PC PACKET 05.09.2024 - Laserfiche WebLink

Home

Liberty Classical Academy: Phase 1—Lower School Addition 11/30/23—Revised 05/06/24 Page 4 Fire protection: The intent for phase one fire protection will be to use the existing underground tank and extend the existing fire suppression system.The new addition will be classified as the same hazard as the existing school,so there should not be any increase to the demand.Since this project is design build for Mechanical Electrical and Plumbing,we will know more information about the fire protection systems once we are complete with construction documents. Well: Please see attached memo from Short Elliott Hendrickson. Septic: The project is outside the City of Hugo's Municipal Service Area and will require an On-site Wastewater Treatment System (OSWTS). Under Minnesota Pollution Control Agency(MPCA) regulations,the OSWTS will require a permit from the MPCA for the entire master plan design flow,since the estimated wastewater flow will be more than 10,000 gallons per day (GPD). The OSWTS will be phased for the entire build out,and for phase 1 will be sized for the flow rate of the existing school and building expansion for phase 1. We have submitted a complete permit application to the MPCA and are having ongoing discussions with the MPCA staff in working towards obtaining a permit. Based on current water usage rates at the existing school,the current water usage is averaging 12-14 GPD per student. MPCA Chapter 7080 requires a design flow rate of 18 GPD/student without a gym, but allows for flexibility in reducing flows based on the actual water usage. For this reason,we are proceeding with a design flow rate of 18 GPD/student and faculty member. A summary of the anticipated phase 1 and Phase 2 design follows: Number of Students Number of Faculty Total Flow(gpd) Lower School 1 336 35 6,678 A gravity collection system will be installed that collects the wastewater from each of the school buildings via gravity to a central lift station. The lift station is being sized to handle the flow for phase 1 and will be able to be upgraded with minor modifications to handle the ultimate flow as the campus grows. From the lift station,the wastewater will be pumped through a forcemain to the septic tanks located on the east side of the property. The septic tanks will provide the first step in the treatment process with removing the large solids,fats,oils, and greases. For the flows of phase 1,we anticipate having two(2) 10,000-gallon septic tanks for a total of 20,000 gallons of septic tank capacity. From the septic tanks,the effluent will flow by gravity to a 20,000-gallon equalization tank,this tank will be used as the primary treatment system and absorb any peak flows to maintain a constant flow through the biological treatment process. For the equalization basin,the effluent will enter a 12,000-gallon Pre-Denitrification tank,this tank will allow the addition of a carbon source or effluent for the treatment process to be recruited to aid in the removal of nitrogen in the effluent. Once the effluent has passed through the Pre-Denitrification Tank, it will enter two(2) 3,000 MBBR treatment tanks. These tanks will introduce air into the effluent to increase biological activity to remove the nutrients in the wastewater.Then the effluent will pass through a 5,000-gallon post Denitrification tank and into a 10,000-gallon clarifier,to remove any remaining solids.