Loading...
HomeMy WebLinkAbout2008 CommunicationsP�THE LPA GROUP INCORPORATED G 15 Crescent Executive Court, Suite 200 Lake Mary, FL 32746-2146 407-306-0200 407-306-0460 (fax) LETTER OF TRANSMITTAL DATE: November 18, 2008 ADDRESS: 202 Airport Drive East PROJECT #: TA412026 Sebastian, Florida 32958 TO: Joe Griffin RE: Sebastian Municipal Airport/Hangar A/RAI Submittal Application No. 40-061-68172-11 WE ARE SENDING YOU: x Attached Under Separate Cover Via: THE FOLLOWING ITEMS Shop Drawings Change Order Specifications Addendum Plans Prints Copy of Letter X Other COPIES DATE DESCRIPTION 1 11-18-08 RAI Response Letter 1 11-18-08 RAI Submittal #1 Design Computations and Updated Construction Plans THESE ARE TRANSMITTED (as checked below): For Approval Approval as Submitted Resubmit For Your Use Approval as Noted Submit X As Requested Returned for Corrections Return For Review and Comment Returned after Loan to LPA For Bids Due COPY TO: SIGNED: loz�f If enclosures are not as noted, kindly notify us at nce. Copies for Approval Copies for Distribution Corrected Prints §LrATHE LPA GROUP INCORPORATED Transportation Consultants 615 CRESCENT EXECUTIVE COURT ■ SUITE 200 a LAKE MARY, FLORIDA 32746-2146 ■ 407-306-0200 ■ FAX 407-306-0460 November 18, 2008 Gretchen Reinertson Engineer, Department of Water Resources St. John's River Water Management District 525 Community College Parkway S.E. Palm Bay, FL 32909 Subject: Sebastian Municipal Airport/Sebastian, FL Hangar A/RAI Submittal Application No. 40-061-68172-11 Dear Ms. Reinertson: 1) The application fee for a Standard ERP is $1000, and a check for $350 was received with your application. Please submit the remaining balance of $650 by check payable to the St. Johns River Water Management District. Please find the attached payment of $650.00 2) The conceptual permit divided the site into eight primary drainage basins. Please identify the basin that the proposed project is located, and demonstrate the proposed project complies with the water quality and water quantity parameters conceptualized under the previous permit. Additional comments may be forthcoming upon receipt and review of your responses. The proposed project is located within primary drainage basins C and D. Please seethe attached Overall Drainage Map. In the Staff Report of the Conceptual Permit application #4-061-68172-5 it states, "The proposed conceptual surface water management system will utilize the existing pond, ditch, and pipe system as well as new wet detention ponds and dry retention areas to be located in each of the previously described basins. These ponds and retention areas will provide water quality treatment and peak rate attenuation for the mean - annual, 24-hour and 25 year, 24-hour design storm events. " The proposed project has one on-line dry retention area which requires water quality treatment and attenuation. Please see the attached Design Computations which have been revised to provide an additional 50% of water quality treatment due to sensitive receiving water, attenuation of the pre vs. post requirement, and recovery of the dry pond within 72 hours. There is an earthen weir located on the proposed pond to serve as an emergency overflow. Please see the attached grading and drainage plan for details of the control structure. ATLANTA ■ BALTIMORE ■ BATON ROUGE ■ CHARLOTTE ■ COLUMBIA ■ FALLS CHURCH ■ GREENSBORO ■ IRVINE ■ JACKSONVILLE ■ KENNESAW ■ KNOXVILLE LITTLE ROCK ■ MOBILE ■ NASFMLLE ■ OCEAN SPRINGS ■ ORLANDO ■ RALEIGH ■ SARASOTA ■ TALLAHASSEE ■ TAMPA ■ WEST PALM BEACH Gretchen Reinertson, Page 2 3) Please submit an exhibit that shows the flow path of water after discharge through the existing 10-inch culverts downstream of the proposed pond. The proposed project discharges to the Sebastian River, which then ultimately discharges to the Indian River. The Indian River is classified as a Class II and OFW. Please seethe attached Overall Drainage Map. Please see attached Design Computations which provide an additional level of treatment for the system since it ultimately discharges to a Class II and OFW 4) Please submit a geotechnical report that includes soil borings extracted from the proposed pond area. Include soil profiles, permeability results, and estimates of the seasonal high groundwater level to support the aquifer characteristics applied to the recovery analysis. Please see attached KSMEngineering geotechnical report. Drainage calculations have been changed to reflect the updated geotechnical information in the infiltration calculations. Please see attached Design Computations. 5) Please submit a topographic survey signed and sealed by a Professional Surveyor registered in the State of Florida. Please see attached Yelcon Surveying plans. 6) Please identify the project benchmarks and vertical datum on the plans. Please see attached Yelcon Surveying plans. 7) It appears from the elevations shown on the permitted plans for the permit #42-061- 68172-8 that the eastern parking spaces will not drain into the existing retention ponds as intended. The proposed elevations are lower than the adjacent pavement elevations shown in the pervious permit plan set. Please revise the grading/drainage as needed. Please see attached Yelcon Surveying plans for the elevations of the existing parking spaces. The proposed elevations have been revised and will drain to the existing retention pond. Please see attached Grading and Drainage Construction Plans. Sincerely, THE LPA GR IN RPORATED Mark C. Jansen, P.E. Project Manager File TA412026.1 g