
decentralization of the packing industry. Feed additives and
highly automated feedlot equipment are being used increasingly.
These trends will expand the number of cattle on feedlots and
the number of feedlots in operation.
-------
500
en
h-
o
_i
o
UJ
z cr
-------
21
The number and size of commercial feedlot operations through-
out the nation have increased. Mechanization, improved production
methods, and better nutrition and disease control have enabled
the livestock producers to handle more animals without an increase
in help. The scarcity of inexpensive farm help also has influenced
the trend, A projection of the number of farms in the Pacific
Northwest has shown that, although livestock production is
expected to increase in that region in the future, the number of
feeding operations is expected to decrease (Table 4). The result
will be an increasing number of animals per farm.
Certain types of livestock operations have attained optimum
size consistent with present technology. Others have not. The
downward trend in the number of livestock operations is expected
to continue due to the enlargement of existing units and due to
the uneconomic operations of farms less specialized and unable
to adjust their size. The use of by-product, feeds together with
the availability of concentrate feeds can be expected to encourage
feedlot operations on a larger scale (9).
Studies in California demonstrated an 87% increase in cattle
marketings between 1957 and 1963,, Virtually all che growth was
associated with an increased number of feedlots with 10,000 head
or more capacity (10). The changes in the number of feedlots of
various capacities in recent years are presented in Table 5.
Feedlots of all capacities increased. This trend is expected to
increase in the future. The larger lots also tend to market a
larger percentage of the cattle.
-------
22
TABLE 4
FARM AND LIVESTOCK PROJECTIONS--
PACIFIC NORTHWEST—1960-1985 (9)
Farms (thousands) 1960 1965 1970 1975 1980 1985
Livestock 18.4 17.0 16.0 14.9 14.0 13.2
Poultry 3.8 3.3 2,9 2.6 2.3 2.1
Dairy 15.4 14.2 13.2 12.4 11.6 10.8
Livestock Production (million pounds liveweight)
Cattle and calves 1284 1614 1997 2442 2961 3557
Sheep and lambs 167 163 165 167 167 166
Hogs 154 160 168 178 189 203
Commercial broilers 104 107 119 135 153 172
Turkeys 42 42 42 42 42 42
Other states have experienced an increase in the number and
size of feedlots. In 1956, the commercial lots in Kansas with a
capacity of 1000 head or more numbered only five. In 1965, there
were 65 lots with capacities greater than 1000 head and four lots
with capacities of over 10,000 head.
Summary
The population increase in the nation and the increase in the
per capita consumption of meat will cause greater numbers of animals
to be raised. Because of a growing taste for beef and broilers,
the number of cattle and chickens raised for slaughter will increase
at a rate faster than the population increase. The number of other
livestock raised for slaughter is expected to increase at about the
same rate as the population increase.
-------
23
TABLE 5
NIJMBER AND CAPACITY OF CATTLE FEEDLOTS--
1962-64 (11)
Feedlot Capacity Number of Feedlots
1962 1963 1964
1000 - 1999 752 785 808
2000 - 3999 373 388 421
4000 - 7999 179 215 242
8000 -15,999 105 114 120
16,000 -31,999 26 28 34
32,000+ 5 7 10
For a variety of reasons, the number of commercial livestock
feeding operations will increase in the future as will the numbers
of animals per production unit. It has been predicted that the
regional distribution of livestock production in the future will
vary little from current distributions. The North Central states
will continue to feed the majority of the hogs; the North Central,
South Central, and Western states will continue to feed the majority
of the cattle; the South Central and Atlantic regions will continue
to raise the majority of the broilers; and the other poultry popula-
tions may be fairly well distributed throughout the nation., Livestock
feeding operations will increase throughout the nation.
Because of increased livestock production, increased numbers
of production units, and increased numbers of animals per production
unit, the problems associated with the handling, treatment and disposal
of wastes from these units are just beginning to be realized and will
be magnified in the future.
-------
PART 4
MANURE PRODUCTION
General
Agriculture is the biggest producer of wastes in the
United States. Livestock on American farms produce about 2
billion tons of manure each year. On a wet basis, an estimated
3 pounds of manure are defecated for each quart of milk produced
and from 6 to 25 pounds of manure are produced per pound of
livestock weight gain (12). A portion of the total waste
production remains in the pasture and rangeland, but an
enormous volume accumulates in feedlots and buildings and must
be collected, transported, and disposed of in an economical
and nonoffensive manner. Manure management is one of the
largest problems currently facing the livestock industry.
A review of a large number of publications reveals that
the term "manure" may mean any one of a number of things:
(1) fresh excrement including both the solid and liquid portions,
(2) total excrement but with enough bedding added to absorb the
liquid portion, (3) the remaining part of the total excrement
after most of the liquid has drained away, (4) the remaining
material after liquid drainage, evaporation of water, and
leaching of soluble nutrients, or (5) only the liquid which has
been allowed to drain from the total excrement.
The water content of each of the preceding materials is
highly variable. The moisture content of fresh excrement also
24
-------
25
changes with the type of feed and environmental temperature„
Evaporation of water may occur rapidly under certain conditions.
Water is added from rainwater, washwater, or is added specifically
to increase the flow and pumping characteristics of liquid manure.
Reported data on manure production vary, depending upon the
above factors. Authors frequently do not describe the conditions
under which the samples were collected and animals housed,
Effect of Ration
Housing and management conditions are unique for each species
of animal and are reflected in the amount and nature of wastes
produced. These differences are due to differences in size, diet,
and metabolism (13). Simple stomached animals like swine produce
feces and urine similar to that of humans<, With both swine and
poultry, the diets consumed are highly digestible and the amount
of excreta produced is relatively small compared to other animals„
The manure from herbivores and ruminants, such as cattle and
horses, is different. The bacteria that inhabit the stomach of the
ruminant enable these animals to utilize cellulosic feeds. There
are, however, certain compounds such as lignin which accompany
cellulose in plants and which are difficult to digest in the
rumeno Ruminants tend to produce relatively large amounts of
fecal wastes when compared to the pounds of feed consumed. These
wastes have a different composition than the wastes from simple
stomached species. Urinary wastes from herbivores tend to be more
alkaline because diets are higher in compounds such as potassium,
calcium, and magnesium (13),
-------
26
One must be cautious in assuming that data accumulated with
one species of animal will be applicable to other species. Care
must also be taken in assuming that studies made with human wastes
will apply to the wastes of animals.
Manure from different classes of animals will have different
characteristics. Manure from grass fed animals, growing stock
and milk stock is less rich than that from animals being fattened
or from work animals liberally fed on concentrates (14). Growing
animals and those producing milk retain more nitrogen, phosphorus,
calcium, and digestible components of their food for weight gain
and milk production than is retained by mature stock being fattened.
Animals being fattened are liberally fed to obtain large weight
increases. Less nitrogen and minerals are retained in proportion
to the amount of food consumed.
Animals in confinement are fed feed of a composition to cause
the greatest weight gain in the shortest time. Highly efficient
consumption of the feed by the animal is requisite to continuous
and rapid weight gain by the animal. Wastes produced under these
circumstances will contain more material capable of causing
nuisance and pollutional problems than will waste produced under
conditions where weight gain is less critical. Animals of the same
kind that are fed more concentrates excrete more of the nutritive
material because the food contains more. As an example, as the
level of protein feeding is raised beyond a certain point, the
protein is less effectively digested and more passes into the feces.
-------
27
The composition of animal manure is dependent upon the
digestibility^ the protein and fiber content, and the nature of
elements of the feed ration. Differences in animal manure can
be produced by changes in the environment and by differences in
the level of productivity of the stock. Feed additives such as
antibiotics, copper, arsenic, grit, or sand will also affect the
biochemical properties and the physical characteristics of the
manure. After the manure has been excreted, it can be contaminated
with bedding, waste feed, and can be diluted with water.
The general nature of animal wastes has been described by
Morrison (15):
The feces of farm animals consist chiefly of undigested
food that has never really been within the body proper.
This undigested food is mostly cellulose or fiber, which
has escaped bacterial action. A portion of the other
nutrients usually escape digestion. This may be due to
insufficient chewing of such foods as seeds or because
some nutrients are protected from the digestive juices
through being enclosed in resistant cell walls of cellu-
lose.
In addition to undigested food the feces also contain
residue from the digestive fluids, waste mineral matter,
worn-out cells from the intestinal linings, mucus, and
bacteria. They may also contain such foreign matter as
dirt consumed along with the food.
Nearly all of the nitrogenous waste, resulting from
the breakdown of protein material in the body, is
excreted in the urine through the kidneys, though a
trace is given off in the sweat and a more appreciable
amount in the feces. In mammals this waste chiefly
takes the form of urea, while in birds it is excreted
chiefly as uric acid.
A great variety of other end-products of metabolism
are likewise eliminated by the kidneys through the urine.
Much of the mineral matter is excreted in the urine.
However, calcium, magnesium, iron, and phosphorus are
voided chiefly in the feces. Small amounts of most of
the substances eliminated in the urine are also excreted
by the skin through the sweat glands.
-------
28
Undigested material in the feed and bacterial cells, living
and dead, makes up 20 to 30 percent of the solid excrement and
contain half or more of its nitrogen content (14). The undigested
lignin will combine with the proteins to form a humus comparable
with that of soil. More than 25% of the organic matter in cow
manure is true humus (14).
The urinary secretion of birds is semisolid and is voided
with the feces so that hen manure is a very concentrated product.
The urine of hogs makes up a greater proportion of the total
excrement and is low in nitrogen and high in phosphoric acid.
It is difficult to predict future types of rations that will
be used in animal confinement operations., The controlling factor
will be the availability and cost of the various types of feed.
As an example, rainfall during most of 1967 was adequate in most
states with the exception of a small area of Texas and part of
North Dakota. Reliable crop reports indicate a record corn crop
along with increases in grain sorghum. The prospects for silage
and hay crops are good.
Least cost rations are calculated daily in some of the large
livestock production plants such as large commercial feed yards
and at least seasonally on farms producing large numbers of live-
stock. Sorghum grain, corn, and even wheat enter the least cost
ration picture. This year (1967) protein supplements are priced
in the $90-per-ton range (141). The availability of silage and
roughage as well as the feed grains may preclude the use of
-------
29
concentrated feed supplements. A rule of thumb relating good alfalfa
hay and a good 40% protein supplement is that four pounds of good
alfalfa is the equivalent of one pound of 40% oil meal supplement.
The cost of protein supplements is causing consideration of the
use of urea in rations„ Use of urea in beef finishing rations is
satisfactory up to at least one-third the crude protein source (141).
It is possible to remove all roughage from cattle finishing rations
by eliminating roughage slowly and increasing grain at the rate of
005 pound per head per day (141),
From the waste abatement and control standpoint;, it would be
highly desirable to reduce the quantity of nondigestible material
in the feed. This does not appear to be a controllable factor but
will depend upon the cost and availability of the feed. The cost of
waste abatement and treatment for the animal producer will introduce
another factor that may place greater emphasis on rations with less
roughage and nondigestible material and alter the present concept
of least cost rations.
There is considerable variation in the characteristics of
wastes from confinement feeding operations. These variations occur
because of the items described above, the kind of surface upon which
the manuxe accumulates, and the frequency with which the operation
is cleaned. In addition, data accumulated more than 10 years ago
on the quantity and quality of animal wastes may not represent the
characteristics of current wastes because of the changes in feeding,
housing, and environment. For example3 bedding is rarely used in
-------
30
current confinement feeding operations. The characteristics reported
in subsequent subsections represent data from investigations reported
since 1960 and do not include bedding or litter.
Physical and Chemical Characteristics
Correlation of reported data is difficult because investigators
report information in different units and because not all studies
collect data on all parameters. Physical and chemical characteristics
of animal wastes, as determined by a number of detailed studies, are
listed in Tables 6-11.
Culpin (22) reported that in England the average amount of
undiluted manure slurry that resulted from livestock operations,
in terms of gallons per day, was: 5.1 per head of dairy cattle,
1.6 per fattening pig, and 6.2 per 100 head of poultry. Wolf (23)
indicated that 1 to 2 gallons of manure per hog per day occurred
during the finishing period. Taiganides ejt al. (24) noted that the
daily quantity of hog manure varied with the time of the year (Table 12)
and suggested a value of 5 pounds of manure per 100 pounds live weight
as a daily year round average.
Dale and Day (25) have reported that the daily production of
manure from dairy cattle was 7% of the body weight of the animal.
The manure contained 87.57o moisture, 12.8 pounds of dry matter in
the feces, and 1.08 pounds of dry matter in the urine. Urine made
up 30% of the weight of manure, the rest being feces. Sobel and
Guest (26) stated that a dairy cow excretes 8% of the body weight
-------
31
TABLE 6
ANIMAL WASTE CHARACTERISTICS (16)
Item
Animal size (lb.)
Wet Manure
(Ib./day)
Total Solids
(% wet basis)
Total Solids
(Ib./day)
Volatile Solids
(X dry basis)
Nitrogen
(Ib./day)
P205 (Ib./day)
K 0 (Ib./day)
LIVESTOCK
Parameter
Animal weight (lb.)
Manure Production
(ft3/day)
Manure Density
(lb,/ft3)
Moisture (%)
Nitrogen
Chickens Hogs Ca
4-5 100
0.12-.39 2.8-9.5 38.
25-48 12-28
0.05-.10 0.8-1.6 9.
74-79 83-87
0.0012-.0057 0.042-.060 0.
0.0010-.0045 0.029-.032 0.
0.0005-.0019 0,034-, 062 0,
TABLE 7
WASTE CHARACTERISTICS* (17)
Dairy Beef
Cattle Cattle Poultry
1400 950 5
1.3 1.0 0.0062
62 60 60
85 85 72
3,5 3.1 5.4
ttle
1000
5-74.0
13-27
5-11.4
_
35-. 44
11-. 12
27-. 34
Swine
200
0.28
62
82
3.3
Shee]
100
0.11
65
77
5.4
(7c dry solids)
*fresh mixed manure and urine
-------
32
TABLE 8
POULTRY WASTE CHARACTERISTICS (18)
Parameter
Total Nitrogen
Ammonia Nitrogen (mg/1 N)
Alkalinity (mg/1 CaC03)
pH
P2°5
Fe2°3
so3
CaO
ZnO
Total Solids (%)
Volatile Solids
(% dry solids)
Value*
1.8-5.9
5400
21,000-52,000
6.4-7.0
1.0-6.6
0.8-3.3
1.1
0.4-1.2
4-12
0.4-1.2
0.8
10-50
70-80
*% of Total Solids except as noted
-------
TABLE 9
NUTRIENTS IN ANIMAL WASTES
Parameter
(% of Slurry)
Nitrogen (as N)
Phosphorus (as P)
Potassium (as K)
Parameter
(% Dry Basis)
N
P2o5
Dairy
Cattle
0.13-.42
0.06-.09
0.13~,30
Beef
Cattle
0.24-.60
0,09-. 25
0.14-.28
Hogs
0.3-.9
0.2°=, 6
0,2-. 4
Poultry
0,41-1.7
0,30-1,5
0.13-1,25
Reference
19
19
19
Cattle
0,3 -1.3 0.2 -,9
0.15-0.5 0.14-.83
0,13-0.92 0.18-.52
Horse
Hen
0,9
0,34
1,0
0.66
0,23
0,68
1.8-5,9
1.0-6.6
0,8-3.3
20
20
20
TABLE 10
Animal
Dairy Cattle
Fattening
Cattle
Hog
Horse
Sheep
Per Cent
Moisture
79
80
75
60
65
CHARACTERISTICS OF ANIMAL MANURBS(21)
lb,/Ton Manure
N
11.2
14.0
10,0
13.8
28.0
P_
2,0
4,0
2.8
2,0
4,2
K
10.0
9.0
7,6
12.0
20,0
£
1.0
1.7
2.7
1.4
1.8
Ca
5.6
2.4
11.4
15.7
11.7
Fe_
0.08
0.08
0.56
0.27
0.32
M£
2.2
2.0
1.6
2.8
3.7
Volatile
Solids Fat
322
395
399
386
567
7
9
6
14
-------
34
Animal
Hen
Hog
Cattle
TABLE 11
NUTRIENT'S IN FRESH ANIMAL MANURES
(1W1000 gal) (16)
Ca Mg S Fe
300 24 26 3.9
47 6.6 12 2.3
17 8.7 5.8 0.3
TABLE 12
SEASONAL VARIATION OF HOG MANURE
CHARACTERISTICS (24)
Zn Boron
0.75 0.50
0.50 0.35
0.12 0.12
Cu
0.12
0.13
0.04
Parameter
Mean Air Temp (°F)
Water Consumption
(Ib. day/hog)
Manure Prod.
(Ib. day/100 Ib. hog)
Total Solids (%)
Vol. Solids
(% wet basis)
Winter Summer Summer
1961 1961 1962
53
5,7
15,0
11.1
80
1.1
2.6
18.5
15.5
64
1.3
6.2
15.6
12.9
per day in the form of liquid and solids and that the manure
averages 857. moisture. Sobel (27) indicated that the production
of manure from dairy cattle ranged from 73 to 143 with an average
of 86 pounds per animal per day and contained an average of 87%
moisture.
Sobel (27) also reported that the average waste production
for leghorn chickens ranged from OJ4 to 0.60 and averaged 0.32
pound per animal a day. The moisture content averaged 75%.
-------
35
Perkins et^ al. (28) noted that broiler manure, including floor
litter, contained an average of 2570 moisture, 1.7% nitrogen,
0.81% phosphorus, and 1.25% potassium. I ?r. v.ar.ure average:1 40%
moisture, 1.3% nitrogen, 1.2% phosphorus, and 1.1% potassium.
Papanos and Brown (29) stated that the daily manure of hens raised
in confinement was 0.39 Ib. Benne et_ a 1. (21) estimated that 81%
of the nitrogen, 88% of the phosphoric acid, and 957<, of the
potassium fed to a hen are excreted. Pryor and Connor (30)
indicated that the gross energy value of chicken feces ranged
from 3.2 to 4.5 calories per gram of dry matter and that the
nitrogen content ranged from 0.03 to 0.07 gram of nitrogen per
gram of dry matter depending upon the feed ration.
Studies on the physical composition of fresh poultry manure
have shown that it contained 75 to 80% moisture, 15 to 18% volatile
solids, and 5 to 7% ash. The average particle density was 1.8
o
and the bulk density was about 65 Ih/ft . About 50% of the solids
were finer than 200 mesh. Based upon 75% moisture the manure
contained 1375 B.T.U. per pound of wet manure (27). A white
leghorn laying hen produced about 0.09 pound of dry solids per
day.
A typical daily materials balance on an 800-Ih, beef animal
would indicate the following relationships. An average feed ration
containing 54 Ib. of water and 18.5 Ib. of dry matter would result
in about 2.5 Ib. gain of body weight per day, 34 Ib. of feces, and
14 Ib. of urine. The excreted wastes would contain 11 Ib. dry matter
-------
3;
and 37 Ib. water. The 18.5 lb. of dry matter in the feed would
contain 17.6 lb. of organic matter and minerals including 0.29 lb.
K?0, 0.18 lb. P 0 , and 0.42 lb. N. The manure would contain 10 lb.
of organic matter and minerals including 0.22 lb. K20, 0.14 lb. IV^S
and 0.34 lb. N.
Estimates of manure as percent of body weight suggest that
average values for dairy cattle, beef cattle, hogs, and laying
hens are 8, 6, 6, and 5%, respectively.
Pollutional Characteristics
The previous section attempted to correlate the physical and
chemical characteristics of animal wastes as determined by a number
of investigators. These characteristics have significance in
estimating the quantity and quality of wastes from a variety of
animals. For reasons indicated earlier, the data obtained to
date are not always comparable.
Individuals concerned with pollution control activities are
interested in characteristics that describe the poilutional charac-
teristics, i.e., BOD, COD, suspended solids, and nutrient content
of these wastes. Investigators have used at least three different
ways to report these data.
The poilutional characteristics can be reported in terms of
mg/1 of the liquid slurry that results, Since the water content
of the waste slurry will vary depending on the quantity of water
used in cleaning, spilled by the animals in drinking, excreted by
-------
37
the animals, and by any evaporation or rainfall that occurs between
cleanings, values based on mg/1 can be expected to vary.
Animal wastes differ significantly from conventional municipal
and industrial wastes in that they are solid matter which contains
some water. Although the water content will vary, the solids content
is dependent only upon the ration fed and the animal species and
should be relatively constant per animal. Hence, data frequently
are presented as milligram of total or volatile solids.
Other investigators relate the. quantity of material to the
animal and report data in terms of pounds par head of animal. This
latter approach probably is the most realistic and valuable in
estimating the pollutions! capabilities of a particular production
unit.
Traditional analytical techniques for pollutional characteristics
such as BOD, COD, and suspended solids were developed for use with
liquid wastes. Animal wastes and waste slurries are highly concen-
trated and manifold dilutions must be made before the traditional
techniques can be used. Certain components of the wastes, such as
antibiotics and heavy metals that are fed to ensure adequate growth
and minimum animal loss, can interfere with some of the analytical
techniques. Representative sampling is difficult with wastes as
concentrated and heterogenous as animal wastes.
The factors listed in the paragraphs above, and those listed
earlier in the section on the effects of rations, indicate why
the data from a. number of investigators can be in wide disagreement.
-------
38
The data available from a number of detailed studies are presented
in Tables 13-14. Data on waste slurries from dairy or beef cattle
operations in the United States are not available since the wastes
are generally removed as solid material rather than as a liquid
mixture. Additional characteristics of wastes from beef cattle
are presented in Table 15.
Interest in wastes from animal production operations in
England has increased considerably due to recent legislation
that brought farm effluents into the category of trade effluents.
The range of results obtained in England are shown in Table 16,
Population Equivalents
The difficulties noted above have led a number of investi-
gators to use population equivalents to estimate the relative
contribution of animal wastes. Henderson (45) was one of the
earliest to use this approach. His comparisons are presented in
Table 17. Population equivalent values can be based upon waste
liquid volume, BODc, solids, or nutrient contributions. Population
equivalent values based upon liquid volume have no meaning with
animal wastes due to the variability of liquid volumes from
production units. Population equivalents estimated by a number
of investigators are presented in Table 18. Population equivalent
values are usually based on a contribution of 0.17 Ib BODr/capita/
day and 0.20 Ib suspended solids/capita/day in domestic sewage,
Population equivalent values are most useful in relative comparisons
-------
TABLE 13
POLLUTIONAL CHARACTERISTICS OF ANIMAL WASTES
WEIGHT UNITS
Total** Volatile** BOD
Solids Solids ib.'
lb.A>ay*
Ib.ybay
Day
ib.
Ib
COD
ib.
Ib. VS Day Ib
. VS
BOD
COD
Nitrogen
" Total'"""'" Ammonia 2°5
Ib./day
Ib./day Ib^Day Ref
CHICKENS (4-5 Ibs.)
0.063
0.066
0.035
0.044
0.051
0.
0.
015
015
0.34
0.29
0.
0.
0.
033
050
057
0 93
1.14
1.11
0.30
0.26
0.
0.
0030
0036
0.015-.032
0.057-.084
0.006-.010
0.
