2 tank types from TUF-TITE.
Riser
TUF-TITE risers bring the septic tank access to grade level so you do not have to dig up the yard for pumping. The 20-inch diameter is the standard size for most residential tanks. They stack with gaskets between sections and the flat lid sits flush with the ground. Strong enough to handle foot traffic but do not drive over them.
$30 - $60 per section (varies by height)
Riser
The 24-inch riser is used when you need a wider opening, often for tanks with larger access ports or when the pumper needs more room to maneuver the hose. The domed lid sheds water better than a flat lid in areas where surface drainage is a concern. Same stacking system as the 20-inch but with more clearance inside.
$40 - $75 per section