Why am I filling my coolant reserve more than usual?

I recently had my water pump replaced in my 2002 Chevy Trailblazer in October of
2014.  I noticed leakage on my driveway and I originally thought it was oil but talking
with an retired mechanic..it could be coolant.  He noticed that I had a new water pump
and stated it's challenging to install one on the Chevy Trailblazer and could affect the
functionality of the coolant system (leakage and etc.).  He also stated that, it appears
that it leaking close to the fan area due to the coolant being splattered to the hood and
on top of the fan itself because we could not see the leakage while the vehicle was
running with the hood open.  Is it true that due to the difficulty of replacing the water
pump on the Trailblazer can cause leakage?

Ron