siphoning

Characteristics of Tafgard

Environmentally Friendly

　　 1．Unlike other conventional drain systems, Tafgard does not need an alternate trench.
　　You can keep using one for a very long period of time.（See Kunisawa）
2. Tafgard’s capability to purify wastewater is superb as these various water analyses show.　
　　You will also notice that Tafgard increases oxygen in the soil.
　　Up to 99.3 % of fulvic acid, a precursor of carcinogenic trihalomethane, can be adsorbed by the soil.
　　17βestradiol, which is said to cause feminization, is totally adsorbed and decomposed by the soil.
3．Tafgard does not pollute the environment, including groundwater and natural waterways. Water in Tafgard spreads upwards and horizontally, unlike other conventional trench systems, utilizing siphoning (see pictures) and capillary action in the soil. (See the monitoring results of soil moisture content, electroconductivity, NO3-N, and T-P data)
4. The whole process is completely odorless.
　Gases are decomposed in the soil.
5. Tafgard is installed underground. Consequently, the surface area is available for planting.
　Plants cultivated in this area can safely absorb water and nutrients from the soil.
They also contribute to a great extent to evapotranspiration, thus enabling zero discharg of effluent.

Low Maintenance Cost

　　　１．Tafgard has no mechanical, moving parts, so it requires very little maintenance.
２．Tafgard can work for a very long period of time. We have an example which has been functioning over twenty years without maintenance.（See Kunisawa）
　　It is resistant to acidic, alkaline and corrosive conditions, and to deformation from physical forces, thus enabling it to be long lasting.　
３．Aerated soil does not need to be replaced. It can work as long as Tafgard does.
４．The Taisei septic tank utilizes a chain of bacteria, protozoan, metazoans and various kinds of enzymes, which come out naturally in the process. Consequently, sludge does not increase, thus it does not need to be desludged, minimizing the maintenance cost. The longer the food chain becomes, the more energy is consumed by respiration.
５．Tafgard, together with Taisei septic tanks, does not need any kind of power source and does not need a place to discharge effluent.

Applicability

Tafgard can be installed in many areas. It has been proven to be the most effective solution for homes, mountain lodges and public toilets in remote areas, such as beaches, national parks, ski resorts and campgrounds where there is no electric power source, where there is no place to discharge effluent, or in sensitive resource areas, like around drinking water supplies.
Performance is not affected by daily or seasonal variations. Tens of facilities where our systems are installed are closed during winter, but there's no problem when operation begins in spring.
They require no special maintenance work on resumption.

Footprint
　　　For a 3 bedroom household where about 450 gallons (about 1,700 liters) of wastewater per day are assumed, the required length of Tafgard is about 66 feet (about 20 meters).
　　　An area of about 480 sq. ft. (about 47 m2) is required.

Weeds on a Taisei septic tank at the same facility as the left.
As the surface of the septic tank is covered with a geotextile and soil, gases are decomposed in the soil and provide the plants with very rich nutrition: methane to carbon dioxide, and ammonia to nitrate nitrogen. The process is completely odorless.
The weeds were like the ones on the Tafgard two weeks before.

Weeds on Tafgard at a communal wastewater treatment facility.
This shows that effluent rises through the aerated soil and is absorbed by the weeds or evaporates. They thrive much faster than any other nearby plants. This helps evapotranspiration to a great extent and makes effluent discharge unnecessary.

The Taisei septic tank and Tafgard were added at this facility in March, 2008 in order to deal with the sludge from the existing . treatment system.
Sludge pumping has never been needed since the installation, thus contributing to big cost and CO2 reductions and less maintenance cost.