Wastewater systems, wells: Watchpoints
The wastewater company will install the system, possibly under the supervision of your site assessor to ensure compliance with the planning conditions as set out in your grant of approval.
A digger will in all likelihood be required, to dig trenches to connect the pipes from the house to the septic tank and to dig a hole for the septic tanks and other treatment systems including the percolation area. Check in advance who is to arrange for the digger and who will operate it. A groundwork contractor is likely to brought on board.