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HomeMy WebLinkAboutRe: engineering review • = BO I_TON 8 . M r-=N K , OR COPY Consulting Engineers & Surveyors 2638 Shadow Lane,Suite 200•Chaska, MN 55318-1172 Phone(952)448-8838•Fax(952)448-8805 www.bolton-menk.com July 17, 2012 City of Orono Attn: Melanie Curtis PO Box 66 Orono,Mn 55323 RE: Building Permit Application 2012-00589 House Construction 125 Turnham Road Dear Melanie: As requested, we have completed an engineering review of the Site Design Plan prepared by Anthony Rochel dated January 31, 2012 submitted for the above referenced project. We offer the following observations,comments, and recommendations for your consideration. Review Comments 1. The information on the Site Design Plan should be added to the Certificate of Survey to create one complete document per City requirements. 2. The Storm Water Pollution Prevention Plan (SWPPP)measures shown on the Site Design plan are acceptable, and the placement of perimeter silt fence according to the SWPPP was verified on July 12, 2012. 3. Minnehaha Creek Watershed District(MCWD)has approved the currently submitted Wetland Buffer Establishment Plan. Therefore,we agree the placement of 6"topsoil in the buffer area and location of Wetland Buffer Markers are acceptable. 4. The remaining comments listed on the letter prepared by Bolton&Menk dated July 16, 2012,but not addressed by this review, should be listed as conditional to the Building Permit approval. Please contact me if you have any questions or need additional information. Sincerely, BOLTON&MENK, INC. Robert E.Bean,Jr.,P.E. Water Resources Engineer ONNOWetland duffer Establishment Plan C A. Site Preparation 1. Next spring, we will allow the site to green up,followed by a spot application of Rodeo' and Garlon 3A1 herbicide as per manufacturer's directions. Care will be taken to avoid any significant stands of desirable vegetation. We will allow a minimum of 20 days before disturbing the vegetation with other procedures. 2. We will then carefully harrow the soil to create an open seedbed. B. Seed and Seeding 1. Seeding dates shall be in the spring or summer before June 301" (seeding may be done as late as August i" if necessary). 2. Once the soil has been prepared, the larger grass seed will be broadcast throughout the project area. 3. A harrowing will follow to incorporate the seed into the soil. 4. Following the harrowing,the smaller grass seed, sedge seed, and flower seed will be sown on top of the soil. No additional harrowing is rewired. 5. The seed mixes shall consist of PAN State Seed Mix 35-241 or approved equivalent from Twin City Seed. Seed rate shall be 36.5 lbs/acre including 25/lbs per acre of oats as a cover crop. C. Erosion Control: 1. Cover crop will be oats at a rate of 25 lbs,/acre and will be sown along with the native grasses. 2. Straw mulch will be used on sloped areas and site will be monitored to determine if more aggressive erosion control measures are necessary. D. Plants and Planting: 1. As a means to create a higher quality restoration,the seeding will be further diversified and enhanced with wildflower,grass and sedge seedlings.These would be planted individually in appropriate microhabitats throughout, or in designated areas of the project. E. Management: 1. Management and monitoring reports will be provided for 5 years. 2. During the first growing season the project area will need to be moved at a height of 6 inches least once to control annual weed development. If a "closed" canopy of weed cover develops, it will be mowed to aid in the growth of the prairie seedlings by reducing competition. 3. In years following the first growing season, site monitoring, burning, mowing, spot spraying, or hand weeding will be completed as necessary to ensure growth of native species. 4. Buckthorn and invasive species will be monitored on an ongoing basis. Manual control will include hand pulling., cutting and wrenching. Herbicides such as Glyophosate will be used as necessary. Narrative A. Schedule a. Begin Construction 2/456022 11P/391Z b. Substantially complete grading activities 3 -71.3olZol0 c. Substantially complete constructior f J/3o/yon L- B. A grading contractor has not been selected,once on is information will be provided C. In order to establish permanent cover,topsoil is to be stripped and respread and seeded Inspection and Notification Agreement: (1)The individual identified as being responsible for implementing the erosion control plan must routinely inspect the construction site once every seven days during active construction and within 24 hours after a rainfall event greater than 0.5 inches in 24 hours. (2)All inspections and maintenance conducted during construction must be recorded in writing and these records must be retained with the erosion control plan and made available at the District's request within 24 hours. Records of each inspection and maintenance activity shall include: (i)Date and time of inspections; (ii)Name of person conduction inspections; (iii)Findings of inspections, including recommendations for corrective actions: (iv)Corrective actions taken(including dates,times and party completing