From the Pennsylvania Department of Environmental Protection (PA-DEP).
Scroll down to "Search for Environmental Laboratories" for lists of PA Accredited or Registered Environmental Laboratories in PDF and Excel formats.
Important! For irrigation water, keep your sample chilled, and always ask for an actual number of E. coli in your sample, not just whether or not it meets drinking water standards.
To submit a drinking water sample to Penn State’s laboratory, obtain a Drinking Water Test Kit from your county cooperative extension office or directly from the laboratory. Send your water sample by overnight mail along with $35.00 payment
There is no universally accepted standard for maximum microbial levels in irrigation water. Until this is resolved, consider using either the EPA national recreational water standards, Pennsylvania recreational water standard, or the GlobalGap standards.
Penn State University Extension
PSU School of Forest Resources fact sheet
Note: regulations on the use of chlorine in water in U.S. and Canada may differ.