Studies of Microbiological Contaminants in surface and ground water in Pennsylvania

• 146 Domestic Supply wells sampled for bacteria.
  
• Bacteria were found in 80% of the wells sampled
  
• 70% of the samples were positive for total coliform
  
• 25% of the samples were positive for fecal coliform
  
• 65% of the samples were positive for fecal streptococcus
  
• E. Coli were found in water from 30% of the 88 wells
  
• Bacteria were more likely in water from wells in agricultural areas
  
• Bacteria were more likely in water from wells in the Ridge and Valley Province
  
• E. Coli concentrations were higher in areas underlain by carbonate bedrock
  
• Weak relations exist between bacteria concentrations and selected well characteristics and selected water-quality constituents

Report online
http://pa.water.usgs.gov/reports/wrir_96-4212/report.html

• 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