Toilet waste and regular shampoo water can go to a septic system as long as it's less than 10,000 gallons per day. However, the wastewater from chemical discharges (for example; perms and coloring) needs to be stored in an industrial wastewater holding tank certified by MassDEP. Dischargers have the choice to either direct all their sinks to a holding tank or have all of the chemical wastewater go to a special sink that is separately plumbed to a holding tank, with staff educated to ensure they only use that one sink for these processes.
If a discharge of industrial wastewater to a septic system is being discontinued, then in addition to complying with requirements for holding tanks, a beauty parlor that has been discharging industrial wastewater must notify MassDEP's Underground Injection Control (UIC) Program that the discharge is being closed.