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Public Hearing Notice Regarding Wastewater Project

PUBLIC HEARING NOTICE – WWTP IMPROVEMENTS SRF LOAN APPLICATION AND ENVIRONMENTAL INFORMATION DOCUMENT

 

 

The City of Forest City will be holding a Public Hearing to review an application for a State Revolving Fund (SRF) loan and to make available to the public the contents of an environmental information document and the City’s project plan.  These documents include design and environmental information related to the proposed improvements to the City’s wastewater treatment plant.

 

The proposed project eliminates the existing rotating biological contactors (RBC) and converts the treatment plant to a suspended growth process using activated sludge to facilitate biological phosphorus removal and denitrification. The suspended growth process will be an Enhanced Biological Nutrient Removal (EBNR) system utilizing the A2O process configuration. Existing RBC equipment and structures will be demolished. Two (2) oxidation ditches will be installed with mechanical mixing/aeration and built-in anaerobic and anoxic zones to provide biochemical oxygen demand (BOD), ammonia nitrogen, and phosphorus removal. 

 

Conversion to an activated sludge system necessitates additional final clarifier capacity due to an increased overflow rate to these structures. Primary clarification is not required ahead of the activated sludge process, and these structures will be demolished or repurposed. A chemical feed system (aluminum sulfate or ferric chloride) will be installed to supplement the EBNR system by removing phosphorus via chemical precipitation within the final clarifiers. The two (2) existing anaerobic digesters will be converted to an aerobic digestion system, including aeration blowers and piping. To handle the increase in sludge production from chemical phosphorus removal, a third aerobic digester will be constructed. The existing sludge drying beds will be demolished and a biosolids storage tank will be constructed in their place for better storage capacity at the plant. Equipment and channel floors of the existing UV structure will be elevated. Work associated with the UV system modifications will occur within the footprint of the existing structure. Approximate dimensions of excavation for structures are as follows:

 

Oxidation Ditch: 90’ W x 150’ L x 10’ D 

Biosolids Storage Tank: 87’ Dia. x 24’ D

Additional Digester: 30’ Dia. X 29’ D

RAS/WAS Pump and Chemical Feed and Storage Building: 32’ W x 26’ L x 14’ D

New Final Clarifier: 42’ Dia. x 12’ D

Final Clarifier Splitter Structure: 27’ L x 11’ W x 9’ D

 

The facility is also due for several age-related equipment replacements over the next 20 years, including various pumps, piping, and electrical/controls.

 

The purpose of this Public Hearing is to inform area residents of the Forest City community of this proposed action, discuss the actual cost and user fees associated with this project, and to address citizen’s concerns, if any, with the plan.

 

The Public Hearing location and time are as follows:

 

            March 4, 2024, 7:00 p.m.

            City Hall

            305 N. Clark Street

            Forest City, Iowa 50436

 

All interested persons are encouraged to attend this hearing.  Written comments on this proposal may also be submitted prior to the hearing.  Questions regarding this hearing or the availability of documentation may be directed to the City Administrator at 641-585-3574. Additionally, public comments can be sent to SRF-PC@dnr.iowa.gov.