TABLE 1.

List of treatment facilities sampled during this study and their respective treatment processes

StateDate of collection (mo/day/yr)Treatment
PrimarySecondaryTertiary
Alabama11/5/2007Grit removal via screenAeration basin, secondary clarifierChlorination
California10/18/2007SedimentationActivated sludge systemGravity filters, chlorination
Connecticut11/14/2007SedimentationActivated sludge systemChlorination
Florida11/30/2007NoneAeration basin, secondary clarifierSand filters, chlorination
Florida Keys9/29/2008aGrit removal via screenActivated sludge systemFabric filters, UV irradiation, chlorination
Louisiana11/12/2007NoneActivated sludge systemFinal clarifiers, chlorination
Maine11/5/2007SedimentationActivated sludge systemSand filters, chlorination
Maryland11/24/2007SedimentationRotating biological contactorsChlorination
New Jersey11/13/2007Grit removal via screenActivated sludge systemDeep bed filters, chlorination
North Carolina11/13/2007SedimentationActivated sludge systemMultimedia filters, chlorination
Oregon11/13/2007SedimentationActivated sludge systemChlorination
Washington11/8/2007SedimentationActivated sludge systemChlorination
  • a The Florida Keys treatment plant was sampled approximately every 3 days over a 2-week period (9/29/2008 to 10/11/2008).