Joe Cotruvo answered the dose ...

Joe Cotruvo answered the dose requirement and chlorine sources that can be used.  However, the application depends on the system.  Is this a well that pumps water to a large storage tank?  Is this a manual well that people pump the water from themselves?  The application will determine the appropriate technique.  For a well that feeds a large tank, the simplest method is a venturi injection system.  When the well comes on the dose is consistent as long as there is a chlorine supply (tablet feeder, chlorine bleach tank, on-site generator, etc.).  If individuals are manually treating the water and have their own source of chlorine, then they need the appropriate measuring devices for bleach or chlorine tablets, etc.  Of course I am biased here, but we sell an individual or family sized 4 oz. (108 g)  small hand held electrochlorinator that operates from the on-board solar panel or USB port.  300 liters treated per charge and the device has 1, 2, 5, 10, and 20 liter settings.  The device (H2gO Purifier) automatically produces the appropriate dose (2.5 mg/L) for the volume selected.  No measuring required. Simple to use.  lasts 10 years.  Built to military specs.  www.aquaresearchllc.com.