United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Cincinnati OH 45268
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oW^
Research and Development
EPA-600/S2-84-043 July 1984
Project Summary
Waste Management Control
Handbook for Dairy Food Plants
W. J. Harper, Roy E. Carawan, and M. F. Parkin
In dairy food plant operations,
resource management control can
reduce losses in product, water, energy,
labor, packaging, and sewer
surcharges. An efficient program of
waste control can increase the profit
margin and help to improve the
environment in which we live. These
economic and environmental factors
justify the full-time assignment of one
or more persons reporting directly to
the plant manager.
The handbook described herein,
presents a detailed plan for implemen-
tation of a source management program
which includes maintenance and educa-
tion information for labor and manage-
ment.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory. Cincinnati. OH.
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The reduction in loss of product, water,
and energy in dairy food plant operations
is a goal toward which all dairy plants
must strive to improve products, minimize
impact on the environment and to meet
Federal, State, and local regulations The
handbook described herein is directed
primarily toward individuals who have
direct responsibility for the development
and operation of a waste control program
in a dairy food plant.
Dairy plant losses can be categorized
as (a) unavoidable, and (b) preventable.
Unavoidable losses are related to plant
and process design and are primarily
associated with cleaning operations. Pre-
ventable losses, usually over 50% of all
losses, are those that can be eliminated
by good operational practices. A waste
control program aims at eliminating pre-
ventable losses and applying engineering
improvements to equipment and process
design to minimize the level of
unavoidable losses.
The information presented in the
handbook was developed primarily from
experience gained in working with waste
control programs in milk, ice cream, and
cottage cheese plants. Although many of
the illustrations and examples cited come
primarily from those products, the
principles expressed apply equally in
plants manufacturing any dairy product
The handbook can also be used for
development of waste control programs
in other food industry plants.
Experience shows that the approaches
outlined in the handbook can reduce
product losses, organic waste loads,
water loss and energy wastage by at least
50% in an average plant, when fully
supported at all levels of management
and operational personnel. The success
of the program depends upon the
motivation of people and continued
attention to a well-organized program. All
too often a control program is instituted,
works very well in the beginning then,
because of lack of continued attention,
the waste situation rapidly deteriorates.
Waste control is an important aspect of
resource management control and an
essential part of dairy food plant
operations. Waste control (quantity
control) should be recognized as equal in
significance to quality control. Where
plant size warrants, the quantity control
task warrants the full-time assignment of
at least one person to the waste control
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program. Only when this area is given full
time attention can long-term benefits be
achieved. In most situations, the time
spent by one or more individuals will be
repaid to the company over a period of a
year.
Environmental Effects of
Dairy Wastes
The major pollutant and waste dis-
charged from dairy plants is organic
material. This is milk diluted with water
discharged as wastewater. When
dumped untreated into a stream or river,
organic material is decomposed by
microorganisms in the river. When
breaking down the organic pollution, the
microorganisms consume oxygen in the
water. That action can degrade the water
by depleting its oxygen content. Oxygen
depletion, in turn, can have a catastrophic
impact on life in the water body for fish or
other aquatic animals and on plants
which must have dissolved oxygen to
survive. When all oxygen in a water body
is used up, as frequently happens, the
decay of organic matter continues
without the oxygen. As a result, noxious
gases such as hydrogen sulfide and
methane are produced and result in an
odor much like that of a septic tank.
The measurement of pollutants that
consume oxygen in water is called
biochemical oxygen demand, or BOD
Water with high BOD contains a large
amount of decomposed or organic matter.
Another pollutant in dairy plant
discharges is suspended solid waste,
such as coagulated milk, particles of
cheese curd, and in an ice cream plant,
pieces of fruit and nuts. This type of
pollutant is called total suspended solids,
or TSS. These solids discolor and cloud
the water They impair photosynthesis in
the aquatic plants. They can settle on the
bottom and become sludge beds and
further deplete the waters' oxygen
content As the sludge decomposes, it
gives off gases that are toxic to aquatic
life.
Raw wastes from the dairy plant
contain excessive amounts of organic
materials and suspended solids. These
wastes must be treated before they can
be discharged into a river or stream The
major dairy industry water pollutants,
organic materials and suspended solids,
can be treated successfully either by a
municipal treatment facility or by an on-
site plant operated by the dairy. Other
identified pollutants in dairy plant wastes
that may be of concern include
phosphorus, nitrogen, chlorides, and
heat. Another consideration is the pH of
the wastes. In some situations, whey
creates a problem for municipal
treatment plants. This usually occurs
where the whey discharge is a significant
portion of the load to the municipal plant.
The wastewater characteristics for
dairy plants are extremely variable. The
data of many authors who have studied
dairy operations indicate that wastewater
parameters may have a range as wide as
shown below:
BOD5 - 500 to 5,000 mg/L
SS - 400 to 3,500 mg/L
Fat - 200 to 3,000 mg/L
Flow - 0.5 to 20 pounds per
pound of product
Economic Considerations
Water and sewer charges for larger
dairy processing plants can exceed
$50,000 per month. Water and sewer
charges are estimated at less than
$2,000 a month for the average dairy
plant Surcharges can approach $5,000
to $10,000 per month for the same
average dairy plant. Waste treatment
plants for a large dairy processing plant
might cost $1.5 to $2.5 million to meet
rigid effluent standards. A strong
economic incentive to build such waste
treatment plants is the cost of water,
sewers, and surcharges — estimated at
more than 1 /3 of a cent per gallon for a
well-operated dairy plant. Plants without
adequate waste control programs might
pay bills for water, sewer and surcharges
which exceed 1 cent per gallon of
processed products. When the average
dairy plant makes only 2.6% profit basei
on sales, and when more than 2/3 of <
cent per gallon of profit can be gaine<
from waste control, then control o
wastes becomes economically attractivi
to dairy plants.
The increase in cost of energy als<
relates to waste control programs. Muc
of the product that is lost during pro
cessing has been pumped, chilled, heatec
and homogenized. Because each of thesi
cleaning processes require great quan
titles of warm or hot water, the control o
waste also controls energy losses.
The handbook fully discusses all of the
economic factors of waste treatmen
processes.
Legal Considerations
States have the authority to enforci
Federal Standards. Most state;
previously required permits for direc
discharges of wastewater. Then PL 92
500 set up a new system of permits at tht
Federal level 1 — the NPDES of Nationa
Pollutant Discharge Elimination Systerr
Permits which were developed anc
promulgated by the United States
Environmental Protection Agency (EPA)
Now, most states write and enforce the
NPDES permits. However, EPA reserve;
the right to check on the actions of the
state. While the law requires industries tc
follow municipal discharge standards se
for 1977 and 1983, the law also allows £
state or community to impose strictei
requirements if it wishes The nationa
standards are thus minimurr
requirements that all industries must
meet.
I/I/. J. Harper is with Ohio State University, Columbus, OH 43210; Roy E. Carawan
is with North Carolina State University, Raleigh, NC 27607; andM. F. Parkin is
with the New Zealand Dairy Research Institute, Palmerston North, New
Zealand.
Fred W. Craig is the EPA Project Officer (see below).
The complete report, entitled "Waste Management Control Handbook for Dairy
Food Plants," (Order No. PB 84-152 826; Cost: $20,50, subject to change) will
be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U S GOVERNMENT PRINTING OFFICE, 1984 — 759-015/7749
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