A method of treating a liquid, the method including: receiving a chemically treated liquid passing the chemically treated liquid through a nanobubble generator to produce a nanobubble-containing liquid treating the nanobubble-containing liquid with disinfecting radiation to produce a resultant liquid and releasing the resultant liquid for use. A liquid treatment system including: a source of liquid a chemical treatment station to test the chemical content of the source liquid and, if necessary, provide an appropriate amount of chemical treatment to the liquid to provide a chemically treated liquid a nanobubble generator in fluid communication with the chemical treatment station that generates nanobubbles to provide a nanobubble liquid a radiation-based disinfecting unit (RDU) in fluid communication with the nanobubble generator that exposes the nanobubble liquid to radiation and provides treated liquid a pump to produce a liquid flow through the system and an outlet through which the treated liquid flows.
