A literature survey indicated that riparian buffers have a large capacity for nitrate removal via denitrification. But in much of Iowa and the Midwest this removal mechanism is limited by the lack of water flowing through buffers as groundwater by the prevalence of tile drains out letting directly to surface waters. This idea was tested by re-plumbing a tile outlet to route some of the tile water through an existing riparian buffer and measured the amount of water redirected and the fate of the nitrate contained within the water.