015
16
0.0006 0.0026 30
0,0023 31
35
42
47
SWINE (100 Ib.)
0.80
0.97
0.50
0.71
0.62
0.80
0.35
0.
0.
0.
o.
0.
20
43
25
22
56
0.32
0.54
0.30
0.
0.
0,
75
96
47
DAIRY CATTLE
10,4
6.8
7.5
3.62
9
0.16
8.3
5.7
3.17
1.
1.
1.
0.
1.
0.02-
53
53
32
44
02
.04
0.13
0.18
0.23
0.32
0.28
8.
5.
BEEF
3.
4
8
CATTLE
26
DUCKS
1,20
1.20
1.56
(1000
1,57
1.00
1.02
(1000
1.03
1.15
0.27
0.45
0.19
lb.)
0,08
0.18
0.23
Ib.)
0.31
0.40
0.
0.
0.
0.
0.
0.
0.
0.
0.
032
064
07
38
37
49
26
26
08
0.024 0.025 31
24
32
33
35
41
42
33
0.12 31
0.23 34
42
0.11 34
7
0.006-.01*** 36
*lb,/day means Ib./day/animal
**Dry solids
***as PO/
10
-------
TABLE 14
POLLUTIONAL CHARACTERISTICS OF ANIMAL WASTES-
CONCENTRATION UNITS*
Waste
Volume
(Gal/day/
animal)
.05
2.5-5
BOD
(mg/1)
8500-40,000
29,600
13,000
24,000
(3)
8,200
27,000-33,000
2,250
52,000
30,000
1,275-13,260
Sus .
COD Solids
(mg/1) (mg/1)
13,200 8,600
172,000 56,700
70,000-
90,000
4,740
143,000
Total
Solids
(mg/1)
CHICKENS
15,900
180,000
SWINE
6,000-
8,000
695
6,240
Nitrogen (m^/l) PO^
Total" ~" " NH~
~4 mg/1
2,020
7,660
500
5,500-
7,500
410
2,760 4,875
Remarks Ref.
35
37
(1) 38
(2) 38
32
39
(1) 40
(2) 40
41
35
DAIRY CATTLE
9,900
-Concentration of waste slurry or manure from waste production units
(1) little water conservation
(2) minimum water
("3"; antibiotic effect
37
-------
41
TABLE 15
WASTES CHARACTERISTICS OF A 900 LB. STEER (7)
60 Ib. wet manure per day
(43 Ib. feces, 17 Ib. urine)
9 Ib. dry manure per day
85% moisture content
BOD5 - 10,000 to 20,000 mg/kg
(1 to 2 Ib./steer/day)
COD - 80,000 to 130,000 mg/kg
(9 Ib./steer/day)
Volatile Solids - 7 Ib./steer/day
Coliform - 230,000/gm
(6 billion/steer/day)
Fecal Coliform _ Less than Q,Q5
Fecal Strep
of the magnitude of the wastes contributed from domestic and/or
municipal sources and from animal waste sources.
Magnitude of the Problem
As Tables 6-18 show, it is difficult to obtain accurate average
animal waste production values from published data. Average values
are useful to develop order of magnitude information concerning
current and potential animal production units.
The average values listed in Table 19 have been estimated by
the author using the data in Tables 6, 7, and 13 as representative
of animal wastes. These values should be used with an understanding
as to why variations exist in the data, as described in previous
paragraphs. Suspended solids have no relevance to animal wastes
since the latter is a solid rather than a liquid waste. It is
meaningful to discuss the total dry solids content of these wastes.
Thus, to obtain equivalent per capita values, the per capita total
solids contribution of municipal waste water,0.55 Ib. TS/capita/day
(48) was used.
-------
TABLE 16
CHARACTERISTICS OF FARM EFFLUENTS
faste Vol.
gal/animal/
day)
2.6-6.1
5.1-28.3
7.4-9.5
4.4-9.4
18.9
10-30
32
BOD Suspended__Solids
tng/1 lb, /animal mg/1 lb, /animal
day
292-3620 O.Q2-.09
200-2170 0.06-.13
300-1440 0.02-.14
455-2120 0.03-.22
472 0.09
450-4330
1840
610-2000
day
3085-7190 0.18-.19
700-3780 0.11-2.5
220-790 0.02-.07
390-1660 0.02-.16
817 0.17
3090
1490-2380
Nitrogen
Total
mg/1
172-1812
100-1220
130-1202
620-4200
100
1175
Remarks Ref
cowshed
cowshed &
dairy
cowshed &
dairy
milking
parlor
milking
parlor
cowshed
excl. dung
farrowing
house
milking
parlor
42
42
43
42
43
35
43
44
-------
43
TABLE 17
POPULATION EQUIVALENTS OF ANIMAL WASTES
(BOD5 Basis) (45)
Species Human Excrement Domestic Sewage
Baseline Baseline
Man
Cattle
Hen
Sheep
Swine
1.0
6.4
0.32
0.57
1.6
0.55
3.5
0.17
0.31
0.9
Animal wastes rarely contain nitrites and nitrates. Nitrogen
found in these wastes is predominately organic and ammonia nitrogen
and therefore, total Kjeldahl nitrogen can be used as an accurate
measure of the total nitrogen content of these wastes. The nitrogen
contribution of domestic wastes has been estimated as 8 to 12 Ib./cap/yr
(49) (0.033 Ib./cap/day). All forms of nitrogen, i.e., organic, ammonia,
nitrite, and nitrate nitrogen, may contribute to this concentration.
The per capita value of domestic sewage can be related to that of animal
wastes since both measurements refer to the total nitrogen content of
each type of waste.
The variations in pounds per animal per day (Table 19) reflect
the difference in the size of each species of animal and the type of
ration fed. The per capita equivalents are relatively constant for
a given species of animal when based upon three important pollutional
parameters. The greatest correlation generally occurred between nitro-
gen population equivalent values. The data in Table 19 indicate the
-------
TABLE 18
POPULATION EQUIVALENTS* OF ANIMAL WASTES
BOD5 BASIS
Animal Reference
Chickens (4-5 lb.)
11.8 16
11.3 30
12 46
11 47
10-20 18
Swine (100 lb.)
0.6 16
0.33 24
Cattle (1000 lb)
Dairy 0.13 34
Beef 0-17 34
*Equivalent animals per capita, i.e., 11.8 chickens contribute
the BOD equivalent to one person per day.
-------
45
TABLE 19
AVERAGE ANIMAL WASTE CHARACTERISTICS
Ib. /Animal /Day
Specie
Chickens
Swine
Dairy
Cattle
Beef
Cattle
BOD5
0.015
0.30
1.0
1.0
Total
Dry
Solids
0.06
0.90
10
10
Total
Nitrogen
(c)
0.003
0.05
0.40
0.30
Per Capita , . ,, .
I Si 1 ID 1
Equivalent v '
BOD 5
11
0.57
0.13
0.17
Total
Dry
Solids
9.2
0.60
0.055
0.055
Total
Nitrogen
11
0.66
0.08
0.11
(a) based on average characteristics in municipal sewage
0.17 Ib. BOD/capita/day,0.55 Ib. total solid/capita/day, and
0.033 Ib. total nitrogen/capita/day.
(b) number animals equivalent to one person
(c) total Kjeldahl nitrogen
-------
46
contribution of each species. On a BOD,, basis, 11 chickens are the
equivalent of one person; one hog is the equivalent of 1.8 people;
one head of dairy or beef cattle is the equivalent of 7.7 people.
Heavy emphasis is placed upon the control of domestic and
industrial waste sources in the United States. To put the animal
waste problem in proper perspective, Tables 20 and 21 have been
prepared. Table 20 illustrates the human population in the 48
United States, as of the 1960 census, and the population equivalent
of the hogs in each state. The percapita values in Table 19 were
used for this purpose. Seven midwestern states have population
equivalent hog populations greater than the human population of
those states. Similar analyses of all chickens, excluding
broilers, indicated that no state had a population equivalent
chicken population greater than the human population. The
population equivalent cattle population of many states exceeded
the human population of those states.
Table 21 illustrates the equivalent per capita population
of the most important animal species. It is obvious that the
wastes from animals represent a potentially large pollution
problem.
The data used to prepare Tables 20 and 21 were the farm census
figures prepared by the U. S. Department of Agriculture (3). Many
animals included in this census are reared in areas where the
wastes can be absorbed by the land without creating pollutional
-------
47
State
TABLE 20
EQUIVALENT POPULATION* OF ANIMALS (1960)
Human HOGS
Population BOD
3267
1302
1786
L 15717
1754
it 2535
446
4952
4043
668
10081
4662
2758
2179
3038
3257
969
3100
jtts 5149
7822
3414
ji 2178
4320
674
1411
285
lire 608
y 6067
3 951
16783
slina 4556
ata 633
9706
2329
1769
nia 11319
and 859
olina 2382
ota 681
3267
9580
891
390
3967
n 2853
inia 1860
3952
330
Basis
2060
58
860
680
395
38
63
720
3200
270
13500
8900
23400
2120
2650
610
40
335
243
1440
6500
1400
7600
270
4500
18
23
3100
100
240
2730
520
4850
850
330
1000
18
1080
2400
2620
2000
122
20
1240
260
200
3500
63
Total Dry
Solids Basis
1900
52
800
630
370
35
60
670
2950
250
12500
8300
21800
1950
2460
560
36
310
225
1330
6000
1300
7100
250
4140
17
21
2850
93
220
2500
480
4500
790
310
930
17
1000
2200
2400
1860
115
18
1150
240
185
3300
60
Total
Nitrogen
Basis
1720
48
720
565
330
32
52
600
2670
225
11200
7420
19500
1770
2210
510
33
280
202
1200
5400
1160
6350
235
3750
15
19
2580
84
200
2280
435
4050
710
275
835
15
900
2000
2180
1670
102
16
1040
216
165
2940
53
Alabama
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachus<
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hamp
New Jersey
New Mexico
New York
North Ca
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Caroli
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virg
Wisconsin
Wyoming
*In terms of equivalent waste contribution from people, units are in
terms of thousands of people or equivalent people.
-------
48
TABLE 21
EQUIVALENT POPULATION* OF ANIMALS
IN THE UNITED STATES (1960) (MILLIONS)
Human
Population
179.3
Specie
All Cattle
Hogs
Chickens
Broilers
BOD
Basis
655
106
33
163
Total Dry
Solids
Basis
1,600
74
40
195
Total
Nitrogen
Basis
1,040
89
33
163
*In terms of equivalent people
problems. Wastes caused by animals in confinement are likely to
cause the greater pollutional problems. The magnitude of the
potential problem caused by these confinement operations can be
estimated by viewing the statistics of beef feeder cattle and
commercial broiler chickens produced by such operations. Table
22 indicates that the states having a per capita equivalent
population of these animals greater than the human population.
Figure 7 depicts the regions having the greatest potential
for animal waste problems. Broiler operations predominate in
Atlantic and Southern states while hog and beef cattle operations
predominate in the Midwest and Western states. With the popu-
lation increase and the increased per capita consumption of
beef and chicken, confinement operations can be expected to
-------
49
TABLE 22
EQUIVALENT POPULATION OF ANIMAL WASTES GREATER THAN
HUMAN POPULATION (1960)
State Beef Feeder Commercial Broiler
Cattle Chickens
Alabama *
Arizona *
Arkansas *
California
Colorado *
Connecticut
Delaware *
Florida
Georgia *
Idaho *
Illinois *
Indiana
Iowa *
Kansas *
Kentucky
Louisiana
Maine *
Maryland *
Massachusetts
Michigan
Minnesota *
Mississippi *
Missouri *
Montana *
Nebraska *
Nevada *
New Hampshire
New Jersey
New Mexico
New York
North Carolina *
North Dakota *
Ohio *
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota *
Tennessee
Texas *
Utah *
Vermont
Virginia *
Washington
West Virginia *
Wisconsin
Wyoming *
-------
KEY
== BEEF
CATTLE
'////, BROILERS
*Data from Tables 18 and 20
FIGURE 7
STATES IN WHICH THE EQUIVALENT POPULATION OF ANIMAL WASTES
IS GREATER THAN THE HUMAN POPULATION (I960)*
i n
O
-------
51
increase in the states noted in Figure 7 as well as in other states.
Problems associated with other animal wastes will increase in these
states as well.
Summary
Estimating animal manure production is difficult. Published
values vary due to differences in: (1) housing and management
practices, (2) type of rations fed, (3) analytical techniques
employed, and (4) manure handling and collection techniques.
Future investigators dealing with any aspect of the animal waste
problem should be encouraged to report the conditions under which
the animals were fed and housed and the manner in which the samples
were taken and analyzed so that continuing correlation of waste
production can be made.
It is doubtful that any single study on animal waste charac-
teristics would be as valuable as comprehensive information obtained
from a multitude of independent investigations studying a number of
factors under widely varying conditions. It would be valuable to
have a detailed study on the applicability of the traditional
physical, chemical, and biological analytical techniques to animal
wastes. It is unlikely that this information will be included in
conventional animal waste studies. The traditional techniques were
developed for liquid -wastes and their applicability and accuracy
when used with solid wastes, such as animal wastes, remain largely
unknown. New analytical techniques may be needed.
-------
52
The evaluation of animal waste characteristics conducted in
this report is summarized in Table 19. These parameters represent
average values derived from the published data and have greatest
value when used as guides to estimate the potential wastes generated
from a production unit.
The trend toward increasing confinement animal feeding will
create greater concentrations of wastes and should create wastes
of greater pollutional nature as the feed rations slowly change
to feeds that contain less roughage and more biodegradable material.
A number of States have a per capita equivalent animal popu-
lation greater thar. the human population. These are the States
where problems generated by animal wastes will likely be the
greatest, This does not infer that problems will not occur in
other states. Localized problems may occur whenever concentrated
animal production units are developed. As indicated in Table 5,
about half of the beef cattle feedlots have capacities for 2,000
head, and 10,000-head lots are not uncommon. These lots will
produce wastes, on a total solids basis, equivalent to that
from communities of approximately 36,000 and 182,000 population,
respectively. Broiler operations may house from 100,000 to
1,000,000 birds. These operations produce wastes comparable to
communities of approximately 10,000 and 100,000 population,
respectively,
Animal waste production in the United States exceeds that
of human population. The animal wastes have a large pollutional
-------
53
potential. An enthusiastic, vigorous, and concerted effort
to abate and control problems arising from animal production
units is justified*
-------
PART 5
POLLUTION AND NUISANCES
Introduction
A variety of educational activities has created a growing
public awareness that the rivers and streams of the nation should
be made and kept reasonably clean. These programs have emphasized
the control of municipal and industrial pollution sources. The
pollution hazards inherent in the disposal of animal wastes are
less well understood even by the professionals in the agricul-
tural and sanitary engineering fields.
Data describing potential and actual pollution caused by
animal wastes are accumulating. Henderson (45) noted that,
under certain conditions, agricultural land runoff may make munic-
ipal contributions appear insignificant. Based on the evaluation
of only the contribution from cattle, hogs, chickens, and sheep,
it has been postulated that a flushing flow over l?c of the
Missouri River drainage basin would contribute pollution equiva-
lent to that from a population of 2,9 million (51). Discharges
of this type would severely tax the resources of the receiving
stream since they represent a slug load to the stream. More
definitive studies are reported in the following paragraphs,
Organic Pollution
Until the animal wastes enter ground or surface waters,
they rarely represent a serious water pollution problem. Such
wastes usually stay within the confinement area until the area is
-------
55
cleaned or, in some cases, until runoff washes them away. The
water pollution problem associated with animal wastes frequently
is a drainage problem. Runoff from confinement areas and from
land used for disposal of the waste occurs during and following
rainfall.
Farm animal wastes can be a major source of water pollution.
Studies on Long Island have revealed that the navigable waters of
Moriches Bay and part of Great South Bay are polluted by bacteria,
suspended solids, and nutrients that have resulted from land
drainage. Major sources of pollution are the duck farms lining
the shores (36), Closing of these areas to shellfish operations
has caused an economic injury in excess of 2.5 million dollars
annually to the shellfish industry* Pollution of these waters
has resulted in an unsightly appearance, production of objection-
able odors, excessive algae and aquatic plants, and has adversely
affected recreational use of the waters.
Actual documentation of pollution caused by animal wastes
is rare due to the variable nature of rainfall and runoff relation-
ships „ The effect of such pollution is apparent in the number of
fish kills that have occurred. The fish kills attributable to
animal wastes in Kansas and in the netion are presented in Table
23. Most of the fish kills caused by animal wastes occurred in
in Kansas. This suggests a greater awareness by Kansas officials
of the pollution caused by animal wastes and not that the problem
is unique to Kansas. Animal wastes killed 82 and 99.5 percent of
-------
56
TABLE 23
FISH KILLS ATTRIBUTED TO ANIMAL WASTES (52-54)
Number of Kills
1964 1965 1966
Kansas 15 5 15
United States 29 29
Fish Killed* (Thousands)
Kansas 1,100 571 1,000
United States 1,156 617
*By animal wastes
the fish killed in Kansas in 1964 and 1965, respectively. Spring
rains in Kansas in 1967 caused tons of cattle feedlot waste to
enter the receiving streams killing an estimated 300,000 to
500,000 fish.
Many of the fish kills in Kansas have occurred upstream
of completed or contemplated multipurpose reservoirs. Entrapment
of such pollution in these reservoirs raises interesting questions
relative to possible aquatic growths and water quality changes in
reservoirs, recreational use of the waters and shore, effect on
downstream water users, and effect on reservoir operations. In the
spring of 1967, the State Health Director of Kansas issued an
order banning body contact sports in the John Redmond reservoir, a
reservoir that had been the scene of a number of fish kills caused
by runoff from cattle feedlots on tributary rivers.
-------
57
The runoff from cattle feedlots can be potent. Miner e_t ^1. (55)
demonstrated that feedLot runoff is a source of high concentrations
of bacteria normally considered as indices of sanitary quality, and
that the greatest pollutant concentrations were obtained during
warm weather, during periods of low rainfall intensity, and when
the manure had dissolved by water soaking. Ammonia nitrogen
concentrations ranged from 16 to 140 mg/1, suspended solids
concentrations ranged from 1500 to 12,000 mg/1, and COD concen-
trations ranged from 3000 to 11,000 mg/1 in the runoff from their
studies,, Average chloride and phosphate concentrations were 300
and 50 mg/1, respectively, for lots with concrete surfaces. The
authors developed equations to predict the COD and nitrogen con-
tent of feedlot runoff based upon the above factors-
Additional characteristics of cattle feedlot runoff are
presented in Figures 8 and 9, The information in the Figures and
that noted above indicate why large and extensive fish kills have
occurred when cattle feedlot runoff has entered a receiving stream.
Smith and Miner (57) obtained wacer quality measurements on
streams and rivers when cattle feedlot runoff occurred and noted
the slug effect of such runoff (Table 24) They found that feed-
lot runoff and streams polluted with such runoff showed high
ammonia concentrations, and that the ammonia associated with feedlot
pollution tended to be detectable before other parameters appeared.
Considerable lengths of stream and rivers were found to be devoid
of oxygen due to pollution caused by feedlot runoff. The slug
-------
58
40
u.
u.
o
o
o
UJ
Ul
u.
UJ
30-
25
10
2 20
15
CO
u
CO
oc
UJ
tr
<
o
10
COD
TOTAL
SOLIDS
VOLATILE
SOLIDS
BOD.
VOLATILE
ACIDS
40 80 120 160
TIME AFTER RAIN STARTED
(MINUTES)
FIGURE 8
CATTLE FEEDLOT RUNOFF
1.74" RAIN/24 HOURS (56)
200
-------
6-1
59
III
I-
<
I
0.
CO
O
30,
20
SOLUBLE
ORTHOPHOSPHATE
800
- 600-
9
E
z
w 400
o
cc
200^
ORGANIC
AMMONIA
40 80 120 160 200
TIME AFTER RAIN STARTED
(MINUTES)
FIGURE 9
CATTLE FEEDLOT RUNOFF
1.74" RAIN/24 HOURS (56)
-------
7.2
0.8
5.9
6.8
4.2
6.2
8
90
22
5
7
3
37
283
63
40
43
22
19
50
35
31
26
25
12.
5.3
0.4'
0.0
0.0
60
TABLE 24
FOX CREEK NEAR STRONG CITY, KANSAS, NOVEMBER 1962
WATER QUALITY PARAMETERS (mg/1) (57)
TIME DO BOD5 COD Cl NH3
Avg. Dry Weather 8.4 2 29 11 0.06
After Rainfall
13 hours
20 hours
26 hours
46 hours
69 hours
117 hours
effect of such runoff provides little warning to downstream users
and traps game fish in the polluted waters.
Where animals are housed in the open, such as cattle feedlots
and duck farms, runoff has caused significant pollution. Pollution
caused by runoff is reduced when the animals are completely housed
as is the case in most hog, broiler and dairy operations. In the
latter cases, pollution has been the result of accidental or willful
disposal of the accumulated wastes in adjacent bodies of water.
Complete confinement will reduce the runoff pollution caused
problems.
Inorganic Pollution
High nitrogen concentrations in ground and surface waters are
another pollution problem associated with confinement animal oper-
ations and feedlot runoff. Keller and Smith (58) indicated that
-------
61
30 to 50% of the rural water supply samples they studied in Missouri
contained more than 5 ppm nitrate-nitrogen, a concentration high
enough to be considered important to livestock production. They
indicated that the main contaminating source both in distribution
and concentration was waste matter at sites of animal habitation.
Soil containing 2000lb. of nitrate-nitrogen per acre was found
below feedlots. Standard surface soils contained about 50 to
150 lb. nitrate-nitrogen per acre. They noted that contamination
from nitrates remained even after an area was abandoned from
animal use. Barnyards, feedlots, and manure piles have been
indicated as sources of excessive nitrate nitrogen in shallow
wells in Nebraska and Illinois (58,60).
The high concentrations of ammonia nitrogen in feedlot runoff
(55,57) and lagoon effluent (61) contribute to the nitrate concen-
tration in surface waters when the ammonia is oxidized. In addition,
the high nitrogen concentrations contribute to the algal growth
potential in the receiving waters. Nitrogen in water can be a
problem due to the toxicity of nitrates to babies and livestock
and due to the stimulation of aquatic plants in receiving waters.
The nitrogen and phosphorus contribution from various sources
(49) has recently been estimated and is presented in Table 25. The
annual contributions indicate the relative magnitude of the various
waste sources and indicate that domestic and industrial wastes are
not the leading contributors of nitrogen and phosphorus. Equal if
not more attention should be given to problems from agricultural
runoff and animal wastes.
-------
62
TABLE 25
ESTIMATE OF NUTRIENT CONTRIBUTION
FROM VARIOUS SOURCES (49)
Source Nitrogen Phosphorus
106 Ib./yr 106 Ib./yr
Domestic Waste 1100-1600 200-500
Industrial Waste 1000
Rural Runoff
Agricultural land 1500-15,000 120-1200
Non-agricultural land 400-1900 150-170
Farm Animal Waste 1000
Urban Runoff 110-1100 11-170
Rainfall _30'5^0 3"9
The nitrogen contribution from farm animals can be estimated
from the data in Tables 2 and 19. The nitrogen content of the
waste from hogs, all cattle, and chickens including broilers in
1966 was 2.5, 37 and 8 million pounds per day. The total contri-
bution from the above animals is approximately 17,300 million
pounds a year. Not all of this quantity reaches the receiving
waters.
