Studies of Microbiological Contaminants in surface and ground water in Pennsylvania

• Water from 62% of the wells sampled were positive for total coliform.
  
• Water from 10% of the wells sampled were positive for E. coli.
  
• Total coliform were just as likely in water from sanitary (grouted) wells as they were in nonsanitary (nongrouted) wells.
  
• E. coli were more likely in water from nonsanitary (nongrouted) wells
  
• Carbonate aquifers are more vulnerable to bacteria contamination than noncarbonate aquifers.
  
• Relations exist between the presence of total coliform bacteria and select well-construction characteristics.

 
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The Final Report Online WRIR 01-4206:
Relation Between Selected Well-Construction Characteristics and Occurrence of Bacteria in Private Household-Supply Wells, South-Central and Southeastern Pennsylvania (PDF File)

• Lower Susquehanna River Basin (NAWQA) (Bruce Lindsey blindsey@usgs.gov)
• Viruses in water from wells used for noncommunity supply (Bruce Lindsey blindsey@usgs.gov)
• Relation between Well-Construction Practices and Occurrence of Bacteria in Private Household-Supply Wells in Southeastern Pennsylvania (Tammy Zimmerman tmzimmer@usgs.gov)
• Blue Marsh Lake (Michele Zimmerman mlzimmer@usgs.gov)
• Helicobacter pylori (Michele Zimmerman mlzimmer@usgs.gov)

• Lower Susquehanna River Basin (NAWQA)
  
• Viruses in water from wells used for noncommunity supply
  
• Relation between Well-Construction Practices and Occurrence of Bacteria in Private Household-Supply Wells in Southeastern Pennsylvania
  
• Blue Marsh Lake bacteria source identification pilot project (ongoing project)
  
• Helicobacter pylori
• Bacteria in the Brandywine Creek Watershed