Sludge Pumping
The sludge and
skimmings from the primary and final clarifiers flow to a pit at the east side
of the operations building. Pumps in the lower level of the building move the
sludge to the aerated sludge lagoon. Alternatively, the sludge can be pumped
directly to a sludge tank wagon for disposal on agricultural land if, for some
reason, the sludge cannot be pumped to the lagoon system.
Sludge Lagoon
System
The waste
sludge is pumped to what was formerly the lagoon system. It has been modified
to accomplish sludge treatment, however, instead of wastewater treatment. The
waste sludge goes first into the aerated lagoon, which has both diffused
aeration plus continuous recirculation pumping. The solids are, thus, kept in
suspension and are provided with oxygen. In the aerobic environment, the solids
decompose, or stabilize, without causing odor problems.
After
receiving treatment in the aerated lagoon, waste sludge flows into the large
lagoon cell for storage. There is no discharge from the large cell, so excess
water is removed only by evaporation.