Depending on who you ask this question to, their answers will be varied in response. Some will say that a food waste grinder should never be installed, and some would say it is acceptable. Those that say it is acceptable would say so with a few conditions.
If a grinder is added to the kitchen sink, the disposal should be used sparingly only. Also, if you are intending to put in a disposal, you should let your POWTS installer know so that a modification can be made to the proposed treatment tank. The treatment tank should be at least two-chambered and have an effluent filter installed on the septic tank outlet.
You should give serious consideration to oversizing the septic tank beyond the minimum code requirements. By following these simple procedures, your POWTS may experience premature failure due to the additional settling time provided by your treatment tank.