maintenance activities);and (v)Date and amount of all rainfall events greater than 0.5 inches in 24 hours. (b)NOTIFICATION. The applicant or its authorized agent shall notify the District in writing at the following points(large public projects may request alternative notification processes that may include maintenance on an on site written log of the following points): (1)On completing installation of perimeter erosion and sedimentation controls. (2)On completing land-disturbing activities and putting into place measures for final soil stabilization and revegetation. (3)Whenever any site dewatering is proposed to take place. (4)When the site has been permanently stabilized and re-vegetated. (5)When all temporary erosion and sedimentation controls have been removed from the site. Anthony Rochel • = BO ETON M B N K , I NC® Consulting Engineers & Surveyors 2638 Shadow Lane, Suite 200•Chaska, MN 55318-1172 Phone(952)448-8838• Fax(952)448-8805 www.bolton-menk.com July 16,2012 City of Orono Attn: Melanie Curtis PO Box 66 Orono,Mn 55323 RE: Building Permit Application 2012-00589 House Construction 125 Turnham Road Dear Melanie: As requested,we have completed an engineering review of the documents submitted for the above referenced project. Our current review is based on the documents listed below,and we offer the following observations,comments,and recommendations for your consideration. Submittal Documents • Building Permit Application dated June 25,2012 • Certificate of Survey prepared by Gronberg&Associates dated June 14,2012 • Resolution 6117 approving CUP • Wetland Buffer Establishment Plan • MCWD correspondence regarding Erosion Control and Wetland Protection permits Review Comments 1. Per City Council resolution 6117,the following items should be conditional to the approval of the building permit: a. The City Engineer shall be allowed to inspect any fill being brought to the site prior to it being placed. b. The applicant shall work with the City Engineer to locate and install protection around the potential septic areas to insure they are not impacted and compacted during fill activities. The protection fencing location must be inspected and approved by the City Engineer prior to any land disturbing activities other than placement of silt fence. c. The applicant shall confirm with the City Engineer acceptable hours of truck hauling and provide documentation on the haul route to be used. Acceptable hours and haul route must be approved prior to the importing of any fill. d. If fill is imported to the site,the City Engineer shall inspect roadways on haul route prior to and following completion of work to determine whether adverse impacts have occurred. The applicant shall be responsible for the repair to roadways for any adverse impacts. e. The cmp culvert under the driveway is in poor condition,with holes rusted through the top of the pipe. The culvert should be replaced as part of this project,matching existing size and elevations. f. The condition of the driveway and Turnham Road has been documented with digital pictures. A few minor ruts and riffles have been noted on the shared gravel driveway. s - • 125 Turnham Road,Orono,MN July 16, 2012 Page 2 Minor expansion cracking and a few areas of alligator cracking have been noted on Turnham Road. The applicant should be required to review existing conditions and confirm the City's documentation through an initial condition walkthrough. After construction is complete,the City Engineer shall review the condition of the driveway and Turnham Road,and any damage shall be addressed by the applicant. g. The applicant/contractor shall notify the City 48 hours prior to required inspections. 2. This project will disturb more than 25 cubic yards of material. Therefore,a final Storm Water Pollution Prevention Plan(SWPPP)must be submitted for review in accordance with City code. Also,the minimum$2,000 sediment and erosion control financial security should be required for this permit. 3. Perimeter silt fence installation should be inspected by the City prior to any land disturbing activities to ensure compliance with the SWPPP. 4. The Wetland Buffer Establishment Plan should include the following: a. Add note under Site Preparation indicating the placement of minimum 8"clean topsoil on graded areas of the buffer zone to ensure good seeding success. b. Add note under Management to indicate the placement of Wetland Buffer Markers at the upland buffer edge,located at lot lines,change of buffer edge direction,and/or spaced at a maximum 100 feet apart. 5. A copy of the MCWD permit should be submitted prior to any land disturbing activities. 6. Per the conditions of MCWD permit approval,confirmation that the Declaration of Wetland Buffer was recorded with Hennepin County should be submitted to the City prior to any land disturbing activities. 7. Confirmation that the financial assurance for wetland buffer establishment was submitted to MCWD should be submitted to the City prior to any land disturbing activities. Please contact me if you have any questions or need additional information. Sincerely, BOLTON&MENK,INC. �Qg 6444 Robert E.Bean,Jr.,P.E. Water Resources Engineer