Average chloride concentrations from cattle waste installa-
tions have ranged from 30 to 2500 mg/1 (55,56). The lower
concentrations were associated with runoff while the higher
concentrations were associated with effluents from animal waste
treatment facilities. The average salt intake for cattle ranges
from 1 to 2.5 lb. per month depending on season and type of feed.
The salt content of an average cattle ration is about 1 to 2 lb./
day (15). Most of the salt intake is excreted in the urine and
-------
63
feces. With the average head of cattle excreting about 60 Ib. of
urine and manure per day, the chloride content of liquid slurries
and effluents from waste treatment facilities can be high.
Health Aspects
The list of infectious disease organisms common to man and
other animals is lengthy, including a number that can be water
borne (62), When drainage or runoff from animal production
units reaches a water course, a potential chain for the spread
of disease has been initiated. Although documentation of water
borne disease transmission from animal to man is rare, such
transmission has been noted. Several young people swimming in
the Cedar River, Iowa, were infected with leptospirosis while
swimming downstream from an area where leptospirosis infected
cattle had access to the river *63).
Salmonella organisms have been isolated from fecal specimens,
runoff from animal confinement operations, carcasses of dead
animals, and from waterholes from which the animals drank
(36, 64-67) Iwo organisms, S. dublin and S_. typhimurium were
the salmonella organisms most commonly found in the cattle and
contaminated water investigated, J3. dublin is essentially a
pathogen of cattle but can cause meningitis and septicaemia in
humans. Apparently children are more susceptible than adults,
S.- typhimurium can infect practically all species of birds,
animals, and man with equal facility,.
-------
64
Many infections of farm livestock are spread in their excreta.
The disease potential inherent in the use of manure slurry systems
to dispose of wastes on farm land is unknown. It is possible that
under certain circumstances, the use of such systems could increase
the disease hazard to man and animals. The possible presence of
animal pathogens in runoff and effluent from waste treatment systems
suggests that caution be exercised in reusing such water in and
around animal production units.
Coliform organisms are used as an index of water-borne
disease hazard. The per capita coliform output for cows, hogs,
sheep, and ducks ranged from 2.9 to 9.3 times that of man (68).
Fecal coliform organisms are more indicative of pollution from
humans and animals. Fecal streptococci have also been suggested
as a reliable and definitive measure of human or animal pollution.
The coliform concentration in the effluent from duck holding
facilities has ranged from 6 to 60 million per 100 ml (36).
Enterococci counts of bovine manure have ranged from 3.5 to
17 million per gram while coliform counts have ranged from
0.3 to 0.6 million per gram (34). The total coliform, fecal
coliform, and fecal streptococus counts in cattle feedlot runoff
averaged 105, 72, and 324 million organisms per 100 ml, respectively,
for concrete surfaced lots (55). Total coliform and enterococci
counts in the supernatant from hog waste treatment lagoons averaged
1.4 and 1.2 million organisms per 100 ml, respectively (32).
-------
65
The ratio of fecal coliform to fecal streptococci can be
used to delineate between human and animal pollution. The ratio
in human and domestic wastes has been shown to be over 4 while
for fecal material from animals, the ratio was less than 0.6
(69). A ratio of 0,2 has been noted in cattle feedl.n: runoff (55).
The bacterial types found in a lagoon treating bovine wastes
have led one group of investigators to conclude that the pollu-
tional potential for true E, golj. and £. faecalis in lagoon waters
is minor (34).
Histoplasmosis is a disease caused by a fungus that thrives
in collected bird droppings, The symptoms are similar to those
for influenza and pneumonia. Although most of the patients
recover, deaths can occur. Dust generated by cleaning will
disperse the fungus. Frequent waste removal, and keeping the
wastes wet will minimize the transmission potential. The disease
has not been shown to be a problem with wastes from animals other
than birds.
Additional Problems
Flies can be a nuisance in and around animal production and
waste treatment facilities, Harr et al, 5,70) found that flies were
attracted to freshly excreted waste if the moisture content ranged
from 55 to 85%. Flies were found to accumulate at feeding areas.
Fly production was controlled by covering manure piles with 3 to
4 inches of dried manure or with a plastic tarpaulin Effective
fly control was obtained by spreading the fresh manure in one inch
layers and stirring daily with a rotary tiller0
-------
66
Odors are another nuisance associated with animal production
facilities. While some odors are inevitable near such facilities,
obnoxious odors can be controlled by proper sanitation in the
production facilities and by proper operation of treatment
facilities.
Wastes from animal production waste treatment facilities
are colored. The color is similar to that of medium to strong
tea (7,20,71). The yellow to brown color of the wastes appears
to be unaffected by biological treatment. An effluent with this
characteristic may be aesthetically undesirable and, depending upon
the amount of dilution in the receiving stream, may cause color
problems for downstream water users.
The color apparently is caused by chemicals in true solution
since it cannot be removed by filtration through a membrane filter
with a pore diameter of 0.45 micron. The materials responsible
for color in waters and waste waters are a heterogeneous mixture
of organic compounds yielding fulvic, homic, and hymatomelanic
acid as well as hestianic acid (72,73). Such compounds are part
of the humus found in soil and result from the decay of organic
material. The presence of similar colored material in animal
waste systems is not unexpected in light of the humus formation
within the animal, as previously discussed, and possibly within
the anaerobic and aerobic systems used for waste treatment.
-------
67
Summary
Pollution caused by animal production facilities can be as
detrimental to a receiving water body as wastes from any other
industry. Production facilities and confinement feeding have
been developed with little planning and concern for the nuisance
and pollutional characteristics inherent in the facilities. Many
of the most obvious cases of pollution could have been prevented
if the facilities were located in areas less susceptible to runoff
and to accidental release of wastes directly to receiving streams.
The economics of pollution and nuisance control in animal produc-
tion is an important factor and may mean the difference between
success and failure for the facility.
Information is lacking on the pollution potential inherent
in the spreading of wastes on land, Both ground and surface
water contamination can result as the soluble components, such
as nitrates and chlorides, are leached into the ground and as
runoff moves a variety of potential pollutants overland. Past
emphasis has been upon recovery of the nutrient value of animal
wastes by returning them to the landa Additional information
is needed relating to the maximum quantity of waste that can
be put upon the soil without causing problems. Seasonal, soil,
and crop variations will influence the results.
Methods to minimize the nutrient contribution of animal waste
treatment facilities need investigation. Available information
-------
68
is inadequate to assess the desease hazard in reuse of water from
waste treatment facilities and confinement feeding operations, and
from land disposal of the solid and liquid wastes. The color of
the liquid fraction from confinement and treatment facilities could
be detrimental to discharge and water reuse and deserves further
consideration.
-------
PART 6
WASTE TREATMENT AND DISPOSAL
Introduction
Investigations have shown that animal wastes are amenable to
most processes currently used for domestic and industrial waste
treatment. In discussing feasible treatment and disposal methods,
it is important to realize the differences between animal wastes
and municipal sewage. Sewage is water which contains some solid
matter. Animal wastes are essentially solid material which contain
some water. Although runoff may dilute animal wastes, the concen-
tration of pollutants in the runoff is a number of orders of magnitude
more potent than in domestic sewage (Figures 8 and 9). Animal wastes
usually contain more inert material, such as feed residue and undigest-
ible material, than does municipal sewage.
Processes used for the treatment and disposal of municipal wastes
have been applied to animal wastes and usually have been unsuccessful
because of a lack of understanding of the characteristics of the
wastes, the magnitude of the problem, and economic constraints
currently imposed by society. Hart (74) has estimated that if
conventional waste treatment processes are used, a dairyman would
pay about $200 per cow per year for waste treatment. Morris (19)
indicated that commercial sewage treatment plants would run about
$75 to $125 capital cost per pound of BOD in the livestock manure.
While it is inevitable that the animal production manager, and hence
the public, will have to pay for animal waste treatment and disposal,
69
-------
70
the above costs are unrealistic when applied to animal production
facilities. Taiganides (75) discussed high rate digestion, using
equipment and procedures employed in the digestion of sewage sludges,
noted the high initial cost and potential operating problems, and
forecast its lack of applicability to animal wastes.
Current interest in treatment and disposal of animal wastes
centers on controlled aerobic and anaerobic biological methods
and spreading of the wastes on the land. Some work has been done
on incineration, dehydration, and composting of the wastes. Emphasis
has been placed on processes and systems that are inexpensive and
can be maintained and operated by individuals whose interest in
waste treatment is minor.
Anaerobic Digestion
The high solids content and high oxygen demand of animal
wastes indicate that anaerobic biological systems can be successful.
Anaerobic digestion of animal wastes under controlled conditions
has been successful in both laboratory and field.
Laboratory investigations with beef cattle wastes have
demonstrated that loading rates from 0.1 to 0.4 pound of total
solids per cubic feet per day have been successful (7). Analysis
of data from that study indicated that even higher loading rates
could have been feasible. Other investigations on the anaerobic
digestion of beef cattle manure have demonstrated that between 8
3
and 9 ft of gas/lb. volatile solids (VS) added can be expected
-------
71
from digestion systems treating these wastes (33,37). Similar
O
studies with dairy cow and sheep manure indicated only 2,5 to 3 ft
of gas/lb0VS added could be expected '33). The low values that
occurred with the cow and sheep manure undoubtedly were due to the
fact that not all of the volatile solids in these manures were
biodegradable, again demonstrating that the waste characteristics
are influenced by the type of food ration and type of animal. The
gas produced from digestion of animal wastes generally contains
between 50 to 70% methane depending upon the environmental conditions.
Carbon dioxide is the other major component of the gas,
Hart (37) digested chicken and dairy manure at rates from 0.17
to 0031 and 0,13 to 0,22 Ib, VS/ft /day, respectively, and concluded
that both manures can be stabilized with controlled digestion. With
dairy manure only about 10 to 15% of the volatile solids were destroyed.
About 50% of the volatile solids in the chicken manure were destroyed.
Cassell and Anthonisen (18) digested chicken manure at a rate of
3
0.088 Ib. VS/ft /day and noted that the ammonia nitrogen concentration
in their digesters reached toxic levels which have been reported to
be between 1200 and 2000 icg/1. Trey suggested that the loading be
kept low to avoid the problem of toxic aiwnonia concentrations, The
addition of sodium chloride to a digester with high ammonia nitrogen
concentrations appeared to promote the digestion of chicken manure.
Ammonia toxicity rarely has been a problem with municipal sewage
sludge digestion but could be significant in the high rate digestion
of concentrated solids with a high nitrogen content, such as animal
and especially chicken wastes„
-------
72
Controlled conditions were found necessary for the active
digestion of duck wastes. Otherwise, the volatile acids concen-
tration increased to the point that bacterial metabolism ceased.
O
Continuous loading rates as high as 0.15 Ib. VS/ft /day were
successful (76).
Heated septic tanks have been advocated for the wastes from
caged layer and dairy operations (77,78). A hydraulic cleaning
system and unheated septic tank with effluent recycle were used
for chicken waste disposal (78). The recycled effluent became
concentrated and after four months averaged 0.39% nitrogen, 0.027%
phosphoric acid, and 0.18% soluble potash. The effluent was dis-
posed of on woodland areas and the sludge was returned to the
soil on a batch basis.
Ludington (79) digested chicken manure, and noted the
following reductions: volatile solids, 43%, total solids 33%,
and total weight, 1.5%. He concluded that there was little
advantage to digestion as a method of reducing the total volume
or weight of material to be handled. However the biodegradable
fraction was reduced.
The majority of the laboratory studies digesting animal
wastes have been conducted at 35°C, a temperature unlikely to
be reached in practice. Temperature affects the performance of
a biological system since it affects the activity of microorganisms.
Microorganisms are less active at lower temperatures and a larger
number are needed to produce satisfactory results. Because sludge
-------
73
recycle rarely will be incorporated in animal waste digestion
systems, opportunities to compensate for low temperatures by
increasing the solids held in the system are few.
Field anaerobic systems can effectively handle animal waste
during most of the year but can be upset during cold weather when
the organisms are few and comparatively inactive (52> Low tempera-
tures have been responsible for the failure of anaerobic units in
5outh Dakota where the temperature on the bottom of the unit never
exceeded 15°C throughout the year (80).
^aboratory units usually are well if not completely mixed,
thus promoting optimum contact of the waste and the microorganisms.
This condition is unlikely in field operations. The optimum
quantity of mixing in any anaerobic system has yet to be adequately
evaluated,
The characteristics of laboratory digestion units treating
animal wastes are listed in Table 26, Although controlled
anaerobic digestion can be successful, the effluent from such
units generally will require further treatment before discharge
to the environment.
Aerobic
Aerobic treatment of wastes is feasible when the treatment
process is not limited by the rate of oxygen transfer into solu-
tion. Both laboratory and field studies have demonstrated that
animal waste slurries, effluents from anaerobic systems, and runoff
from confinement operations can be treated aerobically.
-------
TABLE 26
CHARACTERISTICS OF MIXED LIQUOR--ANAEROBIC DIGESTION OF ANIMAL WASTES
Beef Cattle
Waste
Loading Rate
. VS/£t3/day)
PH
Volatile Acids (mg/1)
Volatile Solids (%)
BOD
Chicken Manure Dairy Manure Manure
0.173 0.305 0.122 0.215 0.18 0.08
7.0 6.7
180 100
84 78
7600 19,000 1100 2300 - 1800
52
0.16
6.8
100
80
3300
57
Hog Waste
0.15 0.17
7.4 7.4
190 500
55 71
4P «•
.
5
BOD5 reduction (%)
COD (mg/1) 31,000 70,000 36,300 13,500 - 11,700 22,000
COD reduction (%) - 24 28
Reference 37 37 37 37 33 7 7 33 33
-------
75
Jeffrey e_t al. (33) conducted aeration studies on hog wastes
and noted that the BOD of hog manure can be reduced by 50 to 75%
and 70 to 90%, respectively, in systems with detention times from
6 to 12 days. Better results were obtained with longer detention
times. With continuously fed systems, loadings approaching 10
grams of dry solids per liter provided the most efficient BOD
reduction while a loading of 3 grams of dry solids per liter
provided the better quality effluent, One thousand cubic feet
of air per cubic foot of aerator capacity per day was needed at
the high loading. They also noted that criteria for aeration of
domestic sewage were net directly applicable to the aeration of
hog manure,
Irgens and Day (40) asrated hog waste that had accumulated
beneath a slotted floor hog finishing house. They estimated that
6 cubic fee.t was required to dilute the waste from a 150 Ib. hog
2
to have the aerobic process feasible. About 2,500 ft of air was
needed per pound of BOD. Their laboratory studies indicated that
the treated effluent had a BOD of 10 to 15 mg/1 and contained a
trace of ammonia. A detention time of 20 days was thought
satisfactory.
Dale and Day (25) aerated various concentrations, from 0.5
to 4%, of dairy cattle manure and noted about a 50% reduction in
volatile solids in 18 weeks, The rate of volatile solids reduction
decreased as the solids concentration increased.
-------
76
Loehr and Agnew (7) demonstrated that the effluent from an
anaerobic unit treating beef cattle wastes could be treated
aerobically. The soluble fraction from such aerobic treatment
contained 100 mg/1 BOD5, 600 to 1000 mg/1 COD, and 50 to 75 mg/1
Kjeldahl nitrogen. The data on the soluble fraction indicated
the effluent quality that could be expected if all of the solids
were removed. A solids removal system would be needed in the
aeration system. If the aerobic systems have a long detention
time, solids sepration may not be necessary due to the low oxygen
demand of the solids that would leave as part of the wasted mixed
liquor.
Al-Timimi e_t al. (81) investigated the effect of heat and
aeration on solids accumulation in aerobic units treating
chicken manure. They concluded that the percent dry matter
increase over 20 weeks was 1.5% for the control, 1.33% for aeration,
1.7% for heating (96°F), and 1.2% for aeration plug heating. Aera-
o
tion was at the rate of 57 ml/min/ft of aeration capacity.
A theoretical analysis of chicken manure (79) showed that
44 Ib. of wet manure, the equivalent of 1 Ib. BODc, would result
in 8.8 Ib. dry matter, 5.7 Ib. volatile solids, 4.9 Ib. non-
biodegradable matter, 0.8 Ib. biodegradable matter, 0.7 Ib.
synthesized bacteria and after aerobic digestion, 0.17 Ib.
bacterial dry matter. Even after adequate treatment of the manure
to remove the oxygen demanding components, about 8.2 Ib. or 93%
of the original dry matter remained. A significant solids handling
-------
77
problem still remains after satisfactory destruction of the biodegrad-
able material. Analyses with other animal wastes yield similar
conclusions.
The past two decades have seen considerable investigation and
use of aerobic oxidation ponds or lagoons for waste treatment.
These units are shallow with z. large surface area necessary to
maintain aerobic conditions. It is generally recognized that the
term aerobic does not completely describe the biochemical reactions
taking place in the pond or lagcon. While ample dissolved oxygen
may exist and hence aerobic biochemical reactions take place in the
upper liquid portion of the lagoon, there may be little or no
dissolved oxygen in the lower liquid layers. The settled solids
layer on the bottom of the ?.agoon is devoid of oxygen and anaerobic
conditions prevail. In general, however, the aerobic oxidation
ponds are so designed and loaded that the facultative and anaerobic
conditions have little noticeable effect or> the quality of the pond
effluent. The effluent normally contains considerable dissolved
oxygen and may be supersaturated during daylight hours.
The traditional oxidation pond depends upon the oxygen pro-
duced by algae and the oxygen transferred to the pond by natural
reaeration and wind turbulence to maintain aerobic conditions.
Design criteria for these ponds range from 30 to 50 pounds of BOD
per acre per day depending upon location, The high oxygen demand
associated with animal wastes (Table 13) requires extremely large
surface areas and volumes. For example, a confinement unit holding
-------
78
1000 head of beef cattle would require an oxidation pond of at least
20 acres; a unit holding 1000 hogs would need a pond of at least 5
acres. The following surface areas have been suggested (96) as
minimal for aerobic lagoons treating animal wastes; 50 dairy cows,
general dairy operation—8000 sq. ft.; 1000 laying hens—8000 sq. ft.;
100 hogs—64,000 sq. ft.
Adequate land areas for traditional aerobic oxidation ponds may
be available when confinement feeding is a large distance from urban
areas. There is, however, a strong trend to develop confinement
feeding operations near communities. Land costs increase and odors
and other nuisance conditions will not be tolerated.
Aerobic systems using mechanical or diffused aeration systems
have been employed to reduce the quantity of land needed for aero-
bic treatment. Converse e£ al^ (82) used a submerged diffused air
2
system to aerate a lagoon, 6500 ft , treating hog wastes. Sedimen-
tation units preceded the lagoon. Settled solids were removed to
the fields while the overflow liquid went to the lagoon. An air
rate of 35 cfm produced satisfactory results. Average values of
the lagoon effluent were: BOD 60 mg/1, COD 440 mg/1, ammonia 40
mg/1, nitrates 3 mg/1, and dissolved oxygen 2*3 mg/1.
The oxidation or Pasveer ditch has attracted considerable
attention as a feasible method for maintaining adequate aerobic
conditions with relatively small land areas. The attraction has
resulted due to the possible low cost of the process and the
minimum attention that is needed, Morris (19) has estimated that
-------
79
oxidation ditch costs may be about one-tenth those of commercial
sewage treatment plants.
Linn (83) discussed the use of the oxidation ditch for livestock
manure and suggested that the minimum ditch volume needed per animal
3 3
might be 7 ft per hog, 50 ft per head of dairy or beef cattle, and
o
1 ft per chicken. He also estimated that for a ditch operating as
a continuous unit, the daily addition of manure should not be more
than 1.57o of the ditch volume. He indicated that 5 pounds of
oxygen can be added to the ditch per net horsepower applied to
the paddle wheel and suggested 1 foot of paddle per 400 cubic
feet of ditch.
Forsyth (84) noted that 90 to 95?0 BOD removals were obtained
with oxidation ditches. He indicated that the necessary ditch
•a
capacity per cow and hog were about 95 and 35 ft , respectively,
and that a liquid volume of 8000 to 10,000 gallons per foot of
rotor length was satisfactory. A velocity of at least one foot
per second should be maintained to keep solids from settling.
He reported that a semicontinuous operation in which a cycle of
mixing for four hours followed by 45- minutes for settling and
15 minutes for influent addition and supernatant displacement
was satisfactory. There are many modifications to the traditional
oxidation ditch: continuous, semicontinuous, batch, and the use
of side ditches to act as settling units.
Morris (85) indicated that there were 12 oxidation ditches
treating livestock manure in the United States as of 1967. The
-------
80
use of oxidation ditches in the United States seemed to be mainly
for odor control within the confinement housing. None of the
ditches were designed to produce an effluent that could be
deposited safely in surface waters. Morris described the ditches
currently in use and summarized their effluent quality. BOD
reductions of above 90% have been achieved. The majority of
the BOD in the ditches was associated with the oxygen demand of
the solids.
Solids separation can be used to produce an effluent having
a BODc of 10 to 20 mg/1. All mineral salts in the manure are
retained in the system. The high mineral content and color of
the effluent may make its discharge to a stream undesirable.
Excessive foaming has been reported with a number of ditches
treating livestock manures (39,41,85). Foaming may occur until
adequate microbial solids are built up in the system. The foam
can be controlled with antifoam agents during critical periods.
If insufficient oxygen is added to the system, the ditch may
foam and produce obnoxious odors. With adequate dissolved
oxygen and solids there should be no foam or odors.
Data delineating the effect of temperature on the efficiency
of the units, power requirements, costs involved, and desirable
loading conditions are not available. Controlled field studies
to obtain these are needed.
-------
81
Anaerobic Lagoons
Anaerobic lagoons are units that are organically loaded such
that surface reaeration and potential photosynthetic activity are
unable to maintain aerobic conditions. Many lagoons currently
labeled as anaerobic may be overloaded aerobic lagoons. The true
anaerobic lagoon bears only a superficial resemblance to aerobic
lagoons, has a different purpose, and should be designed on a
different basis than aerobic lagoons.
Anaerobic lagoons offer considerable potential for handling
and treating concentrated animal waste with its high solid and
low water content. Anaerobic lagoons can be used as a controlled
biological unit, as a holding unit prior to land disposal, to
control runoff from confinement areas, or any combination thereof.
In general, the purpose of anaerobic lagoons is the removal,
destruction, and stabilization of organic matter and not water
purification. They can and are used as primary sedimentation
units to reduce the load on subsequent treatment units. They
differ from primary sedimentation units in that the settled
solids are not routinely removed but are left in the unit to
degrade. Solids will gradually build up, the rate depending
on the solids loading rate as well as the rate of solids stabil-
ization. Periodic solids removal will be necessary.
While held in the lagoon, the biodegradable fraction of
the solids will undergo anaerobic decomposition. Considerable
gas may be evolved with a resultant decrease in BOD and COD of
the lagoon contents.
