Is it possible to limit the number of people in my rental property if it is on a septic system?
As long as you comply with all relevant housing laws, you can limit the number of tenants in your rental property.
You should check your state and local health and safety codes. Even if they support your limit on occupants, you cannot set unreasonable low figures to reduce noise or wear and tear.
Unless you have a legitimate reason for a lower number, landlords must allow two people per bedroom.
Local occupancy standards may allow even more people in your rental than federal law. Your occupancy policy may be considered discriminatory if it limits the number of tenants for reasons other than health, safety, or real legitimate business requirements.
Septic companies should provide you with a written report describing why they recommend a particular solution.