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HomeMy WebLinkAbout2008-07-16 MSCWMO Ltr to OPH^ Stillwater ti MIDDLE ST. CROIX WATERSHED MANAGEMENT ORGANIZATION 1 380 WEST FRONTAGE R 0 A D H I G H W A Y 36 Oak Park Hel 11h - S T I L L W A T E R M I N N E S T 0 A 5 5 0 8 2 P h o n e 6 5 1 2 7 5 1 1 36 x 2 2 f a x 6 5 1 2 7 5 1 2 5 4 w w w rn s c w rn o o r g TVIP i J MSC WW Jul 16, 2008 West Lakeland F- 1W Eric Johnson, Administrator el Cit of Oak Park Hei PO Box 2007 Oak Park Hei MN- 55082 RE: Boutwell's Tunnel/Parkin Lot Dear Mr. Johnson, The Middle St. Croix Watershed Mana Or (MSCWMO) received re submittal items on Ma 6, 2008 for the proposed Boutwell's Tunnel/Parkin Lot project, located within MSCWMO boundaries and in the cit of Oak Park Hei The proposed project q ualifies for full review under the MSCWMO 2006 Watershed Mana Plan ( WMP ) . The project, as submitted, does not meet all Policies and Performance Standards contained within Section 5.0 of the MSCWMO WMP. However,, the project is conditionall approved. The followin conditions must be met: 1. Project must meet the Desi Standards for Structural Stormwater Mana Measures of the State of Minnesota Stormwater Manual, November 2005, or the most recent edition. The followin item must be addressed: a. Drawdown time of the infiltration practice 48 hours or less b. Separation from seasonall saturated soils or bedrock is 3 feet or more The applicant must submit calculations showin that the infiltration basin will have a drawdown time of 48 hours of less from the maximum water level (100- rainfall event The applicant must also submit a cop of the ori plans for the infiltration basin showin that it was desi as stated in the submitted materials. Soil borin information from the ori infiltration basin desi is needed to show that the separation from saturated soils or bedrock is 3 feet or more. Project representatives must submit all re additional information b Au 1, 2008. Final approval will be g ranted when all re additional information has been submitted to the MSCWMO. Conditional approval does not constitute approval b the cit of Oak Park Hei The enclosed checklists contain detailed information on project review q ualification and the policies and performance standards of the WMP. Feel free to contact me at 651-275-1136 x2l or peter. if y ou have an q uestions re these comments. Sincerel Pete Youn En Specialist, Washin Conservation District cc: Vicki VanDell, P.E., Folz Freeman Erickson, Inc., 12445 55th Street North, Lake Elmo, MN 55042 Al Black, Presb Homes, 2845 North Hamline Avenue, Roseville, MN 55113 Enclosures ( 2 ) Middle St. Croix Watershed Mana Or Member Com m unities Afton, Ba Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Ft West Lakeland Stillwater MIDDLE ST. CROIX WATERSHED MANAGEMENT ORGANIZATION I Oak Park "ei . -, r 241 1 380 WEST FRONTAGE ROAD, H 3 6 , -- i L S T I L L W A T E R M I N N E ST 0 A 5 5 0 8 2 ' P h o n e 6 5 1 2 7 5 1 1 3 6 x 2 2 f a x 6 5 1. 2 7 5. 1 2 5 4 w w w m s c w m o r g Bayport saylaw" 1r-- � �Ms,��M,p Lakeland YW MSCWMO PROJECT REVIEW PROCESS REVIEW QUALIFICATION !L& eland loni Ofes Lakeland Y1x , L k S rro B;alll _ , Maly". This document is for g uidance. Applicants should consult the M St SCWMO Watershed nt Mana Plan (WMP) for specific re Each member communit will refer projects to the MSCWMO for full review when deemed necessar based on the activities listed below. Each member communit will adopt the MSCWMO review comments into the member communit comments for each project. PROJECT NAME: BOUTWELL's TUNNEL & PARKING LOT - CITY OF OAK PARK HEIGHTS THE FOLLOWING ACTIVITIES TRIGGER THE MSCWMO REVIEW PROcEss: An project undertakin g radin g , fillin or other land alteration activities that involve movement of earth or removal of ve on g reater than 10,000 s feet of land 0 All ma subdivisions — ma subdivisions are defined as subdivisions with 4 or more lots ❑ An pro with wetland impacts [:] An project with g radin g within public waters F An pro with g radin g within the wetland buffer as identified in the plan F An project with g radin g within 40-feet of the bluff line Redevelopment on a site of 5 acres or more, where pervious surface is disturbed and final impervious surface, in a exceeds I acre or 5% of a site, that causes a chan in runoff characteristics or removal of ve [:] Development pro that impact 2 or more of the member communities Performance Standards in Section 5 of the WMP will appl to development within the Middle St. Croix watershed and focus on stormwater mana erosion and sediment control, and wetland protection. The Performance Standards will appl to all projects that tri the MSCWMO review process. In addition, whenever a project re a buildin permit that add five hundred ( 500 ) s feet of additional impervious surface or a project re a variance from the current local impervious