-------
82
Anaerobic lagoons may also function as liquid or solids holding
units where surge capacity is needed. They have been particularly
useful for holding animal wastes prior to field spreading.
There is no need for a large surface area to promote surface
reaeration and to obtain adequate light energy for photosynthesis.
Anaerobic lagoons require less land area than do aerobic lagoons
since they are more heavily loaded. The depth of the lagoon is
not restricted by light penetration. Anaerobic lagoons should be
built with a small surface area and as deep as possible consistent
with construction factors and ground water conditions. The small
surface area promotes anaerobic conditions and decreases the needed
land area. Long liquid detention times are not required. Liquid
detention times as short as three to five days have been success-
ful (86,87).
In anaerobic lagoons, there is a relatively solids free liquid
layer above a layer of settled solids. A floating scum layer usually
will occur depending upon the type of waste. With a small surface
area, the scum can form an effective floating cover to minimize
surface reaeration and to provide some insulation for the lagoon
contents during cold weather.
The actual depth of the lagoon will be restricted by the
existing temperatures. The lagoon temperature may decrease with
depth and may reach a point where biological reactions in the
settled solids are inhibited.
-------
83
The volume of the lagoon will be dictated by the organic
loading rate which will be influenced by the desired frequency
of solids removal. Capacity should be provided to hold the
unmetabolized solids between times of solids removal.
Anaerobic lagoons are comparable to single-stage unmixed,
unheated digesters.. Loading values should be based on pounds
per volume per time as is done for other digestion systems.
O
Loadings of from 0.36 to 10.4 Ib. VS/day/1000 ft have been
reported for lagoons treating a variety of wastes (30,31,32).
However, the advantage of anaerobic lagoons lies with wastes
that are highly concentrated and high loading rates, 132 to
320 Ib. VS/day/1000 ft3, can be used successfully (7,33,37).
Inadequacies and failures of anaerobic lagoons at a variety
of laoding rates have been reported. The establishment and main-
tenance of conditions suitable for optimum digestion play a larger
role in the success or failure of the anaerobic lagoons than does
the loading rate. Alkalinity, pH, temperature, and mixing must
be controlled.
Unbalanced conditions frequently occur during the start-up
of an anaerobic lagoon and when environmental factors abruptly
change, such as when the excess solids are removed from the lagoon
or when the lagoon contents warm up in the spring. The microbial
population will decrease during the winter and an adequate popu-
lation of methane formers may not be present to metabolize the
acids as they are generated in the spring. When excess solids
-------
84
are removed from an anaerobic lagoon, or when an anaerobic lagoon
is being placed in operation, the population of methane bacteria
may be unable to convert the acids as rapidly as they are formed.
Under these conditions, it is important to control the environment
in the lagoon until equilibrium becomes established.
Since digestion will not be inhibited if adequate alkalinity
is present, additional alkalinity can be added to the lagoon until
an optimum environment for digestion is created. Lime is commonly
used for this purpose although other chemicals such as sodium
bicarbonate, ammonium carbonate, and anhydrous ammonia can be
used. The additional alkalinity should be mixed throughout the
lagoon contents to avoid localized pH variations that may inhibit
optimum biological reactions.
Temperature is one of the most important factors affecting
the performance of anaerobic lagoons. Because the lagoon is built
with the ground for insulation and is generally uncovered, tempera-
ture fluctuations can affect the biological system. The temperature
near the bottom of one 4-foot deep lagoon in Kansas has varied from
30°C in August to 5°C in February (44). As expected, anaerobic
lagoons function better in warmer climates and are less effective
in colder climates.
Gas production studies in an anaerobic lagoon treating
domestic wastes indicated that at liquid temperatures less than
13 to 14 C gas production was minimal (88). Maximum decomposition
and gas production took place at temperatures above 19 C. Insulation
-------
85
of the lagoon surface will minimize temperature changes during
the year. Styrofoam has been used for this purpose (89).
Anaerobic lagoons offer a possible approach for the treatment
of concentrated organic wastes. The lagoons provide excellent
settling capacity to intercept and separate heavy solids from
the liquid flow. The effluent liquid from the lagoon can be
quite potent. Table 27 summarizes the performance of a variety
of anaerobic lagoons. BOD reductions in the lagoons were respectable,
60 to 90%, however, such results were obtained at warm temperatures.
The effluent from lagoons handling animal manures contains
considerable organic material (Table 28). The effluent is high
in oxygen demanding material, solids, and nitrogen. Most of the
nitrogen in the animal wastes will be present in the effluent from
subsequent treatment units since conventional treatment units
remove only a small percentage of the entering nitrogen. The
quality of a receiving stream may be impaired if the effluent
from anaerobic lagoons is discharged without treatment, The
quality of the effluent is decreased during start up operations.
In practice, the quantity of liquid discharged from an anaerobic
lagoon treating animal wastes could be small, the volume depending
upon any runoff, the water used for cleaning of the facilities,
or animal drinking.
As noted above, the solids entering an anaerobic lagoon
vill decompose. The rate will depend upon such environmental
factors as the temperature of the lagoon, the degree of mixing
-------
86
TABLE 27
PERFORMANCE OF ANAEROBIC LAGOONS
Influent
Quality
(mg/1 BOD)
530
360
520
1100
15000
1380
Effluent
Quality
(mg/1 BOD)
160
85
100
160
1500
130
BOD
Reduction
Z
70
77
81
85
90
90
Reference
86
87
90
91
89
92
TABLE 28
EFFLUENT QUALITY OF ANAEROBIC LAGOONS
TREATING LIVESTOCK WASTE
85 255
6.5-7.5 6.5-7.5
4780 5900
Livestock Waste Swine Poultry Beef Beef
Loading Rate
(Ib. VS/day/1000 ftJ) 0.36-3.9 4-11
pH 6.7-8.0 6.8-7.9
Total Solids (mg/1)
Volatile Solids
(mg/1) 850-2330 - 2870 3710
Volatile Acids
(mg/1)
Alkalinity (mg/1)
BOD5 (mg/1)
COD (mg/1)
Total Nitrogen
(mg/1) - 113-290 360 500
72-528
1120-2220
-
940-3850
-
-
320-1350
590-2550
120
2000
1340
4700
400
1400
1420
5500
Reference
31
30
61
61
-------
87
that takes place, and the pH and alkalinity in the lagoon. At
low temperatures, the quality of the settled solids will be quite
similar to those that entered the lagoon. Little decomposition
will take place.
The amount of decomposition depends upon the biodegradability
of the entering solids. It has been shown that a 50 to 60% reduc-
tion of volatile solids in raw domestic sludge can be expected.
Studies with beef cattle manures have demonstrated a volatile
solids reduction of between 40 and 55% under equilibrium conditions.
Thus in an anaerobic lagoon treating similar wastes, at least 50%
of the entering wastes will accumulate in the period between lagoon
cleanings.
Consideration must be given to the disposal of the accumulated
solids. Table 29 illustrates the characteristics of these solids
as determined in laboratory studies investigating treatment of cattle
wastes. Land disposal of these solids could be an acceptable method
of ultimate disposal.
A design loading rate for a specific anaerobic lagoon will be
determined by the rate of residual solids build-up and by the
frequency of lagoon cleaning. The accumulation of material in the
lagoon is closely associated with the time between lagoon cleanings.
Where cleaned twice a year, a volume of 3.5 cubic feet per bird has
been suggested for chicken operations (94). An anaerobic lagoon
handling chicken manure contained 11.7% dry matter after 16 months
use (95). The chickens were on slat floors above the lagoon.
-------
88
TABLE 29
CHARACTERISTICS OF BOTTOM SOLIDS*
ANAEROBIC LAGOON UNITS (93)
Loading rate
(TS/cu ft/day) 0.1 0.1 0.3 0.4
Detention time (days) 10 20 10 10
(Theoretical)
BOD5/TS 0.16 0.13 0.14 0.14
BOD5/VS 0.20 0.16 0.18 0.18
COD/TS 1.1 1.1 0.85 0.96
COD/VS 1.4 1.4 1.1 1.3
pH 6.9 7.0
Volatile acids (mg/1) 700 800
Alkalinity (mg/1) 2340 2710
Total Kjeldahl 1720 1920 2000 2440
Nitrogen (mg/1)
The gaseous by-products of anaerobic digestion were not detrimental
to the chickens.
Anaerobic lagoons or ponds have been created by accident and
by design, the latter generally being more successful. Niles (38)
described two anaerobic ponds treating chicken wastes successfully
and noted that objectionable odors were not prevalent and that
active digestion occurred in the ponds.
There is a tendency to house animals on slatted floors above
both anaerobic and aerobic lagoons. Several problems have been
noted when anaerobic lagoons have been installed under poultry
-------
89
houses (97): (1) damage to the eyes of the birds, (2) off-flavor
eggs, (3) production of drone flies and maggots, and (4) odors
that perturb those on and adjacent to the property.
The use of anaerobic units for manure-holding prior to land
disposal appears to have some favor with farmers and dairymen
(56,98). Active digestion may or may not take place in these
units. When the contents are agitated prior to pumping, odors
do occur. The units are cleaned whenever the operators can get
onto the fields.
Anaerobic-Aerobic Systems
While anaerobic systems can be effective in treating animal
wastes, the effluent from such systems requires further treatment.
Combination anaerobic-aerobic systems may produce an effluent
which meets desired water quality standards. An anaerobic unit
can serve to equalize any periodic slug loads from confinement
feeding operations and can provide for partial degradation,
solubilization, and gasification of organic matter. The aerobic
unit can provide aerobic stabilization of the soluble and re-
maining particulate matter in the anaerobic unit effluent.
Additional units to provide for removal of the biological
solids in the effluent from the aerobic unit, for further
organic removal, and for removal of nutrients may be necessary
in certain cases.
Although used for domestic and industrial wastes, only
recently have combination anaerobic-aerobic treatment systems
-------
90
been utilized for treatment of animal waste, Morris (19) reviewed
the economics of treating wastes from confined livestock areas
and concluded that only in exceptional cases will farm income be
adequate for such treatment in traditional sewage treatment plant
processes. He suggested combination systems for treating animal
wastes when they cannot be distributed upon the land.
Systems combining an anaerobic lagoon, or anaerobic solids
holding tank, and an aerobic unit have been investigated for
treating wastes from animal confinement units (7,44,56,99). The
aerobic unit can be a traditional oxidation pond or an aerated
unit depending upon the land available, The above reports
indicate that a combination system can provide a high quality
effluent when the parameter of efficiency is percent removal.
The effluent will contain oxygen demanding material, and
inorganic nutrients and is not of the same quality as that
produced from municipal wastewater treatment plants.
Land Disposal
The land has been the ultimate disposal point for the solid
wastes of agricultural operations. Agricultural wastes, especially
animal wastes, maintain and improve the soil because of the plant
nutrients and organic substances they contain. Manure is one of
the logical ways to build and maintain fertile soils. Significant
amounts of basic plant nutrients are provided and the organic
matter in livestock manure improves soil tilth, increases water
holding capacity, lessens wind and water erosion, improves aeration
-------
91
of the soil, and has a beneficial effect on soil microorganisms.
The nutrient content of animal wastes is summarized in Tables
8-11 and 13-15.
Hart (100) suggested thin spreading as a method of applying
fluidized manure to land. Thicknesses of 1/25 to 1/5 inch,
depending upon the season, were suggested to avoid fly breeding
and to accelerate the drying. Cumulative layering of thin
layers of manure is possible, reducing the land area needed.
Hart indicated that less than 200 square feet per cow and 1
square foot per chicken would be sufficient for drying operations
in areas where open air drying is feasible.
To avoid pollution caused by runoff, the wastes should be
incorporated with the soil soon after spreading. Subsoil
injection as a method of manure disposal (101) has shown definite
promise. Two inches of poultry manure were deposited in the
bottom of a furrow and covered immediately. The rate of disposal
was estimated as about 200 tons per acre. For over three years,
the wastes from 1000 chickens has been plowed into one-half
acre of land with no odor offensive to neighbors (122). The
maximum land application that can be handled in this manner
will depend upon the type of soil, possible build-up of toxic
materials in the soil, and potential ground water pollution.
Land application primarily has been used to recover the
nutrient content of the wastes and to increase crop production.
Land application for the purpose of disposal only has not been
-------
92
practiced to any large extent. Confinement feeding of animals has
altered the feasibility of land disposal of such wastes. Large
quantities of waste are defecated in concentrated areas and must be
transported to the disposal site. It is virtually impossible to
apply the waste to cropland during the growing season. The farmer
usually can buy and apply chemical fertilizers more inexpensively
than he can utilize free animal manure.
For the above reasons, liquid holding units and liquid disposal
of the wastes on the land have promise as a method of efficiently
handling animal wastes. With such holding units, the liquid can
be applied to cropland while the land is fallow and when it is
convenient for the farmer. Liquid manure disposal systems are
being accepted by certain operators (22,23,56,102). Holding
tanks with two months or more capacity have been suggested for
freedom from continuous spreading (102).
Utilization of animal manures as a fertilizer or soil
conditioner is no longer as economical as it has been. In 1957
the commercial fertilizer equivalent of one ton of manure could
be purchased for about $2.50 (103). The expense of applying a
commercial fertilizer is less than that of applying manure. On
soils of good tilth, the returns from an equivalent amount of
fertilizer usually will be greater than from manure.
On many farms, the value of the nutrients contained in manure
does not offset the investment and labor required to give the manure
the special handling necessary. Eby (104) noted that in 1966, the
-------
93
value of manure averaged about $4 per ton while the cost in time,
labor, and equipment needed to move the manure from point of
origin to point of use could run as high as $6 to $8 per ton.
He suggested that land disposal represents a "least expensive
method of disposal."
Riley (105) indicated that in England the value of 1000 gallons
of poultry manure was about 1 pound per week per 1000 birds and that
it cost 5 pounds per 1000 gallons to move the manure and dispose
of it on the land. The philosophy of this article, that one
might as well utilize the nutrient value of the manure since it
must be moved anyhow, is typical of the thinking of many farmers.
Where wastes are liquid, land disposal by spraying (106)
has been suggested. Application rates from 1/3 to 1 inch per
acre have been feasible depending upon soil type. Problems
inherent in spraying include the land area required, equipment,
and odor production during and after spraying. The long term
effect caused by spray irrigation or land disposal of material
containing small amounts of toxic metals such as are in animal
wastes from animal feeding has not been evaluated (107). Cumu-
lative damage to arable and horticulture land is a possibility.
Incineration and Drying
Anaerobic and aerobic treatment can reduce the pollutional
characteristics of waste solutions but reduce very little the
total waste volume to be handled. Land disposal of wastes can
involve significant logistic problems as well as subsequent
-------
94
pollution of ground and surface vaters. Incineration and drying
have been suggested to reduce the total volume of the wastes and
to minimize water pollution problems.
Investigative work on animal wastes has been limited to poultry
manure. Ludington (108) found the heat of combustion of poultry
manure to be 5400 to 5800 B.T.U. per pound of dry matter. The
cost of fuel needed when the manure contained 807, moisture was
triple that needed when the manure contained 70% moisture. The
ash would require further handling. The ash in poultry manure
will run between 20-25% of the initial dry matter. Air pollution
is an inherent liability of the process calling for adequate control
and abatement.
There are indications that manure with a moisture content
higher than 30% cannot be fed directly into the combustion
chamber of an incinerator. Pre-drying, possibly using waste
heat from the incinerator, would be necessary. The need for
pre-drying is less acute for animal manures that are not diluted
such as those from cattle feedlots and certain hog operations.
Dry waste collection systems are necessary if incineration is to
be used.
Ludington (108) estimated that dehydration would not be
economical unless the product can be sold for at least $30 per
ton since, depending upon the moisture content, the cost of
dehydrating poultry manure is of that magnitude. The marketing
potential of dehydrated manure is unknown. It should be noted
-------
95
that composting, which produces a similar product, has not been
economically successful in this country due to a lack of a ready
marke t.
Niles (38) utilized a commercial manure drier to handle the
wastes and dead birds from a chicken operation of about 200,000
laying hens. The dried manure was bagged to be sold as a soil
conditioner. He felt that drying was the best approach since
aerobic treatment, centrifugation, sedimentation, and hydroponic
agriculture were shown to be uneconomical for this operation.
Miscellaneous Processes
In addition to those noted above, various other processes
have been used to handle and/or treat the waste from confinement
animal operations. Because of technical or economic difficulties,
these processes have not found wide application.
Wiley (109) reviewed the operation of three composting plants
treating animal manure. The plant operations included windrow
composting of a combined manure from 5500 steers plus the wastes
from a meat packing operation, rotary drum composting of the manure
from an operation handling a million chickens followed by windrow
composting for completion, and rotary drum composting of the waste
from one million layers. The detention time of the latter
operation was six days, All plants worked well and produced
suitable compost.
Livshutz (110) also used composting for poultry wastes.
He suggested covering windrows with plastic, forced aeration,
-------
96
and recirculation of the air for efficient and economical utili-
zation of the oxygen. An optimum moisture content of 40 to 60%
was recommended.
Howes (116) investigated on-site composting of poultry manure,
i.e., within the poultry house. The poultry litter was inoculated
with selected microorganisms to aerobically decompose the resulting
manure. He reported that the process was relatively inexpensive,
provided an odorless and fly-free environment, and kept dust to
a minimum.
A suitable market must be available before composting can be
attractive as a method of waste treatment and disposal. While
composting may be feasible for isolated animal production units,
it is doubtful that it is suitable for the volume of animal
wastes generated throughout the country. Without a market,
virtually all of the original dry matter remains for further
disposal.
Cassell and Anthonisen (18) evaluated vacuum filtration
as a method of reducing the volume of poultry manure. Ferric
chloride, ferric chloride and lime, and nonionic and cationic
polyelectrolytes were ineffective. Anionic polyelectrolytes
effectively dewatered chicken manure. The specific resistance
was reduced by as much as a factor of 15 and filter cakes as
high as 25% total solids were produced. Polyelectrolyte dosages
of 1.9 to 3.67o of the initial total solids content were required,
A ton of manure containing 1070 solids would require a maximum
-------
97
of 7.2 pounds of polyelectrolyte. No data were presented on the
quality of the filtrate or on possibilities of its disposal or
treatment.
Dewatering of farm slurries from dairy cattle housing using
drying beds has been explored (43). Measurements of specific
resistance to filtration showed that these slurries would drain
more slowly than most sewage sludges. Only a small amount of
water was removed by drainage. Evaporation of that remaining
would take an excessive length of time. The initial rate of
drainage was markedly increased by conditioning with aluminum
chlorohydrate. The filtrate, however, contained nearly 2?0
suspended solids.
Lime and chlorine have been used to suppress odors in
hog wastes and to provide some degree of treatment (111).
The wastes were collected from beneath self-cleaning slotted
floors where anaerobic conditions had created objectionable
gases and odors. Lime treatment reduced the BOD of the
effluent by about 50%, possibly by precipitation of organic
matter. About 0^15 pound of lime per 100-pound hog per day
was required to maintain the pH at 10,0, Over a six-months
period this amounted to $0,62 per hog. The chlorine demand
of the wastes was about 0.1 pound active chlorine per 100-pound
hog per day or about $6^40 per hog for a six-months period.
About half this concentration would suppress odors.
-------
98
Irgens and Day (40) noted that chlorination of diluted swine
waste eliminated some of the odor and improved flocculation and
dewatering. The COD of chlorinated and filtered waste was reduced
about 72%.
Treated effluent that will satisfy BOD and solids requirements
will still contain excessive bacterial concentrations. Chlorination
may be necessary prior to discharge to receiving waters. Gates (76)
investigated lagoons for use at duck farms and noted that the
chlorine needed to reduce the coliform density in the effluents
to 2300 per 100 ml or less ranged from0.85 to 4.6 pounds per
1000 ducks per day. Subsequent studies indicated that 24 pounds
of chlorine per 1000 ducks per day was needed to reduce the
coliform count to less than 100 per 100 ml in a 30 minute contact
period or about 1.32 cents per duck over a seven week growing
period (116). The economics of chlorination became more favorable,
0.3 to 0.4 cent per duck over the growing period, when biological
treatment of the duck wastes was satisfactory.
Dilute wastes, such as waste waters from farms, are amenable
to conventional treatment processes. Quiescent settlement of
cow and dairy shed washings for one hour reduced the BOD and
suspended solids content by 11 and 55% respectively (112).
Cattleshed washings can be partially purified with chemical
coagulants but such treatment increases the ultimate volume of
the solids. Painter (71) reported that the addition of 500 mg/1
-------
99
aluminum sulfate followed by sedimentation for one hour reduced
the BOD and suspended solid content of cattleshed washings by
30 and 76%, respectively.
Trickling filters have been successful in certain cases.
Painter (71) indicated that when coagulated cattleshed wastes
were applied to laboratory filters, effluents contained 20 mg/1
BOD. Dilution and recirculation of filter effluent were necessary
for successful treatment without coagulation. The influent BOD
was about 570 mg/1. Field trickling filter experiments at lower
temperatures, variable application rates, and lesser initial
dilution were less successful. In these cases the effluent BOD,
after settling, ranged from 40 to 140 mg/1.
Wheatland and Borne (113) used trickling filters to treat
settled farm wastewaters in a field installation. Loading rates
2
ranged from 0.08 to 0.14 lb. BOD/yd /day, and the filter influent
contained from 680 to 1390 mg/1 BOD5 and 100 to 224 mg/1 suspended
solids. The settled filter effluent contained from 12 to 50 mg/1
BODr, 8 to 155 mg/1 suspended solids, and usuallywas well nitrified.
Ponding was infrequent.
Bridgham and Clayton (115) treated dairy manure with trickling
filters preceded by sedimentation tanks. Loadings ranged from 6 to
22 pounds of BOD per 1000 ft3 of filter volume. Effluent BOD concen-
trations ranged from 80 to 750 mg/1 and varied with temperature and
loading. Scum and sludge were not removed from sedimentation unit
which became overloaded and released solids to the trickling filter.
-------
100
The waste entering the sedimentation unit was 2 pounds of manure
mixed with one gallon of tap water and added daily to the sedi=
mentation unit. This concentration purportedly simulated the
concentration of flushings from many dairy operations.
Animal wastes contain considerable energy and nutritive
value. The gross energy value of chicken feces ranged from
3.22 to 4.48 calories per gram of dry matter and the nitrogen
content from 0.03 to 0,07 gram of nitrogen per gram of dry
matter depending upon the feed ration (117), The utilization
of dried chicken manure as part of the feed for chickens and
ruminants has been suggested (117-121). Bull and Reid (117)
concluded that chicken manure could be fed to dairy cattle if
dried to 80% dry matter or more. The milk produced from
cattle on such feed was normal.
Beef animals and sheep can utilize broiler litter as part
of their feed (119). The race of gain and carcass grade were
not significantly different for beef steers fed 25% broiler
litter. The taste of the meat was unaffected. In another
study, sheep and steers readily consumed a combination of
cattle feedlot manure and hay (120), It was concluded that
combining such material offers the cattle feeder a challenging
opportunity to improve feed efficiency and at the same time
reduce the cost of removing manure from feeding pens. A
third study (121) found that concentrated cattle manure could
be successfully fed to pullets and laying hens. Egg production was
-------
101
affected only slightly. Catfish were also found to make rapid
gains on feedlot manure if care was taken to prevent oxygen depletion.
