Design & DIY

Can I put a privy on top of the septic tank?

My cabin has no plumbing, but I am in the process of building a four-season home on my lot, so I have put in a proper septic system. For now, can I put a privy on top of the septic tank and use my system? -Joseph Cooke, via email

Directly on top? Well, no. “Dropping an outhouse right on top of a septic tank is probably not going to fly with your regulator,” says Mark Green, the chief building official for the Leeds, Grenville & Lanark District Health Unit. For one thing, this violates the Ontario Building Code (septic tanks must be at minimum 1.5 metres away from any structure). And, since it wasn’t designed to support an outhouse, you risk damaging the tank. While vault-style privies exist (such as the toilets that you’ll find in provincial parks), those tanks are reinforced to hold up the buildings that sit on them. 

But check with your local regulator and the septic system manufacturer—you may still have options. Your building department may issue a conditional permit for a short-term, temporary solution. For example, using a pail privy with the system, says Green. “When it fills up, you pail the waste over to the tank and dump it in.” The problem with this strategy—never mind the fact that it ranks fairly high on the Disgust-O-Meter—is that septic systems really need waste and waste water to function. With no water from sinks, showers, and washing machines going into the tank, eventually yours may malfunction. (Plus, it’s not wise to frequently open the top of the septic tank and inhale those fumes.)

Sandy Bos, the on-site sewage system inspector for the Township of Muskoka Lakes, says that another option is to put the privy near the septic system and install a flush toilet, plumbed to the tank. “People do it. I’ve seen it done,” says Bos. “It’s certainly a lot cleaner and smells better.” Better than lugging around a bucket full of sewage? We sure hope so.