Hi, I live near the lake and built a new house. After a year, I am getting lot of water in sump pit, ground water. Instead of making second sump pit on other corner of the house, what if I join the sump pit with ejector pit. getting new sump pit is costing $ 6K. The sump pit and ejector pit are closely placed, I could dig few inches and join the two? Basement as of now is unfinished, that ejector pit is not used at all. I may finish basement and the bathroom as well in near future. I am really confused and need to know the pros and cons of joining the two. Legal aspect I can check with city, I am just seeking technical suggestion. Thanks in advance and I would really appreciate the feedback. Have a blessed day.

a sump pit is usually a flimsy thin plastic container that is not meant to be water tight.
sometimes multiple holes are punched in it and multiple rain leader pipes stick thru the holes and are not sealed at all where they penetrate.
an ejector tank is a much more sturdy tank that is meant to be water tight.
most commonly there is a single hole predrilled in the side with some sort of well sealed fitting attached. this is the only penetration and it is meant to accept a house drain pipe.
the hole is drilled at a predetermined height so as to work most efficiently with a sewer ejector pump.
so, if you want to use the ejector tank for ground water you will have to carefully drill a hole where you want it but that hole MUST be able to be 100% sealed if you want to change back to a sewer tank in the future

So when I make the bathroom in the basement, do I need to disconnect the connection between sump and ejector pit?

If the ejector pump discharges into the sewer system, chances are that is not allowed. The city/county wouldn't want to treat the ground water.

So when I make the bathroom in the basement, do I need to disconnect the connection between sump and ejector pit?

Where does the ejector discharge now?

yes you will. you will also need to patch the hole you have made in the ejector tank 100% leakproof.
any seepage out of that hole or back into the sump tank will be raw sewage.

steve.. the current ejector tank has no ejector pump in it.
he just wants to use the ejector tank a a second ground water collector that spills over into the sump tank.

Sewage under your slab is not a good thing. Could make for a very stinky house. Sump pits and their leads are generally not sealed.