4.3 SR 03-20-2023 - Laserfiche WebLink

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Short-term temporaryT construction de`vatering of surface or ground `vaters mayT be required at the time of construction (depending on current field conditions) to facilitate construction activities (e.g., utilityr installation, etc.). If dewatering is anticipated to exceed 10,000 gallons per dayr oY 1,000,000 gallons per �Tear, the contractor `vill be required to obtain a Water Appropriations Permit from the Department of Natural Resources (iVIDNR) Division of Waters prior to initiating such activities. Measures to avoid, minimize, or mitigate the environmental effects from construction related to dewatering are unknown at this time, and therefore �vill be determined when developing the dewatering plan as required by a Stormwater Pollution Prevention Plan amendment of the NPDES Construction Storm`vater Permit. L�etlands 12 wetland areas, totaling appro�mately 71 acres, were delineated on the main Project site and approved byT the Local Government Unit (CityT of Elk River) of the iVlinnesota Wetland Conservation Act (Minnesota Rules 8420). A Notice of Decision was issued on November 10, 2021 (LGU Project No. W-21-21). Appro�mately 18 acYes of the curYent wetland aYea on site consists of land that had previously been mined as part of a gravel pit These aYeas would meet the defu�irion of an "incidental wetland" undeY Minnesota Admitustrative Rule 8420.0105 and theYefoYe aYe not Yegulated undeY the Minnesota Wetland Conservation Act. Additionally, poYtions of these aYeas have depths up to appro�matelyr 20'. As a Yesult, these aYeas funcrion moYe as deep-wateY habitats YatheY than wetlands. Wetland impacts were avoided to the extent possible during the preliminaryT design phase of the overall site plan (Exhibit A). The final design ��ill attempt to avoid and/or minimize impacts to the extent possible. Should unavoidable impacts remain, the proper permitting processes will be follo`ved in accordance �vith the WCA and/or Section 404 of the Clean Water Act as applicable. This process `vould involve applyTing for a replacement plan potenriallyT requiring compensatoryT mitigation. The area of wetland impact and jurisdictional status of the `vetlands will be determined b�T the proper governmental agencyT during the permitting process follo`ving conclusion of the environmental review process. Other Surface L�a ters No other surface water features (lakes, streams, intermittent channels, or count�T/jurisdictional ditches) will be phyTsicall�r or indirectlyT altered during the construction or operation of the proposed pYoject The only wateY feature located on the project site is the DNR Public Waters �vatercourse Trott Brook `vhich meanders in and out of the project site along its western and southern boundaries. Trott Brook was avoided during the preliminaryT design phase of the overall site plan (Exhibit A). TemporaryT erosion and sediment control best management pYactices (BMPs) will inirially be installed (peY the pYoject's SWPPP), maintained/repaired, and amended throughout the construction phases to avoid indirect impacts to Trott Brook. BMPs may include (but are not limited to) silt fence, bio-rolls/filter logs, rock construction entrances, mulch/hyTdro mulch, and permanent native seeding or turf seeding in appropriate areas. Follo`ving construction, permanent constructed storm`vater treatment infrastructure (e.g. infiltration basins,