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~~ ,fr~~~:~,~,~g ~•aeir of the diversion vault. Far units possessing a sizable depth telotiv grade (depth to pipe), a single manhole access point u~rauld ailava Loth sump cleanout and access behind the screen. CDS Technologies Recommends The Follovaing: NEV16 INSTALLAT{ONS -Check the condition of the unit after every runoff event far the first 3d days. The visual inspection should ascertain that the unit is functioning properly (no blockages or otstructions to inlet andlor separation screen), measuring the amount of solid materials that have accumulated in the sump. the amount of fine sediment accumulated behind the screen, and determining the amount fioa#ing trash and debris in the separation chamber. This can to done vt~ith a calitrated "dip stick" so that the depth of depas~tion can to tracked. Schedules for inspections and cleanout should to based an storm events and pollutant accumulation. C)NGaING CtPERATION - During the rainfall season, the unit should to inspected at least once every 3D days. The floatatles should to removed and the sump cleaned ;avhen the sump is 76-85% full. If flaatatles accumulate mare rapidly than the settleable solids, the floatables should be removed using a vector truck ar dip net before the layer thickness exceeds one to tw~ao feet. cleanout of the CDS unit at the end of a rainfall season is recommended because of the nature of pollutan#s collected and the potential far odor generation from the decomposition of material collected and retained. This end of season cleanout vain assist in preventing the discharge of pore water from the CDS unit during summer months. USE 4F SC}RBENTS - It needs to be emphasized that the addition of sortents is not a requirement far GDS units to effectively control oil and grease from storm vrater. The conventional ail tafF[e within a unit assures satisfactory oil and grease removal. However, the addition of sortents is a unique enhancement capability special to CDS units, enabling increased oil and grease capture efficiencies beyond that attainable by conventional oi{ baffle systems. Under normal operations, CDS units ~.^riil provide effluent concentrations of oil and grease that are less than 15 parts per million (ppm} for a#I dry ~~veather spills ~:ahere the volume is less than or equal to the spi{I capture volume of the CDS unit. During wet ~~aeather flows, the oil baffle system can be expected to remove tefiraeen 40 and 7Q% of the free oil and grease from the storm ti^~ater runoff. CDS Technologies only recommends the addition of sortents to the separation chamber if there are specific land use activities in the catchment •~~vatershed that could produce exceptionally large concentrations of ail and grease in the runoff, concentration levels •~~^rell atove typical amounts. If site evaluations merit an increased control of free oil and grease then ail sortents can to added to the CDS unit to #haroughly address these particular pollutants of concern. Exhibit B-2