Laserfiche WebLink
<br />H:\ORNO\_Surface Water Management\MS4 Administration\MCM-5\2_Site Plan Reviews\Orono Garage Condos\Orono Garage Condos_PrelimPlan.docx <br /> <br />October 29, 2024 <br /> <br />City of Orono <br />Attn: Adam Edwards <br />2750 Kelley Parkway <br />Orono, MN 55356 <br /> <br />RE: Preliminary Plans <br /> Orono Garage Condos <br /> Engineering Review #1 <br /> <br /> <br />Dear Adam: <br /> <br />As requested, we have completed an engineering review of the documents submitted for the above <br />referenced project. Following are my comments for your consideration: <br /> <br /> <br />1. Proposed improvements will require the installation of stormwater runoff management <br />practices to meet Minnehaha Creek Watershed District and NPDES requirements for runoff <br />treatment. The following should be considered regarding stormwater management: <br />a. Not enough information has been provided to determine if the proposed design is adequate. <br />A complete Stormwater Management Plan for the site meeting MCWD and NPDES <br />requirements should be provided for review. <br />b. Per MCWD requirements, the proposed stormwater runoff management system must <br />provide rate control and volume control for the new and fully reconstructed impervious <br />surfaces. For complete MCWD requirements, please refer to the following link: <br /> <br />Regulations - Minnehaha Creek Watershed District (MCWD) <br /> <br />c. Per NPDES requirements, the water quality volume must be treated, calculated as 1” times <br />the sum of the new and fully reconstructed impervious surfaces. If infiltration is prohibited <br />as outlined by NPDES requirements, a wet sedimentation basin or filtration basin may be <br />utilized. For complete NPDES requirements, please refer to the following links: <br /> <br />https://www.pca.state.mn.us/sites/default/files/wq-strm2-81a.pdf <br />https://www.pca.state.mn.us/sites/default/files/wq-strm4-94.pdf <br /> <br />d. The permanent best management practice chosen (infiltration, filtration, or wet <br />sedimentation) must meet the design requirements outlined in the MCWD and NPDES <br />permits. <br />e. Per City requirements to track TMDLs and reduce loads to meet required Waste Load <br />Allocations, the calculations for Total Suspended Solids (TSS) and Total Phosphorus (TP) <br />loading should be included in the report. <br />2. The sanitary sewer capacity provided to the site is sufficient to support the development. <br />3. The water main capacity provided to the site is sufficient to support the development. <br />87