This should really be done by your HR Department. The field employees probably know very little about conducting an actual compensation survey. What the average employee wants to know is "I heard the medics at the next flight program over get like $1.50 more per hour. That's so not fair because we do the same job in the same area and we should be paid more. How do we prove that we deserve a raise?" I'm not saying this is what is going on where you are, but I think it is the typical reason people bring up salary compensation surveys.
Comparing wages alone doesn't tell the whole picture. Are you prepared to find out the true cost of the benefits packages? What is the employers cost for your medical benefits? What is the employee's cost of medical benefits? Retirement match? Flex Spending account offered for medical or child care? Dental? Vision? Orthodontic care? Availability of adequate medical providers for different medical plans offered by different companies? Retention bonuses?
Have you asked HR? It's possible they already do them. If they don't, it is in their best interest to know what the competition is paying. Competition for HR is anyone who may hire away your talented employees or that you have to compete against to get their talented employees. If they are paying you too much (I know, that's never possible, right?) then they have passed the point of diminishing returns. This is the highest pay that they could where no matter how much more they paid, the quality and quantity of applicants won't change. Why pay $120,000/year when the same people would have done the job for $80,000? Also, they should use the survey to know if they are paying too little. Is turnover high? Is the company a stepping-stone to other jobs? If so, they could pay a more and decrease turnover, this would decrease annual training costs and save the money over all.
Back to the original question...talk to HR. That would be my advice.