If part of the evaluation is a perk test, you don't want to saturate the drainfield before they do it. They would dig a little hole, fill it with water, and see how long it takes to absorb into the soil. Find out what the test involves. May be best to minimize water volume for a while. If you've had the tank pumped out every few years, not over done the water volume, and not saturated it with grease, it should be OK.
