Septic system design

We have an ongoing need for a geotechnical engineer to design septic systems for us in the State of Missouri. We can get soil samples to the engineer and then we need a timely turnaround. This will be volume work as we have 6 systems that need to be designed now. We are interesting in developing a relationship. Payment upon final county approval of design. Engineer will have to access county records showing property layouts to properly design the system.