surface zonin re for the propert the Performance Standards will appl Buildin permits for new construction in an approved major subdivision that meets the re of the Performance Standards are exempt from the water q uantit y and q ualit y standards as lon as the individual propert does not exceed impervious surface percenta approved for the g iven parcel in that subdivision. All projects re of whether public or private can be reviewed. Middle St. Croix Watershed Mana Or Member Communities Afton, Ba Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Et West Lakeland MIDDLE ST. CROIX WATERSHED MANAGEMENT ORGANIZATION Elak Park ffvl 1 3 80 W E S T F R O N T A G E R 0 A D H 3 6 S T I L L W A T E R M I N N E S T 0 A 5 5 0 8 2 P h o n e 6 5 1 2 7 5 1 1 3 6 x 2 2 f a x 6 5 1. 2 7 5. 1 2 5 4 w w w. rn s c w rn 0 0 r layport MSCW MP West Lakeland zn MSCWMO PROJECT REVIEW PROCESS POLICIES AND PERFORMANCE STANDARDS .La eland ms L W t C � West "Pl4f t " T , 'Orfs LAO St. 'tin Beach St Mar This document is for g uidance. Applicants should consult the MSCWMO Watershed nt Mana Plan ( WMP ) for specific re All re of the policies and performance standards contained within Section 5 of the WMP must be met before the MSCWMO Board will approve the project. PROJECT NAME: BOUTWELL's TUNNEUPARKING LOT - OAK PARK HEIGHTS MSCWMO POLICIES AND PERFORMANCE STANDARDS: [A checked box indiccites com ot• not ap Direct dischar of stormwater to wetlands and all other water bodies without water q ualit y treatment is prohibited. WMP Section 5.1.4, Polic Item I r7 Sources of water pollution shall be identified throu the MSCWMO data collection E-111 pro and corrected throu the application of BMPs. WMP Section 5.1.4, Polic Item 2 All h studies shall anal the 24-hour two- (2.75 inch), ten- (4.15 inch) and one hundred- (5.9 inch) critical rainfall event, with the critical duration defined as that event causin either the hi water surface elevation or the lar peak dischar in an area or both. An stud must use consistent methodolo for the pre-development and post- development land use conditions. The methodolo must be approved b MSCWMO. WMP Section 5.1.4, Polic Item 3 Newl developed or redeveloped areas will be limited to the predevelopment or existin rate of runoff or to a rate within the capacit of downstream conve s Whichever is less, and no increase in the volume or rate of runoff from newl developed areas will occur in areas where natural outlets do not exist. In sub-areas of a landlocked watershed, development shall not increase the predevelopment volume or rate of dischar from the sub-area for the I 0- return period event. WMP Section 5.1.4, Polic Item 4 Runoff will be minimized throu on-site infiltration or prevented throu reduction in impervious surfaces to the lar extent possible before detention ponds are used. WMP Section 5.1-4, Polic Item 5 Site desi practices that ma have onl a minor ne impact on peak flow and volume, such as the use of buffer strips alon receivin waters and draina swales, will be promoted to achieve compliance with the water q ualit y performance standard. WMP Section 5.1.4, Polic Item 6 Middle St. Croix Watershed Mana Or Member Communities Afton, Ba Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Et West Lakeland r�71 Applicants must secure an flowa easements that would be re to accommodate the 1e_^J stormwater mana facilities. These easements will be g ranted up to the 100- flood level. WMP Section 5.1.4, Polic Item 7 Applicants will provide the MSCWMO with 100- flood levels on the ponds, lakes, and streams as parcels are developed. WMP Section 5.1.4, Polic Item 8 Z The MSCWMO has adopted the Washin Count Floodplain Re ( Appendix H WMP Section 5.1.4, Polic Item 9 Pro must meet the Desi Standards for Structural Stormwater Mana Measures of the State of Minnesota Stormwater Manual, November 2005, or the most recent edition at www.pca.state.mn.us/water/stormwater/stormwater-manual.html. WMP Section 5.1.4, Per Standard 1; WMP Section 5.2.4, Per Standard I Desi re for infiltration basins: Ade pretreatment upstream of infiltration practice(s) Construction phased so that impervious area construction is complete and pervious areas have established ve before stormwater is introduced into infiltration practice(s) Construction phased so that infiltration practice(s) not excavated to final g rade until contributin draina area full stabilized ❑ Drawdown time of the infiltration practice(s) 48 hours or less ❑ Plantin plan detailin establishment of ve suitable for h of basin [not applicable — basin alread established /stabilized] Infiltration of runoff from potential stormwater hotspots (PSHs), includin industrial areas with exposed si materials, vehicle fuelin areas, and maintenance areas, is prohibited Eas access provided for routine maintenance of infiltration practice(s) Proposed infiltration area(s) must be marked