#16 - Highpointe Crossing Preliminary Plat and OP PUD

Home Browse Search

PAGE 5 of 6 14. The storm sewer system shall be designed to meet all City design standards including RCP pipe materials and maintaining the minimum pipe cover of 3 feet. Drain tile is required as part of the city standard street section at all localized low points in the street. Drain tile considerations may impact the storm sewer design and depth requirements at low points. Per city requirements all storm sewer pipe easements must be a minimum 30‐feet in width. 15. See attached Memo prepared by Bolton and Menk dated June 25, 2024 for additional storm sewer and stormwater management comments. MUNICIPAL WATER SUPPLY 1. Connection to the municipal water system is available near the proposed development in two locations. The applicant will be responsible for connecting to the existing 16‐inch trunk watermain located along Inwood Avenue (CSAH 13). An 8‐inch ductile iron watermain will need to be extended along the new streets into and throughout the development at developer’s sole cost, and to serve each proposed parcel in the Subdivision. 2. A second connection point is required to create a looped watermain system, connecting to the existing 8‐ inch watermain located along Imperial Avenue in the adjacent Lake Elmo Heights neighborhood. This secondary connection will require the installation of a pressure reduction valve (PRV) as the Lake Elmo Heights neighborhood is located in the intermediate pressure zone while the Highpointe OP parcel is located in the high‐pressure zone. 3. The Preliminary Plans show the required watermain improvements to serve the subdivision. The Pressure Reducing Valve (PRV) and vault will need to be relocated so that the valve and vault reside outside of the street pavement surface. Additional drainage and utility easement may be necessary for the revised PRV location. 4. No watermain oversizing reimbursement is applicable for this development. 5. The developer will be responsible to place hydrants and water system valves internal to the site as determined by the Lake Elmo Public Works Director and Fire Department. Hydrant and system valve locations will be reviewed and finalized as part of the final construction plans. WATEWATER MANAGEMENT / SANITARY SEWER 1. The proposed development is located outside of the City designated Municipal Urban Service Area (MUSA) for sanitary sewer service. The developer is therefore responsible to provide wastewater management infrastructure to support the proposed development in perpetuity, including professional management of the system. All sewer infrastructure must be provided at the developer’s sole cost and will remain privately owned and maintained. 2. The City will require the private sanitary sewer collection system to be constructed as a gravity sewer system meeting City design standards even though it will remain privately owned and maintained. All sanitary sewer manholes must be located at the street centerline. Additional manholes may be required to maintain utility pipe alignments centered within the street pavements. 3. Grading revisions are recommended to increase pipe cover over the sanitary sewer run from the wastewater system tanks to ½ way between SSMH‐1 and SSMH‐2. Additional pipe cover is strongly recommended over pipe insulation along this stretch of the conveyance system. 4. The privately owned sanitary sewer collection system will require either a utility easement agreement as prepared by the City Attorney and Public Works Director, or the facility will require a City right‐of‐way permit to address the ongoing ownership and maintenance of the private sanitary sewer collection system located within the public right‐of‐way. 5. A Communal Septic System is proposed to be located in the 200 ft. buffer area, including both the primary and secondary community drain fields. The primary system is shown in the northeast quadrant of the site, with additional area reserved for secondary treatment systems to the west of the primary system. A community wastewater treatment system serving 65 Lots will exceed a 10,000 gpd capacity and will therefore require a NPDES permit and be regulated through the MPCA.