Enterococci Populations in Conventional, Manufactured and LID Stormwater Treatment Systems

摘要

Pathogenic microoganisms can cause disease in humans exposed to contaminatedrecreational waters. New Hampshire uses enterococci as the fecal indicator inestuarine and marine recreational waters. Stormwater runoff is the most significantsource of bacterial pollution in NH, and several types of routinely installedstormwater control systems are ineffective for removing enteroocci. This studyaddresses the performance of eleven treatment system designs on enterococcipopulations during storms. Water samples were collected during storms from eleventreatment systems under controlled conditions and enterococci were enumeratedusing EPA method 1101.6. Some systems appeared to be sources while othersappeared to remove enterococci from runoff. Enterococci concentrations exhibitedmarked seasonal trends, peaking in August. These results suggest elevatedenterococci concentrations are present in wet treatment systems between storms,resulting in increased concentrations being discharged into receiving waters withrunoff from storms. Ongoing studies are designed to better characterize enterococcidynamics between storm events.