Pressure washing, that's done annually here to try to prolong the inevitable. Its built right in to the maintenance contracts every bridge, every year, must be washed no ifs ands or buts. Its a big job and gets complicated with environmental rules. A lot of them out here are hanging over salmon spawning streams so its timed in the spring to be done around the best time frame when there's no salmon spawning and no fish hatching. Usually in April. Its a very busy time for the bridge guys there's a ton of bridges to be done in a short time frame. In May a lot of the streams are loaded with salmon fry so its a no go. March is too early generally still sanding and salting going on up high. A lot of them need piping rigged up to the drains or tarps to keep the wash water from directly entering the creek or river as well.
