In this video

Using the wheelbarrow, backfill the excavated area around the newly installed septic riser with the previously removed soil. Gently compact the soil to remove large air pockets, but avoid excessive force that could damage the riser. Then, apply a layer of fresh topsoil, spread grass seed (such as EZ Seed), or lay sod over the area to blend the riser into the surrounding landscape. Finally, water the newly backfilled and seeded/sodded area thoroughly to promote growth and help the soil settle.