HP7 Persistent Organic Pollutants (POPs)
201 Oregon Ballroom
1:20 PM - 5:20 PM, Thursday
() Organic contaminants from highway stormwater runoff.
Hwang, H-M1, Young, TM1, 1 Civil & Environmental Engineering, University of California, Davis
ABSTRACT- Stormwater runoff from urban, agriculture, and highway can produce pulses of contaminants in the receiving water bodies and these pulses may disturb the health of the streams, rivers, lakes, and estuaries. To investigate the input from highway stormwater runoff, organic contaminants listed in California Toxic Rules and Regulations were measured in water samples collected at the edge of 4 different highways in CA. Total dissolved PAH concentrations in precipitation samples ranged from 49 to 172 ng/L. Estimated PAH fluxes for each rain event varied from 0.25 to 3.51 mg/m2 and the total PAH flux was 63 mg/m2/yr. Dissolved PAHs in highway runoff samples, collected at a site on Interstate 80 between Fairfield and Vacaville, CA, ranged from 259 to 1,280 ng/L. The estimated annual loading of dissolved PAHs from the highway was 236 mg/m2/yr. Selected PAH ratios and PAH distribution patterns indicated both pyrogenic and petrogenic sources in precipitation and runoff samples. Lindane was only found in samples collected at a site near maintenance yard of Caltrans, Fairfield, CA. Half of the samples had lindane levels above ambient water quality guidelines (19 ng/L). The levels of chlorinated pesticides showed no apparent relationship with traffic volumes. The concentrations of total phthalates in dissolved phase ranged from 297 to 4,950 ng/L and were likely related to traffic volumes. Tire rubber would be a major source of phthalates. Butylbenzyl phthalate was the most abundant compound among measured phthalates. Total suspended solids in samples decreased exponentially from 1,100 mg/L (first rain event) to 51 mg/L (last rain event). It indicates a possible annual cycle of particle accumulation on the highway during dry weather condition and wash-off during wet weather condition.
Key words: Highway, Stormwater runoff, Organic contaminants, Suspended solids