My city (Washington, DC) is now requiring that all construction sites where the earth is disturbed have a sediment tank on site, so that if water has to be pumped out of an excavation the sediment can be removed before the water is dumped. While I support this — it’s important to keep runoff out of our sewer system and waterways — it’s a pain. I looked into buying a tank and it’s about $2,000, requires two people to carry. They’re about 8 feet long so they take up space on the job site and are hard to store and transport between jobs.

I happened to be walking past a site today and noticed a homemade tank, I’ve attached a picture. It’s made from three blue plastic barrels and PVC pipe. I will check with the city but I presume it was accepted by the inspector. I like this design because I can take it apart for moving and storage, and it will be cheap — I can get the barrels on Craigslist for $20 each. 

The design looks pretty simple, but I’m wondering if  anyone here has experience with sedimentation tanks and any thoughts on construction.

Thanks.