Analysis of Water Quality and Pollutant Load First Flush of Highway Stormwater Runoff

Water quality and pollutant load first flush of the stormwater runoff from highways with different surrounding environment are investigated in Guangzhou area. The results indicate that oil and grease,CODCr,suspended solids and heavy metals are the dominant pollutants in highway runoff.The biodegradability of the runoff water is substantially low.The levels of oil and grease,CODCr,suspended solids and Pb remarkably exceed the limits of Chinese surface water quality standard class Ⅲ.Although the pollutant levels in runoff from Guangzhou urban highway are comparable to the investigation results of other cities in China,it is higher than all results reported in the developed countries.Quality of the runoff from non-urban area is better than that from urban area.Surrounding environment is the essential factorinfluencing the quality of highway runoff.Load first flush clearly exists for all dominant pollutants in highway runoff.About fifty to sixty percent of the CODCr,suspended solids and heavy metals addition with thirty to forty percent of the oil and grease,BOD5can be removed from highway runoff by intercepting and treating first thirty percent of the runoff water