I got a rare look inside a sewer manhole today, as a crew from Weston & Sampson, the environmental contractor checking sewer manholes for the city, came down my street. It’s part of the effort to reduce stormwater infiltration into sewers and vice versa. It was a two-person team in a small truck, with a tablet, a point-and-shoot camera and a very long ruler. They’re documenting the condition of the manholes with photos, and measuring the depths. If a manhole ever needs to be relined, it will be relined with concrete (not brick, which is what mine, at least, is lined with now), and it gets charged by the foot. They said they’re checking West Newton and near Crystal Lake currently, and the whole city gets done on a three-year cycle.
I was telling the police detail officer how, back in my business school days, I heard that one consulting company-type job interview question was “Why are manhole covers round?” Before she had a chance to think about it, the guy with the ruler had the answer – it’s the only shape that can’t fall in its hole. Although, surprisingly, he told me there are some triangular covers! Not sure if he meant Newton or the world.
I thought the manhole in front of my house looked to be in good shape – all the bricks seem to be in place. And it’s mostly empty now, but this is what your sewage passes through. If someone flushed, sewage would flow out one of these troughs into another. Somehow I thought it was all pipes!