A friend of mine used to have a gig draining septic tanks and he told me once that it’s rare to get through a day without throwing up on the job. And it’s that sound of vomit that kicks off Septic Man, the new film from director Jesse T. Cook (Monster Brawl) and writer Tony Burgess (Pontypool). The vomit quickly leads to shit, piss, rotting skin, dead bodies, and a slew of other grotesqueness bubbling up in the sewers. Their fecal matter serves a purpose though, as the filmmakers ambitiously try to deliver a message about class struggle and how the well-to-dos make the working class eat shit. The subtext remains murky, however, as the story quickly starts to tread water.

In the Canadian town of Collinwood, a vicious stomach virus has made its way into the water supply. The town is evacuated, except for septic expert Jack – a self-proclaimed “civic-minded shit sucker.” He’s asked by a mysterious, vampiric G-man to stay behind and get to the bottom of the contaminated water. He’s reluctant at first, but he has a kid on the way and the hefty cash payoff for the job is too tempting. Jack is blue-collar through and through – like the living embodiment of a Springsteen song, but with more poop. It’s easy to root for him.

Jack ventures into the sewage treatment plant where he finds himself the target of some sadistic game played by its bizarre mutant workers. Maybe they don’t work there and just live in the treatment plant? I dunno. Quickly Jack is trapped inside the heart of diarrhea darkness and repeatedly tormented. After a couple of nasty spills that leave him completely submerged in the filth, Jack’s body begins to transform in graphically hideous ways, like Toxie. The makeup work is really stellar – Jack looks like he smells so bad!

The big problem is that once Jack is inside the septic tank, the film stays there. He constantly thinks about how his wife Shelley (Molly Dunsworth – Hobo With a Shotgun) is pregnant and even hallucinates about it. The strange inhabitants of the treatment plant do a lot of whining and argue amongst themselves. So while they quarrel, Jack reflects on his life and unborn baby in the septic tank. This is essentially 90 percent of the movie.

The film’s climax is moving in a way, as Jack makes a tough decision. That’s about it in the dramatic department though. Keeping Jack confined to the tank restricts any kind of underlying class statement Cook and Burgess were trying to make. As a filthy FX gross-out, the film is a homerun and achieves some laughs in the process. It’s a clear mix of Burgess’ moody, intense tone and Cook’s B-movie sensibilities, but no common ground is ever met. It’s a fun, intriguing concept that sadly never escapes the mire of monotony.