Blackburn Wastewater Treatment Plant Upgrade Study

Section 4.0 - Blackbum Treatment Options
HRT (@ ADWF = 1,750 m3/d), d
Lagoon 2N2B (secondary)
Number
Volume, rn3
HRT (@ ADWF = 1,750 m3/d), d
0 Aeration Blowers
Number
Power, hp
Headworks
According to original design data presented on AESL as-built drawing 4102-
01-S-102, the influent works (channels and screens) are adequately sized to
accommodate Stage 2 flows. No major modifications are required in this area.
Aerated Lagoons
The aerated lagoon system will need to be twinned to accommodate the design
ADWF of 1,750 m3/d. Construction work involves the following:
Excavation of two lagoons to the east of the existing two. The dimensions
will be identical to the existing lagoons. The total volume to be excavated
is approximately 23,000 m3. It is assumed some of the excavated material
can be used to extend the berm and no material needs to be imported to
complete construction.
Replacement of both existing 60 hp aeration blowers. Depending on the
mode of operation, the plant presently requires either 1 or both blowers
running; series operation requires 60 hp, and parallel requires 120 hp. Stage
2 requires 150 hp for series and 225 hp for parallel. There is presently
room for three blowers in the existing building. Assuming present
operating practice of no standby capacity during parallel operation is
maintained, three 75 hp (nominal) aeration blowers will be required.
Duplication of the air distribution system (34 "aeration guns" in each
lagoon for a total of 68 new units). If is assumed the air distribution
pipework will be mirrored.
Additional emuent and drain piping will be required to connect the new
lagoons to the chlorine contact chamber. The chlorine contact chamber is
adequate for Stage 2 flows. It is assumed the new emuent pipework will be
of similar configuration to the existing, with approximately 350 m of 300
mm pipe, 2 manholes, and 3 concrete chambers.