PERFORMANCE MONITORING PROGRAM—
MOLSON'S BREWERY DEEP SHAFT
TREATMENT SYSTEM
Brian P. Le Clair, Manager
B.P. Le Clair and Associates
Barrie, Ontario
Canada LYM 503
INTRODUCTION
Increased surcharges for the treatment of industrial effluents at municipal treatment works has
resulted in many industries considering pretreatment as the most economical method for controlling
wastewater pollution. In 1971, Molson Ontario Breweries Ltd. in Barrie, Ontario commissioned an
extended aeration wastewater treatment plant to pretreat 4000 m3/d of high strength readily biodegradable brewery wastewater. The effluent was treated in accordance with the City pretreatment
bylaw which requires an effluent discharge from the brewery not exceeding 300 mg/l of TBOD, and
350 mg/l TSS-
Increasing brewery production, rising energy costs, and the urban location of its breweries necessitated investigation of treatment alternatives which were more energy and space efficient. The potential of the Deep Shaft effluent treatment process to fulfill these requirements of reduced energy and
space requirements provided a major incentive to pilot this technology in Barrie. Other advantages
claimed for the process were a lower capital cost and a reduced sludge production when compared
with conventional technology.
In late 1975, Molson's entered into an agreement with Eco Research Ltd., North American licensees of the ICI Deep Shaft Process, to construct a pilot plant. Evaluation programs were conducted
from 1976 to 1978. Throughout this period, the Deep Shaft pilot program was directed primarily at
exploring the merits of the process as a pretreatment system. However, in May of 1978, the pilot plant
program culminated with test results indicating that the process could produce an effluent having an
average TBOD, and TSS less than 50 mg/l.
The pilot results provided sufficient evidence to Environment Canada to allow Molson's to qualify
for a Development and Demonstration Pollution Abatement Technology (DPAT) grant. The objective was to demonstrate the Deep Shaft on a full scale basis as a process capable of producing an effluent of not greater than 50 mg/l TBOD, and 50 mg/l TSS on a 30 day average. Eco Research Ltd. was
contracted to design, construct, and commission a fully operational Deep Shaft effluent treatment
plant. The solids handling and disposal aspects were retained by Molson's, and a separate facility was
constructed in a building attached to the Deep Shaft facility.
The average production day brewery effluent to the Deep Shaft was projected to be 2091 m3/d with
an average TBOD, load of 5000 kg/d and a solids loading of 2500 kg/d calculated on 66 production
days during a previous peak brewing period. The process design called for two, 1.37 m O.D. shafts,
152 m deep with a total aerated volume of approximately 454 m3 and a compressed air requirement of
0.377 m3/s at 680 kPa. For solids separation two flotation tanks were required with a total effective
area of approximately 96.5 m2.
Following completion of the process design, detailed plant design and drilling for shaft placement
began in February 1979. One month later, on March 6, 1979 drilling of the first hole had progressed to
134 m when the drill pipe broke. Fishing operations for the bit were conducted until April 27, 1979. At
that time, an economic decision was made to abandon the hole. The drill rig was relocated May 7,
1979 and by June 3 the new hole was at 152 m. Casing and grouting were completed by June 12, 1979.
The drilling of the second hole began June 22 and was completely Finished including grouting and
pressure testing by July 25, 1979. Effectively, two shafts were placed and grouted in about eleven
weeks.
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