The City’s preference is to replace the existing Waukesha Engine with 2 CAT engines.
What is the preferred CAT engine model?
Answer: We expect the consultant to meet with CAT representatives to go over suitable
CAT gas generators based on the design parameters determined by the consultant. Once
a suitable CAT model is determined it will be discussed with the City for final approval.
What is the future expansion plan for gas production and electrical consumption?
Answer: At this time we do not know how much to expect for an increase in digester gas
production. There could be slightly higher loadings to the digester with upgrades to the
primary sedimentation tanks (currently in design phase, upgrades are expected to be
complete in about 2-3 years) which may result in slightly higher gas production. As the
City population continues to grow, more solids will feed the digester resulting in an
increased gas production. However, the rate of growth is very slow. In summary we do
not expect much greater gas production than the system currently produces for the near
future unless a supplemental food source (more septic loads, food waste...) is brought in.
Please provide information on the existing plant control system (Delta V, etc.).
Answer. The gas generator will be controlled by a control panel mounted on or adjacent
to it. This was the arrangement when the Waukesha generator was operational. SCADA
is used to monitor the cogen system: check gas production, flow rates, check generator
production (Kw), check coolant temperature, review trending...
What are the evaluation parameters for the gas cleansing room, exhaust gas flare, gas
hold tank feed system?
Answer: The crux of this project is to replace the existing Waukesha generator with 2
new CAT generators each sized to meet the gas generation production rate, and the
replacement of associated components in need of replacement (heat exchangers, exhaust
system, controls...)._ However, we expect the consultant to conduct an overall evaluate
the other components of the cogen system. Equipment in the gas cleansing room, boiler
room... Should be evaluated to be certain it is sized correctly and also an estimate of the
useful remaining life. Any recommendations for changes should be noted in the
preliminary design report. If something is in need of immediate replacement it may be
added to the project depending on costs.
What level of assistance should the bidder provide during the bid phase?
Answer: The consultant being hired is just for the design and bidding phases of this
project. The City will send the project out to bid and will seek assistance from the
consultant to answer Contractor questions concerning the plans and specs. We will also
request the consultant to recommend the lowest qualified bidder.
