What is the required free chlorine level after a loose fecal accident?

The correct answer is 20 ppm. In the event of a loose fecal accident in a pool, the Environmental Protection Agency (EPA) guidelines recommend raising the free chlorine level to an elevated concentration to effectively inactivate pathogens such as Giardia and Cryptosporidium that may be present. Setting the free chlorine level to 20 ppm for a sufficient duration ensures that any harmful microorganisms are effectively neutralized, thus maintaining the safety and sanitation of the water.

This heightened chlorine level is a temporary measure that is critical in preventing the spread of waterborne illnesses that could arise from fecal contamination. Once the appropriate disinfection process has taken place and the water is deemed safe, the chlorine concentration can then be adjusted back to the normal operating levels.