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HomeMy WebLinkAbout2008-07-23 MSCWMO Ltr to OPH1 380 WEST FRONTAGE ROAD, H I G H W A Y 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 Phone 651.275.1136 x22 fax 651 .275. 1254 w w w m s c w m o o r g Jul 23, 2008 Eric Johnson, Administrator Cit of Oak Park Hei PO Box 2007 Oak Park Hei MN 55082 RE: Boutwell's Tunnel/Parkin Lot Dear Mr. Johnson, Stillwater oak Park Hei is 'Ba . si—I I Baytown TV$P MSCW West Lakeland txp Lad e ]arid il., eland ton: ores tak St. E r EP Beach S t Mary's M V t The Middle St. Croix Watershed Mana Or (MSCWMO) received re submittal items on Ma 6, 2008, and additional submittals on Jul 23, 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, meets all Policies and Performance Standards contained within Section 5.0 of the MSCWMO WMP. Final MSCWMO approval is g ranted. This 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 x21 or peter. @ mnwcd.or g 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 55 `h Street North, Lake Elmo, MN 55042 Al Black, Presb Homes, 2845 North Hamline Avenue, Roseville, MN 55113 Am Carolan, MSCWMO Administrator Enclosures ( 2 ) Mi St C r o i x Watershed Mana Or Member C o m m u n i t i e s Afton, Ba Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Et West Lakeland kAVj—=V1kWi W &_AU=UILM F 1 3 8 0 WEST F R O N T A G E R 0 A D Y HIGHWAY 3 6 &k'Park lie 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 ww.mscwm o o r g MSCWM West Lakeland — L lwp MSCWMO PROJECT REVIEW PROCESS — POLICIES AND PERFORMANCE STANDARDS i dye- I and LL L SW 0 r e S 1L71k 'FLAIrl) f aW 1' ti)M 4 This document is for g uidance. Applicants should consult the MSCWMO Watershed -prit s Manaiaement Plan (WMP) for specific re 4­1 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 pro PROJECT NAME: BOUTWELL's TUNNEUPARKING LOT - OAK PARK HEIGHTS MSCWMO POLICIES AND PERFORMANCE STANDARDS: [ A checked box indicates con ot- not a 1'7 Direct dischar of stormwater to wetlands and all other water bodies without water q ualit y V_1J treatment is prohibited. WMP Section 5.1.4, Polic Item I Sources of water pollution shall be identified throu the MSCWMO data collection 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 10- return period event. WMP Section 5.1.4, Polic Item 4 Fq 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, Bayport, Ba Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Hei St. Mar Point, Stillwater, Et West Lakeland Applicants must secure any flowage easements that would be required to accommodate the storm.water management facilities. These easements will be granted up to the 1.00 -yr flood level. WHIP Section 5.1.4, Policy Itein 7 ® Applicants will provide the MSCWMO with loo -year flood levels on the ponds, lakes, and streams as parcels are developed. WMP Section 5.1.4, Policy Item 8 ® The MSCWMO has adopted the Washington County Floodplain Regulations. (Appendix H). WHIP Section 5.1.4, Policy Item. 9 ® Project must meet the Design Standards for Structural Stormwater Management Measures of the State of Minnesota Stormwater Manual, November 2005, or the most recent edition at www.pca.state.mn.us/ water/ stormwater lstormwater- manual.html. WMP Section 5.1.4, Performance Standard 1; WHIP Section 5.2.4, Performance Standard I Design requirements for infiltration basins: ® Adequate pretreatment upstream of infiltration practice(s) ® Construction phased so that impervious area construction is complete and pervious areas have established vegetation before stormwater is introduced into infiltration practice(s) Z Construction phased so that infiltration practice(s) not excavated to final grade until contributing drainage area fully stabilized ® Drawdown time of the infiltration practice(s) 48 hours or less ❑ Planting plan detailing establishment of vegetation suitable for hydrology of basin [not apl)licable — basin already establishedlstabilized] ® Infiltration of runoff from potential stormwater hotspots (PSHs), including industrial areas with exposed significant materials, vehicle fueling areas, and maintenance areas, is prohibited Z Easy access provided for routine maintenance of infiltration practice(s) ® Proposed infiltration area(s) must be marked during construction to prevent heavy vehicle traffic and equipment from traveling over them ® If infiltration practice(s) are present during construction activities, sediment and runoff must be kept from infiltration practice(s) with diversion berrns or other effective BMPs; infiltration areas must never serve as sediment control devices during construction. ® Maintenance plan clearly identifies long -term maintenance schedule and responsibility ® Emergency spillway provided ® Separation from seasonally saturated soils or bedrock is 3 feet or more Z Minimums setbacks from the Minnesota Department of health are met: Setback Minimum Distance (ft) Property line 10 Building foundation* 10 Private well 50 Public water supply well 50 Septic system tank/leach field 35 '=Minimum with slopes directed away from the building Middle St. Croix Watershed Management Organization Member Communities Afton, Bayport, Baytown, Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Heights, S!. Mary's Point, Stillwater, Et West Lakeland Enhanced volume runoff controls will be designed to retain on -site the first 1 /2 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- (4.1.5 inch) and one hundred -year (5.9 inch) critical rainfall events. WMP Section 5.1.4, PerforrncrrTCe Standard 3; WMP 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 1.0,000 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: ® 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 ® Narrative describing the timing for installation of all erosion prevention and sediment control BMPs 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 Standard plates and/or specifications for all BMPs used on the project Middle St. Groin Watershed Management Organization Member Communities Afton, Bayport, Baytown, Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Heights, St. Mary's Point, Stillwater, 8: West Lakeland 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, Performance 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 -5 5 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 1 00-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 100 -year flood elevation, natural. overflow elevation, and lowest floor elevations. WMP Section 5.1.4, Performance Standard 8 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, Et West Lakeland F Buffer zones of unmowed natural vegetation shall. be maintained or created upslope 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 MSCWMO shall require proper erosion and sediment control throughout the watershed to prevent siltation and sedimentation of streams, lakes, wetlands, and other areas of the watershed. WHIP Section 5.2.4 Policy Item .1 ® Both temporary (during construction) and permanent (long- term) erosion control will be required on newt developed or redeveloped land in MSCWMO undertaki y q ng 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 Policy Item 3 [not applicable] Construction is prohibited on slopes greater than 12 percent. Twelve percent (12 %) slopes are defined as lands having average slopes 120 or greater over horizontal distances of fifty feet (50) or more. WIMP 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 upslope 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, Lakeland, L.aketand Shores, Lake St. Croix Beach, Oak Park Heights, St. Mary's Point, Stillwater, Et West. Lakeland