What is a Flout?

Flout stands for "Floating Outlet".

 It's a new way to flood septic system effluent into the leach field. It floods the distribution box with water well above the invert of the leach pipes, and insures an equal, fast flow of water down all legs of the leach field.

 What does it do?

 It holds back the water coming from the septic tank until enough is collected to flood the leach field. When the discharge cycle starts, all the stored water is fed to the D‑box and flows out every leg of the leach field. After discharging is completed, the septic tank water is held back until another full charge of water is collected. This gives the leach field time to rest and absorb the water that has flooded it. The flooding action insures the entire leach field sees water every time the tank discharges utilizing more surface area of the soil to treat the septic effluent than that of a standard trickling leaching system. If you have a 300-gal charge, 200' of 24" wide leach field, each square foot of trench bottom will average only .66 gallons of water per discharge.

How does it work?

 Gravity powers the system so no pumps are required. The Flout body acts like a boat hull and floats up on the surface of the water as the dousing tank fills. It is attached to the tank discharge pipes by a flexible coupling, allowing the Flout to lift off the tank floor in an arc as the water level rises in the dousing tank. The rising of the Flout prevents any water from flowing out to the leach field. When the water level is high enough, it over flows into the Flout body, causing the Flout to loose buoyancy and sink to the bottom of the tank. This action opens a direct path for the water to flow out of the tank and into the leach field. The flow of water fills the leach field pipes at a rate of 65 gallons per minute (per 3" outlet). When the water level falls below the edge of the Flout body, the water remaining inside empties (selfbails) by draining into the leach field, allowing the Flout to regain buoyancy and float up off the floor of the tank, once again blocking water from flowing out. The cycle now restarts as water trickles in from the septic tank and is held back from the leach field as the Flout floats up.

HOW IT WORKS
As effluent from the septic tank fills the chamber, the Float (Fig, I) is empty and buoyant and floats on the surface. Flexible connectors allow the Float to rise. When the effluent reaches the maximum level in the chamber, ii spills into a hole in the top of the float (Fig.2). This causes the float to sink. The effluent in the chamber discharges through the pipe(s) which exit the Float (Fig.3), dosing the septic field while providing equal distribution through each outlet, The chamber continues to empty down to the top of the Float (Fig.4). Then the Float empties and resumes floating to repeat another cycle(Fig.1).

Why is flooding and resting a leach field better than a distribution box?

 It encourages the soil microbes that clean the water by providing the best conditions for their growth. The soil/stone interface is flooded, then will dry out as the water is held back, keeping soil oxygen levels very high. The increased soil oxygen causes a population explosion of hungry microbes. An example of how fast these microbes can work is the speed a piece of wood will rot when it is allowed to constantly become wet and then dry out. The same piece of wood at the bottom of Lake Champlain or covered in a house wall will last centuries. No area of soil is ever totally saturated by septic effluent because the water is distributed evenly through the entire leach field. The volume of water per square foot of leach trench is less than a gallon. At the same time, the flood and rest cycle draws oxygen rich air into the leach field, feeding aerobic soil bacteria.

What happens in a standard trickling leach field ?

In a standard leach field, the water rushes into the septic tank, slows down and trickles out the tank outlet to the d‑box. The water flows through the lowest outlet of the d-box to the lowest point of that leg of leach field and into the soil. This area is constantly flooded by water until the soil is totally saturated and fails to absorb any more water. Anaerobic bacteria and fungus grow in the nutrient rich water around the leach pipe, forming a biomat that seals off the soil from the water. The water then backs-up to the next lowest spot in that leg and floods the new area until it too, fails. This constant, over wet condition prevents any oxygen from reaching the soil, allowing only slow acting anaerobic bacteria to grow, and killing off the fast acting aerobic soil bacteria. The old area is still too wet and never gets a chance to dry out. Eventually the entire leg fails and cannot accept any additional water. The water will fill that leg and then must back up to the d-box and flow from there out next lowest leach pipe opening. Careful leveling of the d-box will help even out water distribution, at least until the first ground frost cycle occurs, changing the d-box position. This resettling of the d-box by frost heaves each year ruins the best of leveling jobs. Two examples of just how powerful frost heaves can be are the damage heaves do to highways every year and the large rocks that appear in farmers field each spring.

What makes the flout better than a D-box alone?

 The flout can resist the effect frost heaves better. It has a larger area and is heavier than a d-box. It also tolerates an out of level condition, yet still will function properly. The high level of water in the tank and the fact the outlets are completely submerged during the discharge cycle, insure the discharge pipes are fully flooded the whole time water is flowing from the dousing tank. All the outlets will see the same amount of water pass through them, every time. The basic design uses one or two outlets but up to eight (even or odd) may be installed in a tank. This allows every leg of the leach field to have its own outlet from the dousing tank if desired. The Flout design also allows the placement of the leach field laterals parallel to the side of a hill, making an easy, practical solution to one of the most difficult leach field design problems. The overflow pipes act as a vent and will insure each outlet has an equal amount of water, no matter how far the leach field piping extends from the tank. This arrangement works even if the leach lines are lower or at a different levels from each other.

What makes the flout better than a Bell Siphon?

 It's easier and faster to install than a bell siphon and requires no special forms to build. Handling and onsite installation is accomplished using the same equipment required to set a septic tank and all work done at the same time the septic tank is delivered. The Flout tank can be leveled quickly and accurately. Any precast septic tank supplier can easily modify tank forms they already own, build a few and then return to building the regular products, on short notice. A contractor can install the flout tank in about an hour and wastes no time leveling the outlets of a d-box. The flout is glued in place inside of the dousing tank (at the precast plant) and delivered on site, ready to install in the ground. The excavated hole for the tank requires a simple flat bottom. 3" or 4" adapter connection pipes can be cast into the tank wall, as per your customer requirements and connection to the D-box is by the installation contractor. No more "grouting in" bell siphons on the job site. No priming water ever needs to be added to the flout for correct operation. Connection to the D-box is just as easy as gluing PVC pipes together. For those big jobs, any number of outlets may be installed in the tank, even or odd number as required. For large dousing applications, additional holding tanks can be paralleled to the dousing tank increasing water, volume per discharge.

The flout can be used to make a simpler mounded system

 This design uses a flout tank instead of pumps to flood the leach field. A smaller pump system can transfer the effluent from the septic tank outlet to a mounded leach field. The flout tank replaces the pressure pumps. No pumps or wiring are required at the mounded leach field installation, saving time, expensive pressure dousing pumps and the energy to run them.