We are supposed to have a good rain after the weekend. After they fill the trench, and they are done you can get some old shoes and go do a happy dance on the mounds of clay. That will compress it down more. After the rain wait a day or so for it to dry a little and do another happy dance or a good Irish Jig and stomp it more.
If you look near the center of this photo you will see a guy in a hat gluing the last of the connections to our new sewer line. That was a BIG hole. They filled it in, but had a mound left over. We did a lot of stomping and watering in. It is all better now.