Shouldn’t water and sewer lines go on the shoulder?

The in basket: Rick Willlams, a South Kitsap motorcyclist, says 

“All roadways have various utility covers, often left recessed, so they are sometimes a little hazardous. 

“Why are they put down the middle of the street instead of at the side of the road,” he asked. The pavement wouldn’t have to be dug up to repair them if they were off to the side.

The out basket: I went to Larry Curles, general manager of the West Sound Utility District, which provides water and sewer service to thousands of South Kitsapers, for an explanation.

Sewer lines are least expensive when they slope downward and gravity can move the waste, so pumps aren’t required, Larry said. The middle of the road or street provides the best chance that homes on both sides can have gravity flow. Putting the main on one shoulder of the other can mean pumping for houses on the far side.

Most importantly, though, the notion that mains are harder to reach for repair if they are under the asphalt is in error. In the years or decades after a main is installed, driveways, sidewalks, rock walls, large trees and other landscaping may be added by homeowners willing to add amenities in the utility easement.

After all those years, when repair becomes necessary, “you know you can get to it” when it’s in the roadway, he said.

Also, sewer and water lines must be 10 feet or more apart, and there are problems in being too close to underground electrical, telephone or gas lines, as well. Electrical and telephone often already are in the shoulder when municipal water and sewer is installed, requiring the new mains to go somewhere else even if the middle of the road wasn’t otherwise preferable. 

Larry ended our talk with a question he says is one of the first he ever encountered as an engineering student: Why are manhole covers round? Look for the answer in the next Road Warrior.

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