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Oasis Design Specialties

A description of high performance, growing edge designs available for clients with appropriate contexts.


Pioneering designs involves excitement, extra work, and a bit of risk. We've been fortunate to incubate a large number of designs from conception to pioneering to widely acknowledged best practice and inclusion in building codes.

Eco luxury bathing chamber

The eco luxury bathing chamber is a series of shower stall improvements which yield increased bathing comfort with drastically lowered water and energy use. It is a rare case of a design that saves energy, water, money...and is more comfortable; a true instance of sustainable hedonism. At this point, this design is fairly well proven, just tinkering with refinements.

In an eco luxury bathing chamber, two people can have a half hour luxurious bathing experience and finish up with a huge water fight—with the same energy and water one person uses in a five minute military-style shower under an anemic low-flow showerhead.

The modifications stem from one key realization: bathers need only a small amount of water for getting clean, but (without realizing what they are doing) use quite a lot of hot water to warm up, as evaporating water and convective air currents conspire to rapidly cool them.

In a conventional shower, heat is being lost almost as fast as it is added. It takes a long time to raise one's core body temperature to the point where you can shut off the water, dry off and get your clothes on without getting uncomfortably cold. People are (understandably) reluctant to get out until that point; bathing is as much about comfort (if not pleasure) as cleanliness.

Conventional shower stalls are designed like wind tunnels; the only way to maintain comfort is to via a continuous stream of hot water, most of the energy in which ends up warming the drain pipes, fogging the windows, and condensing in the bathroom (potentially creating mold issues).

The eco-luxury bathing chamber is designed to reduce heat loss by convection, conduction and radiation, similar to a steam shower. It can optionally include floor heating. It can be designed to be used like a conventional shower, or for Japanese style bathing, with the water heated inside the thermal envelope of the bathing chamber, providing a sauna-like experience.

It is dried by ventilation between uses.

This design is still evolving and has many custom elements, so at this point it is expensive to have made.

It is appropriate for a high end green home, hotel, or high use installations, where the energy and water savings can add up. The location must be an easy commute from Santa Barbara, California.

Larry Schlussler of Sun Frost deserves much of the credit for this class of efficient shower innovation.


Gravity flow greywater greenhouse

A gravity flow, passive solar greenhouse provides supplementary heating of the home, winter greens, and year-round effective greywater treatment, with simplified maintenance relative to a pumped and filtered system. This design is best incorporated in the original construction of the greenhouse, and requires the house plumbing to be situated at the right elevation. It is low risk.

This design would be appropriate for any installation where the greenhouse soil surface is sufficiently below the level of the greywater supply, and the effluent flow is a few hundred gallons per day or or less. The colder the climate, the more appropriate an indoor greywater system. The location must be an easy flight from Santa Barbara, California, which probably indicates a high-altitude, rather than a high latitude system.


Green septic system

A green septic system enables 100% of household wastewater to be reused for irrigation of fruit or ornamental trees. The system provides exceptionally high treatment effectiveness, much higher per square foot treatment capacity, and should have much longer life. This design may need to be protected against burrowing filling the chambers.

An Oasis original design, a green septic system is a fusion of state of the art passive septic system technology with Oasis's branched drain flow splitting and landscape/ orchard irrigation.

This is a new design, but the components are proven individually and the preliminary results are good.

A green septic system is suited for:

It should be permittable in most areas under the septic code, with the addition of a cooperative engineer's stamp. This system doesn't usually make sense where you're obligated to hook up to a sewer.

The location must be an easy commute from Santa Barbara, California. The cost should be not much more than a conventional system, in some cases possibly even less.

More details...


Comparison of conventional system and green septic system

Green septic
Conventional septic
Distribution of effluent
Even, controlled Unpredictable, concentrated
Highly effective from aerobic and anaerobic microorganisms shallow in the soil profile; plant roots absorb nutrients Moderately effective from anaerobic microorganisms deep in the soil profile, nutrients pollute groundwater
Water reuse
Reuse of all household greywater and blackwater facilitated by predictable, even dispersal of effluent Impractical; some plants receive too much water, most receive none. Roots can clog perforated pipe.
Inspection and service access
Provided to every part of the system Generally little or no access
Evapo-transpiration assist
Significant Insignificant
Long term acceptance rate (LTAR)
High, due to relative absence of bacterial biomat formation, action of soil macro fauna to till soil and keep it open Low, due to anaerobic conditions which seal the surface with a bacterial biomat (slime layer) and deter soil fauna
Action on failure
Pressure wash roots out and clean soil surface Abandon system and make a new one elsewhere on the property


Even distribution of effluent

The key difference is controlled, even, gravity-powered dissemination of effluent.

In a conventional leachfield, the majority of the effluent discharges through the first few holes in the perforated pipe, or the lowest few holes. This leads to progressive failure: a bacterial biomat forms in the small area where the effluent concentrates, lowering the permeability by approximately a factor of 100. The effluent then flows over this this small, overloaded area and overloads the next area, like a cigar burning down.

In contrast, the dosing distribution box, zone valves, and flow splitters in this system discharge the effluent in a controlled, long term reliable way to one discrete outlet per infiltrator, providing more even distribution than any other gravity-powered system of which I am aware. This dramatically decreases the likelihood of progressive failure originating at a small overloaded area. Wide dispersal also greatly increases the contribution of evapotranspiration to removing effluent from the soil, and the reuse utility of the water. Instead of one overloaded plant and several dry ones, all will receive the same amount of water.

Evapotranspiration assist

Evapotranspiration assist is a known aid to the capacity of leachfields—until they clog from root intrusion. Perforated pipe, with openings of 3/4” or less, is easily clogged by roots. The large, open gravelless infiltration galleys specified for this system (“infiltrators”) have proven highly resistant to clogging from roots in their application in evapotranspiration beds and between rows of grapes in vineyards. It is easy to see why—each linear foot of infiltrator has 432 square inches of outlet, compared to about an one inch per foot of perforated pipe. The roots have no incentive or means to grow through the air to the actual outlet a foot above the infiltration surface. 


Unlike most leachfields, this system will incorporate design for total serviceability. Covered inspection/ access ports will be provided to each infiltrator and its inlet, all leachfield distribution piping, flow splitters, and the distribution box. this one will have complete serviceability.

In other infiltrator systems which do not incorporate the even loading feature this one does, the original perk rate has been successfully restored by pressure washing the biomat off of the earth floor of the infiltrator.  Our plans designate a location for a 100% replacement area as required by code, but it is exceedingly unlikely this will ever be needed.

Leachfield zones

The distribution box will be outfitted with valves which can be used to move the effluent between infiltrator zones. Experience has shown that diverting effluent for just a month causes any biomat which has formed to die, restoring the percolation rate to nearly its original value.



If you would like one of these designs in your project, please  Email us .