replacing septic tank with sewage pump?

[Ephraim]

After purchasing our "used" house, I have found many things that just were not clear when we signed the paperwork. We had an engineer inspect the septic system and it passed. However, several months after moving in, I tripped over a curved rebar sticking up out of the ground. After more inspection, it turns out that this is the handle of a septic tank cover on the opposite side of the house as the original septic tank.

It would appear that the original builder did not want to run a septic line across the house to service the other side and simply installed a second septic tank and drain field. It's not normally a problem, but the house does not have a garage and I want to build an attached garage. of course, the only two location I can build now have a septic tank and drain field located there.

Is it a viable solution to replace one of the septic tanks with a sewage pump and pressure line to dump into the other side of the house? to do this, I would need to cut the septic line before it enters the second tank and route the drain line about 16' to an area outside of the garage footprint where I would install the sump and sewage pump and then run a pressure line approximately 70 feet to the first septic tank.

any ideas?