Tuesday, October 11, 2011

Stormwater adventures with Wes

Yesterday was a field training day for our new stormwater compliance intern, Wes. We’re teaching Wes to make observations about stormwater best management practices at construction sites, and to assess whether systems are in place to prevent sediment from flowing into storm drains, and on to nearby streams and wetlands. We planned a route to visit several construction sites, and our first stop was the upper terminus of Birch Street, the entry way to Galbraith Mountain - a neighborhood that keeps expanding up a steep hill.

As we drove up the hill, we noticed each storm drain had a filter, and the road surface was very clean. We parked just before the end of the paved road. Looming in front of us was a large diesel tank, and a bulldozer parked right next to a storm drain. We felt small, in our white prius marked “RE Sources - be part of the solution” on the back and sides of the car. Nobody was around. It started to rain. Sitting inside the car, we looked uphill at the construction site, noticing steep uncovered slopes, large newly graded areas, piles of wood mulch and soil, a few feet of silt fence, and narrow bands of wood mulch between the road surface and the exposed soil areas.

I pointed to the large cut bank, which had trees at the top and a near vertical drop down to recently graded exposed soil, which sloped down and ended next to a brand-new home. The home had a “for sale” sign and a recently installed bright green lawn. Wes is a geology major. He stared at the cut bank, and I stared at the house. A band of wood mulch had been placed between the bright green lawn and the uncovered soil. “What do you think about that house?” I asked. Neither of us would like to live in a house under a steep bank like that. “Notice anything else?” I asked Wes. I pointed to the bulldozer and the fuel tank. I told Wes that fueling heavy machinery right over a storm drain just wasn’t right, and that I would send a photo of the fueling situation to our local Department of Ecology stormwater inspector. I took a photo of it, and we got into the car.

But the car wouldn’t start. For half an hour we tried, gave up, and called a towing company. I was panicked. My bike was miles away, and I’d never needed a tow before. We had an hour to wait, and it began to rain harder. “Let’s go look at stormwater!” I suggested to Wes. We set off on foot.

We walked down the hill, looking at water flowing down the street. It was clear, so no sediment was moving off the site today. Sandbags had been placed uphill of many of the storm drains, slowing the water down, and allowing sediment to settle. We looked at the storm drain filters. A little bit of sediment had built up around some of them, and they looked like they should be changed. Plants were growing in one of them! Where they working? We think these are designed to remove large chunks, not fine sediment, so we weren’t sure. We walked around the corner to a different construction area, noticing a low area, with a large construction site above it. Large rocks had been placed in one area, and a wide band of wood chips had been placed between the new road and the exposed soil. Two straw-filled wattles were placed diagonally across the new road. I pointed to the low area, and said “I bet there’s a creek down there.” From the sidewalk, we peered into the bushes, but we couldn’t see or hear any water.


We walked along the paved road to the bottom of the hill past new houses, one of them sporting a sign stating “backs to creek.” At the bottom were two stormwater ponds, surrounded by chain link fence and twenty-foot tall alder trees. The water in the ponds was clear, and we saw nothing noteworthy. With the exception of the fuel tank next to the storm drain, we decided that the contractors working here knew what to do to prevent sediment from moving off site.

The Department of Ecology stormwater inspector agreed with our assessment, and required that the fuel tank be moved away from the storm drain. The tow truck arrived. It was sad watching our little car get towed away, with the words “be part of the solution” above its rear bumper almost dragging on the pavement.

2 comments:

  1. Good work sleuths. Glad to see so much of that site was done well ... the wet season does sort of sneak up. Hey Wes - ask her about the car keys ... =:<)

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  2. Seems like it was a fun little project! nice, sturdy inlet filter you got pictured there!
    -Jon

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