All plumbing systems must be filtered or isolated as they leave or enter a BSL-4 space. This includes HEPA filters on plumbing vents. All liquid wastes go to the kill tanks. Solid waste goes to sterilizers or incinerators.
Liquid-effluent-treatment system
A kill tank using steam sterilizes all liquid waste before it leaves a BSL-4 building. Usually, doubly redundant tanks are used so that there is 100-percent backup. Liquid wastes are sterilized and pH-balanced before they are released to sanitary sewers. Because kill tanks are not located within BSL-4 facilities, pipes leading to kill tanks are usually double-walled to contain leaks.
From Biosafety Level 4 Labs Up Close and Personal
Sounds like the JV team is playing the bench warmers again...