Rigsby's Septic Tank Cleaning

The men (2) seemed knowledgable about septic tanks, dug down through the soil to find and open the concrete top of the tank. The tank was full of liquid, mostly ( I assum) from a recent rain that had flooded the yard and over the top of the tank clean-out pipe (which had been broken). They used a 120' hose from the truck on the front driveway to tank in the back yard. It wasn't clear to me how much they pumped out or why they stoppped when they did, but all seemed to go well. I was disappointed that they did not completely close the lid as it was before opening. Instead they asked for some shingles to cover the opening they left (appx 1/2 inch crack) before shoveling the soil back in the excavation.It was just dumped in with no attention to smoothing it our or making the it level or neat. I cut a piece of tar paper (roofing underlay) for them which was placed to cover the opening crack left in the top of the tank. I think they could/should have slid the concrete covering completely closed. Otherwise, ground water can seep into the tank, since this area of the yard floods during a heavy rain. I have since repaired the broken stand pipe. It is not clear to me that the tank is working properly, as the water lever in the stand pipe is currently higher than usual, and no rain has occurred to account for it lately. I have been giving it extra chemcal treatments. If the level keeps rising I may have to call them again to clean it out.