2001 Bonneville SSEi leaking condensate onto pass side floor

2001 Pontiac Bonneville SSEi, 80,000 miles, wife's daily driver, primarily interstate miles (35 one way) into Atlanta & back. About a week ago began leaking water - not radiator coolant - into the passenger footwell, saturating carpet. Pulled the carpet back, dropped one panel (2 screws) from beneath the glove compartment, no obvious leaks. A/C blows real cold, condensate does drip from beneath the vehicle when parked. Checked the cabin air filter, it's clean & dry.
Thoughts? Any assistance would be appreciated.