High Occupancy Toll (HOT) Lanes
I-495 Capital Beltway Expansion Project
Upstream from Lake Accotink
Documentation of Sediment Control Failures
Coons Branch tributary

August 12, 2009

Here are pictures from the Coons Branch tributary of Accotink Creek showing a healthy creek turned into a muddy channel:
081109 Photos - Coons Branch sediment pumping

Recently, this tributary has been releasing sediment into Accotink, even during dry periods (usually these tributaries run brown with sediment during rain events, but otherwise run clear), so Philip Latasa and I decided to investigate. What we found was surprising, even though I'm used to seeing sediment control failures as a result of the 495-HOT construction. This failure was relatively trivial, a small mistake, or an act of laziness, and the contamination, relative to the large amounts of sediment I've watched wash into Accotink over the last year, not that serious. Just one little tributary, turned into a muddy slop.

100 yards upstream, the Coons Branch runs clear - you can see the rocks at the bottom, and small fish darting between them. If I explored a bit, I'd probably find crawfish, and some waterbugs. Upstream are suburban developments, built 20+ years back. The banks are cut 4-6 feet deep, like a ditch, due to the quick floods from the roads and houses upstream. But the water runs clear, and this is still decent habitat - lots of birds around, and a nice little forest.

Coons Branch runs into a culvert under the 236 cloverleaf. VDOT/Fluor has been doing construction along the road there, grading with bulldozers, which has left a long V of a ditch, that follows the access road to 495 north. The ditch is bare dirt, which means that any runoff from a rain event will quickly become mud, and be washed downstream. There are a series of "check dams", low barriers of gravel across the ditch, that will settle out some of the sediment before it reaches Coons Branch - it's better than nothing, but doesn't do much, in a real rain. There's water running through the ditch now, even though it hasn't rained recently - probably groundwater flowing from somewhere upstream in the construction site.

The ditch meets the Coons Branch at the culvert. It's hard to figure out what exactly is happening - there's a long hose that runs downstream through the culvert, that's connected to a running generator, during work periods. We visited the site after work hours - the generator had been removed, and there was a trickle of water coming down the ditch. On the other end of the culvert, in one of the clover-leafs of the 236 interchange, the hose ended, in the tributary, which was suddenly opaque with sediment, and the stream channel choked with mud and sand - a dramatic change from the clean, clear stream, 100m upstream.

Puddles not directly connected to the flow of the stream were perfectly clear, which told me that the sediment in the tributary was due to a recent event. I didn't understand how VDOT could have been pumping sediment-laced water directly into a tributary, until I found a large (20 square foot) silt bag, on one of the banks. These are supposed to be used to filter sediment - water is pumped into the bag, and the sediment trapped within, while the water seeps out. In this case, the hose wasn't connected to the bag, so all the muddy water pumped by the generator had gone directly into the stream.

There's no way to tell how long this has been going on - maybe just today, but I've noticed sediment coming from Coons Branch several times prior. The amount of mud in the stream is dramatic - it's a mudpool now, anything that was living here before is dead, and the sediment will over the next few months and years be washed into Accotink Creek, to choke and kill life there. But most of the sediment could be from other activities - the clearcutting and bulldozing, the rain events that regularly overwhelm the sediment control structures in place. Once the sediment's in the stream, there's no way to get it out.

So, a trivial event, a small mistake, a small tributary, a bit of mud in the watershed. I take pictures, and report it to VDOT, Fluor, and DCR. They'll send someone out to fix it the next day. Maybe they'll start monitoring it better. But it's just one small mistake. If they'd been pumping this sediment-laced water onto 495 for 6 hours, there'd probably be a criminal investigation, because of the serious danger posed. But this little stream doesn't matter. It would be possible to do things more carefully, more responsibly, but that would cost money. It would cut into profits. It would make the project more expensive. And this tributary's not worth it. Nor is Accotink Creek. If I wasn't documenting and reporting these problems, they wouldn't exist.

I've spent a lot of time documenting these failures - crawling through underbrush, getting ripped up by thorny vines, wading through mud. I often wonder why I keep going back to these depressing places, where I always find new failures, new pollution events, instead of going somewhere positive, somewhere that isn't being bulldozed and smothered - kayaking on the Potomac, or trail running. But I feel a sense of responsibility to this place, and am committed to improving the situation, or at the very least, documenting it.

When I started taking pictures and reporting problems, I thought they might get fixed. I thought VDOT and Fluor might go back and build their controls strong enough to stop sediment from entering the watershed. Fluor is a large multinational company - from their website, "Fluor takes on the toughest challenges in engineering, procurement, construction, maintenance, and project management.". But apparently, they haven't mastered sediment control yet. A VDOT spokesperson claimed that "no sediment would enter Accotink Creek", before the bulldozers started. That hasn't been the case. Maybe they could have built this project right, but it would have cost them more money. And it's just a tributary, just a creek, just a watershed. I've been told that the E&S controls have been built to or better than the legally required standard. But I am not impressed.

To their credit, VDOT, Fluor and partners are decently responsive now. When I go back to sites that I've reported, I usually see repairs, and sometimes improvements. Often it looks like the repairs won't hold up to the next significant rain event, but that doesn't matter. If they get knocked down, they just need to be repaired within 24-48 hours. As long as they're built to the defined standard (a 2-year storm), it's legal. Based on the number of failures I've documented since last September, we've had quite a few 2-year storms in the last year. I don't know how many, because apparently VDOT and Fluor don't actually track that. But as long as they do repairs within the specified time, everything's fine, even though we all know they're going to keep failing.

I wonder about why so many areas were bulldozed, and then just left as exposed slopes of dirt, waiting for rains to wash them down, for almost a year now. If they'd left the trees in place until they were actually ready to start construction, there would be a much shorter period during which sediment failures could occur. One theory is that they bulldozed everything at the beginning, in order to preempt any public opposition, which seems possible - by the time the public realized what was happening, all the trees were down. If that's the case though, a successful PR tactic has resulted in significant additional degradations to the watershed.

I wonder about how much it more it would have cost to build the sediment controls right from the beginning - 5%? 1%? Would that have been cheaper, than the number of repairs they've had to do over the year, including the time lost to the stop work order? I think about what it would cost, to actually mitigate the resultant damage to the Accotink watershed, already damaged by so many other construction projects. I think about how long this sediment will be in the creeks and tributaries, moving downstream with the current.

Contact the investigator, Kris Unger E-mail.

Contact Friends of Accotink Creek, E-mail.

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