if you can wait till things dry out or dry them with a heater or hair drier I would place a brown paper towel under the pump and turn it on just long enough to pressurize the system. If the leak is from the pump or the connection near it the towel will show it. You will have to unbolt the pump mounting to get the towel under it.
It looks like the plastic is still on top of the rug so the this test should not see water that is under the plastic, which will take months to dry if left under there.
You may want to poke around in the area and through the plastic with an ice pick to test the subflooring.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles