A passive filter cell having a basin with a floor and two or more vertical or upright sidewalls forming chute or container having first or left sidewall, second or right sidewall, and third or back sidewall, and fourth or front downwardly curved sidewall, an inlet positioned proximate a top of the fourth or front sidewall and an outlet positioned proximate the top of the third or back sidewall, wherein the floor is configured angled from the fourth or front sidewall to the third or back sidewall, discharge pipe positioned proximate junction between the floor and the third or back sidewall, and lip configured to extend from the top of the third or back sidewall into an interior of the basin.