03/10/2004 ZONING BOARD OF APPEALS Minutes

Home Browse Search

The following text has been,added to the rias attye, ,.The large infiltration basin, located in the southern portion of the site, is equipped with two cells that are separated by a flow control structure. This flow control structure will be equipped with a concrete weir that has a slot that a wood barrier could be temporarily installed to obstruct flow and locally contain the spill within the forebay. Bioretention facilities also funrction in a manner to localize spills to one area dile to their shallow,depressions and the ms systenothavingpiped outfalls as a discharge ,method. Contaminated soil material then can be excavated and disposed of in an approved offsite location. " 6, It is not clear where rip rap slope protection is to used and how it will be constructed. See response to Comment C:3. 7. Responsible party for operation and maintenance of drainage system. The following text has been added to the narrative: O&V Responsible Party: Association: Main Street Village Housing Association Lettie Lane,Route 130 Mashpee,MA 02649 Association Developed by: McShane Construction, Inca Pill Box 429 Osterville, Mass. 0655 8. Comments on pre to post-development HydroCad`Model. Are building roofs and driveways included in the impervious area calculations? Arewood chip areas modeled as such? Surfaces not covered by forest or grass may increase runoff even further. All building roofs and driveways have been included inthesizing of all drainage structures and have beeli modeled as impervious (CN=98). The site will not be covered with wood chips as the previous application booklet stated. Runoff is increased from Pre to Post-development, however the proposed drainage system provides attenuation and treatment ofstormwater in accordance with state and local regulations. 9. Bioretention systems, rip rap.overflow structures and frozen ground conditions. We have addressed the concerns of how the bioreteuion systems and rip rap overflow structures will function with the updated Plan (Plan View—Sheet 5 and Details_Sheet 6) and the response to Comment, C3. All bioretention facilities have been re'vi'sed to include an emergency overflow system that either discharges to the large infiltration basin to the south of the parcel or to a frozen ground"overflow recharge basin, which are located within the,bioretention areas. .All fi-ozen ground recharge basins are . sized for the 25 year 24-hour storm in Accordance with Town regulations.(see Frozen-Ground Conditions Analysis,.dated March 5, 2004). Response Letter - Horsley Witten Group _ -MainStreet Village (Lettie-Lane)Mashpee,MA ._March 5,2004 Horsley Witten Group <7 `r- .53,9 b: vq'v.']'P .. 1 •Q)U`%C7 �k .