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

as Bryan and Colston did, sub-basins, consisting of different

land use patterns, were identified and monitored. The results

of the study are summarized in Table 16 using data from all of

the storms sampled. It was found that:

TABLE 16

Average Peak Concentrations of Pollutants for All Storms Sampled by Rimer,
Reynolds and Nissen, Durham, North Carolina
(Rimer, Reynolds and Nissen, 1976)

Percent Average Peak Concentrations (mg/~)
Impervious
Land Cover Type Area COD SS TP Pb
Low Activity Rural 2.7 41 284 1.40 < 0.1
High Activity Rural 5.1 58 416 0.76 < 0.1
Low Activity Commercial 12 87 575 0.83 0.2
Low Activity Residential 16 166 664 0.84 0.6
High Activity Residential 32 194 1199 1.03 2.1
High Activity Commercial 35 320 1082 1.08 1.7
Central Business District 80 336 528 0.66 O.g

(1) COD levels in stormwater runoff were generally a

function of the amount of development and impervious surface

within the catchment being drained. Increasing values of COD

concentrations can be expected from land cover types which have

an increasing percentage of impervious surfaces.

(2) Suspended solids concentrations were also found to

increase as the percentage of impervious surfaces increases.

Rural areas were found to have the lowest suspended solids

concentration of any of the land uses investigated. The rela-

tively low peak suspended solids concentration in the central

37

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