Influenza causes significant morbidity and mortality globally, and is a virus with pandemic potential.  I will illustrate how concentrations and sequences of influenza in wastewater indicate transmission of various influenza subtypes during the respiratory virus season. Influenza virus can be transmitted through air, but also fomites and water. We have been studying how influenza on fomites and in water is inactivated in the presence and absence of sunlight, using cell culture methods. Influenza deposited on plastic surfaces is highly sensitive to sunlight, where the time required for 99% inactivation under full spectrum simulated sunlight is 0.2-0.3 hours, shorter than for well studied bacteriophage MS2 and Phi6 (2.2-4.2 h and 0.7-0.8 h, respectively). Influenza is also susceptible to sunlight in water where it decays faster in colored wetland water (with ~20 mg C per liter) than clear laboratory buffer, even without correcting for light screening.  Uncorrected decay rate constants in the experimental system with full spectrum simulated sunlight are 80 per hour for influenza in colored water compared to 7 per hour in clear water; Phi6 and MS2 decay rate constants are an order of magnitude lower. We suspect the sensitivity of influenza to sunlight, particularly in colored wetland water, may be related to the susceptibility of its lipid envelope to photochemically produced reactive intermediates.