Also remember for those of you that wash houses and Decks you also need to check for sump pumps in basements. If you strip decks and run a lot of stripper and chemicals into the ground they will not magically disappear and usually end up in the sump sytem, and this also includes old stains. Most sump systems will be pumped into a local ditch, canal, or other storm drain (sewer) not sanitary sewers in most cities. Sump fills up with your chemicals, stains, and alot of water and continues to empty itself into the ditches, canals, and streams.