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Liberty Classical Academy: Phase 1 – Lower School Addition 11/30/23 – Revised 05/06/24 Page 5 Phase 1 will require a dosing tank and 7 to 8 mounds. The mounds would be fed by a central pump station with valve controls to each mound system. Wetland: There are two (2) wetland areas on the site, one in the Northeast corner of the property surrounding the edge of Goggins Lake and a 0.48-acre wetland on the east side of the existing farmstead. The wetland in the northeast corner of the site will be preserved and a 100 foot buffer has been provided to protect the wetland. The wetland in the area by the existing farmstead is intended to remain in its current location, though is proposed to be lowered in elevation to maintain hydrology flow to this wetland and to integrate with the proposed grading and stormwater management pond. We have submitted a wetland permit application to the local WCA agencies and will continue our discussions with the WCA agency staff in working towards obtaining a wetland permit. Since the wetland is of lower quality and within a farmed area, we understand the wetland can be impacted and lowered in its current location (up to 8 feet lower), and that won’t require any wetland mitigation (No wetland credits or on-site mitigation). Stormwater Management: Currently the site has two points of discharge, one in the southwesterly corner of the existing school and just to the east of the existing homestead under 122nd St. There is a significant portion draining onto the property from the northern properties. Most of the site and the north offsite drainage drains to the wetland located east of the homestead near 122nd St and drains through two culverts under 122nd St during larger rain events. The existing school building and parking lot drain primarily to the SW corner to a culvert under Keller Ave to the west. Through the development of the site, the City of Hugo and Brown’s Creek Watershed District rules for water quality, rate control, and volume control will be required for the stormwater runoff for the site. The existing drainage patterns are generally intended to remain in place, with most of the site being collected and treated in a stormwater pond located to the east of the Homestead. The current area that drains to the southwesterly corner of the school will remain primarily as is. . Water quality will be achieved by a wet pond scenario and will have an average depth of 4 feet of dead storage to meet the NURP requirements and water quality requirements for the City and Watershed standards. With the existing soils not being conducive to infiltration, re-use of the stormwater is being proposed for this project. The stormwater reuse will irrigate the manicured green areas with stormwater instead of using well water as a primary source. . Based on the reuse calculations, the 100-year storm volume is required to irrigate the green areas, so the volume and rate control for the project will be met via the pond and reuse system. Irrigation pumps will be provided to irrigate the manicured green areas. Grading: The intent for phase 1 is to mass grade the site. Temporary swales will provide drainage from low areas of the project, and the drainage from the northern properties will be conveyed (via drainage swales) to the ponding area in phase 1. Currently, it is assumed the stormwater pond will be constructed for the entire project area, and the overall site appears to be relatively balanced and not likely to require any major import or export of topsoil or structural material other than granular material for the road and building bases. All areas will be seeded and stabilized with seed mixes that are not part of phase 1 and the septic areas will be seeded with a native seed mix.