Good progress on your project, congrats. One caution is, how much weight can you put on a septic tank? Even light vehicles, like golf carts and ATVs, can have serious impacts on septic systems. Some septic systems are equipped with lids that are designed to withstand the weight of vehicles parked on top of them. However, even systems that are designed with reinforced lids can be damaged by vehicles, especially when those vehicles are particularly heavy or are left parked above the septic system for an extended period of time. Because septic systems are so susceptible to damage from vehicles driving or parking on top of them, there really isn’t any weight that’s safe to put on top of a septic tank. It’s best to avoid driving or parking vehicles on septic tanks at all to prevent any damage due to excessive stress and strain on your system. Just my two cents.
What will happen when any of the waste pipe are blocked how will you gain access to unblock them the other thing I don't like is how thin the general waste pipes are secondly at what degrees are those pipe laid at by right they should be at five degrees, from where I am at the waste pipe are laid at that in the ground and in future if some needs to dig how will they know exactly where the waste pipe's are????
When you concrete any pipe in if there is a leak what do you do ,do you do a pressure test first before you concrete any pipes in you need to have a pressure test done on all pipes so you will see if there is any leaks on the joints???