FLOOD03246

• County: Statewide
• Community: Nationwide
• Basin: Statewide
• Title: Pollution Characteristics of Stormwater Runoff Completion Report
• Date: 9/1/1978
• Prepared By: CSU Environmental Resources Center
• Floodplain - Doc Type: Educational/Technical/Reference Information

Chicago study, other researchers have investigated the charac-

teristics of catch basins, and in each case it was found that,

unless they are cleaned between storms, catch basins are surely

a significant source of pollution during storm events (Lager

and Smith, 1974)

D. Catchment Area Land Use Effects

In recent years, several investigators have conducted studies

to assess the variations of stormwater runoff quality with varia-

tions in land use. In 1972, McElroy and Bell conducted a field

study of stormwater runoff from a small urban watershed and a

larger semi-urban/rural watershed. The urban watershed was a

29 acre (12 ha) fully-developed residential area having 33 percent

impervious area and containing 72 single-family dwellings with a

total population of 252 persons (8.7 persons/acre). Sampling of

stormwater drainage from this area was conducted in a concrete

pit receiving runoff from the storm sewer system. The semi-

urban/rural watershed had an area of 292 acres (118 ha) and

included 178 acres (72 ha) of partially developed residential

land (3.4 persons/acre) (8.4 persons/ha), and 292 acres (118 ha)

of farm land. Sampling of this area was performed in a drainage

ditch.

It was found in the study that the concentrations of

pollutants resulting from the runoff from one acre of urban

watershed were much greater than those from the larger semi-

urban/rural watershed. The ranges of the peak concentrations

are shown in Table 12. Both minimum and maximum peak values

31 .

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