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WQ3.4 Street Cleaning - Coggle Diagram
WQ3.4 Street Cleaning
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if street sweeping is performed infrequently, in relation to rainfall events, it will not be effective.
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efficiencies are greater, for constituents that behave as particulates
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other parameters
SS1 and SS2, be supplied for the entire study area
SSI, SS0, and SSA, be supplied for each land use category within the study area
SSE, is supplied for each combination of pollutant and land use category
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Street cleaning, for control of solids and trash deposited, performed in urban areas
long been assumed, has a beneficial effect upon the quality of urban runoff
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EPA (NURP) studies generally found, little improvement of runoff quality, unless on a daily basis,
more recent studies indicate, technological advances in cleaning equipment, can produce much better results
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elaborate studies, those of Pitt, street surface loadings carefully monitored, along with runoff quality, to determine the effectiveness of street cleaning
frequent street cleaning, smooth asphalt surfaces, 1 or 2 times/day, remove up to 50 percent, of the total solids and heavy metal yields of urban runoff
more typical cleaning, once or twice a month, <= 5% of these contaminants were removed
Organics and nutrients in the runoff, cannot be effectively controlled by intensive street cleaning, much<=10% removal, even for daily cleaning
because nutrients originate primarily, in runoff and erosion, from off-street areas during storms
In Bellevue, Washington, with a maximum projected effectiveness for pollutant removal from runoff, is about 10 percent
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If the date of the current time step falls within SS1 and SS2, buildup mB metioned in Section 3.3 is modified as follows
- If the current rainfall >0.001 in/hr or, >0.05 inches of snow on the plowable impervious area of the subcatchment or,SSI = zero, then no sweeping occurs
- If the time < SSI, between the current date and the date(when the land use was last swept) ,then no sweeping occurs
- Otherwise, set mB = mB(1 − SSA∙ SSE) for each of the land uses’s pollutants, and set the date when the land use was last swept to the current date