European Practice
Allred (122) recently visited Northern Europe and reported on
current animal waste disposal practices there. The following
statements are taken from the report of his visit, Problems in
Europe have become acute due to public awareness of the effects
of water pollution and the necessity for farmers to reduce labor
costs through mechanization. Legislation in every country pro-
hibits the dumping of any waste materials within a watershed where
they will contribute to the pollution of surface or ground water
supplies.
Several approaches to the handling and disposal of livestock
manure were in use. The most common was the distribution and use
of manure on farm land as an aid to soil fertility, tilth, and
structure. Partial reduction by anaerobic digestion, with
residues applied to the soil, has been attempted on a limited
scale with divergent degrees of success. Attempts are made to
aerobically oxidize and stabilize animal wastes, primarily in
oxidation ditches, to a degree that the sludge residue can be
disposed of on the soil and the liquid effluent to receiving
streams. Methods employing drying, bagging, and marketing of
the dried material as a fertilizer are being attempted. No plants
attempting complete incineration of farm manure were observed.
-------
102
The farmer and research worker in northern Europe place
greater importance on the use of manure for soil building purposes
than do their counterparts in the United States. In Europe,
greater research effort is being directed toward methods of
handling and hauling manure to the field rather than the design
and construction of major treatment facilities at each farm.
The manure cellar system, commonly found in Norway, was
perhaps the least costly and most simple system of manure handling
noted. Animals are housed on the first floor level of a barn and
manure wastes are dropped through slatted floors or open manholes
into the basement manure cellar. The cellars are made sufficiently
large to accommodate several weeks storage. At intervals depending
on weather and field soil conditions, the manure is removed from
the cellars and distributed on the fields. The cellar system
has advantages for hilly terrain but was less prevalent in areas
of flatter terrain. Ventilation of the animal area was necessary
to avoid asphyxiation of the animals by gas generated during the
manure storage.
Underground manure holding tanks, located outside of, but
adjacent to, the animals, also were common. Adequate storage
capacity was essential.
Allred (122) noted that most farmers expressed the desire
for larger holding tanks than they presently had. Because of
increased mechanization usually associated with the installation
of slurry or liquid manure type facilities, farmers often increased
-------
103
their herd size after the system was placed in operation with a
concurrent increase in the frequency of emptying the holding tanks.
The holding tank was the most costly part of most manure
disposal systems. The increased initial cost of a larger tank
was often justified by a saving in labor and the ability to permit
the farmer to empty the tank less frequently and at more opportune
times.
Both sprinkler irrigation systems and tank wagons were used
to transport the manure slurry to and distribute it on the fields.
Nozzles that permitted large solids to pass were advantageous.
Chicken and cow manures were dehydrated and marketed as
fertilizers in the Netherlands, Sweden, and Germany. Only fresh
manure and manure relatively free from sand and other inorganic
materials were used. The packaged product had a moisture content
of less than 10% and sold for about $50 per ton. Allred noted
that manure dehydration companies appeared to be facing difficult
price competition because of the availability of relatively inexpen-
sive commercial fertilizers.
Apparently, anaerobic digestion of animal wastes was utilized
as a source of methane gas during and following World War II. This
practice became uneconomical when fossil fuels again became available.
Controlled anaerobic digestion of animal wastes was not practiced
at the time of Allred's visit.
The traditional oxidation pond or aerobic lagoon had not met
with success in Northern Europe due to the limited land area available
-------
104
and the relatively cool temperatures. Considerable interest has
been generated in the oxidation ditch for treatment of animal
wastes. The ditches occupy a smaller land area and employ mechan-
ical aeration for mixing and transfer of oxygen. Hog and dairy
wastes were stabilized in oxidation ditches. Individuals working
with the oxidation ditch as a method of treatment and reduction
of farm wastes were optimistic about its future possibilities.
Allred (122) presented no information on the number of
animals per farm or production unit, on loading conditions for
various treatment facilities, on surface and ground water pollution
that may have occurred, or on cost of treatment processes and
operations.
Morris (85) also has reported on European practices of animal
waste disposal. He noted the interest in controlled aerobic
methods of treating animal wastes especially in oxidation ditches.
Information describing European conditions in regard to animal
production and number of animals per confinement unit is scarce.
The available information suggests that animal concentrations in
the United States, i.e., on the order of 1000 or more beef cattle,
1000 or more hogs, and 10,000 or more chickens per confinement unit
are not matched in Europe. In fact Allred (122) noted that in some
European countries, the governments have established various types
of subsidy-incentive programs to encourage the retention of small
"family-size" farms. Disposal of farm manures is usually not as
-------
105
serious a problem in areas where livestock are widely dispersed
on many small farms.
European experience in the area of animal waste disposal can
serve as a guide for practice in the United States. However, the
availability of land, the trend toward large confinement units and
small numbers of production units, and even different temperature
and weather conditions in the areas of animal production in the
United States indicate that American animal waste disposal prac-
tices will be more diverse than European practices. Processes
that may be unsatisfactory in other parts of the world may be
suitable in the United States.
Summary
Considerable information is being accumulated by a number of
investigators on a variety of treatment processes applicable to
animal wastes. To date, each investigation has been done on a
relatively snail scale by one or two researchers working on a
particular project, Agricultural engineers of today do not have
a grasp of the fundamentals of waste treatment processes. They
frequently conduct research that has little chance of success and
use treatment processes under conditions that obviously lead to
disastrous results.
Sanitary engineers have little if any knowledge of animal
management practices, of the use of land as a disposal site for
wastes, of the economics of animal production, and of the impact
of waste treatment practices on the animal production industry.
-------
106
Coordinated, interdisciplinary activities involving sanitary
engineers, agricultural engineers, economists, agronomists, those
interested in animal husbandry, and others interested in the problem
are seriously needed. These activities should center around field
as well as laboratory research and demonstration projects. Funds
should be made available so that all data pertinent to a particular
project can be collected and evaluated. For example, a waste treat-
ment project should collect data not only on the usual parameters such
as BOD, solids, and bacteria but on conservative substances such as
nitrogen, phosphorus, chlorides, potentially toxic metals, antibiotics,
and so forth. Land disposal projects should collect data not only on
crop response but also on the effect of potential pollution caused
by rainfall and runoff, on travel of soluble components through
the ground, and on the maximum quantity of wastes that can be applied
to the land. The effect of various waste management practices should
also be evaluated within each project.
Training is seriously needed to bridge the gaps, and to merge
disciplines that must be involved in solutions to the problem.
However, training activities should not be the source of the major
research activity in this area.
Many treatment systems are in use. Few have been evaluated
closely to obtain pertinent loading, performance, and quality data.
Animal wastes are different in quality and quantity from domestic
. and other industrial wastes. Adoption of processes used for municipal
and industrial wastewater treatment are not likely to be successful
-------
107
with animal wastes unless process modifications are made for
differences in waste characteristics.
Because of the quality of animal wastes, anaerobic processes
will be a part of many feasible systems treating animal wastes.
Information is needed on the quality of effluent from these systems,
loading conditions, the effect that seasonal temperature variations
will have on performance and efficiency, and the need for and effect
of various mixing rates.
Anaerobic processes may be controlled and used as manure holding
facilities or controlled to accomplish optimum organic decomposition
as well. In either case, anaerobic processes by themselves will not
be sufficient. Subsequent treatment will be necessary. Aerobic
treatment processes can be used. Additional data are needed on
the quality of the effluent from the aerobic processes, the effect
of shock loading conditions occasioned by slug loading of preliminary
anaerobic units, the effect of temperature variations, and above all
the cost of operating and maintaining such systems.
The entire problem of the ultimate disposal of solids remains
untouched. Land application of waste liquids and solids has been
used for centuries but few data have been accumulated on the optimum
amounts of material that can be placed on the land, on proper manage-
ment techniques, on land disposal of wastes with different qualities,
on subsequent pollution that may occur, and on changes in soil
conditions that may result. Major emphasis to date has been on
crop response which, while valuable, provides little information
on disposal techniques.
-------
108
Land disposal is becoming less economical due to the large
quantity of wastes generated, the costs of transporting the wastes
to suitable disposal sites, and the availability of inexpensive
chemical fertilizers. Land disposal may continue to be a "least
expensive" way of ultimate solids disposal but alternative ultimate
disposal methods need to be evaluated. Incineration has been only
slightly investigated. Wet oxidation could be another possibility
in areas where concentrations of solids are large. Low temperature
wet oxidation can produce soluble organic components that may be
incorporated into animal feed. Sanitary land fill is another possi-
bility for dry and semisolid wastes. Biological reactions within
such a fill and possible ground water pollution need to be evaluated.
Feasible and economical water renovation processes need to be
evaluated not only to assure adequate water quality in receiving
streams but also to supply water for reuse on farms and in confine-
ment operations. Nutrients, chlorides, color, and trace metals
may prevent treated water from being reused for the above purposes.
The low volumes of water and the high concentrations of contaminents
that are in treated water will challenge those that attempt to obtain
suitable processes.
At present, there is no profitable method of livestock manure
utilization and it is unlikely that one will be developed. Animal
waste handling, treatment, and disposal will cost something. This
must be made clear to those that produce the animals and the public
-------
109
that consumes them. The cost of satisfactory waste treatment
will be related to the desires of the public to minimize
pollution from these sources, to the willingness of the
consumer to accept higher meat prices to pay for the treatment,
and to the ingenuity of those in all professional disciplines
in developing suitable treatment systems.
No one treatment process or treatment system will be the
solution for all animal production units. A variety of manage-
ment and treatment systems will have to be developed. Obviously
these systems must be consistent with American practice, needs,
and economies. Mass adoption of European practice will not be
adequate. Such practices, however, can be a guide for potentially
successful American systems.
-------
PART 7
COSTS
Introduction
The increase in confinement feeding of animals, noted in Part 3
of this report, has been spurred by a decreasing profit margin per
animal. The economics of pollution and nuisance control are an
important factor in the design and operation of confinement units
and may mean the difference between financial success and failure
for the owner. Stubblefield (123) described the difficulties
encountered in Arizona as the larger cities expanded and became
neighbors of or encompassed cattle feedlots. He noted that, while
feedlot relocation was a possibility, the feeders would lose over
50% of their capital investment if they did so.
Two general types of costs are pertinent to the solution of
the animal waste problem: (a) the cost of animal production and the
profit available for waste treatment and disposal facilities and
(b) the cost of constructing, operating, and maintaining adequate
treatment and disposal facilities.
Animal Production Costs and Profits
It has been reported (124) that the initial investments in
buildings and equipment for confinement units are in the range of
$3 to $6 per hen, $20 to $40 per hog, and $1,000 to $1,500 per
dairy cow. Within the cattle production industry, production has
been cyclic (Figures 4,5), but the long term production trend has
always been up. Experience has indicated that, approximately one
110
-------
Ill
year out of ten, cattle feeders do not obtain enough from the sale of
their cattle to pay for their feed. Recent information from the
Department of Agriculture noted that the average midwestern cattle
feeder fell 42 cents short of covering his production costs in
buying, feeding, and fattening a cow for the consumer slaughter
market during the first half of 1967 (139). Overhead costs, pasture
costs, and death losses were not included.
Feed can amount to 70% to 80% of the total cost of producing
slaughter cattle. Feed costs increase with the age and size of the
animal and the length of the feeding period. Table 30 illustrates
the financial return available to cattle feeders in recent years.
The data on the short-fed cattle are typical of what can be expected
of cattle feedlot operations. Although the short-fed cattle appear
to produce somewhat less profits such is not the case, because the
turnover of such cattle is rapid. At least two and frequently
three lots of short-fed cattle can be fed in the same feedlot per
year. Feeders in Arizona and California have had to develop more
efficient feeding methods because of high grain and roughage costs
to compete with feeders in the grain country.
The income to the producers from animal production since
1940 is illustrated in Figures 10 and 11. Although prices have
stabilized fairly well in the 1960's, the over-all trend has been
a decreasing unit income from chickens and hogs. With increasing
labor and equipment costs, constant and especially decreasing unit
costs mean that those in the animal production business are caught
in a cost squeeze. The result has been mechanization of the
-------
112
TABLE 30
CATTLE FEEDING SYSTEMS—1951-1963
Range
Returns Above Cost
System of Feed & Cattle
Long Fed*
Steer calves $85 to - $11
Heifer calves 79 to - 18
Yearling steers 81 to - 13
Short Fed**
Conmon-medium yearlings 80 to - 30
Choice yearling steers 62 to - 42
Heavy steers 66 to - 47
*Usually on farm more than 240 days.
**Usually on farm less than 240 days.
industry and increased confinement feeding of animals. The income
from milk production has been constant for many years, undoubtedly
due to price supports and governmental buying of milk. The cost
squeeze in the dairy business has resulted in a decrease in the
number of dairy farms and dairy cattle in the United States (See
Figure 2).
Studies on commercial cattle feedlot operations (126) indicated
that feedlots of 2,000 head or larger operating at or near capacity
may enjoy critically significant cost advantages over smaller volume
operations. Further studies (127) indicated that costs may be lowered
in cattle feedlot operations by increasing capacity to 5,000 head.
Additional economies in buying, transporting, and selling might be
gained in larger operations. Capital requirements for a 5,000
head operation would be relatively large, over $1 million for feed,
feeders, and feedlot services. Typical costs of cattle feeding
operations in several states are presented in Table 31. Small
-------
COMMERCIAL BROILERS
CENTS/POUND
10
CATTLE
DOLLARS/100 POUNDS
1940
1950
I960
1970
FIGURE 10
INCOME FROM BROILER AND CATTLE PRODUCTION
IN THE UNITED STATES ( 1 940-1965 )( 3 )
-------
HOGS-DOLLARS/HEAD
MILK-DOLLARS/100 POUNDS
1940
1950
I960
1970
FIGURE 11
INCOME FROM HOG AND DAIRY OPERATIONS
IN THE UNITED STATES (1940-1965) (3)
-------
115
TABLE 31
COST OF CATTLE FEEDING OPERATIONS
(CENTS/HEAD/DAY) (127)
Sjate Feedlot Capacity (number of head)
100 500 1000 2500 5000 7500 10,000
Illinois 13.4 -
California - - 14,2 11.2 9.2 9.3
Oklahoma - 14.5 12.1 11.5 10.6 10.4 10.2
feedlots have a relatively high unit cost. Prices for 180-day
feedlot service in Iowa and Nebraska were $25.76 per head in 1965
and $30.18 per head in 1966 (126). Between 15.3 and 16.8 cents
per head per day were sufficient to cover all costs on feedlot
operations»
Data on the difference between selling and purchase price
for various types of cattle are shown in Table 32. The invest-
ment and animal costs of feedlots of various sizes feeding short
fed yearling steers on pasture and drylot (Table 33) further
demonstrate the economics of confinement operations and of
mechanization. Investment and annual costs decrease as the
feedlot size increases and increase with increased mechanization.
Although the numbers will vary, similar comparisons exist for the
other types of cattle feeding systems noted in Table 32. Short
fed yearling and common steers are on feed approximately 180
days and are the type usually found in beef cattle confinement
feeding operations.
-------
116
TABLE 32
AVERAGE PRICE MARGIN
(DOLLARS) (128)
Cattle Feeding Systems
Long Fed Steer Calves
Long Fed Heifer Calves
Long Fed Yearling Calves
Short Fed Yearling Steers
Short Fed Common to Medium
Steers
Light Yearling Steers on Pasture
and Drylot
1952-1962
-0.49
1.
1.
2.
20
56
10
4.32
1.71
TABLE 33
INVESTMENT AND ANNUAL COST FOR SHORT
FED YEARLING STEERS* (128)
Feedlot
Capacity
(number
of head)
20
40
60
80
100
120
200
500
1000
Investment per Head
Limited High
Mechani- Mechani-
zation zation
249
199
170
162 229
155 203
151
166
147
124
Annual Cost per Head
(Dollars)
Limited
Mechani-
zation
27.60
21.70
18.40
17.50
16.75
16.20
High
Mechani-
zation
25.60
22.60
18.20
16.00
13.90
*Investment and annual cost in feed storage, buildings and
equipment, cattle fed hay, corn, and protein supplement.
-------
117
Stubblefield (123) reported that the profits from commercial
feeding of cattle can be respectable. He indicated that a net
profit of $5 per animal fed per lot turnover is possible. This is
the equivalent of $10 to $15 per head of lot capacity since two,
and sometimes three, lots of short-fed cattle can be fed in the
same feedlot per year.
Data on investment and annual costs for hog, chicken, and
broiler operations could not be located. Cost relationships in
these operations probably are similar in nature but not necessarily
in magnitude to those in the cattle industry.
Animal Waste Treatment Costs
A minimum of data is available to permit accurate estimates
of the cost of various treatment facilities for animal wastes.
Kesler (129) evaluated the cost of hauling and spreading, lagooning,
and combined lagooning, hauling, and spreading for various size
confinement hog operations. Costs of equipment, labor, construction,
and of fertilizer nutrients in the manure were included. His
results are presented in Table 34, Hauling and spreading was the
lowest net cost of disposing of hog manure when cropland was
available and the manure was used to replace commercial fertilizers.
The combination of lagooning, hauling, and spreading was the second
lowest net cost, Total lagooning was the highest net cost since no
nutrients were recovered and no credit applied„ This study assumes
that the farmer will pay close attention to the nutrient balance for
his crops and will not apply excess inorganic nutrients in addition
to those in the manure, The economics of scale on the waste dis-
posal techniques evaluated are apparent.
-------
TABLE 34
ECONOMIC EVALUATION OF LIQUID MANURE DISPOSAL
FROM CONFINED HOG OPERATIONS (129)
Number of Hogs pro-
duced annually
Annual Cost (dollars)
per hog
per 1000 gallons
Return above total
disposal costs*
(dollars)
Hauling and Spreading
500 1500 2500
0.69 0.37
3.82 2.05
-58 305
0.30
1.69
670
Lagooning
0.32
1.78
Hauling, Spreading
and Lagooning
500 1500 2500 500 1500 2500
0.28
1.56
0.28
1.54
0.79
4.37
-160 -421 -695 -107
0.43
2.39
213
0.36
2.02
521
*The value of the replacement costs of the salvaged manure is included as a credit to
the operator in all but the lagooning operation.
00
-------
119
Morris (19) reviewed the economics of liquid manure disposal
from confined livestock. He noted that the scale and efficiency
of the operation and prevention of dilution of the manure determine
if the manure can be spread on the fields at a cost equal to or less
than the value of nutrients used by the crop.
Liquid handling of manure followed by land disposal has been
accepted by confinement feeders because of the flexibility of the
method and because of the ability to recover nutrients in the
wastes. Costs of liquid holding and pumping systems have ranged
from $35 to $52 per head of dairy cattle at a variety of dairy
farms (102). Mixing of the contents of the holding tank was
done only during the pumping.
Sobel and Guest (26) reported costs of about $40 per head
of dairy cattle with adequate storage capacity and from $77 to
$133 per cow capacity for a commercial liquid system with waste
storage of one month,
Wolf (23) noted that sprinkler systems used for hog manure
disposal in England cost about SO.66 to sprinkle 1000 gallons of
liquid manure compared with $3.70 with a tank wagon spreader.
Labor, depreciation, and operating costs were included in these
values.
Power costs for oxidation ditches treating animal wastes
have been reported to be about 90 kw.-hr. per dairy cow and
72 kw,-hr. per pig (84), 36.5 kw.-hr. per pig (40), and 40 fcw.-hr.
per hog, and 328 kw.-hr. per dairy cow (83). These figures are
-------
120
per animal finished per year. The operating costs per year have
been estimated as 10% to 15% of the total cost of the ditch (39).
Morris (19) indicated that about 1095 kw.-hr. would be required
per dairy cow per year which would amount to about $1.50 per ton
of manure. He noted that the oxidation ditch did not seem to be a
lower cost method of manure disposal unless the cost of labor
associated with alternative methods was high, about $2 per hour.
Costs of dehydration of animal manure have been estimated
at $25 to $35 per ton of poultry manure (108). The costs depend
upon the moisture content, decreasing with decreasing moisture
content.
Livshutz (110) has indicated that the cost of composting
poultry manure using a plastic covering and forced aeration could
be between $25,000 and $50,000 for a farm handling 100,000 chickens.
Treatment Process Cost Comparison
More data are available on construction and operational cost
of facilities treating municipal wastes. Although these costs are
not directly applicable to animal wastes they can be used, together
with the above data, to provide gross estimates of the costs of
treating animal wastes by various processes. On the following
pages, estimates have been made of the land area, process size,
and, where available, costs of waste treatment processes for the
following confinement feeding operations: beef cattle—1,000 and
10,000 head, dairy cattle—100 head, hogs—1,000 head, chickens—
10,000 and 100,000 animals. Since waste production will vary with
the size of the animal, the following animal sizes have been assumed;
-------
121
dairy and beef cattle—1,000 pounds, hogs—100 pounds, chickens—
5 pounds. The assumed sizes of the confinement operations and of
the animals are typical in this country.
As observed from Part 4, data on characteristics of animal
wastes vary considerably due to a wide variety of factors. Table
35 summarizes the range of values reported in the literature and
the values that have been used for estimating treatment unit size
and costs in this part of the report. The values selected are
educated estimates of average values that appear to be realistic.
Liquid flow data for beef cattle feedlots are nonexistent.
Intermittent runoff would cause the only significant flow from
the feedlots in use at present (1967) .
The treatment processes selected for evaluation in this
comparison have been selected because of their applicability to
animal wastes. These processes are: oxidation ponds, aerated
units, anaerobic lagoons, anaerobic digestion, incineration,
composting, wet oxidation, and land disposal. A combined
anaerobic-aerobic system has also been included.
