I was just wondering if you build your kitchen next to your home can you just tie in to your existing septic tank/system or do you have to put in a new one?

Around here, in Central/Northern NJ (as far as I know) the size of the septic tank depends on the number of bedrooms in the house and when I inquired about starting a home-based bakery business, one of the numerous requirements was that a grease trap must be attached to the plumbing (the darn thing costs about $750. Don't know if that includes installation; probably not!).

It depends on the size of the tank you have. Our house was build in the 80s and they didn't require them to be as large as they do now, so we're having to put in a new one. Also, the water has to drain down hill, so if yours doesn't, they might make you put in a special pump.