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

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within a short distance of the roadbed as well as escaping into

the atmosphere. The lead accumulates on the surface of streets

during dry periods and then is transported to surface streams

during periods of runoff (EPA, 1972, 1973). Quite naturally

then, the levels of lead in snow along city roads are roughly

proportional to the traffic volume. Lead bromide chloride has

been shown to be the major lead containing product in automobile

exhaust, with PbC03 and PbO also forming on contact of the exhaust

fumes with snow.

The lead appears to be adsorbed on the particulate present

in the snow, as confirmed by adsorption studies. LaBarre, Milne

and Oliver (1973) conducted a study of the concentration of lead

in snow in an urban center, in order to assess the effects of

snow disposal practices on water quality. They showed the level

of lead in snow along city roads to be roughly proportional to

the traffic volume. Also in sampling of lead concentrations of

snow in 11 city snow dumps the average value was found to be 4.8

ppm. Snow collected from city roofs 325 and 40 ft in height,

contained 0.02 and 0.25 ppm lead, respectively. By comparison,

snow along roads and in snow dumps is severely contaminated with

lead from automobile exhausts, as seen in the following table.

Newton, et al. (1974) presented observations of lead con-

centrations in street runoff. Data from automotive emissions and

knowledge of daily vehicle travel in the Oklahoma City drainage
basin studied provided them with a theoretical value of 0.23 mg/~
based upon uniformity of precipitation over the drainage basin.

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