8130 EVERGREEN WAY BASE FILE 2018-01-01 MF Import

Temporary Eroslon Sediment Control (TESC) A temporary erosion sediment control plan has been generated to inciude a stabilized construction entranr,e, catch basin protection and silt fence where necessary. In addition, sound construction practice and specific measures should be taken to ensure that no soil or contaminated water leaves the site. 'o insure this, notes have been added to the documents to address guidelines and requirements for site protection and clean up during construction. • The TESC Notes require the Contractor to address the cor.trol of construction-generated pollutants including sediment laden runoff and air pollution. The site should be monitored during and after large storm events. The TESC Plan is considered minimum requ!rements for BMP and extra measwes may be required to prevent excessive erosion during large storm events. Pem�snen4 Stormweber Plan The detention system is designed per the requirements in City of Everett Stormwater Management Manual to detain the two, ten and one hundred-year developed design storm events and release stormwater at a rate of one-half the two, the ten and the one hundred-year, twenty-four hour, pre-developed design s?orm events. Proposed release rates: Qs.,��. = 0.04 cfs Qio-r�e� = 0.16 Cf5 Qioo-yea, = 0.36 cfs (referto hydrographsin Appendix A) The stormwater management system wili include catch basins and pipes to collect and convey runoff from the impervious area to the proposed detention system. The det�ntion calculations show that a trapezoidal pond"5�t-long-by 21'fee�wide will be needei to meet the required release rates. The correction�faPtoF-bas�mpervious cover is C.42. The design of the detention pond is provided in� ndix A. �c;v�a � {�c�cf I -,,�-i-l„ �•�cl w'.c( f�, eICCGUn r; 1�!' -��n.�_ C.C;rr r=� .I-.-r) Ur..iv:�'l,P , May 2003 20(6 A6KJ, Inc. /S