durin construction to prevent heav vehicle traffic and e from travelin over them If infiltration practice(s) are present durin construction activities, sediment and runoff must be kept from infiltration practice(s) with diversion berms or other effective BMPs; infiltration areas must never serve as sediment control devices durin construction. Maintenance plan clearl identifies lon maintenance schedule and responsibilit Emer spillwa provided ❑ Separation from seasonall saturated soils or bedrock is 3 feet or more Z Minimum setbacks from the Minnesota Department of Health are met: Setback Miniinum Distance (ft) Propert line 10 Buildin foundation* 10 Private well 50 Public water suppl well 50 Septic s tank/leach field 35 Winimum with slopes directed awa from the buildin Middle St. Croix Watershed Mana Or Member Communities Afton, Ba Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Et West Lakeland ® Enhanced volume runoff controls will be designed to retain on -site the first 1 /z inch of runoff for all impervious areas plus 1 /4 inch of runoff for areas with compacted soils. WMP Section 5.1.4, Performance Standard 2 a. Impervious areas or surfaces are defined as a surface in the landscape that impedes the infiltration of rainfall and results in an increased volume of surface runoff. b. Compacted soils are defined as surfaces in the landscape where the underlying soils are compacted by construction or other activity that impedes the infiltration of rainfall and results in an increased volume of surface runoff. c. In redevelopment scenarios, volume control standards apply only to areas of new construction, where soils are compacted, runoff characteristics are changed, or vegetation is removed. ® No increase in rate of runoff leaving the site from pre- development to post - development conditions generated by the 24 -hour two- (2.75 inch), ten- (4.15 inch) and one hundred -year (5.9 inch) critical rainfall events. WMP Section 5.1.4, Performance Standard 3; WHIP Section 5.2.4 Performance Standard 2 A Stormwater Pollution Prevention Plan (SWPPP) that meets the National Pollutant Discharge Elimination System (NPDES) requirements must be submitted to and approved by the MSCWMO for all projects undertaking grading, filling, or other land alteration activities which involve movement of earth or removal of vegetation on greater than 10,000 square feet of land (See Appendix J for NPDES requirements). WMP Section 5.1.4, Performance Standard 4; WMP Section 5.2.4, Performance Standard 3 SWPPP Requirements: Z Description of the nature of the construction activity • Address the potential for discharge of sediment and/or other potential pollutants from the site • Identify a person knowledgeable and experienced in the application of erosion prevention and sediment control BMPs Who will oversee the implementation of the SWPPP and the installation, inspection and maintenance of the erosion prevention and sediment control BMPs before and during construction • Identify who will have the responsibility for long -term operation and maintenance of the permanent stormwater management system • Identify a chain of responsibility with all operators on the site to ensure that the SWPPP will be implemented and stay in effect until the construction project is complete, the entire site has undergone final stabilization, and a Notice of Termination has been submitted to MPCA Z Narrative describing the timing for installation of all erosion prevention and sediment control BMPs Z Location and type of all temporary and permanent erosion prevention and sediment control BMPS along with procedures to be used to establish temporary BMPs as necessary for the site conditions during construction Z Standard plates and/or specifications for all BMPs used on the project Middle St. Croix Watershed Management [organization Member Communities Afton, Bayport, Baytown, Laketand, Laketand Shores, crake St. Croix Beach, Oak Park Heights, 5t, Mary's Point, Stillwater, E Vilest Laketand Site map with existing and final grades, including dividing lines and direction of flow for all pre and post - construction stormwater runoff drainage areas located within the project limits ® Site map including impervious surface areas and soil types; area of each must be noted (in square feet or acres) ® Location of areas not to be disturbed Location of areas where construction will be phased to minimize duration. of exposed soil areas Identify all surface water and wetlands within 1 /2 mile of the project that will. receive stormwater runoff from the construction site ® Methods to be used for final stabilization of all exposed soil areas ® Describe procedures to routinely inspect the construction site (once every 7 days and within 24 hours after a rainfall event greater than 1 /2 inch) Describe practices to properly manage and dispose of solid waste Describe