Blackburn Wastewater Treatment Plant Upgrade Study

Section 3.0 -Audit of Existing Facilities
secondary digester. Sodium percarbonate is added to the digesters for
hydrogen sulphide and odour control.
The digested sludge is dewatered on belt filter presses manufactured by
Envirex. Each press has a 2 rn wide gravity section, and a 1 m wide pressure
section. The presses are operated for 7 h/4 4 to 5 &week. Percol757 polymer
and a potato starch based product (Raifix) are used as coagulants. The presses
produce a sludge cake with a dry weight solids content of approximately 22
percent.
3.3 Operations Staff
The Blackburn and Lansdowne Road WWTPs are operated by a full time sta!T
of eight persons consisting of one Class IV chief operator, a laboratory
technician, 2 Class I1 operators, and 4 Class I operators. The operating staff
are all based at the Lansdowne Road facility, where most of their duties are
carried out. One operator spends 1 hld, 7 dweek to do a daily inspection at the
Blackburn WWTP, and 4 hours once monthly to do the effluent composite
sampling and preventive maintenance. Other City tradespeople (millwright,
electrician, instrument technician) are called to the plants on an "as required"
basis.
3.4 Conclusion
The existing Lansdowne Road WWTP was designed for an ADWF of 44.5
Mud and a PWWF of 115 Mud. The plant is currently treating
approximately 30 MU& or 67 percent of its design flow and load, and does not
appear to have any unit processes in either the liquid or sludge treatment
streams that are close to capacity and may serve as a "bottleneck" if flows to
the plant were increased by a modest amount. The current dry weather flows
and loads h m the Blackbum catchment represent less than 2 percent of the
design capacity of the Lansdowne Road WWTP. The current wet weather
flows (i.e. prior to implementation of the VI mitigation measures) represent
less than 5 percent of the hydraulic capacity of the Lansdowne Road WWTP.
Even with the expected increase in flows and loads from Blackbum sewage
collection area as a result of increasing the serviced population to 5,000, these
flows and loads represent less than 4 percent of the design capacity of the
Lansdowne Road WWTP.