Abstract: A biological waste treatment assembly used between a septic tank and a drain field. There is an upper chamber containing a trickle media bed for aerobic treatment of the effluent, and a sump positioned beneath this. The fresh effluent from the septic tank drains into the sump, and is drawn from this and pumped upwardly through a conduit by a submersible pump. Compressed air is introduced at the base of the conduit so as to aerate the effluent. The conduit is formed of UV-transparent tubing, and this is helically coiled around an ultraviolet light source which serves to destroy fecal colliform bacteria in the effluent. The effluent is then discharged via a spray nozzle onto the upper surface of the aerobic treatment bed, and migrates downwardly through this to a collection pan. A down tube drains the collected effluent directly to a relatively oxygen-free layer in the sump, where secondary anaerobic treatment serves to denitrify the products of the aerobic treatment in the upper chamber.

Abstract: A cover assembly for use with a base structure such as a hot tub comprising a cover member mounted for rotational movement to the base structure by mounting arms.The mounting arms are arranged relative to the cover member so that the cover member travels along a path from a covering positioning to an open position, this path having a first path portion extending between the covering position and an intermediate location area of the cover member, and a second path portion extending between the open position and the intermediate location area.The cover member is arranged relative to the mounting arms in a manner that with the cover member on a first side of the intermediate location area in the first path portion, gravitational force on the cover assembly tends to move the cover member to the covering position, and with the cover member on the second side of the intermediate location area in the second path portion, gravitational force on the cover assembly tends to move the cover member to the open position.

Abstract: A cover for a pool, hot tub or the like wherein the pool structure has an upper perimeter portion defining a pool area where water is contained. The cover has a first upper flexible sheet member having a first central portion and a first perimeter portion and a second lower flexible sheet member having a second central portion and a second perimeter portion. The first central portion of the first upper sheet member is separated from the second central portion of the second lower sheet by a support member. The support member has a sufficiently large vertical dimension to support the central portion of the first upper sheet member such that the first upper sheet member extends radially outwardly from the first central portion to the first perimeter portion at a moderate downward slope so that water and debris that fall on the cover move outwardly and downwardly from the first central portion of the first upper sheet member.