practices to properly manage hazardous materials ® Describe practices for external washing of trucks and other construction vehicles (concrete trucks, etc.) ® Describe spill prevention plan ® Describe measures to address sanitary and septic waste ® Direct discharge of stormwater to wetlands and all other water bodies without water quality treatment is prohibited. WMP Section 5.1.4, Perforniance Standard 5 ® Predevelopment conditions shall assume "good hydrologic conditions" for appropriate land covers as identified in TR--55 or an equivalent methodology. The meanings of "hydrologic soil group" and "runoff curve number" are as determined in TR -55. However, when predevelopment land cover is cropland, rather than using TR -55 values for cropland, the following runoff curve numbers (RCN) shall be used. These curve numbers represent midrange values for soils under a good hydrologic condition where conservation practices are used and are selected to be protective of the resource waters. WMP Section 5.1.4, Performance Standard 6 Hydrologic Soil Group I Runoff Curve Number A 56 B 70 C 79 D 83 ® Conversion of high - permeability soils shall be avoided and these soils shall be targeted for infiltration. WMP Section 5.1.4, Performance Standard 7 ® Lowest floor elevations of structures built adjacent to stormwater management features and other water bodies must be a minimum. of two feet above the 100-year flood elevation and a minimum. of two feet above the natural overflow of landlocked basins. The landowner or developer is required to provide MSCWMO with the location of the 1.00-year flood elevation, natural overflow elevation, and lowest floor elevations. WMP Section 5.1.4, Performance Standard S Middle St. Croix Watershed Management Organization Member Communities Afton, Bayport, Baytown, Lakeland, Lakeland Shores, Lake St:. Croix Beach, Oak Park Heights, St. Mary's Point, Stillwater, 11 West Lakeland ❑ Buffer zones of unmoved natural vegetation shall be maintained or created upsiope of delineated wetland edges, ordinary high water elevation, or floodplain of all water bodies (wetlands, streams, lakes) in accordance with the Performance Standards relating to wetlands, Section 5.3.4. WMP Section 5.1.4, Performance Standard 9 [not applicable] Detention facilities will be designed to attenuate peak flows and provide on -site infiltration in high - permeability soils, natural depressions, and swales. WMP Section 5.1.4, Performance Standard 10 The MSCWlIMO shall require proper erosion and sediment control throughout the watershed to p revent siltation and sedimentation of streams, lakes, wetlands, and other areas of the watershed. WMP Section- 5.2.4 Policy Item 1 Both temporary (during construction) and permanent (long -term) erosion control will be required on newly developed or redeveloped land in MSCW MO undertaking grading, filling, or other land alteration activities which involve movement of over 100 cubic yards of earth or removal of vegetation on greater than 10,000 square feet of land. WMP Section 5.2.4 Policy Item 2 Existing agricultural activities will be exempt from the performance standards listed in WMP Section 5.2.4. MSCWMO will require buffers from waterbodies and support agricultural BMPs. New agricultural activities must conform to the performance standards listed in WMP Section 5.2.4. WMP Section 5.2.4 Police Item 3 [not applicable] Construction is prohibited on slopes greater than 1.2 percent. Twelve percent (12 %) slopes are defined as lands having average slopes 12% or greater over horizontal distances of fifty feet (S0) or more. WMP Section 5.2.4 Performance Standard 4 Construction is prohibited within 40 feet of the top of blufflines in urban areas and 100 feet in rural areas. Blufflines are defined as a line along the top of a slope connecting points at which the slope, proceeding away from the waterbody or adjoining watershed channel, becomes less than twelve percent (12%). The location of the bluffline shall be certified by a registered land surveyor or the zoning Administrator. WMP Section 5.2.4, Performance Standard 5 Land alteration activities are prohibited within twenty (20) feet of the top of the bluff. Top of bluff is defined as the highest point of a bluff with an average slope exceeding 12 %. WMP Section 5.2.4, Performance Standard 6 Buffer zones of unmowed natural vegetation shall be maintained or created upsiope of delineated wetland edges, ordinary high water elevation, or floodplain of all water bodies (wetlands, streams, lakes) in accordance with the Performance Standards relating to wetlands, Section 5.3.4. WMP Section 5.2.4 Performance Standard 7 [not applicable] Middle St. Croix Watershed Management Organization Member Communities Afton, Bayport, Baytown, Laketand, Laketand Shores, Lake St. Croix Beach, Oak Park Heights, St. Mat Point., Stillwater, Et West Lakeland