Oxidation ponds—Traditional oxidation ponds are designed
at between 20 and 40 Ib. BOD5/acre/day with a detention time of
30 to 90 days. The ponds are 4 to 5 feet deep for proper develop-
ment of photosynthetic action and wind mixing. Assuming a loading
rate of 30 Ib. BOD5/acre/day, the sizes of the ponds to treat the
wastes from the assumed animal feeding operations have been cal-
culated (Table 36). Because of the low liquid flows, the average
detention times are in the order of years. An additional source
-------
122
TABLE 35
SUMMARY OF ANIMAL WASTE
CHARACTERISTICS*
Dairy Beef
Cattle Cattle Hogs Chickens
Liquid flow from confinement operations (gallons/animal/day)
Range 5-30 - 1.6-6 0.05-.2
Value used in Part 7 10 - 5 .1
Manure Production (pounds/animal/day)
Wet Solids
Range 38-86 60-65 2.8-9.5 0.11-.39
Value used in Part 7 70 60 5 0.25
Dry Solids
Range 6.8-14 3.6-10 0.5-1.6 0.05-.10
Value used in Part 7 10 10 0.9 0.06
BODj (pounds/animal/day)
Range 0.94-1.53 1.02 0.20-.56 0.006-.032
Value used in Part 7 1.0 1.0 0.30 0.015
*Data from Part 4
-------
TABLE 36
SIZE OF POSSIBLE TREATMENT UNITS--
OXIDATION POND AND OXIDATION DITCH
Beef
Oxidation Pond
Surface area (acres)
Volume* (106 gallons)
Detention time (days)
Oxidation Ditch
Minimum Ditch
volume (f t^/animal)**
3
Ditch volume (ft )
Detention time (days)
Surface area (acres)
Oxygen Demand (Ib./day)
Horsepower Required
Dairy
Cattle
100 head
3.3
5.4
7100
50
5000
37
0.029
200
5
Cattle
1000 10,000
head head
33 330
54 540
-
50 50
50,000 500,000
-
0.29 2.9
2000 20,000
40 400
Hogs
1000
head
10
16
3200
7
7000
75
0.04
600
12
Chickens
104 105
birds birds
5
8.2
8200
1
10,000
375
0.057
300
6
50
82
8200
1
100,000
375
0.57
3000
60
Length of Rotor
required (ft)
NJ
U)
2.8
28
280
8.5
4.2
42
*Pond 5 feet deep
**Data from Part 6
-------
124
of water would be needed to fill the ponds due to the low influent
waste flows. The small inflow could cause difficulties in maintain-
ing a proper water depth and balance. This problem would arise
whenever the net outflow, including seepage and evaporation, was
larger than the net input of rainfall over the pond surface by
more than the waste inflow. This critical difference would be
about 3.1 in./yr, 6.7 in./yr and 2.7 in./yr for oxidation ponds
treating the waste from dairy, hog, and chicken operations
respectively. These numbers are equivalent to the waste inflows
to the ponds. The bottoms of oxidation ponds are sealed to
prevent ground water pollution and to maintain proper water levels.
Some seepage does occur. The amount permitted by various Departments
of Health range from 0.1 to 0.25 in./day (36 to 90 in./yr). The
waste inflow from the assumed confinement operations would not be
adequate to overcome permitted seepage losses. An additional
source of water would be needed to maintain proper water depth.
The ponds would be nonoverflowing. This has distinct
advantages for pollution control. The large land area needed
and the need for make-up water can be disadvantages.
The design of oxidation ponds for treatment of animal wastes
is controlled by the BOD loading and not the hydraulic loading,
assuming adequate water depth is maintained. Many oxidation ponds
have been successful at BOD loading rates considerably in excess
of 30 Ib./acre/day (130,131) especially where temperatures are
warm and considerable sunlight and wind prevail. In areas where
-------
125
loadings higher than those assumed in this report can be maintained,
the size and cost of the oxidation ponds, and the quantity of needed
makeup water would be decreased.
It is difficult to utilize the costs of oxidation ponds treating
municipal waste to estimate the cost of ponds treating animal wastes.
Hydraulic and BOD loading conditions control the design of ponds
treating municipal wastes while only BOD loading controls ponds
treating animal wastes. Land costs vary throughout the country but
are likely to be low in areas where the confined animal feeding
operations are located.
Aerated Unit--In an aerated unit oxygenation is accomplished
by mechanical or diffused aeration and by induced surface aeration.
The turbulence level maintained in the unit insures adequate distri-
bution of oxygen but is usually inadequate to maintain solids in
suspension throughout the unit. Because sunlight is unimportant,
aerated units can be deeper than oxidation ponds. The mechanical
or diffused aeration permits units that are considerably smaller
than equivalent oxidation ponds. Land costs decrease but operational
costs are greater due to the need for power to supply the necessary
oxygen.
The oxidation ditch is the most common type of aerated unit
used for the treatment of animal wastes. Minimum ditch volumes,
surface areas, oxygen demand, and other factors relating to oxidation
ditches treating the wastes from the assumed animal production units
are tabulated in Table 36. The following assumptions were made:
-------
126
depth, 4 feet; two pounds of oxygen needed per pound of BOD applied;
50 pounds of oxygen per horsepower per day; and three pounds of
oxygen per hour per foot of rotor. The actual horsepower, oxygen
transfer, and length of rotor requirements are related to the depth
of submersion and rotor speed.
Anaerobic Lagoons—Anaerobic lagoons are a possible method
of handling and treating concentrated animal wastes with their
high solid and low water content. Attention must be given to the
environmental conditions affecting the biological reactions in
the lagoon if it is to be operated as a controlled biological
process.
As noted in Part 4, anaerobic lagoons can be loaded at high
rates. Loadings from 0.4 to 320 Ib. VS/day/1000 ft3 have been
successful with animal wastes. A design loading rate for a specific
anaerobic lagoon will be determined by the rate of solids build-up
in the lagoon and the desired frequency of lagoon cleaning. A
trade-off between size and cleaning will exist. A larger lagoon
will require more land area but less cleaning, and a smaller lagoon
just the opposite. Two loading rates, 50 and 200 Ib. VS/day/1000
3
ft , have been used to estimate relative sizes of anaerobic lagoons
for the confinement animal feeding operations previously assumed
(Table 37). The depth of all lagoons has been assumed at 10 feet.
The animal wastes have been assumed to contain 8070 volatile material.
Seepage and evaporation could be less than the waste inflow,
under the assumed conditions, and the anaerobic lagoons would have
-------
TABLE 37
SIZE OF POSSIBLE TREATMENT UNITS--ANAEROBIC LAGOON AND
COMBINED ANAEROBIC-AEROBIC SYSTEM
Anaerobic Lagoon
Loading - 200 Ib. VS/1000 ft3/day
Volume (ft3)
Surface area (acres)
Detention time (days)
Loading - 50 Ib. VS/1000 ft3/day
Volume (ft3)
Surface Area (acres)
Detention time (days)
Combined Anaerobic-Aerobic System
Anaerobic Unit - 50 Ib. VS/1000 ft3/day
Dairy
Cattle
100
head
4,000
0.009
30
6,000
0.037
120
Beef
1000
head
40,000
0.09
—
160,000 1
0.37
-
Cattle
10,000
head
400,000
0.9
—
,600,000
0.37
-
Hogs
1000
head
3,600
0.008
5
14,400
0.033
22
Chickens
1
-------
128
an overflow. As noted earlier, such overflow will have a high
oxygen demand, and contain organic material, aquatic nutrients,
and esthetically undesirable items such as color and chlorides,
Anaerobic lagoons are likely to be used as part of a treatment
system rather than the sole treatment unit.
Combined Anaerobic-Aerobic System—Since the effluent from
an anaerobic unit can be potent, a combined anaerobic-aerobic
system will be necessary if the liquid effluent is discharged
to a receiving stream. A conservative estimate of the performance
of an anaerobic lagoon would be that, under the worst of conditions,
i.e., cold temperatures, little microbial activity, it will act
as a sedimentation unit. Under more favorable conditions, i.e.,
controlled environmental conditions, both sedimentation and
biological degradation will take place.
It was assumed that approximately 50% BOD reduction would
take place in the anaerobic lagoon preceding the aerobic unit,
The size of the resulting aerobic unit, an oxidation pond or
oxidation ditch, and the size of the over-all system are shown
in Table 37.
Anaerobic Digestion--Controlled anaerobic systems are another
possibility because of the characteristics of animal wastes. Data
on mixed and heated anaerobic digestion systems treating solids from
municipal and industrial solids indicate that loadings of 0.2 Ib. VS/
ft /day and above are quite feasible.
While high-rate anaerobic digestion has the advantages of
comparatively small volumes and a usable end product, methane,
-------
129
certain costs are involved. These include those of mixing and
heating as well as the cost of the physical plant and the cost
of digested sludge disposal facilities. Data at the Chicago
municipal treatment plants (132) indicated that annual costs of
digesting municipal sludge varied from $32 to $14 per ton of
sludge fed to the digesters as the feed solids varied from 2 to
8%. Animal waste can be fed to high rate digesters at 1070 or
more solids. It is not unreasonable to estimate the costs of
high-rate digestion for animal wastes at about $10 per ton of
dry solids. The size and cost of units for the solids produced
in the assumed animal confinement operations are shown in Table
38. The above costs represent the annual cost, that is, the
capital recovery, maintenance and operational costs, of sludge
solids digestion facilities. The initial cost of constructing
the digestion facilities has not been determined.
Incineration--Biological treatment can reduce the pollutional
characteristics of animal wastes but does little to reduce the
volume to be handled. Incineration can reduce the volume. The
residual volume, the ash, may be 20 to 257. of the original total
solids and perhaps 3 to 47» of the wet animal waste.
Animal wastes can be collected in a relatively dry state,
80 to 8570 moisture. There is a certain logic to handling these
wastes as a solid rather than diluting them with water and handling
them as a liquid slurry. When water is added for dilution, both
the water and original solids must receive treatment.
-------
TABLE 38
SIZE OF POSSIBLE TREATMENT UNITS--HIGH RATE
ANAEROBIC DIGESTION AND WET OXIDATION
High Rate Anaerobic Digestio
Volume (ft3)
Annual cost
per year per animal
capacity per year
Wet Oxidation
Dairy
Cattle Beef Cattle Hogs Chickens
100 1000 10,000 1000 10* 105
head head head head birds birds
n (.20 Ib. VS/ft3/day)
4,000 40,000 400,000 3,600 2,400 2,400
$1,820 $18,200 $182,000 $1,650 $1,100 $11,000
$18.2 $18.2 $18.2 $1.65 $0.11 $0.11
High Pressure
Construction cost
per unit
Annual cost
per day
LOw Pressure
Annual cost
per day
$25,000
$5
$250,000 $1,500,000
$50 $500
$22,500 $15,000
$4,5 $3
$150,000
$30
$1.50
$15
$150
$1.35
$0.90
$9
u>
o
-------
131
While few data are available on the cost of incinerating
animal wastes, cost data are available for the incineration of
municipal solid wastes (133). Most incinerators for municipal
solid wastes cost from $3,000 to $4,000 per ton of rated 24 hour
capacity to build and equip.
Operating costs have ranged from $2 to $6 per ton of refuse
processed. The cost of incineration of sewage solids has been
given as $30 per ton of dry solids (134). The large quantity
of wastes generated from large animal confinement operations
suggests that incineration might be feasible. The construction
and operating costs for an incinerator to handle the solids from
the assumed animal confinement operations are listed in Table 39.
The costs that were assumed were: construction, $3,000 per ton
of 24 hour capacity; operating costs, $5 per ton of waste processed.
Adequate air pollution control and abatement equipment will
be needed. The cost of such equipment will be in addition to the
costs estimated in Table 39.
Compos ting—Compos ting offers the possibility of retaining the
nutrients contained in the animal wastes for subsequent use on the
soil. Previous enthusiasm for composting in the United States has
been due largely to the possibility of producing a saleable and
possibly profitable product. Evidence and experience in this
country indicate that, except in special cases, composting should
be thought of as a treatment process and not as a profit making
operation.
-------
TABLE 39
Incineration
Construction cost
Annual Costs
per day
per animal capacity
per year
Composting
Land Disposal
Thin spreading
Area (acres)
Sub-soil Injection
100 tons wet solids/acre
Area (acres)
10 tons wet solids/acre
Area (acres)
Spraying (.05"/acre)
Area (acres)
SIZE OF POSSIBLE TREATMENT UNITS--
INCINERATION, COMPOSTING, AND
LAND DISPOSAL
Dairy
Cattle
100
head
Beef
1000
head
Cattle
10,000
head
Hogs
1000
head
Chickens
105
birds
KP
birds
$1,500 $15,000 $150,000
$1,350 $900
$2.50 $25 $250 $2.25 $1.50
$9.20 $9.20 $9.20 $0.83 $0.55
Estimates are the same as for incineration
0.46
0.035
0.35
7.3
4.6
0.3
46 0.46 0.23
0.02 0.013
30 0.2 0.13
$9,000
$15
$0.55
3.7
7.3
2.3
0.13
1.3
73
u>
ts>
-------
133
Capital costs are relatively high. Costs will approximate
those of an incineration plant for a comparable amount of refuse
disposed. Capital costs may range from $1,000 to $6,000 per ton
of capacity with plant operating costs varying from $2 to $5 per
ton of solids received at the plant (133). When nonsaleable, the
compost will require further disposal. The costs of incineration
operations have been used to estimate those of composting (Table
39).
Wet Oxidation--Wet air oxidation is a process in which the
organic matter is heated with air to an initiating reaction
temperature, usually between 300° and 400° F. The mixture then
enters a reactor where the desired oxidation takes place. The
degree of oxidation depends on the temperature, pressure, holding
time, and concentration of the sludge entering the process. Oper-
ating pressures may be from 100 to over 3,000 psi depending upon
the degree of oxidation desired. When the solids content of the
entering organic matter is over 4 to 6%, the process taay be
thermally self-sufficient. The process has been used for the
treatment of municipal and industrial waste solids.
High pressure wet oxidation can be rather complete, providing
up to 90% COD reduction. The remaining liquid, containing perhaps
6,500 rag/1 soluble BOD and ^000 mg/1 total nitrogen requires further
disposal. Construction costs have been estimated at about $50,000
per ton of dry solids per day for small plants having a capacity of
about 5 tons per day and $25,000 per ton for plants with capacities
of 100 tons per day. Operating costs ranged from $6 to $15 per ton
-------
134
of dry sludge solids processed (135). An average cost of $10 per
ton was used to estimate the animal costs for high pressure wet
oxidation noted in Table 36.
Low pressure batch type plants might be better suited for
use with wastes from animal confinement operations. The effluent
from a low pressure plant would contain soluble organic compounds
and partially oxidized sludge that might be reused in the feed
ration of the animals in confinement, the nonbiodegradable
compounds such as lignin, being oxidized to a more biodegradable
form. Construction costs would be somewhat less than those of
the high pressure system. Operating costs for low pressure
sludge oxidation systems have ranged from $2 to $4 per ton of
dry solids processed (136). A cost of $3/ton was used in the
estimates noted in Table 38. Advantages accruing from the low
pressure system would be due to simpler operation, less operating
personnel needed, and possible reuse of the system effluent as a
portion of the animal feed.
Estimated costs of wet oxidation systems are presented in
Table 38 for the animal confinement units that have been assumed
in this report.
Land Disposal—As noted in Part 6, wastes can be disposed of
on the land in a variety of ways; thin spreading, subsoil injection,
and spraying. Optimum application rates and associated costs are
not available. Comparative land areas needed for these three methods
are indicated in Table 39.
-------
135
Hart (100) suggested a rate of 200 ft2 per cow and 1 ft2 per
chicken for drying of their manures on the land. On a dry solids
basis, a hog produces about one-tenth that produced by cattle
(Table 35). The land area need for thin drying of hog manure was
2
estimated at 20 ft per hog or one-tenth that for a cow.
Only two articles describing subsoil injection of animal wastes
appear in the literature. One (101) indicates a rate of 200 tons
of wet solids per acre may be possible. The other (122) indicates
that a lower rate, 0.25 ton per acre was successful. Two rates,
10 and 100 tons per acre, were used for the estimates (Table 35).
Spraying of the waste is a possibility. Rates from 1/3 to
1 inch per acre have been successful with dilute animal wastes
(106). The flow values indicated in Table 35 were used to estimate
the needed land area. Animal manures in the volumes noted would
not be dilute and a lower application rate, 0.05 inch per acre,
was also used to estimate the land area needed. Additional
acreage will be needed since the land will have to be rested
periodically to absorb the sprayed wastes. Spraying cycles of
once every three to four days have been found beneficial in certain
areas,
Evaluation of Compared Processes
Considerable liberty has been taken in developing the size
and cost relationships presented in Tables 36-39. The waste
production values per animal, and the design criteria used were
selected by the author based upon his experience and his estimation
-------
136
that the values and criteria were possible and realistic. It should
be stressed that the relationships shown in Tables 36-39 should not
be used as if they were actual design sizes and costs. The relation-
ships are based upon quite arbitrary values. In many cases, perhaps
only one or two pieces of data were available for evaluation and
estimation. In other cases, data obtained for the treatment, handling,
and disposal of nonanimal wastes were used to estimate relationships
for animal wastes.
The processes selected for treatment and disposal of animal
wastes are not all-inclusive nor have all factors inherent in a
specific process been included. Processes such as sanitary landfill,
dehydration, incorporation of animal wastes as feed for other animals,
pyrolysis, and others yet to be developed may be more suitable. With
the exception of an anaerobic-aerobic system, each process has been
evaluated as if it were the sole process. This will not happen in
actual practice. Ultimate solids disposal must be accomplished with
every process whether it be biological such as anerobic digestion or
physical such as incineration. Many alternative systems are possible,
such as lagoons followed by separate land disposal of the liquid and
the solids and incineration followed by land disposal of the ash.
Factors not incorporated in the size and cost estimations include:
(a) handling and transportation from the confinement operations to the
site of treatment or disposal; this can be a significant cost due to
the quantity of waste involved, (b) pollution abatement and control
equipment and procedures such as air pollution control when handling
-------
137
dry solids; nuisance control, e.g., odors and noise; and land use
control to prevent subsequent ground and surface water pollution
if land disposal is practiced; (c) further treatment of the liquid
portion of certain processes such as possible tertiary processes
following aerobic treatment, and processes to treat the liquid
resulting from wet scurbbing devices for air pollution control;
(d) manpower involved to oversee, maintain, and operate suitable
facilities, and (e) ultimate solids disposal from most of the
processes.
Even if a suitable system is available for the treatment of
the waste from animal confinement operations, consideration also
should be given to control of runoff when animals are housed in
the open. The runoff contaminates receiving waters and should
be controlled. A system for handling this liquid will be
necessary but has not been evaluated in this report.
While the information in Tables 36-39 cannot be used in a
definite sense, it can be used to shed light on processes that
appear to have unexplored potential for animal waste treatment
and to indicate where additional work would be valuable. The
size (Table 40) and costs (Table 41) of possible treatment and
disposal processes have been compared.
Comparisons were made on the basis of surface area for those
processes requiring relatively large land areas but comparatively
little operation, maintenance, and construction costs and on the
basis of annual cost for those processes requiring small land area
-------
TABLE 40
SIZE OF POSSIBLE TREATMENT UNITS—SUMMARY COMPARISON*
Surface Area (.acres)
Oxidation Pond
Oxidation Ditch
Anaerobic Lagoon
200 Ib. VS/1000
/day
50 Ib. VS/1000 ft/day
Combined System - Total Area
Anaerobic Lagoon plus
Oxidation Pond
Anaerobic Lagoon plus
Oxidation Ditch
Land Disposal
Thin Spreading
Sub- soil Injection
100 tons/acre
10 tons /acre
Spraying
,05"/dcre
Dairy
Cattle
33
.0-29
0*09
0,37
16.9
0,51
4,6
0.35
3,5
Beef
Cattle
33
0,29
0.09
0,37
16,, 9
0,51
4,6
0,30
3,0
Hogs
10
0,04
0,008
0,033
5,03
0,053
0,46
0.02
0=2
Chickens
0.5
0,0057
0,0005
0.0022
0.252
0.0051
0.023
0.0013
0.013
7,3
3.7
0.73
>Based on 1000 animal per type of confinement unit and arbitrary assumptions made in
Part 7 of the report,
oo
-------
TABLE 41
COST OF POSSIBLE TREATMENT UNITS-SUMMARY COMPARISON*
Dairy Beef
Cattle Cattle Hoas Chickens
Animal Cost (dollars per year)
High Rate Anaerobic
Digestion(0.2 Ib. VS/ft3/day) $18,200 $18,200 $1,650 $110
Wet Oxidation
High Pressure $18,200 $18,200 $1,650 $110
Low Pressure $ 5,500 $ 5,500 $ 660 $ 44
Incineration $9,100 $ 9,100 $ 825 $ 55
Composting $9,100 $9,100 $825 $ 55
*Based on 1000 animals per type of confinement unit and arbitrary assumptions
made in Part 7 of the report.
u>
VD
-------
140
but comparatively large construction and operational costs. Although
some data on construction costs for a few processes are included in
Tables 38 and 39, sufficient information was not available to compare
construction costs for all processes evaluated.
On a comparative basis of 1,000 animals per confinement unit, it
is obvious that the treatment and disposal of cattle wastes will be
more expensive and require more land area than will the treatment and
disposal of wastes from other animals. This was to be expected because
of the quantity of waste excreted from each animal (Table 35). However,
confinement chicken operations frequently house from 100,000 to 1,000,000
birds. Treatment and disposal costs for units of such size will be
comparable to smaller confinement units feeding larger animals. Beef
cattle feedlots are reaching capacities of 10,000 and more head. Con-
siderable construction and annual costs as well as land area will be
involved for suitable treatment and disposal from such operations.
Unit costs per animal or per animal capacity of confinement area will
be in relation to the quantity of wastes defecated per animal (Table
35) and to the processes used (Tables 40-41).
Experience with other wastes indicates that oxidation ponds can
cost the least. The large land areas needed for this process are
obvious (Table 40). Supplemental water will be necessary to maintain
a proper water balance in the pond. Where suitable land is not avail-
able, other methods of waste treatment are necessary. Mechanical
aeration, such as accomplished by the oxidation ditch can reduce the
-------
141
needed land area drastically (Table 40). Large power demands will
be necessary for the aeration equipment (Table 36) and will prove a
significant expense.
An anaerobic lagoon will reduce the load and hence size of
subsequent aerobic units. Disposal of residual solids, probably
on the land, will be necessary.
Although the land area needed for subsoil injection of wastes
was estimated from fragmentary information, this method appears to
have potential as an ultimate disposal method if the rate is greater
than 10 tons per acre. Not only are smaller land areas necessary than
for thin spreading and spraying but subsoil injection appears to be
a complete disposal method and one that will cause little secondary
pollution of surface waters. Pollution of ground waters is possible.
Subsoil injection has the greatest potential when the wastes are not
diluted excessivelyo
High rate anaerobic digestion and high pressure wet oxidation
appear to cost more than low pressure wet oxidation, incineration,
and composting. It is unlikely that complex processes, such as high
rate anaerobic digestion and high pressure wet oxidation, processes that
require large capital and annual costs as well as suitable operating
personnel, will be feasible for animal confinement operations at the
present time.
Another insight into the costs of solids disposal can be obtained
from the estimated costs of activated sludge disposal at the Chicago
Sanitary District (Table 42). Disposal of the solids on the land is the
least cost solution.
-------
142
TABLE 42
COSTS FOR DISPOSAL OF ACTIVATED SLUDGE
(CHICAGO SANITARY DISTRICT) (140)
$/dry ton
Drying and sales as fertilizer $60
Zimmerman process 50
Dewatering and incineration 57
Digestion and permanent lagoon 50
Digestion and reclamation of farm land 15
Digestion and reclamation of strip mines 16
Summary
There is a significant lack of usable data for evaluating the
economics of animal confinement units and of treatment and disposal
facilities for such units. The income from animal production opera-
tions has either decreased or stayed the same in recent years although
the general cost of living continually has increased. This squeeze in
costs has caused an increasing trend toward confinement feeding operations.
This trend will increase in the future. The corporation type animal
production operation will occur with the larger animals as it has
occurred with the egg and broiler production industry. Confinement
feeding operations emphasize and accelerate the need for satisfactory
waste treatment and disposal.
