I am building a 40x40 shop, and i want a office in there. I am on a septic can I tie in with a exsisting septic system?

 

Can you tie into the existing septic?......Yes, from a mechanical point of view.

Should you tie into the existing septic?.....That requires some info.

Does you local Health District allow it ? If it is legal to do and you have the proper approvals, then its not that big of a deal.

Depending on where the shop is to be built, you can tie the new sewer line either: into the existing sewer line from the house or directly into the septic tank. If you go into the tank, make sure a new inlet baffle is provided. If you tie into the line, just use the correct type fittings....dont forget a cleanout or a few of them.

The next part is elevations. As long as the shop is higher than than the existing sewer line and septic tank, the above will work. If it is lower or there will not be enough pitch in the pipe to the tank, then it needs to be pumped. I'm not a big fan of pumping raw sewage. It always leads to problems. But, since this will only be a shop and will see limited use, a pump may work just fine.