When moving to a new area, or just stuck for a referral, I recommend using a national contractor referral service. Angies List, is the best, largest, and most used site for this purpose. Join Angies List and look up contractors for any purpose, as well as other service professionals in your area.
Subscribers log experiences with contractors, and rate them in categories for performance and evaluation of their talents, if any.
Whether you are moving to a new area, or have lived there all your life, you will find out who is at the top of their game in your area.
So, try it. It is inexpensive, with respect to what your time and property is worth, and the money you could waste getting someone of less quality than you had hoped to find to solve your groundwater problem will certainly cause you more grief financially and emotionally. Just punch up “angieslist.com” on google or yahoo.