Selvakumar and Borst (2006) Selvakumar A. & Borst M. 2006. Variation of microorganism concentrations in urban stormwater runoff with land use and seasons. J Water Health (2006) 4 (1): 109–124. Samples from a total of 14 rainfall events were collected. Year 2000 an 2001. over 2 years.