STARTUP PROBLEMS AT A DAIRY WASTE TREATMENT PLANT
Keith A. Radick, Environmental Specialist
Floyd Browne Associates, Limited
Marion, Ohio 43302
The startup and tuning of any new facility, whether production or waste treatment, is
subject to problems. When both a production facility and its accompanying wastewater
treatment plant begin operation at the same time, the number and degree of startup problems seem to be compounded. This was certainly true of the powdered milk processing
facility that provides the basis for this paper.
The following discussion focuses on the effects of the production plant's operating procedures on the effluent quality of the industrial waste treatment (IWTP) and the effects
of inflexible treatment facilities on the operational control and effluent quality of the
IWTP. The final section of the paper presents operation and design changes in the IWTP
that are being made to improve the quality of the wastewater that is discharged by this
powedered milk processing facility.
EXISTING FACILITIES
Production Plant
The production facility is a very modern, computer-controlled milk processing plant.
It is owned by a milk producing cooperative and provides utilization of their surplus milk
by drying into powdered form. The drying plant has the capacity to process 2,000,000
pounds per day of liquid raw milk into powder. Powdered milk is produced in three forms:
nonfat dry milk or skim, whole milk, and buttermilk. In addition, the facility produces
butter and has the capability of producing condensed mUk rather than drying it to powder.
The main source of wastewater generation is the clean-up operations, which consist of
the cleaning of all transport lines and equipment whenever a production run comes to a halt.
Other sources of wastewater generation are related to equipment malfunctions or operation
errors which can cause raw product dumps, overflowing tanks or foaming.
Industrial Waste Treatment Plant
The industrial waste treatment facility discharges directly to a receiving stream and is
therefore subject to the National Pollutant Discharge Elimination System (NPDES). The
NPDES permit issued for this IWTP contains the pollutant limitations listed in Table I.
Additional environmental pressure for good effluent quality comes from local citizens
who are concerned that the wastewater discharge could adversely affect the well-known,
scenic, and prolific trout stream into which the receiving stream flows.
The IWTP was designed to treat average flows of 216,000 gpd; 36,000 gpd of process
wastewater that require full treatment, and 180,000 gpd of condensate wastewater (known
in the industry as COW water) which contains little or no pollutant concentrations and does
not require full treatment.
The IWTP was also designed to achieve 99% removal of BOD5 with influent loadings
of 1665 mg/l (3000 lb/day) and 92% removal of SS, with influent loadings of 270 mg/l
(486 lb/day).
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