According to Pam Kostle, a program manager at the University of Iowa Hygienic Laboratory, a pico is a trillionth, and a curie is 37 billion disintegrations per second of a radioactive element.
Translated, this means that 5 pc/L equals .185 disintegrations per second in a liter of water.A liter is slightly (.06) more than a quart.If a Geiger counter gave one click for each disintegration, a click would be heard every 5-6 seconds from water with 5 pc/L of radium. [Actually, Geiger counters measure gamma radiation, and on a different scale, roentgens per hour, than that of radium on the pc/L scale.]
The higher-than-allowable pc/L reading led the Iowa Department of Natural Resources
to put Fairfield on a quarterly reporting system for a year.