are you positive it is the water pump? you said you just replaced the power steering pump.
now, I had this exact problem a couple of years ago with my ford windstar van.I had everything off of the motor to rebuild as it had spun a rod. when I put it all back together I had a aweful squeal. so, out came the stethoscope, I was positive it was the power steering pump (fail), idler pulley(fail ),then the tensioner (again, fail), sounded all the world like the water pump ( again, no fixy) I felt like putting a hammer thru the windshield! then it dawned on me....... I had to take the power steering bracket off of the the motor in order to get the motor out of the car which involed removing the PS pulley.
after replacing all those GOOD parts, turns out I didn't put the PS pulley back on far enough! it looked fine but one more full turn of the pulley installer fixed it. it was off just enough to reek total havoc! oh yeah I also replaced the bearings in the ALT & tried (2) different belts during my quest to find the never ending squeal!
sorry for the long post but wanted to put that out there for consideration.