Microbiological water testing

Thank you for your SOP of water testing. Sir I have 2 uestionsas follow:

  1. in your SOP you have written testing of 4 pathogens. Can you share the reference from where the names are written. As in up no particular organisms are mentioned for water testing. Are these 4 enough?
  2. how you have determined alert and action limits. Any reference for the same available. plz guide us for these topics. Thank you

Reference from USP

USP 1231(WATER FOR PHARMACEUTICAL PURPOSES) this chapter mention all information