if the tank is empty to begin with, and the volume going in will be less than the tank volume....you could measure the level in tank at the beginning and end and calculate the storage volume.
I should have been clearer about the question, CT (concentration/time) for disinfection. Under EPA SWTR there needs to be calculations done regarding contact time and log removal. Is there software that does those calculations using the inputs of pH, temp, etc.?
Is there a minimum UV dose required by the EPA for disinfection of treated wastewater? I have found literature suggesting 40 mJ/cm2 for drinking water, but am looking for requirements regarding wastewater.
Is NSF certification required by the USEPA for pipes used to convey drinking water? Or is it up to the states to determine what certifications are necessary?