1402 SE EVERETT MALL WAY REGAL CINEMAS 2018-01-01 MF Import

recei�ed and discharged ii� a way that does not adversely afCect the funetion of the ponds for trcatment of the stormwater fiom the L'verett Mall site. Sediment removal is required, prior lo discharge to the vegetated treatment cell of the wetpond, for all runoff entering the cell. 19. Maintenance access shall be provided to stormwater control facilities in accordance with City standards. Ciry standards require m�intenance access to the primary sediment removing facilit�• — either the first cell of a wetpond, o~ pre-treatment wetvault. 20. A geotechnical engineer must evaluate thc dam on Qic soudi side of thc �vestcrly detention pond for structural integnty and safety. 'fhis dam a�;pears to have been constructed more than 3� years ago, and contains a 16-inch cast-iron watcr main that is an important component of the City's water distribution system. The geotechnical engineer shall makc recommendations for structural updates to .he dam necessary to protect the water main and to bring the dam into compliance with current dam safety standards. Maintenance of the dam is tiie responsibility of the Gverett Mall. 21. The plans do not appear to show the correct location of the 16-inch �vater main in the dam area, �i�hich, according to City infonnation, is mucL closer to the north side of the berm than i; currently shown. "rhis �vater main must be located in the ficld and shown in the correct locatior on thc plans. "?2. Thc City would nllow the usc of an SMI StormPilter instead of or in conjunction wiQi a wctpond. Additional criteria for tlie usc of a Stormfilter �vould be as Collo�vs: I) I'hc Stornil�ilter must be preceded by a pretmltment �vetvauldtank containing at least 30% of the 6-month, 24-hour stonn runoff volume from the contributing, developed drainage arca. 2) "l hc StormPiltcr must trcat at Icast the 6-monQi, 24-hour stonn. 3) 'I hc Stornil�iltcr shall be desigued using a maaimum (low rate of 7.5 gpm per cartridge. I�lows excceding the design llow shall be bypassed around the system, but should gcnerally pass tl�rough the pretreatment �vetvaulUtank. -1) I hc Stor�u['ilter media shall target dissolved pollutants and nutrients as �vell as total suspendcd solids. As more eC1'�ctive media become available in ilie future, the Storml'ilter shall be upgradcd, during routine cartridge replacement, to utilize these improvcd media. � i'I he StormFiltcr shnll be designed with a minimum of 2.3 feet ol hcad diflerential bct��een the inverts of the inlet and outlet of the filter. Downstream h}�draulic �:�Iculations will bc performcd to dcmonstrate that downstream conditions ��ill not r��Iucc the hydraulic potential across Ute filter due to back�v�ter cifects. �� i I:��utine �uamtenmice of the StormFilter is mquired. A detailed operation and maintenance plan for the system must be preparcd for approval by d�c City. A certificate o£systcm maintenancc must bc suUmitted to the City annually. ?) Maintenance nnd operation oC thc StormPilter on Uiis site shall bc adnpted, in tl�e future, to reIlcct the current knowlcdgc regarding this cmerging tcchnology. S) All othcr applicab(e, and non-con(lictin�„ criteria in the current edition of SMI's Product Design Manual shall be Collowed in the design, construction, and maintenance of the SMI StormPiltcr o!t this sitc. I. Portions of the existing mall compie� disch�uge to the existing custerly and westerly detention ��onds on thc siic. In these ponds, the storm�vater receives n limited amount of stonmvater ucaunent in addition to detention. Stormwatcr runoff from cxisting areas of the mall complex �chich �iill not bc "redeveloped" as a part oC this projcct must continuc ro receive ut Icast an cyuivalent nmount of storm�vater treahnent as currently occurs. '. Parking must be per City 7_oning Codc and City Design and Construction Stnndards for I)evelopment. �'�f J