Size and costs for a number of treatment processes were explored.
There is no single process that is satisfactory. Combinations of
processes will be necessary to meet the needs of specific operations
and locations. Consideration must be given to the effect of animal
-------
143
management and waste handling systems on the waste treatment and
disposal system. Since the wastes originate as semisolid material,
it may be better to handle and dispose of the wastes as a semisolid
rather than increase the volume to be handled and process it as
a liquid slurry. Some farmers have shown a preference for handling
the waste as a slurry, however,.
Both liquid and solid disposal methods appear to be needed.
From the size and cost standpoint, simple anaerobic units, mechanical
or diffused aeration systems, simplified incineration units, low
pressure wet oxidation, and sub-soil injection of wastes should be
explored as potential processes for animal waste treatment and
disposal. The author believes these processes should be given high
priorities for research and field demonstration investigative studies.
There is an almost complete lack of cost information relating
to animal waste treatment processes. It is imperative that all
research studies collect and report information that can be used
to estimate the cost of the various processes. Laboratory studies
will be necessary to delineate feasible processes. Field studies
on as large a scale as possible should follow as quickly as possible
to determine the performance of the processes when exposed to the
vagaries of environmental conditions and waste management practices.
All such projects should include the collection of detailed cost
as well as performance data so that the process can be adequately
evaluated.
-------
144
As more and better design and cost information becomes available,
the estimates presented in Tables 40 and 41 can be re-evaluated to
be more realistic.
-------
PART _8
LEGAL
Federal
The Congress of the United States has been developing a
Federal water pollution control program since the turn of the
century, but with increasing effect and rapidity since 1948.
The basic policy and philosophy of water pollution control in
this country can be found in the Water Pollution Control Act of
1948 and subsequent legislation enacted in 1956, 1961, 1965, and
1966. The basic policy includes the following: (1) Congress
has the authority to exercise control of pollution in the water-
ways of the nation, (2) both health and welfare are benefited
by the prevention and control of water pollution, (3) Congress
has no intent of divesting either the states or the Federal
government of authority to prevent or control water pollution, and
(4) a national policy for the prevention, control, and abatement
of water pollution shall be established (137).
The legislation covers all forms of pollution irrespective
of its source. Certain types of pollution have been classified
as "natural" or "background" pollution. "Natural" pollution can
come from a number of sources such as runoff from urban, rural,
and forest lands, natural chloride seeps, decaying vegetation
such as leaves and crop residue, and animals on pasture and
grazing lands. Such pollution is difficult to control because
of its diverse nature, lack of controllable point sources, and
145
-------
146
inadequate knowledge concerning feasible collection and treatment
techniques. Also it has been assumed that this type of pollution
not only is uncontrollable but is of small significance compared
to municipal and industrial wastewaters.
Recent developments in animal production techniques have
altered the traditional concept of including pollution from
animal wastes as "background" or uncontrollable pollution. About
one-half of the wastes from livestock remain on pasture and uncul-
tivated land. The wastes from the remainder accumulate in pens,
feedlots, and loafing areas. Increased automation and efficiency
of crop use are expected to increase the latter fraction. Animal
wastes can cause serious pollution as has been noted in Part 5 of
this report.
The Federal Government has the authority to control and abate
the pollution caused by animal wastes. This authority should be
exercised as needed. Farmers and ranchers should recognize that
drainage from feedlots, farmsteads, and fields is clearly pollutional
if such drainage contributes material objectionable to the water use
of others. The fact that agriculture can cause pollution must be
recognized and acknowledged by the agricultural community.
State
Kansas is one of the first States in the country adopting regu-
lations for the control of water pollutants from animal feedlot
operations. The regulations stipulate that, effective July 1,
1967, the operator of any newly proposed confined feeding operation
-------
147
of 300 or more animals or an operation using waste ponds or lagoons
must register with the Kansas State Department of Health prior to
construction and operation of the facilities. The operator of any
existing confined feeding operation having 300 or more animals must
register by January 1, 1968. If in the judgment of the Department
a proposed or existing confined feeding operation does not constitute
a water pollution problem, provision of water pollution control
facilities will not be required. If such a confined feeding opera-
tion does constitute a water pollution potential or if water pollution
occurs as a result of the operation, the operator shall provide water
pollution control facilities constructed in accordance with plans and
specifications approved by the Department. A permit is required for
water pollution control facilities and is granted subject to continual
and satisfactory operation of the pollution control facilities.
The minimum water pollution control facilities for confined
feeding of cattle, swine, and sheep are stated as retention ponds
capable of containing three inches of surface runoff from the confined
feeding area and all other waste contributing areas. Each confined
feeding operation will be reviewed and evaluated on its own merits.
Construction of runoff retention ponds will greatly relieve
surface water pollution during and following rains. Laboratory
and field studies have indicated that the effluent from such ponds
may not meet the requirements for discharge into a receiving stream.
Subsequent treatment of the pond effluent or other forms of waste
treatment may be necessary to protect the water resources of an area.
-------
148
Modifications of the Kansas regulations are being considered
in other livestock producing States. Such regulations are a needed
step in the right direction and will need to be altered as additional
economically feasible treatment procedures become known and available.
Local
In addition to State and Federal pollution control programs,
public health nuisances of confined feeding operations can be abated
at the local level by either city or county governments. As an
example, Kansas statutes indicate that regulations providing minimum
standards for location, construction, and operation of such facilities
can be promulgated by cities and are applicable within five miles of
the corporate limits.
It is unlikely that local legislation will be very effective,
Many feeding operations are more than five miles from any city.
Other feeding operations are adjacent to small cities that will
hesitate to enforce legislation that may move a thriving enterprise
from their area. Control and abatement programs on the state and
Federal levels will be more successful.
Great Britain
A variety of legislation relevant to river pollution in Great
Britain has been enacted over the centuries (138). The Public
Health Acts of 1937, 1951, and 1961 are the most pertinent to the
problem of agricultural wastes. The 1937 Act regulated the admission
of trade effluents to sewers and exempted those discharges made prior
to the Act. The 1951 Act defined the term "trade effluent" to exclude
-------
149
domestic sewage and any liquid discharged from any land or premises,
wholly or mainly used (whether for profit or not) for agricultural
or horticultural purposes and from scientific research or experimental
areas.
Under such definitive type of legislation, agricultural wastes
were excluded from governmental control. The Public Health Act of
1961 removed the exemption on pre-1937 discharges and enabled local
authorities to levy charges and impose conditions of discharge on
them. Certain effluents excluded by the Act of 1951 from the defini-
tion of trade effluents were included. As a result of the 1961 Act,
farm effluents are now regarded as trade effluents and their reception
into a sewer may now be sdbject to conditions imposed by the local
authorities, even though they may have been so discharged for a long
time.
June 1, 1963 was the day upon which the discharge of farm
effluent into any watercourses became illegal in England. The
effluent from farms must either be retained on the farm or cleaned
to a standard considered satisfactory by a river board. The legis-
lation has had a significant effect in reducing pollution from farm
effluents. Some farmers have ceased to discharge effluents and have
made arrangements to dispose of their waste on the land. Others are
separating uncontaminated surface and roof water and are spreading
only wastewater on land. A few farmers have installed treatment
plants.
-------
150
S ummary
Animal wastes and farm effluents have polluted surface and
ground waters. The increasing trend toward confined animal feeding
will magnify these problems. Authority for the abatement and control
of pollution from agricultural sources exists within the Federal
government although it has not been used in a specific case.
States are awakening to the need to provide adequate regulations
concerning the disposal of animal wastes. The efforts of both
Federal and state authorities should be increased.
It will be necessary to supplement and parallel any regula-
tory and enforcement activity with a planned educational program and
a productive research program. The educational program is needed
to alert the public and the agricultural community to the need for
adequate treatment and disposal of all agricultural wastes. The
research program is needed to develop and demonstrate economically
feasible treatment and disposal methods that can be used with
animal wastes.
The achievement in England, accomplished by better regulatory
control and by continuing education and research, can be duplicated
and exceeded in the United States. The problem of agricultural
wastes requires acknowledgment by the public coupled with an
aggressive and enthusiastic regulatory and research program.
-------
FART 2
SUMMARY AND RECOMMENDATIONS
Summary
Agriculture is the biggest producer of wastes in the United
States. Animal wastes constitute one of six sources of farm wastes
whose management and disposal have become one of the most challenging
problems of modern farming. Three pounds of manure are defecated
for every quart of milk produced. Six to 25 pounds of manure are
produced per pound of weight gain for livestock. While some of
this is left in pasture and rangeland, about one-half of it is
desposited in feedlots, barns, and other animal production units
from whence it must be removed for disposal. The future will see
a greater increase in confinement feeding of animals with an increas-
ing need for better waste treatment and disposal procedures.
Although disposal of animal wastes has been a nuisance to the
animal producer, only recently has it been recognized as a potential
national problem. Within the last few years agricultural experiment
stations and Federal agencies such as the Departments of Agriculture,
Interior, and Health, Education, and Welfare have begun to support
research in farm wastes management.
The animal waste problem results from problems in treating and
disposing of animal wastes, in their management, or both. There is
little current information to assist in solving these problems. That
which is available is scattered in diverse publications and not in a
form that is readily useful to the farmer or animal producer.
151
-------
152
Few efforts have been made to coordinate all or even most of the
pertinent factors having an impact on the solution within a particular
study. Suitable solutions to the animal waste problems require iden-
tification and analysis of the properties of the wastes, handling
procedures, treatment techniques, utilization methods, and ultimate
disposal. There is a significant need for an integrated interdisci-
plinary approach that involves all the above factors. The approach
should be initiated and developed by the professionals in the
appropriate disciplines and not primarily by the apprentices or
the graduate students,
Confinement production of livestock and poultry results in
large volumes of accumulated animal excreta and associated feed,
water, and bedding or litter. Concentrated animal wastes are
potential sources of undesirable pollution to ground and surface
waters until they are incorporated with the soil. A number of
cases of serious surface and ground water pollution have been
documented. Pollution of ground water within a localized area is
highly probable whenever accumulations of animal wastes are stored
on or below the ground unless stored in water tight structures,
Rural runoff water must be considered as a factor in water pollution
control problems because sizable organic and inorganic loads are
discharged to the receiving stream over short periods of time.
Historically, most animal wastes have been recycled through
the soil with a minimum of direct release to receiving waters.
This is not possible in as many instances as it once was due to
-------
153
the trend toward confined animal production operations. The animal
producer finds himself with large volumes of wastes that have low
value and physical and/or economic restrictions which limit the
feasibility of recycling animal wastes through the soil environment.
There are no simple solutions to the problem. Past failures
have occurred because of a lack of understanding of the waste charac-
teristics, a lack of understanding concerning suitable treatment,
disposal, and management methods, a lack of appreciation in many
areas that a problem existed, and a general feeling that treatment,
disposal, and management methods should produce a profit or cost
very little. Emphasis has been on cheapness rather than adequacy
of method.
The principal approaches that should be taken are a program
of research to determine economically and technologically feasible
methods of animal waste treatment and disposal and a program of
education of the public and the waste producer on the need for
solutions to the problem of animal wastes. A comprehensive
program of integrated waste management is necessary. Solutions
will come when coordinated systems are developed that will obtain
the desired level of sanitation and the public is convinced of the
necessity of paying for it.
In these days, there is no longer any way an individual sector
of society can dispose of wastes by simple export. Ultimate disposal
of most of the stabilized material will have to be on agricultural
lands. Treated waste material will not be able to compete with
-------
154
commercial fertilizers. Encouraging the farmer to use the treated
wastes may require that it be given to him at a cost below the
actual cost of stabilizing it.
Agriculture has differed from other industries. In some areas
the profit margin has been maintained at what was considered a
reasonable level, Large-scale increases in production costs can
only be met by another form of subsidy or by increasing the cost
of the product to the consumer directly.
The public must understand that waste disposal, including
that from animals, is worth whatever it costs within the framework
of sound administration and engineering. The cost is part of the
price that must be paid for our high standard of living.
Recommendations
Additional summary material has been presented in each part
of this report. The following recommendations result from both
the body of the report and the summaries* It should be noted that
the recommendations are not presented in any order of priority. A
flow sheet itemizing these recommendations (Figure 12) concludes
this Part.
(1) The population increase in the nation and the increase
in per capita consumption of meat will cause greater numbers of
animals, especially cattle and broiler chickens, to be raised.
Livestock feeding operations will increase throughout the nation
both in number of units and the number of animals per unit. The
-------
L55
problems associated with the handling, treatment, and disposal of
wastes from these units will be magnified in the future.
It is recommended that objectives be set with regard to acceptable
degrees of treatment and disposal to control the problems that will
result from indiscriminate discard of animal wastes into the environ-
ment. Adequate education, research, development, and training
concerning these problems and their solutions should be given high
priority.
(2) Pollution caused by wastes from animal production facilities
can be as detrimental to the environment as wastes from any other
industry. Many animal production facilities have been developed
with little planning and concern for the nuisance and pollutional
characteristics inherent in the facilities.
It is recommended that future research and educational activities
dealing with animal wastes develop and emphasize the interrelationships
of animal handling and production operations and waste management
operations, such as waste handling, treatment, and disposal operations,
to eliminate pollution from animal production facilities.
(3) Research activities on animal waste management to date (1967),
have been closely allied with training activities and have resulted
from master or doctoral research.
It is recommended that future training activities be separated
from research activities. Training activities should not be the source
of the major research activity in animal waste control and abatement,
-------
156
(4) Educational and training activities are vital to a success-
ful attack on the animal waste problem, Activities should not only
be geared to the education and training of professional people
capable of attacking the problem but they should be geared also to
educating the general public and the agricultural community that
there is a problem, the magnitude of the problem, and the costs of
its solution.
Formal training takes a relatively long time to produce
qualified professional people capable of attacking a problem*
A reservoir of competent sanitary engineers, agricultural engineers,
economists, agronomists, and other professionals trained in various
aspects of agriculture and waste management exists in this country,
Other than their own specialties, few of these individuals have the
knowledge that is needed to understand and solve the complexities
of animal waste control and abatement.
It is recommended that educational and training activities
aimed at the control and abatement of animal waste pollution include;
(1) formal training and education to produce professional people
capable of solving the problem, (2) education of the general public
and the agricultural community to the magnitude and costs of the
problem, (3) opportunities such as senior fellowships at qualified
educational institutions and in governmental organizations to broaden
the background, training, and experience of professionals competent
in only one aspect of animal waste control and abatement, and (4)
workshops at all levels to disseminate information concerning the
problem and proper techniques for its solution.
-------
157
(5) There is a wide divergence of data on the characteristics of
animal wastes. This divergence results from differences in housing
and management practices, in types of ration fed, from the analytical
techniques employed, and from waste handling and collection techniques.
Probably no single study of animal waste characteristics would be as
valuable as information obtained from a number of independent investi-
gations conducted under widely varying conditions,;
It would be valuable.to have a detailed study of the applicability
of the traditional physical, chemical, and biological analytical
techniques to animal wastes since these techniques were developed
primarily for liquid wastes. Modification of current analytical
techniques may be desirable and necessary.
It is recommended that all projects conducting research on
animal waste control and abatement collect data on the characteristics
of the wastes used in the project. Information concerning housing
and management practices, rations fed. and waste handling and
collection practices used in the project also should be reported,
It is recommended that a detailed study be initiated to delineate
the proper analytical techniques to be used with animal wastes. Proper
techniques for accurate determination of waste characteristics, per-
formance of treatment facilities, and quality of resultant effluents
are needed.
(6) Many treatment systems are possible. Few have been evalu-
ated closely to obtain pertinent loading, performance, effluent
quality, and cost data. Information is needed on the effect of
-------
153
seasonal temperature variations and loading conditions. Both solid
and liquid handling, treatment, and disposal systems are feasible
and should be investigated. No one treatment process or system will
be the solution for all animal production units, A variety of manage-
ment and treatment systems will have to be developed.
It is recommended that coordinated, interdisciplinary research
activities be initiated to: (a) investigate all possible animal
waste treatment processes, (b) develop new processes for waste
handling, treatment, and disposal, ^c) provide information on
processes for both solid and liquid handling and treatment of the
wastes, (d) determine how these processes interact with animal
production operations, ^e) provide detailed data on the quality
of the solid, liquid, and gaseous material, if any, that result
from these processes, vf) itemize the construction, maintenance,
and personnel costs associated with the processes, (g) investigate
better control of the wastes at the source, i.e., the animal, and
(h) delineate possible treatment systems that may be used to meet
the control and abatement objectives of a region and/or the nation,
(7) Conventional physical, chemical, and biological treatment
processes can effectively remove over 90/f, of the solids and oxygen
demanding material in the untreated animal wastes. Effluents from
such processes still may not be suitable for discharge to streams,
not only because of remaining solids and oxygen demanding material
but also because of detrimental nitrogen, phosphorus, chloride,-and
trace metal concentrations. The color of the effluent may also be
a problem.
-------
159
It is recommended that research be conducted on the effluents
of processes used to treat animal wastes to: (a) determine possible
detrimental concentrations of material such as nitrogen, phosphorus,
chlorides, color, and other factors that could prevent the effluents
from being discharged or reused, (b) develop suitable tertiary processes
and systems to allow the effluents to be discharged or reused, and
(c) determine the possible effect of secondary and tertiary effluents
on receiving surface and ground waters and in possible reuse systems.
(8) The ultimate disposal of treated and untreated solids remains
unsolved. The traditional approach has been to consider the land as
a disposal "sink" for residual waste solids and liquids. There is
considerable doubt that this can be sustained on a long term basis.
While investigations will continue on the quantity and quality of
liquids and solids that can be disposed of on the land, investiga-
tion of other ultimate disposal techniques, such as incineration,
wet oxidation, and reuse deserve attention.
It is recommended that considerable emphasis be given to the
assessment of feasible ultimate disposal techniques for untreated
solids and liquids as well as for the residues from waste treatment
processes. These techniques should be integrated with feasible
handling and treatment processes to develop over-all waste control
and abatement systems.
(9) The increase in the number of large scale animal production
facilities and the number of animals per facility has resulted from the
fact that income from animal production operations has either decreased
-------
160
or stayed the same while the cost of living has increased. There is
almost a complete lack of cost information relating to animal waste
treatment processes and systems. It is imperative that all research
studies collect and report information that can be used to estimate
the cost of feasible systems. Field studies on as large a scale as
possible are valuable not only to determine performance under actual
environmental conditions but to obtain realistic data on the cost of
such systems.
It is recommended that all animal waste research and develop-
mental projects be oriented to obtain cost data to evaluate potential
treatment and abatement systems. Economic studies should be conducted
to evaluate: (a) the effect of the costs of waste control and abate-
ment on the costs of animal production, (b) the effect of the costs
of animal production on the costs of waste control and abatement,
(c) the costs that will ultimately be borne by the consumer, and
(d) the need for subsidies to insure adequate animal waste control
and abatement.
(10) Recent accomplishments in controlling pollution from
agricultural sources in England have occurred because of better
regulatory control and continuing education and research. These
achievements can be duplicated and exceeded in the United States.
Wastes from animal production facilities should not be classified
as "uncontrollable" or "natural."
It is recommended that large scale animal production facilities
be considered as individual industries, and that they be considered
-------
161
subject to State and Federal regulations concerning pollution abate-
ment. Current Federal and State regulations should be reviewed to
ensure that they adequately cover pollution caused by animal production
facilities.
(11) Developments in the control and abatement of animal wastes
are in a state of flux. These wastes were not significant less than
two decades ago. Because of the rapid increase in confinement feeding
facilities, they have become a major source of pollution in certain
parts of the country. Research, developmental, and educational efforts
are only now getting underway. These efforts will be increased in the
future.
It is recommended that a forward oriented review be conducted in
five years to assess the developments in that time and to develop
directions for the future.
-------
FIGURE 12
RECOMMENDED ACTIVITIES FOR ANIMAL WASTE
CONTROL AND ABATEMENT
DEVELOPMENTAL
RESEARCH
1) Economics of Waste
Control
a) effect on the na-
tional economy
b) need for subsidy
c) effect on costs of
animal production
d) interrelationships
of animal waste manage-
ment systems
2) Handling Processes and
Systems
a) liquid and solid
wastes
b) treated and un-
treated wastes
c) cost and management
studies
"•*•
3) Treatment Processes
and Systems
a) liquid and solid
wastes
ANIMAL WASTES
FIELD RESEARCH
AND DEVELOPMENT
1) Land Disposal Studies
a) for total disposal
b) for crop response
c) potential ground and
surface water pollution
d) seasonal, soil, crop
variation
e) treated and untreated
wastes
f) cost studies
2) Animal Management Studies
a) effect of waste manage-
ment
b) changes in confine-
ment feeding operatings
and effect on waste man-
agement
c) effect of rations on
waste production
d) source control
EDUCATION
1) Formal Education and
Training
a) M.S. level
b) Ph.D. level
2) Senior Fellowships
a) for professionals in
other disciplines
3) Workshops
a) dissemination of infor-
mation
4) General Public
a) magnitude of the problem
b) cost of the problem
5) Agricultural Community
a) magnitude and cost of
the problem
b) potential and feasible
control and abatement
systems
-------
b) loadings, perform-
ance, effluent quality
c) aerobic, anaerobic,
tertiary
d) co=i; studies
4) Effect of Effluents
and Solid Residues
on the Environment
a) surface and ground
water effect
b) potential reuse
5) Ultimate Disposal
a) treated and untreated
wastes
b) incineration
c) landfill
d) wet oxidation
e) reuse
f) land disposal
g) cost studies
6) Documentation of Pol-
lutions
a) short range effect in
streams
b) long range effects
in reservoirs, lakes
c) data on all pol*
lutional parameters
FIGURE 12--(Continued)
3) E ffect on Environment
a) treated and untreated
wastes
b) surface and ground
water
c) odors, nuisances
4) Reuse
a) treated and untreated
waste as animal feed
b) water reuse
5) Demonstration Projects
a) feasibility and cost
evaluations of systems
investigated in the de-
velopmental projects
6) Operating Personnel
a) education of those who
will operate and maintain
the feasible control and
abatement systems
-------
FIGURE 12--(Continued)
7) Waste Characteristics
a) included in each
project
b) effect of animal
management techniques
c) effect of waste
collection and hand-
ling
8) Development of Ana-
lytical Techniques.
a) for liquid wastes
b) for solid wastes
-------
REFERENCES
Articles marked with an asterisk are recommended for individuals
who have very little background in the subject but wish to become
fairly knowledgeable in a short period of time.
1. Schleusner, P. E. "Research Needs in Rural Waste Utilization,"
Agric, Engr. , 492-495, Sept. 1964.
2. U. S. Department of Agriculture. "National Food Situation,"
May 1967.
3. U. S. Department of Agriculture. "Agricultural Statistics—
1966," U. S. Gov. Printing Office.
4. Anon. "Beef Production in 1970," Wallaces Farmer, 8J7, 18,
Dec. 1, 1962.
5. Anon. "World Cattle Numbers Reach New High of over 1 Billion
Head," Foreign Agriculture 3, 4, June 14, 1965.
