We have a drainage swale that we had installed by a landscaper in our back yard in Junction City. Our home is new construction (we moved in January of 2017), and the builder didn't realize how soggy the backyard got. When we had the landscaper come out and evaluate it (late spring/early summer of 2017), he advised that since the area had been farmland, and was known to be in a gray area of the flood plain, he suspected that we were simply getting water run off from our neighbors yards. He designed a plan that allowed for a small indentation with rocks and sand to retain the water and allow it to drain naturally to the water table. We discussed putting in wetland grasses but did not at that time. Since then, a small amount grass has volunteered in the bottom. But since this spring has started, we've noticed a high volume of green sludgy stuff that blooms out. I'm wondering if it's "algae bloom" which I've read is really a type of bacteria, and if it's being fed from the fertilizers our neighbors might be using. Where would I bring a sample of this stuff to be sure? Would putting it in a zip lock bag be sufficient? Would adding sand and perhaps more grasses at the bottom of the swale help filter that out if it is bacteria or even a more benign algae? It doesn't stink, but it gets out of control and I've noticed it bumps our histamine reactions when we try to clean it out.