United States
Environmental Protection
Industrial Environmental
Research Laboratory
Cincinnati OH 45268
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-

  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

  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

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

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
  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
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
   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
   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

United States
Environmental Protection
Official Business
Penalty for Private Use $300
             Center for Environmental Research
             Cincinnati OH 45268
            S8S  |0NyIR«UTbCTIO,  AGENCY