6. Kansas Crops and Livestock Reporting Service. U. S. Dept.
cf Agriculture, Statistical Reporting Service, Topeka,
Kansas.
*7. Loehr, R. C. and Agnew, R. W. "Cattle Wastes—Pollution
and Potential Treatment," Jour. San. Eng. Div. ASCE 93
SA4, 72-91, 1967.
8. Anon. "Cattle Cycle," Amer. Cattle Producer 44,, 18,
Feb. 1963,
9. U. S. Department of the Interior. "Pacific Northwest
Economic Base Study for Power Markets—Agricultural and
Food Processing," Vol II, Part 5, Bonneville Power
Administration, 1966.
10. Logan, S. H. and King, G. A. "A Study of Structural
Aspects- Beef Cattle Feeding and Slaughtering in
California," Univ. of Calif. Agr. Exp. Stat. Bui. No. 826,
Aug. 1966,
11 U S Department of Agriculture. "Number of Feedlots by
Size Groups and Numbers of Fed Cattle Marketed, 1962-64,"
Statistical Reporting Service, SRS-9, June 1966.
165
-------
166
12. Hart, S. A and McGauhey, P. H. "Wastes Management in the Food
Producing and Processing Industries," llth Pac. Northwest Ind.
Wastes Conf., Corvallis, Oregon, 1963.
13. Blosser, T H. "The Changing Picture in Animal Production,"
Proc. Pac. Northwest Animal Industry Conf.15-20, Pullman,
Wash., 1964.
14. U. S. Department of Agriculture. Soils and Men Yearbook of
Agriculture, 448-50, 1938.
15. Morrison, F. B. Feeds and Feeding. 22nd Ed., The Morrison
Publishing Co., Clinton, Iowa, 1959.
16. Taiganides, E. P. and Hazen, T. E. "Properties of Farm Animal
Excreta." Trans. ASAE 9. 374,376, 1966.
17. Hart, S. A. "The Management of Livestock Manure," Trans. ASAE 3,
78-80, 1960.
18. Cassell, E. A. and Anthonisen, A. "Studies on Chicken Manure
Disposal: Part I, Laboratory Studies," Research Rept. No. 12,
New York State Department of Health, 1966.
*19. Morris, W. H. M. "Economics of Liquid Manure Disposal from
Confined Livestock," Proc. Nat. Symp. Animal Waste Management,
ASAE Pub No. SP-0366, 126-131, 1966.
20. Baines, S. "Some Aspects of the Disposal and Utilization of
Farm Wastes," J_- Proc. Inst. Sew. Purif. 578-588, 1964.
21. Benne, E. J., Hogland, C. R., Longnecker, E. D., and Cook, R. L.
"Animal Manures—What are they Worth Today?" Agric. Exp.
Stat. Mich. State Univ. Bui. No. 231, 1961.
22. Culpin, C. "Equipment for Disposal of Agricultural Effluents,"
Chem. & Ind., 350-353, Feb. 29, 1964.
23. Wolf, D. C. "Developments in Hog Manure Disposal," Trans. ASAE
jj 108-109, 1965.
*24. Taiganides, E. P., Hazen, T. E., Bauman, E. R., and Johnson, D.
"Properties and Pumping Characteristics of Hog Wastes," Trans.
ASAE 7, 123, 1964.
25. Dale, A. C. and Day, D. L. "Some Aerobic Decomposition Properties
of Dairy Cattle Manure," presented at the ASAE Winter meeting,
Chicago, 1966.
-------
167
26. Sobel, A- T. and Guest, R. W. "Comments on Liquid Handling
of Dairy Manure," Dept. of Agric. Engr., Cornell Univ., Jan.
1965.
27. Sobel, A. T. "Some Physical Properties of Animal Manures
Associated with Handling," Proc. Nat. Symp. Animal Waste
Management. ASAE Pub. No. SP-0366, 27-32, 1966.
28. Perkins, H. F-, Parker, M. B. , and Walker, M. L. "Chicken
Manure — Its Production, Composition, and Use as a Fertilizer,"
Georgia Agric. Exp. Stat. Bui. NS123, 1964.
29. Papanos, S. and Brown, B. A. "Poultry Manure," Connecticut
Agric. Exp. Stat. Bui. 272, 1950.
30. Dornbush, J. N. and Anderson, J. R. "Lagooning of Livestock
in South Dakota, Proc. 19th Ind. Waste Conf.. Purdue Univ.
317-325, 1964.
31. Hart, S. A. and Turner, M. E. "Lagoons for Livestock Manure,"
JWPCF 37, 1578-1596, 1965.
32 Clark, C. E. "Hog Waste Disposal by Lagooning," Jour. San.
Eng. Div. ASCE 91, SA6, 27-42, 1965.
*33 Jeffrey, E. A., Blackman, W. C., and Ricketts, R. L. "Aerobic
and Anaerobic Digestion Characteristics of Livestock Wastes,"
Engr. Series Bull. No. 57, Univ. of Missouri, 1963.
34 Witzel, S. A., McCoy, E., Polkowski, L. B., Attoe, 0. J., and
Nichols, M. S. "Physical, Chemical and Bacteriological
Properties of Farm Wastes (Bovine Animals)," Proc. Nat. Syrm?.
Animal Wastes Management, ASAE Pub. No. SP-0366, 10-14, 1966.
35 Little F J. "Agriculture and the Prevention of River Pollution
as Experienced in the West of Scotland," J. Proc. Inst. Sew.
Purif., 452-454, 1966.
36 Federal Water Pollution Control Administration. "Report on
Pollution of the Navigable Water of Moriches Bay and Eastern
Section of Great South Bay, Long Island, New York," Metuchen,
New Jersey, Sept. 1964.
37. Hart, S. A. "Digestion Tests of Livestock Wastes," JWPCF 35,
748-757, 1963.
38. Niles, C. F. "Egg Laying House Wastes," presented at the 22nd
Purdue Ind. Wastes Treat. Conf., 1967.
-------
168
39. Scheltinga, H. M. J. "Aerobic Purification of Farm Waste,"
J_. Proc. Inst. Sew. Purif. , 585-588, 1966.
40. Irgens, R. L. and Day, D. L. "Laboratory Studies of Aerobic
Stabilization of Swine Wastes," J_. Agric. Eng. Res. , 11, 1-10,
1966.
41. Poelma, H. R. "The Biological Breakdown of Pig Urine," Bui. No. 18,
Inst. for Farm Buildings, Wageningen, Netherlands, 1966.
*42. Anon. Water Pollution Research--1963. Dept. of Scientific
and Indust. Research, HMSO, 73-77, 1964.
*43. Anon. Water Pollution Research--1964. Ministry of Technology,
HMSO, 103-108, 1965.
*44. Ruf, J, A. "Anaerobic Lagoon Treatment of Milking Parlor
Wastes," M.S. Thesis, Univ. of Kansas, 1966.
45. Henderson, J. M. "Agricultural Land Drainage and Stream
Pollution," Jour. San. Engr. Div. ASCE 88 SA6, 61-73, 1962.
46. Hart, S. A. "Fowl Fecal Facts," Nat. Symp. on Poultry Ind.
Wastes, Lincoln, Nebr., May 1963.
47. Anon. "Population Equivalent of Chickens," Public Works,
p. 156, July 1966.
48. Fair, G. M. and Geyer, J. C. Water Supply and Wastewater
Disposal, p. 563, Wiley, 1954.
49. Task Group 2610P. "Sources of Nitrogen and Phosphorus in
Water Supplies," JAWWA 59, 344-366, 1967.
50. Young, G. E. "Agriculture's Responsibilities and Opportunities
to Ensure Clean Water," presented at the International Conference
on Water for Peace, Washington, D.C., 1967.
51. Loehr, R. C. "Municipal and Agricultural Pollution—Now and
in the Future," Public Works 94-96, June 1964.
52. U. S. Department of Health, Education, and Welfare. "Pollution-
Caused Fish Kills in 1964," PHS Pub. No. 847, 1965.
53. U. S. Department of the Interior. "Pollution-Caused Fish Kills
in 1965," WP-12, FWPCA, 1966.
54. Kansas Forestry, Fish and Game Commission, 1967.
-------
169
55. Miner, J. R. , Lipper, R. I., Fina, L R. and Funk, J. W.
"Cattle Feedlot Runoff—Its Nature and Variation," JWPCF
3S_, 1582-1591, 1966.
56. Loehr, R. C. "Annual Progress Report--FWPCA Demonstration
Grant WPD-123-01-66--Cattle Feedlot Waste Water Treatment,"
July 1967.
*57. Smith, S. M. and Miner, J. R. "Stream Pollution from Feedlot
Runoff," 18-25, Trans. 14th Ann. Conf. o_n San. Engr. , Univ.
of Kans., 1964.
58. Keller, W. D. and Smith, G. E. "Ground Water Contaminations
by Dissolved Nitrate," Paper presented at the 164th Meeting
of the Geological Soc. of America.
59. Hanway, J. J. , Herrick, J. B., Willrlch, T. L. , Bennett, P. C.,
and McCall, J. T. "The Nitrate Problem," Special Rept. No. 34,
Iowa State University, Coop. Ext. Serv., Agric. and Home
Economics, Aug. 1963.
*60. Willrich, T. L. "Management of Agricultural Resources to
Minimize Pollution of Natural Waters," Nat. Symp. on Quality
Standards for Natural Waters, Univ. of Mich., 303-314, 1966.
61. Loehr, R. C. "Effluent Quality from Anaerobic Lagoons Treating
Feedlot Waste," JWPCF 39, 384-391, 1967.
*62. Decker, W. M. and Steele, J. H. "Health Aspects and Vector
Control Associated With Animal Wastes," Proc. Nat. Symp. on
Animal Waste Management, 18-20, ASAE Pub. No. SP-0366, 1966.
63. Willrich, T. L. "Animal Wastes and Water Quality," Dept.
of Agric. Eng., Iowa State Univ., April 1967.
64. Oglesby, W. C. "Bovine Salmonellosis in a Feedlot Operation,"
Vet. Med/Small Animal CUn. 59, 172-174, 1964.
65. Gibson, E. A. "Salmonellosis in Cattle," Agriculture 73,
213-216, 1966.
66. Gibson, E- A. "Disposal of Farm Effluent—Animal Health"
Agriculture 74. 183-192, 1967.
67. Hibbs, C. M. and Foltz, V. D. "Bovine Salmonellosis Associated
with Contaminated Creek Water and Human Infection," Vet. Med/Small
Animal Clln. 59, 1153-1155, 1964.
-------
170
68. Geldrich, E. E., Bordner, R. H., Huff, C. B., Clark, H. F.,
and Kabler, P. W. "Type Distribution of Coliform Bacteria
in the Feces of Warm Blooded Animals," JWPCF 34, 295-301,
1962.
69. Geldrich, E. E. "Origins of Microbial Pollution in Streams,"
presented at a Symposium on "Transmission of Viruses by the
Water Route," Dec. 1965, Cincinnati, Ohio.
70. Hart, S. A., Black, R. J., Smith, A. C. "Dairy Manure
Sanitation Study," Calif. Vector Views 7, 7, 12, July,
Dec. 1960.
*71. Painter, H. A. "Treatment of Wastewaters from Farm Premises,"
Water and San. Engr. and Waste Treatment Journal, March/April
1957.
72. Black, A. P. and Christman, R. F. "Characteristics of Colored
Surface Waters," JAWWA 55, 753-770, 1963.
73. United States Air Force School of Aerospace Medicine. "Hestianic
Acid—A Biologically Resistant Pigment from Aerobic Waste Digesters."
Tech. Doc. Rept. No. SAM-TDR-63-57, October 1963.
74. Hart, S. A. "Sanitary Engineering in Agriculture," Trans. 14th
Ann. Conf. on San. Engr., 5-10, Bull, of Engr. and Architecture
No. 52, Univ. of Kansas, Lawrence, 1964.
75. Taiganides, E. P. "Digestion of Farm Poultry Wastes," Nat. Symp.
on Poultry Ind. Waste Management, Univ. of Nebraska, May 1963.
76. Gates, C. D. "Treatment of Long Island Duck Farm Wastes," Research
Rept. No. 4, New York State Water Pollution Control Board, 1959.
77. Johnson, C. A. "Disposal of Dairy Manure," Trans. ASAE 8, 110-112,
1965.
78. Johnson, C. A. "Liquid Handling of Poultry Manure," Trans. ASAE
JJ, 110-112, 1965.
79. Ludington, D. C. "Properties of Chicken Manure Affecting Their
Disposal," Presented at the 1966 AAAS Conf. Sect. 0., Dec. 1966.
80. Berry, E. C. "Requirements for Microbial Reduction of Farm Animal
Waste," Proc. Nat. Symp. Animal Waste Management, ASAE Pub. No.
SP-0366, 56-58, 1966.
-------
171
81. Al-Timimi, A. A., Owings, W. J. , and Adams, J. L. "Effect of
Air and/or Heat on the Rate of Accumulation of Solids in
Indoor Manure Digestion Tanks," Poultry Science 43, 1051-56,
1964.
82. Converse, J. C., Pratt, G. L., Wetz, R. L., Butler, R. G. , and
Parsons, J. L. "The Effect of Low Volume and High Volume
Aeration in a Hog Lagoon." Presented at the ASAE Winter
Meeting, Chicago, 1966.
83. Linn, A. "Whipping the Manure Problem," Farm Quarterly
56-59, Winter 1966-67.
84. Forsyth, R. J. "The Collection of Manure from Housed Livestock,"
Jour, and Proc. of_ the Inst. £f Agric. Engineers 21, 124-134, 1965.
85. Morris, W. H. M. "The Treatment of Manure in Oxidation Ditches,"
paper submitted to Purdue Agricultural Experiment Station for
publication, 1967.
86. Parker, C. D. , Jones, H. L., and Taylor, W. S. "Purification
of Sewage in Lagoons," S & IW. 22, 760-775, 1950.
87. Parker, C. D., Jones, H. L., and Greene, N. C. "Performance
of Large Sewage Lagoons at Melbourne, Austrailia," S & IW,
31, 133-152, 1959.
• .
88. Golueke, G. G. , Oswald, W. J., and Gee, H. K. "Processing
High-Rate Pond Loading by Phase Isolation—Final Report,"
San. Eng. Research Lab., Univ. of Calif., Berkeley, 1962.
89. Etzel, J. E. "Industry's Idea Clinic," JWPCF 36, 943-944, 1964.
90. Parker, C. D. "Sewage Treatment by Lagoons," Jour. San. Engr.
Div. ASCE 84 SA3, 1958.
91. Sollo, F. W. "Pond Treatment of Meat Packing Plant Wastes,"
Proc. 15th Purdue Ind. Wastes Conf., 386-391, 1961.
92. Steffen, A. J. and Bedker, M. "Operation of Full-Scale
Anaerobic Contact Treatment Plant for Meat Packing Waste,"
Proc. 16th Purdue Ind. Wastes Conf., 423-437, 1962.
93. Agnew, R. W. and Loehr, R. C. "Cattle Manure Treatment
Techniques," Proc. Nat. Symp. Animal Waste Management,
ASAE Pub. No. SP-0366, 81-85, 1966.
-------
172
94. Al-Timimi, A. A., Owings, W. J., and Adams, J. L. "Effects
of Volume and Surface Area on the Rate of Accumulation of
Solids in Indoor Manure Digestion Tanks," Poultry Science
44, 112-115, 1965.
95. Adams, J. L. and Owings, W. J. "Indoor Lagoons for Poultry
Manure Disposal," Poultry Science 41, 16-21, 1962.
96. Kountz, R. R. and Wooding, N. H. "Lagoons for the Disposal
of Farm Wastes," presented at the Animal Waste Meeting,
North Atlantic Section, ASAE, Orono, Maine, 1963.
97. Anon. "Problems with Indoor Lagoons," Poultry Digest 25,
468, 1966.
98. Anon. "This Liquid Manure System Works," Hoard's Dairyman
112, 16-18, Jan. 10, 1967.
99. Smith, R. J. and Hazen, T. E. "The Amelioration of Odor and
Social Behavior in, Together with the Collections from, A
Hog House with Recycled Wastes," Presented at the 60th Annual
Meeting, ASAE, June 1967.
100. Hart, S. A. "Thin Spreading of Slurried Manures," Agric.
Engr.
101. Reed, C. H. "Furrow Manure Disposal," Poultry Digest 24,
278, 1965.
102. Anon. "How We Handle Liquid Manure." Hoard's Dairyman 109,
1254, Nov. 25, 1964.
103. U. S. Department of Agriculture. Soil Yearbook of Agriculture,
229-237, 1957.
104. Eby, H. J. "Two Billion Tons of—What?" Compost Science 7,
7-10, 1966.
105. Riley, C. T. "Poultry Manure Disposal—Is There a Problem?"
Agriculture 73. 110-112, 1966.
106. Rundle, W. T. A. "Effluent Disposal—Still a Major Problem,"
Jour, and Proc. of_ the Inst. £f_ Agric. Engineers 21, 134-139,
1965.
107. Gatehouse, H. C. E. "Disposal of Farm Effluent," Agriculture
74, 89-44, 1967.
-------
173
108. Ludington, D. C. "Dehydration and Incineration of Poultry
Manure," Nat. Symp. on Poultry Industry Waste Management,
Lincoln, Nebraska, 1963.
109. Wiley, J S. "A Report on Three Manure Composting Plants,"
Compost Science 5^ 15-16, Summer 1964.
110. Livshutz, A. "Aerobic Digestion (Composting) of Poultry
Manure," World's Poultry Sci. Jour. 20, 212-215, 1964.
111. Hammond, W. C., Day, D. L. , and Hansen, E. L. "Treatment
of Liquid Hog Manure to Suppress Odors," presented at the
ASAE Winter Meeting, Chicago, 1966.
*112. Anon. "Some Further Observations of Waste Waters from Farms,"
Notes on Water Pollution No. 24, Dept. of Science and Ind. Research,
HMSO, March 1964.
*113. Wheatland, A. B. and Borne, B. J. "Treatment of Farm Effluents,"
Chem. and Ind., 357-362, 1964.
114. Bridgham, D. 0. and Clayton, J. T. "Trickling Filters as
a Dairy Manure Stabilization Component," Proc. Nat. Symp.
Animal Waste Management, ASAE Pub. No. SP-0366, 66-68, 1966.
115. Howes, J. R. "On-Site Composting of Poultry Manure,"
Proc. Nat. Symp. Animal Waste Management, ADAE Pub.
No. SP-0366, 68-70, 1966.
116. Diebel, R. H. and Sobel, A. T. "Chlorination of Duck Wastes,"
Unpublished Report, Cornell University, Agric. Engr. Dept.,
1966.
117. Pryor, W. J. and Connor, J. K. "A Note on the Utilization
by Chickens of Energy from Faeces," Poultry Science 43,
833-834, 1964.
118. Bull, L. S. and Reid, J. T. "Observations on the Nutritive
Value of Chicken Manure for Cattle," Unpublished Report,
Cornell University, Dept. of Animal Husbandry, 1965.
119. Fontenot, J. P., Bhattacharya, A. N., Drake, C. L., and
McClure, W. H. "Value of Broiler Litter as Feed for
Ruminants," Proc. Nat. Symp. Animal Waste Management,
ASAE Pub. No. SP-0366, 105-108, 1966.
-------
174
120. Anthony, W. B. "Utilization of Animal Waste as Feed for
Ruminants," Proc. Nat. Symp. Animal Wastes Management,
ASAE Pub. No. SP-0366, 110-112, 1966.
121. Durham, R. M., Thomas, G. W. , Albin, R. L., Howe, L. G.,
Curl, S. E., and Box, T. W. "Corophagy and Use of Animal
Waste in Livestock Feeds," Proc. Nat. Symp. Animal Wastes
Management. ASAE Pub. No. SP-0366, 112-114, 1966.
*122. Allred, E. R. "A Review of Rural Waste Disposal Practices
in Northern Europe," Rept. No. 205, Dept. of Agric. Engr.,
Univ. of Minnesota, Jan. 1966.
123. Stubblefield, T. M. "Problems of Cattle Feeding in Arizona
as Related to Animal Waste Management," Proc. Nat. Symp.
Animal Wastes Management. ASAE Pub. No. SP-0366, 120-122,
1966.
*124. Taiganides, E. P. "Disposal of Animal Wastes," Proc. 19th
Ind. Wastes Conf., Purdue Univ., 281-290, 1964.
125. Anon. "Missouri Cattle Feeding Manual," Manual No. 65, Univ.
of Missouri Agric. Expt. Station, Columbia, Mo., July 1965.
126. Williams, W. F. and McDowell, J. I. "Costs and Efficiency
in Commercial Dry-Lot Cattle Feeding," Proc. Series P509,
Oklahoma State Univ. Expt. Station, June 1965.
127. Paul, A. B. and Wesson, W. T. "Pricing Feedlot Services
Through Cattle Futures," Agric. Econ. Research 19, 33-45,
1967.
128. Van Arsdall, R. N. "Resources Requirements, Investments,
Costs and Expected Returns from Selected Beef Feeding
and Beef Raising Enterprises," Rept. No. AE-4075, Illinois
Agricultural Experiment Station, Univ. of 111., 1965.
129. Kesler, R. P. "Economic Evaluation of Liquid Manure
Disposal from Confinement Finishing of Hogs," Proc.
Nat. Symp. Animal Waste Management, ASAE Pub. No.
SP-0366, 133-135, 1966.
130. Steinfeldt, W. M. and Garrett, J. T. "Oxidation of
Organic Wastes in Stabilization Ponds," Public Works,
196-199, Sept. 1959.
-------
175
131. Forges, R. "Industrial Waste Stabilization Ponds in the United
States," JWPCF 35, 456-468, 1963.
132. Lynam, B., McDonnell, G., and Krup, M. "Start-Up and Operation
of Two New High-Rate Digestion Systems," JWPGF 39, 518-535, 1967.
133. American Public Works Association, Municipal Refuse Disposal,
2nd Ed., Public Administration Service, 1966.
134. Griffin, G E. "Sewage Sludge Disposal in Westchester County,"
Jour. San. Engr. Div,, ASCE 85, SA5, 1-8, 1959.
135. Progress Report of the Committee on Sanitary Engineering Research,
"Sludge Treatment and Disposal by the Zimmerman Process," Jour.
San. Engr. Div.. ASGE 85, SA4, 13-23, 1959.
136. Teletzke, G. H. "Wet Air Oxidation of Sewage Sludge," Trans.
16th San. Engr. Conf., Univ. of Kansas, 25-30, 1966.
137. Dworsky, L. B. "Analysis of Federal Water Pollution Control
Legislation 1948-1966," JAWWA 59. 651-668, 1967.
138. Wisdom, A. S. The Law £n the Pollution of_ Water. Shaw and
Sons, Ltd., London, 2nd Ed., 1966.
139. Anon. Kansas City Star and Times, August 18, 1967.
140. Bacon, V., Dinner Speaker, National Conference on Sanitary
and Environmental Health Engineering Education, Evanston,
Illinois, August 29, 1967.
141. Whitehair, N. V. "Fall and Winter Outlook--1967-1968--
August," Extension Economics, Kansas State University,
1967.
------- |