If you have a septic tank, you should get it pumped every 3 to 5 years. They can back up and cause problems if you don’t keep up with them. You can see these problems in water pooling around the drain pipes or a gurgling sound coming from the toilets when they are flushed.
But I digress.
Septic work requires a truck designed for the job and is impossible to do yourself. But septic pumping is also not terribly expensive, running between $200 and $500 in most parts of the country.
You would be well served to have a green cap placed on top of the tank rather than move all the dirt back and try to get the grass to grow over it. These cost about $125 but they will allow access to the tank without digging and will not leave an unsightly dirt spot in the middle of your lawn. The cap is hard to see unless you are right on top of it, so this is a great solution.
A site that goes into great detail with everything associated with septic work is Septic Pumping Richmond. They have been in business for years and are experienced with the cleaning and installation of septic systems. Check out the site for everything you need to know about septic systems.