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Oxidation Ditch and Final Clarifier
Greater Bayfield WWTP, WI
The Bayfield WWTP and the Pikes Bay
Sanitary District (PBSD) aerated lagoon WWTP were both
designed by our firm in the early 1970s. The City of
Bayfield’s effluent is well below permit limits.
However, flows and loadings to both treatment plants
continue to increase because of increasing tourism in
this beautiful area on the shores of Lake Superior.
We originally explored regional wastewater treatment
facilities with the City and Town of Bayfield, Pikes Bay
Sanitary District, and the Red Cliff Band of Lake
Superior Chippewa. The study evaluated alternative
sites and methods for treatment, including zero
discharge to Lake Superior. We addressed conveyance
requirements, addressed siting and permitting issues,
projected future wastewater flows and loadings,
evaluated treatment alternatives, and performed a
cost-benefit analysis. We
were able to obtain unique grant
funding for the study
through the Great Lakes Protection Fund administered by
the Wisconsin DNR. We also assisted the communities in
identifying potential funding sources for potential
future wastewater conveyance and treatment
projects.
Sludge Reed Beds
The plant
will consist of fine screening, extended aeration
activated sludge treatment with biological nutrient
removal (with backup chemical phosphorus removal), final
clarification, innovative cloth disk filtration, UV
disinfection, and discharge to a dry run tributary to
Lake Superior. This combination of technologies is
expected to achieve a much higher quality effluent than
would be achieved if the communities had pursued
independent projects. The plant will be readily
expandable to accommodate future connections and
growth.
Please visit the City of
Bayfield's website
and view the narrated slideshow
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Fond du Lac Water Pollution Control Facility
Facilities Planning – Fond du Lac, WI
We
performed facilities planning for an existing 11.1-mgd
average daily flow, nominal 35-mgd peak hourly flow
wastewater treatment facility. The Fond du Lac Water
Pollution Control Plant (WPCP) currently includes
preliminary treatment (comminution and grit removal),
primary sedimentation, oxygen-activated sludge (UNOX
System), final clarification, and disinfection (sodium
hypochlorite and sodium bisulfite) with a discharge to
Lake Winnebago. The solids processing at the current
facility includes co-thickening of the waste activated
sludge in the primary sedimentation tanks, Zimpro
wet-air oxidation of the biosolids followed by vacuum
filtration. The biosolids are currently landfilled.
The
Facilities Plan recommended an increase in the nominal
peak hourly flow to 50 mgd. The recommended plan
includes a new influent pumping station, preliminary
treatment (fine screening and grit removal), primary
sedimentation, single sludge activated sludge designed
to meet ammonia effluent limits, UV disinfection,
biosolids stabilization using pasteurization followed by
thermophilic phased anaerobic digestion, and biosolids
dewatering using centrifuges.
The modified Fond du Lac WPCP will include facilities to
handle peak hourly flows by providing preliminary
treatment, grit removal, primary sedimentation, storage,
and UV disinfection for 16 mgd of the total 50 mgd peak
hourly flow. The excess flow effluent will be blended
with the 34 mgd receiving biological treatment prior to
UV disinfection. The project will also include
providing emergency power and new administration and
maintenance facilities.
The Facilities Plan was approved by the City Council of
Fond du Lac in March 2004. Strand is currently
designing the modifications to the Fond du Lac WPCP with
an anticipated completion for this project is October
2008.
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