Blackburn Wastewater Treatment Plant Upgrade Study

Section 4.0 - Blackbum Treatment Options
4.6 OPTION 6 - UPGRADE AND EXPAND BLACKBURN WWTP TO
TREAT PROJECTED FLOWS AND LOADS
4.6.1 Outline
In this option the existing sewage lagoons would be upgraded and expanded to
handle projected flows and loads from the Blackburn sewage collection area,
for an ultimate population of 5,000 persons, and to meet required effluent
standards. The existing treatment system consists of two aerated lagoons,
sized to accommodate a contributing population of 2,500. Expanding the
lagoon system to handle the ultimate population of 5,000 would involve
doubling its present size. The expanded lagoon system will address
conventional treatment requirements for BODs and TSS removal. However,
the lagoon system must also ahress removal of ammonia toxicity. Because of
the winter and early spring weather conditions experienced in the Prince
George area, it is practically impossible to achieve ammonia removal by
nitrification in an aerated lagoon system. The issue of ammonia toxicity
removal would have to be addressed by considering the addition of a tertiary
rotating biological contactor (RBC) process to provide nitrification of the
lagoon emuent. A schematic representation of this option is presented in
Figure 4.6. An VI reduction program is to be implemented to reduce the
volume of wastewater being treated in the lagoons during wet weather and
snowmelt conditions. The existing Mackus Road pumpstation would be
upgraded.
Key activities or capital works associated with this option are as follows:
Implement I/I reduction program.
Rehabilitate existing lagoons.
Double lagoon capacity.
Upgrade Mackus Road pumpstation to handle projected increased flows.
Address ammonia toxicity issue by considering the use of a tertiary
nitrifying RBC.
Key technical issues associated with this option are as follows:
Extent to which the VI reduction program will reduce peak wet weather
flows must be evaluated.