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� " I <br /> � <br /> A H � � � �. . ' i <br /> b H N <br /> t+ Sy ' <br /> y 'L N � <br /> K y � <br /> � y N . 4 .3 .15.8 other design criteria for grass lined swales: <br /> ea a 25 ye�r design storm <br /> z <br /> o � b) maximum velocity of four Peet per second usir.g <br /> .�ic�v � Mannings Eguation with h=:035 <br /> r�, � c) Maximum flow depth of 5.4 inches. <br /> � H � d) Piaximum side slope of three horizontal to one <br /> M y vert:ical � <br /> � o N e) Longitudinal slope no greater than 5 percent <br /> c� � r f) Minimun £reeboard of six inches j <br /> �° N � <br /> y � y Add: � <br /> 4.3.16 OIL/WATER SEDARATION AND GRIT REMOVAL <br /> � <br /> 4.3.16. 1 For Storm�ater treatment the vault shall provide a <br /> nini*ium of a 15 minute retention time at the rate of • <br /> the vault inlet capacity. <br /> 4.3 .16.2 For Stormwater treatment the vault inlet capacity <br /> shall be determined by use of the rational forn;ula, <br /> Q = cia. The intensity for use in the rational , <br /> formula shall be 0.5 in/hr <br /> 4.3 .16.3 For Stormwater treatment a bypass piping system • . <br /> shall be used to divert excess flow around the vault <br /> �/—�', . when tne inflow rate exceeds the capacity of the , <br /> L� vault inlet. <br /> 4 .3. 16.4 For spill containnent, vaults shall be eguipoed with <br /> � an isolation valve. <br /> I ..,�� 4 .3. 16.5 Spill containment vaults shall discharge into the f <br /> �� sanitary sewer system. . <br /> 4 .3 .16. 6 Spill containment vaults shall provide a minimum ' <br /> "live" capacity of 2500 gallons. <br /> �� 4.3.16.7 Bypass piping shal.l not be allowed for spill ; . <br /> � = � containment vaults. i . <br /> i 4.3 .16.8 Coelescing plates nay be required for sites with a � <br /> high risk of large volume spills or discharges. <br /> �_ f <br /> e� Change: � <br /> 4.3 .10 INFILTRATZON SYSTEDSS to read: i <br /> '' Infiltratio� systems are generally not recommended ' <br /> �� as the so.la means of disposing of Stormwater. <br /> I Aowever, infiltration systems designed to infiltrate <br /> small storms and the first flush of large storms <br /> I ��� while safely overflowing large storm events to an <br /> I ��� established drainage course are recommended as a � <br /> \ means r..`, treating stormwater. <br /> 4 .3.10. 1 Oil/W.:ter separation an3 g:-it removal in accordance <br /> with section 4 .3.16 will be req�iired upstream of all <br /> infiltration systems. Alternatively a wet pond <br /> could be used to remove oil and sediment prior to <br /> discharging to the infiltration system. <br /> � <br />