2010 Toyota Corolla faulty water pumps

The car was purchased new from the dealer, who also does all the routine maintenance and repairs The maintenance is current. I do mostly urban driving, and try to treat the car with care.
In 2012 the water pump began making a bad noise and was replaced.
Yesterday, at the 40,000 mile service (car only had 39,299 miles on it) I was advised that there was a small leak in the water pump and it was replaced under warranty. No other problems were noted with the car.
This means I am having to replace the water pump about every 13,000 miles, which seems excessive. When questioned, the service manager was not able to explain why this is happening.
What should I look at as a possible source for the problem? Does this model have a reputation for bad pumps? Would the replacement equipment a dealer uses be faulty, or cheaply made parts from China?
Thanks for your help.